US1839658A - Method of extinguishing fires - Google Patents

Description

Patented Jan. 5, 1932 UNITE STATES LODIAS J'. DUGAS, OF CHICAGO, ILLINOIS, ASSIGNOR '10 DU-GAS FIRE EXTINGUISHER 4 CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE METHOD OF EXTINGUISHING- FIRES Application led October 30, 1929. Serial No. 403,381.

This invention relates to a method of 'extinguishing fires and more particularly to a method wherein a gaseous mixture containing a dry fire extinguishing powder is employed for ghting fires.

It has heretofore been proposed to blow a fire extinguishing powder or a smoth'ering substance such as sand or the like onto fires for the purpose of extinguishing them. Such proposed methods have not, however, come into practical use for various reasons. Chief among these reasons have been the difficulty encountered in devising a fire extinguishing powder that would not cake or hang up in the extinguisher container and also the diiiiculty of obtaining a continuously uniform mixture of the chemical and gas. The tendency is for the dry re extinguishing powder to be ejected in an irregular and uncontrolla- 'ble manner. Furthermore. it has never heretofore been thought possible to fight really large fires with a dry fire extinguishing powder, since no method nor means has previously been devised for efectively delivering the fire extinguishing powder at any considerable distance from the point of discharge. Consequently, the only use to which dry chemicals have been put up to the present time has been in fighting small tires, either by throwing the dry chemical by hand from a small tube onto the iire or else directing a feeble and irregular gaseous stream containing the chemical against the fire.

It is therefore an object of this invention to provide an improved method of extinguishing fires wherein a continuously uniform gaseous mixture containing a freely flowing tire extinguishing powder is delivered Y at high pressure and at great velocity directly against the conflagration, the operator being protected from the heat of the fire by the protective screen of gas and powder delivered against the fire.

It is a further important object of this invention to provide a method of extinguishing very large fires, and especially oil fires, by the combined effect of a non-fire supporting gas and a powdered chemical adapted on being heated to form a fire smothering gas.

Other and further important objects of this invention will become apparent from the disclosures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 illustrates the method of extinguishing fires according to my invention.

Figure 2 is an elevational view of appara- 60 tus adapted for use with my method.

Apparatus suitable for use with my method of extinguishing fires comprises a fire extinguisher container 1 and a gas cylinder 2 connected thereto by piping 3, the container 1 and cylinder 2 being preferably mounted upon a wheeled truck, indicated as a whole by the reference numeral 4'. It will be understood, however, that other designs and sizes of apparatus, either portable or stationary, may be employed. Fire extinguishers of a suitable type are more specifically described and claimed in my copending application entitled Fire extinguisher container, Serial No. 325,675, filed December 13, 1928.

The cylinder 2 is preferably charged with nitrogen gas under about 1800 lbs. per sq. ign-'pessilthough pressuresfrom 10() lbs. up to over 2000 lbs. may beutilized satisfaetorily. Also other gases than nitrogen 80 may be employed, such as carbon di'owxide.

The fire extinguishingclie'nicawmc'itained in receptacle 1 is a freely iiowing powder adapted when heated to generate a ire smothering gas and anon-volatile residual flux that coats the burning object and prevents reignition thereof. A suitable type of fire extinguishing powder is disclosed in the copending application of D. Julian Block, entitled Composition of matter, Serial No. 307.785, filed September 22, 1928. The chemical therein disclosed consists principally of sodium bicarbonate and a substance adapted to render the bicarbonate non-packing and non-hygroscopic, such as a metallic salt of a fatty acid, for instance, magnesium stearate. A fire extinguishing chemical of this type does not become wet when moisture is present nor does it pack or hang up in the container but remains under all conditions in an apparently dry, free flowing state.

The connecting piping 3 between the gas cylinder 2 and the extinguisher container 1 suitably includes a valve 5 and a second valve 6 for controlling the flow of gas into the container 1, pressure gages 7 and 8 being positioned in said connecting piping 3 for indicating the pressure of the gas in the cylinder 2 and the pressure of the gas delivered into the container 1. The gas mixes with and picks upthe dry chemical contained in the receptacle 1 and is delivered therefrom through a flexible hose 9 having at its end a valve controlled nozzle 10, through which the gaseous mixture containing the uniformly distributed dry chemical is discharged against the scene of confiagration. Preferably, the nozzle 10 is provided with a liaring, comparatively flat discharge end 11 in order that the discharged stream of gas and chemical may be distributed in a fan-shaped blast.

Figure 1 illustrates my method o-f extinguishing res, using the type of apparatus and the type of chemical above described. The iire shown is an oil fire, a pit of oil being represented by the numeral 12. Flames and smoke from the burning oil are represented by the reference numeral 13. In lighting a fire of this type, which, as is well known, is an extremely diiiicult one to extinguish by ordinary means, the operator, indicated by the reference numeral 14, drags the flexible hose 9 with him to the burning pit and directs the nozzle 10 toward the base of the fire, the valves 5 and 6 being adjusted to deliver gas into the container 1 under say about 200 lbs. per sq. in. pressure. A fan-shaped stream of gas under high pressure and at a. high velocity and containing the dry lire extinguishing chemical uniformly mixed and distributed therein, is thus delivered as at 15 directly against the base of the re.

The velocity and volume of the gaseous stream so delivered forms a protective screen to prevent the operator from being scorched or burned and permit him to approach the fire more closely than would otherwise be possible. Also, the rapid iow of gas away from the operator draws with it a flow of cool air from behind the operator that surrounds him and further protects him from the heat of the iire.

The operator 14C starts at one end of the burning oil pit and proceeds rapidly toward the other end of the pit, usually being able to extinguish the re as rapidly as he can run. For instance, I have demonstrated in putting out oil fires in pits as large as 6 x 36 ft. that the fire can be extinguished in less than ten seconds by my method.

It is an important feature of my method that the residues formed by the composition of the dry fire extinguishing chemical form over the burning objects, such as the oil in the instance above described, a thick flux that prevents reignition or flare-back of the oil. This flux forms a continuous protective coating over the surface of the oil and spreads as rapidly as the ame is eX- tinguished so that a Hare-back cannot occur. Because of the heat of the re and perhaps the inclusion of undecomposed chemicals in the residual flux, this flux foams up to form a relatively deep smothering blanket over the heated surface of the oil.

It will be understood that other types of fires may be extinguished by my method, including such extremely diiiicult fires to fight as burning ether, alcohol, pyroxylin lacquer solvents, and the like. Ordinary wood res may likewise be extinguished in a similar manner.

The important feature of my invention is that the gaseous stream containing the dry chemical is delivered under such pressure and at such a high velocity that it forms a protective screen for the operator, thereby enabling him to approach the re much more closely than would otherwise be possible. The very considerable advantages in fighting a fire with a dry chemical rather than with a liquid are obvious, since there is no attendant damage such as results from the use of liquid.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. 'Ihe method of extinguishingiires which 5 comprises directing against'the iire a stream of a gas that doeslnetfsulpport combustion and a finely pqwde: hielnical capable of forming a lire sni'theringgas when heated, the stream of"`gasiig`delivered in such a manner under suchmghgpressure and at such high velocity as to formuaprotective curtain for the operatrwagainlst the heat of the fire, whereby theop'erator can approach the lire much more closffelythanf: would otherwise be possible without himselbing burned.

2. The methodofextinguishing fires which comprises directing against the fire a fanshyapedlstream of mixed gas and dry tim tinguishing chemical under a discharge pressure of above 100 lbs. per sq. in., whereby the velocity of said discharging stream is such as to drive the heat of the re away from the operator and cause an inflow of unheated air around the body of the operator to protect him and enable him to approach the fire more closely.

3. The method of extinguishing fires which comprises directing a continuously uniform gaseous mixture containing a freely flowing fire extinguishing powder against a iire,

the gaseous mixture being delivered in a fanshape stream under such high pressure as to form a curtain to protect the operator against the heat of the re.

4. The method of extinguishing fires which comprises directing against the base of a re a fan-shaped, high pressure stream of a noncombustion supporting gas containing a suspended powdered mixture composed principally of sodium bicarbonate, said mixture forming over the burning surface a Ere smothering flux. t

In testimony whereof I have hereunto subscribed my name at Chicago, Cook County,

Illinois.

LODIAS J. DUGAS.

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