Apparatus for vacuum distillation

VACUUM Classified A b s t r a c t s

III

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Vacuum

Processing Techniques - -

III

Abstract No. and References

Contd.

in a tlask, p o s i t i o n e d lower down, w h i c h serves a t t h e s a m e t i m e as t h e r e c e p t a c l e for t h e d i s t i l l a n d p r i o r t o o p e r a t i o n s . Before t r e a t m e n t is s t a r t e d t h e m a t e r i a l is p a s s e d b y m e a n s of a n ' air lift ' p u m p t o t h e r e s e r v o i r a t t h e top. F r o m t h e r e it is fed t h r o u g h a drop c o u n t e r on t o t h e first stage, w h i c h l i ke t h e o t h e r t w o c ons i s t s of a piece of t u b i n g p o s i t i o n e d v e r t i c a l l y a n d filled w i t h a s o l v e n t h e a t e d b y s e p a r a t e m e a n s in e a c h case. The d i s t i l l a n d flows over t h e o u t e r (specially roughene d) surface of t h i s t ube , t h e d i s t i l l a t e be i ng collected i n a g u t t e r (one to each stage) a n d t h e r e s i d u e b e i n g coll e c t e d on a n i n c l i n e d flange a t t h e b o t t o m of t h e t ube . F r o m here t h e r e s i d u e passes i n t o feeding t u b e s w h i c h c o n v e y i t to t h e re s i due fl a s k m e n t i o n e d before. The d i s t i l l a t e of each s t a g e collects in a s m a l l flask, from w h e r e i t is c o n v e y e d t o t h e n e x t stage. T h e o p e r a t i o n a l laressure is 10 -~ m m . H g p r o d u c e d b y a 3 s t a g e oil diffusion p u m p uni t . A f t e r c o m p l e t i o n of a r u n t h e re s i due collected in t h e flask is r e t u r n e d to t h e r e s e r v o i r a n d a n o t h e r r u n is s t a r t e d . B y w a y of e x a m p l e t h e t r e a t m e n t of c o m m e r c i a l l y a v a i l a b l e oleic acid is described. The i n i t i a l c h a r g e w a s 80 g. The t e m p e r a t u r e of t h e s t a g e s was 96°C. I n t h e first r u n 25°~, of t h e d i s t i l l a n d w a s r e m o v e d in s e v e n di s t i l l a t e s . T h e n a second r u n w a s carried o u t after r a i s i n g t h e s t a g e t e m p e r a t u r e to 102°C a n d a f r a c t i o n of 2 3 g r a m s w a s collected e v e r y 1½ hours. At t h e en d of t h e process, 0.6 g. of t h e d i s t i l l a n d w a s found in t h e cold t r a p , 2.3 g. in t h e still a n d 2.0 g. in t h e ' air lift ' line a n d t h e reservoir.

O

Sommaire : Un e colonne de d i s t i l l a t i o n moldculaire /t 3 dtages, du t y p e s /~ 6 c o u l e m e n t v e r t i c a l de couches, a ~t4 d~veloppSe p o u r des c h a r g e s i n i t i a l e s de 80 g de m a t i ~ r e ; son efficacitd est di t e d ' e t r e 2.5 lois p l u s g r a n d e que c e t t e d ' u n e colonne 5, u n 6tage. Apparatus for V a c u u m Distillation United States. I n a m o l e c u l a r still t h e v a p o u r s of t h e diffusion p u m p l i q u i d are i n t r o d u c e d a t t h e surface of t h e e v a p o r a t i n g film a n d b y e n t r a i n m e n t of t h e e v a p o r a t e d molecules, a i d i n c a r r y i n g t h e m t o t h e condenser. ( Chemical Abstracts) Sommaire : Une colonne de d i s t i l l a t i o n m o l d c u l a i r e d ' u n modSle special e s t d~crite.

39 --

O

MISCELLANEOUS

PROCESSES

Article by D. A. Sutton Chem. & Industr. 26.12.1953 1383-5

42/III W. B. Whitney & Phillips Petroleum Co. U.S. Pat. 2,647,862

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The Influence of Barometric Pressure on W a t c h and Chronometer Rates See A b s t r a c t No. : 1 5 / I

43/III

Design and Operating Technique of a V a c u u m D r y i n g Oven See A b s t r a c t No. : 2 3 / I I I

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Pre-Cooling Fruit and Vegetables United States. D e t a i l s are g i v e n of t w o v a c u u m - c o o l i n g p l a n t s e m p l o y e d for t h e pre-cooling of fresh p r o d u c e pr ior to s h i p m e n t or cold storage. I n a v a c u u m of 29.8 i n c h H g w a t e r boils a t 3 2 ° F a n d t h e e v a p o r a t i o n of 1 lb. of w a t e r a b s o r b s 1,000 B.t.u. of heat. The e x t r a c t i o n of 1 lb. of w a t e r , from 100 lb. of l e t t u c e a t t h a t p r e s s u r e r e d u c e s t h e l e t t u c e t e m p e r a t u r e b y 10°F. I n t h e case of t h e first p l a n t d e s c r i b e d t h e t e m p e r a t u r e i n t h e cooler is r e d u c e d t o 3 2 ° F in 15 m i n u t e s a n d h e l d t h e r e for 2 m i n u t e s , The final t e m p e r a t u r e of t h e p r o d u c e w a s 34°~". The v a c u u m r e q u i r e d is p r o d u c e d b y s t e a m ejectors. The second p l a n t is m a d e up from t h r e e cooling c h a m b e r s w h i c h are o p e r a t e d in series in such a m a n n e r t h a t e a c h c h a m b e r is p a r t i a l l y e v a c u a t e d before t h e a c t u a l cooling o p e r a t i o n s t a r t s . H e r e t h e t e m p e r a t u r e of t h e p r o d u c e is r e d u c e d from 73° F t o 32° F in 30 m i n u t e s b u t in o r d e r to cool t h e p r o d u c e r i g h t t h r o u g h , t h e p r e s s u r e is allo w e d t o i nc re a s e for a s h o r t p e r i o d a t a s u i t a b l e m o m e n t d u r i n g t h e process. The o v e r a l l p r o d u c t i o n t i m e for one b a t c h w a s 70 miflutes. The first p l a n t h a d a c a p a c i t y of 50 c r a t e s (-- 50 × 36 h e a d s of l e t t u c e , for instance) pe r charge. The second p l a n t h a d a c a p a c i t y of 72 c r a t e s p e r o p e r a t i o n a n d w a s r u n n i n g a t full load for e i g h t m o n t h s of t h e year. The process is successful i n t h e case of l e a f y v e g e t a b l e s i n c l u d i n g I t a l i a n s p r o u t i n g brocoli, celery, spinach, l e t t u c e a n d cole s l a w s a l a d b u t s t r a w b e r r i e s , b e a n s a n d peas in pod are found to burst, a n d t o m a t o e s , b a n a n a s a n d cauliflowers are also f o u n d unsatisfactory. The q u a l i t y of some v a r i e t i e s of a p p l e s d e t e r i o r a t e s in t h e process. The loss in w e i g h t of p r e - p a c k e d v e g e t a b l e s t r e a t e d b y t h i s m e t h o d was i n v e s t i g a t e d a n d found t o r a n g e from 2.2 to 3.2°o. V a c u u m cooled p r o d u c e can be p a c k e d a n d t r a n s p o r t e d more effi c i e nt l y a n d c h e a p l y t h a n p r o d u c e r e f r i g e r a t e d w i t h ice. V a c u m n cooling l e n g t h e n s t h e shelf life of t h e m a t e r i a l a n d a v o i d s t h e r i s k of d a m a g e b y b a c t e r i a l a c t i v i t y a n d m o u l d g r o w t h c a u s e d b y t h e m e l t i n g ice. Sommaire : Des d~tails s e n t donn6s sur d e u x a p p a r e i l s de cong61ation sous vide, e m p l o y 6 s d a n s l ' i n d u s t r i e a l i m e n t a i r e en Am~rique, p o u r la c o n g ~ l a t i o n ~ g r a n d e dchelle de l dgume s e t p r o d u i t s a l i m e n t a i r e s varids.

45/III

The Recovery of Essence f r o m Florida Orange Juices United States. A s y s t e m for r e c o v e r i n g w a t e r - s o l u b l e essences of o r a n g e juice u n d e r v a c u m n a t t e m p e r a t u r e s of 110 -1 15°F is described. The o r a n g e juice w a s n o t n o t i c e a b l y d e t e r i o r a t e d b y p r o c e s s i n g a t t h o s e t e I n p e r a t u r e s . I t w a s n e c e s s a r y to e v a p o r a t e a t l e a s t 20°'0 of t h e juic e t o o b t a i n t h e b u l k of t h e essence. A r e l a t i o n e x i s t e d

j a n u a r y , 1954

Vacuum Vol. I V No. I

Article by Anon. World l~efrig. 4, July 1953 386-389

46/III

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