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
Ten 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 apparatus gave better extraction in t h e greatest number of cases, a n d averages higher in 8 out of t h e T O cases here noted. 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 many as six determinations with t h e straight extraction apparatus .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 apparatus 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. The cost of t h e a p p a r a t u s is also comparatively small. Acknowledgment should be made t o Mr. A. P. Kerr, 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 two of them have been in operation for over a year a n d a half, with entire success, i t was thought 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 attached t h e brass valve a n d stem 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
through t h e magnet winding, b u t when CUrrent is sent through the magnet the disc and .C are 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 temperature u p t o about 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 (not 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 lamp in 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 battery No. 30 wire is used. T h e electrical circuit is opened and closed by a 7 5 o h m standard Pony relay, which is operated b y a d r y battery a n d thermoregulator. The dry 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 about 0 . 0 2 ampere is used, a n d this amount 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 may be used on a n y size of burner, f r o m t h e smallest micro-bunsen t o one which has a gas inlet equal in 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 are 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 table which has recently been installed in t h e United States Appraiser’s Laboratory at New York. The burettes are operated b y compressed air supplied by a Goodyear air bottle which rests on a shelf attached 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. The 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, in 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 standard solution bottles are of dark 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 similar position a n d t h u s give i t a capacity of sixteen standard solutions. N o moisture or carbonic absorption apparatus is shown on t h e train, as t h e solutions employed did not 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.
Oct., 1 9 1 j
T H E J O C R S d L OF I i T D C S T R I d L A N D E N G I N E E R I N G C H E M I S T R Y
c a n be attached readily t o a n y individual connection o r placed a t or near t h e outlet from t h e air supply. T o operate, air is admitted t o t h e main pipe t o about I j lbs. pressure when t h e valve on t h e air bottle is
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orifice in order t o release air pressure gradually, for if released suddenly there will be upward flow of solution through t h e relief valve. T h e amount of air consumed is very small and as bottles are recharged at a cost of 31.00,t h e cost of air per a n n u m in operating a table with eight solutions should not be over j o cents. White tilings 6 in. square are placed along t h e front of t h e bottles a n d under t h e spits of t h e burettes, t h e distance between tiling a n d spit of burette being about 7 in. U. S . CCSTOXSSZRYICE, TREASURY DEPARTMENT 641 W A S H ~ X C T O N S T . , h7EW Y O R K
A SIMPLE GAS BURNER FOR SMALL LABORATORY FURNACES BY D.
L. RANDALL
Received June 21, 1915
FIG.I
closed, followed b y t h e closing of air valve on t h e vertical pipe leading from t h e supply. T o fill a n y burette, its corresponding air cock is opened cautiously until solution is moving into burette, when i t is closed, After t h e solution has passed
T h e burner described below was devised t o use natural gas instead of gasoline in heating a small assay furnace of t h e combined muffle a n d crucible type. Its merit lies in its simplicity a n d cheapness, as i t can easily be made b y any pipe fitter. A section of t h e burner is given in t h e accompanying figure a n d it is constructed as follows: T h e part C is a piece of 2 in. iron pipe about a foot long. On one end of this is screwed a cap, B , a n d on t h e other a tee, D , 2 X 31/4in. I n t h e end of t h e cap as many in. holes as possible are bored. T h e air is led into t h e burner through t h e large end of t h e tee. This air
Gas inlet
Release halve
-/--d#1-4, waif ~f f u r n a c e
FIG I 1
t h e zero mark, t h e relief valve attached t o t h e side of burette is opened, when liquid flows back and automatically sets at zero. The relief valve is made with a small piece of glass tubing with a nozzle end connected with rubber tubing t o t h e air outlet attached t o side of burette, using t h e pinchcock on t h e rubber t u b e connection. The glass tube outlet must be a nozzle of comparatively small
is supplied b y a centrifugal blower a n d is under a presin. of water. I n t o t h e side opening sure of about of t h e tee is screwed a bushing, I , 3 / 4 t o in., a n d into this is screwed t h e 1/4 in. pipe t h a t admits t h e gas. The lower, end of this pipe, J , is tapped out t o receive t h e l / 8 in. pipe E a n d t o t h e lower end of this is screwed t h e l / ~in. elbow E . .4 stopcock not shown in t h e figure regulates t h e gas supply while t h e air supply is regulated by the damper G . The burner so constructed, when properly adjusted, burns very steadily a t t h e openings at t h e end of t h e burner. There is no danger of it snapping back a n d a temperature sufficiently high for all assay purposes is easily obtained. This simple burner will doubtless be useful in heating other forms of apparatus and t h e writer sees no reason why it could not be used with a n y form of fuel gas. CHEMICAL L A B O R A T O R Y , BAKERUXIVERSITY BALDWIN C I T Y , KANSAS
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