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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 . Robinson A Thes i s submit ted i n P a r t i a l F u l f i l m e n t o f the Requirements f o r the Degree o f MASTER OF APPLIED SCIENCE i n the Department o f CHEMICAL ENGINEERING The U n i v e r s i t y o f B r i t i s h Columbia J u l y , 1946. ACKNOWLEDGEMENT The author wishes to acknowledge the 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 ou t . He wishes to acknowledge the adv ice and sugges t ions g iven by D r . W. E . Seyer , 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 . I n t r o d u c t i o n 1 I I . 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. Genera l 2 2. I n L i q u i d s 2 C. The Method Used 5 I I I . D e s c r i p t i o n o f Apparatus 6 A . The Test C e l l 6 1. C a l o r i m e t e r s 6 2 . W a l l s 1 B . The Heaters 7 C. Temperature Measurements 8 D. P o s i t i o n o f Thermocouples 9 E . Water Supply 10 F . Hea t ing C i r c u i t 10 I V . Procedure 10 V . R e s u l t s 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 15 1. P r e p a r a t i o n o f M a t e r i a l s 15 2. Trans Deoahydranapthalene 15 3. G i s Decahydranapthalene 17 4. E x p l a n a t i o n o f R e s u l t s 19 TABLE OF CONTENTS (Con t ' d ) Page V I . Suggest ions f o r Future Opera t ion o f the Apparatus 20 A . Connections 20 B . Thermopiles 21 G. Con ta ine r 21 V I I . Suggest ions f o r Future Research 22 V I I I . C o n c l u s i o n 22 1 THE THERMAL CONDUCTIVITIES OF CIS AND TRANS DECAHYDRANAPTHALENE INTRODUCTION A knowledge o f the thermal 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 de s ign o f heat t r a n s f e r equipment and i n the compounding o f l u b r i c a t i n g o i l s . 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 to determine the 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 or by s imple v i b r a t i o n s . Thus our problem has two purposes ; f i r s t , to b u i l d an apparatus f o r measuring the thermal 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 and second, to cont inue the i n -v e s t i g a t i o n s a l r eady made i n t h i s l a b o r a t o r y on the p h y s i c a l p r o p e r t i e s o f ©is and t r ans decahydranapthalene. THE THERMAL CONDUCTIVITIES OF LIQUIDS Theory The thermal c o n d u c t i v i t y " K " o f a substance i s a measure o f the heat t r a n s f e r through the substance due to conduc t ion . I t i s best de f ined by the F o u r i e r e q u a t i o n . Consider a s m a l l a rea dA i n the m a t e r i a l whose thermal con -2. d u c t i v i t y i s r e q u i r e d . I f < | f i i s the temperature g r ad i en t normal to dA i n the d i r e c t i o n x , then the q u a n t i t y o f heat dQ, f l o w i n g through dA i n u n i t t ime dt i s g i v e n by: dQ, = K dA o x I n the s teady s t a t e o f heat f l o w . t h e e q u a t i o n be-comes Q, » K A /S, P C For l i q u i d s i n p a r t i c u l a r , Br idgeman 1 has worked out a t h e o r e t i c a l equa t ion which checks f a i r l y w e l l w i t h ex-pe r imen ta l , da t a . S m i t h 2 has used d imens iona l a n a l y s i s to ob-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 ha t show good agreement w i t h experiment . However, these equat ions can be used o n l y as approx imat ions . Measurement D i f f i c u l t i e s G e n e r a l : The thermal c o n d u c t i v i t y o f any substance i s cons ide red t o be one o f the more d i f f i c u l t p h y s i c a l cons tants t o measure w i t h any degree o f accuracy . One o f the main r e -asons f o r t h i s i s the non-ex i s tance o f an i n s u l a t o r i n the e l e c t r i c a l sense tha t would enable heat f l o w to be d i r e c t e d i n any d e s i r e d channe l . A l s o the re i s not the ins tantaneous a t ta inment o f e q u i l i b r i u m tha t the re i s i n an e l e c t r i c a l system. I n L i q u i d s : The main problem i s to prevent heat t r a n s -f e r by oonvec t i on . T h i s i s accomplished i n d i f f e r e n t ways, depending on the method used. 1 P r o c . Am. Acad . A r t and S c i . 59 No. 7 141 (#23) 2 I n d . and'Eng. Chem. 23, 416 (1931) 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 are encountered i n these methods and u s u a l l y s e v e r a l approximat ions t ha t can not always be j u s t i f i e d a re r e q u i r e d . Hence i n recent years no at tempts have been made to use f low methods. Most i n v e s t i g a t o r s have measured the thermal con-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 ing a t h i n f i l m o r a t h i c k d i s c . The thermal c o n d u c t i v i t y i s found from the steady s t a t e equa t ion (g iven under t h e o r y ) , a l l the o ther q u a n t i t i e s i n t h i s equa t ion be ing measurable . Two t y p i c a l examples o f t h i n f i l m methods are those of Kaye and Higgins-5 and Bridgeman^. Kaye and H i g g i n s 1 apparatus c o n s i s t e d o f an upper h e a t i n g b l o c k and a lower 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 aced between these two b l o o k s . A g a l l e y around the ou t s ide prevented o v e r f l o w . A guard heater above the hot b l o c k stopped heat from escap ing upwards and thus a l l the heat was t r a n s m i t t e d through the l i q u i d . The two b l o c k s were separated a known d i s tance , by three g l a s s rods* C o r r e c t i o n s were a p p l i e d by t e s t i n g the apparatus w i t h a m a t e r i a l o f known thermal c o n d u c t i v i t y . Another type o f f i l m apparatus was dev i sed by Bridgeman and used by Smith? and o t h e r s . T h i s method con-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 the l i q u i d be-? P h i l . T rans . Roy. Soc . 119, 110 (1902) 4 P h . Mag. 19, 587 (1910) SProc . Roy. Soc. (London) A117, 4-59 (1928) 6LOO. C i t . 7 I n d . and Eng . Chem. 22, 1246 (1930) 4. tween them. The i n t e r i o r of the cen t re 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 , the heat f l o w i n g r a d i a l l y outwards. The inpu t o f heat was obta ined by measuring the e l e c t r i c a l energy to the w i r e . The temperature d i f f e r e n c e was measured by thermocouples and the t h i c k n e s s of the f i l m was determined 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 the accuracy de-pended on some p rev ious measurement. The main drawbacks o f the 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 the t h i c k n e s s o f the f i l m (2) s m a l l temperature drop across the f i l m B a t e s 8 a p p a r a t u s i s the best example of the t h i c k d i s c method. I n t h i s method the l i q u i d i s heated from the top and coo led from the bottom and thus c o n v e c t i o n cu r r en t s are prevented . Ba t e s ' apparatus c o n s i s t e d of a c i r c u l a r con t a ine r the w a l l s o f which were made o f b a k e l i t e . The top was a cen t re hea ter and a guard heater i n s u l a t e d from each o the r . The bottom was s p i r a l f l ow water 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 . These were a l s o i n -s u l a t e d from eaoh o the r . Thus the l i q u i d i n the c o n t a i n e r was between two sur faces a known d i s t a n c e a p a r t . The guard r i n g s were so adjus ted tha t a uni form temperature e x i s t e d through h o r i z o n t a l p lanes i n the l i q u i d . The heat f l o w was measured by the s p i r a l f l o w water c a l o r i m e t e r , the area o f which had been determined p r e v i o u s l y . The temperature g r a -d i e n t through the l i q u i d was measured by thermocouples s t r e t c h e d h o r i z o n t a l l y through the l i q u i d . Thus a l l the 8 I n d . and Eng. Chem. 25, 431 (1933) 9 I n d . and Eng. Chem. 28, 494 (1936) terms i n the F o u r i e r equa t ion are known and the r e q u i r e d thermal 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 a r e : (1) I t does not. depend on the the rmooonduc t iv i ty o f some o ther l i q u i d used to c a l i b r a t e the appara tus . (2) The temperature g rad ien t through the f i l m can be ob-<X.fC t a i n e d and thus sur face e f f e c t s ' " e l i m i n a t e d . (3) I t does not r e q u i r e so accura te measurement o f the temperature d i f f e r e n c e as the f i l m method. The Method Used Our method was an adap t ion 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 . F i r s t , the amount o f hydrocarbon a v a i l a b l e was l i m i t e d . Thus i t was necessary to reduce the volume o f the c o n t a i n e r from 2000 co s . as i n Ba te s ' apparatus t o 250 c c s . i n our appara tus . Second, a new m a t e r i a l f o r the c o n t a i n e r had to be found as " d e e a l i n , | X a t t acks b a k i l i t e . I t was f i n a l l y dec ided to use a " t r a n s i t e " + con t a ine r s i n c e i t had a low thermal c o n d u c t i v i t y and was r e -s i s t a n t to d e c a l i n . A problem tha t arose was how t o a t t a c h the bottom c a l o r i m e t e r to the t r a n s i t s c o n t a i n e r . A f t e r ex-per iment ing w i t h numerous g lues and cements i t was dec ided to j o i n the two p a r t s toge the r w i t h "Lepages"^ g lue and cover the 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 an t to d e c a l i n . s Commercial name f o r a mix tu re o f c i s and t r ans decahydra-napthalene. * Trade name o f Johns M a n v i l l e L t d . * Trade name o f Le Page ' s I n c . 6. DESCRIPTION Off APPARATUS The equipment c o n s i s t e d of th ree main p a r t s ; a source o f water a t constant temperature and p ressu re , the t e s t c e l l i n i t s c o n t a i n e r , and a swi tohboard as shown i n f i g u r e 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 c o n s i s t e d of a sha l l ow c y l i n d r i c a l c o n t a i n e r approximate ly 2 cm. h i g h and 11.5 cm. i n d iamete r . The w a l l was t r a n s i t s p i p i n g , the bottom was a smooth h o r i z o n t a l wa t e r - coo l ed cop-per s u r f a c e , and the top 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 the con t a ine r and the hea ter lowered , f o r c i n g any excess l i q u i d out an over f l o w tube . C a l o r i m e t e r s : The bottom sur face 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 approximate ly 6.98 cm. i n diameter and .794 ©m. t h i c k , i n t o which a cont inuous s p i r a l groove .476 cm. by .476 cm. had been c u t . A f l a t copper p l a t e 1 .159 ©ni. t h i c k was so lde red over the bottom and brass T*s were so lde red over an i n l e t and o u t l e t f o r the c o o l i n g wate r . The s i d e o u t l e t on the T was used as a thermocouple w e l l . The guard r i n g c a l o r i m e t e r was made o f a .159 cm. annular copper p l a t e w i t h i n s i d e 7.31 cm. diameter and o u t s i d e 13.3 cm. d iameter . Copper t u b i n g .476 cm. i n diameter was wound i n a t i g h t s p i r a l from i n s i d e to o u t s i d e on one sur face 1. THERMOCOUPLE SPRING ARRANGEMENT 2 . G L A S S T H E R M O C O U P L E G U I D E S a T R A N S 1 T E C O N T A I N E R 4. WATER I N L E T 5 AND OUTLETS 5. G U A R D R I N G H E A T E R - C O P P E R 6. T E S T H E A T E R - C O P P E R 7 G U A R D RING C A L O R I M E T E R - C O P P E R 8. T E S T C A L O R I M E T E R - C O P P E R JL Do-i/- a^ ft ". kc -FIG. 2 GENERAL ASSEMBLY OF TEST CEL L o f the p l a t e , and so lde red i n p o s i t i o n . Brass T ' s were a t -tached a t the i n l e t and o u t l e t f o r water openings and thermo-couple 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. W a l l s : The t r a n s i t e p i p i n g used f o r the w a l l was 15*55 cm. o u t s i d e d iameter , 12.1 cm. i n s i d e diameter a t the bottom, and 13.7 cm. i n s i d e diameter a t the t o p . By c u t t i n g the p ipe 1.98 cm. below t h i s change i n diameter on the sma l l e r s i d e , a c o n t a i n e r of the d e s i r e d c a p a c i t y and a convenient support f o r the removable heater were o b t a i n e d . H o r i z o n t a l ho les .318 cm. diameter were d r i l l e d a t oppos i t e s i d e s o f the c o n t a i n e r a t each o f three e q u a l l y spaced l e v e l s between bottom and t o p . Glass tubes ,which were fas tened w i t h p l a s t i c wood i n t o these holes , p rov ided a guide f o r thermocouples measuring the tem-pera ture g rad ien t 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 fas tened t o the t r a n s i t s w i t h Le Pages g lue and l i t h a r g e -g l y c e r i n e cement. A copper ove r f low tube was i n s e r t e d about .1^ 9 oia. above the top o f the c o n t a i n e r . Heaters The top sur face o o n s i s t e d o f a guard and t e s t heater the same s i z e as the c a l o r i m e t e r s . The copper was .476 cm. t h i c k w i t h a narrow f l ange on i n n e r and outer edges making the edges .955 cm. t h i c k . The two heaters were f a s t e n -ed w i t h g l y c e r i n e - l i t h a r g e cement. Heat was p rov ided f o r the t e s t hea ter by a 25 ohm p i ece o f nichrome r i b b o n w i r e wound un i fo rmly over m i c a , and f o r the 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 sheet o f mica i n s u l a t e d the 8. h e a t i n g elements from the copper . The n i chrome ends were fas tened to b i n d i n g pos t s screwed to a t h i n p i e c e o f t r a n s i t s board p l a c e d over the two h e a t e r s . A t h i n s t e e l c y l i n d e r 12.7 cm. h i g h was fas tened a t the bottom around the hea te r and packed w i t h rock wool i n s u l a t i o n . The hea ters c o u l d then be r a i s e d or lowered onto the sur face o f the l i q u i d under t e s t . The complete c e l l was p l a c e d a t the cent re o f a 20. j> can. by 4^.7 cm. diameter s t e e l drum and packed under-neath w i t h 8j?% magnesia and around the s i d e s w i t h rock wool 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 B . and S. gauge copper j u n c t i o n s . A C a l i b r a t i o n curve f o r the s i n g l e j u n c -t i o n was drawn us ing r e s u l t s ob ta ined by comparing read ings o f the Copper-Copel those o f a s tandard Copper-Constantan j u n c t i o n a t the same temperature. The curve was checked a t the steam p o i n t and a t the 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 water were measured by f o u r - j u n c t i o n the rmopi les which were checked aga ins 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 thermocouple. The c o l d j u n c t i o n s were kept a t 0°G i n crushed i c e and i n no case was a common c o l d j u n c t i o n used. The thermo- N couple l eads were brought t o a uni form temperature* zone box and from there through #18 Copper l eads to a r e v e r s i n g s w i t c h . C O L D J U N C T I O N HOT J U N C T I O N R E V E R S I N G S W I T C H P O T E N T I O M E T E R 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 eve r sed the d i r e c t i o n ' o f the E . M . F . through a l l connect ions t o the po ten t iomete r . By averag ing both 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 ha t pa r t o f the c i r c u i t were e l i m i n a t e d . Copper to copper c o n t a c t s were used throughout . The p o t e n t i a l s were measured w i t h a Leeds and N o r -thrup potent iometer No. 8662 where emf*s c o u l d be es t imated to one m i c r o v o l t . S ince the copper -cope l j u n c t i o n gave ap-p rox ima te ly a 40 m i c r o v o l t change per degree, i t was thought temperatures were accura te a t l e a s t to 0 . 1 ° C f o r the s i n g l e j u n c t i o n and 0.01°G f o r the 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 f i g u r e 4 . F i v e thermocouples were p l a c e d i n the same r e l a t i v e p o s i t i o n i n both the heater 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 sur faces had three j u n c t i o n s spaced un i fo rmly over the a r e a . They were i n s e r t e d i n ho les 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 to the sur face and so lde red i n the 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 180° a p a r t , i n s e r t e d j u s t beneath the s u r f a c e . A l l thermocouples i n the hea te 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 the l i q u i d was measured a t d i f f e r e n t l e v e l s by th ree e q u a l l y spaced thermocouples guided 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-couple l eads were then fas tened to a moveable brass s l i d e r FIG. 4 T H E R M O C O U P L E P O S I T I O N S 10. r e s t i n g on a weak compression s p r i n g which was f i x e d a t i t s lower end. By f i x i n g the thermocouples i n p o s i t i o n w i t h the sp r ings under s l i g h t compress ion, any expansibn of the w i r e caused by hea t ing was overcome and the j u n c t i o n s were h e l d wi thou t sagging a t a l l t imes . Water Supply Constant temperature and constant p ressure water 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 . 6 i n . above the t e s t © e l l . Constant l e v e l wars- ob ta ined by u s i n g a c e n t r a l ove r -f l o w tube . The water was heated by a v a r i a b l e 0-500 watt, heater 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 hea t e r s . A vapour pressure thermostat kept the temperature constant to 0.05°C. Hea t ing 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« Cur ren t was s u p p l i e d toy 12- and 4 0 - v o l t s torage b a t t e r i e s . The s w i t c h i n g arrangement enabled cu r r en t i n both c i r c u i t s t o be read on one ammeter. Both hea ters operated a t a l l t imes whether the ammeter was i n o r out o f the c i r c u i t . PROCEDURE A f t e r the bath hea ter and s t i r r e r had been s t a r t e d , the t e s t c e l l was f i l l e d to the over f low tube . The l i q u i d be ing 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 gases. The heater was then lowered , 1 1 . f o r c i n g the excess l i q u i d out the over f low tube . The our ren t was swi tched on and adjus ted i n the cen t re and guard r i n g u n t i l the d e s i r e d temperature was ob ta ined a t bo th h e a t i n g s u r f a c e s . The water f l o w i n g through the c a l o r i m e t e r was ad -j u s t e d u n t i l the bottom surface temperatures were un i fo rm. About 4 to 6 hours were r e q u i r e d to a t t a i n e q u i l i -b r ium. A f t e r one hour a t e q u i l i b r i u m read ings were r eco rded . The thermopi les were read every 10 minutes f o r one hour and the water r a t e was checked every lj> m i n u t e s . t o make sure i t was cons t an t . The r a t e was measured by c o l l e c t i n g the water i n a graduated c y l i n d e r f o r a p e r i o d o f f i v e minu tes . RESULTS Theory o f Measurement The thermal c o n d u c t i v i t y was determined from the steady s t a t e equa t ion K » SkSL. £ - the heat f l o w . T h i s was found by measuring the r a t e o f f l o w o f water through the 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 wa te r . The average d i f f e r e n c e over one hour was taken as the temperature d i f f e r e n c e . /AX - the d i s t anoe between the two sur faces or two o f the thermocouples s t r e t c h e d through the l i q u i d . These d i s t ances were measured by a depth 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 q u e s t i o n . A - the area o f t e s t c a l o r i m e t e r 12. The Thermal C o n d u c t i v i t y of Water To t e s t the apparatus i t was dec ided t o measure the thermal c o n d u c t i v i t y o f d i s t i l l e d wate r . The va lue f o r water has been obta ined by a number of i n v e s t i g a t o r s and i n recen t years i t s va lue 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 ives some of the l a t e r va lues o b t a i n e d . Observer Year Kc a t 30°C ( G a l °C-1 Cm- 1 ) J a k o b 1 0 1920 .00144 Bridgeman 1923 .00144 D a v i s 1 1 1924 .00146 Kaye and H i g g i n s 1928 .00151 Smith 1930 .00144 Bates 1936 .00145 The f o l l o w i n g da ta and r e s u l t s were ob ta ined f o r wate r . The area o f the c a l o r i m e t e r was, 37*66 s q . cms. The d i s t ance between the thermocouples was # 1 to #11 = 1.201 cms. # 1 to #18 - .546 cms. #18 to #11 » .655 cms. The t rue thermal 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 ance between thermocouples #1 to #11. J u s t i f i c a t i o n 1 0 A n n . P h y s i k . 63, 537 (1920) 1 1 E h i l . Mag. 47 , 922 (1924) 13. for using the distance between thermocouples is shown in the i graph of the temperature gradient through the liquid (Fig. 6). A typical data sheet for water follows: Date: June 26, 1946. Start: 12:00 A.M. Run #7 Time 2.00 3.00 4.00 5.00 5.30 7.30 TC# 1 1556 1577 1587 1595 1598 1599 microdot* 2 1752 1775 1784 1792 1806 1809 M 3 1748 1772 1783 1790 1803 1812 •» 4 730 730 736 736 734 731 3 730 730 736 736 734 731 %• 18 1294 1305 1312 1316 1318 1320 n 7 753 730 738 739 739 733 H 8 1748 1771 1782 1790 1800 1810 11 9 742 746 742 750 744 743 U 10 1749 1771 1781 1790 1800 1800 1 1 11 970 974 1762 977 979 978 978 M 12 1740 1773 1781 1790 1799 r 15 736 738 732 739 736 752 •1 Current C .220 .220 .220 .219 .219 .219 (amps) Gr .610 .610 .610 .610 .610 .610 Volts 431 43JL 430 43LO 43.0 4^ 0 Thermopile readings and water rate. Time 1+* WR (Minutes) #16 #13 cc/10 m. 0 2846 2950 10 2844 2948 612 20 2837 2939 30 2838 2948 612 40 2851 2950 50 2851 2948 60 2828 2953 612 70 2855 2964 80 2844 2961 90 2841 2960 612 100 2840 2962 110 2841 2961 120 2841 2960 612 Calculation of Thermal Conductivity A AT A - 37.66 sq. cm. 14. A X - 1.201 s q . cm. (Dis tance between #1 and #11) ^ T - 1.598 - .978 - 620 m i c r o v o l t s - 15 .50 °C. Q - Average #13 2.953.3 '» #16 2.842.9 " D i f f e r e n c e « 111.4 m i c r o v o l t s Water r a t e = 6.13 c o / m i n . » 111*1 i i l 2 l m .711 c a l s / s e c . 160 (600) K = .711 (1.201) . > 0 0 1 4 6 c a l s 37.66 (15.50) om. °0 s ec . a t 32.8 °C For v a r i o u s temperatures , the r e s u l t s g i v e n 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 N o . Top Surface Temp. °C AT cms. Heat Flow C a l s / s e c AT °C A cm 2 E e a l / c m - ° C -sec Temp o f r e a d i n g °C 5 • 315 1201 .456 9.74 37.66 .00143 212 7 45L6 1201 -711 15^0 3*66 .00146 328 8 5512 1201 1138 2£L4 37.66 .00145 39-3 9 432 IL201 •579 12^ 5 37.66 .00146 29.6 A comparison of Ba t e s ' va lues with, these a t the same temperature i s g i v e n i n the next t a b l e . Temp. KQ Bates KQ 2 7 . 0 0 1 4 3 .00144 30 .00146 .00145 33 .00146 -00146 39 .00145 -00148 C o n s i d e r i n g how o l o s e the temperatures c o u l d be read and v a r i e t y o f r e s u l t s ob ta ined by o ther i n v e s t i g a t o r s , i t was decided tha t the above r e s u l t s showed tha t the ap-15. paratus was satisfactory for measuring the thermal conduc-tivities 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.^2 The purest fraction of each isomer from this was about 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.1^ After re-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 recrystal-lized 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 con-ductivity 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. i<:Angley Potkins and Rush - Bachelor Thesis 1942. ^J .A.C.S . 60, 2125 (1938) Date: July 12, 1946 Start: 11:30 A.M. 16. Run #22 Time 2,00 4 .00 5 .00 5 .30 6.00 TC# 1 1642 1691 1700 1701 1702 Wn'ovol*! 2 1888 1946 1953 1954 1956 3 1916 1975 1982 1982 1984 4 710 712 714 715 712 5 . 710 712 714 714 712 18 1344 1366 1375 1375 1376 7 711 712 715 715 712 8 1915 1975 1981 1982 1984 9 734 735 738 738 736 10 1915 1975 1981 1982 1984 11 1011 1022 1024 1024 1024 12 1881 1932 1943 1943 1945 15 726 726 750 730 726 Current C .115 •115 .115 .115 .115 (amps) G -502 .502 .502 .502 .502 Volts 42 42 42 42 42 Time WR #15 (Minutes) #16 , co/5 m. 0 2811 2857 10 2819 2859 261 20 2816 2858 30 2814 2857 40 2811 2858 261 50 2814 2860 60 2818 2857 Calculations: A « 37*66 sq. cm. AX » 1.222 cm. AT » 1*701 - 1.024 . l 6 # 7 4 o C 40 q « 2.8^ 8 - - 2 . 8 1 ? 12611 . .234 cals/sec 160 (300) K - »2?4 (1.222) „- # 0 0 0 4 ^ oal 37.66 (16.74) cm - sec °C at 35.8 °C The following results were obtained for various temperatures. 17. Run Top A S Heat i£T A K Temp o f No . Surface cms. Flow °C cm2 c a l / c m - ° G r ead ing Temp. S - 3 6 © °G °G c a l s / s e c 15 37.2 1222 .1366 10.71 37*66 .000413 310 16 255 1222 .0464 £33 37-66 .000454 217 18 5o\8 1222 •309 2195 3^66 .000457 388 19 253 1222 .0558 3-75 37.66 .000483 216 21 247 1222 .0487 £25 31166 .000484 214 22 495 1222 .234 16.74 3746 .000455 358 25 82. o 1222 .647 39,40 37.66 •000534 33L6 C i s Decahydranapthalene The f o l l o w i n g are the r e s u l t s f o r the^ thermal con-d u c t i v i t y o f c i s decahydranapthalene. A data sheet and c a l c u l a t i o n are f o l l o w e d by a t a b l e o f v a l u e s . F igu re 8 shows the v a r i a n c e o f thermal c o n d u c t i v i t y w i t h temperature . Da te : J u l y 16, 1946 S t a r t : 11:00 P . M . J u l y 15 Run #31 Time 9.00 9.30 10.00 10.30 TG# 1 880 880 882 888 2 970 972 973 973 I f 3 981 981 983 985 H 4 692 692 695 695 H 5 708 710 710 710 • 1 18- 832 833 833 841 Ik 7 710 710 710 710 If 8 981 982 983 985 *M 9 714 715 715 716 It 10 983 984 986 988 la 11 761 762 770 769 to 12 970 971 971 974 • 1 15 714 714 715 715 U Current C -056 .056 .056 .056 G .225 -225 .225 .225 V o l t s 13 13 13 13 1 8 . Time WR Minutes O u t l e t I n l e t c c / 5 m i n . 0 2832 2816 5 2828 2819 10 2828 2816 15 2830 2819 202 20 2832 2815 25 2832 2819 50 2834 2818 204 35 2834 2818 40 2836 2818 45 2832 2817 203 50 2832 2817 55 2831 2818 60 2831 2818 A v e . 283L7 2817.5 203 C a l c u l a t i o n s : A " 37*66 sq.. cms. A X = 1.222 cms. A T - 885 - 767 m 2.95°C 40 q, m 142 (20?) • , w 0 6 o i c a l s / s e c . 160 (300) K m .0601 (1 .222) m ,000656 c a l s 37*66 (2 .95) om - s e c ' C a t 21.2°C The f o l l o w i n g r e s u l t s were ob ta ined a t v a r i o u s temperatures . Run Top A X Heat A T A K Temp o f No. Surface cms. Flow °C cm.2 c a l s r e a d i n g O Q Temp. °G % cm-sec °C _ , C a l s / s e o 26 52J. .670 .371 780 37.66 .000724 319 28 519 .670 .301 ao3 37.66 .000660 302 29 510 1222 .359 15.06 37.66 .000775 354 30 7&\6 1222 ,671 .060 36.95 37.66 .OOO656 528 31 253 1222 295 37-66 .0OO656 212 32 35B 1222 .407 2110 3^ 66 .000624 374 33 411 .670 .229 5-71 37.66 .000712 31-9 19 . E x p l a n a t i o n of R e s u l t s The reasons f o r the e r r a t i c r e s u l t s ob ta ined f o r the thermal c o n d u c t i v i t y of the decahydranapthalenes may be as f o l l o w s : 1. Leakage o f the c o n t a i n e r . Great d i f f i c u l t y was encountered i n making the con t a ine r impervious to d e o a l i n . To prevent leakage the whole o f the i n s i d e o f the oon t a ine r was covered w i t h "Cenoo" l a b e l v a r n i s h which was s a t i s f a c t o r y f o r two or th ree runs but e x t r a cos t s were then r e q u i r e d . The l a b e l v a r n i s h decreased the c o n d u c t i v i t y o f the bottom meta l sur faces which r e s u l t e d i n a l onge r t ime be ing neces-sa ry 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 nc r ea sed the l i k e l i h o o d o f heat l o s s down through the t r a n s i t s t o the bottom s u r f a c e . 2 . The i n l e t the rmopi le #16 s t a r t e d to read too h i g h . Th i s was probably because heat was conducted a long the t he rmop i l e from the ou t s ide or because the the rmopi le was touch ing the meta l i n the t e e . The thermopi le was removed and an attempt was made to f i x i t but a f t e r a few runs i t aga in read h i g h . Thus to o b t a i n the i n l e t temperature i t was necessary to remove the heater and r u n the water through as f a s t as p o s s i b l e and thus be unable to p i c k up any hea t . #13 was then read and t h i s gave the i n l e t temperature o f the wa te r . T h i s was not comple te ly s a t i s f a c t o r y as i t d i d not g i v e the i n l e t temperature at the same t ime as the o u t l e t temperature . The o b t a i n i n g o f a h ighe r thermal c o n d u c t i v i t y f o r the c i s isomer as oompared w i t h the t r ans isomer i s t o be ex-2 0 . pec ted . Th i s c i s form has a h ighe r d e n s i t y , i . e . the mole-c u l e s are c l o s e r t oge the r , and thus i t should be ab le to t r a n s f e r heat more r e a d i l y . SUGGESTIONS FOR FUTURE OPERATION 07 APPARATUS  Connect ions 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 keeping 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 oge the r . Over the p e r i o d o f t ime necessary f o r e q u i l i b r i u m , d e c a l i n would seep through 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 ther patent o rgan ic p r o t e c t i v e coa t i ngs are qu i t e s o l u b l e i n c i s decahydranaphthalene. Le Pages glue i s s o l u b l e i n d e c a l i n un less baked a t 100°C f o r two hours o r more. "Genco" l a b e l v a r n i s h i s r e s i s t a n t to d e c a l i n but sof tens at about 80°G. I t i s too t h i n to be o f any use i n j o i n i n g two p ieces o f m e t a l , o r meta l and t r a n s i t s , but can be used to coat a more p rev ious but r i g i d cement. The two best cements found f o r the job 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 . The Saur iesen i s o n l y u s e f u l i n t h i n l a y e r s . The Wfeldwood i s u s e f u l i n t h i n coa t ings or t h i c k l a y e r s and i s the re fo re the most convenient to use f o r j o i n i n g the p a r t s o f the c e l l . Before f u r t h e r measurements are a t tempted, i t i s suggested tha t the c a l o r i m e t e r be separated from the t r a n s i t s and the g l a s s thermocouple tubes removed. A f t e r c a r e f u l c l e a n i n g , the pa r t s should be reassembled u s i n g Wfeldwood f o r a l l connec t ions . The g l a s s tubes should be r e i n s e r t e d and f i x e d w i t h Wfcldwood. A t l e a s t f o u r days should be a l l owed f o r the cement to harden un less the l a y e r i s ve ry t h i n , when two days w i l l be s u f f i c i e n t . Thermopiles Some d i f f i c u l t y was encountered i n g e t t i n g t r u e readings o f the water i n l e t temperature to the c a l o r i m e t e r . I t was a t f i r s t f e l t tha t the i n s u l a t i o n had f a i l e d caus ing meta l to meta l contac t of the brass and the t h e r m o p i l e r how-e v e r , examinat ion r e v e a l e d no f l aws i n the i n s u l a t i o n . Sinoe the the rmopi le l eads were o n l y immersed i n the water 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 long the w i r e s to the j u n c t i o n caus ing too h i g h a temperature to be r ead . I t i s suggested tha t the p o s i t i o n o f the thermopi le hot j u n c t i o n s be changed so tha t the incoming and ou tgo ing water f lows over at l e a s t s i x inches o f the l e a d w i r e s i m -media te ly p reced ing the j u n c t i o n s . 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 j u n c t i o n i n the f ree stream, a minimum r e s i s t a n c e would be o f f e red to the f l ow o f the l i q u i d past the w i r e s . The j u n c t i o n should be i n s u l a t e d so there i s no p o s s i b l e chance o f con tac t between the j u n c t i o n and the brass c o n n e c t i o n . Conta ine r . Cons iderab le d i f f i c u l t y was exper ienced i n f i x i n g the c e l l t o the water p ipe connect ions owing to the i n a c c e s -22. s a b i l i t y of the connec t ions . I t i s suggested tha t a l a r g e * window be cut i n the ou t s ide meta l con t a ine r to improve v i s i -b i l i t y when work ing 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 apparatus s h o u l d , w i t h minor adjustments , enable the thermal 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 to be measured. There i s need of cons ide rab l e work i n t h i s f i e l d as very l i t t l e has been done. The thermal c o n d u c t i v i t y o f the c i s and t r ans isomers o f v a r i o u s o ther o rganic compounds c o u l d a l s o be i n v e s t i g a t e d to see whether o r not the c i s isomer has a h ighe r c o n d u c t i v i t y i n every case . CONCLUSION An apparatus f o r measuring the thermal 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 to 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 wate r , the thermal con-d u c t i v i t y of which 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 thermal c o n d u c t i v i t i e s o f the c i s and t r ans isomers o f decahydranaphthalene were a l s o measured. Al though somewhat e r r a t i c r e s u l t s were ob ta ined f o r these compounds i t was found tha t i n a l l cases the c i s isomer had a h igher thermal c o n d u c t i v i t y than the t r ans i somer . Wi th t h i s apparatus 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 long the, l i n e s suggested. 

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