FR2720652A1 - Fire extinguishing fluid ejector and diffuser - Google Patents

Abstract

The ejector/diffuser consists of a tangential or axial flow turbine (5) with its rotation designed to slow down and diffuse the fluid, e.g. liquid carbon anhydride, inside a confined space (4). The turbine is connected to the end of a tube (3) which links it to a storage tank (1) of the fluid, and is coupled mechanically to a centrifugal alarm (6) which indicates that the extinguisher is functioning.

Description

 The present invention relates to a device for extinguishing a fire in a confined space according to a known method of spraying an inerting fluid, the most common of which is the liquefied carbon dioxide contained in a tank.

The fluid is released by a valve and led into the volute by a pipe whose end is connected to one or more diffusion nozzles.

 This action has a double effect. On the one hand, it reduces the oxygen level in the air to a value below the combustion threshold.

On the other hand, the expansion at the level of the projection nozzles lowers the temperature of the hearth.

This last action promotes extinction and reduces the risk of resumption of combustion.

This process requires a first rapid flooding phase of the enclosure followed by a phase of maintaining the design or not, for a period determined by experience and depending on the nature of the hearth.

 In order to obtain optimal diffusion of the neutralizing agent, the spraying is preferably carried out on several nozzles distributed in the volume.

The nozzle outlet nozzles must be carefully defined according to precise criteria so that the expansion does not cause the outlet ports to be blocked by icing.

This result can also be obtained by screens made of porous material or metallic foams which reduce the speed of projection.

These means are only effective over a limited range in speed, duration of projection and phase of the fluid, which gradually changes from the liquid state to the gaseous state as the tank is emptied.

 The device according to the invention makes it possible to improve the diffusion characteristics, while eliminating the risks of icing.

 I1 is characterized in that the projection means consists of a turbine with axial or tangential flow, disposed at the end of the fluid distribution duct, the rotation of said turbine induced by the passage of the fluid produces a slowdown and a turbulent diffusion of the flow, at the outlet orifice. This effect is obtained for all states of liquid, gas or biphasic projection. Furthermore, the device according to the invention achieves a dynamic slowdown of the fluid, which has the effect of reducing the risk of icing without requiring critical machining of the nozzles.

 According to a variant, the turbine is mechanically coupled to a centrifugal warning device, which informs of the operation of the device, in particular when it is an automatic equipment.

This variant constitutes the new application of a known pneumatic horn device. The accompanying drawing illustrates the invention. I1 represents the device which includes the pressurized fluid reservoir (1) the control valve (2) the fluid supply duct (3) in the enclosure (4) the turbine (5) mounted at the end of the conduit (3) which is coupled to the horn (6).

 The device according to the invention is particularly intended for the projection and diffusion of extinguishing fluids, in a volume representing fire risks.

Claims (2)

 1) Device for projecting and diffusing fire extinguishing fluid into a confined volume (4) characterized in that it consists of a tangential or axial flow turbine (5) whose rotation is taken advantage of to slow down and diffuse said fluid inside the volume, said turbine being connected to the end of the supply pipe (3) of the fluid stored in the tank (1).  2) Device according to claim 1, characterized in that the turbine (5) is mechanically coupled to a centrifugal alarm (6) which signals the operation of the device.