US2327335A - Pressure proportioner - Google Patents

Description

-ugo i943@ L., W.; BQERNER ETAL 2327,335 A PnEssUBEYPRoPoRTIoNER Filed April le, 1942 2 sheets-sheet 1 ao Y if., /L V l ZEZOI" K LEWlS W. EOERNER FRANCS J. HoeenmlLu-:R

Aug., 24, 1943e L. w. BOERNER TAL 2,327,335

PRESSURE PRoPoRTIoNER Filed April 16, 1942 2 Sheets-Sheet 2 R am f. ON B vw wwf 5J Mm Kfm UNITED STATE Patented Aug. 24, 1943 PRESSURE- PROPORTIONER S PATENT OFFICE Application April 16, 1942,Serial No. 439,210

4 Claims. (Cl. 299-84) This invention relates generally to apparatus for use in the generation of mechanical or air foam employed in the extinguishment of fires and more particularly to an improved construction of apparatus for introducing a foam stabilizing solution into a stream of water.

In the production of the so-called mechanical or air foam, the usual procedure involves flowing a high velocity stream of water laden with a foam-forming substance through a conduit to a point therein where the stream is finely subdivided or dispersed and where a suitable gas (usually air from atmosphere) is entrained in such manner as to cause a mingling of the liquid and gas as they move in the conduit toward the point of discharge therefrom. Typical of this method of producing mechanical foam is that which is described in United States Letters Patent No. 2,106,043, granted January 18, 1938, and No. 2,198,585, granted April 23, 1940.

In order to insure the production of foam oi the desired uniform quality, it is necessary that the rate of introduction of the foam-forming material into the owing stream of water be proportional to the rate of flow of the Water, while in order to insure an adequate projection of the foam from the discharge nozzle it is necessary to maintain a considerable head of pressure upon the Water stream. It is among the principal objects of this invention to provide an apparatus by which both of these desired objectives may be secured;

More specifically, an object of the present invention is the provision of an apparatus which not only insures maintenance of a maximum head of pressure in the water stream to provide lfor adequate projection of the stabilized foam, but which also utilizes the full available head of pressure to inject the stabilizing material into the water stream at a rate which is automatically proportioned to the rate of flow of the v water stream.

so operatively associated with the water conduit as'to insure the continuous introduction of such material into the iiowing water stream until the supply is exhausted, the container being adapted for ready removal and replacement by another filled container should a further supply of foam stabilizer be required. In addition, the container itself is so constructed and designed as to facilitate its being readily and quickly lled with foam stabilizer without incurring foaming of the latter per se.

Still other objects and advantages of the present invention, such as the provision of a unit which isl exceedingly compact and simple in construction, which is readily portable and easily operable without requiring the constant attendance of an operator and which is extremely enicient in use, will appear more fully hereinafter, it being understood that the invention consists substantially in the combination, construction, location and relative arrangement of parts, all as will be described in detail hereinafter, asshown in the accompanying drawings and as nally pointed out in the appended claims.

ln the Isaid accompanying drawings, which illustrate a preferred embodiment of the present invention:

Figure 1 is a side elevational view, shown partly in vertical section, of an apparatus constructed in accordance with and embodying the principles of the present invention;

Figure 2 is a top plan view of the proportioner unit with the cap removed;

Figure 3 is a vertical sectional view of the unit removed from the stabilizer container;

Figure 4 is a horizontal sectional view taken along the 1ine l-li of Figure 3; and

Figure 5 is an `end elevational view of the outlet end of the proportioner unit. Referring now to the drawings and more par'- ticularly to Figure l thereof, it will be observed that the apparatus of" the present invention generally consists of a refillable container li) within which is stored a supply oi foam stabilizing solution and an injecting device l! which is operatvely associated with the container ill for delivering the foam solution from the container into a flowing stream of water at a rate which varies proportionally to the rate of flow of the Water.

, The foam solution injecting unit is shown more particularly in Figures 2 to 5, inclusive, and is' adapted to be detachably connected to the container I0 by the simple expedient of screwing the lower end part I2 into an interiorly threaded fitting i3 With which the container l0 is equipped.

The injecting. unit I i, as most clearly appears in Figure 3, essentially consists of a one-piece body member, the interior of which is longitudinally bored to provide a Venturi tube I4 through which a stream ofv water from a suitable source of high pressure supply is adapted to be projected in the direction indicated by the arrows. The water inlet end of the unit is interiorly threaded as at I5 for connection, by means of a suitable coupling and hose I6 (see Figure l) to a hydrant or other source of water under suitable pressure. The outlet or discharge end of the unit is exteriorly threaded as at I1 for connection, by means of a suitable coupling I8, to a hose I9 through which the water mixed with the foam stabilizer solution is delivered to the point where air is entrained therein and thence discharged in the form of re extinguishing foam. The manner of and means for effecting the entrainment of air or other gas into the stream of water laden with the foam forming substance forms no part of the present invention and, therefore, no detailed description thereof willbe given herein, the present invention being limited more particularly to the means' for introducing into the water stream the requisite quantity of the foam stabilizing solution. It will be understood in this connection that' this invention is not limited to the use of any particular type of foam forming material. Usually this material is in the form of an aqueous solution of a secondary extract of licorice, of saponin or of other suitable substance having the capacity of being foamed when a gas is injected into a solution or suspension thereof.

In addition to the Venturi passage extending longitudinally through the injecting unit II, the latter is provided with a vertically extending the upper extremity of the tube 21 immediately below the lower extremity of the sleeve are a plurality of circumferentially spaced openings 28.

lThe function of this tube 21 and of the said openings 28 therein will presently appear.

As appears most clearly in Figures 3 and 4, the vertical bore 25 formed in the internal boss 26 is disposed interiorly of the circumferential line of the tube 21, this bore 25 being in turn securely tted with a tube 29 which normally extends downwardly into the container to a point just short of the bottom thereof. Due to the location of the supporting boss 26 relatively to the sleeve I2 the tube 29 tted into and supported by said boss is arranged interiorly of the tube 21, which is ttied into and supported by the sleeve I 2. The upper end of the tube 29 is provided with an opening 30 which is in communication with the passage 23 previously referred to, and thus, the lower end of the tube 29 freely communicates with the Venturi passage pressure portion thereof.

It will be understood that in the operation of the apparatus of the present invention, the container III for the foam stabilizing solution is connected to the injecting unit I I, as shown in Figbore or passage 20 of substantial dimension. The

upper end of this verticalpassage is surrounded by an exteriorly threaded neck -2I, which is adapted to be closed by a cap 22 suitably threaded thereon and having a pair of oppc-sitely project- 'ing arms 2221-22a for facilitating screwing of the cap tightly into position. The lower end of the vertical passage 20 is surrounded by the exteriorly threaded sleeve-like projection I2 which is adapted to be threaded into the tting I3 of the container. 'I'he passage 20, which extends substantially at right angles to and is in free communication with the Venturi tube passage, may be termed the lling opening. In addition to the Venturi passage and the said filling opening, the unit I I is provided with an auxiliary passage 23 of reduced diameter which connects the low pressure portion of lthe Venturi tube at the point 24 with a vertical bore 25 extending upwardly into a boss 26 which projects. interi-orly of the central portion of the wall of the lling opening. This auxiliary passage 23 is formed of the intercommunicating angularly related portions as shown in Figure 3, the outer extremities of which are tapped, as at 23a-23a. for reception of suitable closure plugs. The angularly related portions 0f the passage 23 are formed by drilling intersecting holes in the part 24a of the main body member, it being apparent that such construction facilitates locating as desired the position of the point 24 with reference to the low pressure section of the Venturi passage.

Securely fitted into the sleeve-like lower end I2 of the injecting unit is a tube 21, the length of which is determined by the size of the container I0. Generally, this tube 21 is of such length that when the unit II is operatively ccnnected with the tank I0, the tube extends downwardly into the tank for approximately threefourths of the depth of the latter.

Provided in ure l, the container I0 being normally lled with the foam solution to such level as to just about freely expose the openings 28 in the lling tube 21. In this condition of the apparatus, the cap 22 will be tightly secured in place to lclose the upper end of the filling opening. Water under pressure from a suitable source of supply is then delivered by the conduit I6 to the inlet end I5 of the injecting unit I I and passes through the Venturi passage I4 thereof in the direction of the arrows of Figure 3. As the water enters the unit II, a portion of it flows under considerable pressure downwardly through the filling opening and discharges through the openings 28 in the filling tube 21 to ll the free space in the top of the container I0 above the level of the foam solution contained therein. The water which so enters the container through the openings 28 exerts a considerable pressure on the solution in the container I0. Due to the fact that the lower end of the tube 29 is in free communication with the low pressure portion of the Venturi passage at the point 24, there exists a pressure differential between the latter point and the point of application of the water under pressure upon the upper surface of the foam solution, which results in a ow of the foam solution upwardly through the tube 29 and through the passage 23 into the stream of water flowing through the low pressure portion of the Venturi passage I4. This flow of foam solution from the container I0 into the stream of water flowing through the Venturi passage of the injecting unit will continue, of course, so long as a stream of Water under suitable pressure is flowed through the unit and until the supply of foam solution in the container IU is completely exhausted. Inasmuch as the flo-w of the foam solution upwardly through the tube 29 is dependent upon the pressure differential existing between the high and low pressure portions of the Venturi passage, it will be apparent that by proper design of the cross-sectional areas of said high and low pressure portions of the Venturi passage and the proper location of the point 24 in relation to the point of application of the high pressure to the upper surface of the foam solution in the container I0, the ratio of the rate of ow of the foam solution to the rate of ow of the water stream through the Venturi at the point 24 in the 10W passage may be predeterminedly established and maintained.

As the water under pressure from` the source of supply enters the container I through the passages 28 of the filling tube, it is laterally distributed uniformly over and exerts an even pressure upon the entire upper surface of the foam solution, there being little, if any, mingling of the Water and foam solution in the container lll. The openings 28 and the passage 20 leading thereto are of such substantial size that substantially the full head of water pressure is exerted upon the foam stabilizer solution contained in the container I0. As the foam solution is withdrawn from the container for injection into the water stream at the point 24, additional water enters the container so as to maintain a constant pressure head upon the foamsolution until the supply of the latter is completely exhausted, at which time the container l0 will be filled, of course, entirely with water. In such event, the water supply may be cut off and the container l0 drained of its water preliminarily to its being refilled with a further supply of foam solution. Or, if desired, the container I0 when so filled with water may be entirelyremoved and replaced by a second container lled with the foam solution. To facilitate rapid emptying of the water from the container I0 when the latter is not disconnected from the injecting unit Il, any suitable type of quick-acting valve (not shown) may be provided at the bottom of the container, this valve being normally opened for discharge only upon interruption of the water supply and removal of the upper closure cap 22.

In order to refill the container I0 with foam solution after it has been cleared of its accumulated water, it is merely necessary to close the bottom valve of the container and then ll it by Way of the lling opening 2u and the filling tube 2i. inasmuch as the latter projects downwardly into the container for some considerable length, the filling of the container is accomplished with a minimum of agitation of the foam solution and consequently foaming of the latter in the container i@ during the filling operation is substantially inhibited, if not altogether avoided.

it will be understood, of course, that the invention is capable to Various changes and modications Which may be made from time to time without departing from the real spirit or general principles thereof, and it is accordingly intended to claim the invention broadly, as Well as specically, as indicated in the appended claims.

What is claimed as new and useful is:

l. in an apparatus for injecting a solution of foam forming material into a flowing stream of Vwater, a device adapted to be interposed in a conduit for delivering the water under pressure from a source of supply to a point of discharge, said device being characterized in that it is provided With a Venturi passage extending longitudinally therethrough and with a pair of passages extending laterally of and in free communication respectively with the high and low pressure sections of said Venturi passage, the lateral passage in communication with the high pressure section being of substantially greater cross-sectional area than the lateral passage in communication with the low pressure section, a pair of tubes respectively fitted into said lateral passages, and a closed container for the foam forming material secured to the device aforesaid in embracing relation with respect to the said tubes, the lower ends of both tubes being open and the tube in communication with the high pressure section of the Venturi passage having means for permitting the delivery of Water from said high pressure section directly upon the upper surface of the solution in said container whereby said solution is forced upwardly through the other tube into the low pressure section of the Venturi passage.

2. In an apparatus for injecting a solution of foam forming material into a flowing stream of Water, and which device is adapted to be interposed in a conduit for delivering the water under pressure from a source of supply to a point of discharge, an injecting unit characterized by the provision of a Venturi passage extending longitudinally therethroughand with a pair of auxiliary passages extending laterally of and in free communication respectively with the high and low pressure sections of the Venturi passage, the lateral passage in communication with the loW pressure section of the .Venturi passage being extended to a point interiorly of the lateralpassage in communication with the high pressure section of the Venturi passage, a pair of tubes respectively fitted into the terminal extremities of said lateral passages with the low pressure tube disposed interiorly of the high pressure tube,

and a normally closed container for the foam forming solution secured to the injecting unit with the tubes aforesaid projecting interiorly thereof, the lov.1 pressure tube having its lower end open and terminating just short of the bottom of the cbntainer, While the high pressure tube is provided in the portion thereof immediately below the top of the container with a plurality of openings through which Water from the high pressure side of the Venturi tube may be delivered upon the upper surface oi the solution in the container.

3. In an apparatus of the character dened in claim 2 wherein the lateral passage which is in communication with the high pressure section of the Venturi tube entends freely to either side of the Venturi tube axis, one end of said lateral passage being in the form of an annular iiange threaded to receive a closure cap, while the oppoes site end ot said passage is also in the form oi an annular ange to which is adapted to be thread edly secured the container for the foam forming solution.

a., In an apparatus of the character dened in claim 2 wherein said passage which is in comreunication with the high pressure section oi the Venturi tube is extended to one side of the injecting unit to provide an opening through which the roam forming solution may be poured to fili the container and wherein the tube which is con nected to said passage in continuation thereof is of substantial length and is open at its bottom end.

LEWIS W. BOERNER.

NCIS J. HOGE l all mr-4

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