US3843024A - Liquid expulsion subsystem having orientation responsive pump - Google Patents

Abstract

A subsystem which permits the temporary continued flow of a liquid (such as a fuel) from a tank, even during periods when, due to the physical orientation of the tank (such as when the tank is, for example, tilted or is in an inverted position), the flow of the liquid would ordinarily stop completely, because the liquid uncovers the outlet of the tank, or the liquid otherwise ''''runs away'''' from the outlet. The subsystem, as adapted for use with hydrazine in a propellant feed system, includes: a tank containing hydrazine and having an outlet in the lower portion thereof; a source of gas under high pressure connected to the tank; and, an expulsion assembly positioned in the lower portion of the tank, and above the outlet of the tank. The expulsion assembly has cooperating elements, including a diaphragm of flexible material, preferably plastic, which together with the walls of the tank form, define, and limit a ''''trapping chamber'''' part of the lower portion of the tank. When the tank is in its usual, and normal, bottom-down position, the expulsion assembly permits normal gravitational flow of the hydrazine from the entire tank. When the tank is in an orientation which would ordinarily result in the discontinuance of flow of the hydrazine therefrom, the expulsion assembly permits the continued temporary flow of the hydrazine by expelling that volume of hydrazine which is located within (and is ''''trapped'''' in) the ''''trapping chamber'''' part of the tank and is under the flexible plastic diaphragm.

Description

United States Patent Barber [14 11 3,843,024 [4 11 Oct. 22, 1974 LIQUID EXPULSION SUBSYSTEM HAVING 1 ORIENTATION RESPONSIVE PUMP [75] Inventor: Hartley E. Barber, Sylmar, Calif.

[73] Assignee: The United States of America as represented by the Secretary of the Air Force, Washington, DC. 1

[221 Filed: Oct. 26, 1972 [21] Appl. No.: 301,029

[52] US. Cl 222/207, 222/386.5, 417/118 [51] Int. Cl B67d 47/34 [58] Field of Search 222/207, 209, 386.5;

[56] References Cited UNITED STATES PATENTS 6/1963 Barnes ZZZ/386.5 x 2/1966 Christian et al. 222/207 x Primary ExaminerRobert B; Reeves Assistant Examiner-David A. Scherbel Attorney, Agent, or Firm -l-larry A. Herbert, Jr.; Arsen Tashijian ing periods when, due to the physical orientation of the tank (such as when the tank is, for example, tilted or is in an inverted position), the flow of the liquid would ordinarily stop completely, because the liquid uncovers the outlet of the tank, or the liquid otherwise runs away" from the outlet. The subsystem, as adapted for use with hydrazine in a propellant feed system, includes: a tank containing hydrazine and having an outlet in the lower portion thereof; a source of gas under high pressure connected to the tank; and, an expulsion assembly positioned in the lower portion of the tank, and above the outlet of the tank. The expulsion assembly has cooperating elements, including a diaphragm of flexible material, preferably plastic, which together with the walls of the tank form, define, and limit a trapping chamber part'of theflower portion of the tank. When the tank is in its usual, and normal, bottom-down position, the expulsion'assembly permits normal gravitational flow of the hydrazine from the entire tank. When the tank is in an orientation which would ordinarily result in the discontinuance of flow of the hydrazine therefrom, the expulsion assembly permits the continued temporary flow of the hydrazine by expelling that volume of hydrazine which is located within (and istrapped" in) the .trapping chamber part of the tank and isunder the flexible plastic diaphragm.

3 Claims, 2 Drawing Figures PAlimmnmzzrsu ww mm mSSOm mqmu LIQUID EXPULSION SUBSYSTEM HAVING ORIENTATION RESPONSIVE PUMP BACKGROUND OF THE INVENTION aptation described herein of my invention is by way of illustration only, and is not by way of any limitation.

In some propellant feed systems, such as those for use in aerospace applications (e.g., use in spacecraft, aircraft, missiles, and the like), it often happens that, during in-flight maneuvering within the planetary gravitational field, the liquid propellant reservoir, such as a tank, is physically reoriented from its usual and normal bottom-down position to a tilted, or even to an inverted, position. As a result, the flowof the liquid, whether it be a monopropellant or in the case of a bipropellant, the liquid fuel or the liquid oxidizer thereof, will discontinue (i.e., stop completely), because the liquid in the reservoir uncovers, or runsaway from, the reservoir liquid outlet, which is conventioally located in the lower portion of the reservoir, usually at the bottom thereof. The consequences of such liquid starvation are highly undesirable and, in certain situations which are readily apparent to those in the art, may be disastrous and tragic. i

There is, therefore, a constant and genuine need in the liquid supply system art and, more specifically, in the propellant feed system art for a component thereof, such as a subsystem, to assure continued flow of the liquid in the liquid propellant reservoir to the user component, such as an auxiliary power unit, irrespective of the orientation or attitude of the reservoir, even if such continued flow is only temporary (i.e., a limited time, such as 0.5 seconds).

l have invented a liquid expulsion subsystem which fullfils this need;and, therefore, I have significantly advanced the state-of-the-art.

SUMMARY OF THE INVENTION This invention pertains to a unique liquid expulsion subsystem, as adapted for use in a propellant feed system, which will permit the continued flow of the liquid within the reservoir of the subsystem, irrespective of the orientation or attitude of the reservoir.

Therefore, the principal object of this invention is to provide such a unique (and, new, useful and unobvious) liquid expulsion subsystem.

Another object of this invention is to provide such a liquid expulsion subsystem which, in addition to its unique fundamental functional features, is also simple in structure and, therefore, is economical to manufacture, and further is completely reliable and, therefore, is fool proof.and fail safe in operation.

These objects, and other equally important and related objects, of this invention will become readily apparent after a consideration of the description of the invention and reference to the drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view, in simplified schematic form, partially in cross section and partially fragmented, of a preferred embodiment of my inventive I 2 subsystem, as adapted for use in a propellant feed system, and with FIG. 1 also showing therein in phantom the position of one component of my inventive subsystem immediately after the completion of the expulsion action;

FIG. 2 is a side elevation view, in simplified schematic form, in cross section, enlarged, in detail, and not to scale, of a selected portion of my inventive subsystem.

DESCRIPTION OF THE PREFERRE EMBODIMENT With reference to FIG. 1, therein is shown, in a side elevation view, in simplified schematic form, partially in cross section and partially fragmented, a preferred embodiment of my invention, as adapted for use in a propellant feed system.

The preferred embodiment of my invention, the unique liquid expulsion subsystem 10 as shown in FIG. 1, is for'use in a propellant feed system wherein hydrazine is the liquid fuel, and the liquid expulsion subsystem 10 is for use in expelling, or continuing the flow of, the hydrazine.

The liquid expulsion subsystem 10 includes: a reservoir or tank 11 of liquid-impervious (i.e., in this case,

hydrazine-impervious) material, and tank 11 has a top surface 12, a bottom surface 13, and internal surface 14, an upper portion 15, a lower portion 16, a first inlet 17, a second inlet 18, and an outlet 19 located in the lower portion 16 of tank 11; a source 20 of gas 21 under high pressure (e.g., 45 psi), with source 20 having an outlet 22; a first hollow conduit 30 which has two ends 31 and 32, with one end 31 connected to the outlet 22 of the gas source 20, and with the other end 32 connected to the second inlet 18 of tank 11; valving means, such as valve 33, disposed between the outlet of the source 20 of gas'2l and the: second inlet of tank 11 and connected to first hollow conduit 30, for controlling the flow of gas 21 from source 20, through first conduit 30, and into tank 11; and, a liquid expulsion assembly 40 which is positioned within the lower portion 16 0f tank 11 and above outlet 19 of said tank 11.

Liquid expulsion assembly 40 comprises: a lip seal ring 50 which has a lip" or mating surface 51 (also referred to herein as the sealing surface), and which has a periphery S2, and also which is positioned with the periphery 52 abutting with, and sealingly attached (i.e., in sealing contact) by suitable means to, the internal surface 14 of tank 11 so as to permit movement of the ring 60 with respect to the surface 51; a perforated ring 60 which has perforations, such as 61 and 62, and

which has a periphery 63, and which is positioned so that it 60 is below of, and essentially parallel to lip seal ring 50, with the periphery 63 abutting with, and sealingly attached (i.e., in sealing contact) by suitable means to, the internal surface 14 of tank 11 so as to permit movement of the ring 60 with respect to the surface 51 of the ring 50; a rigid seal ring (hereinafter referred to as the seal ring) which is smaller in size than perforated ring 60, and which has an inner periphery 7 1, and an upper surface 72, and which is disposed between perforated ring 60 and lip seal ring 50, and which abuts with, and is attached by suitable means to, the perforated ring 60; a flexible diaphragm 80, preferably made of plastic, which said diaphragm has an upper surface 81, a lower surface 82, a periphery 83, and a centrally located opening 84, such as a pinhole,

with the diaphragm so positioned that the periphery 83 is abutting with, and is attached by suitable means to, the seal ring 70 at the inner peripheral surface 71 of the ring 70; and, a float ring 90 which is attached to the upper surface 81 of the diaphragm 80 and which surrounds the central opening (or pinhole) 84 of the diaphragm 80.

Also shown in FIG. 1 are: second hollow conduit 34 which has-two ends, with one end 35 connected to first inlet 17 of tank 11, and with the other end not shown in the interest of maintaining simplicity of the drawing; and, means for closing inlet 17, such as valve 36 which is disposed between inlet 17 and a source of hydrazine (which source also is not shown to maintain simplicity), and which said valve 36 is connected to second hollow conduit 34.

It is here to be noted: that valve 33 also, in effect, closes and opens second inlet 18; that valve 36 also controls the flow of hydrazine (or other liquid used), with the flow thereof shown in FIG. 1 by arrows having reference numeral 100; that the above reference to seal ring 70 as being rigid is intended only as a comparative term, in the sense that the diaphragm 80 (which is attached to the ring 70) is flexible; that seal ring 70 has an effective density slightly greater than the liquid in the tank 11 (e.g., if hydrazine is the liquid in the tank and is assumed, to have a density of 1.0, then thepreferred density of the seal ring is about 1.3); that upper surface 72 of ring 70 is directly opposed (i.e., is directionally opposite) to the lip or mating surface (or sealing surface) 51 of lip seal ring 50; and, that the liquid expulsion assembly40, as a whole, together with the internal surface 41 (or sidewalls, if any) of the reservoir or tank 11, form, define, and limit a trapping chamber part, generally designated as 16A, of the lower portion 16 of tank 11.

It is also here to be noted that a selected portion of the liquid expulsion assembly 40 of my invention is generally designated A" in FIG. 1; is shown in FIG. 2; and, will be discussed hereinafter.

With reference to FIG. 2, therein is shown, in a side elevation view, insimplified schematic form, in cross section, in detail, enlarged, and not to scale, a portion of the liquid expulsion assembly 40 of my inventive liquid expulsion subsystem 10, as adapted for use in a propellant feed system, which said portion is designated as A both in FIGS. 1 and 2.

More specifically, shown in FIG. 2 are: lip seal ring 50 with lip or sealing surface 51; seal ring 70 with inner periphery 71 and with upper surface 72; and, flexible diaphragm 80.

MODE OF OPERATION OF THE PREFERRED EMBODIMENT The mode of operation of my inventive subsystem 10, and of the liquid expulsion assembly 40, thereof, is selfevident and is easily understood from the foregoing description, coupled with reference to the drawings.

As a preliminary matter, it is to be remembered that the preferred embodiment 10, FIG. I, is an adaptation for use in a propellant feed system wherein my liquid expulsion subsystem 10 is for use in expelling, and in continuing the flow of, hydrazine (a liquid or one of the liquids used) in the propellant system.

It is to be assumed that, at this point, the tank 11 is in its normal, bottom-down position.

The liquid, i.e., the hydrazine, is introduced into the tank 11 by suitable means, such as from a source of hydrazine which is connected t conduit 34. With the valve 36 in an open mode e hydrazine 100 flows through conduit 34, through first inlet 17 (which is, in effect, closeable by positioning valve 36 in the closed mode), and into tank 11 to the desired height or level, or in the desired quantity. First inlet 17 is then closed by closing valve 36, and the inflow of the hydrazine 100 ceases.

Duringthis filling process, the hydrazine also goes to the lower portion 16 of the tank 11, including the trapping chamber" part 16A, by flowing around the diaphragm 80, past the lip 51 of lip seal ring 50, over the upper surface 72 of seal ring 70, and through the perforations, such as 61 and 62, of perforated ring 60. The tank 11 is pressurized, and the hydrazine 100 is kept under pressure, by use of gas pressure source 20, gas 21 flowing therefrom, conduit 30, valve 33, and second outlet 18 of tank 11. The pressure exerted is preferably approximately 45 psi. At this time the diaphragm is in the float position shown in FIG. 1, with the float ring providing buoyancy. Additionally, at this time, the gravitational force is a positive 1.0 $60.,

Upon demand, and by the use of suitable means, the hydrazine flows through outlet 19 of tank 11 to the user component, such as an auxiliary power unit, because of the gravitational force and the pressure erted upon the hydrazine 100.

.When, however, the tank is reoriented from its normal bottomdown attitude, such as when the tank is inverted, and as a result there is reverse or negative G" loading, the flow of the hydrazine 100 (which would ordinarily stop completely, because the hydrazine 100 uncovers the outlet 19) continues, due to the unique structure of my invention 10. I

What sequentially, and physically, occurs is that, with the reverse G loading, the seal ring 70 falls (i.e., rises in the bottom-down attitude shown in FIGS. 1 and 2) and the upper surface thereof 72 sealingly rests against (and mates with) the lip 51 of lip seal ring 50, primarily due to the hydraulic pressure of the hydrazine 100. A volumetric amount of hydrazine 100 is, thereby, trapped in trapping chamber 16A. Bubbles, if any, escape through central opening 84 of diaphragm 80. The tank pressure, discussed hereinabove, is felt by and on the diaphragm 80, but is not felt by and on the seal ring 70, which is temporarily resting against the lip seal ring 50. Positive expulsion of the hydrazine 100 trapped in trapping chamber 16A continues through outlet 19 because of the gas pressure-related collapse of flexible diaphragm 80, as shown by the phantom line in FIG. 1, through its 80 displacement volume, into trapping chamber 16A. This displacement volume is generallydesignated as B in FIG. 2; and, said volume is represented two-dimensionally in said FIG. 2 by the area bounded by the curved line 84 identifying the diaphragm in the float position, and by the curved phantom line in said Figure which represents the collapsed position of the diaphragm 80 immediately after the completion of the positive expulsion action.

As can be easily seen, the flow of the hydrazine 100 will continue temporarily for the needed or desired time, and the highly undesirable propellant starvation will be prevented.

It can also be easily seen that the diaphragm displace- CONCLUSlON It is clearly evident from the above description, and from the drawings herein, that all of the objects of this invention have been attained. Therefore, it is not believed necessary to again set forth the objects, and the other objects related thereto, of the invention, and show how each of the objects has been achieved by, and with the use of, the invention. Suffice it to say that, in addition to its fundamental inventive structural features, the invention is simple, economical to manufacture, completely reliable, and foolproof and fail safe."

In addition, while there have been shown and described the fundamental features of my invention, as adapted for a specific use and as applied to a particular preferred embodiment, it is to be understood that various other adaptations, embodiments, substitutions, omissions, additions, and the like, can be made by those of ordinary skill in the art without departing from the spirit of my invention. In essence, my liquid expulsion subsystem, and particularly my liquid expulsion assembly thereof, can be used, or can be adapted to be used, to provide positive expulsion of any liquid from a reservoir under adverse .G conditions within a planetary gravitational field.

What is claimed is:

1. A liquid expulsion subsystem, comprising:

a. a tank made of liquid-impervious material, for containing a liquid which is to be expelled from said tank, wherein said tank includes a top surface, a bottom surface, and an internal surface, and with said tank having therein an upper portion and a lower portion, and also with said tank having a first closeable inlet to permit the inflow of the liquid into the tank, a second inlet, and an outlet to permit the outflow of the liquid from the tank, with said outlet located in the said lower portion of the tank;

b. a source of gas under high pressure, with said surface having an outlet;

c. a first hollow conduit having two ends, with one end connected to the outlet of said source of gas under high pressure, and with the other end connected to the second inlet of said tank;

d. valving means, disposed between the outlet of said source of gas under high pressure and the second inlet of said tank, and connected to said first hollow conduit, for controlling the flow of the gas from said gas source, through said first hollow conduit, and into said tank;

e. and, a liquid expulsion assembly, positioned within the said lower portion of said tank and above said outlet of said tank, comprising:

1. a lip seal ring having a periphery, with said periphery abutting with, and sealingly attached by suitable means to, the internal surface of said tank;

2. a perforated ring havinga periphery and positioned below of, and essentially parallel to, said lip seal ring, with said periphery abutting with, and sealingly attached by suitable means to, the internal surface of said tank;

3. a seal ring, smaller in size than said perforated ring, and having an inner peripheral surface, with said seal ring disposed between said perforated ring and said lip seal ring, and with said seal ring abutting with, and attached to, said perforated r1ng;

4. a flexible diaphragm having an upper surface, a

lower surface, a periphery, anda centrally located opening, with said periphery abutting with, and attached by suitable means to, the inner peripheral surface of said-seal ring;

5. and, a float ring attached to the upper surface of said diaphragm and surrounding said central opening of said diaphragm.

2. The liquid expulsion subsystem, as set forth in claim 1, wherein said flexible diaphragm of said liquid expulsion assembly is made of plastic.

3. The liquid expulsion subsystem, as set forth in claim 1, wherein the effective density of said seal ring of said liquid expulsion assembly is of an effective density slightly greater than the liquid to be contained by,

and in, said tank.

Claims (7)

1. A liquid expulsion subsystem, comprising: a. a tank made of liquid-impervious material, for containing a liquid which is to be expelled from said tank, wherein said tank includes a top surface, a bottom surface, and an internal surface, and with said tank having therein an upper portion and a lower portion, and also with said tank having a first closeable inlet to permit the inflow of the liquid into the tank, a second inlet, and an outlet to permit the outflow of the liquid from the tank, with said outlet located in the said lower portion of the tank; b. a source of gas under high pressure, with said surface having an outlet; c. a first hollow conduit having two ends, with one end connected to the outlet of said source of gas under high pressure, and with the other end connected to the second inlet of said tank; d. valving means, disposed between the outlet of said source of gas under high pressure and the second inlet of said tank, and connected to said first hollow conduit, for controlling the flow of the gas from said gas source, through said first hollow conduit, and into said tank; e. and, a liquid expulsion assembly, positioned within the said lower portion of said tank and above said outlet of said tank, comprising: 1. a lip seal ring having a periphery, with said periphery abutting with, and sealingly attached by suitable means to, the internal surface of said tank; 2. a perforated ring having a periphery and positioned below of, and essentially parallel to, said lip seal ring, with said periphery abutting with, and sealingly attached by suitable means to, the internal surface of said tank; 3. a seal ring, smaller in size than said perforated ring, and having an inner peripheral surface, with said seal ring disposed between said perforated ring and said lip seal ring, and with said seal ring abutting with, and attached to, said perforated ring; 4. a flexible diaphragm having an upper surface, a lower surface, a periphery, and a centrally located opening, with said periphery abutting with, and attached by suitable means to, the inner peripheral surface of said seal ring; 5. and, a float ring attached to the upper surface of said diaphragm and surrounding said central opening of said diaphragm.

2. a perforated ring having a periphery and positioned below of, and essentially parallel to, said lip seal ring, with said periphery abutting with, and sealingly attached by suitable means to, the internal surface of said tank;

2. The liquid expulsion subsystem, as set forth in claim 1, wherein said flexible diaphragm of said liquid expulsion assembly is made of plastic.

3. The liquid expulsion subsystem, as set forth in claim 1, wherein the effective density of said seal ring of said liquid expulsion assembly is of an effective density slightly greater than the liquid to be contained by, and in, said tank.

3. a seal ring, smaller in size than said perforated ring, and having an inner peripheral surface, with said seal ring disposed between said perforated ring and said lip seal ring, and with said seal ring abutting with, and attached to, said perforated ring;

4. a flexible diaphragm having an upper surface, a lower surface, a periphery, and a centrally located opening, with said periphery abutting with, and attached by suitable means to, the inner peripheral surface of said seal ring;

5. and, a float ring attached to the upper surface of said diaphragm and surrounding said central opening of said diaphragm.

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