FR2568228A1 - Anti-explosion safety device for aerosol cans - Google Patents

Abstract

Safety device eliminating the risk of explosion of aerosol cans. This device is based on the principle of equilibrium of gas pressures inside two connected reservoirs. It consists in adding, inside the aerosol can, an empty safety reservoir 5, of convex shape on its upper surface in order to form a dome 6. This dome is provided with a safety valve 7 which opens when the previously determined critical pressure is reached in the useful part 1 of the aerosol can. Under the opening of the safety valve 7, the safety reservoir 5 and the useful part of the aerosol can 1 are connected and their pressures balance out. A considerable drop in pressure is then observed in the useful part 1. In the opposite direction, the safety reservoir 5 is itself provided in its upper face with a safety valve 10 preventing any risk of excess pressure inside the latter. The bottom of the safety reservoir, and consequently the bottom of the aerosol can, are provided with a sprayer 9 identical to that of the aerosol can itself 4 in order to empty the latter in the case of filling due to the functioning of the device. The device according to the invention is suitable for all types of aerosol cans.

Description

The subject of the present invention is, as a new industrial product, a device making it possible to eliminate the risk of explosion of aerosol cans.

 The frequency rate of serious accidents due to the explosion of aerosol cans is constantly increasing, all the more since the marketing and use of these bombs are constantly increasing.

 These cases of explosion are due to the increase in pressure inside these bombs as a result of sudden rise in temperature, brutal shock, or even crushing.

 The principle of this device is to integrate at the bottom of the aerosol can an empty tank which will be called: emergency tank.

This one, of convex shape in its upper part will be provided in its dome with a safety valve previously tared, which will open when the critical pressure is reached in the bomb, thus putting the useful part of the bomb in communication with the safety tank. The immediate effect will be the pressure balance in the two parts, thus reducing the pressure in the useful part of the aerosol can. Note that the lower the pressure, the greater the volume of the safety tank.

 A form of the invented device, is described below, and is purely indicative and not imperative or limiting.

 Referring to the appended drawing (in section view), part (i) is the normal useful volume of an aerosol can, with its plunger. (2), its spray valve (3), and its vaporizer (4 ). In the bottom of this bomb, the safety tank (5) is securely attached. The convex upper part of this tank or dome (6) is provided on its surface with a. safety valve (7) calibrated at a given pressure, previously calculated and maintained by a spring (8).

 When the pressure rises inside the useful part (1) of the bomb, and when the critical pressure is reached, the safety valve (7) opens and puts in communication the safety tank (5) and the useful part (1). The immediate effect is the equilibrium of pressure in the two parts, and therefore a significant reduction in pressure in the useful part (I.

 Note that if the safety device works, it will build up pressure and after the safety valve is back in place it will remain full. For this purpose a second vaporizer (9) will be placed under the tank in order to empty this safety tank.

 The second vaporizer ~ 9) is of the same design as a normal vaporizer, and will be used by inverting the aerosol can.

 Still for safety purposes, the safety tank (5) being full following the operation of the device, it in turn risks being subjected to a sudden increase in pressure.

This is why it is also provided on the surface of the dome (6) and in the opposite direction of the first with a safety valve (10), thus preventing the risk of overpressure. It is necessary to specify here that the two safety valves (7) and (10) will always be calibrated at the same pressure.

 It should be noted that all of the safety devices are constructed in a manner and in specific materials resistant to the various products that the aerosol can will contain.

 According to the products that are intended for the aerosol can, and in particular for the attention of polymerizers, oxidizers, paints ...

it is compulsory to evacuate the safety tank beforehand in order to avoid any contact of the product with air. In this case the calibration must take into account and will be corrected accordingly to the presence of the vacuum.

 Finally, note that the safety tank (5) is either: attached to the bottom or the edges of the bomb, or it is an integral part of the bomb and will then be stamped at the same time as its manufacture.

 It goes without saying that the object of the invention described above can only keep all of its safety properties in the case where an initial pressure of the useful volume (1) is respected identical to the pressures that the currently advocated.

It is certain that if one takes advantage of the existence of the safety tank to increase the pressure or the quantity of mixture in the useful part1 the device becomes ineffective.

 The present device is suitable for all aerosol cans, provided that one adapts its organs, and the materials of its design -tion to the products and pressures which it is desired to employ.

Claims (5)

REVDIGATIONG  1) Safety device for eliminating the risk of explosion of aerosol cans, characterized in that a safety tank (5) neutral and empty is integrated into the bottom of the bomb. This tank is provided with an upper dome (6) with a convex surface, on which a safety valve (7) 8 opens when the previously calculated limit pressure is reached in the useful part (1) of the bomb. The immediate effect is the balance of pressures inside the safety tank (5) and the useful part of the boom (1), hence a significant reduction in the pressure in the useful part. (1). The safety tank is itself provided on the dome (6) and in the opposite direction with a safety valve (10) calibrated at the same pressure as the first, thus avoiding any risk of overpressure inside the safety tank (5). The safety tank (5) is equipped on its bottom with a sprayer allowing emptying in the event of filling. This vaporizer (9) is of the same design as a normal vaporizer, such as that of the bomb (4).  2) Device according to claim 1, characterized in that the safety tank (5) can be added and welded to the bottom of the bomb, or so stamps and molded at the same time as the manufacture of the bomb.  3) Device according to any one of the preceding claims, characterized in that the safety tank (5) is previously evacuated so as to be able to allow the use of the bomb with products reacting with air: (Polymerizers, oxidants, paints ...).  4) Device according to any one of the preceding claims, characterized in that the safety valves are calibrated at equal pressures, and held in place by springs.  5) Device according to claim 3, characterized that in the event of the vacuum of the safety tank (5), the valves (7) and (10) will be calibrated at pressures taking into account the presence of vacuum.