GB908741A - Improvements in fire-fighting and apparatus therefor - Google Patents

Abstract

908,741. Forming foam. JAMISON, W. B. July 13, 1960 [Aug. 31, 1959; March 7, 1960], No. 24440/60. Class 14 (1). [Also in Group XXI] A fire-fighting foam generator comprises an elongated housing 10 forming a wind tunnel through which air is forced by a fan 18 with a rotor 20, the other end of the tunnel being closed by a woven fabric foam-forming net 56 on to which nozzles 32, 34 spray a solution containing a foaming agent. A foam plug builds up on the outer side of the net and is forced by the current of air in the direction of a fire, e.g. in a mine or building or to extinguish an oil fire. As shown, the net 56 is corrugated and the generator is provided with wheels or skids 54. The amount of foam generated across the net may be controlled by varying the speed of the fan or by adjusting a movable vane damper 33, Fig. 1 (not shown). In an embodiment, particularly adapted for mine roadways, the wind tunnel housing is in part of flexible material and the net, located at one end of a flexible housing, is secured by adjustable columns which are wedged between the ceiling and floor of the roadway. In order to prevent the foam plug from being forced back by back pressure, a flexible wall, e.g. of canvas, is secured around the periphery of the net and is fastened to the ceiling, floor and walls of the mine roadway. The foam is generated from 30% active ammonium lauryl sulphate dissolved in water in a proportion of about 15% active material by weight to give a concentrate in conduit 42 which is then mixed with water in conduit 40 at the rate of about 3% by volume.