US 3070172 A
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United States Patent 3,070,172 PROCESSES FOR EXTINGUISI-HNG FIRES Sam R. Carter, Jr., 1521 Roma Ave. NE., Albuquerque, N. Mex. No Drawing. Filed Nov. 19, 1958, Ser. No. 774,851
4 Claims. (Cl. 169-1) This invention relates to a new and improved process for extinguishing fires, and, more particularly, high-ternperature and confined fires such as oil well fires, oil pit fires and the like.
Objects of the invention are: to provide a process for extinguishing or controlling fires of the character described in which there is introduced into the fire a bomb-like container carrying a quantity of a material such, for example, as carbon dioxide, under such conditions that the heat of the fire causes the pressure within the container to rise rapidly to a predetermined point at which the container is ruptured with explosive force of a character and violence effective to suppress the fire; to provide such a process in which the rapid expansion of gaseous material contained within the bomb-like extinguisher at the moment of rupture causes a chilling of the expanding gas which is effective to suppress the fire; and to provide such a process in which the material carried by the bomb-like container is of a non-flammable nature effective to blanket and suppress the fire.
Other objects of the invention will in part and will in part appear hereinafter.
The invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description of a preferred embodiment thereof.
Heretofore, in the control or extinguishrnent of fires it has been customary to employ extinguishers containing carbon dioxide and so constructed that, by opening a valve, carbon dioxide gas under pressure is forced from the extinguisher through a nozzle or horn of such a nature and under such conditions that carbon dioxide snow is formed which is sprayed onto the fire or carried to it by a stream of carbon dioxide gas. The snow is then volatilized by the fire and a blanket of carbon dioxide in gaseous form provided which smothers the blaze. Such a method of control has been found inadequate for hightemperature fires originating in confined areas difficult of access such as oil well fires, oil pit fires and the like. '1 have found that a very effective method of extinguishing and controlling the spread of such fires is to introduce into the heart of the blaze a bomb-like container which will explode violently when the pressure within the container reaches a predetermined point. The container preferably carries carbon dioxide, or some other material which is eifective to blanket the fire and cut off oxygen therefrom.
I believe that the method of the present invention combines three effective fire suppressing mechanisms for the first time: (1) the explosive effect of the bomb-like container employed in the present invention appears to have an action comparable to a mechanical scattering or heating down of the blaze; (2) the chilling effect of the rapid expansion of the gas expelled by the container employed in the present invention, at the moment of rupture, is effective to lower rapidly the temperature of the burning material and thus control the blaze; and (3) the blanketing effect of the gaseous carbon dioxide is effective to suppress the blaze.
be obvious ice Moreover, the bomb-like extinguishers employed in the practice of the present invention may be introduced from a distance into the heart of the burning area by being thrown or catapulted thereinto and they may thus be readily employed under conditions which make close approach to the burning area diflicult if not impossible.
In one form of conventional fire extinguishing apparatus, a steel container is provided which is adapted to store carbon dioxide under relatively high pressure. The container is provided with a valve-controlled opening to which is affixed a flexible hose at the end of which is a horn or snow-producing shield. Such fire extinguishers are shown and described, for example, in United States Patents Nos. 2,242,399 to Kurth and 2,569,490 to Newman. The steel containers employed in these fire extinguishing devices are preferably constructed so as to withstand relatively high pressure and are preferably of such size as to have an interior volume such that, at room temperature, the solid carbon dioxide with which they are initially charge will vaporize, building up a pressure within the container in excess of the pressure at which solid carbon dioxide will be converted into liquid carbon dioxide. It is believed that room-temperature pressures within conventional fire extinguishing apparatus of the type described are of the order of 800 to 850 lbs. per square inch. The steel containers employed in these conventional fire extinguishers are usually so constructed as to withstand considerably increased pressures of the order, for example, of approximately 1800 lbs. per square inch and these containers, in slightly modified form, may be adapted for the practice of the present invention, although preferably bomb-like containers of greater volume, and having greater resistance to pressure, are employed.
In any case, in the practice of the present invention a container, preferably of steel, is charged with solid carbon dioxide and then tightly sealed. No vents or valves are provided and the container may preferably be so constructed as to resist rupture at pressures less than 5 000 lbs. per square inch, for example, although, as has previously been indicated, containers which are less resistant to rupture may satisfactorily be employed under certain conditions. The containers of the present invention are preferably of fairly large size, of a volume, for example, of 50 cubic feet, .so as to carry initial charges of fairly large amounts of solid carbon dioxide which at room temperature will be converted into a relatively large volume of gaseous carbon dioxide and some liquid carbon dioxide. The vapor pressure of liquid carbon dioxide rises very rapidly with increasing temperature, reaching approximately 1000 atmospheres at temperatures of the order of C. Preferably, the containers employed in the practice of the present invention should be so constructed as to resist rupture when introduced into a fire until the internal pressure has built up to a maximum consistent with reasonable container costs. Best results, for example, have been obtained where the containers employed in the practice of the invention have been constructed so as to withstand rupture at internal pressures below 5000 lbs. per square inch.
In the practice of the present invention, the charged, tightly sealed container is introduced directly into the fire, for example, by being dropped, thrown or catapulted into the blaze. The heat of the fire rapidly raises the pressure within the container to the point at which the container ruptures, and at this point the container explodes much in the manner in which a bomb explodes. The gaseous contents of the container expand rapidly, thus chilling the surrounding area. Some, at least, of the liquid contents of the container is apparently converted into carbon dioxide snow which is scattered over the blaze and lowers the temperature of the burning material with which it comes in contact. It is rapidly vaporized and combines with the volume of gas expelled from the container to provide a blanket which in confined areas serves tov smother and extinguish the blaze. Moreover, it appears that the violent explosion occasioned by the sudden rupture of the container at high pressure acts much as does a mechanical beating down of the blaze. In any event, the explosion appears to aid effectively in the suppression of the fire.
It is intended that the process of the present invention may be employed with containers of varying size, from those which are small and which may be manually thrown or dropped into the blaze in the manner in which a grenade, for example, is thrown, to those which are so large that they must be mechanically catapulted into the fire. Where small containers are employed, several may be used but best results have been obtained from the use of relatively large containers of such volume that a single explosion will adequately blanket the area of the fire. The process of the present invention has been found particularly efiective as a method of suppressing oil fires such as those which may arise in oil pits or other confined areas, when the larger containers are employed.
Since certain changes may be made in the above process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.
What is claimed is:
1. The fire-extinguishing method which comprises confining carbon dioxide in a rupturable container adapted to withstand internal pressures of the order of at least 1800 lbs. per square inch, positioning said container in close proximity to the fire, whereby the gaseous pressure wthin the container is caused to rise rapidly, and maintaining said container in said close proximity to the fire until it ruptures, whereby the suddenly expanding gas expelled from said container is caused to exert an explosive impact on the burning substance in said fire.
2. The fire-extinguishing method which comprises bringing into close proximity with the fire a bomb-like, rupturable container having confined therein a quantity of carbon dioxide and causing said container to rupture only when the gaseous pressure therein exceeds at least 1800 lbs. per square inch.
3. The fire-extinguishing method which comprises bringing into close proximity with the fire a bomb-like, rupturable container having confined therein a quantity of carbon dioxide, in both liquid and gaseous form, and causing said container to rupture only when the gaseous pressure therein exceeds at least 1800 lbs. per square inch.
4. The fire-extinguishing method which comprises bringing into close proximity with the fire a bomb-like, rupturable container having confined therein a quantity of carbon dioxide, in both liquid and gaseous form, and causing said container to rupture only when the gaseous pressure therein exceeds at least 1800 lbs. per square inch, with simultaneous rapid expansion and chilling of the gas expelled from said container, formation of carbon dioxide snow and explosive impact of gas expelled from said container on the burning substance in said fire.
References Cited in the file of this patent UNITED STATES PATENTS 328,319 Le Moyne Oct. 13, 1885