US2942612A - Liquid storage tank - Google Patents

Description

June 28, 1960 w. c. KLANK, JR 2,942,612

LIQUID STORAGE TANK Filed May 21, 1959 ma/0 our 5 INV ENT OR. wm 75@ c #Mw/q me United States Patent LIQUID STORAGE TANK Walter C. Klank, Jr., Dayton, Ohio, assignor to United Aircraft Products, Inc., Dayton, Ohio, a corporation of Ohio Filed May 21, 1959, Ser. No. 814,885

6 Claims. (Cl. 137-43) This invention relates to tanks storing a liquid and useful in vehicles such as aircraft wherein the tank assumes varying attitudes relative to the earths surface in correspondence with the movements of the aircraft. While not so limited, the invention has especial applica- .tion to oil supply systems in aircraft wherein an oil is taken from the tank to a place of use and then returned to the tank for storage and subsequent reuse.

In tanks and systems as described, the oil returning to the tank is accompanied by relatively large amounts of air. lt is a design objective to provide for the rapid and eicient release of such air from the tank.

A general object of the invention is to provide a new vent system in a tank as described particularly characterized by means restricting the escape of liquid from the tank by way of the vent system in and during movement to changing tank attitudes, including a roll.

Another object of the invention is to present a new vent valve for use in tanks as described characterized by means restricting an escape of liquid through the vent system not only in inverted flight and under conditions of negative gravity but also in a -roll attitude of predetermined direction and extent.

Other objects and structural details of the invention will appear from the following description when read in connection with the accompanying drawings, wherein:

Fig. l is a diagram of a tank having a vent system in accordance with the illustrated embodiment of the invention;

Fig. 2 is a View, partly diagrammatic, showing a dual valve comprised in the vent system as itV appears in a level flight attitude;

Fig. 3 is a view like Fig. 2 showing the valve as it appears in a 90 roll flight attitude, the roll being in a counterclockwise direction from level attitude;

Fig. 4 is a View like Figs. 2 and 3 showing the valve as it appears under conditions of, negative gravity, the valve also assuming this position in inverted ight; and

Fig. 5 is a view like Figs. 2 to 4 showing the valve as it appears in a clockwise direction 90 roll.

Referring to the drawings, the tank and the liquid and vent systems associated therewith area shown in the main in diagrammatic form, the invention having particular reference as noted to a dual valveY mechanism in the vent system and to the manner in which such valve atects venting in the tank.

Thus, a liquid storage tank in accordance with the illustrated embodiment of the invention comprises a tank shell having a liquid inlet 11, a liquid outlet 12 and a vent or air outlet 13. The liquid inlet is, in tanks of the present class, selectively located and arranged in cooperation with other elements of the tank to admit the returning liquid to the tank in a manner to promote the release of entrained air and to avoid turbulence. In the present instance, the lreturning liquid is admitted to the lower end of a compartment 14 within the tank. The

mixture of liquid and air rises in the compartment 14 andl spills out over the open upper end thereof, the period of containment within the compartment providing a dwell period in which the air tends effectively to separate from the liquid. Upon discharge over the upper end of the compartment, therefore, the liquid spills over the upper edge into the main body of contained liquid while the air continues to rise, moving into the upper part of the tank above the liquid level. The liquid outlet 12 may be suitably located -for discharge of the liquid and in some instances is associated with means to insure a continuing supply of liquid in dierent flight attitudes. In the present instance the location of the outlet 12 is in what may be considered to be the normal lower portion of the tank in that its location is at the bottom of the tank when the tank is in a normal, level, ight attitude. It is thus continuously supplied with liquid in most flight attitudes.

The vent outlet 13 is in the normal upper portion of the tank, having regard to normal flight attitudes. The outlet 13 is a part of a Vent system further including a chamber 15 which communicates with the outlet 13 and is defined by a wall 16 serving essentially to exclude the chamber 15 from communication with the main interior of the tank 10. Communicating freely with the vent chamber 15 is one end of a tube 17 extending toward the lower part of the tank shell and communicating therewith at its opposite end. Other tubes 1S and 19 are disposed within the vent chamber 15 and have Itheir one ends opening through the wall 16 to comunicate with the interior of the tank in the upper portion thereof at opposite ends of the vent chamber, as indicated. At their opposite ends the tubes A18 and 19 communicate with the interior of the vent chamber 15 through a valve 21 in a manner to be more particularly described. The several tubes 17, 18 and 19 are formed in circuitous fashion to obviate the entrapment of liquid therein as the tank moves from one attitude to another and the consequent slugging or discharge of the trapped oil into the vent chamber 15. Such liquid as may be admitted to the vent chamber may escape therefrom, however, by way of the tube 17 when the tank returns to a normal flight attitude. The venting arrangement, it will be understood, is one to vent the interior of the tank in varying tank attitudes and under Varying conditions. The tubes 18 and 19 vent the upper portion of the tank continuously in normal Hight attitudes and in longitudinally tilted positions corresponding to climbing and diving attitudes. Tube 17 Vents the tank under inverted ight conditions and inverted like conditions wherein the contained liquid moves to the normal upper part of the tank in response to the application of negative gravity forces, or to inverted ilight.

Referring now to Figs. 2 to 5, the valve 21 includes a fabricated body 22 wherein a transverse partition 23 divides the interior of the body essentially into compartments 24 and 25. In what may be considered to be the upper surface of the body 22 is an opening 26 cornmunicating the compartment 25 with the chamberV 15. The sides of the valve body are adapted, in a manner not fully shown herein, to receive the adjacent ends ofl the tubes 18 and 19, the latter being disposed to communicate with body chamber 24. An opening 27 in the partition wall 23 intercommunicates the compartments 24 and 25. Within the compartment 24 is a frusto-conical cage 28, the frustrum thereof terminating in thewall 23 in surrounding relation to the opening 27. There is similarly provided in the compartment 25 a frustoconical cage 29 terminating at its frustrum in the upper wall of body 22 in surrounding relation to the opening 26. The arrangement is one to place the cages 2S and 29 at right angles to one another. flight attitude, illustrated in Fig. 2, the cage 28 is hori- In a normal, level` zontally disposed While the cage 29 is vertically disposed. Within the cages are respective freely rolling balls 31 and 32 of a size to seat in and close the respective openings27 'and 26. t

As shown in Fig. 2, in anormal flight attitude the balls 31 and 32 botlroccupy positions removed from the openings 26 and 27. Ball 32, under the inuence of gravity, lies in the bottom or base of the cage 29. Ball- 31, underY the combined influences of gravity and the inclination of the side wall Vof cage 28, Vlies also at the bottom of the cage and in a position of rest on the side wall thereof. Under these conditions, therefore, a free movement of air from the tubes 18 and 19 to the vent chamber by way of compartment 24, opening 27, compartment 25 and opening 26 is permitted. In the event of aV 90"V roll to the left or in a counter-clockwise direction, however, the ball Sp1-rides up the wall of the cage 28 and comes to rest Within the opening 27, effectivelyclosing such opening. The compartment-24 is thereby cut off from communication with the compartment 25 so that the tubes 18 and 19 are disconnected from the vent chamber 15. LiquidV which might enter Vthe-vent chamber -under these conditions by virtue of flooding of the outer open ends of the tubes 18 and 19 accordingly is denied entrance. Ba1l32 remains in the bottom of the cage resting against one side wall thereof.

Fig. 4 illustrates ,the position of the balls 31 and 32 underV the iniluence of negative gravity forces or in an inverted ight attitude. Under the conditions then applyingY the ball 32 moves to the fmstrum of the cage 29 Yand seatsin opening 26. Communication of the tubes 18 and 19 with the vent chamber 15 thus is precluded as in tlierollV attitude of Fig.v 3. Fig. 5 illustrates the 90 rollin the opposite direction wherein as seen no interruption of communication between the tubes 18 and 19 and the vent chamber 15 is contemplated. It will be understood, however, thatY communication could Vunder these conditions be discontinued also ify desired, as by interposing between the cages 28 and 29 a further cage and ball, the cage being aligned with the cage 28 but inversely arranged. t 'p Figs. 2 through 5 are, as herefore noted, partly diagrammatic. The diagrammatic manner of execution is directed Vprimarily toward a clear showing of the manp ner in Ywhich compartment 2'4 of valve assembly 2 1 communicates with Vadjacent ends of pipes 18 and 19. Y True vertical longitudinal sections through-the valve assembly would remove one of thepipes-18 or 19 from view entirely and ywould partly obscure therother by reason of the presence of Aball' 31. Accordingly, for purposes Y ofl clarity and simplicity, in Figs. 2 through 5 the pipes to pass admitted air out of the tank from the normal upper portion thereof; and a pair of normally open gravity operated valves in said vent line, one closing said Yline under conditions of inverted tankattitude and under conditions of negative gravity,`and the other closing said line under conditions'ofv a roll attitude of predetermined direction and extent. f

2.*A liquid storage'tank'which in-use assumes diifer-V ent attitudes vrelative to the earths surface and which includes outlet and inlet connections, the latter admitting-to the tank a liquid-air mixturegfincluding a vent linelto pass admitted Vair out of `the Vtank from the normal upper Vportion thereof; and alpair of normally open under conditions of negative gravity,fand the other closing said line under conditions of a roll attitude of predetermined direction and extent.

3. A liquid storage tank which in use assumes diterent attitudes relative to the earths surface and which includes outlet and inletA qnuections, the latter admitting to the tank a liquid-air mixture; including a vent chamber in said tank communicatingY with the tank exteriorgpvent tubes communicatingat their one ends with different portions ofthe tank interior and'cterminating at their opposite endsl in said vent chamber, atleast one of said vent tubes communicating at its said one end with the normal .upper portion o f the tank interior; and valve means controlling the communication of said one Vtube with said vent chamber, said means closing said tube from communication with the vent chamber under conditions ofl inverted tank attitude 'and under conditions of negative gravity vand also under conditions of a. roll attitudeV of Ypredetermineddirection and extent, said valve means comprising a'pair of independently .operable series arranged valves,h one responding to negative gravity forces and toY movement of the tank to inverted attitude and the other responding to a tank roll.

4. A liquid storage tank which in use assumes different attitudes relative to the earths surface and which includes outlet and inlet connections, thel latter admitting Y to the tank a liquid-air mixture; including `a vent cham- Y ber in said tank communicating with the'tank exterior;

" per portion of the tank interioryand gravity operated gravity operated valves in said vent line, one closing f said line under conditions of inverted, tank attitude and valve means controlling the communication of said one tube with saidrventpchamber, said valve means including a body providing. aV first Vcompartment communicat-Y ing with said vent chamber and a second compartment communicating with the said opposite end of said one tube and with said rst compartment, a gravity responsive valve in said rst compartmentrmov'abl'e Yto interrupt venting from said first compartment Yto said vent chamber in response ,to` negative 'gravity forces and to inversionrof the valve body, and a gravity responsive valve Vin said second' compartment movable to interrupt communication betweensaidsecond compartment and said first compartment in Vresponse to a rolling motionv of predetermined direction and extent of said body.

S. A'Vliquid storage tank which in use `assumes, diierentV attitudes relative to the earths surface and which includes outlet andinlet connections, thelatter admittingv to theV tank a liquid and large amounts of air; including a vent chamber in said' tank communicating with thetankext'erior; lvent tubes reaching at theirone' ends into opposite ends of the tankin the` normal .upper portion thereof to vent said upper portion inr normal and forward and rearward tilted attitudes of the tank, the opposite ends of said tubes terminating in said vent chamber, a valve Y body through which said.. opposite ends of said tubes communicate with-said vent chamber, said valve body providing a first compartment communicating with Vsaid tubes ,and a second compartment Ycommunicating with the-vent chamber and an opening intercommunicating said rst and second compartments, a freely rolling `ball in said first compartment movable in response to a lateral tilt or roll of `the tank of a'predetermined extent in one direction to close said opening intercommunicating said rst and second compartments, and another ball freely rolling'in said second chamber ,and movable toclose said second compartment from V,con'nnunication with saidyent chamber Vunder the influence ofrnegative gravity forces and in response toA inversionV of the tank. p Y Y t 6. A liquid storage tank according toV laim 5, characten'zed'inthat said first Ycompartment. of .said .valve body isforrmed with inclined walls to causesaid ball therein References Cited in the le of this patent UNITED STATES PATENTS Flanders Apr. 25, 1916 Zoder Mar. 19, 1940 Gregory Mar. 7, 1944 Stewart Dec. 18, 1956 Carroll July 30, 1957 Eshbaugh Feb. 24, 1959 Simcock June 9, 1959

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