| 摘要 |
569,698. Fire-extinguishing. PYRENE CO., Ltd., and RATZER, A. F. Sept. 2, 1943, No. 14381. [Class 47 (ii)] Fire-extinguishing-air foam at pressures suitable for delivery through a considerable length of pipe system or fire hose, through a riser pipe on the side of an oil tank, or into the bottom of an oil tank against the pressure of oil in it, is prepared by delivering water, or a preformed solution of foam stabilising compound in water, at a pressure of at least 100 Ibs. per square inch, to jet orifices 7 to form two or more substantially parallel jets discharging into an unobstructed open end of a parallel sided or slightly flaring tube 2 into which air is entrained through openings 10 and 11 in the tube and an outer casing 1 respectively. Turbulence is imparted to the water by roughening the jet orifices 7, or by inserting a baffle plate 8 in the path of the water entering the orifices 7, to cause the jets to scatter at their fringes and occupy the whole of the crosssection of the tube 2 without intersecting one another. Where water is used, foam stabilising . compound is entrained in liquid form into the tube 2. The orifices may be from # inch to ¢ inch in diameter, and the ratio of areas of cross-section of the tube 2 and of jets at entry to the tube may vary between 5 and 15, and is preferably between 8 and 12. The length of the tube 2 should be not less than 4 nor more than 12 times the diameter. A flaring tube or chamber 5, or a delivery nozzle or hose is connected to the discharge end of the tube 2. Instead of the arrangement shown for entraining air, the end of the tube 2 may be supported at a distance from the jet orifices 7. Specifications 403,291 and 568,658 are referred to.
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