US2385449A - Fire extinguisher - Google Patents

Description

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INVENTR William Koehler BY 7A ATTORNEY Patented Sept. 25, 1945 UNITED STATES PATENT oFFlcE 2,385,449 FIRE EXTINGUTSHER william Koehler, cleveland Heights, ohio Application September 17, 1943, Serial No. 502,782 l claims. (c1. 16a- 31) This invention relates to an improvement in ilre extinguishing media and means to discharge such media from a storage receptacle. More particularly, this invention relates to a glazeforming fire-extinguishing medium and a fire extinguisher which will discharge such a medium under the pressure oi' a. lire-extinguishing gas in such a manner that substantially all of the lire-extinguishing gas will be carried with the discharged medium, thereby obtaining the optimum utilization of the lire-extinguishing gas. My invention is useful in extinguishing substantially all types of combustion supported by the ambient atmosphere and is especially useful in extinguishing high-temperature combustion such as that produced by burning metallic magnesium. This application is a, continuation-impart of my application for a re extinguishing medium, Seriai No. 475,697, filed February 12, 1943.

It is the general practice to smother a fire by a blanketof an incombustible medium in the form of a. gas, liquid, or powder. When the extinguishing medium is applied in such forms, however, the volume of extinguisher required is dependent not only upon the area to be blanketed but also upon the violence of the fire. In order to reduce the` volume of extinguisher required, the extinguisher is often applied in the form of a foam. However, even foams tend to break down and blow away when employed on violent high-temperature fires. of this invention to provide a lire-extinguishing medium which cannot only be applied in the form of a foam but which also forms a hard glaze or varnish upon the burning surfaces when the foam tends to break down under high temperatures.

It is the objecty My fire-extinguishing medium is preferably comprised of a neutralized or alkaline aqueous solution or suspension of an inorganic wetting and glaze-forming agent or agents, such as, for

. example, an aqueous solution of metallic haloids It is also general practise to expel a re-extinguishing liquid from a storage container by means of a nre-extinguishing gas under pressure. A fault of most of such re extinguishers, however, is that a substantial portion of the gas remains in the container until after the liquid-is discharged; thus, a substantial portion of the gas is not utilized as an extinguishing medium but is simply dissipated into the atmosphere. It has `been proposed to so baille the discharge nozzle of a storage container that the expelled liquid and expelling gas will be intermingled into a foam which carries the expelling gas along with the expelled liquid; the increased resistance of such ballles, however, requiredan increase in static pressure of the gas within the storage containers and thus defeated the purpose of the proposals. Accordingly, it is another object of this invention such as calcium chloride and/or magnesium chloride. Other suitable wetting and glazeforming agents may be sodium ammonium phosphate, sodium phosphate, borax, and the like.

As a specific example of my rire-extinguishing liquid, approximately equal parts of calcium chloride and magnesium chloride are dissolved in water until the specific gravity of the solution ranges between 1.2 and 1.5. Calcium hydroxide is then added to the solution until the pH value ranges from 7 to 9. 'I'he solution is then filtered to remove undissolved calcium hydroxide or a1- lowed to stand until the clear solution can be decanted. In commercial practice, residue brines orbitterns may be employed as the source of magnesium chloride and suitable quantities of calcium chloride may be added, if necessary. Care should be taken to dilute the calcium chlo ride and magnesium chloride solutions to a specic gravity ranging between approximately 1.2 and 1.5. If the lower limit is not met, the solution will not have effective strength; if the upper limit is exceeded, crystallization is likely to Occur during storage at low temperatures. Suitable wetting and glaze-forming agents such as those suggested may be employed but in all cases the solutions should be at least neutralized to avoid corrosion of the storage containers employed.

My fire-extinguishing liquid is preferably stored in a container as disclosed in the drawing in which I0 represents a storage container or Vessel provided with a liquid-refill safety plug I2. Threadedly secured in the container Ill is the tting I4 having the discharge passage i6 leading from the interior of the container I0 to the exterior of the iltting I4. At the exterior port of the passage IB a discharge nozzle I8 is threadedly secured: the

nozzle it may be replaced by the conventional exible hose and nozzle if desired.

A vertical Well-tube Bil is fixed in the iitting i@ at the interior port of the discharge passage, the Well-tube extending from the fitting ifi nearly to the bottom oi the container it. A small relief vent 2i is drilled through the tube 2@ adjacent the discharge passage. Within the Well-tube 2d and concentric therewith is a gas tube 22 carried at one end by the fitting ifi, the other end of the gas tube 22 terminating just above the bottom of the container it. The gas tube 22 is connected to a gas storage cylinder 2d by gas passages 2d in the tting lil. ln the embodiment disclosed the gas cylinder 2d is carried by the fitting Within the container iii to protect the cylinder trom rough handling. The gas passages between the cylinder 28 and tube 22 are closable by the normally open plug 2l and the normally closed needle valve ii. spur passage entering between the plug 2l and the gas cylinder 2d is normally closed by the refill plug 29.

The operation oi' my tire-extinguisher is as follows: With the container l@ nlied `with my lre= extinguishing liquid as described above and with a nre-extinguishing gas, i. e., carbon dioxide, sui-a phur dioxide, ammonia, nitrogen, chlorine, or the like, under pressure in the gas cylinder 22d, the normally closed discharge valve 2d is opened as shown. in the drawing. Gas is discharged through the passages 2t and gas tube 22 to the bottom of the container iu, where the gas breaks into hubbles and rises in the well=tube 2li. in order to decrease the size of the bubbles, the open end of the gas tube 22 may be serrated, as shown. es the gas rises in the Welbtube 2t, nre-extinguishing liquid is carried with the gos. Due to the disn solved wetting agents in the fire-extinguishing liduid, the surta/ce tension of the liquid is reduced and froth or roani commences to be produced in the vvelltube 2d. Due to the absence of bales and a minimum of restriction in the discharge passage i ii and nozzle i8, the'gas continues to emand as it rises in the Welltube, thus accelerating the entrained 'oarn. Probably because the acceleration of the i'oam is due primarily to the expansion of the expelling gas, there is apparently comparatively little back or static pressure in the container id. in order to maintain Within the conn tainer a pressure which is at least above atmospheric, the small relief vent 2i in the tube bleeds some pressure from the Well=tube to allow the liquid to fall in the container iii; also, if the supply of liquid is not exhausted in the me or" the extinguisher, the gas cylinder is closed by the valve 2d and such back pressure as may exist can bleed baci; into the well-tube Without further discharge of liquid. The vent 'il also serves the function of allowing air retained in the container to expand and contract during storage without discharging the liquid.

As the foam ci' liquid and expelling gas leave the nozzle id, gas dissolved or absorbed in the lispuid during the travel up the well-tube and through the discharge passage will be released, further breaking up the liquid into a gas-liquid emulsion. The discharged stream of gas-liquid emulsion hits the burning surf aces as a Wet, sticky foam which breaks down rather quickly, releasing the smothering gas and wetting the surfaces with the fire-extinguishing liquid. If the temperature of the fire is such that it evaporates the water quickly, thus overcoming the wetting action of the liquid, the dissolved agents are precipitated on the wetted surfaces as une powders assenso which quickly fuse into a hard, incombustibie glaze or varnish which will withstand extremely high temperatures and which will prevent the surfaces from being reignited by sparks, for example.

From the foregoing it should be apparent that my fire-extinguishing liquid is particularly useul in extinguishing high-temperature fires, such as burning magnesium. Normally water and aqueous solutions should be avoided in extinguishing magnesium nres, but my aqueous solution may be used successfully because of the residual glaze produced and because the solution is applied as a foam, thus avoiding the steam explosions which result when streams of liquid are employed.

It should also be apparent that my container may be readily recharged. The container i@ is refilled through the plug i2. To recharge the ses .cylinder i2, the plug 2l' is closed, the plug 29 is removed, and the tting id is connected to suitable reservoir of compressed, i. e., liquiiied, gas. The valve 2&3 is then opened and the cylinder 2d is recharged. When recharging is complete, the valve 2b is reclosed, the plug 29 is rei placed, and the plug iii reopened. In someinstances it may be more convenient to recharge the container with gas by substituting the cylinder 2d with a new sealed gas cylinder. In auch instances either the needle valve stem of the valve 28 or the socket for the gas cylinder should be provided with a suitable seal-puncturing )broa iection. It is also to be understood that in certain embodiments the disclosed manual valve may be replaced with a suitable temperaturerem sponsive automatic valve.

From the foregoing, it is apparent that invention is not limited tothe specific and preferred embodiments disclosed but may be medim ned, either in whole or in part, within the scope of the appended claims.

What is claimed is:

i. A storage container for a firextinguisldng medium comprising a container having a dis charge passage, an open-.ended well-tube extendu ing from said discharge passageto a point adjacent the bottom of said container, a rst means for introducing gas into said well-tube adjacent the 'open end thereof, a reservoir for containing gas under pressure, a second means connecting said reservoir to said first means, and a valve in said second means for controlling the flow of gas from said reservoir to said rst means.

2. A storage container as dened in claim i in which said well-tube is vented to the interior or' said container adjacent said discharge passage.

3. in a storage container fer a foamable fireextinguishing liquid, a foam-forming discharge mechanism comprising a vertical open-ended Wellgtube within said container connected to a discharge passage in said container, theoncn end of said Well-,tube extending below the normal level o liquid in said container, a gas tube having an outlet into said well tube adjacent the open end thereof,-a reservoir for storing gas under pressure,` means having a gas passage for connecting said gas tube to said reservoir, and a valve for controlling the iiovv oi said gas from said reservoir into said well-tube.

fi. ln a container as deiined in claim 3, gas reservoir recharging means comprising a means for closing said gas passage between said valve and said gas tube, and a recharging plug normally closing a spur passage connected to said gas passage between said closing means and said valve.

5. In a device for storinz a foamable iire-extinguishing liquid and i'ozl discharging such liquid as a foam, said device comprising a liquid container having a discharge opening, a gas reservoir, and a valve for controlling the ilow of gas 5 from said reservoir, a liquid discharging and foaming means comprising a vertically extending tube connected to the discharge opening and having a vent adjacent said opening, said tube having an open end below the normal level oi 10 WILLIAM KOERIER.

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