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Solids circulation rate measurement in a circulating fluidized bed Burkell, James J. 1986

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SOLIDS CIRCULATION RATE MEASUREMENT IN A CIRCULATING FLUIDIZED BED  by  JAMES J . BURKELL B.A.Sc., The U n i v e r s i t y o f B r i t i s h Columbia,1984  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE  in  FACULTY OF GRADUATE STUDIES (Department of Chemical  We accept t h i s  Engineering)  as conforming  to the r e q u i r e d  standard  THE UNIVERSITY OF BRITISH COLUMBIA APRIL, 1986 © JAMES BURKELL,  1986  In  presenting  requirements  this thesis  f o r an a d v a n c e d  of  British  it  freely available  agree for  that  Columbia,  I agree  degree that  f o r reference  permission  scholarly  in partial  be  at the  University  the Library  s h a l l make  and study.  I  f o r extensive  p u r p o s e s may  fulfilment of the  copying  granted  of this  for  that  copying  f i n a n c i a l gain  or publication  s h a l l n o t be a l l o w e d  of this  C.h&vn \ CO j  The U n i v e r s i t y o f B r i t i s h 2075 Wesbrook P l a c e Vancouver, Canada V6T 1W5  Date  Q^\\  I2,  ,  b n g i n o Q. C i r> Cj Columbia  my  I t i s thesis  w i t h o u t my  permission.  Department o f  thesis  by t h e h e a d o f  d e p a r t m e n t o r by h i s o r h e r r e p r e s e n t a t i v e s . understood  further  written  Abstract  This thesis determining  documents the i n v e s t i g a t i o n  solids  of three methods of  f l u x e s i n a c i r c u l a t i n g f l u i d i z e d bed (CFB).  flowmeter used the f o r c e of the r e c i r c u l a t i n g  particles  s t r i k i n g a pan  which spanned the diameter of the r e t u r n column to measure c i r c u l a t i o n rates.  A modified o r i f i c e , with a c o n i c a l  used the a d d i t i o n a l  pressure d i f f e r e n t i a l r e s u l t i n g  c o u n t e r - c u r r e n t l y to gas to determine s o l i d s the  v e l o c i t i e s of p a r t i c l e s  L - v a l v e to determine s o l i d s The r e s u l t s the  from s o l i d s  circulation  f l u x e s i n a CFB.  offer  flowing  The t h i r d method used  used.  the impact flowmeter and methods of  research i s required  The m o d i f i e d o r i f i c e ,  enough to sense s o l i d s  potential  of an  rates.  However, f u r t h e r  b e f o r e these methods can be c o n f i d e n t l y  meter may  section,  t r a v e l l i n g through the v e r t i c a l s e c t i o n  o b t a i n e d i n t h i s work show that  s t u d i e d , was not s e n s i t i v e  solids  entrance  method u t i l i z i n g L - v a l v e p a r t i c l e v e l o c i t i e s are v i a b l e  measuring s o l i d s  the  fluxes.  An impact  circulation.  as  However,  i f s t u d i e d with c o - c u r r e n t gas s o l i d s  flow.  -iii-  TABLE OF CONTENTS  Page ABSTRACT  i i  LIST OF TABLES  vi  LIST OF FIGURES  v i i  ACKNOWLEDGEMENT  1.  1.  xii  INTRODUCTION 1.1  Introduction  1  1.2  Previous  7  S t u d i e s and Methods  EXPERIMENTAL APPARATUS AND  PROCEDURES  2.1  Circulating  Bed System  2.2.1  F a s t F l u i d i z a t i o n Column and A i r Supply System  13  2.1.2  L-Valve  16  2.1.3  Cyclones  19  2.1.4  Return Column  24  2.1.5  Modified  24  2.2  Impact Flowmeter  28  2.2.1  Experimental  28  2.2.2  Meter L o c a t i o n  33  2.3  Modified  Orifice  35  2.3.1  Modified  O r i f i c e Equipment  39  2.3.2  Pressure  Measurement  41  2.3.3  Solids  B u t t e r f l y Valve  Set-Up  Feeding  13  41  -iv-  TABLE OF CONTENTS - CONTINUED  Page  3.  4.  5.  2.4  L-Valve  Calibration  2.5  Data A c q u i s i t i o n  2.6  P a r t i c l e Properties  42  and P r o c e s s i n g  44 45  RESULTS AND DISCUSSION  51  3.1  Introduction  51  3.2  General  51  3.2.1  Static Electricity  51  3.2.2  Solids  54  3.3  Impact Flowmeter R e s u l t s and D i s c u s s i o n  56  3.3.1  General  56  3.3.2  Impact Flowmeter R e s u l t s  64  3.3.3  Standard  74  3.3.4  Response of the Impact Flowmeter to B u t t e r f l y V a l v e C l o s u r e and Stoppage of S o l i d s C i r c u l a t i o n  88  3.4  M o d i f i e d O r i f i c e R e s u l t s and D i s c u s s i o n  89  3.5  L-Valve  94  3.6  B u t t e r f l y Valve  101  3.6.1  Introduction  101  3.6.2  B u t t e r f l y Valve Operating  3.6.3  E f f e c t of B u t t e r f l y V a l v e C l o s u r e  CONCLUSION  RECOMMENDATIONS  Observations  Circulation  Observations  Deviation  C a l i b r a t i o n R e s u l t s and D i s c u s s i o n  Difficulties  101 102  107  111  NOMENCLATURE  113  REFERENCES  115  -V-  TABLE OF CONTENTS - CONTINUED  Page APPENDIX A:  Computer  Programs  119  APPENDIX B:  Sieve A n a l y s e s and C a l c u l a t i o n of the average p a r t i c l e diameters  141  APPENDIX C:  Minimum F l u i d i z a t i o n , C a l c u l a t e d and E x p e r i m e n t a l and C a l c u l a t i o n of Archemedies Numbers and T e r m i n a l V e l o c i t i e s  144  APPENDIX D:  Dashpot O i l S p e c i f i c a t i o n s  149  APPENDIX E:  Data C o n v e r s i o n Formulae  151  APPENDIX F:  Impact Flowmeter Raw Data  154  APPENDIX G:  P a r t i c l e V e l o c i t y Raw Data  165  APPENDIX H:  T h e o r e t i c a l Model  173  APPENDIX I :  Operating Instructions  179  -vi-  LIST OF TABLES  Page T a b l e 2.1  Particle  Properties  46  -vii-  LIST OF FIGURES  Page F i g u r e 1.1  A conventional  circulating  f l u i d i z e d bed  4  F i g u r e 1.2  City College's c i r c u l a t i n g ( Y e r u s h a l m i e t a l . , 1978)  bed f a c i l t y  8  F i g u r e 1.3  U.B.C.'s c o n c e n t r i c c i r c u l a t i n g (Fusey e t a l . , 1985)  F i g u r e 2.1  The c i r c u l a t i n g  bed equipment  14  F i g u r e 2.2  The L - V a l v e . Numbers r e f e r to a e r a t i o n t a p s . A l l dimensions shown are i n mm •  17  F i g u r e 2.3  Primary c y c l o n e . A l l dimensions shown a r e i n mm.  21  F i g u r e 2.4  Secondary c y c l o n e . A l l dimensions shown a r e i n mm.  22  F i g u r e 2.5  T e r t i a r y c y c l o n e s and hopper. A l l dimensions shown a r c i n mm*  23  F i g u r e 2.6  Modified b u t t e r f l y valve. A l l dimensions shown are i n mm.  26  F i g u r e 2.7  Schematic of the p r e s s u r e measurement and r e c o r d i n g apparatus  27  F i g u r e 2.8  Impact flowmeter column s e c t i o n . A l l dimensions shown are In mm.  29  F i g u r e 2.9  Impact  30  F i g u r e 2.10  BLH l o a d beam. A l l dimensions shown are i n mm.  F i g u r e 2.11  Schematic of the l o a d beam s i g n a l and r e c o r d i n g apparatus  F i g u r e 2.12  B a f f l e / s c r e e n assembly used to r e d i s t r i b u t e s o l i d s separated by primary c y c l o n e . A l l dimensions shown are In mm.  36  F i g u r e 2.13  M o d i f i e d o r i f i c e meter A l l dimensions shown are i n mm.  37  F i g u r e 2.14  M o d i f i e d o r i f i c e meter a p p a r a t u s . A l l dimensions shown a r e i n mm.  40  F i g u r e 2.15  Particle velocity  43  bed  flowmeter  9  32  conditioning  measurement p o s i t i o n s  34  -viii-  LIST OF FIGURES - CONTINUED  Page F i g u r e 2.16  Photograph of the alumina p a r t i c l e s a t 400X magnification  47  F i g u r e 2.17  Photograph of an alumina p a r t i c l e a t 2000X magnification  48  F i g u r e 2.18  Photograph of a sand p a r t i c l e a t 200X magnification  49  F i g u r e 2.19  Photograph of a sand p a r t i c l e at 2000X magnification  50  F i g u r e 3.1  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on o s c i l l a t i o n of the 30° pan w i t h sand, U = 0.024 m/s, Uf = 5.0 m/s.  57  Photographs of the o s c i l l a t i n g impact flowmeter 60° pan w i t h sand, U = 0.024 m/s, Uf = 6.0 m/s, G = 25 kg/m s, based on the f a s t bed cross-sectional area.  59  Photograph of s o l i d s f l o w p a t t e r n e x i t i n g the primary c y c l o n e , U = 0.024 m/s, Uf = 60 m/s, G = 25 kg/m s, based on the f a s t bed cross-sectional area.  62  End view photograph showing sand s t r i k i n g the 60° pan, U = 0.024 m/s, Uf = 6.0 m/s, G = 25 kg/m s, based on the f a s t bed cross-sectional area.  62  I n f l u e n c e of s o l i d s f l u x , measured by a c c u m u l a t i o n on the b u t t e r f l y v a l v e and based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on e f f e c t i v e f o r c e f o r the 30° pan w i t h alumina, U = 0.014 m/s, Uf = 3.0 to 5.3 m/s.  65  I n f l u e n c e s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on e f f e c t i v e f o r c e f o r the 45° pan w i t h alumina, U = 0.014 m/s, Uf = 3.2 to 3.8 m/s.  66  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on e f f e c t i v e f o r c e f o r the 60° pan w i t h alumina, U = 0.014 m/s, Uf = 3.0 to 4.4 m/s.  67  s  F i g u r e 3.2  s  2  s  F i g u r e 3.3  g  2  s  F i g u r e 3.4  s  2  s  F i g u r e 3.5  s  F i g u r e 3.6  s  F i g u r e 3.7  s  -ix-  LIST OF FIGURES - CONTINUED  Page F i g u r e 3.8  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on e f f e c t i v e f o r c e f o r the 30° pan with sand, U = 0.024 m/s, Uf = 3.5 to 5.0 m/s.  68  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed cross-sectional a r e a , on e f f e c t i v e f o r c e f o r the 45° pan with sand, U = 0.024 m/s, Uf = 3.0 t o 6.6 m/s.  69  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on e f f e c t i v e f o r c e f o r the 60° pan with sand, U = 0.024 m/s, Uf = 4.7 to 5.5 m/s.  70  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan w i t h alumina, U = 0.014 m/s, Uf = 3.0 to 5.3 m/s.  75  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 45° pan w i t h alumina, U = 0.014 m/s, Uf = 3.2 t o 3.8 m/s.  76  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan w i t h alumina, U = 0.014 m/s, Uf = 3.0 to 4.4 m/s.  77  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan w i t h sand, U = 0.024 m/s, Uf = 3.5 t o 5.0 m/s.  78  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 45° pan w i t h sand, U = 0.024 m/s, Uf = 3.0 to 6.6 m/s.  79  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan w i t h alumina, U = 0.024 m/s, Uf = 4.7 to 5.5 m/s.  80  s  F i g u r e 3.9  s  F i g u r e 3.10  s  F i g u r e 3.11  s  F i g u r e 3.12  s  F i g u r e 3.13  s  F i g u r e 3.14  s  F i g u r e 3.15  s  F i g u r e 3.16  s  -x-  LIST OF FIGURES - CONTINUED  Page F i g u r e 3.17  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan with alumina, U = 0.014 m/s, U = 3.0 to 5.3 m/s.  81  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 45° pan with alumina, U = 0.014 m/s, U = 3.2 to 3.8 m/s.  82  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan with alumina, U = 0.014 m/s, U = 3.0 to 4.4 m/s.  83  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan with sand, U = 0.024 m/s, U = 3.5 to 5.0 m/s.  84  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the ' 45° pan with sand, U = 0.024 m/s, Uf = 3.0 to 6.6 m/s.  85  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan with sand, U = 0.024 m/s, Uf = 4.7 to 5.5 m/s.  86  E f f e c t of s o l i d s f l u x on m o d i f i e d o r i f i c e p r e s s u r e differential. A) Alumina f e d by f u n n e l , G = 25 kg/m s based on the o r i f i c e tube c r o s s s e c t i o n a l a r e a , U = 0.014 m/s. B) Sand f e d by secondary c y c l o n e , G = 22 kg/m s based on the o r i f i c e tube c r o s s - s e c t i o n a l a r e a , U = 0.024 m/s.  90  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on average p a r t i c l e v e l o c i t y measured a t d i f f e r e n t c i r c u m f e r e n t i a l positions for alumina, U = 0.014 m/s, Uf = 2.8 to 4.8 m/s.  95  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on average p a r t i c l e v e l o c i t y measured at d i f f e r e n t c i r c u m f e r e n t i a l positions f o r sand, U = 0.024 m/s, U = 3.0 to 6.0 m/s.  96  s  f  F i g u r e 3.18  s  f  F i g u r e 3.19  s  f  F i g u r e 3.20  s  f  F i g u r e 3.21  s  F i g u r e 3.22  s  F i g u r e 3.23  2  s  Q  2  s  Q  F i g u r e 3.24  s  F i g u r e 3.25  s  Q  -xi-  LIST OF FIGURES - CONTINUED  Page F i g u r e 3.26  E f f e c t of s o l i d s f l u x , based on f a s t bed c r o s s - s e c t i o n a l a r e a , on average p a r t i c l e v e l o c i t y f o r alumina, U = 0.014 m/s, Uf = 2.8 t o 4.8 m/s.  97  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on average p a r t i c l e v e l o c i t y f o r sand, U = 0.024 m/s, Uf = 3.0 to 6.0 m/s.  98  s  F i g u r e 3.27  s  F i g u r e 3.28  P r e s s u r e drop a c r o s s the b u t t e r f l y v a l v e versus time f o r three s u c c e s s i v e c i r c u l a t i o n r a t e measurements.  103  -xii-  Acknowledgement  I would l i k e  to express my  g r a t i t u d e to the f o l l o w i n g  individuals:  Dr. J.R.  Grace f o r h i s guidance,  the course  of t h i s  support  o p e r a t i o n of the CFB  Soszynski  IBM  computer and  XT  suggestions  during  study.  C l i v e B r e r e t o n f o r h i s i n s t r u c t i o n and  Robert  and  a s s i s t a n c e i n the  unit.  f o r h i s demonstration  i n the o p e r a t i o n of  the  the Tecmar Programmable d a t a l o g g i n g board  and  f o r the use of h i s data l o g g i n g program.  Dr. B. Bowen f o r the use of h i s p l o t t i n g  Frank L a y t n e r  I would a l s o l i k e  subroutines.  f o r h i s a s s i s t a n c e i n drawing the  to thank the s t a f f of the Chemical  figures.  E n g i n e e r i n g Stores  Workshops f o r t h e i r i n v a l u a b l e a s s i s t a n c e i n the d e s i g n , a c q u i s i t i o n c o n s t r u c t i o n of my  work and  and  equipment.  F i n a l l y , I would l i k e my  and  endured my  to thank a l l the o t h e r s who  presence  these past  years.  have a s s i s t e d me  in  -1-  1.1  Fluidized of  contacting  bed  beds c o n t i n u e a fluid,  Introduction  to be used i n i n d u s t r y as an e f f e c t i v e  u s u a l l y a gas, with  u n i t s , g e n e r a l l y operated  particulate solids.  i n the b u b b l i n g  or t u r b u l e n t  means  Fluidized  fluidization  regimes, have s u c c e s s f u l l y performed as: -  roasters  - catalytic - chemical  cracking/regeneration  units  r e a c t o r s f o r the p r o d u c t i o n  anhydride and other organo-chemical  products i n v o l v i n g h i g h l y  phthalic  exothermic  reactions  - combustors f o r c o a l , biomass, - gasifiers  of a c r y l o n i t r i l e ,  refuse  f o r c o a l and biomass  - heat exchangers and constant  temperature baths  - driers This  incomplete l i s t  of proven a p p l i c a t i o n s continues  to grow with the  e v e r - i n c r e a s i n g u n d e r s t a n d i n g and knowledge of f l u i d i z e d Some of the advantages of f l u i d i z e d  bed b e h a v i o u r .  beds over a l t e r n a t e  methods, such as r o t a r y k i l n s and packed moving beds, a r e : 1984;  contacting (Cohen et a l . ,  F i t z g e r a l d et a l . , 1984; Grace and Matsen, 1980; Sneyd, 1984) - compact  design  - nearly isothermal - simple beds  bed c o n d i t i o n s  g a s / s o l i d s i n t r o d u c t i o n and removal r e l a t i v e  .  - high g a s / s o l i d s heat and mass t r a n s f e r r a t e s - good s o l i d s mixing w i t h i n  the bed  to packed  -2-  - e f f i c i e n t heat a d d i t i o n and  removal  - improved combustor performance r e s u l t i n g a)  direct  removal and  b)  h i g h heat t r a n s f e r c o e f f i c i e n t s boiler  from:  r e d u c t i o n of atmospheric p o l l u t a n t s resulting  i n compact  designs  However, f l u i d i z e d beds have s e v e r a l disadvantages as w e l l : - increased p a r t i c l e  a t t r i t i o n and  elutriation relative  to packed  beds - gas  short c i r c u i t i n g of the s o l i d s when o p e r a t i n g  bubbling  i n the  regime  - h i g h e r o s i o n r a t e s of the bed  v e s s e l and  heat  exchange  surfaces - non-uniform s o l i d s - gas  time  backmixing  - difficulties To overcome these fluidized  residence  i n scaling-up  problems and  equipment  to b e t t e r understand  beds have been the s u b j e c t of c o n s i d e r a b l e  academic r e s e a r c h .  T h i s r e s e a r c h has  concentrated  b a s i c understanding  of f l u i d i z e d bed  behaviour and  e m p i r i c a l and scale-up  semi-empirical  design  particulate,  bubbling  and  have seen i n c r e a s e d  and  industrial  and  on the achievement of a the development of  c o r r e l a t i o n s , thus e n a b l i n g d e s i g n  fast  of f l u i d i z e d beds focussed  s l u g g i n g f l u i d i z a t i o n regimes. interest  regimes, both f o r p r a c t i c a l The  behaviour,  and  of u n i t s to be more r e l i a b l e .  U n t i l r e c e n t l y , the study  years  their  i n the t u r b u l e n t and  a p p l i c a t i o n s and  on  the  However, recent fast  i n fundamental  fluidization research.  f l u i d i z a t i o n regime, l y i n g between the t u r b u l e n t  pneumatic t r a n s p o r t regimes, i s c h a r a c t e r i z e d by a s o l i d s  fluidization suspension  of  -3-  voidage 0.8  to 0.995 which l a c k s a d i s c e r n i b l e bed  s u b s t a n t i a l net 200  2  kg/m s.  upflow of s o l i d s w i t h f l u x e s of the order  E x a m i n a t i o n of the  t r a v e l upward w i t h the gas, up  and  down In co- and  flow r e v e a l s  counter-current  flow  f a s t bed  an adjacent section. cyclones i n the  column i s u s u a l l y b u i l t  Entrained and  s o l i d s c a r r i e d out  c o l l e c t e d i n the  relative  Previous  vessel.  as p a r t of a c l o s e d  of the f a s t bed  loop  are  Yerushalmi et a l . , 1976;  Engstrom, 1980;  Yerushalmi and  gas  throughput  -  gas  backmixing  - intimate - ability - high  gas/solids  contacting  to handle cohesive  slip  1.1,  solids  velocities  enhanced g a s - t o - s o l i d s heat and  Jones,  fluidized  simple s o l i d s i n t r o d u c t i o n  little  separated  by  has  been  1983;  Cankurt, 1978), have  (reduced c r o s s - s e c t i o n a l a r e a )  - higher  upflow  (CFB).  s t u d i e s , (Cohen et a l . , 1984;  - compact d e s i g n  with  A b u t t e r f l y valve  as w e l l as a d d i t i o n a l advantages In terms o f :  -  loop,  i s f r e q u e n t l y used to determine  shown t h a t CFB's o f f e r most of the b e n e f i t s of other  -  gas,  T h i s arrangement, shown i n F i g u r e  a C i r c u l a t i n g F l u i d i z e d Bed  contactors  of p a r t i c l e s move  to the  s o l i d s return standpipe.  s o l i d s r e t u r n s e c t i o n of the  Roeck, 1982;  of 5 to  column to r e t u r n the p a r t i c l e s to the bottom of the  solids circulation rates. called  There i s a  that i n d i v i d u a l p a r t i c l e s  w h i l e " c l u s t e r s " or " s t r a n d s "  p r i n c i p a l l y near the w a l l of the c o n t a i n i n g The  surface.  mass t r a n s f e r  bed  -4-  CYCLONES  RETURN COLUMN UPFLOW COLUMN  BUBBLING BED  i—GAS  INLET  L- OR J-VALVE  GAS  Figure  1.1  INLET  A conventional  circulating  f l u i d i z e d bed  -5-  - improved  combustor performance  resulting  from;  a)  flexibility  i n fuel material  b)  controlled  c)  enhanced s u l p h u r c a p t u r e  d)  improved  e)  fewer number of f e e d p o i n t s r e q u i r e d  f)  reduced N0  turndown and load  combustion  X  following  efficiency  emission l e v e l s  However, CFB's have been shown to s u f f e r the disadvantages o f : al.,  1984;  Yerushalmi et a l . ,  et  1976)  - l i m i t a t i o n s on p a r t i c l e  size  - g r e a t e r heat t r a n s f e r s u r f a c e - difficult  (Cohen  gas/solids  requirements  separation  - scale-up u n c e r t a i n t i e s - accelerated Interest  equipment  erosion  i n CFB's has r e s u l t e d  i n d u s t r i a l and academic  communities.  i n e x t e n s i v e r e s e a c h i n both the T h i s r e s e a r c h has been d i r e c t e d  towards  a fundamental  u n d e r s t a n d i n g of the behaviour and dynamics of  systems  to be a p p l i e d  i n the d e s i g n and development  C u r r e n t areas of i n t e r e s t  CFB  of these u n i t s .  i n c l u d e the study o f :  - g a s - t o - p a r t i c l e heat and mass t r a n s f e r r a t e s and mechanisms - bed heat a d d i t i o n and - bed  removal  hydrodynamics  - e r o s i o n of CFB's and  their auxiliary  - p a r t i c l e a t t r i t i o n and - CFB load  equipment  elutriation  o p e r a t i n g c h a r a c t e r i s t i c s , e.g. s o l i d s holdup, following  turndown,  -6-  - the a p p l i c a b i l i t y of CFB's as chemical - combustion and g a s i f i c a t i o n To study these phenomena variables  reactors  processes  I t Is necessary to measure such fundamental  as: -  local solids  - solids -  density  throughput or f l u x  gas and s o l i d s v e l o c i t i e s and flow p a t t e r n s  - gas c o m p o s i t i o n as a f u n c t i o n of -  chemical c o n v e r s i o n of gaseous and s o l i d  - heat and mass t r a n s f e r -  position reactants  coefficients  combustion e f f i c i e n c i e s  - temperature - pollutant This project  profiles  emissions  addressed  the problem of s o l i d s  f l u x measurement, an  important parameter when s t u d y i n g any aspect of a CFB's o p e r a t i o n . r e s e a r c h and i n d u s t r i a l a p p l i c a t i o n s method of measuring s o l i d s  of a CFB, an a c c u r a t e ,  c i r c u l a t i o n rate i s desired.  would be n o n - i n t e r f e r i n g and s u i t a b l e high pressure  Ideally  f o r h i g h temperature and  the method possibly  aims of t h i s study were:  To develop one or more flowmeters to c o n t i n u o u s l y measure solid  2)  continuous  operation.  The p a r t i c u l a r 1)  In both  c i r c u l a t i o n r a t e s i n CFB's.  To t e s t  the flowmeter(s) at d i f f e r e n t  conditons, i . e d i f f e r e n t rates.  solids  CFB o p e r a t i n g  c i r c u l a t i o n and gas flow  -7-  3)  To  study the  effect  of  flowmeter geometry on  solids  c i r c u l a t i o n r a t e measurement. 4)  To  determine the  located 5)  To  i n the  investigate  effect  To  study the  velocity Two  and  c l o s u r e of  r e t u r n l o o p , on  solids  the  the  change i n s o l i d s 6)  of  response of  f e e d r a t e to  relationship solids  the  investigated:  recirculating  solids  An  i n the  entrance s e c t i o n  drop r e s u l t i n g  presence of  upwards moving gas  1.2  the  particle  f o r c e of  r e t u r n column; an  flowing  the  the  orifice  additional  pressure  counter-currently  stream.  P r e v i o u s S t u d i e s and  to  L-valve  c i r c u l a t i o n r a t e s were  utilized  solids  P r e v i o u s methods of measuring CFB presented problems due  a  bed.  impact flowmeter used the  m o d i f i e d with a c o n i c a l  through an  fast  c i r c u l a t i o n to  flux.  s t r i k i n g a pan  from the  valve,  flux.  solids  between the  d i s t i n c t methods of measuring s o l i d s  developed and  a butterfly  nature of  solids  Methods c i r c u l a t i o n r a t e s have  t h e i r o p e r a t i o n and  restricted  applicability. One  method used to measure s o l i d s  c i r c u l a t i o n loop and  observing  d e p l e t i o n below, the  b l o c k a g e , as  located to  i n the  stop the  solids  solids  et a l . , 1980).  the  flux  involved blocking  accumulation of a f u n c t i o n of  r e t u r n column of  the  c i r c u l a t i o n , F i g u r e 1.2  time.  above,  solids or  A butterfly  c i r c u l a t i o n l o o p , has  valve,  been used  (Yerushalmi et a l . , 1978;  In another study, a s l i d e v a l v e was  c i r c u l a t i o n , F i g u r e 1.3  solids  the  (Fusey et a l . , 1985).  used to stop  Bierl  solids  In both these methods,  c i r c u l a t i o n r a t e s were estimated by m o n i t o r i n g the  change i n p r e s s u r e drop,  -8-  CYCLONES  BUTTERFLYVALVE  Y UPFLOW COLUMN  EXPANDED VIEW  V .RETURN COLUMN  J-VALVE  Figure  1.2  City College's c i r c u l a t i n g 1978)  bed  facility  (Yerushalmi et a l . ,  -9-  F i g u r e 1.3  U.B.C.'s c o n c e n t r i c  circulating  bed  (Fusey et a l . ,  1985)  -10-  across  the v a l v e and  the accumulating  constructed  to be permeable to gas  to continue  to flow s l o w l y up  c i r c u l a t i o n was  blocked.  The  but  s o l i d s , with  time.  The  impermeable to s o l i d s , allowed  through the standpipe  while  the  upwards f l o w i n g gas maintained  on the v a l v e i n a f l u i d i z e d s t a t e , thus e n s u r i n g  distribution  on the v a l v e and  The basic  use  enabling s o l i d s drop a c r o s s  might s i g n i f i c a n t l y a f f e c t solids  A porous b u t t e r f l y  solids  c i r c u l a t i o n r a t e s has  the p r e s s u r e  or s l i d e v a l v e may  r a t e may  The  affect  unit  and  Dumping of  the  the CFB  to m a i n t a i n  method does not p r o v i d e a continuous  unit. in a measure  c i r c u l a t i o n rates involved  the movement of i d e n t i f i a b l e p a r t i c l e s  assuming uniform to the s o l i d s  problem may used.  through a  solids velocity  the s o l i d s  returned  to  ( G o l d b l a t t , 1985). i n the v a l v e and  a s s i g n i n g a bulk  f l o w i n g through the v a l v e , the s o l i d s  be e s t i m a t e d .  the L - v a l v e ,  passing  non-mechanical L- or J - v a l v e or loop s e a l as they  However, i f a v e l o c i t y  assumed bulk d e n s i t y i s not  being  of the CFB  be very d i f f i c u l t  the base of the upflow s e c t i o n of the CFB  density  four  circulation rates.  transparent  By  balance  of the measurement may  A second method used to determine s o l i d s observing  solids  solids.  the o p e r a t i o n of the equipment.  at the end  h i g h temperature r e a c t o r . of  even  C l o s i n g of the v a l v e c r e a t e s an a d d i t i o n a l p r e s s u r e  drop i n the system which p e r t u r b s  accumulated  solids  to be c a l c u l a t e d from  the v a l v e and  of a v a l v e to determine s o l i d s  limitations:  flux  gas  solids the  accumulating  the r a t e of change of p r e s s u r e  valves,  circulation  profile exists,  or  the  r e p r e s e n t a t i v e of the a c t u a l bulk d e n s i t y i n  c i r c u l a t i o n r a t e may  be overcome by c a l i b r a t i n g  be p o o r l y e s t i m a t e d .  This  the v a l v e f o r the p a r t i c u l a r  C a l i b r a t i o n would i n v o l v e measuring the s o l i d s , e.g.  solid  via a  -11-  butterfly the  v a l v e , and  relating  i t to the c o r r e s p o n d i n g s o l i d s v e l o c i t y i n  valve. To use these methods, t r a c e r p a r t i c l e s must be observed as they move  through the L- or J - v a l v e or loop s e a l . working w i t h ambient  temperature,  T h i s i s e a s i l y accomplished when  l a b o r a t o r y s c a l e CFB's, s i n c e such  may  be c o n s t r u c t e d from t r a n s p a r e n t m a t e r i a l s .  not  be s u i t a b l e f o r h i g h temperature  c o n s t r u c t i o n requirements and the  v a l v e may  and/or  the need  be i n c o n f l i c t .  units  However, t h i s approach  may  l a r g e CFB's, s i n c e m a t e r i a l s of  to observe s o l i d s movement through  Furthermore,  i t would be d i f f i c u l t  to  i n c o r p o r a t e t h i s flow measurement technique i n t o a system where automatic measurement of s o l i d s  c i r c u l a t i o n rates i s required.  A t h i r d method, which has not yet been a p p l i e d measurement but may  offer  withdrawal of f l u i d  and  the  promise, i s i s o k i n e t i c  solids  l o c a l stream v e l o c i t i e s .  to s o l i d s  sampling,  flux  involving  from a f l o w i n g stream at v e l o c i t i e s equal to T h i s technique minimizes  the e f f e c t  of the  sampling procedure on the stream flow behaviour and p r o v i d e s a sample more r e p r e s e n t a t i v e of the f l o w i n g stream. take gas and gas and loadings  solids  solids  samples  I s o k i n e t i c sampling has been used to  from spouted and f l u i d i z e d beds to determine  c o n v e r s i o n s , flow p a t t e r n s and v e l o c i t i e s , and  (Base, 1976;  van B r e u g e l , 1969/70).  s u c c e s s f u l l y used i n s i t u a t i o n s  I s o k i n e t i c probes have been  involving co-current gas/solids  these c a s e s , a hot wire anemometer has o f t e n been employed fluid  stream v e l o c i t i e s used  sample a dense g a s - s o l i d s  stream.  a v o i d p l u g g i n g of the probes by  flow.  In  to measure the  i n d e t e r m i n i n g the sampling r a t e s .  work, (van B r e u g e l , 1969/70), has shown that i s o k i n e t i c to  solids  Previous  probes may  be used  However, c a u t i o n must be e x e r c i s e d  solids.  to  -12-  By  assuming a u n i f o r m s o l i d s  solids  r e t u r n column, the  single  probe and  with p o s i t i o n  d i s t r i b u t i o n and  s o l i d s c i r c u l a t i o n r a t e can  sampling p o i n t .  However, i f the  and/or time, i t would be  arise  solids  the  broad p a r t i c l e s i z e d i s t r i b u t i o n  flow c o u n t e r - c u r r e n t l y at d i f f e r e n t  m i c r o n to m i l l i m e t e r sampling  rate.  s i z e , may  lead  solids  solids  i n d e t e r m i n i n g the  and  be  n e c e s s a r y to use  sampling p o i n t s and/or probes to measure the F u r t h e r problems may  velocity  flux  profile in  calculated flowrate a number  the  using varies  of  accurately.  sampling r a t e , velocities.  s i n c e the In  i n CFB's, t y p i c a l l y v a r y i n g  gas  addition, from  to c o m p l i c a t i o n s i n d e t e r m i n i n g  the  a  -13-  2.0  E x p e r i m e n t a l Apparatus and  2.1 The  CFB  unit  c i r c u l a t i n g bed bed  column and  Circulating  system c o n s i s t e d of a 0.330 m ID  storage v e s s e l .  entered  bottom of  f l o w i n g gas. f a s t bed  the  column.  Solids,  f a s t bed  solids  two  t e r t i a r y c y c l o n e s which c o u l d be  s t a n d p i p e , w h i l e the  f a s t bed,  bottom of  The  the  thus c l o s i n g  2.1.1  was  the  mm,  shorter flanged  3.18  mm  m.  introduction  at  the  and  bottom of  the  distribution.  upward of  the  were separated  a secondary c y c l o n e  of  the  from and  series.  return  solids  Particles L-valve  to  A i r Supply System m ID  transparent  The  column, of  acrylic  h e i g h t 9.14  A 0.156  f a s t bed The  m,  was  s e c t i o n s , v a r y i n g i n l e n g t h from  S e a l s between s e c t i o n s were provided by  diameter butadiene 0 - r i n g s .  distributor  acting  p e r m i t t e d v i s u a l o b s e r v a t i o n to be made  assembled from a s e r i e s to 1.37  fast  loop.  Column and  measurements.  of  bed  out  exhausted to atmosphere.  concurrently with physical  m  fast  b u b b l i n g bed  column, c o n s t r u c t e d of 0.152  t u b i n g of w a l l t h i c k n e s s 6.4  0.46  the  circulation  ID  the  r e t u r n v e s s e l downward through the  Fast F l u i d i z a t i o n  f a s t bed  s o l i d s upward and  arranged i n p a r a l l e l or  to the  c a r r i e r gas  l a t t e r also  were e n t r a i n e d by  a primary c y c l o n e , f o l l o w e d by  Separated s o l i d s were r e t u r n e d  m  a non-mechanical L - v a l v e ,  f l u x of  exiting  c a r r i e r gas  the  by  column and  the  The  p a r a l l e l columns, a 0.152  fed  i n a net  Entrained by  two  r e t u r n s t a n d p l p e , w i t h the  This resulted  flowed from the  System  used i n t h i s study i s shown i n F i g u r e 2.1.  as a s o l i d s the  Bed  Procedures  m diameter  0.191  m  ID,  multi-orifice  column p r o v i d e d primary a i r  distributor,  designed to have 19%  free  -14-  SECONDARY CYCLONE PRIMARY CYCLONE VIEWING PORT  GAS EXHAUST TERTIARY CYCLONES SOLIDS HOPPER  IMPACT FLOWMETER BUTTERFLY VALVE  UPFLOW COLUMN  DISTRIBUTOR PLATE AERATION  SECONDARY AIR PORTS  DISTRIBUTOR PLATE PRIMARY AIR INLET  F i g u r e 2.1  L-VALVE  NEOPRENE COLLAR  The c i r c u l a t i n g  bed equipment  -15-  area, 12.7  consisted mm  of 200  thick Dural  mesh s t a i n l e s s s t e e l s c r e e n  Aluminum d i s t r i b u t o r p l a t e s .  backflow of s o l i d s i n t o the windbox and  piping.  r e s p e c t i v e l y , on a 12.7  p l a c e by  the windbox which was  S o l i d s entered side i n l e t was left  mm  square p i t c h .  bolted  c l o s e d w i t h a 12.7  mm  top of the  f a s t bed  kPag compressor or a 0.15  The  compressor d i d not  f l u i d i z a t i o n regimes. providing  m ID  3  was  Gas  m ID  held  in  circular  The  top of the  and  entrained  m /s,  the bed the bed The  using  vessel solids m  3  e i t h e r a 0.03  m /s,  50 kPag S u t o r b u i l t blower, model  i n the  capacity fast  to p r o v i d e  i n the p a r t i c u l a t e , b u b b l i n g  blower, on  the other  v e l o c i t i e s up  to 8.0  Secondary a i r , c o u l d  gas  hand, was m/s,  a l s o be  or  7HV.  velocities  f l u i d i z a t i o n regime, but  was  turbulent  capable of  which was  p a r t i c u l a t e m a t e r i a l used i n t h i s  f l u i d i z a t i o n regime.  diameter  s i d e o u t l e t l o c a t e d 0.152  provided  have s u f f i c i e n t  s u p e r f i c i a l gas  f o r s u s t a i n i n g the  mm  d i s t r i b u t o r was  through a 0.152  thick blind flange.  200  u s e f u l for operating  7.9  lower  column.  Primary a i r to the  capable of m a i n t a i n i n g  prevented  upper and and  The  m above the d i s t r i b u t o r .  the upflow v e s s e l through a 0.102  below the  mm  screen  two  to the bottom of the upflow column.  the v e s s e l from the L - v a l v e  l o c a t e d 0.152  The The  d i s t r i b u t o r p l a t e s were d r i l l e d w i t h a l i g n e d 6.4 holes  sandwiched between  sufficient  study i n the  supplied  by  the  fast blower.  -16-  Compressor a i r f l o w was 25.4  mm  globe v a l v e .  metered by a rotameter  Blower a i r f l o w to the f a s t bed  w i t h an o r i f i c e meter c e n t r a l l y ID copper 0.08,  tube.  0.17,  and  l o c a t e d i n a 2.24  r e g u l a t e d with a  column was  m s t r a i g h t run of 76.2  Four o r i f i c e s , w i t h o r i f I c e - t o - t u b e diameter  0.41  and  0.67,  measured  were a v a i l a b l e f o r use  mm  r a t i o s of  i n the o r i f i c e meter.  O r i f i c e meter p r e s s u r e d i f f e r e n t i a l s were measured by a water manometer, w h i l e p r e s s u r e s upstream of the meter were measured w i t h a mercury manometer.  R e g u l a t i o n of the blower a i r f l o w was  gate v a l v e , downstream of the o r i f i c e meter, was adjustment.  A 76.2  provided fine The  globe v a l v e , t i e d  flow adjustment  f a s t bed  s t a r t i n g 0.152  column was  gas and  A 76.2  used  flow  equipped  solids  f o r coarse  the blower d i s c h a r g e .  w i t h w a l l p o r t s at 0.457 m  sampling  mm  i n upstream of the o r i f i c e meter,  by b l e e d i n g a i r from  m above the d i s t r i b u t o r .  c a p a c i t a n c e and and  mm  by two v a l v e s .  These p o r t s were used probes,  up to 6.4  mm  to  intervals, insert  i n diameter,  to take p r e s s u r e measurements along the l e n g t h of the column.  2.1.2  L-Valve  S o l i d s r e t u r n e d to the bottom of the f a s t bed non-mechanical L - v a l v e shown i n F i g u r e 2.2. a tall,  vertical  s e c t i o n of pipe connected  "L" c o n f i g u r a t i o n . S o l i d s movement through varying 1977).  through  the  L-valves generally consist  of  at 90° to a s h o r t e r p i p e , i n an the v a l v e was  a d j u s t e d by  the p o i n t and degree of a e r a t i o n of s o l i d s i n the v a l v e (Knowlton,  RETURN COLUMN  ure  2.2  The L - V a l v e . Numbers r e f e r to a e r a t i o n A l l dimensions shown are i n mm.  taps.  -18-  Th e L - v a l v e  used i n t h i s study had  l e n g t h 2.74  m and  l e g entered  the b u b b l i n g  windbox, F i g u r e bed, The  0.89  2.1.  m respectively. bed  of the  S o l i d s fed to the  h o r i z o n t a l l e g of the v a l v e was f a s t bed  sections  The  upper p o r t i o n of the  top of the L - v a l v e ,  Aeration  differential  of the L - v a l v e  base of the v e r t i c a l  connected to the  solids  and  expansion i n the was  provided  shown i n F i g u r e  using 2.2.  s e c t i o n of the L - v a l v e  m above the base of the v a l v e .  bubbling  inlet  section  the h o r i z o n t a l l e g .  any  combination  Eight  o f f s e t by  l e g of the v a l v e .  on a l t e r n a t e s i d e s of the v e r t i c a l  Four p o r t s  of  a e r a t i o n p o i n t s at spaced around  aligned  the  base i n l i n e w i t h the h o r i z o n t a l l e g , were used to a e r a t e  the  seventeenth a e r a t i o n port was  the  Along the base of the  s o l i d s i n the h o r i z o n t a l l e g .  l o c a t e d on  0.076 m above i t s base, d i r e c t l y o p p o s i t e  to lower  l o c a t e d every 0.30 the  f o u r p o r t s were used to a e r a t e  0.20  with  s o l i d s i n the  m above  leg.  the  45° w i t h r e s p e c t  s e c t i o n , s t a r t i n g 0.85  In the upper p o r t i o n of the v e r t i c a l  the  i n s e t s of f o u r at  lower set was  These p o r t s were used to a e r a t e  s e c t i o n of the v e r t i c a l  the  system.  were evenly  The  the h o r i z o n t a l l e g , w h i l e the upper set was  L-valve  the  the  compensated f o r  c i r c u m f e r e n c e of the v e r t i c a l s e c t i o n of the L - v a l v e 0.54  vertical  v e s s e l by a f l e x i b l e neoprene c o l l a r which p e r m i t t e d  seventeen a e r a t i o n p o r t s  m and  by  of  to the bottom of the upflow column.  to move i n d e p e n d e n t l y of each other  misalignment and  horizontal sections  r e t u r n v e s s e l from below through  flowed downward through the v a l v e  of the  v e r t i c a l and  the v e r t i c a l l e g of the the h o r i z o n t a l l e g .  m  solids  L-valve, The L-valve  Airflow  to  -19-  to each a e r a t i o n port was 6.4  mm  needle  measured by a rotameter  and  r e g u l a t e d with a  valve.  S o l i d s f l o w r a t e through i n j e c t i o n p o i n t s and smooth flow of f i n e  the L - v a l v e was  a d j u s t e d by v a r y i n g the a i r  a i r I n j e c t i o n r a t e s i n the L - v a l v e . s o l i d s , dp  < 100  um,  s o l i d s i n the h o r i z o n t a l l e n g t h of  the v a l v e were v i g o r o u s l y a e r a t e d , w h i l e s o l i d s aerated  To p r o v i d e a  i n the upper p o r t i o n of  vertical  l e g were thoroughly  to e l i m i n a t e b r i d g i n g .  r a t e was  a d j u s t e d by v a r y i n g the a e r a t i o n r a t e to the p o r t s i n the  p o r t i o n of the v e r t i c a l s e c t i o n of the L - v a l v e and horizontal leg.  Higher  Circulation  still  s o l i d s , dp > 100  a e r a t i o n p o r t s #6  c o n t r o l and  um,  by the p r e v i o u s l y mentioned p o r t s . #7,  F i g u r e 2.2,  S o l i d s e n t r a i n e d with  For  i n c y c l o n e s and  Gas  exiting  were used to  solids  l e a v i n g the f a s t  recirculated  the f a s t bed,  flowed  fluidization  to the s o l i d s through  a 0.102  m ID  c y c l o n e where the m a j o r i t y of the s o l i d s were  separated.  m 0D  A 0.127  plexiglass  o b s e r v a t i o n s , sampling  column; see F i g u r e 2.1.  m ID f l e x i b l e hose.  The  mm  standpipe. flexible  probe port  and measurements of the flow e x i t i n g  S o l i d s not  were c a r r i e d w i t h the exhaust gas 0.127  s e c t i o n with a 9.5  column  return  hose to the primary  fast  coarse  Cyclones  the gas  were r e c o v e r e d  permitted  the  adjust solids c i r c u l a t i o n r a t e s .  2.1.3  and  and  the  by i n c r e a s i n g the  flow of a i r to the h o r i z o n t a l l e g a e r a t i o n p o r t s , but c o n t r o l of c i r c u l a t i o n r a t e was  lower  the p o r t o p p o s i t e  c i r c u l a t i o n r a t e s were o b t a i n e d  the  separated by  to the secondary  the primary  c y c l o n e through  exhaust l e a v i n g the secondary  the  cyclone a  cyclone  flowed  -20-  through  a 0.102  exhausted The  m ID f l e x hose to the t e r t i a r y c y c l o n e s and was  then  to atmosphere. primary  c y c l o n e , F i g u r e 2.3,  seamless m i l d s t e e l p i p e , was  c o n s t r u c t e d from 0.203 m ID sch.  situated  on top of the s o l i d s  recirculation  column, F i g u r e 2.1.  T h i s c y c l o n e d i d not have a c o n i c a l  the separated  dropped d i r e c t l y from the c y l i n d r i c a l body of  solids  c y c l o n e to the f r e e b o a r d of the s o l i d s The  secondary  T h i s c y c l o n e was  c y c l o n e , F i g u r e 2.4,  by  a e r a t e d 63.5  mm  both  0.188  i n series  stainless  flow e x i t i n g  m ID Stairmand  or p a r a l l e l .  re-entrainment.  the secondary  t e r t i a r y cyclones. tertiary  solids  by a b l i n d operating  the  further  solids  separation.  s c h . 40 seamless m i l d  steel  mm  Solids  mild s t e e l plate.  to the r e t u r n column through  below the b u b b l i n g bed  m  t e r t i a r y cyclones,  were operated  individually  These c y c l o n e s were f a b r i c a t e d  or as  from 18 gauge  welds of the c y c l o n e s ground smooth to  A PVC  cyclone into  At low gas  an  surface.  type h i g h e f f i c i e n c y  s t e e l w i t h the i n s i d e  minimize s o l i d s  two  and  of the geometry shown i n F i g u r e 2.5,  a pair 304  two  c y c l o n e flowed  Instead,  ID f l e x i b l e hose e n t e r i n g the v e s s e l at a p o i n t 0.93  above the d i s t r i b u t o r The  provided  bottom formed from 6.4  the secondary  bottom.  vessel.  c o n s t r u c t e d from 0.203 m ID,  p i p e , w i t h the c o n i c a l separated  return  40  "Y"  shaped flow s p l i t t e r d i v i d e d  two  streams which flowed  flowrates, a single  c y c l o n e was  the  to the  used f o r  s e p a r a t i o n , w i t h the flow to the other c y c l o n e blocked o f f  flange.  Improved s o l i d s  s e p a r a t i o n was  the t e r t i a r y c y c l o n e s i n s e r i e s .  accomplished  For h i g h gas  by  throughputs,  the  c y c l o n e s were used i n p a r a l l e l , w i t h equal flow to each c y c l o n e .  Separated hopper and  s o l i d s were c o l l e c t e d periodically  in a conical  bottom 304  r e t u r n e d to the s o l i d s  stainless  i n v e n t o r y column.  steel  -21-  203  102  GAS GAS/SOLIDS  EXHAUST  INLET  o  CN  CN  MOUNTING FLANGE  O lO  CN  SOLIDS  Figure  2.3  Primary c y c l o n e .  EXHAUST  A l l dimensions shown are i n mm.  -22203  4  _>  -»J 127 | * -  GAS  EXHAUST  GAS/SOLIDS  Figure  2.4  Secondary c y c l o n e .  A l l dimensions shown are i n  mm.  Figure  2.5  T e r t i a r y c y c l o n e s and hopper.  A l l dimensions are i n  mm.  -24-  2.1.4 The acrylic  6.43  m tall  t u b i n g , 6.4  shorter flanged  r e t u r n column, c o n s t r u c t e d mm  w a l l t h i c k n e s s , was  s e c t i o n s , v a r y i n g f rom  0 - r i n g s , 0.40  m ID,  column served  two  3.18  mm  functions:  upflow column; i t served bed  height  operating,  secondary c y c l o n e  the  0.48  I t provided  at approximately  s o l i d s bed  covered  thereby  operation,  solids  valve.  distributor up  A i r entered  primary c y c l o n e The  of a p i e c e of 200  mesh s t a i n l e s s  solids  gas  and  the  solids  When the the  solids  return l i n e .  During  to p r o v i d e  free  by a 0.03  m /s,  and  3.2  mm  3  r e g u l a t e d by a 25.4  and  e x i t e d the  out with  the gas  standpipe  mm  The  s t e e l screen upper and  diameter h o l e s  by  flowing  exhausted from  d i s t r i b u t o r , with a f r e e area of 1.2%,  aluminum d i s t r i b u t o r p l a t e s .  pitch.  m.  to  the r e t u r n v e s s e l through a m u l t i - o r i f i c e  at the bottom of the v e s s e l and  mm  static  the r e t u r n port of  s u p p l i e d to the r e t u r n v e s s e l bed  primary c y c l o n e .  1.6  1.3  i n the r e t u r n column were f l u i d i z e d  a i r was  the column and  aligned  The  preventing  kPag compressor, metered by a rotameter and  globe  for solids  The  L-valve.  Fluidizing 207  Butadiene  s e a l s between s e c t i o n s .  maintained  solids return l i n e ,  rolled  m i n length.  inventory v e s s e l .  through the secondary c y c l o n e  movement to the  to 1.40  a return route  from bypassing the  of 0.343 m ID  assembled from a number of  diameter, p r o v i d e d  as a s o l i d s  i n the column was  equipment was  Return Column  was  composed  sandwiched between two  Dural  lower p l a t e s were d r i l l e d  r e s p e c t i v e l y , on a 12.7  the  mm  with  square  -25-  2.1.5 A modified the  as  opposed  butterfly  1.2%. leaf  the  valve.  downward, the  s o l i d s backflow  located outside  The l e v e r s moved t h e fully  plates  s o l i d s from f l o w i n g  permitted  gas  upflowing  gas m a i n t a i n e d the  Solids  to  pitch,  f l o w upward t h r o u g h the  two d i a m e t r i c a l l y diameters  screen.  were d r i l l e d  on t h e  of  plates,  of  to  each  the  rods of  vertically  closed.  When c l o s e d ,  downward t h r o u g h t h e  column  but  v a l v e and a c c u m u l a t e d s o l i d s .  accumulated s o l i d s i n a f l u i d i z e d  drop across  the  with  area  t h e v a l v e and a c c u m u l a t e d s o l i d s .  d r o p s , m e a s u r e d by a D i s a m o d e l 51D20 c a p a c i t a n c e  pressure  The  state.  a c c u m u l a t i o n r a t e s w e r e d e t e r m i n e d by m o n i t o r i n g t h e  change o f p r e s s u r e  rods  The v a l v e was  attached  range  fully  to  t h e movements o f  orifices  over the  circulation  g i v i n g a free  column,  open to h o r i z o n t a l l y opposed,  valve prevented  solids  so t h a t  steel the  column 2.53 m above  along t h e i r  through the  200 mesh s t a i n l e s s  by two l e v e r s ,  of  The p l a t e s  h o l e s on a 1 2 . 7 mm s q u a r e  was c o v e r e d w i t h  operated  attached  The g e a r s meshed t o g e t h e r  To p r e v e n t  return  The v a l v e was made f r o m  v a l v e l e a v e s were s y n c h r o n i z e d .  mm d i a m e t e r  Valve  l o c a t e d i n the  s e m i c i r c u l a r aluminum p l a t e s ends.  Butterfly  t o p r o v i d e one m e a s u r e  shown i n F i g u r e 2 . 6 .  w i t h geared  1.6  butterfly valve,  d i s t r i b u t o r , was u s e d  rates  Modified  rate of Pressure  tranducer  used  I n c o n j u n c t i o n w i t h a D i s a m o d e l 5 1 E 0 2 - 2 t u n i n g p l u g a n d m o d e l 51E01 reactance  converter  a digital  v o l t m e t e r , w h i l e permanent  Esterline,  and e x p r e s s e d  model S6015, c h a r t  as  equivalent voltages,  w e r e d i s p l a y e d on  r e c o r d s were o b t a i n e d u s i n g an  recorder.  The s e t - u p  is  shown i n F i g u r e 2 . 7 .  -26-  F i g u r e 2.6  Modified  butterfly valve.  A l l dimensions shown are i n  mm.  -27-  LOW PRESSURE SIGNAL  REACTANCE CONVERTER OSCILLATOR  HIGH PRESSURE SIGNAL TUNING PLUG  PRESSURE TRANSDUCER  CHART RECORDER  DIGITAL VOLTMETER  COMPUTER DATALOGGER  SHIELDED ELECTRICAL  CABLE  UNSHIELDED ELECTRICAL  Figure  2.7  CABLE  Schematic of the p r e s s u r e measurement and r e c o r d i n g apparatus.  -28-  2.2 The study was  Impact Flowmeter  s o l i d s f l o w measurement technique of primary i n t e r e s t the impact  flowmeter,  F i g u r e s 2.8  and  2.9.  in this  T h i s meter used  load beam to measure the f o r c e of the r e c i r c u l a t i n g s o l i d s f a l l i n g pan  a  onto  a  extending a c r o s s the s o l i d s r e t u r n column. The  p r i n c i p l e of u s i n g a load c e l l  s u c c e s s f u l l y demonstrated transfer  f o r f o r c e measurement  was  by Hosny (1983) i n h i s study of f o r c e s on heat  tubes i n b u b b l i n g f l u i d i z e d  beds.  Although  the magnitudes of  the  f o r c e s were c o n s i d e r a b l y g r e a t e r i n that work, the use of l o a d beams f o r dynamic f o r c e measurement i n f l u i d i z e d  systems was  shown to be f e a s i b l e  and  reliable. A commercially  a v a i l a b l e s e r i e s of s o l i d s flowmeters,  same p r i n c i p a l as the impact Canada. resulting  flowmeter,  are marketted  o p e r a t i n g on  by M i l l t r o n l c s  These meters measure the h o r i z o n t a l component of the from p a r t i c l e s s t r i k i n g  an i n c l i n e d  pan.  particle  s i z e s r a n g i n g from  S i n c e o n l y the  F l o w r a t e s as low as 0.5  f i n e powders to 13 mm  Inc.,  force  h o r i z o n t a l component of the f o r c e i s measured, the meters are not by s o l i d s a c c u m u l a t i o n on the pan.  the  affected  Tonne/hr f o r  can be measured.  However, i t i s n e c e s s a r y to c o n c e n t r a t e the s o l i d s upstream of the flowmeter  so that  they flow through a 51 mm  2.2.1 The  impact 2  flowmeter  10 to 100 kg/m s, based  was  ID p i p e .  E x p e r i m e n t a l Set-Up designed  on the f a s t bed  to measure s o l i d  f l u x e s ranging  column c r o s s - s e c t i o n a l a r e a . 2  S o l i d s Impacted on a pan w i t h a p r o j e c t e d area of 0.033 m , and 0.33  m l o n g ) , n e a r l y spanning  from  the diameter  (0.10 m wide  of the r e t u r n column.  The  pan  -29-  PRESSURIZED BOX RUBBER GASKET MOUNTING PLATESFLANGE  PLEXIGLASS WINDOW LEVER APPARATUS AIR PORT  ,WALL PORTS -LEVER ARM O  p  r PAN LOAD BEAM CABLE PRESSURE PORT  T FLANGE "RETURN COLUMN WALLS  273  343 -*  •*  F i g u r e 2.8  457  Impact flowmeter column s e c t i o n . are i n mm.  A l l dimensions shown  -30-  LOAD BEAM MOUNTING POST  BASE PLATE  LOAD BEAM BEARING BLOCKS  COUNTER-WEIGHT  BEARING SHAFTS  LEVER LOCKING NUTS SENSING SCREW  MOUNTING PLATE  F i g u r e 2.9  Impact flowmeter  -31-  was In the form o f an i n v e r t e d  "V", w i t h the angle of the s i d e s  exceeding  the angle of repose of the s o l i d s , i n order to prevent s o l i d s a c c u m u l a t i o n on  the pan.  investigated  Three pan a n g l e s , 3 0 ° , 4 5 ° , and 60° from the h o r i z o n t a l , were i n t h i s study.  The pan was attached  a t one end to a  pivoted  l e v e r arm which passed through the w a l l of the r e t u r n column, as shown i n Figure  2.8.  The p i v o t was l o c a t e d  outside  the column.  An  adjustable  weight, to counter balance the pan and l e v e r assembly, was attached end  of the l e v e r o p p o s i t e  attached  75 mm  the pan, F i g u r e  2.9.  An oil-damped  Figure  2.8 and 2.9, had a 2.54 mm p i s t o n c o n t a i n e d  c y l i n d e r which was f i l l e d s p e c i f i c a t i o n s are given A point Figure  2.9.  dashpot,  from the p i v o t of the l e v e r on the s i d e o p p o s i t e  was used to dampen r a p i d o s c i l l a t i o n s of the l e v e r system.  contact  with M o b i l in  bearing  within  to the  the pan,  The dashpot, a 3.15 mm  600 w gear o i l . The o i l  Appendix D. was used as the l e v e r p i v o t  T h i s d e s i g n of b e a r i n g  i n t h i s study,  was chosen because i t f i x e d the  l o c a t i o n o f the l e v e r , minimized f r i c t i o n and allowed the equipment to be orientated  i n any p l a n e .  The p i v o t s h a f t of the l e v e r , machined w i t h a  c o n i c a l c a v i t y i n each end, was h e l d between two hardened s t e e l f i x e d w i t h c o n i c a l ends, p r e s s i n g  i n t o the two c a v i t i e s .  On the s i d e of the l e v e r o p p o s i t e was l o c a t e d , F i g u r e  2.10.  threaded i n t o the sensing screw c o n t a c t e d  the pan, a 0.454 kg BLH load beam  A screw, machined w i t h a c o n i c a l end, was end of the l o a d beam.  the l e v e r assembly and provided  between the l e v e r and the load beam. 230  The c e n t r e  The c o n i c a l end of the a mechanical c o n n e c t i o n of the pan assembly was  mm from the p i v o t p o i n t , w h i l e the load beam c o n t a c t  from the p i v o t  point.  pins  Thus, the f o r c e f e l t  p o i n t was 51 mm  by the load beam was  a p p r o x i m a t e l y f o u r and one h a l f times the f o r c e exerted  on the pan.  -32-  DIRECTION OF MOVEMENT  +h 3  Et  SENSING END  PROTECTIVE COVER  O  MOUNTING POST  O  ELECTRICAL CABLE  F i g u r e 2.10  BLH load beam.  A l l dimensions shown are i n mm.  -33-  E x c i t i n g v o l t a g e and  s i g n a l c o n d i t i o n i n g f o r the load beam were provided  a B o f o r s , model B-2-F, t r a n s d u c e r a m p l i f i e r module. was  d i s p l a y e d on a d i g i t a l v o l t m e t e r .  EMI  UV  O s c i l l o g r a p h , model SE 6150  Figure To  Mk  The  amplifier  prevent  sheet metal  Permanent r e c o r d s were made u s i n g II.  The  solids  from escaping  box,  0.20  m deep by 0.25  from the r e t u r n column through o u t s i d e the column was m wide by 0.27  the box  through  flowed  horizontally  r e t u r n column.  The  r e g u l a t e d by a needle  The  valve.  from the box  flowmeter was  b u b b l i n g bed  the b u b b l i n g bed  The  vertical  Box  and HoO  pressure  box.  Meter L o c a t i o n  the primary  separated  by  c y c l o n e s o l i d s e x i t , F i g u r e 2.1.  the primary  c y c l o n e cascaded through  In  downward to  the upward  gas.  e l e v a t i o n of the impact  meter apparatus  minimize the e f f e c t s of non-uniform s o l i d s d i s t r i b u t i o n particle  at 5 to 10 mm  to the column.  s u r f a c e at near t e r m i n a l v e l o c i t i e s  flowing f l u i d i z a t i o n  and  l o c a t e d i n the s o l i d s r e t u r n column between the  s u r f a c e and  section, solids  the  between the box  maintained  a d j u s t e d by v a r y i n g the a i r f l o w r a t e to the  2.2.2  A i r fed to  metered u s i n g a rotameter  pressure d i f f e r e n t i a l  column, measured u s i n g a water manometer, was to ensure t h a t the a i r flow was  with  s o l i d s from i n t e r f e r i n g with  a i r flow was  The  in a  the port i n the column w a l l to the  flow of a i r prevented  l o a d beam b e a r i n g assembly.  enclosed  the  m l o n g , equipped  o b s e r v a t i o n of the equipment.  this  an  i n s t r u m e n t a t i o n i s shown i n  an a c r y l i c window to permit  The  voltage  2.11.  l e v e r p o r t , the l o a d beam apparatus  was  by  p r o j e c t i o n from the b u b b l i n g bed  s u r f a c e below.  was  chosen to  from above  and  Solids leaving  -34-  AMPLIFIER  rl  ta  LOAD BEAM  DIGITAL VOLTMETER  CHART RECORDER  COMPUTER DATALOGGER  SHIELDED ELECTRICAL UNSHIELDED  F i g u r e 2.11  CABLE  ELECTRICAL  CABLE  Schematic of the load beam s i g n a l c o n d i t i o n i n g and apparatus.  recording  -35-  the primary  c y c l o n e f o l l o w e d a h e l i c a l downward t r a j e c t o r y .  the primary  c y c l o n e ' s c e n t r i f u g a l f o r c e s , the p a r t i c l e s c o n c e n t r a t e d  the column w a l l , a l l o w i n g some to escape c o n t a c t w i t h through  the 6.4  mm  gas between the ends of the pan  p r o j e c t e d upwards from the b u b b l i n g bed reduce the net f o r c e a c t i n g on the pan. b u b b l i n g bed was  always operated  apparatus  A baffle, thus  was  2.8  T h i s was  was mm  an annular  into  sheet metal  the column from the  square  meter and  openings supported  baffle,  i n s e r t w i t h 45°  sides  wall.  d i r e c t l y above the  The  on two  baffle,  f u r t h e r promote  uniform  assembly c o n s i s t e d of a rigid  wire screens  with  openings a l i g n e d a t 45° w i t h r e s p e c t to each o t h e r ,  2.13.  2.3  orifice  The  inward,  a c r o s s the e n t i r e column  s o l i d s d i s t r i b u t i o n as shown i n F i g u r e 2.12.  The  the  surface.  used to dampen s o l i d s f l o w r a t e f l u c t u a t i o n s and  s c r e e n w i t h 1 mm  could  t h a t flow of  n e g l i g i b l e and  i n the core of column.  c r o s s - s e c t i o n upstream of the impact  Figure  Particles  a minor problem s i n c e the  was  m above the b u b b l i n g bed  A c o a r s e s c r e e n assembly, extending  square  the w a l l .  a t a flow low enough such  i n c r e a s i n g the flow of s o l i d s  which p r o j e c t e d 12.7  5 mm  and  falling  l o c a t e d a t the column w a l l , d e f l e c t e d the p a r t i c l e s  shown i n F i g u r e 2.12,  was  the pan by  flowmeter of secondary  Modified  Orifice  interest  i n t h i s study was  or v e n t u r i shown i n F i g u r e 2.13.  of  near  s u r f a c e by e r u p t i n g bubbles  p a r t i c l e s p r o j e c t e d upwards by b u r s t i n g bubbles impact  As a r e s u l t  the m o d i f i e d  T h i s meter, suggested  by  Reh  F i g u r e 2.12  B a f f l e / s c r e e n assembly used to r e d i s t r i b u t e s o l i d s s e p a r a t e d by primary c y c l o n e . A l l dimensions shown are i n mm.  -37-  DIRECTION  OF SOLIDS  FLOW  CONICAL  F i g u r e 2.13  Modified  o r i f i c e meter.  ENTRANCE  SECTION  A l l dimensions shown are i n mm.  -38-  (1984),  utilized  an o r i f i c e with a c o n i c a l entrance  pressure d i f f e r e n t i a l  related  assembly was  to study  designed  c o n i c a l entrance  to s o l i d s  s e c t i o n to develop  circulation rates.  The  s e c t i o n to measure the s o l i d s  effect  of o r i f i c e  orifice-to-tube  ratio,  to be s t u d i e d .  geometry, i . e . cone angle and  of u s i n g a c o n s t r i c t i o n  g a s / s o l i d s f l o w r a t e s was C a r l s o n ' s study, p l a t e was  i t was  insensitive  to the presence  and  solids  w i t h an o r i f i c e  flowrates.  of f i n e  flow.  the s o l i d s  not  affect  metering  The  rapid  flowrates resulted the s o l i d s  found  orifice  to  gas. both  solids  plate.  the  from i t s  to a c c e l e r a t e to  c o n s t r i c t i o n of an o r i f i c e  the p r e s s u r e drop a c r o s s the o r i f i c e  the  p l a t e d i d not  Thus the s o l i d s d i d The  ability  to use  flowmeter with a g r a d u a l t h r o a t c o n s t r i c t i o n f o r the  of c o - c u r r e n t g a s / s o l i d who  and  p o s t u l a t e d that  to reach the h i g h e r t h r o a t v e l o c i t y .  a c o n s t r i c t i o n type  (1953),  I t was  t h r o a t c o n s t r i c t i o n which p e r m i t t e d  permit  sensitive  p o s s i b l e to determine the gas  a b i l i t y of a flow n o z z l e to measure s o l i d s  throat v e l o c i t y .  f o r an  In  T h e r e f o r e , by u s i n g a flow n o z z l e i n c o n j u n c t i o n  p l a t e i t was  higher  diameter  s o l i d s f l o w i n g with the  f o r a flow n o z z l e was  f l o w r a t e s of a c o - c u r r e n t g a s / s o l i d  gradual  the  type flowmeter f o r measuring  that the p r e s s u r e d i f f e r e n t i a l  However, the p r e s s u r e d i f f e r e n t i a l gas  equipment p e r m i t t e d  s u c c e s s f u l l y demonstrated by C a r l s o n (1948). found  a  flowrate i n a The  principle  orifice  the f e a s i b i l i t y of u s i n g an o r i f i c e with  counter-current flowing g a s / s o l i d s suspension.  The  a  flows was  t h a t a v e n t u r i was  s o l i d s c a r r i e d with gas  f u r t h e r demonstrated by  capable  f l o w i n g through  Farbar  of measuring the f l o w r a t e of  the meter.  -39-  In the present simulated  CFB  behaviour  i n measuring s o l i d s  to measure s o l i d s f l u x e s r a n g i n g  counter-currently which simulated  the f l u i d i z a t i o n gas  Each m o d i f i e d  accumulation  fluxes.  2  o r i f i c e was  tubing.  t u b i n g , F i g u r e 2.14.  stack of d i s c s with  shown i n F i g u r e 2.13,  mm  thick acrylic  To d i s c o u r a g e  the 0.31  on 25.4 apart  mm  over  m lengths  s p a c i n g over the remaining  counter-current at  gas  immediately the next  0.31  ID p r e s s u r e upstream and  and  and  60°,  mm  solids  machined i n t o  inlet  taps spaced 12.7  measured u s i n g a rotameter  mm  orifice, mm  the introduced  flow of a i r  equipped with a needle  apart  50.8  s o l i d s r e t u r n s t a n d p i p e , was The  tap  and  downstream of the  A i r , to s i m u l a t e  m  the  diameter p r e s s u r e The  as  constructed  m i n each d i r e c t i o n , and  the bottom of the e x i t pipe of the apparatus.  regulated  straight  of repose of the  tube w a l l .  l e n g t h s of each p i p e .  flow i n the CFB  of 30°, 45°  s e c t i o n was  p o r t which a l i g n e d with a hole i n the housing  over  m  solids  each o r i f i c e was  each d i s c equipped with a 3.2  mm  1.52  d i s c s housed i n a l e n g t h of 0.102  c o n i c a l entrance  e x i t pipes were equipped with 3.2  vertical  t h r o a t angles  As  The  m/s,  Equipment  f l a n g e d between two  i n the t h r o a t , the i n l e t  study.  to 0.03  i n the s o l i d s r e t u r n column.  Modified O r i f i c e  m ID a c r y l i c  from a s t a c k of 6.35 ID a c r y l i c  o r i f i c e s were  from 10 to 100 kg/m s f l o w i n g  measured from the h o r i z o n t a l , exceeded the angles used i n t h i s  The  their  to a low v e l o c i t y upwards moving a i r f l o w , up  2.3.1  runs of 0.102  o r i f i c e s were s t u d i e d under  r e t u r n v e s s e l o p e r a t i n g c o n d i t i o n s to determine  performance and designed  work, three m o d i f i e d  was  valve.  -40-  SOLIDS INLET/GAS OUTLET  ENTRANCE SECTION  MODIFIED  --EXIT  to  o  SOLIDS  F i g u r e 2.14  V  GAS  ORIFICE  SECTION  INLET  DISCHARGE  M o d i f i e d o r i f i c e meter a p p a r a t u s . A l l dimensions shown are i n mm.  -41-  2.3.2 Pressure capacitance  pressure  transducer  model 51E01  i n terms of c o r r e s p o n d i n g  6150  Measurement  d i f f e r e n t i a l s were measured u s i n g a D i s a model 51D20  t u n i n g plug and  while  Pressure  i n c o n j u n c t i o n with a D i s a model 51E02-2  reactance  converter.  differentials,  v o l t a g e s , were d i s p l a y e d on a d i g i t a l  permanent r e c o r d s were made u s i n g an EMI Mk  Pressure  I I , chart recorder  (see F i g u r e  2.3.3  UV  voltmeter,  O s c i l l i o g r a p h , model  2.7).  Solids  Feeding  S o l i d s were s u p p l i e d to the o r i f i c e apparatus u s i n g e i t h e r : feed  f u n n e l l o c a t e d at the s o l i d s  secondary c y c l o n e permitted  of the CFB  inlet  of the o r i f i c e  apparatus.  the f l o w r a t e of s o l i d s  to be e a s i l y c o n t r o l l e d .  s i m u l a t i o n of the c o n d i t i o n s which an o r i f i c e would  bottom of a l a r g e f u n n e l to the s o l i d s  provided  s o l i d s i n the f u n n e l was  flowed inlet  maintained  be  the  other  r e t u r n loop  of the m o d i f i e d  at a constant  of  i n the  orifice.  the i n v e n t o r y  of  l e v e l by adding s o l i d s  to  Solids flowrate  changing the diameter of the o r i f i c e used i n the f u n n e l .  experiments, the s o l i d s were c o l l e c t e d  modified  funnel  through an o r i f i c e  f u n n e l at the same r a t e as they were being d i s c h a r g e d .  these  the  a better  i n the s o l i d s  ensure the flow of s o l i d s from the f u n n e l d i d not v a r y ,  v a r i e d by  On  solids  experience.  I n the f i r s t method, poured s o l i d s  To  A  apparatus or  S o l i d s f e e d i n g v i a the  hand, f e e d i n g of s o l i d s from the secondary c y c l o n e  a CFB  SE  o r i f i c e meter so that the s o l i d s  determined.  i n a b i n at the base of  was  During the  f l o w r a t e through the meter c o u l d  -42-  Gas the to  and e n t r a i n e d s o l i d s e x i t i n g  secondary c y c l o n e .  Solids  the f a s t bed were sent d i r e c t l y to  separated by the secondary c y c l o n e were f e d  the o r i f i c e assembly through a 0.102 m f l e x i b l e hose.  flow e x i t i n g  gas/solids  from the secondary c y c l o n e was sent to the primary and  t e r t i a r y c y c l o n e s of the CFB u n i t exhausted to atmosphere. a d j u s t e d by v a r y i n g  Solids  f o r further  s o l i d s removal and then  f e e d r a t e by the secondary c y c l o n e was  the s o l i d s l o a d i n g o f the gas e n t e r i n g the c y c l o n e .  T h i s was accomplished by c o n t r o l l i n g L-valve.  The  While s e t t i n g  the s o l i d s c i r c u l a t i o n r a t e  up the e x p e r i m e n t a l c o n d i t i o n s ,  through the o r i f i c e were r e c i r c u l a t e d  to the CFB u n i t .  solids  u s i n g the  passing  When steady  state  c o n d i t i o n s were a c h i e v e d , s o l i d s p a s s i n g through the apparatus were collected  i n a b i n a t t a c h e d to the end of the e x i t p i p e of the equipment  over a measured p e r i o d of time.  2.4 An  additional  L-valve  Calibration  area of i n t e r e s t was the r e l a t i o n s h i p  between the  v e l o c i t i e s of p a r t i c l e s moving downward through the v e r t i c a l s e c t i o n L - v a l v e and the c o r r e s p o n d i n g s o l i d s c i r c u l a t i o n r a t e . circumferential velocity In  p o i n t of measurement on the r e l a t i o n s h i p  and s o l i d s  f l u x was a l s o  horizontal  between p a r t i c l e  determined.  positions,  a t 45° i n t e r v a l s  l e g of the L - v a l v e , F i g u r e 2.15.  determined by r e c o r d i n g the time r e q u i r e d 0.30  The e f f e c t of the  t h i s study, p a r t i c l e v e l o c i t i e s were measured at f i v e  circumferential  of the  m l e n g t h of the L - v a l v e , s t a r t i n g  starting  different  In l i n e w i t h the  P a r t i c l e v e l o c i t i e s were  f o r a p a r t i c l e to move through a  1.3 m above the base of the v a l v e .  C o l o u r e d alumina or sand p a r t i c l e s , which were darker than the bulk of the  -43-  /^~~\  UPFLOW COLUMN  NEOPRENE "COLLAR  L-VAiVE HORIZONTAL LEG  POSITION 5 POSITION 4 POSITION 3 + POSITION 2 POSITION 1  Figure  2.15  P a r t i c l e v e l o c i t y measurement  L-VALVE VERTICAL SECTION  positions  -44-  p a r t i c u l a t e m a t e r i a l , were used to f o l l o w the movement of the through the v a l v e . butterfly  S o l i d c i r c u l a t i o n r a t e s were measured w i t h  pressure  Tecmar A/D, XT  the  valve.  2.5 The  solids  D/A  computer.  Data A c q u i s i t i o n and  transducer  and  load beam s i g n a l s were datalogged  programmable d a t a l o g g i n g  The  Processing using  board i n c o n j u n c t i o n with an  programs used to set and  start  the c l o c k and  per  T h i s program was  second, but was  logged  data  to the hard The  limited  capable  of sampling up  d i s k of the IBM  l o a d beam was  XT  at a r a t e of 100  A f t e r each run,  of each  out  f o r comparison purposes.  The  s i g n a l about the time averaged v a l v e was i n Appendix Pressure  second f o r a using  The i n t e g r a t i o n  i n t e g r a t i o n was  also  carried  d e v i a t i o n of the l o a d beam  c a l c u l a t e d using  the program shown  A.4. transducer  measurements of the p r e s s u r e  the o r i f i c e meter were datalogged minute run d u r a t i o n . outlined  The  the data were I n t e g r a t e d  Trapezoidal standard  points  run.  p o i n t s per  Simpson's method to determine the average s i g n a l v a l u e . program i s shown In Appendix A.3.  A.2  sampling and t r a n s f e r r e d  computer at the end  datalogged  1 to 2 minute run d u r a t i o n .  to 30000 data  to t a k i n g 27000 data p o i n t s per r u n .  p o i n t s were s t o r e d i n an a r r a y d u r i n g  IBM  to determine  the sampling r a t e of the Tecmar board are g i v e n i n Appendices A . l and respectively.  above.  at 100  a  p o i n t s per  differential  across  second f o r a 1 to 2  These s i g n a l s were then i n t e g r a t e d and  averaged  as  -45-  P r e s s u r e t r a n s d u c e r measurements g i v i n g a c r o s s the b u t t e r f l y v a l v e and period  accumulating  of 10 to 30 seconds at 100  sampling  p e r i o d was  fitted  s i n c e gas and  relatively  types of p a r t i c l e s were used an Ottawa sand  from  i n t h i s study:  s o l i d s were found and  found  liquid  The  from  r e c o r d i n g the volume. On  The  The  The  the alumina F i g u r e s 2.18  and and  p i l e s of s o l i d s .  sand 2.19  The  was  i n t o a measured volume of minimum  fluidization (Grace, 1982)  and  data,  by measuring the s l o p e s of  shapes and  s u r f a c e t e x t u r e s of  p a r t i c l e s are shown i n F i g u r e s 2.16 respectively.  graduated  particle density  m ID bed u s i n g p r e s s u r e drop  angles of repose were found  the s i d e s of poured  into a  the other hand, the sand  v e l o c i t i e s were e s t i m a t e d u s i n g an e m p i r i c a l c o r r e l a t i o n  Appendix C.  of  p a r t i c l e d e n s i t y of the alumina  r e c o r d i n g the d i s p l a c e d volume.  measured e x p e r i m e n t a l l y i n a 0.15  2.1.  l o o s e packed bulk d e n s i t i e s of the  by p o u r i n g a weighed amount of s o l i d s  and  i n Table  Illinois.  the s i e v e a n a l y s i s  by pouring a weighed amount of s o l i d s  by mercury p o r o s i m e t r y .  produced  the Ottawa Sand Company, Ottawa,  were c a l c u l a t e d  the s o l i d s g i v e n i n Appendix B.  found  through  data were  an alumina  r e s p e c t i v e p r o p e r t i e s of the p a r t i c l e s are summarized  cylinder  solids  s o l i d s would escape The  short  Particle Properties  Sauter mean p a r t i c l e diameters  was  The  A.5.  by A l c a n and The  p o i n t s per second.  for a  l i n e u s i n g the l i n e a r r e g r e s s i o n program presented i n  2.6 Two  s o l i d s were datalogged  c y c l o n e r e t u r n l i n e i f i t became uncovered.  by a s t r a i g h t  Appendix  differential  chosen to a v o i d e x c e s s i v e d e p l e t i o n of the  i n v e n t o r y of the b u b b l i n g bed, the secondary  the p r e s s u r e  and  2.17  and  -46-  Table 2.1  Particle Properties  Property  Alumina  Mean P a r t i c l e  Diameter, op  Ottawa Sand  64  148  P a r t i c l e Density, p kg/m  3500  2650  Bulk  1140  1550  3  Density, kg/m  P  3  Loose Packed Voidage, e P a r t i c l e Terminal V e l o c i t y , I L , based on gas p r o p e r t i e s at 25 C, m/s Archimedes Number U  m  0.42  0.36  0.99  31  mf C a l c u l a t e d m/s  U £  *0.67  Experimental m/ s  Bulk D e n s i t y at Minimum F l u i d i z a t i o n , P f , kg/m m  Bed Voidage at Minimum Fluidization, £ f  290  0.006  0.023  0.010  0.021  1100  1500  0.69  0.43  30°  29°  m  Angle of Repose  * includes internal  v o i d s of p a r t i c l e s  -47-  F i g u r e 2.16  Photograph  of the alumina p a r t i c l e s  a t 400X  magnification  -48-  F i g u r e 2.17  Photograph  of the alumina p a r t i c l e s at 2000X m a g n i f i c a t i o n  -49-  F i g u r e 2.18  Photograph of the sand p a r t i c l e s at 200X m a g n i f i c a t i o n  -50-  F i g u r e 2.19  Photograph of the sand p a r t i c l e s at 2000X m a g n i f i c a t i o n  -51-  3.0  R e s u l t s and D i s c u s s i o n  3.1 In t h i s chapter and  discussed.  CFB u n i t and  the experimental  The f i r s t  d i s c u s s the r e s u l t s  of t h i s work.  and o b s e r v a t i o n s  o r i f i c e meter and L - v a l v e  Throughout t h i s study  General  observations  the r e s u l t s  and t h e i r  of t h i s p r o j e c t are presented  The remaining  sections  of the present  f o r the impact flowmeter,  modified  calibration.  3.2  observations  results  s e c t i o n d e a l s with g e n e r a l o b s e r v a t i o n s  d u r i n g the course  i n d i r e c t l y affected  Introduction  effects  Observations of phenomena which d i r e c t l y and  of t h i s r e s e a r c h were r e c o r d e d .  These  are summarized i n t h i s s e c t i o n .  i 3.2.1 As a r e s u l t  of the p a r t i c u l a t e  w a l l s of the CFB u n i t , these  Static  Electricity  m a t e r i a l rubbing  s t a t i c charges were generated.  a g a i n s t the  The magnitude of  charges and r a t e of c h a r g i n g were dependent on the  m a t e r i a l , the humidity amount of s o l i d s  of the a i r used i n the f a s t  circulating  which they were t r a v e l l i n g .  particulate  and b u b b l i n g  beds, the  through the f a s t bed and the v e l o c i t i e s a t Charge g e n e r a t i o n was found  when the o u t s i d e a i r temperature and humidity  to be most  s t a t i c charges tended  to c o n c e n t r a t e  assembly which were i n i n t i m a t e c o n t a c t w i t h s c r e e n / b a f f l e assembly, primary  severe  was low, when the s o l i d s  c i r c u l a t i o n r a t e was h i g h and when the f a s t bed gas v e l o c i t y The  plexiglass  was  high.  on the p a r t s of the column the p a r t i c l e s ,  such as the  c y c l o n e , impact flow meter, b u t t e r f l y  valve  -52-  and  p l e x i g l a s s w a l l s c o n t a i n i n g the b u b b l i n g  discharges grounded  would occur  support  from these  structure.  computer d a t a l o g g i n g  s p i k e s i n the output  These d i s c h a r g e s  Discharges  At times,  primary c y c l o n e , electrically wire.  As a  r e s u l t e d i n the  shocks whenever she/he went to c l o s e  the shocks were so i n t e n s e  that i t was too  the v a l v e .  the problems of s t a t i c  discharge,  the b u t t e r f l y  valve,  s c r e e n / b a f f l e assembly and impact flow meter were  grounded to the support  T h i s prevented  equipment.  the  s p i k e was encountered.  on the b u t t e r f l y v a l v e  r e c e i v i n g high v o l t a g e  alleviate  a f f e c t e d the  from the column r e s u l t e d i n v o l t a g e  ceased when a v o l t a g e  uncomfortable to operate To  adversely  to the  the a n a l o g - t o - d i g i t a l c o n v e r s i o n s .  A d d i t i o n a l l y , charge accumulation  the v a l v e .  of charge c o n c e n t r a t i o n  electrical  s i g n a l of the load beam a m p l i f i e r which prevented  Tecmar board from completing  valve operator  Periodically,  and o p e r a t i o n of the impact flowmeter and the  operation b u t t e r f l y valve.  r e s u l t , datalogging  areas  bed.  static build  column u s i n g a heavy gauge copper  up and d i s c h a r g e  The r e t u r n column at the b u b b l i n g  from these  pieces of  bed s u r f a c e and immediately  upstream and downstream of the impact flowmeter and the s e c t i o n of the upflow column adjacent  to the impact flowmeter were covered  f o i l which was grounded to the support away from the covered electrical with  areas  structure.  the s h i e l d s of the c a b l e s  connected  aluminum  T h i s drew the charge  of the p l e x i g l a s s columns.  s i g n a l c a b l e s were r e p l a c e d w i t h  with  A l l of the  shielded e l e c t r i c a l  to an e l e c t r i c a l  cables,  ground.  -53-  The  e x t e n s i v e grounding of the CFB u n i t  operate without problems  allowed the equipment  except on days when the o u t s i d e temperature  below 0° c e l c i u s and the r e l a t i v e h u m i d i t y was days, s t a t i c observed.  These d i s c h a r g e s a d v e r s e l y a f f e c t e d  To reduce t h i s problem,  into  than 70%.  to the blower a i r l i n e .  S i n c e the water was  On these areas were  a i r was  The water was  to decrease the s t a t i c  added  evaporated  charge  batchwise to the blower l i n e ,  e f f e c t i v e n e s s of t h i s method decreased w i t h time between a d d i t i o n s . a l s o proved i n c o n v e n i e n t to add water p e r i o d i c a l l y antistatic  agent, ethylhexadecyldimethylammonium  water, was  a l s o evaporated i n t o  noticeable static  Under c o n d i t i o n s of h i g h s t a t i c that  bromide  r e l a t i v e h u m i d i t y were  change.  As s t a t i c  i n c r e a s e d , an i n c r e a s i n g amount of s o l i d s c o l l e c t e d r e t u r n columns. static  charges  c o n d i t i o n s , i . e . e x t e r n a l temperature of -3°C and 60% shaped v o i d s were seen to form and  charge appeared  low.  on the w a l l s of the the worst  relative  t r a v e l downwards i n  the b u b b l i n g bed f o r short d i s t a n c e s b e f o r e d i s a p p e a r i n g . static  not  observed  For the case of the Ottawa sand, o p e r a t i n g under  humidity, i r r e g u l a r  An  in a  was  charge g e n e r a t i o n , i t was  the behaviour of the s o l i d s would  It  dissolved i n  T h e r e f o r e , the equipment  operated when the o u t s i d e temperature and  the  to the blower l i n e .  the flow a i r but d i d not r e s u l t  charge r e d u c t i o n .  was  the d a t a l o g g i n g procedure.  the h u m i d i t y of the f l u i d i z i n g  the f l o w i n g a i r . T h i s appeared  generation.  less  d i s c h a r g e s from the p l e x i g l a s s column to grounded  i n c r e a s e d by adding water  to  The b u i l d - u p of  to make the s o l i d s more c o h e s i v e and p e r m i t t e d the  f o r m a t i o n of agglomerates which were able to w i t h s t a n d h i g h e r shear.  -54-  3.2.2 The  Circulation  most e f f e c t i v e method of s e t t i n g  c i r c u l a t i o n r a t e was found this  Solids  to d i f f e r  and a d j u s t i n g the s o l i d s  f o r the two types  of s o l i d s used i n  study. To  circulate  the alumina  p a r t i c l e s , i t was necessary  to a e r a t e the  solids  i n the v e r t i c a l and h o r i z o n t a l l e g s of the L - v a l v e b e f o r e  solids  f e e d i n g c o u l d be o b t a i n e d .  b e g i n a e r a t i n g the s o l i d s F i g u r e 2.2. observed time,  bed.  s t a r t - u p , the f i r s t  step was to  i n the v e r t i c a l l e g u s i n g a e r a t i o n p o i n t #16,  When the a i r f l o w to p o i n t #16 was s t a r t e d , the s o l i d s  fell  from the lower  The gas was a b l e to flow f r e e l y  immediately  through  t r a v e l l i n g upward through  the s o l i d s  the f i r s t  to the b u b b l i n g below the b r i d g e ,  0.30 m of s o l i d s  above the a e r a t i o n p o i n t and then d i s p e r s i n g so t h a t d e t e c t a b l e  v o i d s were not observed  to flow through  the s o l i d s  above t h i s p o i n t .  the b r i d g e had d i s a p p e a r e d ,  the s o l i d s  However, the flow of s o l i d s  o c c u r r e d i n p u l s e s , w i t h the s o l i d s  in  With  s u r f a c e of the b r i d g e and the b r i d g e was  to t r a v e l up the v e r t i c a l l e n g t h of the L - v a l v e  w i t h bubbles  and  were  to b r i d g e the 0.15 m column d i r e c t l y above the a e r a t i o n t a p .  solids  observed  During  continuous  slipping  as they moved through  began to flow through  the L - v a l v e .  Once  the L - v a l v e . sticking  At t h i s p o i n t , the s o l i d s  the h o r i z o n t a l l e g of the L - v a l v e were a e r a t e d u s i n g a e r a t i o n p o i n t s #1  through  #4, F i g u r e 2.2.  through  the L - v a l v e .  This resulted  i n the s o l i d s moving more smoothly  However, as the s o l i d s  increased,  the s o l i d s were found  the v a l v e .  Adjustment of s o l i d s  the a i r flow to p o i n t #5.  c i r c u l a t i o n r a t e was  to s t i c k and s l i p as they  flowed  through  c i r c u l a t i o n was p r i m a r i l y by r e g u l a t i n g  Minor flow adjustments were a l s o made by v a r y i n g  the a i r f l o w s to p o i n t s #6 and #7.  -55-  R e i n j e c t i o n of the Ottawa sand u s i n g simpler using  a e r a t i o n p o i n t s #6 and #7 i n F i g u r e  aerate solid the  than c i r c u l a t i o n of the alumina.  the s o l i d s  the L - v a l v e  S o l i d s c i r c u l a t i o n was c o n t r o l l e d 2.2.  I t was not necessary to  i n the v e r t i c a l or h o r i z o n t a l l e g s of the L - v a l v e .  c i r c u l a t i o n r a t e was i n c r e a s e d  two a e r a t i o n p o i n t s .  alumina, the f l o w r a t e s  by i n c r e a s i n g the f l o w r a t e  narrow l e n s between the two a e r a t i o n p o i n t s . Increased  Periodically,  w i t h i n c r e a s i n g a i r flow  to have a s i g n i f i c a n t e f f e c t  bubble i n a b u b b l i n g  on the s o l i d s  a p a r a b o l i c , concave  The l e n g t h which the v o i d to the two a e r a t i o n  points.  T h i s was not observed  circulation rate.  the shape of the v o i d became s i m i l a r f l u i d i z e d bed.  As the s o l i d s  to that of a gas  At c i r c u l a t i o n r a t e s l e s s  than 20  2  kg/m s, s o l i d s movement through the v a l v e was c o n t i n u o u s , with only f l u c t u a t i o n s i n feedrate increased  past  being  observable.  For the  The v o i d was i n the form of a  the v o i d c o l l a p s e d and then reformed.  f l u x was i n c r e a s e d ,  of a i r to  to the two a e r a t i o n p o i n t s were kept e q u a l .  formed between the two a e r a t i o n p o i n t s .  occupied  The  During a l l the experiments w i t h the sand and the  case of the sand, as the a e r a t i o n r a t e was i n c r e a s e d , void  tended to be much  small  As the c i r c u l a t i o n r a t e was  these r a t e s , the flow o f s o l i d s was found to f l u c t u a t e .  T h i s may have been due to the onset of choking i n the f a s t bed column at the h i g h e r  solids  c i r c u l a t i o n r a t e s which would have r e s u l t e d i n p r e s s u r e  f l u c t u a t i o n s which c o u l d have caused v a r i a t i o n s i n s o l i d s  feeding.  -56-  3.3  Impact Flowmeter R e s u l t s and  In t h i s s e c t i o n the o b s e r v a t i o n s a r e presented  and  of the behaviour subsections  discussed. of the impact  are d e d i c a t e d  r e s u l t s obtained  The  different  subsection deals with  flowmeter d u r i n g o p e r a t i o n .  u s i n g the impact  low  General  shows t y p i c a l responses of the impact flowmeter to  at low  frequency,  solids with  f l u x e s , the pan was  the displacements  sand f o r every found  magnitude.  T h i s type pan.  As  observed  to f l u c t u a t e at  from the zero  of response was  position  to the order of seconds between observed  f o r both  the s o l i d s c i r c u l a t i o n r a t e was  to o s c i l l a t e with a h i g h e r  S i g n a l t r a c e s and  pan  frequency  observations  and w i t h  not appear to be of a r e g u l a r frequency.  The  i t was  oscillations  alumina  increased,  the  greater  showed the pan  more time away from the zero p o s i t i o n , but,  to i t s o r i g i n a l p o s i t i o n between peaks.  as  remaining  Observations  them, F i g u r e s 3.1a.  spending  The  flowmeter.  p e r i o d s up  pan was  observations  a n a l y s i s of the q u a n t i t a t i v e  o c c u r r i n g as s i n g l e peaks with  and  flowmeter  circulation rates.  Initially, a very  first  r e s u l t s of the impact  to p r e s e n t a t i o n and  3.3.1 F i g u r e 3,1  and  Discussion  to be  still  returning  of the pan  D e f l e c t i o n s were found  to  did occur  s i n g l e p u l s e s , with v a r y i n g time i n t e r v a l s between p u l s e s , and/or as a  s e r i e s of p u l s e s i n r a p i d s u c c e s s i o n , with o v e r l a p of deflections. less  Qualitatively,  i t appeared  s e n s i t i v e w i t h i n c r e a s i n g pan  angle.  successive  that the pan's response became However, comparison of  the  -57-  d) G = 35.1 s  kg/m*s  c) G =19.3 k g / m s 2  s  1.33 N  a ) G = 5 . 1 kg/nfs s  t=0 36 s e c o n d s  F i g u r e 3.1  E f f e c t o f s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on o s c i l l a t i o n of the 30° pan with sand, U = 0.024 m/s, Uf = 5.0 m/s. s  -58-  traces f o r d i f f e r e n t  pan angles d i d not a l l o w t h i s o b s e r v a t i o n to be  supported because the s i g n a l s With i n c r e a s i n g  solids  fluctuated  rapidly  c i r c u l a t i o n rate,  with l a r g e  F i g u r e s 3.1c and 3.Id, the load  beam s i g n a l was seen to peak ( i . e . reach a l i m i t i n g v a l u e ) . was the r e s u l t it The  of the l e v e r  deflecting  This  peaking  the load beam to such an extent  that  c o n t a c t e d a mechanical stop which prevented o v e r l o a d i n g of the beam. f r a c t i o n of time d u r i n g which the s i g n a l  solids  c i r c u l a t i o n rate increased.  was peaked i n c r e a s e d as the  The c i r c u l a t i o n r a t e at which peaking  o c c u r r e d was found to i n c r e a s e with i n c r e a s i n g f o r alumina than f o r sand. the  amplitudes.  load beam a m p l i f i e r  displaced studied, The  pan angle and i t was h i g h e r  At the h i g h e r c i r c u l a t i o n r a t e s ,  signal  the t r a c e s of  showed the pan to be spending more time  from i t s o r i g i n a l p o s i t i o n .  At the h i g h e s t c i r c u l a t i o n  rates  the pan was found to be peaked f o r the m a j o r i t y of the time. t y p i c a l response of the Impact flowmeter to c i r c u l a t i n g s o l i d s i s  shown i n F i g u r e 3.2.  This figure  shows the response of the pan over a 1  second p e r i o d with the photographs being taken at 1 second i n t e r v a l s . results  The  show that the pan o s c i l l a t e s i n the v e r t i c a l plane when s o l i d s are  f l o w i n g over i t In the downward d i r e c t i o n .  T h i s type of response was  observed f o r a l l of the pan angles with both the alumina and sand being circulated.  However, the frequency and amplitude of the f l u c t u a t i o n s  found to change w i t h the s o l i d circulation  the pan angle and s o l i d s  rate.  Originally, to be d e f l e c t e d  i t was hoped that c i r c u l a t i o n s o l i d s would cause each pan from i t s r e s t i n g  s i g n a l would show a f l u c t u a t i n g the  being c i r c u l a t e d ,  were  no-load s i g n a l  value.  position  and the t r a c e of the load beam  s i g n a l w i t h an average v a l u e o f f s e t  As the s o l i d s  from  c i r c u l a t i o n r a t e was i n c r e a s e d the  -59-  3.2  Photographs of the o s c i l l a t i n g impact flowmeter 60° pan w i t h sand, U = 0.024 m/s, Uf = 6.0 m/s, G = 25 kg/m s, based on the f a s t bed c r o s s - s e c t i o n a l a r e a . 2  s  s  -60-  d i f f e r e n c e between the average was  s i g n a l v a l u e and  expected to i n c r e a s e m o n i t o n i c a l l y .  through 3.Id,  i n c r e a s e d i n amplitude and f r e q u e n c y as the s o l i d s  c i r c u l a t i o n rate increased. o b s e r v a t i o n s of the impact  The  t r a c e s are i n agreement w i t h the  flowmeter which a l s o showed the equipment t o  oscillations.  Three p o s s i b l e e x p l a n a t i o n s may meter:  However, as shown by F i g u r e s 3.1a  the pan's responses w i t h time were found to be composed of a  s e r i e s of peaks which  undergo  the no-load s i g n a l v a l u e  During o p e r a t i o n , the s o l i d s  e x p l a i n the behaviour of the impact f l o w r a t e through the f l e x i b l e  hose  c o n n e c t i n g the f a s t bed exhaust p o r t to the primary c y c l o n e i n l e t was to p u l s a t e .  The  p u l s a t i o n s became i n c r e a s i n g l y e v i d e n t as the  c i r c u l a t i o n r a t e was acrylic  increased.  solids  O b s e r v a t i o n s of the flow through the  sampling tube i n the f l e x i b l e hose, F i g u r e 2.1,  showed  solids  a c c u m u l a t i n g In the s e c t i o n tube f o r a p e r i o d r a n g i n g from 1 to 2 and  then being blown out of the p i p e v e r y r a p i d l y .  itself.  The  found  p e r i o d of the c y c l e d i d not appear  The c y c l e then r e p e a t e d  to be a f f e c t e d  by the b u b b l i n g bed or f a s t bed gas v e l o c i t i e s or the s o l i d s r a t e s over the range of c o n d i t i o n s s t u d i e d .  seconds  As a r e s u l t  appreciably  circulation  of the p u l s a t i n g  f l o w through the f l e x i b l e hose, the s o l i d s e n t e r e d the primary c y c l o n e w i t h periodic pulsations.  Thus, the flow of s e p a r a t e d s o l i d s  a l s o showed p u l s a t i o n s . flowmeter  signal fluctuations.  oscillations s o l i d s was unlikely meter.  T h i s may  from the c y c l o n e  have been one of the causes of the Impact  However, s i n c e the frequency of the meter  i n c r e a s e d w i t h s o l i d s c i r c u l a t i o n r a t e , but the p u l s i n g of the  not s i g n i f i c a n t l y  a f f e c t e d by changing c o n d i t i o n s ,  to be the e n t i r e cause of the f l u c t u a t i n g  this i s  s i g n a l of the  impact  -61-  Solids  from the primary c y c l o n e were observed to move as a  concentrated as  stream along a h e l i c a l path, near the r e t u r n v e s s e l ' s  they r e t u r n e d  F i g u r e 3.3.  to the b u b b l i n g bed of the s o l i d s  The p a r t i c l e s  s l o w l y d i s p e r s e d as they f e l l  through the upward f l o w i n g gas. the  the  solids  of the b a f f l e ' s  action,  The t r a j e c t o r y  strike  changed, F i g u r e 3.4.  the s i d e of the pan c l o s e s t  T h i s c o u l d have c o n t r i b u t e d  were observed f o r the impact A third factor,  of the  c i r c u l a t i o n r a t e and  likely  to the f r o n t  of the  of the s o l i d s  flow  to the f l u c t u a t i o n s  which  flowmeter. to be s i g n i f i c a n t , i s that p a r t i c l e s  were  At h i g h e r c i r c u l a t i o n r a t e s i t was not p o s s i b l e to  observe the pan because of the dense flow of s o l i d s . a run w i t h a h i g h s o l i d s on the pan.  frequency of s o l i d s solids  solids  2.2.2).  to accumulate on and d i s c h a r g e from the pan at low s o l i d s  c i r c u l a t i o n rates.  the  solids  However, the s o l i d s were always observed to  column, but i n d i f f e r i n g amounts as the t r a j e c t o r y  resting  The  the m a j o r i t y of the s o l i d s were found  the pan near i t s c e n t r e on one s i d e .  preferentially  exiting  away from the column's w a l l by the b a f f l e which c o n c e n t r a t e d  f a s t bed gas v e l o c i t y .  of  flow  by the s c r e e n .  s o l i d s was found to change s l i g h t l y with time, s o l i d s  observed  counter-currently  i n the c e n t r e of the column, F i g u r e 2.13 (see s e c t i o n  As a r e s u l t to s t r i k e  vessel,  The p u l s a t i o n s i n the s o l i d s  primary c y c l o n e d i d not seem to be a f f e c t e d  were d i r e c t e d  inventory  wall,  c i r c u l a t i o n rate,  some s o l i d s were found to be  The r a t e and amount of s o l i d s discharged  c i r c u l a t i o n rate.  appeared  accumulation and the  to be a f f e c t e d  For i n c r e a s i n g  However, at the end  by the pan angle and  pan angles the amount of  accumulating on the pan was found to d e c r e a s e .  T h i s was to be  -62-  F i g u r e 3.4  End view photograph showing sand s t r i k i n g the 60° pan U = 0.024 m/s, U = 6.0 m/s, G = 25 kg/m s, b a s e d on t h e f a s t b e d c r o s s - s e c t i o n a l a r e a . 2  s  f  s  -63-  expected, s i n c e the r e s p e c t to  the  angle of  With i n c r e a s i n g and  s l o p e s of  solids  Solids  solids  l o a d i n g of  repose of  the  two  from the  on  affecting  not  solids  The  the  pan  effect  is plausible  s t a t i c charge.  to being d i s l o d g e d by  that v a r i a t i o n s  amount of  solids  solids  experimental  i n the  the  explanations. 3.2.2) and  by  pan,  and  accumulating on  exact cause of  remains u n c e r t a i n , the  fluctuations  the  pattern.  different  I t Is a l s o As  the  shear.  may  the  result pan  in  of  to  section  s o l i d s more  I f t h i s i s the  s t a t i c charge of  type  important  discussed  and  the  case,  p a r t i c l e s , as  a  affect  i n s i g n i f i c a n t changes i n  at d i f f e r e n t  points i n  an  run.  Although the  p a r t of  on  of  observed s e p a r a t e l y from  signal.  pan  of d i s c h a r g i n g  of changing humidity and/or s t a t i c d i s c h a r g e , c o u l d  accumulation of  at  the  impact meter, i t i s e v i d e n t that t h i s  in a fluctuating  resistant  method  appear to f o l l o w a f i x e d  Although the be  studied.  a c c u m u l a t i o n on  from a l l areas of  c o u l d not  the  the  materials  presence of a s t a t i c charge seems to make the  c o h e s i v e and  result  pan  p o s s i b l e i n f l u e n c e of  3.2.1, the  did  slide off  the  response would r e s u l t note the  pan  particulate  found to i n c r e a s e .  i n v a r y i n g amounts.  solids  other variables  or  s u r f a c e s were becoming l a r g e with  c i r c u l a t i o n rate,  were observed to  f r e q u e n c i e s and  the  pan  d i s c h a r g e frequency were a l s o  d i s c h a r g e of  it  the  cause of  the  impact meter s i g n a l  suggested e x p l a n a t i o n s may the  were caused by  observed f l u c t u a t i o n s . a combination of  Variations in solids turbulent fluctuations  have p l a y e d a s i g n i f i c a n t  w e l l be  role.  the  the  entire  cause  In a l l l i k e l i h o o d ,  above three  f l u x caused by i n the  fluctuations  the  f a s t bed  suggested  L-valve  gas  the  (see  v e l o c i t y may  Section also  -64-  The  results  3.3.2  Impact Flowmeter R e s u l t s  the  impact flowmeter to changing  of  c i r c u l a t i o n r a t e s f o r the  three pan  F i g u r e 3.5  through 3.10.  The  f o r c e s and  solids  angles and  two  c i r c u l a t i o n r a t e s were converted according  Appendix E.  f o r c e r e p r e s e n t s the  to  the  pan  •effective  by  which i s the on  the  to be  pan 230  pivot. the  impacting p a r t i c l e s  to mm,  pivot.  the  d i s t a n c e from the  butterfly first  F(t) • X. " "TTeff  = t/  t + A t  F  e  J  the  e  was  pan  force  acts  assumed to the  f o r c e measured by the  the  X ff,  effective  e  imparted  determine  the  effective  lever load beam,  particle  n = ill  f  f  (  t  )  d  cross-sectional valve.  the  P. V - T T eff  F ( t )  (3.3.1)  force i s given  by:  t  ,3 3 2^ (3.3.2)  EE  butterfly  calculate  To  study, X f f  and  their  average f o r c e  Instant.  c e n t r e of  impacting p a r t i c l e s  c i r c u l a t i o n r a t e s are  f a s t bed  this  between the  time-averaged e f f e c t i v e  Solids  In  flowmeter  follows:  ^ e f f  Fe f f  from  shown i n  procedures shown i n  p o i n t at which the  lever  f o r c e caused by  F  at any  the  relationships  as  to the  are  impact  i t i s necessary to assume a v a l u e of  d i s t a n c e from the  The  f o r c e are  The  effective  force,  solids  time-averaged e f f e c t i v e  equivalent voltage signals The  solids  For  the  expressed as  area and  solids  f l u x e s based on  were measured by  reasons e x p l a i n e d  accumulation on  In s e c t i o n  3.6,  only  v a l v e c i r c u l a t i o n r a t e measurements were used  solids  fluxes.  the  to  the  the  -65-  12  24  36  48  60  SOLIDS FLUX (kg/m s) 2  F i g u r e 3.5  I n f l u e n c e of s o l i d s f l u x , b u t t e r f l y v a l v e and based a r e a , on e f f e c t i v e f o r c e U = 0.014 m/s, U = 3.0 s  f  measured by accumulation on the on the f a s t bed c r o s s - s e c t i o n a l f o r the 30° pan with alumina, t o 5.3 m/s.  -66-  1.25  0  16  8  24  32  40  SOLIDS FLUX (k /m s) 2  9  F i g u r e 3.6  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on e f f e c t i v e f o r c e f o r the 45° with alumina, U = 0.014 m/s, U = 3.2 to 3.8 m/s. s  f  pan  -67-  0.60  12  0  24  36  48  60  SOLIDS FLUX (kg/m s) 2  F i g u r e 3.7  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on e f f e c t i v e f o r c e f o r the 60° pan with alumina, U = 0.014 m/s, Uf = 3.0 to 4.4 m/s. s  -68-  1.25  16  8  24  32  40  SOLIDS FLUX (kg/m*s)  F i g u r e 3.8  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on e f f e c t i v e f o r c e f o r the 30° pan w i t h sand, U = 0.024 m/s, U = 3.5 to 5.0 m/s. s  f  -69-  16  8  24  32  40  SOLIDS FLUX (k /m s) 2  9  F i g u r e 3.9  I n f l u e n c e o f s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on e f f e c t i v e f o r c e f o r the 45° pan w i t h sand U = 0.024 m/s, Uf = 3.0 to 6.6 m/s. s  -70-  1.25  16  8  24  32  40  SOLIDS FLUX (k /m s) 2  9  F i g u r e 3.10  I n f l u e n c e of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on e f f e c t i v e f o r c e f o r the 60° pan w i t h sand U = 0.024 m/s, Uf = 4.7 to 5.5 m/s. s  -71-  The  time-averaged load beam s i g n a l s  significantly  were found, i n some cases, to vary  (see the raw data i n Appendix F ) .  The g r e a t e s t  2  were found to occur a t i n t e r m e d i a t e c i r c u l a t i o n r a t e s , the  2  alumina and 10 to 30 kg/m s f o r the Ottawa sand.  fluctuations  10 t o 50 kg/m s f o r At these r a t e s , the  l o a d beam s i g n a l was found to be v e r y o s c i l l a t o r y , w i t h the amplitude of the by  fluctuations  being as g r e a t as 1.33N ( c o n v e r t e d from the s i g n a l  the procedure i n Appendix E ) .  differences solids  The p r o b a b l e causes of the observed  were that the d a t a l o g g i n g p e r i o d was too s h o r t and/or the  c i r c u l a t i o n varied  d u r i n g the e x p e r i m e n t a l run.  I t was not p o s s i b l e  to use a longer sampling p e r i o d due to computer l i m i t a t i o n s . variation  i n solids  controllable The  flux,  discussed  i n section  problem.  results  f o r the 30° and 60° pans f o r both the alumina and the  c i r c u l a t i o n r a t e s t h e r e i s an i n i t i a l  fluxes,  there i s a s e n s i t i v e  rapidly  with increasing  into  flux.  r e g i o n where the e f f e c t i v e  solids  flux.  three zones:  zone where the e f f e c t i v e  does not change s i g n i f i c a n t l y w i t h changing s o l i d s  effective  The p o s s i b l e  3.2.2, was not a  sand, F i g u r e s 3.5, 3.7, 3.8 and 3.10, can be d i v i d e d low  traces  At  force  At i n t e r m e d i a t e force  increases  At h i g h e r c i r c u l a t i o n r a t e s , the  f o r c e i s seen to be l e v e l l i n g o f f and r e a c h i n g a maximum v a l u e .  T h i s type of response was not apparent i n the r e s u l t s  of the 45° pan f o r  both the alumina and the Ottawa sand. In  the f i r s t  zone, the e f f e c t i v e  i n c r e a s e s i n the s o l i d s affected  circulation rate.  The extent of t h i s zone i s  by the type of s o l i d s b e i n g c i r c u l a t e d  alumina, t h i s zone p e r s i s t e d 30°  f o r c e does not seem to respond to  and 60° pans.  and the pan a n g l e .  For  2  f o r c i r c u l a t i o n r a t e s up to 35 kg/m s f o r the  With sand, the response was observed f o r c i r c u l a t i o n  -72-  2  r a t e s up likely being at  to 8 kg/m s f o r both the 30°  the  result  of f r i c t i o n a l  large with respect  low  solids  observed  and  60°  f o r c e of the p a r t i c l e s  circulation rates.  Both the  load beam was  extent  p r o p e r l y , was  caused by  the  zone was  and  most  end  to s t i c k .  The  on  the  pan  load beam were  However, i t was  of these r e s i s t a n c e s .  observed  sensing  impacting  lever bearing  to e x h i b i t r e s i s t a n c e to movement.  even when a d j u s t e d  This  f o r c e s , which opposed the pan movement,  to the  to measure the magnitude and  pans.  not  The  possible  bearing,  r e s i s t a n c e of  of the beam rubbing a g a i n s t  the  the  a l i e n screws used to a l i g n i t . In the  second r e g i o n ,  the  effective  changes i n the c i r c u l a t i o n r a t e . 60°  pans, w i t h both alumina and  increased  with increased  solids  p r e s e n t e d i n Appendix H the the pan  of the p a r t i c l e s  comparison of F i g u r e s of the  3.5  flux.  increase  shows that  60°  pan  angle c o u l d  pans.  and  Figures  3.8  3.10  c i r c u l a t i o n r a t e curves are  i t i s p o s s i b l e that  be d i s t i n g u i s h e d because of i n a c c u r a c i e s  measurements of the e f f e c t i v e  f o r c e s and  the  solids  of the  the Tecmar board.  occurred  load beam.  at h i g h e r  Signal clipping  of the  I t i s the Tecmar board o v e r l o a d i n g  of  i n the  circulation  c i r c u l a t i o n rates:  sand.  the e f f e c t  rates.  zone corresponds to the equipment becoming o v e r l o a d e d .  t y p e s of o v e r l o a d i n g  the  essentially  T h i s a p p l i e s f o r both alumina and  o b v i o u s , but  as  change i n the downward  and  reasons f o r t h i s are not  overloading  simple model  and  3.7  and  solids,  response curve should  of the g r e a t e r  30°  However,  The  final  f o r the  angles.  same f o r the  The  to the  s e n s i t i v e to  caused by decreased pan  the  not  and  circulating  According  slope of the  force versus s o l i d s 30°  found to be  expected, the r e s u l t s  sand as the  angle decreases as a r e s u l t  velocity  slopes  As  f o r c e was  Two  Mechanical  load beam s i g n a l by wich has  lead to  the  -73-  third  zone, apparent i n the r e s u l t s .  sampling  v o l t a g e s of 10 v o l t s  overloaded  or l e s s .  The Tecmar board  was r e s t r i c t e d to  When the equipment was m e c h a n i c a l l y  the load beam v o l t a g e was approximately  12 v o l t s .  v o l t a g e exceeded the maximum v o l t a g e of the Tecmar board 10 v o l t s .  T h i s maximum v o l t a g e corresponds  when converted higher  solids  according  c i r c u l a t i o n r a t e s the output  i t was recorded as  to an e f f e c t i v e  t o the procedure i n Appendix E .  When the  f o r c e of 1.11 N  S i n c e , at the  v o l t a g e of the load beam  a m p l i f i e r exceeded the 10 v o l t maximum of the Tecmar Board f o r a g r e a t e r f r a c t i o n of the time, effective  the time-averaged v o l t a g e  l e v e l l e d o f f and the  f o r c e approached 1.11 N which was e q u i v a l e n t to a 10 v o l t  beam a m p l i f i e r s i g n a l .  load  -74-  3.3.3 The  Standard D e v i a t i o n s  standard d e v i a t i o n s of the e f f e c t i v e f o r c e s f o r the t h r e e  a n g l e s and f a s t bed  two  s o l i d s v e r s u s the s o l i d s c i r c u l a t i o n r a t e s , based  through 3.16.  The  standard d e v i a t i o n s are  v e r s u s the e f f e c t i v e f o r c e , as measured by the impact F i g u r e s 3.17 the t h i r d  through  3.22.  The  solid  c i r c u l a t i o n rates,  through  3.16  l i n e s drawn on each f i g u r e r e p r e s e n t  the standard d e v i a t i o n s of the e f f e c t i v e  shows the pan  the meter's s i g n a l  f l u c t u a t i o n s to be s m a l l and  the f l u c t u a t i o n s of the pan are minor, v a r i a t i o n s also small.  all  At  low  response, infrequent.  T h e r e f o r e , standard d e v i a t i o n s of the e f f e c t i v e  Since  f o r c e s are  f o r c e s are  of the impact  meter  was  to f l u c t u a t e at a h i g h e r frequency with a g r e a t e r amplitude f o r  three pans and both types of s o l i d s .  depended on the pan angle and  solids  g r e a t e r s e n s i t i v i t y and, increasing  The  type.  f o r d e c r e a s i n g pan angles and with sand  through  squares.  f o r c e s are  in effective  As c i r c u l a t i o n r a t e s were i n c r e a s e d the pan  observed  in  a l l show s i m i l a r c h a r a c t e r i s t i c s .  At these c i r c u l a t i o n r a t e s ,  F i g u r e 3.1,  plotted  flowmeter,  order p o l y n o m i a l s which best f i t the data u s i n g l e a s t  F i g u r e s 3.11  small.  on the  c r o s s - s e c t i o n a l area and measured by the b u t t e r f l y v a l v e , are  shown i n F i g u r e s 3.11  small.  pan  increase i n fluctuations  The  more s e n s i t i v e  as the c i r c u l a t i n g m a t e r i a l .  thus, g r e a t e r i n c r e a s e i n f l u c t u a t i o n s  s o l i d s c i r c u l a t i o n r a t e are apparent  3.13  response was  or F i g u r e s 3.14  through  3.16  with  when the F i g u r e s  are compared.  The  3.11  Comparison of  these f i g u r e s shows that the standard d e v i a t i o n of the e f f c t i v e f o r c e s i n c r e a s e s more r a p i d l y as the angle of the pan decreases and  sand.  f o r both  alumina  T h i s agrees with the o b s e r v a t i o n s of the pan which showed that  d e c r e a s i n g the pan  angle r e s u l t e d  i n Increased frequency and  amplitude  of  -75-  0.5  i  I  |  i  |  12  0  24  i  |  36  i  |  48  i  60  SOLIDS FLUX (kg/m*s)  F i g u r e 3.11  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n o f the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan w i t h alumina, U = 0.014 m/s, U = 3.0 to 5.3 m/s. s  f  -76-  F i g u r e 3.12  E f f e c t of s o l i d s f l u x , based on the f a s t bed area, on standard d e v i a t i o n of the e f f e c t i v e f o r the 45° pan with alumina, U = 0.014 m/s, Uf = 3.2 to 3.8 m/s. s  cross-sectional force signal  -  12  0  24  7  7  -  36  48  60  SOLIDS FLUX (kg/m*s)  F i g u r e 3.13  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan with alumina, U = 0.014 m/s, U = 3.0 to 4.4 m/s. s  f  -78-  0  8  16  24  32  40  SOLIDS FLUX (kg/m s) 2  F i g u r e 3.14  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan w i t h sand, U = 0.024 m/s, Uf = 3.5 t o 5.0 m/s. s  -79-  0  8  16  24  32  40  SOLIDS FLUX (kg/m*s)  3.15  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 45° pan with sand, U = 0.024 m/s, Uf = 3.0 t o 6.6 m/s. s  -80-  3.16  E f f e c t of s o l i d s , based on the f a s t bed cross-sectional a r e a , on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan w i t h sand, U = 0.024 m/s, U = 4.7 to 5.5 m/s. s  f  Figure  3.17  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan w i t h alumina, U = 0.014 m/s, U = 3.0 to 5.3 m/s. s  f  -82-  o . 5 1 — i — | — i — | — i — | — i — r  EFFECTIVE FORCE (N)  F i g u r e 3.18  I n f l u e n c e o f the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 45° pan with alumina, U = 0.014 m/s, U = 3.2 to 3.8 m/s. s  f  -83-  *0.0  0.25  0.50  0.75  1.00  1.25  EFFECTIVE FORCE (N)  Figure  3.19  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan w i t h alumina, U = 0.014 m/s, Uf =3.0 to 4.4 m/s. s  -84-  Figure  3.20  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 30° pan with sand U = 0.024 m/s, Uf = 3.5 to 5.0 m/s. s  -85-  0.0  0.25  0.50  0.75  1.00  1.25  EFFECTIVE FORCE (N)  F i g u r e 3.21  I n f l u e n c e of the e f f e c t i v e f o r c e on standard d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 45° pan with sand, U = 0.024 m/s, U = 3.0 to 6.6 m/s. s  f  -86-  Figure  3.22  I n f l u e n c e of the e f f e c t i v e p a r t i c l e f o r c e on s t a n d a r d d e v i a t i o n of the e f f e c t i v e f o r c e s i g n a l f o r the 60° pan with sand, U = 0.024 m/s, Uf = 4.7 to 5.5 m/s. s  -87-  f l u c t u a t i o n s for a given and  3.12  and  effective  3.15  and  solids flux.  3.13  force increases  sand r a t h e r  and  3.16  Comparison of F i g u r e s  show that  the  standard  circulating  greater  same s o l i d s f l u x e s . standard  deviations  reflects  the  periods Since  As  the  the  s i g n a l could  was  permanently being  which the pan  becoming o v e r l o a d e d .  exceed a maximum of 1.11  N, which corresponds  from the  decreased and  standard  deviation reflects  decreasing  pan  angles.  This  3.17  through 3.22  In r e a l i t y  pan  angle was  The for  illustrate  i n the  small,  the  r e l a t i o n s h i p between the v a l u e s  r e s u l t s i t i s evident  the  at  decreased.  c a p a c i t y at which the  When the e f f e c t i v e f o r c e s are  not  i s because the equipment became overloaded  From the  the  then, the decrease i n  at lower c i r c u l a t i o n r a t e s  forces.  depend on  pan  fluctuations i n  c i r c u l a t i o n rates.  d e v i a t i o n s of the e f f e c t i v e f o r c e s and  deviations  the  the equipment becoming o v e r l o a d e d and  standard  similarity  the  to  p o s i t i o n , the range over  correspondingly,  deviations occurred  lower c i r c u l a t i o n r a t e s as the Figures  zero  s i g n a l q u a l i t y at h i g h e r  i n standard  longer  which the Tecmar Board c o u l d measure, and  the  reduction  This  the equipment was  that  e f f e c t i v e force s i g n a l s decreased.  improvement i n the  the  fact  the  an  the  from t h e i r  displaced  oscillated  (higher  seen to d e c r e a s e . positions for  was  displaced  not  the maximum s i g n a l value  fluctuations  s o l i d s c i r c u l a t i o n r a t e s were i n c r e a s e d  zero  the  This  sand than f o r the alumina at  of the e f f e c t i v e f o r c e s are  pans being  of time and  the  amplitude) f o r the  3.14,  angles when  particulate material.  expected, s i n c e a l l of the pans showed more v i g o r o u s frequency and  and  d e v i a t i o n of  much more q u i c k l y f o r a l l the pan  than alumina i s the  3.11  of the e f f e c t i v e t h a t the  equipment i s  standard  the  deviations  standard  operating. are  small.  As  -88-  the e f f e c t i v e f o r c e s i n c r e a s e equipment, the standard  to a p p r o x i m a t e l y 50% of the c a p a c i t y of the  d e v i a t i o n s i n c r e a s e to a maximum v a l u e .  c i r c u l a t i o n rates greater  than 50% of the c a p a c i t y o f the equipment,  the apparatus begins to o v e r l o a d amplitude.  As a r e s u l t ,  o f f and approach z e r o .  with  the a m p l i f i e r v o l t a g e  zero.  and the f l u c t u a t i o n s of the pan reduce i n  the standard  fall  voltage  d e v i a t i o n s of the s i g n a l s are seen to  When the equipment i s completely  overloaded,  always exceeding the 10V maximum sampling  of the Tecmar d a t a l o g g i n g  board, the standard  d e v i a t i o n would be  The s o l i d s c i r c u l a t i o n r a t e s a t which the maximum  d e v i a t i o n s occur  For  decrease w i t h  decreasing  standard  pan angle and occur  at lower  c i r c u l a t i o n r a t e s when sand i s the bed m a t e r i a l .  3.3.4  Response o f the Impact Flowmeter to B u t t e r y f l y Valve and Stoppage of S o l i d s C i r c u l a t i o n  Changes i n the o p e r a t i o n the b u t t e r f l y v a l v e  Closure  of the CFB u n i t as a r e s u l t of the c l o s u r e o f  c o u l d not be d e t e c t e d  by the impact flowmeter.  i n s e n s i t i v i t y was noted f o r a l l t h r e e pan angles  and both s o l i d s .  This The l a c k  of s e n s i t i v i t y of the impact flowmeter a r i s e s from the nature of the load beam s i g n a l , the long sampling times r e q u i r e d s i g n a l when u s i n g  t h i s method and the i n a c c u r a c i e s a s s o c i a t e d w i t h  measurement t e c h n i q u e . effect  to o b t a i n a r e p r e s e n t a t i v e  The f l u c t u a t i n g l o a d beam s i g n a l d i d not enable the  o f the b u t t e r f l y v a l v e c l o s u r e to be e a s i l y observed.  representaive calculate  average v o l t a g e ,  the a v e r a g e s .  this  sampling p e r i o d s  As a r e s u l t ,  To o b t a i n a  of 1 minutes were used to  the equipment c o u l d not measure  r a p i d l y changing average s i g n a l s t r e n g t h s .  A d d i t i o n a l l y , the i n a c c u r a c i e s  of t h i s measurement technique made i t i m p o s s i b l e  to determine whether a  -89-  change i n the e f f e c t i v e  force represented  a response  to the b u t t e r f l y  c l o s u r e or was the r e s u l t of n o i s e In the e x p e r i m e n t a l The  impact  valve  measurement.  flowmeter was not a b l e to measure the t r a n s i e n t  response of  the f l o w r a t e of s o l i d s out of the f a s t bed r e s u l t i n g from a change i n solids  f e e d r a t e to the upflow column.  The meters i n s e n s i t i v l t y  from the problems o u t l i n e d i n the p r e v i o u s paragraph. l o a d beam s i g n a l  t r a c e showed the o s c i l l a t i o n s  resulted  Observation  to decrease  of the  i n magnitude and  frequency  over a p e r i o d of time when the s o l i d s c i r c u l a t i o n r a t e was  stopped.  The p e r i o d o f decay was found  to Increase w i t h i n c r e a s e d  hold-up i n the f a s t bed and w i t h decreased  f a s t bed gas v e l o c i t y .  u s e f u l n e s s of these o b s e r v a t i o n s Is l i m i t e d  The  The  s i n c e the decay r a t e s c o u l d not  be q u a n t i f i e d and the decay time c o u l d not be a c c u r a t e l y  3.4  solids  determined.  M o d i f i e d O r i f i c e R e s u l t s and D i s c u s s i o n  modified o r i f i c e ,  as s t u d i e d (see s e c t i o n 2.3), was not a b l e to  p r o v i d e a s i g n a l from which the s o l i d s c i r c u l a t i o n r a t e c o u l d e a s i l y be determined. orifice  Initial  s t u d i e s with  to tube diameter  f u n n e l apparatus,  the 45° m o d i f i e d o r i f i c e , u s i n g an  r a t i o of 0.5, w i t h the s o l i d s being f e d by t h e  showed the change i n the p r e s s u r e d i f f e r e n t i a l  from the flow of s o l i d s  to be v e r y s m a l l , and a p p r o x i m a t e l y  magnitude to the zero d r i f t  resulting  equal i n  of the p r e s s u r e t r a n s d u c e r , F i g u r e 3.23a.  As a  r e s u l t , i t was not p o s s i b l e to determine p r e s s u r e d i f f e r e n t i a l s .  I n the  case of s o l i d s being f e d by the secondary  orifice  apparatus,  c y c l o n e to the m o d i f i e d  f o r the same o r i f i c e and o r i f i c e diameter  as b e f o r e , the  p r e s s u r e d i f f e r e n t i a l was found  to vary w i l d l y , w i t h p r e s s u r e  up t o 25 mm H 0 , F i g u r e 3.23b.  Due to the l a r g e magnitude of the  2  fluctuations  -90-  B  F i g u r e 3.23  E f f e c t of s o l i d s f l u x on m o d i f i e d o r i f i c e p r e s s u r e differential. A) Alumina f e d by f u n n e l , G = 25 kg/m s based on the o r i f i c e tube c r o s s - s e c t i o n a l a r e a , U = 0.014 m/s. B) Sand f e d by secondary c y c l o n e , G = 22 kg/m s based on the o r i f i c e tube c r o s s - s e c t i o n a l a r e a , U = 0.024 m/s. 2  s  Q  2  s  0  -91-  f l u c t u a t l o n s , i t was  not p o s s i b l e  to d e t e c t an apparent  change In the  p r e s s u r e d i f f e r e n t i a l as a r e s u l t of a change i n s o l i d s f l u x .  The  source of the o s c i l l a t i o n s was  may  have been caused through  not s t u d i e d i n d e t a i l , but they  by v a r i a t i o n s i n the s o l i d s and/or gas f l o w r a t e s  the a p p a r a t u s .  The  p o s s i b l e sources of s o l i d s f l o w r a t e  v a r i a t i o n s are d i s c u s s e d i n S e c t i o n 3.2. f l o w r a t e may secondary  have r e s u l t e d  from bubbles  The v a r i a t i o n s from  i n gas  the b u b b l i n g bed  s o l i d s r e t u r n l i n e a e r a t i o n tap t r a v e l l i n g up the  return line  to the o r i f i c e  To understand  why  and  solids  apparatus.  the m o d i f i e d o r i f i c e d i d not measure an  a p p r e c i a b l e change i n the p r e s s u r e d i f f e r e n t i a l between the o r i f i c e t h r o a t and upstream p r e s s u r e s w i t h changing  solids  flowrates, i t i s  n e c e s s a r y to review the p r i n c i p l e s which p r e d i c t o r i f i c e meter.  of an  A n a l y s i s of o r i f i c e meters and o t h e r c o n s t r i c t i o n  flowmeters  i s g e n e r a l l y based  negligible  frictional  f l o w i n g stream  the behaviour  remain  type  on B e r n o u l l i ' s theorem which, f o r  l o s s e s , r e q u i r e s that  the t o t a l head of a  constant, i . e . :  2 H = -— Pg  + Y_  2g  + y = constant }  This r e l a t i o n s h i p provides a b a s i s f o r determining response  of a f l u i d  undergoing  case, where the f l u i d  v  (3.4.1)  '  the p r e s s u r e  a change i n v e l o c i t y .  For the s i m p l e s t  i s i n c o m p r e s s i b l e , the f l o w i s n o n - t u r b u l e n t ,  f r i c t i o n a l head l o s s e s are s m a l l and e l e v a t i o n changes are the r e l a t i o n s h i p between v e l o c i t y and p r e s s u r e may  be  negligible,  expressed  as:  (P1-P2) = £  (V  2 2  2  - Vi )  (3.4.2)  -92-  In r e a l i t y , and  p a r t i c u l a r l y when d e a l i n g w i t h gases,  f r i c t i o n a l head l o s s e s cannot be i g n o r e d .  modelled  an o r i f i c e ,  apply.  i s expected  passed  behaviour effect  phase c o u n t e r - c u r r e n t flow of gas  d i f f e r e n t v e l o c i t y changes.  to a c c e l e r a t e r a p i d l y  through  of the gas  solids  the o r i f i c e .  No  However, t h i s  In the case of the  to the lower  the o r i f i c e .  should  still  t e r m i n a l v e l o c i t i e s , encounter  The  the  extent of  i n the upstream  The  p a r t i c l e s , moving  the upward f l o w i n g gas,  at or near  an i n c r e a s i n g upward gas v e l o c i t y as  e n t e r the c o n i c a l s e c t i o n of the m o d i f i e d o r i f i c e . t h e r e f o r e slow down when viewed from a f i x e d theorem a p p l i e s to the p a r t i c l e  The  upstream p r e s s u r e  upstream p r e s s u r e . the gas  to s o l i d  t a p s , w i t h the o r i f i c e  The  their  they  p a r t i c l e s must  p o i n t of r e f e r e n c e . flow, the decrease  If  in velocity  of the p a r t i c l e s should cause a p r e s s u r e d i f f e r e n t i a l between the and  this  result  p r e s s u r e being g r e a t e r than the o r i f i c e p r e s s u r e . c o u n t e r - c u r r e n t l y downward through  gas,  tube v e l o c i t y  doubt, the s o l i d s a f f e c t  through  two  to a h i g h e r t h r o a t v e l o c i t y as i t  to d e c e l e r a t e r a p i d l y  as i t passes  i s not known.  Bernoulli's  and  In a d d i t i o n , one must c o n s i d e r the problem of having  e n t e r s the o r i f i c e and having  This s i t u a t i o n i s often  the p r e v i o u s l y mentioned d e v i a t i o n s from the n o n - i d e a l  components undergoing the gas  compressible  term.  In the case of two  case  is  u s i n g a m o d i f i e d form of B e r n o u l l i ' s theorem which i n c o r p o r a t e s a  head l o s s  through  the f l u i d  orifice  p r e s s u r e being l a r g e r than  net change i n p r e s s u r e would depend on the r a t i o  the of  f l o w r a t e s , the magnitude of the v e l o c i t y change which each  -93-  component undergoes, as w e l l as the e f f e c t s l o s s e s and d e n s i t y changes. difficult  to c a l c u l a t e  Clearly  of turbulence,  t h i s net change i n p r e s s u r e  and would have to be determined  In the case o f c o u n t e r - c u r r e n t  f r i c t i o n a l head  g a s / s o l i d s flow,  experimentally.  the maximum gas  v e l o c i t y , which occurs  a t the p o i n t of maximum c o n s t r i c t i o n ,  t h r o a t of the o r i f i c e ,  should  the p a r t i c l e s being  studied.  probably  i s very  i . e . at the  not exceed the t e r m i n a l v e l o c i t y o f  I f an upward gas v e l o c i t y  i n excess of the  t e r m i n a l v e l o c i t y o f the s m a l l e s t p a r t i c l e s Is used, t h i s c o u l d r e s u l t i n the entrainment of some of the p a r t i c u l a t e  material.  problem would i n c r e a s e as the gas v e l o c i t y  Is i n c r e a s e d .  i n c r e a s i n g gas v e l o c i t y would depend on the s o l i d s f l u x e s the s o l i d s may behave i n a manner s i m i l a r  The s e v e r i t y  flux.  of t h i s  The response t o At h i g h  solids  to s o l i d s i n a CFB, where  the s o l i d s a r e observed to flow both c o - and c o u n t e r - c u r r e n t l y to the g a s . T h i s c o u l d l e a d to s l u g g i n g of gas and s o l i d s r e s u l t of s o l i d s accumulating The  gas  on the o r i f i c e .  low gas v e l o c i t i e s a r e probably  s e n s i t i v i t y of the m o d i f i e d  through the o r i f i c e as the  r e s p o n s i b l e f o r the l a c k o f  o r i f i c e meter i n the present  work.  The maximum  v e l o c i t i e s a t the t h r o a t o f the o r i f i c e d i d not exceed 0.24 m/s.  relatively  s m a l l change i n gas v e l o c i t i e s , ( c . f . C a r l s o n  with v e l o c i t y velocity  changes up to 44 m/s and F a r b a r  changes up to 55 m/s), p r o v i d e s  The  (1948) who worked  (1953) who used gas  one p o s s i b l e e x p l a n a t i o n of why  the o r i f i c e meter d i d not d e t e c t any n o t i c e a b l e changes i n p r e s s u r e d i f f e r e n t i a l as the s o l i d s c i r c u l a t i o n r a t e was changed.  -94-  3.5 The r e s u l t s are  L-Valve C a l i b r a t i o n  of the L - v a l v e c a l i b r a t i o n s  Results f o r alumina and Ottawa sand  shown i n F i g u r e s 3.24 and 3.25 and F i g u r e s 3.26 and 3.27  These f i g u r e s rate,  show the average p a r t i c l e v e l o c i t y  based on the f a s t bed c r o s s - s e c t i o n a l  through F i g u r e s 3.26 and 3.27 r e p r e s e n t fitted  the data u s i n g l e a s t  expected r e s u l t s  squares.  area.  respectively.  v s . the s o l i d s The s o l i d  the s t r a i g h t  circulation  l i n e s drawn  l i n e s which b e s t  The dashed l i n e s i n d i c a t e  assuming that the bulk d e n s i t y of the s o l i d s  the  flowing  through the L - v a l v e i s the same as the bulk d e n s i t y of the s o l i d s at minimum f l u i d i z a t i o n . Velocity  measurements were taken over a v a r i e t y  of o p e r a t i n g  c o n d i t i o n s , w i t h f a s t and slow bed v e l o c i t i e s between 1 and 5 m/s respectively  0.02  2  and  0.15 m/s  the  alumina and 40 kg/m s w i t h the Ottawa sand, based on the f a s t bed  c i r c u l a t i o n r a t e s up to 60 kg/m s w i t h  2  cross-sectional did  and s o l i d s  and  area.  I t was found that these v a r i a t i o n s  not have a d i s c e r n a b l e e f f e c t  with these ranges  on the p a r t i c l e v e l o c i t y  vs. solids  flux  relationship. F i g u r e s 3.24 and 3.25 i l l u s t r a t e position the  the e f f e c t  of measurement on p a r t i c l e v e l o c i t y .  of the  Each data p o i n t  average of up to f i v e measurements taken at each  position  and s e t of o p e r a t i n g c o n d i t i o n s .  This result  the r e l a t i o n s h i p  position  of G o l d b l a t t  s o l i d s moved through the v e r t i c a l s e c t i o n they neared  circumferential  used f o r measurement  between p a r t i c l e v e l o c i t y  agrees w i t h the f i n d i n g s  the c o r n e r of the L - v a l v e .  represents  F o r both the sand and the  alumina, I t appears t h a t the c i r c u m f e r e n t i a l does not a f f e c t  circumferential  and s o l i d s  (1985) who  observed  of an L - v a l v e l n plug flow  flux. that until  -95-  0.075  \  T  1  1  r  0.060  >O 0.045 O  > u  0.030 Position 1  o  A  I— < 0.015 Q_  •  Position 2  O  P o s i t i o n 3-  0  Position 4  O  Position 5  0.0  12  24  36  48  60  SOLIDS FLUX (kg/m s) 2  ure  3.24  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on average p a r t i c l e v e l o c i t y measured at d i f f e r e n t circumferential p o s i t i o n s f o r alumina, U = 0.014 m/s, Uf = 2.8 to 4.8 m/s. s  -96-  0.030  (0  E  0.024  >-  8  O 0.018 O  _l o  A  Position 1  •  Position 2  < 0.006 Q_  O  Position 3  0  Position 4  O  Position 5  \—  0.0  8  16  1  24  32  40  SOLIDS FLUX (kg/m s) z  ure  3.25  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l a r e a , on average p a r t i c l e v e l o c i t y measured a t d i f f e r e n t c i r c u m f e r e n t i a l p o s i t i o n s f o r sand, U = 0.024 m/s, U = 3.0 t o 6.0 m/s s  Q  -97-  0.075 i  i  0  |  12  i  |  24  i  |  i  |  36  48  i  60  SOLIDS FLUX (kg/m s) z  F i g u r e 3.26  E f f e c t of s o l i d s f l u x , based on the f a s t bed c r o s s - s e c t i o n a l area, on average p a r t i c l e v e l o c i t y f o r alumina, U = 0.014 m/s, Uf = 2.8 to 4.8 m/s. s  -98-  Figure  3.27  E f f e c t of s o l i d s f l u x , based on the f a s t bed area, on average p a r t i c l e v e l o c i t y f o r sand, U = 0.024 m/s, U = 3.0 to 6.0 m/s. s  f  cross-sectional  -99-  In F i g u r e s 3.26 and 3.27, p a r t i c l e v e l o c i t i e s have been determined by averaging  a l l o f the measurements, taken at the f i v e c i r c u m f e r e n t i a l  p o s i t i o n s , f o r each s e t of o p e r a t i n g c o n d i t i o n s . alumina and sand, show good agreement with  The r e s u l t s , f o r both  the best  fitted  l i n e s a t low  2  2  c i r c u l a t i o n r a t e s , l e s s than 24 kg/m s f o r alumina and 12 kg/m s f o r Ottawa sand. bed  T h i s i s not s u r p r i s i n g , s i n c e a t these  d i d not e x h i b i t choking  through the L - v a l v e .  c i r c u l a t i o n r a t e s , the f a s t  or s l u g g i n g and the s o l i d s moved smoothly  As c i r c u l a t i o n r a t e s were i n c r e a s e d , a s t i c k / s l i p  s o l i d s flow p a t t e r n developed i n the L - v a l v e , w i t h the d u r a t i o n of the p e r i o d s of s t i c k i n g circulation rate.  the l e n g t h of s l i p and  Increasing with i n c r e a s i n g  The development of the s t i c k / s l i p  flow p a t t e r n r e s u l t e d  i n l a r g e r d e v i a t i o n s between p a r t i c l e v e l o c i t y measurements f o r a g i v e n s e t of o p e r a t i n g  conditions.  Since  the s l i p  p e r i o d s were becoming l a r g e with residence  time i n the L - v a l v e ,  respect  l e n g t h and d u r a t i o n of s t i c k i n g to the o v e r a l l l e n g t h and the  the v e l o c i t y measurements were i n c r e a s i n g l y  a f f e c t e d by the behaviour of the s o l i d s when they entered zone. area,  I f the s o l i d s were to stop immediately on e n t e r i n g the measurement the p a r t i c l e v e l o c i t y was found to be lower than the mean p a r t i c l e  velocity.  On the other hand i f the s o l i d s were found to s l i p  or most of the measurement greater  than the average of the measured s o l i d v e l o c i t i e s .  circulation rates.  through a l l  zone, the s o l i d s v e l o c i t y was found to be  p a r t i a l l y accounts f o r the poorer higher  the measuring  agreement with  the best  This  probably  fitted  l i n e s at  A d d i t i o n a l l y , the i n a c c u r a c i e s of the b u t t e r f l y  v a l v e c i r c u l a t i o n r a t e measurements may have a l s o c o n t r i b u t e d  measurements  at higher  lines.  f l u x e s to the poorer  agreement w i t h  the best  fitted  -100-  If  the s o l i d s c i r c u l a t i o n r a t e i s zero i t i s apparent  p a r t i c l e v e l o c i t y i n the L - v a l v e should a l s o be z e r o . p a r t i c l e v e l o c i t y versus s o l i d s However,  f o r both  the alumina  l i n e s d i d not pass alumina  through  and  and sand  solids  the o r i g i n .  t h a t the best  fitted  intercept  This l i k e l y  arises  f o r the from  the p a r t i c l e v e l o c i t y measurements as d i s c u s s e d above  f l u x measurements v i a the b u t t e r f l y v a l u e  to be  significant.  The alumina  experimental  expected  through  i t was found  f o r the sand.  the h i g h e r s o l i d s c i r c u l a t i o n r a t e s . considered  Thus, the p l o t s of  the o r i g i n , but had a p o s i t i v e  and a n e g a t i v e i n t e r c e p t  i n a c c u r a c i e s i n both  f l u x should pass  that the  However,  the d e v i a t i o n s are not  r e s u l t s were found  r e s u l t s at c i r c u l a t i o n  rates less  (see S e c t i o n 3.22) at  to agree w e l l with the 2  than 24 kg/m s, F i g u r e 3.26.  At  2  r a t e s g r e a t e r than 24 kg/m s the d e v i a t i o n s between e x p e r i m e n t a l and expected  results  i n c r e a s e d , w i t h the expected  particle velocity.  r e s u l t s u n d e r e s t i m a t i n g the  The i n c r e a s e d d e v i a t i o n can be p a r t i a l l y a t t r i b u t e d to  the i n a c c u r a c i e s of the data at h i g h e r c i r c u l a t i o n r a t e s .  However,  it is  a l s o p o s s i b l e that the poorer agreement at h i g h e r c i r c u l a t i o n r a t e s a r i s e s from  the s o l i d s bulk d e n s i t y i n the L - v a l v e d e c r e a s i n g at the h i g h e r  rates. Comparison of the e x p e r i m e n t a l results  (see f i g u r e 3.27) shows the expected  underestimate fitted  results  the p a r t i c l e v e l o c i t y .  and expected  results  p r o b a b l y r e s u l t s from velocities  f o r sand with results  However,  l i n e s are s i m i l a r .  the expected  to always  the s l o p e s of the best The poorer agreement  i n a c c u r a c i e s i n the measurements of p a r t i c l e  and s o l i d s f l u x e s and i n the assumed bulk d e n s i t y .  -101-  3.6  Butterfly  3.6.1 During and  2.7)  the course  was  Valve  Introduction  of t h i s work, the b u t t e r f l y v a l v e  (see F i g u r e  found to p r o v i d e a simple method of measuring  circulation rates.  However, the b u t t e r f l y v a l v e was  solids  prone to  problems so t h a t the r e s u l t s of b u t t e r f l y v a l v e c i r c u l a t i o n measurements were not  3.6.2  stick  The  B u t t e r f l y Valve  Operating  v a l v e became m i s a l i g n e d  i n the c l o s e d p o s i t i o n .  w i t h use  the o p e r a t i o n of the and,  as a r e s u l t ,  butterfly  tended  to  i n t o the b e a r i n g s  s t i c k i n g , e r o s i o n and  of  f a t i g u e of  valve. To  and  rate  Difficulties  S o l i d s found t h e i r way  the rods of the b u t t e r f l y v a l v e , c a u s i n g the  frequent  always c o n s i s t e n t .  S e v e r a l problems were encountered w i t h valve:  2.1  c o r r e c t f o r misalignment, the b o l t s s e c u r i n g the v a l v e were removed  the s e c t i o n s of the column r e s t i n g on the v a l v e were l i f t e d  o f f so  that  then p o s i t i o n e d so  that  the v a l v e p o s i t i o n c o u l d be changed.  The  v a l v e was  it  The  o v e r l y i n g s e c t i o n s of the  d i d not  contact  the column w a l l s .  column were then lowered and The periodic  the s e c u r i n g b o l t s were  return  re-installed.  second, more s e r i o u s problem, r e q u i r e d removal of the v a l v e intervals  between the two which h e l d and  f o r maintenance.  T h i s problem arose  rods of the b u t t e r f l y v a l v e and a c t e d as b e a r i n g s  the aluminum rods and  f o r the r o d s .  at  from s o l i d s g e t t i n g  the p l e x i g l a s s f l a n g e s The  s o l i d s tended to g a l l  to erode the p l e x i g l a s s b e a r i n g  areas.  As a  result,  -102-  the movement of rods became d i f f i c u l t ,  and s o l i d s e v e n t u a l l y escaped the  column by f l o w i n g out through the b e a r i n g s . moving the rods, coupled  with  The i n c r e a s e d d i f f i c u l t y i n  the s t i c k i n g of the b u t t e r f l y v a l v e i n the  c l o s e d p o s i t i o n , l e d to s p l a y i n g of the gears used to s y n c h r o n i z e  the  movement of the two v a l v e p l a t e s and f a t i g u e of the l e v e r s and p o i n t s of attachment.  E v e n t u a l l y , the metal gave way.  3.6.3 The  E f f e c t of B u t t e r f l y Valve  Closure  impact flowmeter was not a b l e to d e t e c t any e f f e c t of c l o s i n g of  the b u t t e r f l y v a l v e , a t l e a s t  f o r p e r i o d s of 1 minute a f t e r the c l o s u r e .  However, comparison of the t r a c e of p r e s s u r e  drop a c r o s s  the b u t t e r f l y  v a l v e and accumulated s o l i d s of the f i r s t  c i r c u l a t i o n r a t e measurement at a  constant  the t r a c e s of the second and  s e t of o p e r a t i n g  conditions with  subsequent measurements, recorded  w i t h i n 4 minutes of the p r e v i o u s  measurement showed some d i f f e r e n c e s , F i g u r e s 3.28a and 3.28b. for  the f i r s t  operating other  c i r c u l a t i o n r a t e measurement taken a t a g i v e n s e t of  c o n d i t i o n s was a smooth, m o n i t o n i c a l l y i n c r e a s i n g c u r v e .  hand, the t r a c e s of the second and f o l l o w i n g c i r c u l a t i o n  measurements were not smoothly i n c r e a s i n g c u r v e s . drop was observed to i n c r e a s e , but w i t h d i f f e r e n c e s between the f i r s t operating  with  the case,  rate  the p r e s s u r e  superimposed f l u c t u a t i o n s .  and subsequent c u r v e s ,  The  taken a t constant  o n l y s m a l l v a r i a t i o n s i n the f a s t bed gas v e l o c i t y and  the f l o w r a t e of s o l i d s first  Instead,  On the  c o n d i t i o n s , were observed o n l y i f the CFB u n i t had been o p e r a t i n g  smoothly, i . e .  the  The t r a c e  through the v a l v e , f o r a t l e a s t  10 minutes p r i o r to  b u t t e r f l y v a l v e c i r c u l a t i o n r a t e measurement.  I f t h i s was not  the f i r s t  drop a c r o s s the  and f o l l o w i n g t r a c e s of the p r e s s u r e  -103-  c)  F i g u r e 3.28  t = 14 minutes  P r e s s u r e drop across the b u t t e r f l y v a l v e v e r s u s time f o r three s u c c e s s i v e c i r c u l a t i o n r a t e measurements.  -104-  butterfly  v a l v e d u r i n g c i r c u l a t i o n r a t e measurements were found  the f l u c t u a t i n g  i n c r e a s i n g curve type.  r a t e measurements was a p p r o x i m a t e l y  I f the time between c i r c u l a t i o n  10 minutes or more and the CFB u n i t  o p e r a t i n g smoothly, the p r e s s u r e drop curves f o r the f i r s t c i r c u l a t i o n r a t e measurements were a l l found increasing  During  and f o l l o w i n g  to be smooth and m o n i t o n i c a l l y  observed  with s h o r t i n t e r v a l s  between c l o s u r e s may  be an a r t i f a c t of the c i r c u l a t i o n r a t e measurement  the f i r s t  c i r c u l a t i o n r a t e measurement  s o l i d s may have seeped through collected  the d i s t r i b u t o r  plates,  the c o l l e c t e d  I f t h i s was  s o l i d s may have blocked holes on  thus causing the p r e s s u r e f l u c t u a t i o n s .  the s o l i d s  c i r c u l a t i o n was stopped  trapped between the screens and the p l a t e s . between the b u t t e r f l y  p l a t e s and  the case, d u r i n g  not be s u b s t a n t i a t e d by o b s e r v a t i o n s w h i l e the s o l i d s were However, a f t e r  technique.  of an e x p e r i m e n t a l run,  the h o l e s on the d i s t r i b u t o r  between the p l a t e s and the s c r e e n .  the f o l l o w i n g measurement,  T h i s could  circulating.  s o l i d s were found  The s o l i d s  v a l v e p l a t e s and screens a f t e r  c i r c u l a t i o n r a t e measurements s t a r t i n g c l o s u r e and ending were f i t t e d  10 seconds a f t e r  l i n e s using least  squares.  from  the v a l v e was opened. valve  the b u t t e r f l y  10 seconds b e f o r e the r e l e a s e of the accumulated  with s t r a i g h t  to be  s l o w l y flowed  The p r e s s u r e drop versus time data f o r s u c c e s s i v e b u t t e r f l y  fitted  was  c u r v e s , F i g u r e s 3.28a and 3.28c.  The f l u c t u a t i o n s actually  to be of  solids,  The s l o p e s of the  l i n e s f o r measurements taken w i t h i n 4 or 10 minutes of each other  were found  to be s i m i l a r  f o r the s u c c e s s i v e c i r c u l a t i o n r a t e measurements.  The s l o p e s of the l i n e s best f i t t i n g  the data of the second  and subsequent  c i r c u l a t i o n r a t e measurements were sometimes g r e a t e r and sometimes than the s l o p e of the l i n e best f i t t i n g  the data of the f i r s t  less  butterfly  -105-  v a l v e c i r c u l a t i o n r a t e measurement, with ±15%.  I t appears as i f the b u t t e r f l y  affect  the time averaged s o l i d s  the d i f f e r e n c e s t y p i c a l l y  being  v a l v e c l o s u r e does not s i g n i f i c a n t l y  c i r c u l a t i o n but does a f f e c t  Instantaneous  c i r c u l a t i o n r a t e s f o r s u c c e s s i v e measurements taken w i t h i n 4 minutes of each o t h e r .  I t a l s o appears that the s o l i d s ' c i r c u l a t i o n r a t e v a r i e s  n a t u r a l l y with  time, s i n c e the slopes of the l i n e s best  smoothly i n c r e a s i n g p r e s s u r e were a l s o found to v a r y seemed  to vary with  fitting  data  of measurements taken 10 minutes  t y p i c a l l y by ± 15%.  time, i t was decided  the p r e s s u r e  c a l c u l a t e the s o l i d s  data flux.  the p a r t i c l e v e l o c i t y  of the f i r s t  Since  the c i r c u l a t i o n  T h i s measurement was taken immediately  and impact flowmeter d e t e r m i n a t i o n s  and thus  after should  f l u x d u r i n g the  period. butterfly  r a t e measurement  ( e . g . F i g u r e 3.28a) g i v e s no i n d i c a t i o n  of the b u t t e r f l y  valve a f f e c t s  the CFB u n i t , at l e a s t  i n which measurements were taken.  butterfly  v a l v e c l o s u r e does not p e r t u r b  periods.  However, p e r t u r b a t i o n s  dumping of the s o l i d s of these  rate  c i r c u l a t i o n r a t e measurement to  The appearance of the t r a c e of the f i r s t  periods  apart  to use the slope of the l i n e  g i v e a b e t t e r r e p r e s e n t a t i o n of the a c t u a l s o l i d s data-taking  f i t t i n g the  perturbations  Therefore,  valve  circulation  that the c l o s u r e  during  the 1 minute  i t seems that the  the CFB u n i t , at l e a s t  appear to r e s u l t  over b r i e f  from the subsequent  accumulated d u r i n g a measurement.  The exact  sources  f o l l o w i n g a p r e v i o u s measurement are unknown.  One  p o s s i b l e cause i s that the opening of the v a l v e and r e l e a s e of the accumulated  solids  upsets  the f l o w r a t e s of gas i n the CFB.  explanation  i s that the dumping of accumulated s o l i d s  reinjection  of s o l i d s  i n t o the f a s t bed.  An a l t e r n a t i v e  a f f e c t s the  -106-  During measured by  o p e r a t i o n , the p r e s s u r e  drop a c r o s s  the p r e s s u r e  and  S6015, c h a r t r e c o r d e r .  transducer The  pressure  recorded  drop was  1 to 2 c y c l e s / m i n . with a superimposed 1.5 the b u t t e r f l y v a l v e and  Hz  minute a f t e r drop a c r o s s closure.  the s o l i d s  found  model  to o s c i l l a t e s l o w l y at  fluctuation.  drop a c r o s s  l o a d i n g of the f a s t bed  the b u t t e r f l y v a l v e c l o s u r e . the f a s t bed  on an E s t e r l i n e ,  was  The  c l o s u r e of  dumping of the s o l i d s accumulated on the v a l v e d i d  not cause a d e t e c t a b l e change i n the p r e s s u r e correspondingly,  the upflow column  d i d not  The  the bed,  f o r p e r i o d s up  oscillations in  seem to be a f f e c t e d  by  or to 1  pressure  the b u t t e r f l y  valve  -107-  4.0 The  b u t t e r f l y v a l v e , impact flowmeter and p a r t i c l e v e l o c i t y i n the  vertical  s e c t i o n of the L - v a l v e  c i r c u l a t i o n r a t e i n a CFB u n i t . meter, a t l e a s t solids  Conclusion  c o u l d a l l be used to determine the s o l i d On the o t h e r hand, the m o d i f i e d  i n the form s t u d i e d , was not able to d e t e c t  f l o w i n g c o u n t e r - c u r r e n t l y to a g a s .  orifice  the movement of  The key c o n c l u s i o n s f o r  each c i r c u l a t i o n r a t e measurement method are summarized i n the f o l l o w i n g paragraphs. The  b u t t e r f l y v a l v e was found to p r o v i d e  measuring s o l i d s c i r c u l a t i o n r a t e s . the p r e s s u r e Successive  data  once the p r e s s u r e  measurements, a t constant  v a r y by ± 15%.  the s i m p l e s t method of  S o l i d s f l u x was e a s i l y determined transducer operating  had been c a l i b r a t e d . c o n d i t i o n s , were found t o  However, the b u t t e r f l y v a l v e i t s e l f was not dependable, as  a r e s u l t of s t i c k i n g ,  e r o s i o n and breakage.  Frequent maintenance of the  b u t t e r f l y v a l v e was r e q u i r e d to a l l o w continued  operation.  i n the o p e r a t i o n of the CFB u n i t were a l s o d e t e c t e d b u t t e r f l y valve. preceding  smooth o p e r a t i o n .  10 minutes p r i o r  across  the v a l v e with Traces  continuously  to the measurement, the change i n p r e s s u r e  f o r at  drop  time f o l l o w e d a smooth, m o n i t o n i c a l l y i n c r e a s i n g r a t e measurements, taken a f t e r  p e r i o d s of o p e r a t i o n , were i n c r e a s i n g curves  be  when u s i n g the  I f the system had operated  of the succeeding  showing d i s t i n c t  Perturbations  I t was found that t r a c e s depended on the d u r a t i o n of the  least  curve.  from  fluctuations.  The source  with  similar  of these  shorter  s l o p e s but  d i f f e r e n c e s appeared to  the dumping of the s o l i d s accumulated on the b u t t e r f l y v a l v e  affecting  the gas flow p a t t e r n i n the CFB u n i t and s o l i d s r e i n j e c t i o n to the upflow column.  -108-  Th e Impact flowmeter was found to respond to changes In the s o l i d s circulation rate. limitations: at  However, the equipment was found to have i n h e r e n t  The meter was not a b l e to sense changes i n s o l i d s  low c i r c u l a t i o n r a t e s .  restricted  The s e n s i t i v e  flowrate  range of the equipment was  to a narrow range of c i r c u l a t i o n r a t e s .  The geometry of the  equipment, coupled w i t h the d a t a l o g g i n g system employed, r e s u l t e d magnitude of the e f f e c t i v e r a t e s much l e s s the  f o r c e r e a c h i n g an upper l i m i t 2  than the d e s i r e d maximum of 100 kg/m s.  at c i r c u l a t i o n The response of  meter was o s c i l l a t o r y , w i t h the frequency and amplitude of the  fluctuations particulate  being a f f e c t e d material.  by the s o l i d s  To c a l c u l a t e  c i r c u l a t i o n rate,  pan angle and  the average v a l u e of the pan's  response, i t was n e c e s s a r y to I n t e g r a t e the load beam s i g n a l s up  In the  to 1 minute b e f o r e the time-averaged s i g n a l  consistent at I d e n t i c a l also  be c a l i b r a t e d ,  flowmeter r e s u l t s .  operating conditions.  introducing further The e f f e c t s  v a l u e s were found to be The impact flowmeter must  inaccuracies  into  the impact  of these problems r e s t r i c t e d  I t was l i m i t e d  f o r periods  of  the impact flowmeter.  of  c i r c u l a t i o n r a t e s and i n t h i s range, the r e s u l t s  the u s e f u l n e s s  to o p e r a t i n g over a narrow range showed c o n s i d e r a b l e  scatter. Particle velocity be  In the v e r t i c a l s e c t i o n  the s i m p l e s t and most r e l i a b l e s o l i d s  c i r c u l a t i o n r a t e measurement  t e c h n i q u e once the equipment was c a l i b r a t e d . e a s i l y measured. the  of the L - v a l v e was found to  P a r t i c l e v e l o c i t i e s were  Only the presence of i d e n t i f i a b l e p a r t i c l e s  s o l i d s was r e q u i r e d .  The c i r c u m f e r e n t i a l  position  flowing  of v e l o c i t y  with  -109-  measurement d i d not a f f e c t  the magnitude of the v e l o c i t i e s .  r e l a t i o n s h i p between p a r t i c l e v e l o c i t y and r e a s o n a b l y agree w i t h a s t r a i g h t f o r both alumina line.  and  line  sand were found  T h i s probably r e s u l t e d  from  s o l i d s f l u x was  fitted  by l e a s t  The found  squares.  to The  data  to be s c a t t e r e d about the best f i t  i n a c c u r a c i e s i n measuring s o l i d s  fluxes.  At low c i r c u l a t i o n r a t e s , the agreement between the e x p e r i m e n t a l data the l i n e b e s t f i t t i n g  the data was  good.  However, w i t h  increasing  c i r c u l a t i o n r a t e the agreement of the data w i t h the best f i t t e d poorer.  The  poorer agreement r e s u l t e d  s l i p p i n g of the s o l i d s f l o w i n g through circulation rates. disadvantages  from  T h i s method s u f f e r e d  l i n e became  the Increase of s t i c k i n g  the L - v a l v e w i t h  the p r e v i o u s l y mentioned  to be underestimated  bulk d e n s i t i e s of the s o l i d s  and  increasing  of r e q u i r i n g c a l i b r a t i o n u s i n g the b u t t e r f l y v a l v e .  v e l o c i t i e s were found  and  Particle  when c a l c u l a t e d , assuming  the  i n the L - v a l v e were the same as a t minimum  fluidization. The  f a i l u r e of the m o d i f i e d o r i f i c e  rates resulted  from  i n measuring s o l i d  circulation  the s m a l l v e l o c i t y changes which the gas and  e x p e r i e n c e d w h i l e p a s s i n g through  the o r i f i c e .  changes were l e s s  As a r e s u l t ,  than 0.24  m/s.  T y p i c a l l y , the  velocity  the c o r r e s p o n d i n g  d i f f e r e n t i a l s a c r o s s the o r i f i c e were too s m a l l to be d e t e c t e d by p r e s s u r e t r a n s d u c e r and  the e f f e c t s of changing  c o u l d not be measured.  Use  technique appears  pressure the  solids c i r c u l a t i o n rates  of t h i s technique would appear to demand  c o n s i d e r a b l e c o n s t r i c t i o n of the r e t u r n l i n e , Hence t h i s  solids  l e a d i n g to r i s k s of b r i d g i n g .  to be u n s u i t a b l e f o r c i r c u l a t i n g bed  systems.  -110-  lt  does not appear that any of these meters are i d e a l l y  i n a h i g h temperature and/or p r e s s u r e CFB. breakage and i s d i f f i c u l t was  to o p e r a t e .  f o r use  v a l v e i s prone to  The impact flowmeter, as s t u d i e d ,  not able to a c c u r a t e l y measure s o l i d s  measurements, would be d i f f i c u l t  The b u t t e r f l y  suited  flux.  i n an i n d u s t r i a l  Particle CFB.  velocity  -111-  5.0 A new  b u t t e r f l y valve  solids circulation rates. v a l v e c l o s u r e and accumulation covering  Recommendations  should The  sticking,  new  be designed  v a l v e should  using  The  the p r e v i o u s  geometry, b e a r i n g  re-designed  respectively.  flowmeter should  new  v a l v e should  and  The  be decreased  l e v e r p i v o t should  impact flowmeter should r e s i s t a n c e to movement.  be  Increased  accomplished  dashpot l i q u i d .  s t i c k i n g and  be  signal  impact  range of the  equipment  be i n c r e a s e d .  The  b e a r i n g of  the  less  T h i s would i n c r e a s e the s e n s i t i v i t y of the meter  i n f o u r ways:  The  dampening e f f e c t of the dashpot  A more v i s c o u s f l u i d  to displacement  i s greater.  This  can be used as  A l a r g e r p i s t o n - t o - c y l i n d e r r a t i o would i n c r e a s e  connection  data  valve.  be r e p l a c e d by a b e a r i n g which o f f e r s  diameter of the p i s t o n and The  seen i n the pressure  to reduce the l o a d beam s i g n a l f l u c t u a t i o n s .  r e s i s t a n c e of the f l u i d  fluid.  screen  the d i s t a n c e between the load beam/lever  solids circulation rates. be  exist,  e f f e c t i v e m u l t i p l i e r of the  contact  p o i n t and  solids  be used to i n v e s t i g a t e the  so that the o p e r a t i n g  this,  the  and  dashpot of the impact flowmeter should  To do  should  still  butterfly  can be extended.  low  e l i m i n a t e the problems of  to e l i m i n a t e the problems of o v e r l o a d i n g ,  fluctuations  at  f o r measuring  s o l i d s e r o s i o n of the v a l v e b e a r i n g s  causes of the p e r t u r b a t i o n s , i f they  The  built  between the v a l v e s d i s t r i b u t o r p l a t e ( s ) and  the p l a t e ( s ) .  obtained  and  Increasing  the the  the  c y l i n d e r would i n c r e a s e the volume of d i s p l a c e d  of the p i s t o n rod  to the l e v e r c o u l d be moved a  g r e a t e r d i s t a n c e from the l e v e r p i v o t so that the p i s t o n t r a v e l i s increased,  thus i n c r e a s i n g  can  the f l u i d  displacement  and  dampening f o r c e .  -112-  Regardless  of whether any  flowmeter should be s o l i d s , with  s t u d i e d u s i n g a v a r i e t y of d i f f e r e n t  the average p a r t i c l e diameter  being v a r i e d i n d e p e n d e n t l y . modelled  of these changes are made, the  The  results,  so that the f o r c e versus  predicted empirically, a l s o be c a r r i e d distribute  and  on  based o n l y on the p a r t i c l e p r o p e r t i e s .  out to o p t i m i z e  the b a f f l e and  the flow of s o l i d s e x i t i n g  T h i s may  The m o d i f i e d  p a r t i c l e density  i n v o l v e both  orifice  then  c i r c u l a t i o n r a t e r e l a t i o n s h i p can  screen designs  be be  Work should and  to  the c y c l o n e so t h a t the movement of  flowmeter pans should be r e b u i l t  the pan.  circulating  i f c o n s i s t e n t , should  s o l i d s past the flowmeter i s more d i s p e r s e d and impact  apparent  impact  steady.  Finally,  to e l i m i n a t e accumulation  pan m a t e r i a l and  the of  solids  geometry changes.  does not appear to o f f e r any  potential for  measuring the f l o w r a t e of s o l i d s moving c o u n t e r - c u r r e n t l y to a flow of and  thus, continued  not be undertaken. solids  f a s t bed that  i n v e s t i g a t i o n under these o p e r a t i n g c o n d i t i o n s should However, the a b i l i t y  of the m o d i f i e d o r i f i c e  f l o w r a t e s i n a c o - c u r r e n t g a s / s o l i d s stream  investigation.  gas  Such a meter c o u l d be i n s t a l l e d  to the primary  cyclone.  the m o d i f i e d o r i f i c e may  solids circulation rates.  to measure  i s worthy of  i n the l i n e connecting  the  Under these c o n d i t i o n s , i t i s p o s s i b l e  p r o v i d e an e f f e c t i v e method of measuring  CFB  -113-  Nomenclature  F(t) ^^ f i  E f f e c t i v e force - 2  instant F  g f  £  (MLT )  Time averaged  F(t)  of p a r t i c l e s i m p a c t i n g on the pan a t any  Force f e l t  e f f e c t i v e force  by the load  -2  over a time p e r i o d  At ( M L T ) - 2  beam a t any i n s t a n t  (MLT )  Lt  F(t) . >P1  F o r c e caused by the i ' *  p a r t i c l e Impacting on the pan at any  - 2  instant  (MLT )  g  Acceleration  Gs  Solids - 2  1  due to g r a v i t y  (LT  - 2  )  f l u x based on the f a s t bed c r o s s - s e c t i o n a l  area  1  (ML T- ) H  T o t a l head of f l o w i n g  P  S t a t i c pressure  (ML  fluid - 1  T  - 2  (L)  ) - 1  2  P  x  S t a t i c p r e s s u r e of the f l u i d  at p o s i t i o n 1  (ML T" )  P  2  S t a t i c p r e s s u r e of the f l u i d  at p o s i t i o n 2  (ML  t  Time (T) Upflow column s u p e r f i c i a l gas v e l o c i t y  U  O r i f i c e tube s u p e r f i c i a l gas v e l o c i t y  Q  U  Return column s u p e r f i c i a l gas v e l o c i t y  (LT (LT  - 1  (LT  6  V  A b s o l u t e v e l o c i t y of the f l o w i n g  f l u i d (L)  V  V e l o c i t y of the f l u i d  at p o s i t i o n 1  (LT  - 1  I  )  V  V e l o c i t y of the f l u i d  at p o s i t i o n 2  (LT  - 1  2  )  - 1  )  ) - 1  )  - 1  T  - 2  )  -114-  X £j g  Distance  from the l e v e r p i v o t p o i n t  to the p o i n t a t which  the e f f e c t i v e f o r c e a c t s ( L ) X^  Distance contact  Xp^  Distance pan  from the l e v e r p i v o t p o i n t  to the l o a d beam  point (L) from the i m p a c t i o n p o i n t of the i  ^ p a r t i c l e on the  t o the l e v e r p i v o t (L)  y  V e r t i c a l height  coordinate  (L)  At  Time p e r i o d over which the load beam s i g n a l was averaged (T)  p  Density  of the f l u i d  - 3  (ML )  References  Anonymous, B a t t e l l e ' s M u l t i s o l i d F l u i d i z e d - B e d Combustion to B a t t e l l e Development C o r p o r a t i o n , 1-18 (1981).  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I I , K e a i r n s , D.L. ed., Hemisphere P u b l i s h i n g C o r p o r a t i o n , Washington, D.C., 231-237 (1976). Beer, J.M. and Sarofim, A.F., F l u i d i z e d Combustion - Research Needs, NSF Workshop, Paper presented at F l u i d i z a t i o n and F l u i d - P a r t i c l e System-Research Needs and P r i o r i t i e s , R e n s s e l a e r P o l y t e c h n i c I n s t . Troy, New York, 1-15 (1979). B i e r l , T.W., Gajdos, L . J . , M c l v e r , A.E. and McGovern, J . J . , S t u d i e s i n Support of R e c i r c u l a t i n g Bed Reactors f o r the P r o c e s s i n g of C o a l , C a r n e g i e - M e l l o n U n i v e r s i t y , 24-27, 52-58 (1980). Cankurt, N.T., Turner, D.H., Avidan, A.A. and Y e r u s h a l m i , J . , The T u r b u l e n t F l u i d i z e d Bed, Report f o r the C l e a n F u e l s I n s t i t u t e , 1-25 (1977). 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Engstrom, F., Development and Commercial O p e r a t i o n of a C i r c u l a t i n g F l u i d i z e d Bed Combustion System, Paper p r e s e n t e d at the 6th I n t e r n a t i o n a l F l u i d i z e d Bed Combustion Conference, A t l a n t a , G e o r g i a , V o l . I I , 616-621 (1980). F a r b a r , L., The V e n t u r i as a Meter f o r G a s - S o l i d s M i x t u r e s , T r a n s a c t i o n s of the ASME, 75, 943-951 (1953). F i t z g e r a l d , T., B u s h n e l l , D., Crane, S. and Yeong-Cheng S., Technolgoy, 38, 107-120 (1984).  Powder  Fusey, I . , A Novel C i r c u l a t i n g F l u i d i z e d Bed, M.A.Sc. T h e s i s , U n i v e r s i t y of B r i t i s h Columbia, Vancouver, B.C. (1985). G e l d a r t , D. and Abrahamsen, A.R., F l u i d i z a t i o n of F i n e Porous Powders, Recent Advances i n F l u i d i z a t i o n , AIChE Symposium S e r i e s , V o l . 77, No. 205, 160-165 (1981). G o l d b l a t t , W.,  U.B.C., p e r s o n a l communication  (1985).  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Performance of Two-Staged F l u i d i z e d Bed Combustion, E n v i r o n m e n t a l S c i e n c e and Technology, V o l . 14, No. 8, 960-965 (1980). X  H o r i o , M., T a k i , A., H s i e h , Y.S. and Much, I . , E l u t r i a t i o n and P a r t i c l e T r a n s p o r t Through the Freeboard of a G a s - S o l i d F l u i d i z e d Bed, i n " F l u i d i z a t i o n " , Grace, J.R. and Matsen, J.M. eds., 509-518 (1980). Hosny, N.M., F o r c e s on Tubes Immersed i n a F l u i d i z e d U n i v e r s i t y of B r i t i s h Columbia (1982).  Bed,  Ph.D.  Thesis,  Jones, 0., I n i t i a l O p e r a t i o n of Conoco's South Texas F l u i d i z e d Bed Combustor, Paper presented a t : 10th Energy Technology Conference & E x p o s i t i o n , Washington, D.C., 1-13, (1983).  -117-  Knowlton, T.M. and H i r s a n , I . , L - V a l v e s C h a r a c t e r i z e d f o r S o l i d s Hydrocarbon P r o c e s s i n g , 3_, 149-156 (1978).  Flow,  Knowlton, T.M. and H i r s a n , I . , S o l i d s Flow C o n t r o l Using a Non-Mechanical L - V a l v e , Paper Presented at the 9th S y n t h e t i c Gas Symposium, Chicago, I l l i n o i s , 1-36 (1977). Knowlton, T.M. and H i r s a n , I . , Wet and Dry Limestone Feeding u s i n g an L - V a l v e , Paper presented a t the 6th I n t e r n a t i o n a l Conference on F l u i d i z e d Bed Combustion, V o l . I I , A t l a n t a , G e o r g i a , 565-570 (1980). K u n i i , D. and L e v e n s p i e l , 0., Entrainment and E l u t r i a t i o n from F l u i d i z e d Beds, J o u r n . of Chem. Eng. Japan, V o l . 2, No. 1, 84-88 (1969). Lund, T., L u r g i C i r c u l a t i n g F l u i d Bed B o i l e r : I t s Design and O p e r a t i o n , The 7th I n t e r n a t i o n a l Conference on F l u i d i z e d Bed Combustion, V o l . I , P h i l a d e l p h i a , 38-46, (1982). Mann, U. and T u b i n o v i t c h , M., A Method f o r Measuring L o c a l P a r t i c l e Flow Rates i n F l u i d i z e d Beds, Paper p r e s e n t e d a t the 75th Annual AIChE Meeting, Los A n g e l e s , C a l i f o r n i a (1982). Oakes, E . J . , Jave, J . and Engstrom, F., S t a r t u p and O p e r a t i n g E x p e r i e n c e a t the K a t t u a 22-MWe C o g e n e r a t i o n C i r c u l a t i n g F l u i d i z e d - B e d Combustion P l a n t , P r o c . of the Amer. Power Conf., V o l . 44, 64-68 (1982). O k i , K., Walawender, W.P. and Fan, L.T., The Measurement of L o c a l of S o l i d s P a r t i c l e s , Powder Technology, 18, 177-178 (1977).  Velocity  Reh,  L., F l u i d i z e d Bed P r o c e s s i n g , Chem. Eng. Prog., V o l . 67, No. 2, 58-63 (1971).  Reh,  L., L u r g i C o r p o r a t i o n , p e r s o n a l communication  (1984).  Rickman, W.S., H o l d e r , N.D. and Young, D.T., C i r c u l a t i n g Bed I n c i n e r a t i o n of Hazardous Wastes, Chem. Eng. Prog., V o l . 81, No. 3, 34-38 (1985). Sahagian, J . , Commercial Development of F l u i d i z e d Beds f o r D i r e c t Combustion of T a r Sands and Other O i l B e a r i n g M a t e r i a l s , Energy P r o g r e s s , V o l . 4, No. 1, 51-53 (1984). Sneyd, R.J., Energy Recovery from F l u i d i z e d Prog., V o l . 80, No. 1, 48-54 (1984). S t . John, B., A n a l y s i s and Comparison  Bed Combustion,  Chem. Eng.  of F i v e G e n e r i c FBC Systems.  T h e m e l i s , N.J. and Freeman, G.M., F l u i d J o u r n a l of M e t a l s , 52-57 (1984).  Bed Behavior i n Z i n c R o a s t e r s ,  -118-  Tomita, M., Hirama, T., A d a c h i , T. and Yamaguchi, H., Two-Stage F l u i d i z e d Bed Combustion of C o a l , Paper P r e s e n t e d at the 6th I n t e r n a t i o n a l F l u i d i z e d Bed Combustion Conference, A t l a n t a , G e o r g i a , V o l . I I , 623-631 (1980). van B r e u g e l , J.W., S t e i n , J.J.M. and d e V r i e s , R.J., I s o k i n e t i c Sampling i n a Dense G a s - S o l i d s Stream, P r o c . I n s t n . Mech. Engrs., V o l . 184, P t . 3C, 18-23 (1969/70). Y e r u s h a l m i , J . and Cankurt, N.T., F u r t h e r S t u d i e s of the Regimes o f F l u i d i z a t i o n , Powder Technology, 24, 187-205 (1979). Y e r u s h a l m i , J . and Cankurt, N.T., High V e l o c i t y F l u i d V o l . 8, No. 9, 564-571 (1978).  Beds, Chemtech.,  Y e r u s h a l m i , J . , Turner, D.H. and S q u i r e s , A.M., The F a s t F l u i d i z e d Bed, Ind. Eng. Chem. Process Des. Dev., V o l . 15, No. 1, 47-53 (1976).  -119-  Appendix A Computer Programs  -120-  Appendix A . l - D a t a l o g g i n g  Program  10  PRINT " T h i s program d a t a l o g s e i t h e r channel 0 or 1 of the Tecmar board"  20  PRINT "There are f a c i l i t i e s subtracted"  30  PRINT "from the data being l o g g e d . i n the"  40  PRINT "case where the equipment has not been c a l i b r a t e d but a"  50  PRINT "base v o l t a g e has been determined  60  PRINT "PRESS ANY KEY TO RUN THE PROGRAM"  70  X$=INPUT$(1)  80  CLS  90  REM $LINESIZE: 132 $PAGESIZE: 55  to i n p u t a base v o l t a g e which w i l l be  T h i s program Is designed  to be used  f o r each r u n ,  by some other means  100 WIDTH 80: CLS 110 DEFINT I,J,K,L,M 120 DIM A%(27000),L$(3) 130 DIG=0!: FSL=0!: PRES=0!: N0TE=0!: TOT=0: M=l 140 PRINT 150 PRINT "HARDWARE:  IBM p e r s o n a l computer,"  160 PRINT "Tecmar Lab Master A/D & D/A c o n v e r t e r , " 170 PRINT "(2 channel, 0 & 1, s i n g l e - e n d e d , g a i n = l , -10.V t o +10.V):" 180 PRINT "Channel 0 Hardware;" 190 PRINT "BLH 1 Kg Load Beam," 200 PRINT "Bofors s i g n a l a m p l i f i e r and c o n d i t i o n e r . " 210 PRINT "Channel 1 Hardware;" 220 PRINT " D i s a p r e s s u r e  transducer."  230 PRINT 240 INPUT "Enter the name of the f i l e  to be used  f o r data s t o r a g e :  ",FIL$  -121-  D a t a l o g g i n g Program - Continued 250 OPEN FIL$ AS #1 LEN=8 260 FIELD #1, 4 AS X$, 4 AS Y$ 270 IF N0TE=1 THEN GOTO 310 280 INPUT "Enter the i n v e s t i g a t o r s name: 290 INPUT "Enter the date:  ",NAM$  ",S$  300 IF NOTE=0! THEN GOTO 340 310 PRINT "Are the sampling  c o n d i t i o n s the same?"  320 I$=INPUT$(1) 330 IF I$="Y" OR I$="y" THEN GOTO 420 340 INPUT "Enter the l e n g t h of the sampling 350 INPUT "Enter the d e s i r e d sampling (1-30000)",S%  p e r i o d i n seconds:  ",T  rate i n points/second  360 NN%=T*S% 370 IF NN%<=27000 THEN GOTO 410 380 CLS:  PRINT: PRINT  390 PRINT "Choose a s m a l l e r sampling the two i s l e s s than 27000!" 400 CLS:  r a t e or p e r i o d such  GOTO 340  410 IF NOTE=0! THEN GOTO 450 420 PRINT "Are the o p e r a t i n g c o n d i t i o n s the same?" 430 I$=INPUT(1) 440 IF I$='Y" OR I$='y' THEN GOTO 590 450 INPUT "Base v o l t a g e ? " , VOL 460 CLS:  PRINT "Operating  Conditions:":PRINT  470 PRINT " F a s t bed c o n d i t i o n s " 480 INPUT " O r i f i c e diameter,  inches?",0D$  that the product o f  -122-  D a t a l o g g i n g Program -  Continued  490 INPUT " P r e s s u r e  upstream  of  the  orifice  meter,  cm o f  Hg?",UP$  500 INPUT " P r e s s u r e  drop across  the  orifice  meter,  cm o f  H 0?",PD$  510 P R I N T : 520 PRINT  2  PRINT "Slow  530 INPUT " S l o w  bed  conditions;"  bed f l u i d i z a t i o n  gas  flowrate,  540 INPUT " R o t a m e t e r  #1  Setting?",Rl$  550 INPUT " R o t a m e t e r  #2  Setting?",R2$  560 INPUT " R o t a m e t e r  #3  Setting?",R3$  570 INPUT " R o t a m e t e r  #4  Setting?",R4$  580 INPUT " R o t a m e t e r  #5  Setting?",R5$  590 LPRINT  rotameter  reading?",SB$  CHR$(27)"E":LPRINT  600 L P R I N T C H R $ ( 1 4 )  " I N V E S T I G A T O R : " T A B ( 2 0 ) NAM$  610 L P R I N T C H R $ ( 1 4 )  "DATA F I L E : " T A B ( 2 0 )  620 LPRINT C H R $ ( 1 4 )  " D A T E : " TAB(20)  630 LPRINT "  FIL$  S$  •  640 L P R I N T 650 LPRINT " B A S E V O L T A G E : " ; V O L 660 L P R I N T "BED C O N D I T I O N S : " : L P R I N T " F A S T B E D ; " 670 L P R I N T " O R I F I C E D I A M E T E R : " T A B ( 4 0 )  0D$;"in."  680 LPRINT "UPSTREAM P R E S S U R E : " T A B ( 4 0 )  U P $ ; " cm o f H g "  690 LPRINT "PRESSURE DROP ACROSS O R I F I C E : "  TAB(40)  P D $ ; " cm o f H 0 2  700 L P R I N T "SLOW B E D : " 710 L P R I N T " B U B B L I N G BED ROTAMETER R E A D I N G : " T A B ( 4 0 ) 720 L P R I N T "#1  ROTAMETER R E A D I N G : " T A B ( 4 0 )  Rl$  730 LPRINT "#2  ROTAMETER R E A D I N G : " T A B ( 4 0 )  R2$  SB$  -123-  D a t a l o g g i n g Program - Continued 740  LPRINT "#3 ROTAMETER READING:" TAB(40) R3$  750  LPRINT "#4 ROTAMETER READING:" TAB(40) R4$  760  LPRINT "#5 ROTAMETER READING:" TAB(40) R5$  770 LPRINT 780  LPRINT "SAMPLING RATE:";S%;" p o i n t s / s e c o n d "  790  LPRINT "SAMPLE LENGTH:",T;"  800  LPRINT "NUMBER OF DATA POINTS READ:";NN%: LPRINT: LPRINT  810  CLS: PRINT "Unit to be d a t a l o g g e d ,  seconds"  p r e s s u r e t r a n s d u c e r or load beam?"  820 V$=INPUT$(1) 830  IF V$="P" OR V$="p" THEN C%=1 ELSE C%=0  840  P%=0:IF S%>2000 THEN P%=0 P l o t  i f < 2000 p t s / s e c  850 CLS 860  CLS: PRINT "PRESS ANY KEY TO START DATA LOGGING."  870  I$=INKEY$:IF 1$="" THEN 870  880 CLS 890 F%=0 ' I n i t i a l i z e  overrun  flag  900  CALL TIMER(A%(1),F%,P%,NN%,C%,S%)  910  IF F%<>0 THEN PRINT " W a r n i n g — d a t a taken  920  IF F%<>0 THEN LPRINT: ";NN%: LPRI NT  930  PRINT "DATA LOGGING COMPLETE"  940  FOR 1-1 TO NN%  LPRINT "ACTUAL NUMBER OF DATA POINTS READ:  950 TIME=I/S% 960  IF A%(I)>32767 THEN  970  P=A%(I)/204.8-V0L  too f a s t ! " :NN%=NN%-F%  A%(I)=A%(I)-65535!  -124-  D a t a l o g g i n g Program -  Continued  980  LSET X$=MKS$(TIME):  990  PUT #1, I  LSET Y$=MKS$(P)  1000 NEXT 1010 CLOSE #1 1020 LPRINT CHR$(27)CHR$(12) 1030 CLS: PRINT "Do you want to take another  s e t of data?"  1040 I$=INPUT$(1) 1050 IF I$="Y" OR I$="y" THEN N0TE=1!" C=C%: 1060 STOP 1070 END  CLS: GOTO 240  -125-  Appendix A.2 - C l o c k S e t t i n g Program PAGE, 132 TITLE TIMER SUBROUTINE TO DO TIMED DATA COLLECTION FROM TECMAR A/D/A BOARD CALL FROM BASIC WITH CALL OF FORM: CALL TIMER (A%(1),F%,P%,N%,C%,S%) WHERE  A% IS ARRAY WHERE DATA ARE TO BE STORED F% IS OVERRUN FLAG—SET TO ZERO UPON NORMAL EXIT OTHERWISE SET TO VALUE OF CX REGISTER TO GIVE NUMBER OF POINTS NOT COLLECTED P% IS 0 TO OMIT REAL-TIME PLOT, OTHER TO PLOT N% IS NUMBER OF POINTS TO BE COLLECTED C% IS CHANNEL NUMBER OF A/D S% IS NUMBER OF DATA POINTS PER SECOND S% MUST BE < = SPEED OF A/D IF S% < 0 THAT MEANS WE WANT THAT MANY SEC/POINT  CSEG  SEGMENT ASSUME CS:CSEG, DS:NOTHING  TEMP  DW  ?  ;TEMP. STORAGE  PLOT  DW  ?  ;PLOT FLAG  TEMPSI DW  ?  ;TEMP. STORAGE FOR SI REGISTER  OVRUN  ?  ;OVERRUN OF A/D FLAG  DW  ;DEFINITIONS: ADDO  =1808  ; l / 0 ADDRESS OF TECMAR BOARD  ADD4  =ADD0+4  ;A/D CONTROL BYTE  -126-  Clock S e t t i n g Program - Continued ADD5  =ADD0+5  ;A/D CHANNEL NUMBER  ADD6  =ADD0+6  ;SOFTWARE START CONVERSION  ADD8  =ADD0+8  ;TIMER 9513 DATA PORT  ADD9  =ADD0+9  ;TIMER 9513 CONTROL PORT  PAGE  TIMER  PUBLIC  TIMER  PROC  FAR  PUSH  BP  -SAVE BP  MOV  BP.SP  ;SET BASE PARAMETER  MOV  DI,[BP]+6  ;GET DATA POINTS/SEC.  MOV  AX,[DI]  ;INTO BX REGISTER  MOV  BX.AX  MOV  DI,[BP]+8  ;GET CHANNEL NUMBER  MOV  AX,[DI]  ;AND STORE AS AX  MOV  DX,ADD5  ;AND OUTPUT TO A/D  OUT  DX,AL  ;(USE ONLY LOWER BYTE)  MOV  DI,[BP]+10  ;GET NUMBER OF DATA POINTS  MOV  CX,[DI]  ;STORE IN CX REGISTER  MOV  DI,[BP]+12  ;GET PLOT FLAG  MOV  AX,[DI]  ;STORE IN MEMORY  MOV  PLOT,AX  MOV  AL.128  MOV  DX.ADD4  ;EXTERN. START CONVERSION, ALL INTERRUPTS  OUT  DX,AL  ;GAIN=1)  MOV  AX,0  ;SI IS X-VALUE OF POINT TO BE  LIST  -127-  C l o c k S e t t i n g Program - Continued MOV  AX,6  INT  10H  MOV  DX.ADD6  IN  AL.DX  MOV  DX.ADD9  MOV  AL,23  OUT  DX,AL  MOV  DX.ADD8  ;SET UP HIGH RESOLUTION GRAPHICS MODE  ;RESET DONE FLIP-FLOP OF A/D  ;SET DATA POINTER TO MASTER MODE REGISTER  ;SET MASTER MODE REGISTER FOR SCALER CONTROL=  MOV  AL.23  OUT  DX,AL  MOV  DX.ADD8  ;SET MASTER MODE REGISTER FOR SCALER CONTROL=  MOV  AL,0  ;BCD DIVISION, ENABLE INCREMENT 8-BIT BUS,  OUT  DX.AL  ;FOUT ON, DIVIDE BY 16, SOURCE=Fl  MOV  AL.128  :COMPARATORS DISABLED, TOO DISABLED  OUT  DX,AL  MOV  DX.ADD9  ;SET DATA POINTER TO COUNTER MODE OF  MOV  AL,5  ;REGISTER 5  OUT  DX.AL  MOV  DX.ADD8  ;SET COUNTER 5 FOR COUNT REPETITIVELY,  MOV  AL,33  ;BINARY COUNT, COUNT DOWN, ACTIVE HIGH  OUT  DX.AL  ;TC, DISABLE SPECIAL GATE, RELOAD FROM LOAD,  CMP PAGE JL  BX,31  ;CHECK IF <31 POINTS/SEC  MED  ;IF SO JUMP  -128-  C l o c k S e t t i n g Program - Continued ;BRANCH TO HERE FOR 31 TO 20000 POINTS/SEC—USE 1 MHz FAST:  CLOCK  MOV  AL,11  ;C0UNT AT 1 MHz  (NO GATE, RISING  OUT  DX.AL  ;EDGE OF F l )  MOV  AX,10000  ;DIVIDE 1000000 BY PTS/SEC BY  MOV  DI.100  ;GETTING 10F6 INTO DX+AX  MUL  DI  DIV  BX  ;BX=PTS/SEC; RESULT IN DX+AX, BUT :IGNORE DX, SINCE DX=0  CMP  AX,200  ;DISABLE INTERRUPTS IF >=5000  JG  FAST2  ;POINTS/SEC  CLI FAST2: JMP  GO  ;BRANCH TO HERE FOR 1 TO 30 POINTS/SEC—USE 10kHz CLOCK MED:  MOV  AL.13  ;COUNT AT 10kHz (NOT GATE, RISING  OUT  DX,AL  ;EDGE OF F3)  MOV  AX,10000  ;CALCULATE NUMBER OF TICKS OF 10000 Hz CLOCK  CWD DIV  ;PER DATA POINT BY DIVIDING BX  ;10000 BY PTS/SEC  ;START CLOCK TICKING AT DESIRED RATE GO:  MOV  DX.ADD8  ;AND LOAD COUNTER 5 WITH TICKS  DEC  AX  ;(COUNT TO ZERO, DECREMENT AX)  OUT  DX,AL  ;FOR CORRECT COUNT)  MOV  AL,AH  OUT  DX,AL  ;8 BITS AT A TIME  MOV  DI,[BP]+14  ;GET OVERRUN FLAG ADDRESS  -129-  C l o c k S e t t i n g Program - Continued MOV  WORD PTR [DI],0 ;ZERO THE FLAG  MOV  OVRUN.DI  ;AND STORE THE FLAG ADDRESS  MOV  DI,[BP]+16  ;GET ADDRESS OF DATA ARRAY  MOV  DX,ADD9  ;LOAD COUNTER 5 FROM LOAD REGISTER  MOV  AL.112  ;AND ARM (START COUNTING)  OUT  DX,AL  MOV  DX.ADD4  ;ENABLE EXTERNAL START (PINES 3,4 OF  MOV  AL.132  ;J2 CONNECTOR MUST BE CONNECTED)  OUT  DX.AL  PAGE ;BEGIN DATA COLLECTION; COLLECT UPON EXTERNAL START TRIGGER DONE:  MOV  DX.ADD4  ;CHECK IF DATA READY  IN  AL.DX  CMP  AL.128  ;BY CHECKING READY BIT (BIT 7)  JB  DONE  ;LOOP UNTIL READY  TEST  AL.64  ;SEE IF DATA OVERRUN FLAG SET  JNE  ERRMESS  ;IF SO, NOTIFY BASIC PROGRAM AND EXIT  MOV  DX.ADD5  ;YES, DONE, SO GET LOW BYTE OF DATUM  IN  AL.DX  MOV  [DI],AL  ;AND STORE IT  INC  Dl  ;GO TO NEXT LOCATION IN ARRAY (1 BYTE LATER)  MOV  DX.ADD6  IN  AL.DX  MOV INC  [DI],AL Dl  ;GET HIGH BYTE AND STORE IT  -130-  C l o c k S e t t i n g Program - Continued CMP  PLOT.O  JZ  NOPLOT  ;DON'T PLOT IF PLOT FLAG=0  ;PLOT ROUTINE STARTS HERE MOV  TEMP.CX  ;SAVE CX FIRST  MOV  AH,AL  ;GET HIGH BYTE JUST TAKEN  MOV  ALJDI-2]  ;AND LOW BYTE FROM STORAGE SO AX=DATUM  ADD  AX,2047  ;CALCULATE Y-VALUE TO PLOT =  CWD  Ml:  ;199-((DATUM+2047)/21)  MOV  BX,21  DIV  BX  MOV  DX.AX  ;RESULT INTO DX  NEG  DX  ;NEGATE AND ADD TO 199  ADD  DX.199  MOV  SI.TEMPSI  ;GET X-VALUE OF LAST POINT ON SCREEN  INC  SI  ;G0 TO NEXT LOCATION ON SCREEN  CMP  SI,640  ;TEST IF AT RIGHT EDGE OF 640x200  JL  Ml  ;SCREEN  MOV  SI,0  ;IF SO, GO TO LEFT EDGE TO PLOT  MOV  CX.SI  ;GET X-VALUE INTO CX  MOV  TEMPSI.SI  ;SAVE X-VALUE  MOV  AX,3073  ;AH=12,AL=1 TO WRITE DOT TO SCREEN  INT  10H  ;PL0T POINT  MOV  CX.TEMP  ;RESTORE CX  DONE  ;DECREMENT CX AND LOOP IF > 0  NOPLOT: LOOP  ;DIVIDE BY 21—QUOTIENT IN AX  ;BRANCH TO HERE UPON FINISH OR OVERRUN  -131-  Clock S e t t i n g Program - Continued NOGO:  MOV  DX.ADD4  MOV  AL,0  OUT  DX.AL  STI  ;TURN OFF A/D  ;RESTORE INTERRUPT SERVICE  MOV  AX,2  INT  10H  POP  BP  ;RESTORE BP  RET  12  ;6 ARGUMENTS IN CALL X 2=12  DI.OVRUN  ;SET OVERRUN FLAG SINCE A/D GOING  ERRMESS: MOV MOV JMP TIMER  ENDP  CSEG  ENDS END  WORD PTR [DI],CX NOGO  ;TOO FAST  -132-  Appendix A.3 - I n t e g r a t i o n Program 10  LPRINT CHR$(27)"N"CHR$(10)  20  PRINT "Type of i n t e g r a t i o n d e s i r e d : "  30  PRINT "1) T r a p e z o i d a l "  40  PRINT "2) Simpson's"  50  PRINT "3) Both"  60  I$=INPUT$(1)  65  PTR=0  70  FLAG=2: CNT=1  80  IF I$="2" OR I$="S" THEN FLAG=1  90  IF I$="s" THEN FLAG=1  100  IF I $ = " l " OR I$="T" THEN FLAG=0  110  IF I$="t" THEN FLAG=0  120  CLS  130  INPUT "Data f i l e  140  TAG=0  150  PRINT: PRINT  160  INPUT " S t a r t i n g p o i n t of data to be read";ST#  170  ST=INT(STi?)  180  PRINT: PRINT  190  INPUT "Number of data p o i n t s  to be read";D$  to be i n t e g r a t e d  (odd numbered integer)";N#  200 N=N# 210  CLS  220  IF (2*INT(N#/2))ON# THEN GOTO 270  230  PRINT "*******"  240  PRINT "THE NUMBER OF DATA POINTS MUST BE AN ODD INTEGER"  250  PRINT "*******"  -133-  I n t e g r a t l o n Program - Continued 260 PRINT: PRINT: GOTO 190 270 OPEN D$ AS #1 LEN=8 280 FIELD #1, 4 AS X$, 4 AS Y$ 290 FIN=ST+N-1 300 GET #1,ST 310 XST=CVS(X$): YST=CVS(Y$) 320 GET #1,FIN 330 XFIN=CVS(X$): YFIN=CVS(Y$) 340 H=(XFIN-XST)/(N-1) 350 TSUM=0: SSUM=0: FL=0 360 FOR I=ST TO FIN 370 GET #1,1 380 X=CVS(X$) 390 Y=CVS(Y$) 400 IF FLAG=1 THEN GOTO 470 410 REM TRAPEZOIDAL  INTEGRATION  420 IF I=ST or I=FIN GOTO 430 ELSE GOTO 450 430  TSUM=TSUM+Y*H/2  440 GOTO 460 450 TSUM=TSUM+Y*H 460 IF FLAG=0 THEN 570 470 REM SIMPSON'S INTEGRATION 480 IF I=ST OR I=FIN THEN GOTO 490 ELSE GOTO 510 490  SSUM=SSUM+Y*H/3  500 GOTO 570  -134-  I n t e g r a t l o n Program -  Continued  510  550  520  IF  FL=1  THEN GOTO  SSUM=SSUM+4*Y*H/3  530  FL-1  540  GOTO  550  SSUM=SSTJM+2*Y*H/3  560  FL=0  570  NEXT  580  CLOSE  590  TAVG=TSUM/(XFIN-XST):  595  IF  PTR=1 THEN L P R I N T :  LPRINT:  600  IF  TAG=1 THEN L P R I N T :  GOTO  610  LPRINT:  620  LPRINT CHR$(14);"INTEGRATED  630  LPRINT:  640  LPRINT  650  LPRINT C H R $ ( 2 7 ) " - 1 "  660  LPRINT:  670  LPRINT C H R $ ( 2 7 ) " - 1 "  680  LPRINT " P o i n t s " ; S T ; " t h r o u g h " ; F I N ; " I n t e g r a t e d " :  690  GOTO  700  LPRINT:  710  IF  720  L P R I N T "The  integral  730  L P R I N T "The  average Y value over  740  LPRINT:  570  #1  LPRINT:  LPRINT:  SAVG=SSUM/(XFIN-XST) GOTO  640  660  LPRINT RESULTS"  LPRINT  CHR$(27);"E" "Data f i l e  name:  ";D$"  LPRINT  CHR$(27)"-0"  LPRINT "CASE";CNT:  LPRINT LPRINT  700 LPRINT  FLAG=0 THEN GOTO  LPRINT:  750 by S i m p s o n ' s m e t h o d the  is";SSUM  interval  is";SAVG  CHR$(27)"-0  -135-  I n t e g r a t l o n Program - Continued 750  IF FLAG=1 THEN GOTO 780  760 LPRINT "The I n t e g r a l by the T r a p e z o i d method is";TSUM 770 LPRINT "The average Y v a l u e over the i n t e r v a l 780  PRINT "Do you want to i n t e g r a t e another  is";TAVG  s e t of data from t h i s  file?"  790 Y$=INPUT$(1) 800  IF Y$="Y" OR Y$="y" THEN GOTO 150  TAG=1:CNT=CNT+1:PRINT:PRINT:LPRINT:LPRINT:  820 CLS 830  PRINT "Do you want to I n t e g r a t e data from another  840 ANS$=INPUT$(1) 850  IF ANS$="Y" OR ANS$="y" THEN PTR=1: GOTO 120  855  LPRINT CHR$(27)CHR$(12)  860  STOP  870  END  file?"  -136-  Appendix A.4 - Standard D e v i a t i o n Program 10  LPRINT: LPRINT: LPRINT: LPRINT CHR$(27);"E"  20  N=5801 '  30  ST=100  40  LPRINT CHR$(14); "VARIANCE RESULTS"  50  LPRINT: LPRINT  60  INPUT "Data f i l e  70  PRINT  80  INPUT "Mean Value";MEAN  90  PRINT: PRINT  to be read";D$  100 CLS 110 T0T=1 120 CNT=1 130 OPEN D$ AS #1 LEN=8 140 FIELD #1, 4 AS X$, 4 AS Y$ 150 SUM=0 160 FIN=ST+N-1 170 FOR I=ST TO FIN 180 GET #1, I 190 Y+CVS(Y$) 200 DIF=ABS(Y-MEAN) 210 SUM=SUM+DIF 2 220 IF(CNT=100) THEN PRINT (T0T*100) TAB(7) "POINTS ANALYSED": T0T=T0T+1: CNT=1 230 CNT=CNT+1 240 NEXT  -137-  Standard D e v i a t i o n Program - Continued 250  CLOSE #1  260  SDEV=SQR(SUM/(N-1))  270 LPRINT " F I L E : " TAB(7) D$ (TAB)15 "MEAN:" TAB(23) MEAN TAB(35) "STANDARD DEVIATION:" TAB(47) SDEV 280 CLS 290  INPUT "Next  300  IF D$="N" OR D$="n" THEN STOP  310  PRINT  320 GOTO 80 330  STOP  340 END  file":D$  -138-  Appendix A.5 - L i n e a r R e g r e s s i o n 10  LPRINT: LPRINT: LPRINT: LPRINT CHR$(27);"E"  20  LPRINT CHR$(14); "LINEAR REGRESSION  30  LPRINT: LPRINT  40  LPRINT CHR$(27)"N"CHR$(10)  50  INPUT "Data f i l e  60  LPRINT: LPRINT: LPRINT "FILE:";D$  70  TAG=0!  80  PRINT: PRINT  90  CLS  RESULTS"  to be read";D$  100 INPUT " S t a r t i n g p o i n t of the data  to be read";ST  110 PRINT: PRINT 120 INPUT "Number of data  points  to be f i t " ; N  130 CLS 140 SUMX=0: SUMY=0: SUMXY=0: SUMX2=0: DIFF=0 150 OPEN D$ AS #1 LEN=8 160 FIELD #1, 4 AS X$, 4 AS Y$ 170 FIN=ST+N-1 180 FOR I=ST TO FIN 190 GET #1,1 200 X=CVS(X$) 210  SUMX=SUMX+X 2  220 SUMX2=SUMX2+X 230 Y=CVS(Y$) 240 SUMY=SUMY+Y  250 SUMXY=SUMXY+X*Y  Program  -139-  L i n e a r R e g r e s s i o n Program - Continued 260 NEXT 2  270 K=N*SUMX2-SUMX 280  M=(N*SUMXY-SUMX*SUMY)/K  290 B=(SUMY*SUMX2-SUMX*SUMXY)/K 300 FOR I=ST TO FIN 310 GET #1, I 320  X=CVS(X$)  330 YCALC=X*M+B 340 Y=CVS(Y$) 350 DIFF=DIFF+(YCALC-Y)  2  360 NEXT 370 CLOSE #1 380 SDEV=SQR(DIFF/(N-1)) 390 TAG=TAG+1 400 LPRINT: LPRINT"CASE";TAG 410 LPRINT  "POINTS";ST;"THROUGH";FIN;"FIT  420 LPRINT  "SLOPE:" TAB(18)M;"VOLTS/SEC"  430 LPRINT  "INTERCEPT:" TAB(18)B;"VOLTS"  440 LPRINT  "STD.DEV.:" TAB(18) SDEV;"VOLTS"  450 CLS 460 PRINT "Do you want to f i t another 470  s e t of data from t h i s  ANS$=INPUT$(1)  480 IF ANS$="y" OR ANS$="Y" THEN CLS: GOTO 100 490 CLS 500 PRINT "Do you want to f i t data from another  file?"  file?"  -140-  L i n e a r R e g r e s s i o n Program - Continued 510  ANS$=INPUT$(1)  520  IF ANS$="y" OR ANS$="Y" THEN CLS: GOTO  530  LPRINT CHR$(27)CHR$(12)  540  STOP  550  END  -141-  Appendix B  Sieve A n a l y s e s and  C a l c u l a t i o n of the average  particle  diameters,  -142-  Table B . l - Sieve A n a l y s i s  Sieve Interval  P a r t i c l e Diameter ^jm  Weight Alumina  Percent Ottawa Sand  710-600  655  600-500  550  500-425  462.5  425-355  390  355-300  327.5  300-250  275  250-212  231  212-180  196  -  180-150  165  1.1  31.5  150-125  137.5  2.8  22.4  125-106  115.5  5.8  8.9  98  11.8  4.6  90-75  82.5  24.4  2.9  75-63  69  37.0  1.5  63-53  58  3.6  0.3  53-45  49  4.4  0.1  45-38  41.5  3.3  0.1  38-0  19  5.7  0.1  106-90  0.1 0.2 0.3 0.7 1.4 0.9 12.7 11.5  -143-  C a l c u l a t i o n o f mean p a r t i c l e  diameter:  i n 1^1  <t> /  d p  ±  i  3p  Sauter mean p a r t i c l e  dp^  Average  <t>^  Weight f r a c t i o n of p a r t i c l e s  Mean P a r t i c l e 1.  diameter  p a r t i c l e diameter of the i t h s i e v e  fraction  i n the i t h s i e v e  fraction  Diameters:  Alumina  3  •1 P b  _ b  ((0.91)/(165+10" ))+ 64xl0-  6  +((0.057)/(19xl0 ))  m  64 urn  2.  Sand 1  dp - 6  ((0.001)/(655xl0 ))+ 148xl0 148  um  - 6  m  +((0.001)/(19xl(r  ))  -144-  Appendix C Minimum F l u i d i z a t i o n , C a l c u l a t e d and E x p e r i m e n t a l , and C a l c u l a t i o n of Archimedes Numbers and T e r m i n a l V e l o c i t i e s  Calculated U f : m  1.  Alumina Pp = 3500 kg/m  3  6  3p = 65 x 1 0 ~ m g  = 9.81 m/s  2  Gas p r o p e r t i e s a t 25°C, 1 atm P u  = 1.1769 kg/m  g  3  b  = 1.8464 x 1 0 " kg/ms  g  3  Ar = P g ( P - P ) g p  3p /u  g  2 g  = 31 3  Since Ar < 1 0 , 2  U  = 0.00075 ( P - p ) g d p / u  m f  p  g  g  = 0.0057 m/s  2.  Ottawa  Sand  Pp = 2650 kg/m  ap = g  - 6  148 x 1 0  = 9.81 m/s  3  m  2  Gas p r o p e r t i e s at 25°C, 1 atm P u  g  = 1.1769 kg/m  3  5  g  = 1.8464 x 1 0 " kg/ms  Ar = 290 Since Ar < 1 0 U f * m  °'  0 2 3  3  -146-  30.0  i  i  |  i  |  i  |  GAS VELOCITY (m/s)  Figure C l  Minimum f l u i d i z a t i o n  v e l o c i t y determination  f o r alumina  -147-  Figure  C.2  Minimum f l u i d i z a t i o n  v e l o c i t y determination  f o r sand.  -148-  Terminal V e l o c i t y  Calculation:  I««[H I»] - log  pis  4  1/3 1 l"\ The v a l u e o f log[Nu ' ] c o r r e s p o n d i n g to log[Nd ' ] i s found i n Appendix A, p. 356-357 of Bubbles, Drops and P a r t i c l e s , C l i f t and Grace (1979) . l/3  H u  =  1 0  log[N  =  ]  1/3  N  IT  1 / 3 u  " 3 P  [ S ]l/3 ^(Pp-Pg)g^g  Gas  p  g  u  1.  properties  = 1.1769 kg/m  3  5  = 1.8464 x 1 0 " kg/ms  Alumina N  2.  at 25°C, 1 atm  1 / 3 d  = 3.4598  log[N  d  log[N  u  1 / 3  N  u  U  fc  1 / 3  ]  = 0.5391  1 / 3  ]  = -0.3740  = 0.4227  = 0.36 m/s  Sand N  1 / 3 d  = 7.2920  log[N  d  log[N  u  N U  1 / 3 u  t  1 / 3  ]  = 0.8628  1 / 3  ]  = 0.1054  = 1.2747  = 0.99 m/s  -149-  Appendix D Dashpot O i l S p e c i f i c a t i o n s  -150-  M o b i l 600 W C y l i n d e r O i l E n c l o s e d Gear L u b r i c a n t V i s c o s i t y SUS at 210°F (99°C) - 137/143 sec  -151-  Appendix E Data C o n v e r s i o n Formulae  -152-  1.  C i r c u l a t i o n Rate  G  G m  s  =  m  circ  m  A  ' cal  ' ?H 0 * b b 2  / A  fb  2  C i r c u l a t i o n r a t e (kg/m s)  s  circ  m ^ ca  Slope of the p r e s s u r e drop across time data ( v o l t s / s e c )  the b u t t e r f l y v a l v e  versus  Slope of the p r e s s u r e t r a n s d u c e r c a l i b r a t i o n c u r v e (m of H 0 / v o l t ) 2  A  A  3  PJJ^Q  D e n s i t y of water  bb  Cross-sectional  area of the b u b b l i n g bed (m )  fb  Cross-sectional  area of the f a s t bed (m )  2.  (kg/m ) 2  2  E f f e c t i v e Force  F  eff =  ^"V  m  ' L  * 8  '  X  V eff  F f£  Time averaged e f f e c t i v e f o r c e (N)  L  Time averaged load beam v o l t a g e  e  L  Q  m  L  Load beam v o l t a g e  (volts)  at no-flow c o n d i t i o n s  Slope of the weight v e r s u s v o l t a g e curve ( k g / v o l t s ) D i s t a n c e from the load beam c o n t a c t  (volts)  load beam c a l i b r a t i o n  point  to the p i v o t  ^eff  D i s t a n c e from the l e v e r p i v o t to the p o i n t where t h e e f f e c t i v e f o r c e Is s a i d to a c t , taken as 0.23 m  g  Acceleration  2  due to g r a v i t y (m/s )  (m)  -153-  Standard  a  jf  X  X  Deviation  m  e f f " °L * L  ' 8  X  * L  / X  eff  Standard d e v i a t i o n of the time averaged  e f f e c t i v e force  Standard d e v i a t i o n of the time averaged (volts)  load beam  ' L eff»  8  Defined  as  before  (N)  voltage  -154-  Appendix F Impact Flowmeter Raw  Data  Table F l - Time averaged load beam s i g n a l s and s i g n a l standard d e v i a t i o n s , converted to e q u i v a l e n t f o r c e s , f o r the 30° pan with alumina as the p a r t i c u l a t e m a t e r i a l ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l area)  Run //  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y , m/s  Test  #  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation, N  3.0  1 2 3 4  11.7 11.1 9.4 9.6  1.64 1.78 1.63  0.65 0.66 0.66  3.0  1 2 3 4 5  15.0 14.8 14.6 8.9 9.4  1.41 1.39 1.31 1.51 1.32  0.92 0.87 0.79 0.83 1.14  3.7  1 2 3 4 5  19.6 16.8 18.90 12.89 19.40  1.73 1.63 1.70 1.63 1.61  1.35 1.32 1.36 1.33 1.32  4.1  1 2 3 4 5  19.90  1.37 1.21 1.37 1.27 1.32  1.12 1.09 1.47 0.92 1.08  .. .continued  Ln  I  Run #  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y m/s  Test #  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation  5  4.1  1 2 3 4 5 6  46.2 40.3 51.9 48.4 41.1 69.2  3.89 3.86 3.72 3.81 3.88  1.67 1.71 1.73 1.71 1.71  6  4.8  1 2 3 4 5  48.4 44.6 51.42 54.24 58.06  5.02 5.00 4.84 4.75  0.92 0.97 1.01 1.23  7  5.3  1 2 3 4 5  61.85  5.04 4.91  0.91 1.04  8  4.2  1 2  12.33  1.43 1.48  0.56 0.55  9  3.3  1 2 3  11.65  1.72 1.28 1.22  1.55 1.12 0.42  T a b l e F2 - Time averaged load beam s i g n a l s and s i g n a l standard d e v i a t i o n s , c o n v e r t e d to e q u i v a l e n t f o r c e s , f o r the 45° pan with alumina as the p a r t i c u l a t e m a t e r i a l ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l area)  Run #  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y m/s  Test  #  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation, N  3.0  1 2 3 4  18.2 17.6 17.2  1.74 2.06 1.91 2.12  1.38 1.36 1.35 1.36  3.3  1 2 3  34.8  4.44 4.43 4.53  0.96 0.90 0.90  3.8  1 2 3 4  31.5 31.3  4.13 4.27 4.17 4.16  1.30 1.22 1.34 1.31  3.8  1 2 3 4  22.7  3.48 3.90 4.16 3.51  1.68 1.44 1.32 1.65  3.5  1 2 3  22.0 25.5  3.92 3.84 3.91  1.43 1.49 1.41  Ul  i  ...  continued  o,.n "  E  U  9 '  F a s t Bed s u p e r f i c i a l Gas Velocity 3.2  Test If  C i r c u l a t i o n Rate W - * 2  S i g n a l Standard Aviation, >  m/s 1 2  2 0  2  ' 19-7  3 3.2  Time Averaged Signal, »  1 2 3  n  2  ' 13.4  4.06 3.14 3.80  1.16 1.03 1.26  1.97 1.66 2.03  1.09 1.27 1.17  I t—>  tn  oo I  T a b l e F3 - Time averaged load beam s i g n a l s and s i g n a l standard d e v i a t i o n s , converted to e q u i v a l e n t f o r c e s , f o r the 60° pan with alumina as the p a r t i c u l a t e m a t e r i a l ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l a r e a s )  Run #  1  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y , m/s 4.3  Test  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation, N  1 2 3 4  21.7 29.3 23.8 17.7  1.22 0.84 1.17  1.42 1.02 1.20  4.4  1 2 3  24.0 27.8  0.90 1.09 1.14  1.45 1.52 1.62  4.4  1 2 3  49.3 64.5 53.7  1.96 2.63  1.87 1.87  3.4  1 2 3 4 5  64.54  2.70 2.65 2.49 1.19 2.14  1.81 1.72 1.75 0.94 1.60  3.6  1 2 3 4  17.1 17.1 16.8  1.12 1.09 0.73 1.20  0.98 0.99 0.80 1.03  ...  continued  I  F a s t Bed Gas V e l o c i t y , m/s  Test  #  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation, N  3.7  1 2 3 4  38.5 37.8  0.56 0.52 0.25 0.57  1.13 1.12 0.89 1.19  3.0  1 2 3 4  26.3 28.6 37.4 32.1  0.92 1.13 0.99 0.95  1.47 1.67 1.43 1.42  2.8  1 2 3 4 5  35.4 37.4 39.7 40.0 38.9  0.50 0.57 0.59 0.56 0.43  1.38 1.41 1.44 1.38 1.29  3.3  1 2 3 4  40.2 40.6  0.84 0.72 0.77 0.73  1.52 1.51 1.43 1.50  3.7  1 2 3 4 5  48.1 44.3 49.7 50.9 45.7  0.77 1.45 1.10 1.33 1.26  1.52 1.70 1.53 1.71 1.03  Table F4 - Time averaged load beam s i g n a l s and s i g n a l standard d e v i a t i o n s , c o n v e r t e d to e q u i v a l e n t f o r c e s , f o r 30° angle with sand as the p a r t i c u l a t e m a t e r i a l ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l area)  Run #  1  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y , m/s 4.5  5.1  Test  Circulation kg/m s 2  Rate  Time Averaged Signal, N  S i g n a l Standard Deviation, N  1 2 3  9.1 12.9 10.4  0.75 1.00 0.53  0.94 1.11 1.05  1 2 3  13.7 15.6  2.29 2.59 3.87  1.37 1.38 0.95 1.07 1.13 1.07  i  5.0  1 2 3 4  17.6 21.3 13.3 18.1  4.57 4.43 4.48  4.0  1 2 3  35.1 36.4 37.4  4.98 5.01 5.03  0.33 0.27 0.26  3.8  1 2 3  7.1 4.8 4.1  3.19 3.35 3.00  1.50 1.45 1.52  3.5  1 2 3  2.6  0.16 0.19 0.22  0.17 0.15 0.16  >—' I—•  I  T a b l e F5 - Time averaged load beam s i g n a l s and s i g n a l standard d e v i a t i o n s , c o n v e r t e d to e q u i v a l e n t f o r c e s , f o r 45° pan w i t h sand as the p a r t i c u l a t e m a t e r i a l ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l area)  Run #  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y , m/s  Test //  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation, N  3.0  1 2 3  6.3  0.32 0.33 0.32  0.04 0.05 0.03  3.0  1 2 3  7.2  0.10  0.07  4.0  1 2 3  14, 17, 13,  2.89 2.66 2.89  .56 ,65 .59  4.0  1 2 3 4  25.8 23.2 22.0 24.8  3.92 3.91 3.72  .47 .48 1.56  6.5  1 2 3  11.0 10.7 10.3  0.08 0.06 0.17  0.15 0.12 0.15  6.6  1 2 3  29.3 23.4  4.50 4.68 4.65  1.05 0.82 0.84  6.0  1 2 3  24.2 25.4 25.9  2.82 2.72 2.47  1.87 1.91 1.89  I  T a b l e F6 - Time averaged load beam s i g n a l s and s i g n a l standard d e v i a t i o n s , c o n v e r t e d to e q u i v a l e n t f o r c e s , f o r 60° pan with sand as the p a r t i c u l a t e m a t e r i a l ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l area)  Run #  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y , m/s  Test  //  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation, N  5.3  1 2 3  1.3 1.0 1.0  0.05 0.05 0.05  0.01 0.01 0.01  5.2  1 2 3  6.3 8.3 7.5  0.10 0.07 0.18  0.08 0.04 0.06  5.2  1 2 3  2.0 5.0 2.0  0.13 0.20 0.08  0.06 0.06 0.03  5.0  1 2 3  8.7 11.0 9.3  0.44 0.51  0.36 0.51  5.5  1 2 3  12.0 11.9 16.0  1.88 1.96 2.18  1.41 1.46 1.60  ...  continued  Run #  F a s t Bed S u p e r f i c i a l Gas V e l o c i t y , m/s  Test #  C i r c u l a t i o n Rate kg/m s 2  Time Averaged Signal, N  S i g n a l Standard Deviation, N  4.8  1 2 3  21.7 21.4 27.2  4.53 4.81 4.73  1.39 1.26 1.19  4.8  1 2 3  39.4 37.8 37.3  5.21 5.13 5.07  0.70 0.84 0.93  9.9 13.7 9.9  1.21 1.12 0.93  0.95 0.82 0.74  5.1  0.54 0.58 0.56  0.20 0.22 0.26  4.6  4.7  1 2 3  I  -165-  Appendix G P a r t i c l e V e l o c i t y Raw  Data  Table Gl - P a r t i c l e V e l o c i t i e s i n the L - v a l v e as a f u n c t i o n of C i r c u m f e r e n t i a l P o s i t i o n f o r d i f f e r e n t alumina c i r c u l a t i o n r a t e s ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l area)  Run  #  C i r c u l a t i o n Rate kg/m s  2  Test #  2  Position  #1  P a r t i c l e V e l o c i t y , m/s x 1 0 P o s i t i o n #2 P o s i t i o n #3 Position  #4  Position  1  21.2  1 2 3  2.14 2.04 1.94  2.07 2.00 2.01  2.08 1.99 2.00  2.07 1.97 2.01  1.94 1.98 1.89  2  60.2  1 2 3  5.60 5.43 5.58  5.96 5.38 5.22  4.96 4.91 6.73  5.49 5.14 5.95  5.29 6.13 5.28  3  13.4  1 2 3  1.09 1.03 1.00  1.06 1.00 1.17  0.93 1.17 1.12  1.03 1.06 1.17  1.04 0.90 1.15  4  38.8  1 2 3 4  4.58 3.61 4.20 4.83  3.97 4.42 5.24 3.52  4.32 5.53 3.47 3.75  4.30 5.76 3.51 3.77  4.35 3.18 4.03 3.39  5  38.0  1 2 3 4  5.06 5.01 5.41 5.45  3.33 3.06 3.02 3.07  3.10 3.94 3.31 3.35  3.37 3.10 5.08 4.99  3.31 3.08 4.33 2.94  #5  .. c o n t i n u e d  Run  #  C i r c u l a t i o n Rate kg/m s  Test #  2  2  Position  #1  P a r t i c l e V e l o c i t y , m/s x 1 0 P o s i t i o n #2 P o s i t i o n #3 Position  #4  Position  6  35.1  1 2 3  3.50 3.18 3.41  3.22 3.47 3.44  3.41 3.39 3.66  3.52 3.78 3.60  3.30 3.49 3.42  7  52.5  1 2 3 4 5  4.37 4.99 4.46 4.04 5.28  4.04 6.00 4.46 5.70 4.14  5.57 5.22 5.38 4.70 4.74  5.56 5.23 4.33 4.51 4.88  5.12 4.68 4.83 4.65 4.55  8  17.1  1 2 3 4  1.47 1.45 1.74 1.71  —  1.83 1.48 1.44 1.31  _  _  -  -  2.33 2.11 2.32  —  2.09 2.22 1.82  —  —  -  -  -  4.46 4.69 4.27 4.77 4.64  _  4.58 4.39 4.78 4.87 4.58  _  —  —  -  4.23 4.12 5.85 3.80 3.08  _  4.76 3.27 3.64 4.76 3.15  _  _  -  -  9  10  11  21.7  35.4  40.2  1 2 3 1 2 3 4 5 1 2 3 4 5  -  -  -  -  -  -  -  -  -  #5  -  -  .. .continued  Run  #  C i r c u l a t i o n Rate kg/m s  Test #  2  P o s i t i o n #1  P a r t i c l e V e l o c i t y , m/s P o s i t i o n #2 P o s i t i o n #3  12  47.9  1 2 3 4  4.95 4.53 4.89 5.07  -  4.66 5.34 4.92 5.05  13  49.3  1 2 3 4 5  6.54 7.10 7.22 6.84 7.12  -  6.95 6.26 6.83 6.50 6.89  14  11.7  1 2 3  0.80 0.86 0.97  -  0.89 0.83 0.86  15  15.0  1 2 3 4  1.37 1.31 1.56 1.28  -  1.69 1.41 1.36 1.40  16  19.6  1 2 3 4  1.80 1.97 1.98 1.88  -  1.76 1.81 2.10 2.01  17  19.9  1 2 3 4  2.48 2.18 2.56 2.41  -  2.10 2.11 2.56 2.47  x  2  10 P o s i t i o n #4  Position  continued  #5  Run  #  C i r c u l a t i o n Rate kg/m s  Test P o s i t i o n #1  2  P a r t i c l e V e l o c i t y , m/s P o s i t i o n #2 P o s i t i o n #3  18  46.2  1 2 3 4  4.05 4.84 4.37 4.63  4.91 4.40 4.50 4.72  19  48.5  1 2 3 4 5  6.15 0.35 6.01 5.57 6.48  6.43 6.19 6.78 7.84 6.81  x  2  10 Position  #4  Position  //5  Table G2 - P a r t i c l e V e l o c i t i e s i n the L - v a l v e as a f u n c t i o n of C i r c u m f e r e n t i a l P o s i t i o n f o r d i f f e r e n t sand c i r c u l a t i o n r a t e s ( c i r c u l a t i o n r a t e s based on the f a s t bed c r o s s - s e c t i o n a l area)  Run  f?  C i r c u l a t i o n Rate kg/m s  2  Test #  2  P o s i t i o n #1  P a r t i c l e V e l o c i t y , m/s x 1 0 P o s i t i o n //2 P o s i t i o n #3 Position  #4  Position  1  14.2  1 2 3  1.11 1.15 1.25  1.14 1.18 1.14  1.13 1.21 1.11  1.13 1.22 1.10  1.25 1.24 1.18  2  25.8  1 2 3  1.66 1.74 1.63  1.76 1.68 1.64  1.70 1.65 1.70  1.68 1.80 1.74  1.83 1.77 1.83  3  11.0  1 2 3  0.92 0.91 0.91  0.90 0.95 0.92  1.01 0.95 0.93  0.92 0.92 0.90  1.04 0.87 1.00  4  29.3  1 2 . 3  2.46 2.55 2.31  2.42 2.68 2.62  2.43 2.55 2.48  2.43 2.24 2.43  2.48 2.75 2.34  5  24.4  1 2 3  1.70 1.59 1.68  1.86 1.74 1.73  1.72 1.83 1.73  1.93 1.68 1.92  1.98 1.66 1.85  6  6.3  1 2 3  0.39 0.39 0.39  0.40 0.37 0.38  0.39 0.39 0.40  0.39 0.39 0.38  0.38 0.38 0.37  continued  #5  —i  o  Run  #  C i r c u l a t i o n Rate kg/m s  10  2  Test #  2  P o s i t i o n #1  P a r t i c l e V e l o c i t y , m/s x 1 0 P o s i t i o n #2 P o s i t i o n //3 P o s i t i o n #4  Position  7.3  1 2 3  0.70 0.71 0.68  0.71 0.67 0.66  0.71 0.69 0.70  0.66 0.68 0.70  0.70 0.70 0.73  13.7  1 2 3  1.08 1.10 1.15  1.11 1.07 1.02  1.12 1.18 1.18  1.14 1.10 1.17  1.28 1.29 1.25  17.6  1 2 3  1.64 1.72 1.75  .68 .80 .62  1.75 1.72 1.69  1.76 1.68 1.81  1.86 1.70 1.87  35.3  1 2 3  2.48 2.54 2.39  35 42 40  2.62 2.20 2.62  2.16 2.33 2.42  2.58 2.50 2.32  11  6.3  1 2 3  0.82 0.83 0.82  0.81 0.76 0.84  0.81 0.79 0.79  0.87 0.81 0.81  0.82 0.87 0.81  12  1.8  1 2 3  0.64 0.65 0.70  0.67 0.67 0.67  0.68 0.71 0.67  0.62 0.67 0.68  0.65 0.68 0.68  13  2.4  1 2 3  0.49 0.49 0.50  0.51 0.47 0.48  0.50 0.49 0.50  0.47 0.50 0.50  0.48 0.48 0.51  #5  continued  i i—• i  Run  #  C i r c u l a t i o n Rate kg/m s  Test #  2  P o s i t i o n #1  P a r t i c l e V e l o c i t y , m/s P o s i t i o n #2 P o s i t i o n #3  x  2  10 Position  #4  Position  14  8.7  1 2 3  0.88 0.88 0.90  0.86 0.86 0.94  0.95 0.89 0.89  0.93 0.91 0.93  0.94 0.96 0.88  15  12.0  1 2 3  1.30 1.27 1.15  1.20 1.23 1.22  1.34 1.32 1.25  1.29 1.16 1.27  1.29 1.32 1.26  16  21.7  1 2 3  2.08 2.12 2.12  2.00 2.04 2.17  2.16 2.02 2.06  2.01 2.06 1.97  1.97 1.92 2.06  17  39.5  1 2 3  2.54 2.39 2.56  2.75 2.67 2.53  2.40 2.39 2.55  2.68 2.82 2.51  2.42 2.40 2.67  18  9.9  1 2 3  1.01 0.94 1.06  0.99 1.03 1.02  0.96 1.03 0.96  1.01 0.92 0.96  0.94 0.94 1.01  19  5.1  1 2 3  0.80 0.80 0.74  0.77 0.78 0.80  0.80 0.80 0.81  0.84 0.74 0.82  0.79 0.82 0.78  #5  -173-  Appendix H T h e o r e t i c a l Model  -174-  Force on Pan i n C r o s s f l o w Linear  Momentum Theorem:  within  the c o n t r o l volume = time r a t e of change of momentum w i t h the  c o n t r o l volume p l u s volume, F i g u r e  Net F o r c e a c t i n g on p a r t i c l e s and f l u i d  net r a t e of o u t f l o w of momentum from the c o n t r o l  H.l.  Since we a r e i n t e r e s t e d  case, the time r a t e of change term i s z e r o . contribution  only  i n the steady  state  L e t us i g n o r e the  o f the gas to the momentum and f o r c e  since  Pg «  pp.  The pan and c o n t r o l volume adopted a r e shown i n F i g u r e H . l . Then:  F =  where:  F G  f o r c e (N)  s  = total  s o l i d s mass flow i n the slow bed (kg/s)  Z, = bar l e n g t h b  (m)  w^j. = width of zone where p a r t i c l e s a r e i n t e r c e p t  by the bar (m) 2  = c r o s s - s e c t i o n a l area of the slow bed column (m ) v  g  = entry  v e l o c i t y o f p a r t i c l e s , assumed =  terminal  s e t t l i n g v e l o c i t y minus gas v e l o c i t y i n the slow bed (m/s) v^ = average f i n a l v e l o c i t y as p a r t i c l e s l e a v e the c o n t r o l s u r f a c e (m/s) 9^ = angle between p a r t i c l e t r a j e c t o r y l e a v i n g c o n t r o l volume and For  the s i m p l e s t  the v e r t i c a l downward d i r e c t i o n  case, assume w^ = w^ = pan width,  v  s e t t l i n g v e l o c i t y and, 9^ = 9^ = angle of pan slope Then: G F =  L w, v s b b e  f  =  v  = e  v  = t  terminal  to v e r t i c a l  -175-  V  nuiuunii  Vj  Figure H.l  e  Control Volume  Schematic of the bar c r o s s - s e c t i o n and c o n t r o l volume  -176-  Example: G  Sand, 45° pan 2  S  = 50 kg/m -s x 1 x ( 0 . 1 5 ) Q  2  m  2  = 0.884 ^ £ s  K - 14" = 0.356 m b w. = 2" » 0.0508 m b v  = 0.99 m/s  A 6  2  = J  U  = 45°  2  x (14x0.0254) m  2  = 0.0993  m  2  D  0.884  x 0.356 m x 0.0508 m  .-. F -  x 0.99 - x (1-0.707) 0.0993 m  - 0.047 N  2  8  -177-  In F i g u r e H.2 the e x p e r i m e n t a l r e s u l t s alumina  as the c i r c u l a t i n g s o l i d s  p r e d i c t e d by the t h e o r e t i c a l evident  that  prediction  the p r e d i c t i o n  are compared w i t h the r e s u l t s  model, shown by the s o l i d by the t h e o r e t i c a l  by the t h e o r e t i c a l  - non-uniform  f o r the 60° pan angle with  model i s poor.  model may have r e s u l t e d  distribution  of s o l i d s  line.  It i s The poor  from:  i n the "slow"  bed column.  - particles  sticking  to and/or s i t t i n g  - particles  bouncing  or coming o f f the pan a t angles o t h e r than t h  assumed -  on the pan.  angle  the p a r t i c l e s  not t r a v e l l i n g at t h e i r  t e r m i n a l v e l o c i t i e s when  they s t r u c k the pan. The  f a i l u r e to i n c l u d e the f i r s t  cause u n d e r e s t i m a t i o n of the a c t u a l p o i n t would cause Clearly, also  fails  results.  three p o i n t s i n the model would  results.  E x c l u s i o n of the f o u r t h  the model to o v e r e s t i m a t e the e x p e r i m e n t a l  the model underestimates  to p r e d i c t  results.  the e x p e r i m e n t a l r e s u l t s .  the three zones apparent  It  i n the e x p e r i m e n t a l  T h i s i s because the model does not account  for sticking  of t h  equipment at lower c i r c u l a t i o n r a t e s or peaking of the equipment at higher s o l i d s  fluxes.  As a r e s u l t cannot  be used  of the s i m p l i f y i n g  to e s t i m a t e expected  assumptions forces.  made i n t h i s model, i t  -178-  Figure  H.2  Comparison of the e x p e r i m e n t a l r e s u l t s f o r the 60° pan with alumina w i t h the r e s u l t s p r e d i c t e d by the t h e o r e t i c a l model.  -179-  Appendix Operating  I  Instructions  -180-  1.1  Electrical  Connections  B e f o r e working on any of the e l e c t r i c a l equipment should  I.1.1 1.  connections,  of a l l the  be turned o f f .  Load Beam Connection  The f i v e w i r e s  and Adjustment  of the l o a d beam a r e c o l o u r coded.  The w i r e s a r e  connected to the a m p l i f i e r u s i n g the t e r m i n a l b l o c k a t the back of the amplifier.  Each l o a d beam wire  i s connected to i t s a p p r o p r i a t e  t e r m i n a l , as i n d i c a t e d by the a b b r e v i a t i o n of the wire c o l o u r  beside  the t e r m i n a l , u s i n g the screws i n the t e r m i n a l b l o c k , F i g u r e 1.1. 2.  The output  v o l t a g e of the a m p l i f i e r i s measured a c r o s s  the t e r m i n a l s  marked +0 v o l t s and -0 v o l t s , F i g u r e 1.1. 3.  The output adjusted  v o l t a g e of the l o a d beam under no-load  to zero by the coarse  and f i n e  c o n d i t i o n s can be  zero adjustment screws on the  f r o n t panel of the a m p l i f i e r , F i g u r e 1.2.  1.1.2 1.  Load Beam A m p l i f i e r  Connections  When u s i n g two or more s i g n a l r e c o r d e r s , such as the UV c h a r t c h a r t r e c o r d e r , the d i g i t a l v o l t m e t e r  and/or the Tecmar d a t a l o g g i n g  board,  ensure t h a t a l l of the ground leads of the equipment are connected to the -0 v o l t s  t e r m i n a l and a l l of the h i g h p o t e n t i a l leads a r e connected  to the +0 v o l t s . be  short  I f t h i s i s not f o l l o w e d , the l o a d beam a m p l i f i e r w i l l  circuited.  -181-  LOAD BEAM TERMINALS  OUTPUT VOLTAGE TERMINALS  POWER CORD GROUND TERMINAL  F i g u r e 1.1  Load beam a m p l i f i e r  TERMINAL BLOCKS  t e r m i n a l block c o n n e c t i o n s  -182-  POWER INDICATOR LIGHT FUSE COARSE ZERO ADJUSTMENT ON/OFF SWITCH  FINE ZERO ADJUSTMENT  F i g u r e 1.2  Load beam a m p l i f i e r  controls  -183-  1.1.3 1.  Tecmar  Connections  A l l datalogging  connections  c a b l e , F i g u r e 1.3. beam and p r e s s u r e respectively.  a r e made u s i n g the daughter board  As d e s i g n a t e d transducer  i n the d a t a l o g g i n g  are datalogged  program, the l o a d  u s i n g Channels 0 and 1  The r i b b o n leads c o r r e s p o n d i n g  shown i n F i g u r e 1.3.  ribbon  t o Channels 0 and 1 a r e  -184-  RED  STRIPE  m  +  1  +  1  o o — —  z z z z z z z z < << < X X X X u u u u  Figure  1.3  Tecmar daughter  board r i b b o n  cable  -185-  1.2  1.2.1 1.  Impact Flowmeter Column S e c t i o n Removal  Disconnect  the load beam from  terminal block 2.  Impact Flowmeter O p e r a t i o n  the load beam a m p l i f i e r by l o o s e n i n g the  screws.  Remove the a i r purge and manometer l i n e s  connected  to the p r e s s u r i z e d  box. 3.  Remove the screw which holds the grounding flowmeter  4.  to the support  Disconnect  w i r e s of the impact  column.  the manometer l i n e a t t a c h e d to the Impact flowmeter  column  section. 5.  Remove the b o l t s from the upper and lower flowmeter  6.  column  section.  Loosen the nuts which f a s t e n the mounting b r a c k e t s of the s e c t i o n s of r e t u r n column o v e r l y i n g the column support  7.  f l a n g e s of the impact  the impact  flowmeter  to the support b r a c k e t s o f  post.  Remove the b o l t s from the primary c y c l o n e which l i e below the support b r a c k e t of the primary c y c l o n e .  8.  R a i s e the primary c y c l o n e and a t t a c h e d r e t u r n column w i t h a l e v e r . P l a c e b l o c k s between the primary c y c l o n e mounting b r a c k e t s and the support b r a c k e t s to keep the c y c l o n e and a t t a c h e d column s e c t i o n s elevated.  9.  The impact  flowmeter  column s e c t i o n can now be s l i p p e d out of the  r e t u r n column. 10. To I n s t a l l procedures. properly.  the impact Ensure  flowmeter  column s e c t i o n , r e v e r s e the above  that the rubber gasket and 0 - r i n g s are p o s i t i o n e d  -186-  1.2.2 1.  Pressurized  Carry  out steps  Box Removal 1 through 3 of the impact flowmeter column s e c t i o n  removal. 2.  Remove the Swagelock b o l t which s e a l s the port beam c a b l e  enters  through which the load  the p r e s s u r i z e d box.  3.  Remove the b o l t s h o l d i n g  4.  Carefully pull  the box a g a i n s t  the mounting p l a t e .  the box away from the mounting p l a t e .  Avoid  p u l l i n g the  rubber gasket o f f the mounting p l a t e . 5.  Once the box i s f r e e , d i s c o n n e c t l e v e r arm to the p r e s s u r i z e d  the grounding wire l e a d i n g  box by l o o s e n i n g  from the  the b o l t on the l e v e r  arm. 6.  The box can now be removed.  As the box i s p u l l e d away, s l i p  of the load beam through i t s Swagelock 7.  fitting.  The box i s i n s t a l l e d by r e v e r s i n g the above p r o c e d u r e s . between the rubber gasket and box should to s e a l a g a i n s t  the c a b l e  The s u r f a c e  be covered w i t h vacuum g r e a s e  leakage when the box i s p r e s s u r i z e d .  -187-  1.2.3  Pan Removal and  Replacement  1.  C a r r y out  the procedures  o u t l i n e d i n S e c t i o n 1.2.2.  2.  Remove the l o a d beam from i t s mounting bracket by undoing the fastening  bolts.  3.  C a r r y out  the steps o u t l i n e d i n S e c t i o n 1.2.1.  4.  Detach the pan  5.  I f the pan  from the l e v e r arm  by removing the s i x mounting  the b l o c k s o f f the end  of the  The  b l o c k s are i n s t a l l e d by r e v e r s i n g procedure  7.  Fasten  the new  pan  secure  the pan  to the mounting b l o c k s .  8.  Centre  the pan  i n the column and  9.  T i g h t e n the screws h o l d i n g the mounting b l o c k s to the  to the mounting b l o c k s w i t h  5.  the s i x screws which  ensure t h a t the pan  is level. lever.  the l o a d beam.  11. For t h i s step the l o a d beam must be connected d u r a t i o n of the procedure  only.  Balance  to the a m p l i f i e r  counter-weight,  l o o s e n the nuts which secure  the w e i g h t .  Starting  nuts.  12. Reverse procedures  the l o a d beam a m p l i f i e r 1 through  3.  the  by t u r n i n g the  l o c k i n g nuts a q u a r t e r t u r n c l o c k w i s e .  Disconnect  until  with  the a m p l i f i e r v o l t a g e at  Reduce the v a l u e of the counter-weight  counter-weight  This  To move the  the l e v e r c o n t a c t i n g the l o a d beam, move the counter-weight load beam a m p l i f i e r v o l t a g e j u s t equals  f o r the  the l e v e r / p a n assembly.  i s done by a d j u s t i n g the l e v e r counter-weight.  no-load.  sliding  lever.  6.  10. R e i n s t a l l  screws.  i s being exchanged, remove the p r e v i o u s pan's mounting  b l o c k s by l o o s e n i n g the screws on the bases of the b l o c k s and  new  two  connections.  T i g h t e n the l o c k  -188-  1.2.4  Bearing  Adjustment  1.  C a r r y out the steps o u t l i n e d i n S e c t i o n 1.2.2.  2.  Loosen the a l i e n screws used to l o c k the b e a r i n g s h a f t s i n p l a c e . These are l o c a t e d on the f r o n t s of the b e a r i n g s h a f t b l o c k s . n e c e s s a r y to remove the load beam to access  3.  The b e a r i n g s h a f t s may  now  be a d j u s t e d .  I t may  be  them.  To remove the p i v o t , back the  b e a r i n g s h a f t s i n t o the b e a r i n g b l o c k s by t u r n i n g the s h a f t s counter-clockwise. 4.  The p i v o t can now  be removed.  To s e t the b e a r i n g , press the b e a r i n g s h a f t s i n t o the p i v o t as f a r as they w i l l go by t u r n i n g the k n u r l e d knobs Slowly back the s h a f t s out u n t i l  of the s h a f t s c l o c k w i s e .  the p i v o t moves f r e e l y .  the s e n s i n g screw of the l o a d beam c o n t a c t s the l e v e r . change  shaft  counter-clockwise.  Once the b e a r i n g Is a d j u s t e d and the l e v e r p o s i t i o n e d , t i g h t e n the b e a r i n g s h a f t l o c k i n g screws.  6.  I f i t does not,  the p o s i t i o n of the l e v e r by r o t a t i n g one b e a r i n g s h a f t  c l o c k w i s e and the other 5.  Ensure t h a t  Reverse step  1.  

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