FR2718039A1 - Diffuser cone for nozzle of carbon di-oxide fire extinguisher - Google Patents

Abstract

The diffuser (5) is conical in configuration, with the larger end open and the smaller end secured to the extinguisher discharge nozzle. The internal surface (50) of the diffuser is formed with a series of projections (51) forming obstacles to a flow of carbon dioxide gas from the extinguisher. The projections are in the form of ribs which are inclined relative to the generatrices of the cone of the diffuser, defining a helical configuration. The diffuser is formed of a plastics moulding secured to a metal insert (6) at one end, the insert having a threaded passage engageable over a threaded portion of the extinguisher nozzle.

Description

 The present invention relates to portable or wheeled carbon dioxide extinguishers and it relates more particularly to improvements made to the conical diffusion member of such extinguishers.

 It is known that the production of carbon dioxide snow is carried out by spraying carbon dioxide through a nozzle which projects this gas against the internal wall of the conical diffuser called "blunderbuss" in the technique considered.

The double problem of dry ice extinguishers consists
- 10) to make as much carbon dioxide snow as possible so that we can have a decisive action of inhibiting fire and significant cooling.

 - 20) to make a throw of sufficient range so that the person intervening on the fire does not have to get too close to it to extinguish it.

Currently on the market:
- or "blunderbusses" direct or indirect jet without grid to obtain the above mentioned range;
- or "blunderbusses" whose outlet section includes a grid to obtain the maximum possible of dry ice. The grid can be replaced by a mass of steel wool retained inside the diffuser.

 The "blunderbuss" with direct or indirect jet without grid do not allow the obtaining of a sufficient quantity of dry ice, while the "blunderbuss" with grids or steel wool have the disadvantage of a reduced range.

 The improvements which are the subject of the present invention aim to remedy these drawbacks and to allow the production of a diffuser or "blunderbuss" with indirect jet oriented on projecting means formed on the inner face of the conical diffuser.

 Under these conditions, the grid or the steel wool is removed and a significant formation of carbon dioxide snow is obtained by the internal periphery of the diffuser or "blunderbuss", while a part of the carbon dioxide constitutes a transport vector. dry ice in order to obtain a long range of the dry ice jet.

 According to a preferred embodiment of the invention, the means for producing the carbon dioxide snow consist of several ribs formed on the inner face of the conical diffuser and oriented in an inclined manner relative to the generatrices of this face. The best way to make the ribs is to give them a helical shape.

The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is likely to provide.
Fig. 1 is a partial perspective view of a dry ice extinguisher comprising a diffuser according to the invention.

 Fig. 2 is a longitudinal section of the diffuser according to the invention shown on a larger scale.

 Partially illustrated in FIG. 1 a dry ice extinguisher 1 essentially comprising a reservoir 2 containing carbon dioxide and on the outlet of which is screwed a connector 3 containing a valve not shown controlled by a handle 4 so as to project the carbon dioxide into a conical diffuser 5 or "blunderbuss".

 As illustrated in fig. 2, the "blunderbuss" 5 is produced in the form of a plastic bell having a small diameter end overmolded on a metal sleeve 6, its other larger diameter end being open.

 The socket 6 consists of a head 60 having a threaded bore 61 and a hollow body 62 provided with a blind axial hole 63 which communicates with the threaded hole 61. In the body 62 are provided radial holes 64. The connector 3 meanwhile comprises a hollow boss 30 externally threaded and which is screwed into the threaded bore 61 of the sleeve 6. A seal 7 of the O-ring type is compressed between the end of the boss 30 and the shoulder constituting the bottom of the threaded bore 61.

 According to the invention, the inner face 50 of the blunderbuss 5 is provided with a plurality of helical ribs 51 extending over practically the entire length of said inner face. In the present case, the number of ribs has been fixed at four. By way of nonlimiting example, for a diameter of the opening of the blunderbuss of around 70 mm, the height of the ribs 51 was chosen to be 8 mm.

 Of course, the ribs 51 could be replaced by straight ribs provided that they are inclined relative to the generatrices of the inner face 50 of the blunderbuss 5.

 The ribs could be replaced by projecting means of any kind constituting obstacles whose function would be equivalent to that of the aforementioned ribs.

 The carbon dioxide is propelled under pressure into the sleeve 6 from which it undergoes a deflection in the radial direction, so that the gas jets leaving the holes 64 strike the inner face 50 to cooperate with the ribs 51 which facilitate the production of dry ice.

 Part of the flow of carbon dioxide injected does not transform into carbon dioxide snow and constitutes in the center of the "blunderbuss" 5 a vector for transporting carbon dioxide snow.

So we get
- a good quantity of carbon dioxide snow sufficient to fill its rail with fire inhibition by blocking the chemical reaction of the flame and to capture the heat energy developed by the fire.

 - a good distance for propelling dry ice.

 It should moreover be understood that the foregoing description has been given only by way of example and that it in no way limits the field of the invention from which one would not depart by replacing the execution details described by all other equivalents.

Claims (3)

CLAIMS R E V E N D I C A T I O N S  1. Conical diffuser (5) of fire extinguisher (1) of dry ice of the kind comprising obstacles on which carbon dioxide is projected, characterized in that its inner face (50) is provided with projecting means (51) own to constitute said obstacles.  2. Conical diffuser according to claim 1, characterized in that the means for producing the carbon dioxide snow consist of several ribs (51) inclined relative to the generatrices of the inner face of the diffuser (5).  3. Conical diffuser according to claim 2, characterized in that the ribs (51) are of helical shape.