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Burning of Two Hundred Thousand Pounds of Picric Acid at Sparta, Wisconsin',' By Charles E. Munroe X*TroN*L RFSEARCB COUNCZL.
W~as~rraorox, D. C.
to Sparta as a "solid idammable material" containing 10 per cent of moisture. It was accepted by the Ordnance Department, U. S.A., under Specifications No. GE-317, which, among other characteristics. required that "it must be of such a degree of
Fro. l-oprr~ Snm TYP. OP M I ~ Z I N B
fineness that all shall pass through a 1Zmesh screen having openings of 0.058-in. and wire of 0.025-in. diameter." The barrels were stacked in the magazine on end and three high as close together as possible. Originally this magazine contained 217,880 Ibs. of picric acid, but deliveries of part of the stock had been made, so that a t the time the fire broke out in this magazine there were but 500 bbls. or 200,ooO lbs. of picric acid stored there. The deliveries had been made from the center of the pile so that as one approached the magazine on the south or north side an aisle was to be observed between the barrels which space had previously been occupied by some forty-five barrels. The picric acid in this magazine was a part of the surplus war material that had hecu allotted to the Department of Agriculture for distribution by the Bureau of Public Roads in industrial projects. and it was being conveyed as fast as practicable t o the plant of M. J. Connolly & Company within the reservation where it was cartridged and packed under contract with the Bureau of Public Roads. FIREPROTECTION Each magazine was entirely surrounded by a fire break, 50 ft. in width, made by plowing. Barrels of water and buckets
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U.S.
Received March 16, 1922.
Published by permission of the Chid of the Ordnance Department, A.
June, 1922
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were placed near a t hand outside each magazine and supplies of shovels, with which to smother fires by covering them with sandy soil, and brooms, for beating out brush and grass fires, bere kept a t convenient points in the area. A chemical fire engine was included in the equipment of the depot, and the area was patrolled. CONDITION OF PACKAGES
It is evident that the picric acid packages, stored as described above in magazines No. 263 and No. 264, were exposed freely to the wind and to an extent directly to the sun. Owing to extreme heat and dryness during the summer, crevices developed between the staves of a number of the barrels, thus permitting the contents to become more or less dried out. To ascertain to what extent this may have occurred three barrels were taken from different positions horizontally and vertically in magazine No. 264 and the moisture content determined in samples taken from the top, middle, and bottom of each barrel. The barrels were taken as follows : (1) south side (first barrel) ; (2) middle (second barrel) ; (3) north side (third barrel). The results of the tests of moisture contents were as follows: MOISTURE CONTENTS OF EXPOSED BARRELS OF PICRIC ACID BARREL TOP MIDDLE BOTTOM hT0. PER CENT O F MOISTURE 1 0 30 0.60 1.20 2 1.47 7.92 8.15 3 2.93 7.40 9.20
As a consequence of this opening up of the staves of the barrels and the drying out of their contents the finely divided material tended to sift out, especially as the barrels were disturbed.
CIRCUMSTANCES OF THE FIRE Shortly before 3:50 P.M., on September 28, 1921, a &ton artillery tractor with two 3-ton trailers attached and carrying a crew of three laborers, engaged in transporting the barrels of picric acid from the magazines to the cartridging plant, approached magazine hTo. 263 from the southeast, ran along the south side of the magazine, and at about 6 to 8 f t . from it, until it reached the center of the building, when the train was stopped with the tractor turned out so that i t was about 10 ft. from the magazine. The wind was a t this time blowing from southeast at about 18 mi. per hr. As the train was coming to a stop a man on the trailer discovered fire in or beside the aisle where barrels of picric acid had been taken out and where there was picric acid powder on the boards and grass. He immediately grabbed a shovel and threw sand on the fire but the fire spread so fast and became so hot he abandoned his effort and the crew fled. At about this time the commanding officer, being then engaged a t the loading yard a t a distance of about 880 yds. to the south of magazine No. 263, had his attention called to the smoke arising. He a t once ordered the fire alarm given, ordered all men present to proceed to the fire, and the fire fighting equipment to be assembled there, and proceeded himself at once by motor truck. On arrival he found about fifty men available, equipped with brooms and shovels, and also the chemical fire engine, but as the fire in magazine No. 263 was then under such headway that it could not be approached he disposed his force in a semicircle to the north of this magazine to beat out the brush fires, build back fires, and the like, and he proceeded toward magazine No. 264, directing the extinction of grass and brush fires as he proceeded, until when he was within three feet of magazine No. 264, which was of the same construction and arrangement as No. 263, but contained 217,880 lbs. of picric acid, there was a flare and approximately one-fifth of the north section of the magazine burst into flames. Immediately some fifteen men responded to a call for aid and, entering the magazine, rolled out burning barrels of picric acid and by means of the chemical engine, use of sand, and beating, got the fire under control.
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It was then discovered that fire was still burning under the floor of this magazine so other barrels were removed, the flooring torn up, the fire there extinguished, and the magazine and its contents saved.
Loss AND CASUALTIES The loss was confined to magazine No. 263 and its contents. The value of the picric acid for its allotted use was estimated a t $40.01)0.
~ - _ I _ _ _
FIG.3-MAGAZINE
NO.
263
DURING THE
FIRE
Several of the men fighting the fire were unpleasantly affected by the smoke and fumes which they inhaled, the general complaint being of irritation of the lungs. Two were sufficiently overcome to be taken to a hospital, but i t is not improbable that they were suffering also from undue physical exertion. All soon recovered. S O U R C E OF IGNITION
All other sources having been inquired into and eliminated, the source of ignition was found in red-hot carbon forced from the exhaust of the tractor and carried forward by the wind to exposed picric acid. I t was found that the approach to the magazine was quite an up-grade through heavy sand and that the tractor came up “in second” with the motor laboring hard. PHENOMENA OBSERVED
The flames from magazine iVo. 263 reached a height of 35 to 40 f t . They were extremely quick, sharp, bright, and of a reddish color. The heat was so intense that the metal in the roof and the barrel hoops were melted and a large part completely burned. There is evidence to show that melted iron ran through picric acid, as globules of the metal were found on the sand. At first there was a great volume of heavy black smoke but as the temperature increased the carbon combustion was more complete. The effect was no doubt modified by the burning of the wood of the barrels and by the water present in the picric acid. During the burning of magazine No. 263, grass fires were seen to start a t points 800 f t . from the magazine and considerably to one side of the line of the wind. This may be accounted for on the theory that large volumes of heated gases from the fire caused whorls of suflicient size and intensity to throw sparks and burning brands a considerable distance to one side. The intense heat caused such an inflow of air that odors could not be detected by one standing as close to the fire as the heat permitted. The roar during the fire was so loud that decrepitation or deflagation reports, such as usually accompany the burning of small quantities of picric acid, could not be distinguished. Toward the end of the fire there were occasional small “reports” of about the loudness of a 12-gage shot gun report. These were observed to result from gas coniined under unburned picric acid and fallen roof and when these “puffs” occurred picric acid was
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tossed up 5 or 6 ft. These “puffs” came from beneath the almost completely burned mass. At magazine No. 264 the smoke immediately on emission from the picric acid was black, though less dense than that from burning crude petroleum, but above this the cloud was of a decided yellow color. The gas or vapors a t this magazine were very pungent, sharply acrid, and very irritating to the mucous membrane of the nose and lungs. It was the men laboring in this magazine who experienced ill effectsfrom the inhalation of these products, which gave rise to choking and strangulation.
ACKNOWLEDGMENT The writer’s sincere thanks are due Major A. J. Stuart, Ordnance Department, U. S. A., for giving him access to the official reports on this event.
The Geography of Electrochemistry’ By W.S. Landis AMERICANCYANA~IID Co.. 511 FIFTHAvs., NEWYORL,N. Y.
HE two main applications of the electric curLent which
T
are of value to the chemist are as a convenient source of heat and as a powerful decomposing agent. Many factors apply in a comparison of the cost of electric heat with combustion heat. The fact must be considered (and is often overlooked) that electrically generated heat is released in intimate contact with the absorber, a t rates balanced against rates o€ absorption, and in any desired atmosphere, It permits the attainment of high temperatures on a scale unknown to the combustion engineer. The combustion of a ton of high-grade bituminous coal yields approximately the same number of heat units as a kilowatt year of electricity. The losses OF heat in flue gases, careless admission of air, incomplete combustion, and radiation from large cornbustion chambers increase the relative cost of combustion heat. Modern steam power plants operating large units convert the potential energy of coal into electrical energy a t thermal efficiencies approximating twenty per cent. This relationship, coupled with the highly efficient conversion of electric energy into usefully applied heat, does not in any sense exclude the steam-electric combination as a competitor of direct firing, and there are many other advantages to help pay the heavier overhead. In different parts of the world different relationships exist. I n parts of Italy favored with water power developments the kilowatt year is produced rather cheaply and many installations have found it cheaper to generate steam by submerging a resistor in a boiler than to burn expensive imported coal. Norway also possesses no coal, but has abundant hydraulically generated power averaging less than $12 per kilowatt year. A plan has actually been worked out for heating all the houses in Bergen from central hot water storage plants, the water itself being electrically heated. The sole domestic metallurgical fuel of Sweden is charcoal, which is becoming more scarce each year. I n the manufacture of pig iron in the blast furnace approximately one ton of charcoal is required per ton of pig iron produced. Of this, one-third is used in chemical reduction of the iron ore and two-thirds are burned up to supply heat for operating the furnace. Onefourth of a kilowatt year per ton of pig iron is sufficient to keep the furnace hot, and when, ten years ago, the price of charcoal rose to a point where a ton OF charcoal cost more than three1 Abstract of a paper presented before the Cleveland Sections of the American Institute of Electrical Engineers and of the American Chemical Society, Cleveland, Ohio, February 16, 1922.
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eighths of a kilowatt year, the old blast furnaces were supplanted by electric furnaces. I n other words, when the kilowatt year can be purchased for the same price as two and a half tons of charcoal or coke, the blast furnace becomes obsolete, Norway, Italy, Sweden, and Japan have made the change, and India, Brazil, and our own Pacific States are contemplating the adoption of the electric furnace in the iron industry. The mere fact that low cost electric power exists somewhere does not always make i t cheap. Raw materials, labor, and transportation are often more important factors than electric energy. Norway possesses cheap power. She has little else in the shape of raw materials and must import supplies. Her labor is scarce, fairly high priced, and of uncertain temperament. She has built up a great nitrogen industry using only air, water, and electricity, and holds a practical monopoly of this type of process. The carbide and cyanamide processes have failed for several reasons, chiefly because of high cost of imported coal and coke and long hauls on limestone. Her aluminium industry is undergoing a change with the hope of utilizing a local feldspar instead of the usual French ores. Her steel industry has remained small. Sweden has an electric iron and steel industry of fair proportions, but is handicapped by lack of fuel. Swedish ores will continue to be exported in the face of available electric power for home manufacture. Germany has developed a considerable electrochemical industry in spite of very limited hydropower. Brown coal efficiently burned under boilers is operating melting furnaces, caustic and cyanamide plants, steel furnace, and other electrochemical processes. She is quite a factor in this industry, certainly leading Europe, and yet has a potential hydroelectric power development of less than one and one-half million horse power. France possesses great possibilities of hydro development, some of it already available. She possesses the start of a large electrochemical industry, early entering the fields of electrosteel, aluminium, caustic, and fine chemicals. Her coal supply is deficient but other raw materials are plentiful, as are also transportation and labor. Neither Switzerland nor Italy possesses coal deposits of consequence; yet both are well supplied with water power. Switzerland early started carbide and ferro-alloy production, but demands of the power for manufacturing and transportation will always hold back the electrochemical industry. Italy, on the other hand, is just a t the beginning of important developments. Iron, steel, nitrogen fixation, and chemicals will receive a great deal of attention in there. Russia possesses few important hydroelectric possibilities and will be years recovering from her present political condition. Finland possesses great hydro possibilities and may develop a small industry, but raw materials are not plentiful and the country lacks all the real fundamentals of a manufacturing community. England, on steam power, has always been foremost in electrochemical development. She has been the birthplace of many industries which have moved to more favored locations. The rising costs of fuel in England will not revive some of these departed industries, but steam power costs are decreasing slowly with the larger units being developed and the life of the industry as now existent will be prolonged. The metal working industries can easily survive on steam, and electrolytic refining is gaining a strong foothold. The water power resources, while not large, are fair, and are being closely investigated. Asia is of little present interest to us. Siberia has no remarkable water power possibilities, in fact very meager ones. She has no industrial foundation to build on and may be dismissed from consideration for a long time. It takes more than water and a drop in elevation to start an electrochemical plant.
