SU1519714A1 - Foam generator - Google Patents

Abstract

The invention relates to foam extinguishing devices for fires and improves the efficiency of foaming. The foam generator contains a hollow body 1, a device 2 for supplying gas and a foaming solution, a package 3 of foaming grids, a mesh deflector 4 installed in front of it, a liquid collector 5 with nebulizers 7. The deflector is installed behind the collector at a distance of the length of the non-dissolved section of the foam-forming solution jet. 1 il.

Description

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The invention relates to fire fighting equipment, namely, to means of foam fire extinguishing.

The purpose of the invention is to increase the effectiveness of the formation of foam.

The drawing shows a foam scheme (ipa).

The foam generator consists of a hollow body 1, to the inlet of which the gas supply device 2 is tightly attached, a package 3 of foaming grids, a mesh deflector 4, one of which grids is spaced between a liquid collector 5 and a packet of foaming grids. The fluid manifold has a port 6 for supplying a foaming fluid to the foam generator. From the side of the package of foam formations. Grids on the fluid manifold n, i., The cells, sprayers 7 are of jet type, v1LH1) whose openings are direction-. 1eny towards the deflector.

The device works as follows.

The liquid is discharged along ::, the pressure through the pipe 6 enters the cavity of the pressure collector 5 and then expires on the form of free jets from the openings 7 of the nozzles. The shock interaction of each jet with the deflector mesh 4 provides the sensible splitting of the liquid into droplets, which, while continuing to move beyond the deflector mesh with a lesser speed than in a jet, form a conical spray torch, type 1) (and.

At the same time, the gas supplied by the device 2 first passes through the non-wetted mesh of the deflector, installed in the case when one grid is not enough to equalize the flow pattern of the gas flow in the cross section of the peyogenerator, and then goes to the foam generator body cavity inappropriately () in front of the deflector net wetted by the foaming liquid. Since st) ui foaming fluid moistened. the local parts of this deflector grid, the total area of which is to be ticked, not less than the total area of the deflector, it also ensures the effective alignment of the flow velocity diagram of the gas flow in the device cross section. The part of the liquid that wets the areas of the deflector grid adjacent to the sites of direct interaction of the liquid jets with it, as it is packaged by the gas stream and subsequently; 1 also participates in the foam-1 Azovan process.

Kan.ui foaming liquid oponja- south package 3 of foam-forming grids, and the gas flow, | rohod through the grids of package 3 moistened with liquid, provides a stable UO, 1 part of mechanical foam, which

in the form of a jet expires from the outlet of the body 1 of the foam generator.

The ratio between the sizes of the cells of the wetted mesh of the deflector and the nozzles of the jet nozzles, as well as the distance between them, is chosen experimentally in accordance with the required quality of spraying of the foaming liquid and the maximum uniformity of filling of the spray liquid with the liquid.

The length of the non-dissolved portion of the liquid jet L, is calculated by the equation

-CW-.

where dc is the nozzle nozzle diameter; ,,, Lp, М, N - the similarity criteria, determined from the ratios

V) d.

. /

i-n

() nrf,

N RL- "

where I is the difference between the velocities of the fluid and gas;

(Ufii - density of liquid and gas, respectively;

u | .ti - fluid viscosity coefficients

and gas, respectively; o is the coefficient of surface tension of the foaming liquid.

C. coefficients and. B, d, f depend on the design and size of the jet nebulizers.

The positive effect from the use of the invention Zack. This is due to the fact that the decrease in the axial velocity of the foaming liquid droplets before the foaming mesh package, as well as the uniform filling of single foaming liquid spray plugs with droplets, make it possible to further intensify the foaming process by increasing the velocity of the gas as it moves through the foaming grids, which in turn allows to increase the efficiency of using the foam generator for fire fighting purposes.

Claims (2)

1. A foam generator containing a hollow body, devices for supplying gas and a foaming solution, a package of foaming grids, a mesh deflector installed in front of it, and a liquid collector with nebulizers, characterized in that the deflector is installed behind the collector to increase the foaming efficiency. the distance length of the non-dissolved portion of the jet of solution. 2. A foam generator according to Claim 1, characterized in that the nozzles are jet.