US2008847A - Method of extinguishing fires - Google Patents

Description

July 23, 1935.

5. F. BARCLAY METHOD OF EXTINGUISHING FIRES Filed April 8, 1932 ZNVENI'QR.

SIDNEY FRASER BARCLAY ATTOlZ/VE 1.

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Patented. July 23, 1935 UNlTED STATES PATENT OFFICE 2t00834'l METHOD OF EXTIN'G'IUI.SHIN?!.FIRES- Sidney Barclay, Park Works, Manchester, England, assignor to General Fire erj Company, Providence, B.

ware- L, a corporation of Application April 8, 1932, Serial No. 604,125

In Great Britain April 10, 1931 comm. '(cl. 169-4) 10 drench the material in the area. In the case of inflammable'liquids such, for example, as petrol .and fuel oil, it is foundthat the ordinary sprinkler installation is not effective in case of fire due to the rapidity and fierceness of the conflagration, but a certain measure of success is obtainable with inflammable liquids low down in deep tanks where quiet conditions exist above the inflammable liquid if the water can efi'ectively prevent the up'fiow of the burnt gases and the downflow of air.

guishing fires ofinfiammable liquids immiscible with water, in which water is projected on to or into the liquid so as to produce therewithat the liquid surface an emulsion which will not In the art of emulsification, ble liquids which are immiscible with water are commonly classedas oils, whether of vegetable, min- 30 eralror animal origin. Such an oil and water form'a non-inflammable emulsion when the two are agitated together. The oils of commerce do not ordinarily contain emulsifyingfagents, and 'under such circumstances in the emulsions formed the oil is inthe dispersed phase, that is scattered as" minute isolated droplets throughout the continuous or water phase. Emulsions of this type have heretofore been of little or no commercial 'value because of lack of permanence, but this 40 practice of my invention because permanence of the emulsion is not of primary importance. If substantially the entire surface of the inflammable liquid is emulsified, that is, if the droplets of oil at the" surface are surrounded by water, the emulsion is non-combustible and the fire will be extinguished. Such a non-inflammable emulsion need exist only during the agitation of the liquid This emulsion may be formed by bombarding the surface of the burning liquidf-witb water from above, or the water may be'forcibly introduced to the liquid below its surface to efiect the formation of the emulsion at the surface.

My invention consists in' a method of extincharacteristic is not a deterrent to the successful flammable liquid in such For the purposes in view, namely the extinguishing of fires, the emulsion need only be provided at the surface of the liquid, and because of this,- the fire can be put out with a relatively small quantity of water.

My invention further consists in the use of means for facilitating the emulsiflcation by water of the surface of the i 1 le liq'uidwhen fire occurs. That is, an emulsifying agent may be added to the water which will facilitate the emulsifying action and insure the formation of 10 the desired non-inflammable emulsion. Should there be any question as to the type of emulsion likely to be formed by projecting water into contact with any particular oil, one of the methods of identification common to the art. may be em-- ployed. I prefer the electrical conductivity method in which two electrodes are immersed at about 1 to $4 apart in the emulsion. A current of from 12 to 50 volts is sent through the elfitrodes and the current flow measured by a eter. If the reading approximates that obtainedwhen the electrodes are immersed-in water, then the emulsion contains oil in the dispersed phase, whereas should the reading be'much lower than when'the electrodes are'immersed 5 in water, it indicates that the oil lain-the dispersing phase. This method is advantageous be cause it may be employed during agitation, which is necessary in cases where the emulsionisformed without an emulsifying agent and is very fleeting.

Apparatus by which my improved method may be practiced is shown in the accompanying drawing but it is merely illustrative and it is intended that the patent shall'cover by suitable expression inthe appended claims whatever features of patentable novelty exist in the invention disclosed.

' In the drawing:

- Figure 1 is a plan of a tank containing an infiammable liquid with mea'ns'associated there- 40 withforproviding at thesurface of such liquid an emulsion of that liquid and water;

Figure 2 is a vertical section, taken'as on line 2-4 of 1;

.Figure 3 is an elevation of a nozzle adapted .to project thewater onto the surface of the inmanner as to f rm the desired emulsion; and

- vFigure 4Lis a section taken as on line 4-4 of Figure 3.

' In one convenient'application of my inventiont'o a tank I containing an imflammable liquid2, such as petrol foreirample, I mount sprayer" nomles 3 above the surface of the liquid, the

headsbeing spaced, say about four feet apart. As here shown for illustration, the nozzles 3 are mounted on pipes 4 carried by a frame 5 that is supported on floats 6 above the surface of the liquid. The pipes 4 are each connected to a vertical pipe I to which a non-inflammable fluid is conducted by a pipe 8 suitably connected to both the pipe I and a fixed pipe 9 to permit the frame 5 and its associated parts to rise and fallwith changes in the level of the liquid in the tank.

A sprayer nozzle 3, shown in Figures 3- and 4, preferably has a converging throat l0 leading to a discharge opening I! of about inchin diameter. The water issues from the opening l2 as a vertical jet and strikes a deflector l4 mounted on the arm l6 above the opening. This deflector is about 1 inches from the opening and is preferably circular in shape having an abruptly.

turned down edge or flange Ha. which may be serrated if desired. The effect of the deflector is to deflect the water in finely divided jets downward on to the surface of the inflammable liquid in such manner as to form a non-inflammable emulsion therewith.

Connected to the bottom of pipe I are other horizontal pipes l8 so arranged as to be submerged in the liquid. These pipes are provided with a multiplicity of discharge openings 20 from which the water may be discharged into contact with the inflammable liquid to form an emulsion. Hand valves 22 and 2 can be set so that either the sprayer nozzles 3, or the pipes l8, or both, may be employed for discharge of the water. The supply for pipe 9 may behand controlled or automatically controlled as desired.

It will be appreciated that the more highly inflammable the liquid, the greateris the degree of emulsiflcation necessary to reduce it to a condition in which it will not burn. This can be controlled by varying the water pressure and by the useof means for facilitating the emulsiflcation. While no exact rule regarding the relation between pressure and inflammability is known, I

have found that generally the water pressure needed bears aninverse ratio to the flash point of the inflammable liquid. For example, transformer oil which flashes at about 350 F. may' be readily emulsified with a water pressure as low as 30 pounds, while .with gasoline which flashes at about F., the pressure should be about pounds. As a; practical guide it may be said that with oils having flashpoints. below 0 F. the water pressure may be 80 pounds or more, with oils flashing between 0 F. and 200 F. the water pressure need be only 50 pounds or more, and with oils which flash above 200 F., 30 pounds or more ofwater pressure will suflice; In cases of uncertaintyfall doubt" can very easily be 'r moved. by a simple test. A smallshallow pan if one or two square feet in area may bexset beneath a sprayer a distance corresponding to that in the contemplated installation. The oil in question'may then be placed in the pan and ignited. The emulsifying effect of water discharged from the sprayer under varying pressures can then be determinedand a proper pressure selected for the actual installation.

' In the case of fuel oil, I flnd that the emulsification can be satisfactorily produced by water sprayers immersed in the oil, such as the discharge pipes 18, near the surface .so as to .produce the non-ble emulsion at the surface. vFor fuel oil, .the water pressure employed may be from 30 lbs. ,per square inch upwards.

- The sprayer heads of particular tank of adapted to be brought into operation automati cally. They may, for example, be under the con- 1 trol of one or more pilot automatic sprinklers 20 of ordinary type, that is to say, when the latter are brought into operation by flre, the sprayer heads are automatically supplied with water by means of, for example, a flooding valve 20 of known form opened consequent upon the fall in pressure in the water supply pipe II to the sprinklers. As an alternative the supply of water to the sprayers may be under hand control, in which case a manually operable valve 32 in another line 9' connected to pipe 9 would be employed. Both forms of supply control are herein illustrated. Y

I may vary the details of the sprayer, the distributing plates and of the control devices to meet any particular requirements. V

I may add any suitable emulsifying agent such as gum arabic to the water although as previous- 1y described herein water without such-additions may be suitable for my purpose.

It will be noted that my invention does not rely upon the cooling effect of the water or upon the exclusion of air from the liquid surface by the water for its results, which as already explained are due to the emulsiflcation of the liquid by the water and the fact that such emulsions have higher ignition temperaturesthan the inflammable liquids from which they are made according to the degree of the emulsiflcation, until a point is reached at which the emulsion will not burn.

What I claim is: 7

l. A method of extinguishing a burning inflammable liquid immiscible with .water and cspable of forming therewith a liquid-in-water emulsion, which comprises bombarding substantially the entire surface of the liquid with flnely divided water in such a manner as to form a noninflammable emulsion.

2. A method of extinguishing a burning inflammable liquid imm'iscible'w-ith water and copable" of forming therewith a liquid-"in water emulsion, which comprises forcibly spraying substantially the entire surface of said liquid with.

flammable liquid immiscible with water. and cnpable of forming therewithfa liquid-in-ister emulsion, in which a water sprayer system b used, characterized in this, that the sprayer jets effect such a concentrated bombardment of the whole of the burning surface liquid that "such -surface liquid is broken up-and emulsified to non-inflammable aqueous emulsion.

5. A method of extinguishlnk is burning inflammable liquid immiscible with mland onpable of forming therewith a liquid-inmate! emulsion, which. consists in providing a device capableoi' discharging water as a spray let. and discharging water from said device into cili-- tact with substantially the entire $111800 0! ill liquid in such m'anner astobreatup the liquid 1 and term therewith an emlflsion in which the liquidis'inthedispersedphase.

8. Amethod of e a burning inflammable liquid immiscible with water and ea.- 5 iable of forming therewith a liquid-in-water emlflsion, which comprises bombarding tiaiiy the'entire mm o! the-liquid with finely divided water containing an emulsifying agent capable of facilitating eeidiiquid-in -water emulsmnJnsuehmanneraiitoIormthesaidemuI- 8101!.

SIDNEY BARCLAY.

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