US2645292A - Apparatus for extinguishing fires - Google Patents

Description

y 4, 1953 Y E. c. WILLIAMS APPARATUS FOR EXTINGUISHING FIRES 2 Sh'ets-Sheet 1 Filed April 16, 1951 INVENTOR. EVAN C mLL/AMS A TTORNEVS.

y 1953 a. c. WILLIAMS 2,645,292

' APPARATUS FOR EXTINGUISHING FIRES Filed April 16, 1951 2 Sheets-Sheet 2 EVAN QW/LL/AMS ATTORNEYS.

IINVENTOR.

' patented July 14,1953

UNI ED] STATES PATENT OFFICE 1 i 2,645,292 r API fARATUSFOREXTINGUISHING macs Evan Clifl'ordWilliams, Wilton, Conn; assignor to General Aniline &*' Film Corporation, New YorkyN. Y., a corporation of Delaware Application April 1 1951i,SerialNo. 221,231

The present invention relates to an apparatus for extinguishing fires and more particularly to' an apparatus for mechanically generating foam to be applied in extinguishingfires.

The foams produced by known fire extinguishing devices have certain serious limitations when used to extinguish flammable liquid fires,jsuch as gasoline and benzene fires, and other fires since the foam is, in practice, projected onto the fire in the form of a compact stream. Such a stream of foam offers little personnel protectiomso the fireman must stand at a c'onsiderable distance from the fire because of theheatj This requires that the foam-forming solution be under high pressure in order that the solid stream will have sufficient throw to reach the fire. ,Also, to be most effective the stream must be directed at a solid, vertical backstop near the burning liquid so that the foam will spatter and flow gently over the surface. If the foam stream hits the burning liquid surface directly, it agitates'the fire and blows the foam blanket away 'or even forces the burning liquid to the top of the surrounding foam and scatters the fire. In fires where no backstops are available, such as spill or'airplane crash fires,

the foam stream cannot be effectively used to ex tinguish the resulting liquid fire.

The present invention provides an apparatus for generating fire extinguishing foam based on an entirely new principle. The foam produced is extraordinarily effective for extinguishing flammable liquid and other fires when applied thereto; The foam is obtained in the form of a large body 'or cloud having considerable vertical thickness and lateral spread and made up of relatively uni-. form, discrete bubbles in a continuous air phase. The foam produced by the presentinvention can 2Claims. (01. 169-15)] best be described as ,beingin the, nature ofa spray or fog of discrete bubbles, and is, accordingly, referred to herein: as fog foam.

The fog foam produced by the apparatus of the instant invention has been found to extinguish with great rapidity fires which foam produced by known devices fails to extinguish. Unlike the solid or compact streams of foam heretofore applied to fires, fog foam provides excellent personnel protection, permitting the fireman to approach the fire closely, since the present invention provides a large body or cloud of foam having considerable vertical thicknessand lateral coverage, which serves as a heat shielding screen for the fireman,- The fog foam ma be directly in extinguishing crash and spill fires. The fog foam'falls gently on the surface of the burning liquid without agitating it, andcovers the burn- 7 ing liquid quickly with a'blanket of foam that rapidly extinguishes the fire.

Other advantag'esof thepresent invention are that itprovidesafiner bubble foam, and that it produces excellent foams from solutions that are poorin foaming properties and are not readily converted into foam by devices heretcfore used for preparingfoams. V

It-is, therefore, among the objects of the present invention to provide a simplified apparatus for producing fire extinguishing foam .and,extin-- guishing fires, which invention results in the aforementioned advantages. f

In accordance with the instant invention the novel apparatus for producing the fog foam comprises a means, such as a jet or nozzle, for discharging the foam-forming solution as a fog, and a foraminous member, suchas a screen or perforatedplate upon' which'the particles impinge, placed at a predetermined distance from the nozzle. g

' In other words, theinvention comprises broad- 1y a fog-producing nozzzlesuch as the'one illustrated in the drawings and a screen placed in front of it.

For a'given foam-forming solution, given type of nozzle, given pressure, given rate of flow of the solution, and given aperture size in the foraminou sj member, a relatively definite distance between the end of the nozzle and the foraminous member is r'equiredto produce the desired foam with sufiicient throw and spread to blanket the fire. 1 For a different foam-forming solution, type ofnozzle, pressure, rate of flow of the solution,

from the nozzle to produce the foam fog with sufficicnt forward throw to reach the fire.

It has been observed that little if any mm is produced when the screen is set too far away from the nozzle, and itappears as though the particles of foam-forming solution impinging. thereon bounce back from the screen rather than pass therethrough. On the other hand, if the screen isplaced too near the nozzle, the particles pass throughthefscreen with only poor conversion into foam. Inpractice,"the optimum position is readily determinedby manually adjusting the 3 7 screen to the position where maximum foam and throw of the foam are obtained. Once this posi- 7 tion has been found for any particular type solution, nozzle, pressure, and rate of flow of liquid through the nozzle, theiscreen can be fixed in that position. In general, the size of the bubbles in the fog foam increases with the size of the apertures in the foraminous material or the size of mesh in the screen, while the smaller the mesh the smaller the bubbles.

It will be understood that this differentiates from the garden hose nozzle with a screen placed in front of it known to the prior art. The garden hose nozzle is not capable of forming a fog, and whereas a screen will cause. theformation of V tinguishing spill and crash fires where no backpermitting the fireman closely to approach the finer particles using'the, garden hosenozzle, a

screen in front of a fog nozzle causes agg1omera-' tion or larger particle formation with plain water.

Fig. 4 is in part a cross-section of a third modification. V a a Fig. 5 is an end view of the device of Fig. 4.

Fig. 61s a longitudinal View of a fourth modification. V

Fig. 7 is a longitudinal view partially in crosssection of a fifth modification.

Fig. 8 is an end view thereof.

Fig. 9 is a longitudinal view partially in crosssection of a sixth modification.

Fig. 10 is a longitudinal view partially in crosssection of a seventh modification.

In'the embodiment of the invention as illus trated in Figs/1 and 2, the apparatus comprises a nozzle I which may be suitably attached'inany V manner as by means of threading to a pipe or hose 2 which feeds a suitably supply of a foamforming liquid under pressure to the nozzle from any convenient source.

The nozzle is provided with a spiral shaped bafile 3 which imparts to the liquid flowing through the nozzle a rotating motion as it leaves the orifice 4 and assists in the breaking up of the liquid intodroplets or particles 5. The particles impinge upon and pass through a screen 6 removably mounted in a channeled U-shaped frame 1. Frame 1 is suitably attached as by welding or other fastening means to a'rod 8, which is slidably mounted through openings 9 in posts III which may be attached as by welding to pipe 2. Posts ID are provided with set screws II. By moving rod 8, the screen may be set at any predetermined distance from nozzle I and fixed in this position by set screws II. For example, the screen may be set at either of the positions shown by the full lines, or by the dotted lines in Fig. 1. V

In the operation of this embodiment of the in- V 'vention, any "suitable foam-forming solution, such as an aqueous solution of saponine or degraded proteins as, for example, degraded soy bean meal, is supplied under pressure to the'nozzle'I through conduit 2. The baffle means 3 rotates the solution so that as it leaves orifice 4, it is brokenup into fine particles or droplets 5. The screen 6 is manually adjusted and set board or backstop is available.

Although the fog foam produced by the present inventionprovides excellent personnel protection,

fire, thereby. reducing the throw required, where it may be desirable to produce a longer throw j of the fog foam, the rod 8 may be in the form of a tube I3 as shown in Fig. 3 through which a gas a under pressure. such as air, carbon dioxide-or nitrogen, may be forced and discharged through a nozzle III mounted at the end of a tube and extending slightly beyond and beneath the screen 6. The nozzle may be fan-shaped so as to deliver the gas over a'considerable area. The gas issu ing from the nozzle I4 picks up the foam after it has formed and imparts to it.a longer throw. When non-combustion supporting gases, such as nitrogen or carbon dioxide, are used, not only is additional throw imparted to the fog foam, but the fire extinguishing properties thereof are improved due to the action of the gas.

In the embodiment shown in Figs. 4 and 5, there is threaded to nozzle I a disc I5, such as, for example, a spider wheel, having openings I6 and I! for the'admission of air. The periphery of the wheel is provided with threads I8. Threaded on the wheel and rotatable theron is a collar I9 having mounted therein one or more foraminous discs, such as wire mesh screens 20, which may be separated byand held in place by retaining rings 2| and flange 22.

In operation, screens20 are set as the proper distance from nozzle I by rotating collar I9. Depending on the direction of the rotation, the screens may be moved toward or away from the nozzle. When the screens are set at the proper distance, the particles of liquid from the nozzle I impinge upon the screens and pass therethrough forming a fog foam. The collar is of such diameter that it does not confine the particles of liquid; The. use of two or more screens permits the utilization of coarser mesh screening the combination produces as finebubbles as is obtained by using a. single finer mesh screen. It

is to be understood, however, thatonly a single screen may be used, if desired.

In the embodiment of the invention shown in Fig. 6, there are a'plurality of nozzles Ia, similar in structure to nozzle I shown in Fig. 1, mounted in a header 2a which may be threadedto a coupling 2b which in turn is threaded to foam-forming solution supply pipe 2. Adjustably mounted on the corrugated-shaped portion 20 of the coupling is a cylindrical shaped screen 23. One end 24 of the screen 'is secured, as by welding, to a clamp 25 which surrounds portion 20 of the coupler and is provided with a fastening means, such as a bolt andnut'combination 2B. "The other end of the cylinder comprises a disc-shaped screen distance 'from nozzles Ia, by sliding clamp 25 into any one of the grooves of the corrugated portio 2c and tightening the clamp =thereabout. In the operation of this device, the fine particles of foam-forming solution'discharged by the nozzles la impinge upon the screen 21 and on passing therethrough form a foam. Proper ad justment of the distance of screen 21 from nozzles la is readily obtained by moving the clamping member 25 to various positions on the coupler 2c and fastening it. at that position which gives maximum fog foam and throw. The clamp 25. once tightened, is prevented from slipping by the groove portions of the corrugations.

In the modifications shown in Figs. '7 and 8, there is threaded onto the nozzle 1 a collar or coupling 28. The collar is provided with arcshaped prongs 29 to which are secured a cylindrical screen element 30 having formed integrally therewith a disc-shaped screen 3! The distance of the screen 3| from the nozzle I is adjusted by rotation of thecollar 28. Impingement of the particles of the foam-forming liquid discharged from the nozzle upon screen 3| and their passage therethrough results in the formation of a fog foam, highly effective for extinguishing fires.

In the modification shown in Fig. 9, the screen 32 is in the form of a cone. The base of the cone is attached to a disc 33 having openings 34 as, for example, a spider wheel such as is shown in Fig. 4. The disc 33 is threaded to the nozzle I and may be rotated thereon so as to adjust the distance of the screen 32 from the nozzle. After the screen 32 is adjusted to the proper position by rotation of disc 33 the particles of foamforming liquid issuing from the nozzle will impinge upon the apex portion of the cone-shaped screen and on passing therethrough will result in a fog foam having considerable throw.

In the modification shown in Fig. 10, the structure is similar to the device shown in Figs. 4 and 5. However, threaded to the collar I9 is a tube 35 for projecting, where it is desired, a more or less confined stream of fog foam. To increase the throw of the foam, there is provided a conduit 36 which has a nozzle 37 entering the tube adjacent the screen 20. The conduit is connected to a supply of a gas, such as air, carbon dioxide, nitrogen, etc., under pressure.

In operation the screen 20 is adjusted to the proper distance from the nozzle l by rotation of collar l9 on the threaded portion of the nozzle. As the particles of foam-forming liquid impinge upon the screen and pass therethrough, a fog foam is formed which is confined by tube 35. Increase in throw of the foam is provided by forcing a gas under pressure through the tube 36 and nozzle 31. The fog foam issues from the tube 35 in a more or less compact stream made up of discrete and highly uniform bubbles.

A highly desirable advantage of the modification, as illustrated in Fig. 10, is that it provides an apparatus that may be used interchangeably to produce either a stream of foam when assembled as shown, a fog foam by removing tube 35, or a spray of fine particles or droplets of liquid by removing collar 19 with its screen 20.

Instead of a single screen upon which the particles of foam-forming liquid may be impinged, there may be utilized with any of the embodiments herein described two or more screens placed face to face as pointed out hereinbefore. Use of plurality of screens results in a finer foam even when coarser mesh screens are used. The mesh of the screens may be of the same size or may be of different sizes. In the latter case, the

screen withv the larger mesh is preferabl-y placed adjacent the nozzle. 1

Instead of the specific nozzle, shown, there may be used any other suitablenozzle which "forms droplets or particles since formation ofqthe foam is independent ofthe particular nozzle by. which the droplets or particles are formed to impinge upon the screen. If desired, a plurality of nozzles may housed in any of the otherembodiments, as shown in Fig. 6, instead of a single nozzle. By such an arrangement, the amount of foam produced'is considerably increased.

Rod 8, tube I 3, and collar l9 may be provided with suitable indicia which indicate when the screen is at the proper predetermined distance from the nozzle with respect to type of foamforming liquid used, pressure and flow ofthe liquid in the nozzle, and mesh size of the screen.

In general, the mesh size of the screen may be varied within wide limits. For example, screens varying from approximately 4 to 30 mesh per square inch have been found highly satisfactory. Instead of a wire mesh screen, there may be used any foraminous material, such as a screen made from sheet material having holes or openings punched therein.

It is to be understood that instead of fastening the frame 1 to the rod 8 or tube l3 and providing adjustment of the distance of the screen from the nozzle by moving the rod, the rod may be fixed and the frame may be slidably mounted on the rod and set at any selected position by any suitable setting means, such as thumb screws.

Where merely a spray of foam-forming liquid is desired to be applied to the fire, the screens may be readily removed from their holders or in the case of the devices shown in Figs. 4 to 10, the whole assembly including the screen may be removed from th nozzle. In such case, there is obtained a spray of fine particles or droplets which are directed towards the fire in the usual manner.

It is to be understood that the above illustrations are merely by way of example and not by way of limitation, and that any changes or modifications which come within the scope of the invention may be made without departing from the spirit thereof.

This application is a continuation-in-part of my copending application Serial No. 593,871, filed may 15, 1945, now abandoned.

I claim:

1. A fire extinguishing apparatus for producing fire extinguishing fog foam which comprises a jet designed to convert foam-forming liquid into fog, a screen spaced from and in front of said jet, and a nozzle secured just in front of said screen and substantially parallel to said jet for applying a gas under pressure to increase the flow of fog foam in a forward direction.

2. A fire extinguishing apparatus for producing fire extinguishing fog foam which comprises a jet designed to convert foam-forming liquid into fog. a spiral baille spaced behind and substantially concentric with said J'et, a screen spaced from and in front of said jet and a nozzle secured just in front of said screen and substantially parallel t0 Said l t r pplyi a gas under pressure to increase the flow of fog foam in a forward direction.

EVAN CLIFFORD WILLIAMS.

(References on following page) j References'cited in the file of "this'patent Number V UNITED STATES PATENTS Number Name V Date 3 21 654,132 Bush July 24,1900 5 1,457,895 campanella June 5, .1923 1,916,912 Armstrong July 4, .1 3 Number 2,043,599 Waldschmidt June 9, 1936 1 005 2,164,153 'Friedrich June 2'7, 1939 106,934 2,210,846 .Aghnides, 1 ,Aug. 6,1940 10 Name Date Urquhart May 15, 1945 ,Boyd etal Aug. 16, 1949 :F'reeman et a1 Dec. 20, 1949 FOREIGN PATENTS Country Date GreatBritain A. D. 1913 Sweden -1 Mar. 23, 1943

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