US2419146A - Booster pump with vapor separating means - Google Patents

Description

April 15, 1947.-

E'. J. KIMM ET AL BOOSTER PUMP WITH VAPOR SEPARATING MEANS F'iled June 19, 1944 2 Sheets-Sheet 1 1/2 70 s .Z'waZd IZimm.

BOOSTER PUMP WITH VAPOR SEPARATING MEANS E J. KIMM ET AL Apr-111 5 1947.

Filed June 19, 1944 2 Sheets-Sfieet '2 v Fwald .Z'ffz'mm.

nauZJL Hefimann Patented 'Apr. 15, 1947 UNITED s 'r Ewald 'J. Kimm and 3 Dayton, Ohio, assignors pany, Dayton, Ohio, a corporation of Ohio Application June 19, i944, Serial No. 541,016 14 Claims. (Cl. 222-189) The present invention relates to a fuel tank and pump arrangement that is particularly adapted for the fuel feed systems of aircraft engines, to effect the continuous delivery of liquid fuel to the engine regardless of the condition of the fuel in the tank caused by violent maneuvers of the aircraft tending to uncover the pump inlet and by reduced pressures on the fuel at high altitudes tending to vaporize the fuel and cause vapor lock in the system.

invention deals with an More specifically the arrangement whereby a localized pond of liquid fuel above the inlet of a pump is separated from I an open-ended secondary container or stand pipe within an aircraftfuel tank around and above a pump inlet to receive fuel from the pond inthe tank. and having means therein for agitating the fuel to create vapor formation and separate the pure fuel from the bubble-charged fuel, which said bubble freed fuel is received by the pump for delivery to the engine.

Another object hereof is to provide a stabilizer device mounted on the bottom of the fuel tank preferably in spaced relation to the tank bottom wall so that the liquid fuel can flow therein from the bottom of the fuel tank and be circulated in the stabilizer device while being freed from s i PATENT OFFICE BOOSFEEEPUMP VZIEQPOR SEPARATING v emard R. Bellmann, to Curtis Pump Combottom of the tank, the pump and the stabilizer preferably constituting a unitary structure that may be removed bodily from the tank.

' A further object is to provide baffling means of the invention vapor charged bubbles whereby pure fuel is fed to the pump.

Another object is to provide deflector means in a stand pipe around the intake of the pump for carrying away gas and vapor charged bubbles that are induced by the pump propeller or beater device and to direct the bubble-rich fuel to the surface of the pond in the stand pipe and thereby permit the bubble-free fuel to flow axially down to the pump.

the pump propeller so within a stabilizer or stand pipe to break up whirlpool action in the fuel flowing to the pump, to direct the fuel axially to the pump inlet and to minimize surging of the fuel when the tank is suddenly tilted.

It is another object hereof to provide a device for guiding the bubble-rich stream of fuel from that it will not interfere with the gas-freed liquid fuel that is flowing axially to the inlet and so that it will sweep new fuel into the container. This device in the present disclosure preferably embodies an upwardly flared or cupped annulus positioned between the wall of a agitator of the pump.

A further object of the invention is to provide a baiile construction for a booster pump assembly which is readily mounted in association with stabilizer chamber and the the pump without alteration or disassembly of construction and Another object is to provide a well-definedv localized or substantially isolated volume of fuel in the fuel tank that is free from extraneous matter and flows axially ,to the intake throat of a pump to constantly supply sufficient pure fuel to prevent uncovering of the pump intake.

A further object hereof is to provide a pump 7 and stabilizer assembly that is mounted on the the pump unit. I i, AdditionaL-object's, aims and advantages of the'invention contemplated herein will be apparent to persons skilled in this art after the operation of the fuel stabilizer is understood from the within description.

It is preferred to accomplish the numerous .ob-

jects hereof and'to practice the invention in substantially the manner hereinafter fully described and as more particularly pointed out in the claims, reference being now made to the accompanying drawings that are a part hereof.

. On the drawings? Figure 1 is a vertical axial section on the plane of line I--Iin ,Figure 2, with the pump motor in elevation, showing details of the booster pump and the stabilizer structure assembled therewith. and showing the manner of providing a unitary assembly adapted for bodily removal from the tank.

Figure 2 is a top plane view of the structure shown in Figure 1 with the fuel tank removed; and Figure 3 is a fragmentary vertical axial section, similar to Figure 1 showing a modified structurewherein the stabilizer cylinder is mounted directly upon the bottom wall of the tank and the pump mounting is separate from the stabilizer device. z

The drawings are to be understood as being more or less of a diagrammatic or schematic character for the purpose of disclosing typical or presurface of the throat ring 2|.

ferred forms of the improvements'that are contemplated herein.

Referring to Figure l, the electric motor booster. 1

pump unit, generally designated by the numeral I; is mounted upon the bottom wall H of a tank T which contains a pond of liquid fuel for-v an aircraft engine, said tank being-ventedthrough' aperture V in the top wall. There is an opening 0 in the bottom wall ll of the tank through I which a portion of the pump unit projects. It

will be understood however, that the arrangement.

tion the interior-of which .constitutesthe 10 .151}? pumping chamber I6 of the pump. The volute pumping chamber i6 communicates with and discharges through an outlet stub |6a that leads to the engine-driven fuel pump of the aircraft engine (not. shown).

Th upper portion of the chamber l definring 2| by means of the cap screws 24 that anchor the throat ring in its seat on the pump casing. These legs have lateral flanges 33 at their upper portion that are secured to and carry an inverted hollow frusto-conical guide or shield 34. This guide shield has upstanding ears'35 at its upper edge to receive the frustc-conical wire-mesh screen 36 therearound, the screen bemg anchored to the ears'by'washer screws 31.

As shown in Figure 2 the frusto-conical screen" wall 36 hasa wire-mesh top wall 36a. The tapered side wall of the screen 36 extends down into close proximity to the upper surface of throat ring 2| asshown in Figure 1;

The small lower end of the inverted frustoconical guide or shield 34 is in spaced relation to the throat ring and is also above the agitator or pump propeller 29. The shield 34 is supported upon the throat ring and the pump casing, and

ing portion is formed with an outturned annular flange l1 having a shouldered portion |8 around the upper surface of its margin to seat it upon the adjacent outer face of the tank bottom wall II' I around the openingO, while another portion'of th flange enters the opening 0. This flange I1 is maintained in place by a plurality of cap screws v I9 that pass through it and the bottom wall II and enter threaded recesses in a mounting ring 20 that is seated inside the tank on the face of the bottom wall I I around opening 0.

th screen 36 is carried by the shield. This effects .a pump. assembly, a portion of which projects into the tank T and a portion is pendant outside the tank. The whole unit is mounted upon the bottom wall ll of the tank in a manner that permits the ready removal of the assembly as a unit from the tank merely by releasing the screws l9 from the internal ring 20 and I then withdrawing the unit through opening 0.

When the bubble-rich fuel streamis thrown outward by the agitator or propeller 29 this stream will pass between the throat ring 2| and I Q the shield 34 and then through the screen 36.

This stream is directed upwardly by the concave face of a cup-shaped annulus or deflector 38, the

An annular throat ring 2| has a shoulder 22 at its margin that is positioned in a seat 23 around a central opening to the chamber l6. Cap screws are passed through the throat ring 2| and enter threaded recesses to anchor the ring in place.

The pump impeller comprises a rotatable disk 25 having a hub 26 that is suitably secured upon the adjacent end portion of the rotatable motor shaft l5, and the upper'face of this disk is pro- I vided with a. plurality of radially positioned upstanding fins or vanes 21, the upper edges of which vanes are in'close relationship to the underadapted to receive the fuel axially through the central opening 2|a of the throat ring 2|, and the peripheral edge of the impeller disk 25 and the outer ends of the vanes or fins 21 are adja- The impeller is cent the volute pumping-chamber IE to effect the discharge of fuel under pressure into said pumping chamber in the usual and well-known manner of centrifugal pumps.

A collar or sleeve 28, surrounding the motor "shaft i5, is bottomed upon the upper end of the impeller hub 26. A propeller or agitator 29 of the lnclir'ied'blade type is secured to the shaft l5 by a nut 30 that is screwed upon the threaded portion of the shaft to clamp the central portion of the propeller against the upper end edge of the sleeve or collar 28 so'that the propeller will rotate with the shaft and the pump impeller. The pro eller 29 is effective to agitate and beat fuel abo t to enter the pumpfor liberating bubbles of gas and vapor from the liquid and create a lateral or radially outward stream of bubble-rich liquid.

A plurality of legs 8| having laterally bent feet 32 at their lower ends, are secured to the throat wall of which is concavo-convex in cross section. This deflector is secured to the casing flange H by means of cap screws 39 threaded into the flange Within the tank T there is provided a localized stabilizer chamber 42 .deflned by an openended elongated cylinder 43 the upper end of which is spaced from the top tank wall and the lower end of which is supported in spaced relation to the bottom tank wall II by means of a plurality of feet 44 carried by the casing flange .li. Upstanding portions of the feet 44 are secured in any manner to the outer surface of the cylinder 43 and fiat lateral portions thereof are apertured to receive cap screws 45 threaded into the flange ll of the pump casing. The cylinder 43 is constructed and arranged to provide communication with the bottom of the fueltank by spacing the lower end of the cylinder away from side or end edges of these baflle plates 41 abut I the inner surface of the cylindrical wall 43 and are secured thereto by soldering, brazing or in any other suitable manner. As shown in Figure 1, the lower edges of these baffle plates extend across the top edge of the annular deflector 38, and their centrallower portions are provided with upwardly extended recesses 48 to permit them to bridge across adjacent portions of the screen 36. The baffle plates 41 divide the lower portion of the stabilizing chamber 42 within the cylindrical stack 43 into a plurality of quadrant-shape compartments above the plane of the top of screen 36 as well as between the sides of the screen and the chamber wall 43.

. charge the gases. and vapors through the tank ventV.

bubble-rich stream.

pended claims.

gether provide a unitary assembly which may be bodily removed from the tank merely by removing the cap screws l9.

In Figure 3the pump assembly and its screenprovide one unit which is demountable from the flector 38 and the cylinder 43 the pump and screen unit, and are individually secured to the bottom wall H of the tank by means of cap screws 49 and 50, respectively, threaded into the bottom wall H. The deflector and cylinder may be separately removed whenever desired.

The stream of bubble-rich liquid thrown radially outward by the propeller 29, after passing through the screen 36, is deflected upwardly by the cup-shaped annulus 38 as indicated by the arrows in Figures 1 and 3. The stream then moves upwardly between the baflle'plates 41 adjacent the cylinder wall drawing therewith fresh fuel from the main pond in the tank through the passageway 46 as shown by the arrows. This drawn-in fuel replenishes fuel pumped out of the chamber 42 by the impeller 25. The rising streams merge and bubbles therein rise to the surface of the pond where they burst and disto the atmosphere Bubble-freed fuel flows downwardly between the baiile plates through screen 36 and the guide cone or shield 34-back to the propeller which moves the fully liquid material to the impeller while throwing out a radial guide shield cannot swirl.

tank by removing the cap screws l9. The de-1- are separate from" tank, said around said direction of fiow screen encompassing said agitator; a container screen constituting a stabilizer chamber receiving fuel from the lower portion of said tank to constantly maintain a localized pond of fuel into which-said agitator ejects the bubblestream, said agitator being adapted to move fuel downward in an axial direction; and means within said container for changing the of the bubble stream.

3. In combination with a main tank adapted to contain a pond of liquid fuel and having an opening in its bottom; an upstanding secondary container mounted in said tank around said bottom opening to define-a stabilizer chamber within said tank for receiving liquid fuel therefrom to maintain a localized pond of fuel within the chamber having communication at both the top and bottom thereof with said tank; a boOster-punip. communicating with the bottom of said container through said tank opening and having an agitator for ejecting a radial stream of bubbles into the localized fuel pond for release at the top thereof; a deflector for directing the bubble-stream fuel away from the fuel The fuel current to the The cylinder 43 thus provides a localized pond Q of fuel within the main pond in the tank so that only a relatively small portion of the whole body of fuel is treated or stabilized by the pump propeller and this small portion is thus more thoroughly treated for prompt feeding to the pump.

be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by It will, of course,

We claim as our invention:

1. In a fuel system for an aircraft engineincluding a tank adapted to contain a pond of liquid fuel and having an'opening in its bottom wall; the improvements .of a pump casing mounted on the tank around said opening; a pump impeller in said casing; an annular inlet throat overlying said impeller; an agitator adjacent said throat for ejecting a stream of bubbles radially away from said throat; a screen encompassing said agitator; means in said tank receiving fuel therefrom for maintaining a localized pond of fuel around and above said screen; and an annular deflector within said means beyond said agitator for directing the bubble stream upwardly in the localized pond of fuel.

2. In a fuel system for an aircraft engine inthe scope of the ap- I entering said chamber at its bottom; and baffling means adjacent the deflector forbreaking up eddying of the bubble current and for recirculating the fuel in said stabilizer chamber.

4.'In combination with a main tank adapted to contain a pond of liquid fuel and having an opening in its bottom, a booster pump assembly comprising an open-top casing secured to the tank around said opening and defining a pumping chamber communicating with the tank, an agitator coacting with the pump, a liquid pressuring impeller in the pump casing, a screen mounted on said casing, said pump assembly constituting a unitary structure adapted for bodily removal through said tank opening; a secondary container mounted on said tank around the opening to define a stabilizer chamber within the tank and communicating with the tank at its lower end for receiving fuel from the lower portion of said tank, an upwardly flared deflector mounted on the tank wall within said container to direct in an upward path fuel entering the lower end of the container from said tank, and bailiing means carried by said container above said deflector in screen. I

A pump and stabilizer unit comprising a pump casing defining a pumping chamber with a central inlet and a peripheral, outlet, an impeller in said casing arranged for centrifugally discharging liquid from the inlet to the outlet, an agitator mounted for co-movement with the impeller in advance of said inlet, a container for immersion in a pond mounted on said casing defining an open ended stabilizing chamber forcontainer for insertion in the tank to define an open ended fuel stabilizing chamber around the inlet of the pump in free communication at both open ends thereof with tank.

'7. A liquid stabilizer and booster pump assemthe lower portion of the bridging relation to said bly comprising an open-toppedcasing definin a pumping chamber and having an annular mounting flange therearound, means for attaching said flange to a tank wall for removably securing the casing to a tank, a liquid agitator associated with said pump in advance of said casing, a liquid pressuring impeller in said casing arranged for discharging liquid into said pumping chamber, a throat ring mounted on the open top of the casing to direct liquid to said impeller, a tapered shield in spaced relation from said throat ring for delivering liquid to said agitator, a screen surrounding said shield, a container mounted on said casing flange surrounding said screen to define a stabilizing chamber for receiving liquid adjacent said mounting flange, an annular deflector disposed between said screen and said container arranged for directing liquid toward the end of the container remote from the mounting flange, and radially disposed 'baiile plates in said container bridging said screen for breaking up swirling motion of liquid in the container.

screen in the path of said lateral stream of bubble-rich liquid for deflecting said stream to'cause the stream to travel around the screen, and upstanding 'baflles overlying the top and sides of the screen for breaking up swirling motion of v the deflected stream of bubble-rich liquid.

8. A liquid stabilizer and pump assembly comprising a casing having a central inlet and a peripheral pumping chamber communicating with the inlet, an agitator in advance of said inlet, a

the end of the container remote from said casing,

and baflling means in said container bridging said screen and arranged for breaking up swirling motion of liquid in the chamber defined by the container.

9. A pump and stabilizer assembly comprising an upstanding container arranged to receive liquid at its lower end and define a stabilizer chamber, a pump communicating with the bottom of 5 the stabilizer chamber, an agitator on said pump for expelling a radial stream of bubble-rich liquid into the lowerportion of said chamber, a deflector in said chamber arranged for directing the bubble-rich stream upwardly in the chamber, and baffling means above said deflector for breaking up swirling motion of the liquid in the chamber.

10. A pump assembly comprising a pump, casing having an inlet, an inverted cup-shaped screen overlying said inlet, and upstanding radial baflles exterior of said screen and overlying the screen at the top and sides thereof, said batlles extending radially beyond the screen to present bafiie faces of appreciable width effective for stopping swirling of fluids around the screen.

11. A pump assembly comprising a pump having an inlet throat, an inverted cup-shaped screen overlying said throat and extending upwardly therefrom, an agitator within said screen arranged for ejecting a stream of bubble-rich liquid away from the inlet of the pump, and an 13. In a fuel system for an aircraft engine including a tank adapted to contain a pond of liquid fuel, the improvement of a pump and stabilizer unit which comprises a pump having an inlet, a pump impeller in said pump for receiving fuel from said inlet, an agitator in advance of said inlet arranged for ejecting a stream of bubbles radially away from the inlet, a screen encompassing said agitator, a container for maintaining a localized pond of fuel around and about said screen,- and deflector means within said localized pond of fuel in said container arranged for changing the direction of flow of the stream of bubbles to cause said stream to draw additional fuel from the pondin said tank into said container.

14. A pump and stabilizer assembly comprising an upstanding member adapted, to be mounted in a pond of liquid to define a localized chamber in communication with the pond at its upper and lower ends, a pump having an inlet arranged for receiving 'fuel from the lower end of the chamber, means for ejecting a stream of bubblerich liquid away from the pump inlet, a deflector in said localized chamber arranged for directing said stream upwardly in the chamber to draw liquid from the pond into the lower end of the chamber, and an impeller in said pump for pumping fully liquid material through the inlet and out of the chamber.

- EWALD J. KIMM.

- BERNARD R. BELLMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date

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