GB620751A - Apparatus for generating foam for fire extinction - Google Patents

Abstract

620,751. Making foam. SAVAL APPARATENFABRIEK C. V. Nov. 16, 1945, No. 30774. Convention date, May 12, 1942. [Class 47 (ii)] Air foam is made in two stages by the admixture of water, foam former and air by a first injector, the foam formed, together with additional air, being induced into and forced along a discharge pipe by a second water jet. As shown, water under pressure from a pipe 9 is discharged as an annular jet between the pipes 1, 2, drawing in foam formed through the pipe 2 and air through the apertures 3. The foam formed passes into the passage 6, which includes baffles or mixing devices, and is drawn into a chamber 7 and forced through the discharge pipe 10 by a further water jet acting through the nozzle 8 and drawing in additional air through the apertures 8<SP>1</SP>. In a modification, a second foam-forming nozzle 1, 2, 3 is provided at the opposite side of the chamber 7, the product of both nozzles being drawn in by the nozzle 8. In three other modifications, the pipe 10 is a continuation 'of the passage 6. In one, the nozzle 8 is concentric with the passage 6 and constitutes a baffle or refiner for the primary foam. In another, the nozzle 8 has two outlets, one discharging into the inner of two nested, cup-shaped members concentric in the passage 6 to draw in the primary foam and the additional air and the second discharging towards the pipe 10 to propel the foam and induce a third air supply. In the third, a concentric extension from the nozzle 1, 2 discharges the second water jet into an oval body arranged in the passage 6 to act as a baffle and contoured internally to act as the nozzle 8. The Specification as open to inspection under Sect. 91 describes also an apparatus combining the features of the first and last constructions described above. This subject-matter does not appear in the Specification as accepted.