A pr ., I 9 I 6
T H E J O C R N A L OF I N D C S T R I A L A N D ENGINEERING C H E M I S T R Y
ble so t h a t one may a t a n y time know t h a t there is ample flow of water through t h e condensers. These tubes should not, therefore, dip into t h e trough. The trough (galvanized sheet iron) is about 3 . 5 cm. wide, about 13 cm. deep and. of wafer course, extends along t h e entire length of t h e “plant.” These condensers prevent completely loss of liquid by evaporation, and suppress, or hold sufficiently in check, frothing. But t h e boiling must be started gently and conducted gently; violent ebullition is not at all necessary and is t o be avoided. Frothing is due t o bubbles filled with steam-and doubtless t o some extent with hot air; condense t h e steam and t h e bubbles or froth collapse. The upper region of t h e beakers is kept cool t h e condensers; hence FIG. 11-REFLUX CONDENSERby there is no need of a cold FOR USE ON BEAKERS IN CRUDEFIBERDESERblast of air-it is t h e coldMINASION ”ress, not t h e blast, t h a t checks ( 1 1 4 Size) t h e frothing. A cold airblast could, however, be easily introduced through these condensers. Such a condenser is shown on a beaker in t h e foreground of Fig. I. Beakers of joo cc. capacity, 7 . j cm. inside diameter and 14 cm. high, Jena glass, are preferred; b u t beakers of 600 cc. capacity, 8 cm. diameter, I j . 5 cm. high, can be used interchangeably with t h e smaller ones. The beakers can be given a rotary shaking without lifting t h e m from t h e heating plate. After t h e boiling has been gotten under way and t h e beakers have been rotated a time or two, t h e apparatus may be left to itself. The heating plate (wrought iron) is about 4 mm. thick and has a top surface about 9 . j cm. wide. Along its entire length is turned a flange about 2. j cm. wide. The object of t h e flange is t o give rigidity and prevent sagging or buckling. LABORASORY OF THE NORSHCAROLINA DEPARTMENT OF AGRICULSURE, RALEIGH
A FURNACE FOR CRUDE FIBER INCINERATION By J. M. PICKEL Received May 28, 1915
If t h e chemist have a t his dispbsal t h e requisite electric current and $ 5 0 t o $100, he will be a p t t o invest in a n electric furnace. If he have b u t a dollar or two, he can, with t h a t capital and with materials ready t o hand in t h e laboratory, construct a wonderfully efficient incinerating furnace. Such a furnace, occupying on t h e table a space 2 0 X 2 0 cm. (8 X 8 in.), is shown in Fig. I in t h e previous article (page 3 6 6 ) , at t h e left uncovered, a t t h e right as it appears when performing. Twelve crude fiber incinerations are made in I j t o 2 0 min. on, or in, this furnace
367
by t h e heat of one small Bunsen burner; and t h e ash is as nearly perfect as t h e writer a n d designer of t h e furnace has ever seen. A piece of asbestos board 0 . 7 X 1 9 X 19 cm., in whose center is cut a circular opening Q cm. in diameter, is laid on an ordinary laboratory tripod. On this board is set a disc of wrought iron (cast iron would probably be better) about 2 . 5 mm. thick a n d 1 3 . 5 cm. in diameter (14. j cm. would be better since i t would furnish space for several more incinerations). The disc is supported on three legs, I cm. long, screwed into it. On t h e disc are set 1 2 crucibles. alundum RA 98, 3 . 8 cm. high and 3 . 7 cm. in outside diameter, in which t h e fiber has been filtered, washed, dried and weighed. On t h e asbestos board is placed a n asbestos cylinder 15. j cm. in diameter a n d 6 . 5 cm. deep. The cylinder is covered with a piece of asbestos board of t h e same dimensions as t h e one previously described, but having in its center a hole only 3 . j cm. in diameter. A small Bunsen burner, whose gas tip has been widened somewhat by inserting t h e point of a penknife blade, furnishes t h e heat. The burner should be set o n a block so as t o bring its t o p close t o t h e iron disc, thus causing t h e flame t o spread over t h e under surface of the disc. I n a few minutes (6 or 8) t h e disc and t h e crucibles will be brought t o a bright glow. The cylinder is easily and quickly made. Strips of suitable width (about 6. j cm.) are cut from asbestos board of suitable thickness (about 7 mm.) and their ends beveled by shaving with a sharp knife. These strips are saturated with water, and, while wet, are wound, two or three thicknesses, around a suitable core (an empty 2-kilo ether can dr a piece of sheetiron stovepipe), bound in place by two or three bands of wire and allowed t o dry out a t room temperature and finally on or near a steam radiator. The core is removed and t h e lapped ends of t h e strips riveted. LABORATORY OF SHE NORTHCAROLINA DEPARSMENT OF AGRICULTURE, RALEIGH
A GAS PRESSURE REGULATOR By J. R. POWELL Received November 15, 1915
Occasion arose in this laboratory t o make use of a gas-heated thermostat, but a great deal of inconvenience was experienced because of varying gas pressure. I n casting about for some simple pressure regulator, the apparatus described below a n d illustrated in Fig. I was finally hit upon as a practical solution of the trouble. I t will be noted t h a t t h e apparatus is constructed from material readily obtainable in almost any laboratory; also t h a t there is no great skill required for its assembly. Practically every chemist has t h e rudimentary knowledge of glass-blowing necessary t o make t h e one “ Y ” required. A and C are rigidly fastened, in t h e position shown, t o a board which acts as a mounting for t h e whole apparatus. B is suspended inside of A on t h e end of E by a rubber stopper. E is so arranged t h a t it may
T H E J O U R X A L OF IiVDliSTRIAL A N D ENGIYEERING C H E M I S T P Y
368
have a slight lever movement about t h e point where it passes through t h e rubber stopper D: as a fulcrum. The rubber stopper D is cut very short and, t o give t h e tube E still greater freedom of movement. the hole cut for it m a y have the edges grooved on both sides. The “ Y ” on the end of E should be constructed with a rather small branch (about z mm.) as t h e extension of E , while t h e branch looking down should have t h e full opening of E (6 mm.). When B is depressed t h e small branch of the . i Y ’ ’ should be raised just above t h e surface of t h e mercury t h a t fills t h e lower end of C, t h e larger branch of t h e “ Y ” remaining below t h e surface. K h e n B rises slightly, both
FIG.I
-a
A-Round, narrow-mouthed, 1 lb. bottle with the bottom cut off. B-4 02. oil sample-bottle with the bottom cut off. C-25 mrn. X 20 crn. test-tube. E-6 mm. glass tube bent and provided with “Y” a t the end.
openings of the “ Y ” will submerge in t h e mercury. With t h e assembly made as described, A is filled about full of mineral oil and t h e apparatus is ready for use. Gas flows into C through t h e tube connection shown, from there through E to B and out through t h e tube from A . As soon as t h e pressure builds up sufficiently on t h e delivery side the bell B floats up slightly, plunging t h e end of E below t h e mercury and shutting off t h e gas till consumption again slightly reduces t h e pressure under B . As the end of E rises from t h e mercury the slug of mercury t h a t has closed the small branch of t h e “Y” is forced up into E , b u t is permitted t o flow back through t h e lower branch of t h e ((Y.’. The gas pressure on t h e delivery side can be regulated b y t h e weight of B or t h e length of E . Once set up and adjusted, this siniple apparatus will automatically deliver gas a t a reduced but constant pressure, irrespective of variations of t h e initial pressure. ARXOURGLUEWORKS,CHICAGO
A NEW FORM OF ABSORPTION BOTTLE FOR USE WITH EITHER CALCIUM CHLORIDE OR SODA LIME IN THE ELEMENTAL ANALYSIS OF CARBON AND HYDROGEN IN ORGANIC SUBSTANCES1 By HARRYI,. FISHER Received February 29. 1916
The U-tube as a container of calcium chloride or soda lime for the absorption of water and of carbon dioxide, respectively. has been in use for many years. I n general it is efficient, but on account of its shape i t has many disadvantages in t h a t it is fragile and unwieldly, and presents difficulties of support during 1 Presented a t the Seattle Meeting of the American Chemical Society, September, 1915.
Vol. 8, No. 4
t h e combustion and weighing and of filling a n d emptying which do not make it very popular, especially with students. The addition of ground-in stoppers, a n d of a brace and support for hanging as suggested by &IcIntire,l were very acceptable improvements. The tendency, however, has been t o use a bottle form of apparatus because this is easier t o handle iri every way. This new style of absorption bottle has a n inner tube fused t o t h e bottom of t h e bottle and a single, hollow, ground-in stopper which makes a gas-tight joint in t h e neck of the bottle a n d the top of t h e inner tube. Two kinds of stoppers have been designed as shown in the accompanying diagrams. In Pig. I , opposite t h e hole in t h e hollow stopper there is a narrow longitudinal depression about z mm. deep and 3 mm. wide. This is t o allow communication with the outer chamber and t h e side tube a t t h e same time t h a t the inner chamber IS in communication with t h e other side tube by means of t h e hole in the stopper. When the stopper is turned, communication is then entirely shut off from both tubes a t the same time. Around the bottom of t h e inner tube there are four small holes. The two arms or side tubes are bent upwards slightly where joined t o the
!,o
--! ! !
‘F I
jR ! !
I
i
neck in order t h a t in t h e collection of moisture a n y droplets t h a t may remain in t h e a r m will not easily run out when t h e apparatus is being disconnected. One a r m is provided with a small ground-in stopper t o prevent loss of moisture when the bottle is not connected in the absorption train. Only a minimum amount of grease should be used on this stopper so as not t o introduce any chance of loss with consequent error in weighing. The upper edge of t h e neck is beveled and smooth t o allow thorough cleaning. The bottle has a total available capacity of 3 0 cc., 6 cc. for t h e inner chamber and 2 4 cc. for t h e outer chamber. By way of comparison an ordinary 11 cm. U-tube has a n available capacity of z z cc. A larger stopper cannot advantageously be made because of t h e difficulty of drawing it out and lining it up for t h e grinding. The bottle represented in Fig. I1 has a small curved tube in t h e stopper which connects t h e opening in one a r m with t h e large inner tube of the bottle. The gas passes tlirough t h e inner tube as in the other bottle 1
J . A m e v , Chsm. Sor,, 33 (1911). 450-1.
