US1781293A - Portable foam-producing apparatus - Google Patents

Description

Nov. 11, 1930. J. A. M CRACKEN PORTABLE FOAM PRODUCING APPARATUS Filed Sept. 28, 1927 llll INVENTOE Patented Nov. 11, 1930 JAMES A. MoonAoKnn, oFLos Antennas, CALIFORNIA PORTABLE FOAM-PRODUCING APPARATUS Application filed September 28, 1927. Serial No. 222,635.

The art of extinguishing fires in general, and particularly oil fires, by means of Foa1nite or Firefoa1nis very well known and understood. ltconsists in bringing into ad;

. 5 mixture solutions of (a) aluminum sulfate and (6) hydrogen sodium carbonate and a substance having the property of increasing.

thesurface tension of aqueous liquids, such for. instance as glue or licorice. By the ad- 10. mixture of said solutionsin proper proportionsa very dense and tenacious foam is produced which, as it consists mainly of water, is'a highly eflicaciousand valuable agent for extinguishing fires. y

' For reasons which it-is not-necessary to elaborate here the foam itself cannot be pumped through aline for any great distance,

audit is therefore requisite tobring the solutionstogether at or near the seat of the fire.

Where largev installations such as oil tank farms are to be protected, it is customary to install separate tanks and pumps for the two solutions and separate pipelines forthe distribution ofithe solutions over the area to be protected, but as this calls for a heavyinitial investment it is common practice to take care of smaller needs by means of portable extinguishers. p i

. Heretofore these portable extinguishers or fFoamite carts have consisted of a single tank. mounted on. light running gear, the.

wholebeing of such weight as to be manipulated by one or two men. Inside the apparently single tank referred to is placed a smaller tankiofless capacity, the smaller tank beingfilled with one of the solutions while the space between the two tanks. contains the other. An: inside valve operated. from the outside establishes a connectionbetween the twobodies of liquid, the carbon dioxid generated by thereaction creates a high pressure withinthe system, and the foamis thus forced out through an opening in the outertank and through a hose to the seat ofthe fire.

' This-arrangement,.while simple and convenient, has two very serious. disadvantages. The first is that the pressure created within the tank and the high velocity at which the foam is discharged tend to breakdown-the to foam and greatlyreduce its. volume. This.

tendency manifests itself to such an extent that whereas properly proportioned foam solutions should increase in volume ten times, that is, one volume of the combined foam solu.- tions should produce ten volumes of foam, the actual increase in volume in the portable tank apparatus is seldom more than three to one. The second is the very limited capacity of an apparatus of such size as to' be truly portable. For instance, a tank cart such as above described, having a nominal capacity of forty gallons but actually charging only thirty-three gallons of solutions,-would have a discharge capacity of 33 3 orlOO gallons of foam. This small quantity offoam will 05 take care of but a trifling fire, and as the apparatus requires some timeto recharge, its range of usefulness will obviously be extremely limited] U p The object. of my invention is to providea portable unit weighing approximately half as much as a charged forty gallon tank extinguisher, which will give an absolutely continuous and uninterrupted. stream of foam. which may be kept constant over a rather wide range of controlled variation, and which at its normal or average operating rate will yield one thousand gallons of foam, or. ten times the total capacity of a forty gallon tank extinguisher, every minute of its operation. y

The usefulness and many further advan tages of my invention will be apparent from an' inspection of the attached drawings and the followingdescription thereof. In these drawings, whichxillustrate a preferred applis5 cation of my invention Figure 1 isa plan drawingof the assembled apparatus. y

Figure?) is a side elevation of theassembled apparatus-with one wheel of the cart removed. on

Figure Sis an end elevation of the assembledapparatus.

Figure 4 shows, ininterior'elevation, one of the mixing. and dissolving. units indicated at 1 -1"r=1 1""in Fig.1, four of sucliiunits 93 being used in the complete apparatus.

Figure 5shows in inte rior elevationa pre ferred type of valve for use between the mixer 2 and the dissolver 3 as sh'ownfin Fig. 4.

be repeated.

Figure 6 shows in interior elevation the,

supporting plate which may advantageously be used in the mixing vessel 2 shown in Fig. 4:. w r I Referring to FigsJSand 4, the four units 1 and 1 are supported on a substantial axle l, supported in turn by the two wheels 55, the whole forming a rigid unit capable of being easily moved. A relatively light handle 6 is attached tothis unit to afford a handhold for one or'tWo men, one being quite sufficient unless the machine is being handled 'over very soft or rough ground.

-'The four units 1 11 ,1 -are identical, 7 and'a description of one will suffice for all. Aunit is composed o'f'the'mixing vessel 2 (see-Fig. l) and the dissolving vessel 3, the former being open at thetop and the latter substantially closed; These two vessels are connected by a relatively wide pipe 7-7 in which is interposed a valve 8-, preferably of the quick opening type, As all the valves hereinafter referred to are of this type, the

' qualification will be understood and need not As illustratingjtherelative proportions of the various parts of this unit but not as limiting'my inventionto'apparatus of any specific size, I" will state that an apparatus" consisting of? four units 1 1 1" ana-havmg a delivery capacity of from 50 to 200 gallons per minute of solutionfnot foam) will function-properlyif the mixfer2 is 15 in diameter and 15 high, the dissolving vessel 3 may be'12 in diameter and 24 high, and the connecting pipe 7 maybe 3 standard pipe size; 1 Y

The mixing'vess'el 2 teria'l in two of the units and the alkaline or bfmaterial in the other'two) and to drop this charge intofthe dissolving vessel'3 when the valve8 is opened. The charge -isalways introduced as a dry'powder, butit may be] dropped into?) either in its original'dry con- 'diti'on or'itmay be firstbroug'ht tothe con: vsi'stency of athin paste 'orcream by the addition ofwaterj In the first alternative it is so -h'referable to omit the v alve8 famine. line 7 andiuse in its place a valve of the general construction shown in Fig 5. i This valve consists of an nverted seat 9' formed in the lower l 'n f i 7'wvliich should in this case be enlar'ged to say 5" or 6" diametere t and a conical valve 103 suspendedlfrom a hand 1e 11 which is pinned i into a projection from'theside'of the pipe 7"asatQ12. Th e' outer end of this handle should be heavy enoughjto support the weight of the dry charge, whichf on lifting the" handle 7 (the 7 charge beingv a" dry and fiuent powder) will immediately run enmasse intothe dissolving; vessel-3. ;,In this case, of'jcourse, no waterisf admitted into vessel 2 I v v hasf orits object to receive a previously weighed ch r e f dry P e c emical (the-acid or a. ma-

the inner wall 'of the vessel 3.

In case it is preferred to convert the dry charge into a paste or cream before dropping it into vessel 3,"it is desirable to place in vessel 2 the supporting plate shown at'13 in Fig 6. This support for the powdered charge may be fiat, but is preferably a spheri- V cal segment the chord. of which is about onethird the diameter of vessel 2/ If a plate of these proportions fails to substantially support the charge, because of unusual dryness of'the powdered material, a wider or a flatter plate may be substituted. This plate is sus-V pended inthe 'diametric center of the vessel t and a short distance from the bottom, as in dicated at'13'in Fig. 6, by any convenient required for creaming the charge is introduced either "over the side by-m'eans of a hand operated valve 26 and curved jet 15 7 (see Fig.4) or preferably at the center as indicated at '16 inFig. 6. The'valve indi cated'at 16 may be so constructed that it will be opened and the'water released into vessel 2 byresting on it the weight of the canister orcontainer by means of which the charge of powder is introduced into vessel 2;

Several well known types of valve are suited to' this use, the particular type of valve being no part of my invention.v 1

Whether the powdered'chemical be intro 8 is closed; The chemical; thus introduced 80' 7 means such as the light rod's'14.- The water Q5 ducted-into the dissolving vessel3 in. the form I of a dry-powder or in'the form'of a cream, it immediately passes to the bottom of the ves sel 3, an'd,"as" soon as vessel 2 is empty, valve. 7

ice

into '3; will come torest onaflat plate 17 supportednearthe bottom of 3 as by'the studs 18. -This; plate should be of such size} andform that it will leave a narrow annular 1 wide in the particular v;

opening 22 (say T1II sizeabove referred to) between its edge and The pipe t 19 controlled by'the valve 20 is introduced through the wall of vessel 3 at any convenient point and is carried downward therein to a short=distance fromthe plate 17 Water entering through i this pipe and projected through'a narrow annular sl-ot'for'med by the approach of the carefully "squared end of the pipetolplate' will' spread out to :form a sheet of 'watermoving rapidly towardthe sides of'vessel ig and flowing downwardly over "the edge "of plate 17, This sheet; of water will rapidly undermine and dissolve completely dissolved.

In assembling a complete apparatus as 1 shown in Fig. 1"fro'm four units as shown in Fig. 4:, certain arrangements ofthe various water and: solution connections are a'dvan hose connecting the apparatus with any convenient source of water under pressure.

From this standpipethe water connections to each mixing vessel (each such connection being controlledby a valve 26 -26 .are taken, and also the water connections 19 19 controlled by valves 2O-20 to each of the dissolving vessels 3.

The solutionoutlet pipes 23 are each controlled by a valve 30, and these pipes are all gathered into a some; manifold 29 within which, by means of channels not shown, the solutions are grouped according to their naturethat is .to say, the two a solution outlet pipes are connected to one channel terminating in a hose union 31, while the two (2 outlet pipes are similarly connected to the single hoseunion 82. By provisions such as these, which of course are not strictly essential to the Working of the apparatus, the number of outside connections may be reduced to three, viz: a single inlet connection for water, a single outlet connection for a solution and a single outlet connection for l) solution. The .two outlet connections are intended for the attachment of individual hose lines, which for convenience may be wrapped or tied together along their length, by means of which the solutions are separately conveyed to any preferred type of mixing and distributing head located in or adjacent valve 8%, the purpose of such pipe being to drain. from the exhausted vessel the water with which it will be filled at the end of the dissolving period. These valves should also be connected together in pairs (a pair being an a vessel and a b vessel).

For a unit of the size above stated a 2 pipe size water inlet and two 1 pipe size solution outlets are proportionate to the other dimensions stated.

If the solutions are separately conveyed to and admixed at the seat of the fire it is perfectly practicable to get ten volumes of foam per unit volume of total solution used. To obtain such expansion it is desirable to make the strength of the a solution equal to 0.6

poundlaluminum sulfate (containing water of crystallization) per one-half gallon of water used in making such solution, and to make the strength of the 6 solution equal to 0.35 pound hydrogen sodium carbonate plus 0.05 pound dried and powdered ex-.

tract of licorice per one-half gallon; a total of 1 pound total chemical to one gallon total water used. lheseproportions are preferred proportions only, and my invention does not lie in the strength or character of solution produced except insofar as certain chemicals and general proportions are well known to be requisite to inakea foam of satisfactory volume and stability.

In the operation of my apparatus the following steps are taken. A water hose is run from union (Fig. 1) to any adjacent sup ply of, water under pressure, all valves-26 or 16, 8 01-10, 20, 29 and 8l being closed. The two solutionoutlets 31 and 32 are also connected by suitable hose lines to any preferred form of mixer and distributor located at or near the fire. The apparatus is now ready for use.

The chemicals required should be previously weighed out and put up in packages marked respectively a and b. For a solution supply of 100 gallons per minute the a package should contain pounds of finely pulverized aluminum sulfate, dried to the point.

where all free water is driven off and the powder is loose and fluent but not dried so faras to drive oif any appreciable proportion of the water of crystallization, The 5 package should contain 35 pounds of baking soda (hydrogen sodium carbonate) and 5 pounds of extract of licorice (or other stabi-.

lining agent) which has been previously dried and reduced to afine powder, these twabodies being thoroughly and evenly intermixed prior to weighing. As both of the reagents named are liable to take up some water if exposed to the atmosphere and toform a crust or balls of solidifiedpowder, the packages should be of metal (ordinaryslip top milk cansare suitable) andthe joint should be waxed or otherwise sealed 111 such manner thatthe seal may be readilybroken. A supply of such packagedchemicals should always he on hand, and if protected from the air as described will keep indefinitely.

The next step, assuming that the chemicals are to be dropped into vessel 3 as adry powder, is to dump a charge of a powder into one of the mixing vessels, as 2 in Fig. 3, and a charge of the 5 powder into the opposite vessel 2*. The valve 10 (Fig. 5) is then opened and the powder dropped into the two dissolving vessels 3 and 3", after which valve 10is closed.

If the powders are to be passed into the dissolving vessels as a cream, two Valves 2O and 20 are opened, and just prior to dumping in the powders thetwo valves 26 and 26 are opened, the streams of water from these valves carrying the powder instantly into the vessels 3?" and 3 Or if the arrangement shown in Fig. 6 is used, the weight of the canister will automatically open valve 16 and flush the powderinto vessel 3 at the instant of dumping. In either case the valves 20 and 20 are closed as soon as the powder has passed down into vessels 3 and 3.

The valves 30 and 30 (one pair only) are then opened, and thereafter .theevalves 20* and 20, the latter admitting water into ves sels 3 and 3 and forcing the wand b solu time out of outlets 31 and 32- through the 7 corresponding hose 111188 00 the mixing-head where they are mternnxed and produceithe desired foam.

While the first pair of'dissolving vessels are beingdischargedthe second pair are bei 7 ing charged with chemicals (either dry or in theform of a cream) and are thus ready to deliver solution on closing the first pair of solution valves and 30 and, opening the opposite pair, and opening the second pair 7 of water valves'2O and 20". If the four 30 valves were replaced by check valves the necessity for reversing these valves would be avoided, as their sole purpose is to prevent solutions leaving one pair of dissolving vessels 8 under pressure from flowing back into the opposite pair.

lVh'en discharge of the first pair'of vessels 3 is completed the two drain valves 34.011

such vessels should be momentarily opened to allow any water remaining in; such vessels I to run'out.

pressure in a flow-stream means for'int'e'r mixing said fluent-masswith said fiow-stream and for producingaqueous solution'of the powder therein contained and means for conveymg said solution to apoint ofuse thereof, the conveyance ofsald solution to said point of use being brought about solely, by the pres sure of the entering water."

2, An apparatus as and for the purpose described in claim 1,'in whichthemie'ans for lntermixing water with powder to the consistencyof a fluent mass consists of afplate In witness that I elaim the foregoing I have hereunto subscribedm day of'sep mber, 1927. 7

, The above said charges of chemicals, used duction of substantially 1000 gallons per minute,'willsufiice for two minutes operation, allowing the same period oftime for thesimple' operations of draining the miX-' atarate of 100 gallons total output of solu-I Vtion per minute, equivalentto a foam prop ing vessels, dumping in the dry charges, fiush- I v ing them through or allowing them to run through into vessels 3, andg'closing the two-v valves 20. It therefore requires noundue haste on the part of a single operator to keep this-apparatus delivering foam continuously'if the operator be kept supplied with the packaged chemicals within easy reach. a I

I claim as my invention- I 1 An apparatus for producing a fire-foam solution, comprising: a hopper forreceivingv a supply of a soluble powder; a substantially 1 7 closed vessel in fixed position beneath said hopper means for downwardly directing a jet of water into saidhopper and for inter- I mixing said water with said powder to the consistency of a fluent mass; a means of communication between said hopper and said vessel; a controllable closure-withinsaid communication means for. permitting said fluent mass to pass at will into said vessel; ,means for admitting water into saidves el under y nam'e this 14th JAB ins. MCCRAGKEN.

Images