Apparatus for producing fire foam

July 15, 1941. c. _K swift etal 2,249,095

APPARATUS FOR PRODUCING FIRE FOAM

Filed April 14, 1939

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Patented July 15, 1941

2,249,095 io

UNITED STATES PATENT OFFICE

2,249,6.5 apparatus for producing fire foam drews &amp; Forbes Company, Camden, N. J·, » corporation of New Jersey

Application April 14, 1939, Serial No. 267,886 (Cl. 261—83) ing foam of the character described which apparatus is comparatively compact and portable^ a capable of delivering the foam to a hose un svstem of pipes under pressure sufficient to con vey said foam, or project the same from a hose nozzle for substantial distances. ,.

ⁿ°A further object of the invention is to provide tion involved therein are hereinafter ^ίυ11^ . forth and shown in the accompanying drawing m ^W Figure 1 is a view in elevation partially in section of one form of apparatus contemplated by 20 the present invention for carrying out the method ^thFfeme 2 is a view in section taken on line ²-Hguro^U3^eis^:a^a^eW similar to Figure 1 illustrating another form of apparatus for P^rod®° ing fire extinguishing foam m accordance with ^thRef¹erri¹ng°now more particularly to Figure 1 of tie Xing the apparatus there illustrated comprises a base or supporting structureJ <j>n which is mounted a support 2 for ^a water supply tank or reservoir 3, a standard ^{4 f}°^ra device designated generally as 5 to feetag a dry foam producing composition, and a notary ₃₈ pump or compressor designated generally as .

³⁵ The rotary pump or compressor 6 is οί: the so-called water-ring type ^(sdC£_n ΐ type) and comprises a rotor I “ which revolve freely within an ehptical casing

An 9 in hydraulic balance. The casing 9 is pr ⁴³ with the requisite main inlet and discharge ports 10 and 11 respectively, and additional inlet ports 12 aid | J: respectively, open to the rotor chamber from the casing while outlet ports I4 and pxhaust from said rotor chamber to the casing «sol»® port 11.. megS»; cally, and as shown in the drawing, the chamber of this compressor has longitudinally elongat end portions and a relatively contracted midportion defined by the continuous inner walls of the chamber, and in this mid-portion is located a power-driven rotor having substantially radial blades, the ends of which are curved in the direction of rotor rotation. The blades of the roto describe a circle substantially tangent to the

Claims. (

This invention relates to new and useful imρϋ ta ««Λ. lor Ο» fire extinguishing foam of the mechanical or air foam type. More particularly the invention relates to a new and improved apparatus for producing a mechanical or air fire extinguishing foam from dry foam producing substances or ^StSr^eto the present invention the production of mechanical or air fire extinguishing foams for ?he most part involved the use of foam producing substances or stabilizers in aqueous or other solution. This practice involves certain relatively serious restrictions in the production and use of the foam due to the necessarily large bul and weight of the material required to be transported and due, also, to the relatively high cost of containers and the like for such materials. Furthermore, a particularly serious.limitation and objection to the use of foam producing sub stances or stabilizers in solution is their susceptibility to freezing. In addition, fire extinguish ing foams Of the type generated by chemical means are subject to breakdown after relative y short time, and caniiot be conveyed by means of hose or pipes to remote points without serious loss of volume and quality. .

With the foregoing observations in mmd, principal object of the present invention is to provide a novel apparatus wherein a dry foam producing agent or stabilizer is continuously proportioned and mixed with water and a suitable gas, and then agitated to produce a fire extinguishing foam of superior 1^· „

Another object of the invention is to provide a novel apparatus for producing a fire extinguishing foam which is highly stable in the presence, of fire and which will not break down for comparatively long periods of time and which may.be conveyed to points substantially remote fromi the point of generation without detrimental effect t its structure or volume. .

Another object of the invention is to provide a novel apparatus for producing fire extinguishing air foam from a dry foam producing composition which normally is not readily soluble in ^W Another object of the invention is to provide a novel method of producing a fire extin^nshrng foam which is not only effective against gasoline and other petroleum product fires, but which is also highly effective against burning alcohol and similar extra hazardous combustible liquids.

Still another object of the invention is to proVide an apparatus for producing fire extinguish- 55

2,248,080 chamber walls at the contracted mid-portion of said chamber and the contour of said walls defines a correspondingly shaped path of movement under the impetus of the rotor blades thus affording the violent agitation essential to pro- 5 duction of a satisfactory and stable fire extinguishing foam.

In the drawing, the discharge port 11 of the pump 6 has connected thereto a hose or the like 16 having a nozzle 17 at its outer end, but in 10 lieu of said hose and nozzle it will be obvious that said pump discharge port fl may have a pipe or system of pipes (not shown) connected thereto by means of which the foam discharged from the pump 6 may be conveyed to one or more rela- 15 tively remote points.

Connected to the main inlet port 10 of the rotary pump 6 is one end of a feed or supply pipe i8, the other end of which is connected to the lower end of a pipe or tube 19 secured axially 20 and vertically within a tank or vessel 20. The tube or pipe 19 is provided with a plurality of apertures 21 therein which extend upward to a point above the tank or vessel 20 where its walls diverge outwardly to form a funnel-shaped inlet 2s 22 for air or other gaseous medium and the dry foam producing composition.

This foam producing composition is fed into the funnel-shaped inlet 22 and pipe or tube 19 by means of the· feeding device 5 mounted upon the 30 standard 4. The feeding device 5 comprises a hopper 23 for the dry foam composition and at the lower end or bottom of this hopper 23 is a table or disk 24 secured on a rotatably mounted vertical shaft 25. The shaft 25 extends an appre- 35 ciable distance upwardly within the hopper 23 and fingers 25α are secured thereon above the table or disk 24 so as to rotate with said shaft 25 and maintain and keep the dry foam composition relatively loose and free to insure proper 40 feed thereof.

• Rotation of the feed table or disk 24 may be accomplished in any suitable manner, for example, as shown, in the drawing by providing gear teeth 26 on the underside thereof for engagement 45 by the teeth of h spur gear 27 which may be driven from a motor 28 either directly or through a belt and pulley system 29 as shown. Discharge or feed of the dry foam composition is effected by revolving or rotating the table or disk 24 to 50 move the material thereon past a feed knife or the like 30 which deflects or directs said material through the discharge opening 31 from which it falls or drops into the upper funnelshaped end 22 of the tube or pipe 19. As shown 55 in Figure 2 of the drawing, the feed knife 30 is adjustable about its pivot 32 to control the width of the discharge opening 31 and thereby control the rate of feed or discharge of the foam agent or stabilizer. 00 _yWater for mixture with the air and dry foam producing composition is supplied to the tank or vessel 20 through a pipe 33 which leads from the bottom of the reservoir . 3 and is connected to said tank 20 adjacent its lower end/said pipe 05 33 being provided with a valve 34 for controlling the passage of water therethrough to the said tank 20. Water is .supplied to the reservoir 3 through a pipe 35 under the control of a valve 36 operated by a float 37 whereby the water in 70 said reservoir 3 is maintained at a predetermined constant level. · In addition, a pipe 43 leads from the pipe 35 and connects with the chamber of the pump 6 as at 44, and this pipe 43 is controlled by a valve 45 so that in instances when 75 .

it is advantageous, a part or all of the water may be introduced directly to the pump 6 by proper control of the said valve 45 and the valve 34 which may be operated to control, as desired, the relative amounts of water added to the air composition mixture and directly to said pump.

In operation of the apparatus^Jto produce fire extinguishing foam according to the present invention, air or other gaseous medium is drawn by the rotary pump 6 inwardly of the funnel 22, and pipes 19 and 18 to the main inlet port 10 thereof. At the same time, rotation of the table or disk 24 of the feeding device 5 discharges the dry foam composition into said funnel 22 with the inflowing air stream at a predetermined substantially uniform rate of feed. Likewise water entering the tank or vessel 20 from, the reservoir 3 enters the tube or pipe 19 through the apertures or perforations 21 therein and mixes with the air and dry foam composition before entering the rotor chamber of the pump 6 through the secondary inlet ports 12 and 13, where it is mechanically generated into a highly stable air foam and discharged at pressures sufficient to enable it to be conveyed or projected for substantial distances.

It will be observed in the arrangement of apparatus illustrated in Figures 1 and 2 of the drawing, that the dry foam producing composition is fed into the inflowing air stream prior to contact or mixture with the water which enters the tube or pipe 19 through its apertures 21. On the other hand-and referring now to Figure 3 of the drawing, a different arrangement of foam generating apparatus is shown wherein the foam producing composition is fed to and mixed with the inflowing water stream.

This latter method of feeding the dry foam composition may be accomplished in several different ways, however, in that shown in Figure 3 of the drawing, the water reservoir may be entirely Eliminated and the water supplied directly to a vortex mixer 38 through a.branch pipe 39α under control of a valve 40, the branch pipe 39α connecting with a supply pipe 39 as shown. Also connected with the supply pipe 39 is a second branch pipe 39b controlled by a valve 46 and connected to the pump 6α so that by operation of the valves 40 and 46 the relative amounts of water admitted to the vortex 38 and directly to said pump 6 may be controlled. The pipe 39α is arranged so that the water is discharged into the vortex 38 tangentially thereof so that there results a swirling or whirling action as indicated by the arrows. ·

In this form, of apparatus the dry feeding device 5α may be the same as that described above in connection with Figure 1 having a hopper. 23α, and a feed table 24α driven by a motor 28α, said feeding device being mounted upon a standard 4α resting or secured upon a base la. As shown in the drawing, the dry foam producing composition is discharged from the feed table 24α and allowed to fall or drop into the vortex mixer 38 where it mixes with, the water therein and subsequently flows with said water through the pipe 19α which leads from the bottom of the vortex 38. In this arrangement an air inlet conduit 41 is connected to the main inlet 10α of the pump Ba and this conduit.41 gradually increases in diameter outwardly from the pump terminating in an upwardly directed mouth 42. The pipe 19α leading from the vortex 38 extends inwardly of this air inlet conduit 41 and terminates just short of the pump inlet 10α so that

2,2 the suction created by said pump and the, flow of the water and dry composition into the pump from pipe 19α draws air from the atmosphere inwardly of the said conduit 41 and entrains it into said pump Ga. The outlet Ha of said pump has connected thereto a hose or pipe line. 16α and nozzle 17α as described in connection with Figure 1 of the drawing.

Still other methods may be employed involving the mixture of water and dry foam composition before contact with the inflowing air stream and, for example, In installations requiring further mixture and dilution of the dry foam composition, an ejector may be disposed in the pipe 19α and supplied with water at medium pressure so that the dry foam producing composition is hydrated and mixed with some water in the vortex mixer 38 and is then transferred, by means of the ejector, to the pump Ga, said ejector functioning to effect additional mixture and dilution of the dry composition.

In practicing the invention, a number of foam producing materials or substances such as saponin, licorice extract, extract of tan bark and the like may be successfully employed with or without an alkaline earth oxide. However, we prefer to use a mixture of licorice extract and an alkaline earth oxide (hydroxide) in dry powdered form. In this mixture the licorice extract may be either primary or secondary, and the oxide (hy- 30 droxide) is preferably calcium, barium or strontium. The percentages of licorice extract and alkaline earth oxide may vary widely but the oxide is preferably present in the mixture in proportions of from 10% to 50% depending upon the 35 stiffness or fluidity desired in the foam produced. Also this relative stiffness or fluidity of the fire extinguishing foam may be controlled within reasonable limits by controlling, through the various valves, the quantity of water supplied to the purap in relation to the feed of dry foam composition. . 'j.

Thus the relative quantities or proportions of air, water and dry foam composition will vary with the quality of foam desired, and using a generator or pump designed to produce foam at a rate of one hundred. (100) gallons per minute, excellent results were obtained by feeding the dry composition at the rate of from one to two pounds per minute and water at the rate of -from ten to twenty gallons per minute. The dry foam composition consisted of equal parts by weight of dry pulverized quicklime (calcium oxide) and dry powdered secondary licorice extract. The resulting foam is more or less fluid but a relatively stiff foam for use on vertical or inverted surfaces was produced by increasing the rate of feed of the dry powdered foam composition to as much as from four to five pounds per minute, maintaining the rate of feed of the water as above. In each instance the pump or compressor was driven at a speed of 3700 R. P. M. and the discharge pressure in the foam line was between ten and forty pounds per square inch depending upon the size and length of the foam piping employed.

The invention is not limited to the use of the particular type of dry feeding mechanism illustrated and described herein and we may, for example, obtain satisfactory results from other γθ types of dry feeding devices such as embodying the conventional star wheel or worm type of feeder. The invention, therefore, is not limited to the foregoing disclosure, and it is intended that changes and modifications may be made and 75

19,095 3 incorporated in said invention within the scope of the annexed claims.