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The thermal conductivities of cis and trans decahydronaphthalene Robinson, Donald B. 1946

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(Hi By  THE THERMAL CONDUCTIVITIES OP CIS AND TRANS DECAHYDRANAPHTHALENE  by Donald B . R o b i n s o n  A Thesis submitted i n P a r t i a l  Fulfilment  t h e Requirements f o r the Degree o f MASTER OF APPLIED SCIENCE i n t h e Department of CHEMICAL ENGINEERING  The U n i v e r s i t y o f B r i t i s h Columbia July,  1946.  of  ACKNOWLEDGEMENT  The a u t h o r w i s h e s t o acknowledge t h e a s s i s t a n c e o f Andrew H . Younger w i t h whom t h i s work was c a r r i e d o u t .  He w i s h e s t o acknowledge  the a d v i c e and s u g g e s t i o n s g i v e n by D r . W. E . S e y e r , under whose d i r e c t i o n t h i s r e s e a r c h was undertaken.  TABLE OF CONTENTS Page I. II.  III.  Introduction  1  The Thermal C o n d u c t i v i t y o f L i q u i d s  1  A . Theory  1  B . Measurement D i f f i c u l t i e s  2  1. G e n e r a l 2. I n L i q u i d s  2 2  C. The Method Used  5  D e s c r i p t i o n of Apparatus A . The T e s t C e l l 1.  Calorimeters  2. Walls  IV. V.  6 6 6  1  B . The H e a t e r s  7  C. Temperature Measurements  8  D. P o s i t i o n o f Thermocouples  9  E . Water S u p p l y  10  F. Heating C i r c u i t  10  Procedure  10  Results  11  A . Theory o f Measurement  11  Bi. The Thermal C o n d u c t i v i t y o f Water  12  C. The Thermal C o n d u c t i v i t y o f the Decahydranapthalenes 1. P r e p a r a t i o n o f M a t e r i a l s 2. Trans Deoahydranapthalene 3. G i s Decahydranapthalene 4. E x p l a n a t i o n o f R e s u l t s  15 15 15 17 19  TABLE OF CONTENTS ( C o n t ' d ) Page VI.  VII. VIII.  Suggestions f o r Future Operation of Apparatus  the  20  A . Connections  20  B. Thermopiles  21  G. C o n t a i n e r  21  Suggestions f o r Future Research  22  Conclusion  22  1  THE THERMAL CONDUCTIVITIES OF CIS AND TRANS DECAHYDRANAPTHALENE  INTRODUCTION A knowledge o f the t h e r m a l c o n d u c t i v i t i e s o f l i q u i d hydrocarbons i s o f importance i n d u s t r i a l l y and t h e o r e t i c a l l y . I n d u s t r i a l l y , the thermal c o n d u c t i v i t i e s are o f v a l u e i n the design o f heat t r a n s f e r lubricating oils.  equipment and i n the compounding o f  T h e o r e t i c a l l y , thermal c o n d u c t i v i t i e s are  needed t o determine t h e way hydrocarbons t r a n s f e r  heat i , e .  by r o t a t i o n o f atoms o r by s i m p l e v i b r a t i o n s . Thus our p r o b l e m has two p u r p o s e s ;  f i r s t , to  build  an a p p a r a t u s f o r m e a s u r i n g t h e t h e r m a l c o n d u c t i v i t i e s o f v a r i o u s l i q u i d h y d r o c a r b o n s and s e c o n d , t o c o n t i n u e t h e i n v e s t i g a t i o n s a l r e a d y made i n t h i s l a b o r a t o r y on t h e p h y s i c a l p r o p e r t i e s o f © i s and t r a n s  decahydranapthalene.  THE THERMAL CONDUCTIVITIES OF LIQUIDS Theory The t h e r m a l c o n d u c t i v i t y " K " o f a substance measure o f t h e heat t r a n s f e r conduction.  is a  t h r o u g h t h e substance due t o  I t i s b e s t d e f i n e d by the F o u r i e r e q u a t i o n .  C o n s i d e r a s m a l l a r e a dA i n t h e m a t e r i a l whose t h e r m a l c o n -  2. ductivity i s required.  I f < | f i i s t h e temperature  gradient  normal t o dA i n t h e d i r e c t i o n x , t h e n the q u a n t i t y o f h e a t dQ, f l o w i n g t h r o u g h dA i n u n i t t i m e d t i s g i v e n b y : dQ, = K dA  ox I n t h e s t e a d y s t a t e o f heat f l o w . t h e e q u a t i o n b e comes Q, » K A  /S, P C  F o r l i q u i d s i n p a r t i c u l a r , B r i d g e m a n has worked 1  out a t h e o r e t i c a l e q u a t i o n w h i c h checks f a i r l y w e l l w i t h e x perimental, data.  Smith  2  has used d i m e n s i o n a l a n a l y s i s t o o b -  t a i n v a r i o u s e m p i r i c a l r e l a t i o n s h i p s t h a t show good agreement w i t h experiment. as  However, t h e s e e q u a t i o n s  can be used o n l y  approximations.  Measurement  Difficulties  General:  The t h e r m a l c o n d u c t i v i t y o f any s u b s t a n c e i s  c o n s i d e r e d t o be one o f t h e more d i f f i c u l t t o measure w i t h any degree o f a c c u r a c y . asons f o r t h i s i s t h e n o n - e x i s t a n c e  p h y s i c a l constants  One o f t h e main r e -  o f an i n s u l a t o r i n t h e  e l e c t r i c a l sense t h a t w o u l d enable heat f l o w t o be d i r e c t e d i n any d e s i r e d c h a n n e l .  A l s o t h e r e i s not t h e  instantaneous  a t t a i n m e n t o f e q u i l i b r i u m t h a t t h e r e i s i n an e l e c t r i c a l system. In Liquids: f e r by o o n v e c t i o n .  The main p r o b l e m i s t o p r e v e n t heat t r a n s T h i s i s accomplished i n d i f f e r e n t  depending on the method  used.  1  P r o c . Am. A c a d . A r t and S c i . 59 N o . 7 141  2  I n d . and'Eng. Chem. 23, 416 (1931)  (#23)  ways,  3. Flow methods were used by C a l l e n d a r ? and N e t t l e t o n 4 . However, many d i f f i c u l t i e s a r e encountered i n t h e s e methods and u s u a l l y s e v e r a l a p p r o x i m a t i o n s t h a t c a n n o t a l w a y s be j u s t i f i e d are required.  Hence i n r e c e n t y e a r s no a t t e m p t s  have been made t o use f l o w methods. Most i n v e s t i g a t o r s have measured t h e t h e r m a l c o n d u c t i v i t y w i t h the l i q u i d i n the steady s t a t e u s i n g a t h i n film or a thick disc.  The t h e r m a l c o n d u c t i v i t y i s found from  t h e s t e a d y s t a t e e q u a t i o n ( g i v e n under t h e o r y ) , a l l t h e o t h e r q u a n t i t i e s i n t h i s equation being measurable. Two t y p i c a l examples o f t h i n f i l m methods a r e t h o s e o f Kaye and Higgins-5 and B r i d g e m a n ^ . Kaye and H i g g i n s  1  apparatus  c o n s i s t e d o f a n upper  h e a t i n g b l o c k and a l o w e r c o o l i n g b l o c k .  The t h i n f i l m o f  l i q u i d was p l a c e d between t h e s e two b l o o k s . the o u t s i d e p r e v e n t e d o v e r f l o w .  A g a l l e y around  A guard h e a t e r above t h e h o t  b l o c k stopped heat from e s c a p i n g upwards and thus a l l t h e heat was t r a n s m i t t e d t h r o u g h t h e l i q u i d .  The two b l o c k s were  s e p a r a t e d a known d i s t a n c e , by t h r e e g l a s s rods*  Corrections  were a p p l i e d by t e s t i n g t h e apparatus w i t h a m a t e r i a l o f known t h e r m a l c o n d u c t i v i t y . A n o t h e r t y p e o f f i l m a p p a r a t u s was d e v i s e d by Bridgeman and used by Smith? and o t h e r s .  T h i s method c o n -  s i s t e d o f u s i n g two c o n c e n t r i c c y l i n d e r s w i t h t h e l i q u i d b e -  ? P h i l . T r a n s . R o y . S o c . 119, 110 (1902) 4  P h . Mag. 19, 587 (1910)  S P r o c . R o y . S o c . (London) A117, 4-59 (1928) 6LOO. C i t . 7  I n d . and E n g . Chem. 22, 1246 (1930)  4. tween them.  The i n t e r i o r o f t h e c e n t r e c y l i n d e r was heated  by a r e s i s t a n c e w i r e , t h e heat f l o w i n g r a d i a l l y o u t w a r d s . The i n p u t o f heat was o b t a i n e d by measuring t h e e l e c t r i c a l energy t o t h e w i r e .  The temperature d i f f e r e n c e was measured  by thermocouples and t h e t h i c k n e s s o f t h e f i l m was d e t e r m i n e d by c a l i b r a t i n g w i t h a known l i q u i d .  Thus t h e a c c u r a c y d e -  pended on some p r e v i o u s measurement. The main drawbacks o f t h e t h i n f i l m methods a r e : (1) d i f f i c u l t y  i n measuring t h e t h i c k n e s s o f t h e f i l m  (2) s m a l l temperature  drop a c r o s s t h e f i l m  Bates apparatus 8  d i s c method.  i s t h e b e s t example o f t h e t h i c k  I n t h i s method t h e l i q u i d i s heated from t h e  t o p and c o o l e d from t h e bottom and thus c o n v e c t i o n c u r r e n t s are prevented.  B a t e s ' apparatus c o n s i s t e d o f a c i r c u l a r  c o n t a i n e r t h e w a l l s o f w h i c h were made o f b a k e l i t e .  The t o p  was a c e n t r e h e a t e r and a g u a r d h e a t e r i n s u l a t e d from each other.  The bottom was s p i r a l f l o w w a t e r c a l o r i m e t e r s u r -  rounded by a guard r i n g c a l o r i m e t e r . s u l a t e d from eaoh o t h e r .  These were a l s o i n -  Thus t h e l i q u i d i n t h e c o n t a i n e r  was between two s u r f a c e s a known d i s t a n c e a p a r t .  The guard  r i n g s were so a d j u s t e d t h a t a u n i f o r m temperature  existed  through h o r i z o n t a l planes i n the l i q u i d .  The heat f l o w was  measured by t h e s p i r a l f l o w w a t e r c a l o r i m e t e r , t h e a r e a o f w h i c h had been d e t e r m i n e d p r e v i o u s l y .  The t e m p e r a t u r e  gra-  d i e n t t h r o u g h t h e l i q u i d was measured by thermocouples stretched h o r i z o n t a l l y through the l i q u i d . 8  9  I n d . and E n g . Chem. 25, 431 (1933) I n d . and E n g . Chem. 28, 494 (1936)  Thus a l l t h e  terms i n t h e F o u r i e r e q u a t i o n a r e known and t h e r e q u i r e d t h e r m a l c o n d u c t i v i t y can he c a l c u l a t e d . The advantages o f t h i s method  are:  (1) I t does not. depend on the t h e r m o o o n d u c t i v i t y o f some o t h e r l i q u i d used t o c a l i b r a t e t h e a p p a r a t u s . (2) The temperature g r a d i e n t t h r o u g h the f i l m can be o b <X.fC  t a i n e d and thus s u r f a c e  effects'"eliminated.  (3) I t does not r e q u i r e so a c c u r a t e measurement  of  the  t e m p e r a t u r e d i f f e r e n c e as the f i l m method.  The Method Used Our method was an a d a p t i o n o f B a t e s ' .  There were  two problems i n p a r t i c u l a r t o be c o n s i d e r e d .  First,  the  amount o f h y d r o c a r b o n a v a i l a b l e was l i m i t e d .  Thus i t was  n e c e s s a r y t o reduce the volume o f the c o n t a i n e r from 2000 c o s . as i n B a t e s ' a p p a r a t u s t o 250 c c s . i n our a p p a r a t u s . a new m a t e r i a l f o r t h e c o n t a i n e r had to be f o u n d as attacks  bakilite.  Second, "deealin  I t was f i n a l l y d e c i d e d t o use a  , | X  "transite"  +  c o n t a i n e r s i n c e i t had a l o w t h e r m a l c o n d u c t i v i t y and was r e sistant  to d e c a l i n .  A p r o b l e m t h a t a r o s e was how t o  the bottom c a l o r i m e t e r t o the t r a n s i t s  container.  attach  After  ex-  p e r i m e n t i n g w i t h numerous g l u e s and cements i t was d e c i d e d t o j o i n the two p a r t s t o g e t h e r w i t h "Lepages"^ g l u e and c o v e r t h e ujaod.  o u t s i d e w i t h l i t h a r g e cement and the i n s i d e w i t h p l a s t i c * g l u e . These m a t e r i a l s were - r e s i s t a n t t o d e c a l i n . Commercial name f o r a m i x t u r e o f c i s and t r a n s napthalene. * Trade name o f Johns M a n v i l l e L t d . * Trade name o f Le P a g e ' s I n c . s  decahydra-  6. DESCRIPTION Off APPARATUS The equipment c o n s i s t e d o f t h r e e main p a r t s ;  a  source o f w a t e r a t c o n s t a n t  t e m p e r a t u r e and p r e s s u r e ,  test c e l l i n i t s container,  and a s w i t o h b o a r d as shown i n  figure  the  1.  The Tes-b C e l l The t e s t c e l l i s shown d i a g r a m a t i c a l l y i n f i g u r e  2.  I t consisted of a shallow c y l i n d r i c a l container approximately 2 cm. h i g h and 11.5  cm. i n d i a m e t e r .  The w a l l was  transits  p i p i n g , the bottom was a smooth h o r i z o n t a l w a t e r - c o o l e d c o p per surface,  and t h e t o p was a removable e l e c t r i c a l l y heated  copper s u r f a c e .  The l i q u i d to be t e s t e d was p l a c e d i n t h e  c o n t a i n e r and the h e a t e r l o w e r e d , f o r c i n g any excess out an o v e r f l o w  liquid  tube.  Calorimeters:  The bottom s u r f a c e c o n s i s t e d o f a t e s t  c a l o r i m e t e r surrounded by a guard r i n g c a l o r i m e t e r .  The t e s t  c a l o r i m e t e r was made o f a d i s c o f copper a p p r o x i m a t e l y 6.98 i n d i a m e t e r and .794 groove .476  cm.  ©m. t h i c k , i n t o w h i c h a c o n t i n u o u s s p i r a l  cm. by .476  cm. had been c u t .  A f l a t copper  plate  1  .159  ©ni. t h i c k was s o l d e r e d o v e r the bottom and b r a s s T*s were  s o l d e r e d o v e r an i n l e t and o u t l e t f o r t h e c o o l i n g w a t e r . s i d e o u t l e t on t h e T was used as a thermocouple  well.  The guard r i n g c a l o r i m e t e r was made o f a .159 a n n u l a r copper p l a t e w i t h i n s i d e 7.31 13.3  cm. d i a m e t e r .  Copper t u b i n g .476  The  cm.  cm. d i a m e t e r and o u t s i d e cm. i n d i a m e t e r was  wound i n a t i g h t s p i r a l from i n s i d e t o o u t s i d e on one  surface  1. THERMOCOUPLE  SPRING  THERMOCOUPLE  2.  G L A S S  a  TRANS1TE  4.  WATER  ARRANGEMENT  GUIDES  CONTAINER  INLET5  5. G U A R D R I N G HEATER-COPPER 6. T E S T H E A T E R - C O P P E R 7  AND OUTLETS  JL  GUARD  8. T E S T  RING  CALORIMETER  CALORIMETER  - COPPER  - COPPER  Do-  i/ ^a ft -  ". kc -  FIG. 2  GENERAL  ASSEMBLY OF T E S T C E L L  o f t h e p l a t e , and s o l d e r e d i n p o s i t i o n .  B r a s s T ' s were  at-  t a c h e d a t the i n l e t and o u t l e t f o r w a t e r openings and thermocouple w e l l s .  The two c a l o r i m e t e r s were j o i n e d by g l y c e r i n e -  l i t h a r g e cement. Walls:  The t r a n s i t e p i p i n g used f o r t h e w a l l was  cm. o u t s i d e d i a m e t e r , 12.1 and 13.7 1.98  15*55  cm. i n s i d e d i a m e t e r a t the bottom,  cm. i n s i d e d i a m e t e r a t the t o p .  By c u t t i n g t h e p i p e  cm. below t h i s change i n d i a m e t e r on t h e s m a l l e r s i d e , a  c o n t a i n e r o f the d e s i r e d c a p a c i t y and a c o n v e n i e n t s u p p o r t  for  t h e removable h e a t e r were o b t a i n e d .  cm.  H o r i z o n t a l h o l e s .318  d i a m e t e r were d r i l l e d a t o p p o s i t e s i d e s o f t h e c o n t a i n e r  at  each o f t h r e e e q u a l l y spaced l e v e l s between bottom and t o p . G l a s s t u b e s , w h i c h were f a s t e n e d w i t h p l a s t i c wood i n t o t h e s e h o l e s , p r o v i d e d a g u i d e f o r thermocouples m e a s u r i n g t h e temperature gradient w i t h i n the l i q u i d .  The c a l o r i m e t e r was  f a s t e n e d t o t h e t r a n s i t s w i t h L e Pages g l u e and l i t h a r g e g l y c e r i n e cement. .1^9  A copper o v e r f l o w tube was i n s e r t e d about  oia. above the t o p o f the  container.  Heaters The t o p s u r f a c e o o n s i s t e d o f a guard and t e s t h e a t e r t h e same s i z e as t h e c a l o r i m e t e r s . .476  The copper was  cm. t h i c k w i t h a narrow f l a n g e on i n n e r and o u t e r edges  making t h e edges .955 cm. t h i c k . ed w i t h g l y c e r i n e - l i t h a r g e cement.  The two h e a t e r s were  fasten-  Heat was p r o v i d e d f o r t h e  t e s t h e a t e r by a 25 ohm p i e c e o f nichrome r i b b o n w i r e wound u n i f o r m l y o v e r m i c a , and f o r t h e guard r i n g by a 55 ohm p i e c e wound s i m i l a r l y .  G l y p t a l and a s h e e t o f m i c a i n s u l a t e d the  8. h e a t i n g elements from the c o p p e r .  The n i chrome ends were  f a s t e n e d t o b i n d i n g p o s t s screwed t o a t h i n p i e c e o f board p l a c e d o v e r the two h e a t e r s .  transits  A thin steel cylinder  1 2 . 7 cm. h i g h was f a s t e n e d a t t h e bottom around t h e h e a t e r and packed w i t h r o c k wool i n s u l a t i o n .  The h e a t e r s c o u l d t h e n  be r a i s e d o r l o w e r e d onto the s u r f a c e o f t h e l i q u i d  under  test. The complete c e l l was p l a c e d a t the c e n t r e o f a 2 0 . j> can. by 4^.7 cm. d i a m e t e r s t e e l drum and packed u n d e r n e a t h w i t h 8j?% magnesia and around t h e s i d e s w i t h r o c k w o o l as shown i n f i g u r e 2 .  Temperature Measurements A l l temperatures  were measured by thermocouples  made from jf^O B . and S. gauge c o p e l and copper j u n c t i o n s .  B . and S.  gauge  A C a l i b r a t i o n c u r v e f o r the s i n g l e j u n c -  t i o n was drawn u s i n g r e s u l t s o b t a i n e d by comparing r e a d i n g s o f the C o p p e r - C o p e l those o f a s t a n d a r d C o p p e r - C o n s t a n t a n j u n c t i o n a t t h e same t e m p e r a t u r e .  The c u r v e was checked a t  t h e steam p o i n t and a t t h e benzene b o i l i n g p o i n t . I n l e t and o u t l e t temperatures  o f the c a l o r i m e t e r  w a t e r were measured by f o u r - j u n c t i o n t h e r m o p i l e s w h i c h were checked a g a i n s t a c a l i b r a t e d s i n g l e j u n c t i o n t h e r m o c o u p l e . The c o l d j u n c t i o n s were k e p t a t 0°G i n c r u s h e d i c e and i n no case was a common c o l d j u n c t i o n u s e d .  The thermo-  N  c o u p l e l e a d s were brought t o a u n i f o r m t e m p e r a t u r e * zone box and from t h e r e t h r o u g h #18 Copper l e a d s t o a r e v e r s i n g s w i t c h .  COLD  JUNCTION  HOT J U N C T I O N  REVERSING  SWITCH  POTENTIOMETER  FIG. 3  THERMOCOUPLE  CIRCUIT  9. T h i s s w i t c h , as shown i n f i g u r e 3 , r e v e r s e d t h e d i r e c t i o n ' o f the E . M . F . through a l l connections t o the potentiometer.  By  a v e r a g i n g b o t h r e a d i n g s , any s t r a y emf»s a r i s i n g i n t h a t  part  o f the c i r c u i t were e l i m i n a t e d .  Copper t o copper c o n t a c t s  were used t h r o u g h o u t . The p o t e n t i a l s were measured w i t h a Leeds and N o r t h r u p p o t e n t i o m e t e r N o . 8662 where emf*s c o u l d be e s t i m a t e d t o one m i c r o v o l t .  S i n c e the c o p p e r - c o p e l j u n c t i o n gave a p -  p r o x i m a t e l y a 40 m i c r o v o l t change p e r d e g r e e ,  i t was thought  temperatures were a c c u r a t e a t l e a s t t o 0 . 1 ° C f o r t h e s i n g l e j u n c t i o n and 0 . 0 1 ° G f o r t h e t h e r m o p i l e .  P o s i t i o n o f Thermocouples The p o s i t i o n o f a l l thermocouples i s shown i n figure 4. F i v e thermocouples were p l a c e d i n t h e same r e l a t i v e p o s i t i o n i n b o t h t h e h e a t e r and c a l o r i m e t e r s u r f a c e s .  The  t e s t s u r f a c e s had t h r e e j u n c t i o n s spaced u n i f o r m l y o v e r t h e area.  They were i n s e r t e d i n h o l e s d r i l l e d p a r a l l e l t o and  j u s t beneath the s u r f a c e .  The j u n c t i o n was brought t o  s u r f a c e and s o l d e r e d i n t h e d e s i r e d p o s i t i o n .  The guard  r i n g s each had two thermocouples spaced 1 8 0 ° a p a r t , j u s t beneath t h e s u r f a c e .  the  inserted  A l l thermocouples i n the h e a t e r  were c a r e f u l l y e l e c t r i c a l l y i n s u l a t e d . The temperature w i t h i n t h e l i q u i d was measured a t different  l e v e l s by t h r e e e q u a l l y spaced thermocouples g u i d e d  by t h i n g l a s s tubes shown i n f i g u r e 2 .  The i n d i v i d u a l thermo-  c o u p l e l e a d s were t h e n f a s t e n e d t o a moveable b r a s s s l i d e r  FIG. 4  THERMOCOUPLE  POSITIONS  10. r e s t i n g on a weak c o m p r e s s i o n s p r i n g which was f i x e d a t l o w e r end.  its  By f i x i n g the thermocouples i n p o s i t i o n w i t h  the  s p r i n g s under s l i g h t c o m p r e s s i o n , any e x p a n s i b n o f t h e w i r e caused by h e a t i n g was overcome and the j u n c t i o n s were h e l d without sagging at a l l times.  Water Supply Constant t e m p e r a t u r e and c o n s t a n t was s u p p l i e d by a c o n t a i n e r p l a c e d 4 f t . ©ell.  pressure water  6 i n . above t h e  test  Constant l e v e l wars- o b t a i n e d by u s i n g a c e n t r a l o v e r The w a t e r was heated by a v a r i a b l e 0-500 watt,  flow tube.  h e a t e r supplemented by two t h e r m o s t a t i c a l l y c o n t r o l l e d k n i f e heaters. constant  A vapour p r e s s u r e t h e r m o s t a t kept the t e m p e r a t u r e to  0.05°C.  Heating C i r c u i t The h e a t i n g c i r c u i t i s shown i n f i g u r e 5« was s u p p l i e d toy 12- and 4 0 - v o l t s t o r a g e b a t t e r i e s .  Current The  s w i t c h i n g arrangement  enabled c u r r e n t i n b o t h c i r c u i t s t o be  r e a d on one ammeter.  Both heaters operated at a l l times  whether the ammeter was i n o r out o f t h e c i r c u i t .  PROCEDURE A f t e r the b a t h h e a t e r and s t i r r e r had been the t e s t c e l l was f i l l e d  to the overflow tube.  started,  The l i q u i d  b e i n g t e s t e d had been heated above any t e s t temperature t o d r i v e out d i s s o l v e d g a s e s .  The h e a t e r was t h e n l o w e r e d ,  f o r c i n g t h e excess l i q u i d out the o v e r f l o w t u b e .  11. The o u r r e n t  was s w i t c h e d on and a d j u s t e d i n t h e c e n t r e and guard r i n g u n t i l t h e d e s i r e d temperature was o b t a i n e d a t b o t h h e a t i n g surfaces.  The w a t e r f l o w i n g t h r o u g h t h e c a l o r i m e t e r was a d -  j u s t e d u n t i l the bottom s u r f a c e t e m p e r a t u r e s were u n i f o r m . About 4 t o 6 hours were r e q u i r e d t o a t t a i n brium.  equili-  A f t e r one hour a t e q u i l i b r i u m r e a d i n g s were r e c o r d e d .  The t h e r m o p i l e s were r e a d e v e r y 10 minutes f o r one hour and t h e water r a t e was checked e v e r y lj> m i n u t e s . t o make s u r e was c o n s t a n t .  it  The r a t e was measured by c o l l e c t i n g t h e w a t e r  i n a graduated c y l i n d e r f o r a p e r i o d of f i v e minutes.  RESULTS Theory o f Measurement The t h e r m a l c o n d u c t i v i t y was d e t e r m i n e d from  the  steady s t a t e equation  K » SkSL. £ - the heat f l o w .  T h i s was found by m e a s u r i n g the r a t e o f  f l o w o f w a t e r t h r o u g h t h e t e s t c a l o r i m e t e r and the i n l e t and o u t l e t temperature o f the w a t e r .  The average d i f f e r e n c e o v e r  one hour was t a k e n as the temperature  difference.  /AX - t h e d i s t a n o e between t h e two s u r f a c e s o r two o f t h e thermocouples s t r e t c h e d t h r o u g h the l i q u i d .  These d i s t a n c e s  were measured by a d e p t h guage. A T - the temperature d i f f e r e n c e between the two p o i n t s i n question.  12.  A - the area o f t e s t c a l o r i m e t e r  The Thermal C o n d u c t i v i t y o f Water To t e s t t h e a p p a r a t u s i t was d e c i d e d t o measure t h e thermal c o n d u c t i v i t y o f d i s t i l l e d water.  The v a l u e f o r w a t e r  has been o b t a i n e d by a number o f i n v e s t i g a t o r s and i n r e c e n t y e a r s i t s v a l u e has been f a i r l y w e l l e s t a b l i s h e d .  The f o l -  l o w i n g t a b l e g i v e s some o f t h e l a t e r v a l u e s o b t a i n e d . Observer  Year  Kc a t  30°C  (Gal °C-1 Cm- ) 1  1920  .00144  Bridgeman  1923  .00144  Davis  1924  .00146  Kaye and Higgins  1928  .00151  Smith  1930  .00144  Bates  1936  .00145  Jakob  1 0  1 1  The f o l l o w i n g d a t a and r e s u l t s were o b t a i n e d f o r water.  The a r e a o f t h e c a l o r i m e t e r was, 37*66 s q . cms. The  d i s t a n c e between t h e thermocouples was # 1  t o #11 = 1 . 2 0 1 cms.  # 1  t o #18 -  .546  cms.  #18  t o #11 »  .655  cms.  The t r u e t h e r m a l c o n d u c t i v i t y was found by u s i n g ,=the d i s t a n c e between thermocouples #1 t o # 1 1 . 1 0  1 1  A n n . P h y s i k . 6 3 , 537 (1920) E h i l . Mag. 4 7 , 922 (1924)  Justification  13. for using the distance between thermocouples i s shown i n the  i  graph of the temperature gradient through the liquid (Fig. 6). A typical data sheet for water follows: Date: Start: Time TC#  June 26, 1946. 12:00 A.M.  2.00 1556  1 2 3 4 3  1752  1748 730 730  18  1294  7  753 1748  8  9 10 11 12 15  742  1749 970  1740  Current C (amps) Gr Volts  736 .220 .610  431  3.00 1577 1775 1772 730 730  4.00 1587 1784 1783 736 736  5.00 1595 1792 1790 736 736  5.30 1598 1806 1803 734 734  730 1771 746 1771 974 1762 738 .220 .610 43JL  738 1782  739 1790 750 1790 979 1781 739 .219 .610  739  1312  1305  742  1781 977 1773 732 .220  .610 430  1316  1318  1800  744  1800  978 1790 736 .219  43LO  Thermopile readings and water rate. Time (Minutes) 0 10 20 30 40 50 60  70 80 90  100 110 120  1+* #13  #16 2846 2844  2950 2948 2939 2948 2950 2948 2953 2964 2961 2960 2962 2961 2960  2837  2838 2851 2851 2828 2855 2844 2841 2840 2841 2841  WR cc/10 m.  612 612 612  612 612  Calculation of Thermal Conductivity A AT  A - 37.66 sq. cm.  .610  43.0  Run #7  7.30 1599 1809  microdot* M  1812  731 731 1320 733 1810 743 1800  978 1799 752 .219 .610 4^0  •»  %•  n H  11 U  11 M  r •1  14. AX -  1.201  s q . cm.  ( D i s t a n c e between #1 and  ^T -  1.598  #11)  - . 9 7 8 - 620 m i c r o v o l t s -  Q - Average #13  '»  °C.  15.50  2.953.3  #16 2.842.9  " D i f f e r e n c e « 111.4 Water r a t e = 6.13 c o / m i n .  microvolts  » 111*1 i i l 2 l m . 7 1 1 c a l s / s e c .  160 (600) K = .711 (1.201) 37.66 (15.50) at  32.8  .  >  0  0  1  4  cals  6  om. °0 s e c .  °C  For various temperatures, the r e s u l t s given i n the f o l l o w i n g t a b l e were o b t a i n e d : Run No.  5  7 8 9  Top Surface Temp. °C •  315 45L6 5512  432  AT  cms.  Heat Flow  A cm  AT  °C  2  Cals/sec  1201 1201 1201 IL201  .456  9.74  -711  15^0  •579  12^5  1138  37.66 3*66 37.66 37.66  2£L4  E eal/cm-°Csec  .00143 .00146 .00145 .00146  Temp o f reading °C  212 328  39-3  29.6  A comparison o f B a t e s ' v a l u e s with, t h e s e a t t h e same temperature i s g i v e n i n t h e n e x t  KQ  Temp.  B a t e s KQ  27.00143  30 33 39  table.  .00146 .00146 .00145  .00144  .00145 -00146 -00148  C o n s i d e r i n g how o l o s e t h e t e m p e r a t u r e s c o u l d be r e a d and v a r i e t y o f r e s u l t s  o b t a i n e d by o t h e r  i t was d e c i d e d t h a t the above r e s u l t s  investigators,  showed t h a t t h e a p -  15. paratus was satisfactory for measuring the thermal conductivities of liquids. The Thermal Conductivities of the Deoahydranapthalenes Preparation of Materials The separation of decalin into its cis and trans isomers was done by rectification in a Stedman column at 9 mm. pressure.^ about  2  The purest fraction of each isomer from this was  99.5%.  The purest fraction of the cis isomer was then further purified by successive recrystallization in a dry ice bath using the method of Seyer and Walker. ^ After re1  peated crystallization a constant value for the freezing point of - 4-5• 31 was obtained.  This was considered to be  the purest sample of cis decalin available. In a similar manner the trans isomer was recrystallized until a constant freezing point of - 30.76 was obtained. These samples^were then used for the measurements. Trans Deoahydranapthalene The following are the results for the thermal conductivity of trans decahydranapthalene.  A data sheet and  calculations are followed by a table of values.  Figure 7  shows the variance of thermal conductivity with temperature.  Angley Potkins and Rush - Bachelor Thesis 1942. ^ J . A . C . S . 6 0 , 2125 (1938)  i<:  16. Date: Start: Time TC#  Current (amps) Volts  July 12, 1946 11:30 A.M. 1 2 3 4 5 18 7 8 9 10 11 12 15  C G  Run #22  2,00  4.00  5.00  5.30  6.00  1642 1888 1916 710 . 710 1344 711 1915 734 1915 1011 1881 726 .115 -502  1691 1946 1975 712 712 1366 712 1975 735 1975 1022 1932 726 •115 .502  1700 1953 1982 714 1375 715 1981 738 1981  1701 1954 1982 715 714 1375 715 1982 738 1982  1702 1956 1984 712 712 1376 712 1984 736  1943 750 .115 .502  42  42  730 .115 .502  Time (Minutes) 0 10 20 30 40 50  60  714  1024  2811 2819 2816 2814 2814 2818  2860 2857  ,  2811  1945 726 .115 .502  42  #15 2857 2859 2858 2857  #16  1984 1024  1024 1943  42  Wn'ovol*!  42 WR  co/5 m. 261 261  2858  Calculations: A « 37*66 sq. cm. AX » 1.222 cm. AT  »  1*701  -  1.024  .  l  6  #  7  o  4  C  40 q  « 2.8^8  --2.81? 160  12611 . (300)  K - »2?4 (1.222) „-  #  37.66 (16.74)  0  0  0  4  ^  .234  cals/sec  oal cm - sec °C  at 35.8 °C The following results were obtained for various temperatures.  17. Run No.  15 16 18 19 21 22  25  Top Surface Temp. °G 37.2  255  5o\8  253  247 495 82. o Cis  AS cms.  Heat Flow  i£T °C  A cm2  Temp o f reading °G  K cal/cm-°G -36©  S  cals/sec  1222 1222 1222 1222 1222 1222 1222  .1366  .0464 •309 .0558 .0487 .234 .647  10.71 37*66 .000413  310  2195  388  £33  3-75 £25  16.74  39,40  37-66 3^66 37.66 31166 3746 37.66  217  .000454 .000457 .000483 .000484 .000455  216  214 358  •000534  33L6  Decahydranapthalene The f o l l o w i n g a r e t h e r e s u l t s f o r the^ t h e r m a l c o n -  d u c t i v i t y o f c i s decahydranapthalene.  A d a t a sheet and c a l  c u l a t i o n a r e f o l l o w e d by a t a b l e o f v a l u e s . the variance o f thermal c o n d u c t i v i t y w i t h D a t e : J u l y 16, 1946 S t a r t : 11:00 P . M . J u l y 15 Time 9.00 TG#  Current Volts  1 2 3 4 5 187 8 9 10 11 12 15 C G  880 970 981 692 708 832 710 981 714 983 761 970 714  -056 .225 13  F i g u r e 8 shows temperature. Run #31  9.30 880 972 981 692 710 833 710 982 715 984 762 971 714 .056 -225 13  10.00 882 973 983 695 710 833 710 983 715 986 770 971 715 .056 .225 13  10.30 888 973 985 695 710 841  710 985 716 988 769 974 715 .056 .225 13  If  H H •1  Ik If *M It la  to •1  U  18.  Time Minutes  Outlet  5  2832 2828  25  2830 2832 2832  0  Inlet  2816 2819  2828  10 15 20  35 40 45 50  55 60  Ave.  2816 2819  202  2818  204  2815 2819  2834 2834 2836 2832 2832 2831 2831  50  WR cc/5 min.  2818 2818  2817  203  2817.5  203  2817 2818 2818  283L7  Calculations: A " 37*66 sq.. cms.  A X = 1 . 2 2 2 cms. AT  - 885 - 767  40  2.95°C  m  q, m 142 (20?) • , 160 ( 3 0 0 )  K  w 0  m .0601 (1.222)  6oi  m  cals/sec.  cals om - s e c ' C  ,000656  37*66 ( 2 . 9 5 ) at  21.2°C  The f o l l o w i n g r e s u l t s were o b t a i n e d a t v a r i o u s temperatures. Run No. _ ,  26 28 29 30 31 32  33  Top Surface Temp. °G 52J. 519 510  7&\6  253 35B  411  AX cms.  Heat Flow  AT °C  A  cm.2  %  Cals/seo .670 .670 1222 1222 1222 1222 .670  .371 .301 .359  ,671 .060 .407 .229  780 ao3 15.06 36.95 295 2110 5-71  37.66 37.66 37.66 37.66 37-66  3^66  K cals cm-sec °C .000724 .000660 .000775  .OOO656  .0OO656  .000624  37.66 .000712  Temp o f reading O Q  319  302  354 528 212 374 31-9  19. Explanation of Results The reasons f o r the e r r a t i c r e s u l t s o b t a i n e d f o r t h e t h e r m a l c o n d u c t i v i t y o f t h e decahydranapthalenes as  may be  follows: 1. Leakage o f the c o n t a i n e r .  G r e a t d i f f i c u l t y was  encountered i n making the c o n t a i n e r i m p e r v i o u s t o d e o a l i n . To p r e v e n t l e a k a g e the whole o f t h e i n s i d e o f t h e  oontainer  was c o v e r e d w i t h "Cenoo" l a b e l v a r n i s h w h i c h was s a t i s f a c t o r y f o r two o r t h r e e runs but e x t r a c o s t s were t h e n r e q u i r e d . The l a b e l v a r n i s h d e c r e a s e d t h e c o n d u c t i v i t y o f the  bottom  metal surfaces which r e s u l t e d i n a longer time being necessary to reach e q u i l i b r i u m .  The l a b e l v a r n i s h a l s o i n c r e a s e d  the l i k e l i h o o d o f heat l o s s down t h r o u g h t h e t r a n s i t s  to  the  bottom s u r f a c e . 2 . The i n l e t t h e r m o p i l e #16 s t a r t e d t o r e a d t o o high.  T h i s was p r o b a b l y because heat was conducted a l o n g t h e  t h e r m o p i l e from t h e o u t s i d e o r because t h e t h e r m o p i l e was t o u c h i n g the m e t a l i n t h e t e e .  The t h e r m o p i l e was removed  and an attempt was made t o f i x i t but a f t e r a few runs  it  again read h i g h .  i t was  Thus t o o b t a i n t h e i n l e t temperature  n e c e s s a r y t o remove the h e a t e r and r u n t h e w a t e r t h r o u g h as f a s t as p o s s i b l e and t h u s be unable t o p i c k up any h e a t . was t h e n r e a d and t h i s gave t h e i n l e t temperature  #13  of the water.  T h i s was not c o m p l e t e l y s a t i s f a c t o r y as i t d i d not g i v e t h e i n l e t temperature  a t t h e same t i m e as t h e o u t l e t  temperature.  The o b t a i n i n g o f a h i g h e r t h e r m a l c o n d u c t i v i t y f o r t h e c i s isomer as oompared w i t h the t r a n s i s o m e r i s t o be e x -  20.  pected.  T h i s c i s f o r m has a h i g h e r d e n s i t y , i . e . the m o l e -  c u l e s are c l o s e r together, transfer  and t h u s i t s h o u l d be a b l e  to  heat more r e a d i l y .  SUGGESTIONS FOR FUTURE OPERATION 07 APPARATUS Connections One o f the main d i f f i c u l t i e s  i n t h i s experiment was  k e e p i n g the l i q u i d s from p e n e t r a t i n g the cements used t o f a s t e n the c e l l t o g e t h e r .  Over t h e p e r i o d o f t i m e  necessary  f o r e q u i l i b r i u m , d e c a l i n would seep t h r o u g h g l y c e r i n e - l i t h a r g e cement.  G l y p t a l and o t h e r p a t e n t o r g a n i c p r o t e c t i v e  are quite s o l u b l e i n c i s decahydranaphthalene.  coatings  L e Pages g l u e  i s s o l u b l e i n d e c a l i n u n l e s s baked a t 100°C f o r two hours o r more. softens  "Genco" l a b e l v a r n i s h i s r e s i s t a n t a t about 80°G.  t o d e c a l i n but  I t i s too t h i n t o be o f any use i n  j o i n i n g two p i e c e s o f m e t a l , o r m e t a l and t r a n s i t s , be used t o coat a more p r e v i o u s but r i g i d  but can  cement.  The two b e s t cements found f o r t h e j o b were W&ldwood P l a s t i c R e s i n and S a u r e i s i n L i q u i d P o r c e l i n . only useful i n t h i n l a y e r s .  The S a u r i e s e n i s  The Wfeldwood i s u s e f u l i n t h i n  c o a t i n g s o r t h i c k l a y e r s and i s t h e r e f o r e t o use f o r j o i n i n g t h e p a r t s o f the Before f u r t h e r measurements  t h e most c o n v e n i e n t  cell. are attempted,  suggested t h a t the c a l o r i m e t e r be s e p a r a t e d and t h e g l a s s thermocouple tubes removed.  from t h e After  it  is  transits  careful  c l e a n i n g , the p a r t s s h o u l d be r e a s s e m b l e d u s i n g Wfeldwood f o r  a l l connections.  The g l a s s tubes s h o u l d be r e i n s e r t e d  f i x e d w i t h Wfcldwood.  and  A t l e a s t f o u r days s h o u l d be a l l o w e d f o r  the cement t o harden u n l e s s t h e l a y e r i s v e r y t h i n , when two days w i l l be  sufficient.  Thermopiles Some d i f f i c u l t y was encountered readings  i n getting  o f the w a t e r i n l e t t e m p e r a t u r e t o the  I t was a t f i r s t f e l t  true  calorimeter.  t h a t the i n s u l a t i o n had f a i l e d  metal to metal contact  causing  o f the b r a s s and the t h e r m o p i l e  e v e r , e x a m i n a t i o n r e v e a l e d no f l a w s i n the i n s u l a t i o n . t h e t h e r m o p i l e l e a d s were o n l y immersed i n the w a t e r  r  howSinoe  about  h a l f an i n c h at the hot j u n c t i o n , i t was thought some heat might have been conducted a l o n g the w i r e s t o t h e c a u s i n g too h i g h a t e m p e r a t u r e t o be It  junction  read.  i s s u g g e s t e d t h a t the p o s i t i o n o f the  thermopile  hot j u n c t i o n s be changed so t h a t the i n c o m i n g and o u t g o i n g w a t e r f l o w s over at l e a s t s i x i n c h e s o f the l e a d w i r e s i m m e d i a t e l y p r e c e d i n g the  junctions.  I f the l e a d w i r e s were  encased i n a t h i n g l a s s tube w i t h o n l y the free stream,  j u n c t i o n i n the  a minimum r e s i s t a n c e would be o f f e r e d t o  f l o w o f the l i q u i d p a s t the w i r e s .  the  The j u n c t i o n s h o u l d be  i n s u l a t e d so t h e r e i s no p o s s i b l e chance o f c o n t a c t  between  the j u n c t i o n and the b r a s s c o n n e c t i o n .  Container . C o n s i d e r a b l e d i f f i c u l t y was e x p e r i e n c e d i n the c e l l t o the w a t e r p i p e c o n n e c t i o n s owing t o the  fixing inacces-  22. s a b i l i t y of the c o n n e c t i o n s .  I t i s suggested t h a t a l a r g e *  window be c u t i n the o u t s i d e m e t a l c o n t a i n e r t o improve v i s i b i l i t y when w o r k i n g around the c e l l when i t i s i n p o s i t i o n .  SUGGESTIONS FOR FUTURE RESEARCH The a p p a r a t u s s h o u l d , w i t h m i n o r a d j u s t m e n t s ,  enable  t h e t h e r m a l c o n d u c t i v i t i e s o f v a r i o u s l i q u i d hydrocarbons t o be measured.  There i s need o f c o n s i d e r a b l e work i n t h i s  field  as v e r y l i t t l e has been done. The t h e r m a l c o n d u c t i v i t y o f the c i s and t r a n s i s o m e r s o f v a r i o u s o t h e r o r g a n i c compounds c o u l d a l s o be i n v e s t i g a t e d t o see whether o r not the c i s isomer has a h i g h e r c o n d u c t i v i t y i n every c a s e .  CONCLUSION An a p p a r a t u s f o r measuring the t h e r m a l c o n d u c t i v i t y o f l i q u i d s has been b u i l t .  I t was found t o work s a t i s f a c -  t o r i l y by t e s t i n g i t w i t h d i s t i l l e d w a t e r , t h e t h e r m a l c o n d u c t i v i t y o f w h i c h had been determined p r e v i o u s l y by a number Of i n v e s t i g a t o r s .  The t h e r m a l c o n d u c t i v i t i e s o f t h e c i s and  t r a n s isomers o f decahydranaphthalene  were a l s o measured.  A l t h o u g h somewhat e r r a t i c r e s u l t s were o b t a i n e d f o r t h e s e compounds i t was found t h a t i n a l l c a s e s t h e c i s i s o m e r had a h i g h e r t h e r m a l c o n d u c t i v i t y t h a n the t r a n s i s o m e r .  With  t h i s a p p a r a t u s c o n s i d e r a b l y more i n v e s t i g a t i o n s can be c a r r i e d out p o s s i b l y a l o n g the, l i n e s  suggested.  

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