Test of Foamite System for Extinguishing Oil Fires
Tests of the Foamite system for extinguishing oil fires were given recently at the plant of the Crew-Levick Company at South Chester, Pa. Foamite was recently brought out by the MacAndrews & Forbes Company of Camden, N. J., and the tests were supervised by W. W. Walker, assistant manager of the company and inventor of a solution for quenching fires. The first test was made in a thirty foot diameter tank containing Pennslyvania crude oil, which burned very fiercely for about two minutes, the flames leaping thirty or forty feet in the air, with a large volume of dense black smoke seen only at oil fires. The heat was so intense in this short time that the tank was considerably buckled and drove the spectators back about 150 feet from the tank. The Foamite solutions which were stored in two separate storage tanks were then pumped by means of a duplex pump through two separate 2-inch lines to the Foamite mixing chamber which was arranged on the tank. The resulting foam flowed from this mixing chamber over the side of the tank on to the surface of the oil, which was approximately seven feet from the top of the tank. The foam rapidly covered the surface of the oil. The fire was quickly subdued and extinguished in a minute and a half. A second test was made consisting of the extinguishing of an improvised frame structure composed of barrels and lumber, saturated in heavy crude oil, stacked fifteen or twenty feet high so as to resemble a building partition. After this fire was burning several minutes the foam was applied from a ¾-inch nozzle through an 1 1/4-inch hose line, resulting in the extinguishing of same in two and a half minutes. The MacAndrews & Forbes Company state that the principle of the Foamite system is the same as that used in many of the chemical fire extinguishers on the market, i. e., the generation and application to the fire of carbonic acid gas which prohibits combustion, with the addition of a foam producing agent in the mixture to hold the gas in the form of bubbles so as to make its action effective on a wide surface of burning volatile material, such as a tank of oil. This foam making agent is a licorice root product (patent applied for), being a secondary extract treated by a special process and concentrated. It is shipped as a heavy viscous fluid containing 50 per cent. of moisture and is put up in barrels. It can, however, be shipped in other containers as desired, if furnished by the consumer, either drums or tank cars. Extensive experiments have shown that the following solutions used in equal quantities arc the most effective for this purpose. Solution No. 1, Foamite, 3 per cent., bi-carbonate of soda, 8 per cent; water, 89 per cent. Solution No. 2, Aluminum sulphate 11 per cent.; water, 89 per cent. The best arrangement of equipment for applying the Foamite method consists of two storage tanks, one to contain Solution No. 1, the other Solution No. 2. From each tank a suction line runs to a cylinder of a duplex pump. Two delivery lines, one for each solution, run from the pump through the yard or plant under protection, and are brought together in a large tee located outside of each oil tank. At this point the two solutions combine and re-act on each other, instantly forming a foam of exceeding fineness and toughness, which rises in the mixing chamber and overflows into the tank spreading rapidly over the surface of the oil. The mixing chamber is of a suitably large capacity to allow for the expansion due to the transformation of the solution into gas and foam and to reduce the velocity of the transformed material, so that the foam will flow quietly onto the surface of the oil without disturbing the surface or mixing with the oil. The size and shape of the mouth of the discharge chamber is such as to deliver a thin, wide layer of Foamite on to the surface of the oil.