Oct., 1 9 1 j
T H E J O I ; R L V A L O F I.l'Dt7STRI.4L . 1 S D E.tTGI~VEEIZI,VG C H E M I S T R Y
871
LABORATORY AND PLANT A NEW APPARATUS FOR FAT EXTRACTION By I SELECTEX
Received J u n e 24, 1915
F r o m t h e varied forms of a p p a r a t u s for t h e extraction of f a t t h a t are upon t h e market. it would seem that t h e r e is n o t one in use t h a t meets t h e approval of all laboratories. I n laboratories for control n-ork, t h e chief requisites of a n a p p a r a t u s of this n a t u r e are uniformity of results, better extraction and ease in manipulation. If t h e n u m b e r of units in use is necessarily large, t h e cost a n d durability are also i m p o r t a n t . T o meet these requirements, an app a r a t u s \\-as devised for use in t h e Feed Laboratory of t h e Louisiana Experiment Station. Some portions of this are similar t o p a r t s of a n a p p a r a t u s used in t h e laboratory of Prof. G. W. Cavanaugh in Cornell LTniversity. though t h e principle of extraction is somewhat different. I n s t c n d of soaking t h e sample in t h c liquid e t h e r , or whatever t h e solT-eiit m a y be, as is t h e case with most of t h e a p p a r a t u s nolv in use, i t is s a t u r a t e d with t h e vapors a n d is periodically flooded with t h e redistilled liquid. T h e a p p a r a t u s as shon-n in Fig. I . consists in t h e main of t!ircG parts: (I) Condensing section, ( 2 ) tiooding section, (3) reser\-o:r. T h e condensing section E is made of a t u b e I S in. long a n d I I , ' ~ in. in dianieter. 'This is flanged slightly a t t h e t o p and clran-n o u t a t t h e b o t t o m into a ground glass e n d t o fit tlie t o p of section B . I n t o this l a t t e r is first p u t a regular Soxhlet extraction t u b e , D , 6 in. long, having merely a siphon t u b e on t h e side. Above this is t h e condenser proper, F , which consists of a glass t u b c 1 2 jn. long ant1 in. in diameter. This latter is also flanged a t t h e t o p , a n d is suspended from t h e flanKed p a r t of t h e outer t u b e . I n t o t h e t o p of t h e conclenser is fitt.ed a n ordinary tn-o-holed rubber s t o p p e r , G . Through t h i s are p u t t h e t u b e s I27 a n d I . T h e ad;-antage of this t y p e of .condenser instead of one v i t h t h e sealed-in t u b e s is readily apparent. F i r s t , in t h e cost of making. since t h e former can easily be made in t h e laboratory b y sealing one end of a 1'/4 in. t u b e a n d drawing i t o u t t o a point. n-hi!e t h e upper end is flanged so t h a t i t \\-ill hang suspended in t h e outer tube. T h e r e is t h e additional ad\-antage of t h e rubber stopper in being able t o clean tile condt.nser when necessary without a n y difficulty 17-hatever. T h e n , too, t h e t u b e s t h a t extend into t h e condenser can be bent in t h e laboratory, so t h a t broken parts can be replaced cheaply a n d readilj-. T h e flooding section B is made of a straight glass t u b e j in. l o n g a n d I in. in diameter. This is ground
a t t h e t o p t o fit t h e lower p a r t of section E . T h e ordin a r y Schleicher a n d Schull capsule which contains t h e weighed sample of t h e feedstuff is placed in this part. T h e reservoir consists of a f j cc. Erlermeyer flask ground t o fit t h e end of section B . T h e solvent is placed in t h e flask a t t h e b o t t o m a n d t h e vapors pass through t h e sample, thereby saturnti% it. Condensation takes place a t t h e t o p , into t h e Soxhl e t t u b e below, which on siphoning over floods t h e sample, t h u s leaching out t h e extract. T h e rate of flooding can readily, be regulated b y t h e a m o u n t of h e a t placed a t t h e b o t t o m . One of t h e i m p o r t a n t features of this a p p a r a t u s is t h e recovery of t h e ether t h a t has been used in t h e e s traction. This is a considerable factor in a control laboratory n-here large a m o u n t s are used. I n a Soshlet arrangement, n-here t h e condensation is good, there will be enough left in t h e t u b e t o siphon over several times a n d one must wait until t h e solvent h a s evaporated sufficiently hefore t h e sample can be re.. moved; t h e r e are also stopcock arrangements ormercury joints b u t these are either \-cry delicate a n d liable t o breakage or t h e y Ivork imperfectJy. I n t h e n e v a p p a r a t u s \Then t h e extraction has gone on for t h e required .length of time, t h e flooding section is detached a n d R giass capsule is substituted for t h e paper one. On flooding. this fills a n d t h e flask containing t h e extract can t h e n be removcd without a n v d i E culty or loss of time. As t o arrangement in tlie laboratory. t h i s a p p a r a t u s can be set u p either single or in sets of three or more, on either s t e a m baths or electric hot plates For comparison of extractions with several kinds of a p p a r a t u s . three methods n w c chosen: ( I ) T h e so-called straight extraction method, n.hich has beer, in use in this laboratory for t h e , past Eve years; ( 2 ) the Soxhlet, which is most commonly used; and ( 3 ) this new apparatus. T h e straight estra.ction u n i t consists of a long t u b e condenser, similar t o a n y Liebig condenser, arranged with R cork stopper zil)ove a t u b e FATE X T R A C T I O S S STR.IIGHT C031MERCIAL
DS
EXTRACTIOS
TIIREI:~ I E T l l U l ~ ? SOXIILET
AUTHOR'S APPAR.?TI:S
FCED
Cottonseed meal Rice polish \Theat b r a n Corn chops >lolasses feed Chick f e e d M e a t crisps Beet scraps Digester tankage hlised b r a n
a b o u t 6 in. long into which t h e capsule containing t h e sample is placed. T h e extraction is carried on b y having t h e condensed ether drop directly upon t h e sample which is covered with cotton within t h e capsule a n d thence draining into t h e f a t h o r t l e which is placed below. I n this method there is neither flooding nor' soaking. T h e Soxhlet was arranged with a reflux condenser. Here, of course, r;he principle is saturation.
T H E J O U R N A L OF I N D C S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
87 2
T e n samples of commercial feeds were used a n d t h e results obtained for each of these feeds, using t h e official method for t h e determination, appear above. It can readily be seen from t h e above results t h a t t h e new a p p a r a t u s gave better extraction i n t h e greatest n u m b e r of cases, a n d averages higher in 8 o u t of t h e T O cases here n o t e d . I t was found, too, t h a t there is a greater uniformity in t h e results obtained, it being necessary in several instances t o make as m a n y as six d e t e r m i n a t i o n s with t h e straight extraction a p p a r a t u s .and four with t h e Soxhlet before checks within 0.2 per c e n t could be obtained. T o summarize, t h e a p p a r a t u s gives better extraction t h a n does either t h e straight extraction or t h e Soxhlet methods. I t is easy t o manipulate, presenting a smooth outer surface, reducing t h e danger of breakage t o a minimum. T h e recovery of t h e solvent is easy a n d rapid a n d entails no loss of time. T h e cost of t h e a p p a r a t u s is also comparatively small. Acknowledgment should be made t o M r . A. P. K e r r , Assistant Director of this station, for his suggestions. LOUISIANA AGRICULTURAL EXPERIMENT STATION BATONROUGE,LOUISIANA
A SIMPLE, DURABLE, ELECTRICALLY OPERATED GAS-VALVE By ZENO OSTENBERG Received June, 21, 1915
T h e valve herewith illustrated was designed a n d built t o regulate t h e flame of a double-burner gas-stove, which heated a large water b a t h 24 in. in diameter. Since t w o of t h e m have been in operation for over a year a n d a half, with entire success, i t was t h o u g h t t h a t a description a n d illustration of t h e mechanism would be useful t o others. T h e mechanism consists essentially of t h e “ironclad” electromagnet A , which lifts t h e iron disc B t o which is a t t a c h e d t h e brass valve a n d s t e m C. T h e brass valve C makes a gas-tight fit with t h e main brass body D at t h e inlet E when no current is passing T
c
E
t h r o u g h t h e magnet winding, b u t when CUrrent is sent through the magnet the disc and .C a r e raised a n d t h u s gas is allowed t o pass from E
Vol. 7, ?;o. I O
t o K , which leads t o t h e burner. F is t h e outlet t o a pilot light. T h e disc B is prevented from sticking t o t h e magnet A b y t h e plug S , which m a y be screwed down t o limit t h e travel of t h e valve s t e m C . G is insulation which must be able t o withstand a rise of t e m p e r a t u r e u p t o a b o u t IOO’, as t h e magnet sometimes becomes quite hot. T h e disc H is of brass a n d is soldered gas-tight t o t h e magnet A t o prevent moisture a n d gas from attacking t h e wiring a n d also t o keep t h e wiring in place. T h e gas inlet t u b e ( n o t shown) enters opposite t o t h e pilot opening F. When opera t e d from a I I O volt line, t h e winding consists of No. 2 6 d. c. c. copper wire with a 16 c. P . carbon l a m p i n series. This allows slightly less t h a n 0.5 ampere t o pass through t h e winding of t h e electromagnet. F o r use with a storage b a t t e r y No. 30 wire is used. T h e electrical circuit is opened a n d closed b y a 7 5 o h m s t a n d a r d P o n y relay, which is operated b y a d r y b a t t e r y a n d thermoregulator. T h e d r y batteries, which were originally p u t into t h e thermo-regulator circuits over a year a n d half ago, are still able t o operate t h e relays as only a b o u t 0 . 0 2 ampere is used, a n d t h i s a m o u n t of current is so small t h a t no trouble whatever has been experienced from oxidation of t h e mercury at t h e contacts in t h e thermo-regulators. Obviously t h e valve m a y be used on a n y size of burner, f r o m t h e smallest micro-bunsen t o one which h a s a gas inlet equal i n size t o t h e inlet a n d outlet of t h e valve. I n t h e valves in use these holes a r e 0 . 2 5 inch in diameter. 2233 WEESTER ST., S A N FRANCISCO
PORTABLE TITRATING TABLE1 By R.
E. Ozras
Received June 16, 1915
Fig. I shows a convenient portable titrating t a b l e which has recently been installed in t h e United S t a t e s Appraiser’s Laboratory at New York. T h e burettes are operated b y compressed air supplied by a Goodyear air bottle which rests on a shelf a t t a c h e d t o t h e table. T h e air is conducted through ‘/8 in. a n d l / k in. brass pipe t o t h e main pipe ( I in. diameter), on t o p of table, on which are seen t h e air pressure gauge a n d Lunkenheimer t h e individual t a p s fitted with ‘/a brass spring key cocks. T h e t o p of t h e table is 3 ft. X 6 f t . a n d is perforated with 8 circular oaenings, j in. in diameter, i n which t h e bottles are placed, resting on a base board securely fastened j in. below t h e t o p . T h e s t a n d a r d solution bottles are of d a r k glass, 2 5 0 0 cc. capacity, a n d as shown are eight in number. Without necessarily increasing t h e size of t h e table, a second row of eight bottles could be placed in a simil a r position a n d t h u s give i t a capacity of sixteen s t a n d a r d solutions. N o moisture or carbonic absorption a p p a r a t u s is shown o n t h e t r a i n , a s t h e solutions employed did n o t require their use, b u t when necessary those accessories 1 Published Rith the consent of the Secretary of the Treasury and United States Appraiser. Port of N e w York.
