T H E J O U R N A L OF I N D U 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
934
tractions were made with two I O cc. portions of chloroform f r o m 50 cc. of aqueous solution, made alkaline with 0.5 cc. of N H 4 0 H : TABLEXVIII Wt. strychnine used 0.1594 0.1594
Total wt. found 0.1623 0.1622
Corr. for residue in chlor. 0.0015 0.0015
Corrected Percentage wt. found 0.1608 100.8 0.1607 100.8
-
Calculated,
100.0
Using 50 cc. of water, 0.5 cc. of TU”40H, one I O cc. portion of t h e 3 : I ether-chloroform mixture a n d 4 cc. of ether (allowed for saturating t h e water) for t h e first extraction a n d IO cc. of t h e mixture for t h e second extraction, t h e following results were reached: TABLEXIX Wt. strychnine used 0 0638 0.0626
Total Wt.
found 0.0582 0.0570
Corr. for residue in ether-chlor. 0.0010 0.0010
Corrected Percentage Wt. found 0.0572 89.7 0.0560 89.5
-
Calculated, 9 0 . 8
We must conclude, then, t h a t chloroform alone is t o be preferred in this extraction. It is possible t h a t some authors may have other reasons for using t h e mixture.
t
Vol. 6, No.
CONCLUSIONS
I-The distribution coefficients of a number of substances have been studied with a view t o finding t h e best set of conditions under which t o make extractions. 11-It has been shown t h a t chloroform serves t o extract aconitine a n d codeine from aqueous solution better t h a n ether. Chloroform extracts strychnine better t h a n mixtures of chloroform a n d ether, as suggested by many authors, while ether serves very satisfactorily for t h e extraction of cocaine alkaloid. 111-The distribution of citral between lemon oil a n d 45 per cent a n d 5 0 per cent alcohol has been discussed from this point of view. IV-A s t u d y of t h e extraction methods for morphine has been made a n d none has been found t o be short a n d accurate for t h e analytical chemist. V-Under morphine, a use of t h e distribution ratio. has been suggested t o avoid laborious a n d continued extractions. SOUTHDAKOTA FOODAND DRUGDEPARTMENT VERMILION, SOUTHDAXOTA
I
LABORATORY AND PLANT THE EXPLOSIBLITY OF GRAIN DUSTS1 By HAROLD H. BROWN Received October 8, 1914
As a result of a number of explosions in grain mills a n d industrial plants in this country a n d in Europe, and more especially as a result of a n explosion in a feedgrinding plant a t Buffalo, New York, in June, 1913, b y which thirty-three men lost their lives a n d upwards of seventy were injured, a cooperative movement between milling interests generally a n d t h e Bureau of Mines was arranged for t h e purpose of makinga scientific s t u d y of t h e explosibility of grain dusts, a n d of methods pertaining t o t h e prevention of such explosions. T h e milling interests were represented in t h e conduct of t h e work b y Messrs. Lawrence E . Harmon, President of Buffalo Cereal Company; F r a n k F. Henry, Manager Washburn-Crosby Company; a n d George P. Urban, Secr e t a r y George Urban Milling Company, all of Buffalo, New York. T h i s work was started August I , 1913, being placed under t h e direction of Prof. George A. Hulett, Chief Chemist of t h e Bureau of Mines. David J. Price was assigned t o t h e field-engineering work, a n d o n February I , 1914, Dr. H. H. Brown began a laborat o r y s t u d y of t h e problem. During t h e preliminary s t u d y thirteen explosions were investigated which have occurred since 1903. Three of these took place in Iowa, three in New York, t w o in Illinois, a n d one in Vermont, Indiana, Kansas, Ohio a n d Texas. These explosions were classified among t h e various lines of milling as follows: Cereal mills, 4 ; elevators, 3 ; feed mills, 2 ; starch factories, z ; glucose factory, I ; flour mill, I . I t is reported t h a t , a s a result of these explosions, a t least 7 8 men were 1 Abstract of a Preliminary Report by David J. Price and Harold H. Brown, published by the Millers’ Committee of Buffalo, N. Y .
II
killed a n d 119 injured. T h e t o t a l damage t o property exceeded $z,ooo,ooo. Since 1911 four explosions have occurred in Europe, t w o in dextrine works, one in a proveqder mill, grinding peas, beans, a n d wheat, a n d one in a linseed mill. AS a result 47 men were killed a n d 119 injured. I n order t o make a laboratory s t u d y of t h e problem, samples of t h e following dusts were collected, a n d t h e conditions under which t h e y were produced were studied: I-Dusts produced during t h e process of elevating a n d handling grain, a n d known a s elevator dusts 2-Wheat-flour dusts from rolls, bolters, purifiers, conveyors, packing machines, etc. 3-Wheat-flour dusts from beams, rafters, elevator heads, etc. 4-Dusts produced during t h e cleaning of oats 5-Dust from grinding white corn 6-Dust from grinding yellow corn 7-Dust from grinding o a t hulls 8-Oatmeal dust from packing machines 9-Floor dusts from elevator sweeping Io-Oat-groat dusts after aspirator These dusts were first analyzed i n t h e United States Food a n d Drug Laboratory, Chicago. Determination of moisture, ether extract, proteins, crude fiber, ash, a n d nitrogen-free extract or carbohydrates, were made, t o ascertain, not only t h e chemical n a t u r e of t h e materials, b u t also wherein t h e y might differ from t h e grains from which t h e y originated. Experiments were t h e n started i n t h e Bureau of Mines, Pittsburgh, t o determine t h e ignition-temperat u r e of these dusts, using t h e method of Wheeler.‘ This consisted in forcing t h e dust i n a cloud through a 1 “Report on the Inflammability and Capacity for Transmitting Explosions of Carbonaceous Dust, Liable to^ Be Generated On Premises. under the Factory and Workshop Acts.” 1913.
R. V. Wheeler.
Nov.. 1 9 r q
T H E J O U R N A L OF I N U C S T R I A L A Z j D E N G I N E E R I N G C H E M I S T R Y
inches in diameter and j j inches long, glass tube, against a heated platinum coil, which was I j.7 j inches from one end of t h e tuhc. The temperature of t h e coil \cas obtained by a P t - P t R h thermocouple, having its hot junction within t h e quartz t u b e upon which the coil w a s wound. Gsini! this method, T'iliecier
E ~ ~ ~ W . , ~~R E,L F ~~ ' A,.PAR~TL.S-KO. S~ ~ , ~ hi, D U S T P U O I l.'*RS.r
YBLLOW
While t h i s work gave the relative ignition-temperatures i t did not give t h e lowest temperature of ignition or t h e relativr inflammability. This latter was determincd by means of a n apparatus developed in t h e Hurcau of Mines. I t consists oi a n explosion flask of about 1400 cc. (85.36 cubic inches) capacity having
actual temperature on t h e outside of t h e coil. The dust is ignited liv the heated coil a n d a pressure developed within t h e flask, which is registered by t h e gauge. The relative inflammability a t a n y temperature is measured by t h e diffcrence in t h e pressures developed within the flask. Determinations were made of pressures developed C., hy t h e different dusts, a s received a n d dried at when they were forced against t h e coil heated to I Z O O ~ , i1oo0, IOOO' a n d 900" C . As no standard has heen taken f o r carbonaceous dusts, other t h a n coal dust, Pittsburgh standard coal dust, which is very constant in its properties, a n d which is used a s a standard in t h e Bureau of Mines, was taken a s a standard a n d all determinations r u n against i t a n d checked against t h e average value obtained for it a t each temperature. Tables a n d curves are given which indicate t h a t most, if not all, t h e grain dusts are more inflammable t h a n Pittsburgh standard coal dust, higher pressures being developed in most cases, and especially so at t h e lower temperatures. T h e results also seem t o indicate t h a t t h e dusts f r o m oats a n d yellow corn are m i r e inflammable t h a n those from wheat or other grain, However, t h e results are only very preliminary a n d i t is possible t h a t later work will change this supposition, a n d probably will change t h e curves; extending them to still lower temperatures. It is interesting t o note t h e difference in t h e inflammability of t h e dried a n d undried dusts. In nearly every case t h e pressure developed was appreci;rhly increased after drying. Three are especially noticeable. These gave 0.5 pound pressure or less a t 1200' when undried a n d over 8.0 pounds when dried, Pittsburgh standard coal dust giving 9.0 pounds a t t h e same temperature. This is a n indication of what may be expected when t h e humidity of t h e air is decreased. Experiments carried ont by the Bureaii of Mines' have shown t h a t a n explosion could be produced when there was only 0 . 0 3 2 ounce of coal dust suspended in each cubic foot of air, or one pound in 500 cubic feet of air. In t h e experiments of M. J. Taffnnel, a t t h e Lievin Experiment Station in Prance, in one instance as low a weight as 0 , 0 2 3 ounce of coal dust per cubic foot of space was sufficient t o produce a n
C ~ ~ N - - L I S O c. ' (2102- IC)
R K E A h rN Dnu MILLIN
