JP2009293525A - Filter device for propellant tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter device for a propellant tank capable of positively removing dust included in a propellant and supplying the propellant downward, and avoiding intrusion of air bubbles rising from below and positively letting the air bubbles escape upward, to thereby prevent deterioration of engine performance caused by the air bubbles and dust. <P>SOLUTION: This filter device is equipped with a filter plate 12, a hollow vent port 14, and a substantially horizontal vortex preventive plate 16. The filter plate 12 has its outer edge part fixed water-tightly to a tank lower part above an upper edge opening of a propellant supply pipe 5 and includes a filter 12a at the center for removing the dust in the propellant, and a through-hole 12c penetrating a portion of the filter 12a. The vent port 14 has its lower end water-tightly attached to the through-hole 12c, is extended substantially vertically upward, and has its upper end positioned at a prescribed height from the upper face of the filter 12a. The vortex preventive plate 16 is positioned above the vent port 14, spaced apart therefrom, and covers the entire face of the filter 12a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a propellant tank filter device that discharges propellant in a tank by a pressurized gas or a pump and supplies the propellant downward through a propellant supply pipe.

  The propellant tank is a propellant tank that discharges propellant (liquid propellant, liquid fuel, liquid oxidant, etc.) in the tank with pressurized gas or pump and supplies it to the engine or thruster via piping. Say. Hereinafter, in this application, propellant means liquid propellant, liquid fuel, liquid oxidant, and the like.

In a rocket engine using a propellant tank, a filter is generally attached to the discharge port of the tank holding the propellant so as not to supply dust to the downstream rocket engine.
Also, especially when a filter is installed at the bottom of the tank, bubbles generated in the lower pipe rise and are captured by the filter, and when propellant flows, the bubbles flow into the rocket engine, reducing performance. Or there is a risk of damage.
Therefore, it is necessary to efficiently remove bubbles in the propellant.

  In order to remove bubbles in the liquid, for example, the means of Patent Documents 1 and 2 have already been proposed.

Patent Document 1 aims to effectively separate and remove only bubbles mixed in a liquid in a microgravity environment.
Therefore, the apparatus of Patent Document 1 is connected to a thermal control system loop used in a microgravity environment such as outer space, and is used for a microgravity environment for removing bubbles mixed in the liquid of the thermal control system loop. In the bubble removing device, as shown in FIG. 3, the gas-liquid mixed liquid in the thermal control system loop is introduced into the end of the barrel-shaped cylindrical casing 57 to give a swirl flow in the tangential direction. A liquid mixed liquid introduction pipe 58 is connected, and a hydrophobic hollow fiber membrane pipe 51 is provided along the length direction of the cylindrical casing 57 in the axial center portion so as to suck the separated gas. The front end of the hollow fiber membrane tube 51 is closed and suction means is provided at the rear end.

Patent Document 2 aims to reliably separate bubbles from a liquid in a container and take out only the liquid.
Therefore, as shown in FIG. 4, when the liquid 63 is supplied between the gradient electric field generating electrodes 61 and 62 having different polarities, the apparatus of Patent Document 2 generates the gradient generated between the gradient electric field generating electrodes 61 and 62. The bubbles 65 mixed in the liquid 63 in the fluid container are dielectrically polarized by the electric field 64, and the dielectrophoretic force acts on the dielectrically polarized bubbles 65, so that the bubbles 65 are moved to the weak electric field portion side, and the liquid 63. Therefore, the gas is discharged to the outside from the gas discharge port provided on the weak electric field portion 66 side, and the bubble removing liquid is discharged to the outside from the liquid discharge port provided on the strong electric field portion 67 side. .

Japanese Patent Laid-Open No. 6-210106, “Bubble Removal Device for Microgravity Environment” Japanese Patent Laid-Open No. 6-262005, “Bubble Removal Device”

FIG. 5 is an example of a configuration diagram of a filter device for a conventional propellant tank, in which (A) is a longitudinal sectional view of the lower portion of the tank, and (B) is a view taken along the line BB.
In FIG. 5A, 71 is a propellant in the tank, 72 is a pressurized gas sealed or supplied in the tank, 73 is a propellant tank, 74 is a propellant take-out portion, and 75 is a propellant to the rocket engine. A supply pipe, 76 is a vortex prevention plate, 77 is a filter device, and 78 is a filter mounting ring.
The vortex prevention plate 76 has a function of preventing the generation of vortices around the supply pipe 75 when the liquid level of the propellant 71 is low.

As shown in FIG. 5B, the filter device 77 is a disk-shaped member having an opening at the center, a filter 77 a is attached to the center, and an outer edge is attached in close contact with the filter attachment ring 78. The filter 77a is made of a mesh having a small opening size and has a function of removing dust in the propellant passing through the mesh.
A plurality of gas vent holes 77b are provided in the outer peripheral portion of the filter device 77, and the air bubbles trapped in the filter through these holes have a function of releasing upward.

  However, in the conventional filter device described above, it is inevitable that a part of the propellant passes through the vent hole, and the dust contained in this liquid is supplied to the rocket engine, which deteriorates the performance of the engine or damages it. There was a risk of giving.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to reliably remove the dust contained in the propellant and supply it downward, and to prevent the bubbles rising from below from escaping and reliably escape upward. Another object of the present invention is to provide a filter device for a propellant tank that can prevent a decrease in filter performance due to the retention of bubbles and a decrease in engine performance due to bubbles and dust.

According to the present invention, it has a tank that holds propellant inside and a propellant supply pipe that extends downward from the lower part of the tank, and the propellant in the tank is discharged by pressurized gas or a pump, A filter device for a propellant tank to be supplied downward through a pipe,
The outer edge is fixed to the tank lower part above the upper end opening of the propellant supply pipe in a watertight manner, and has a filter for removing dust in the propellant at the center, and a through-hole penetrating through this part of the filter A filter plate having
A hollow cylindrical vent port whose lower end is attached to the through hole in a watertight manner, extends substantially vertically upward, and whose upper end is positioned horizontally at a predetermined height from the upper surface of the filter,
There is provided a propellant tank filter device comprising a substantially horizontal vortex prevention plate located above the vent port with a predetermined gap and covering the entire filter surface.

  According to a preferred embodiment of the present invention, the predetermined height of the vent port is set so that the static pressure of the propellant from the upper surface of the filter to the horizontal upper end is larger than the passage resistance of the filter.

  Further, the inner diameter of the vent port is set to a size such that an upward flow of propellant is formed by bubbles rising inside.

  Further, the predetermined gap of the vortex preventing plate is set so that the pressure loss of the propellant passing therethrough is larger than the passage resistance of the filter.

According to the configuration of the present invention, the horizontal upper end of the hollow cylindrical vent port has a predetermined height from the upper surface of the filter (for example, the static pressure of the propellant from the upper surface of the filter to the upper end is larger than the passage resistance of the filter). Therefore, no propellant flow toward the vent port is generated, and no propellant passing through the vent port is generated.
Accordingly, since all of the propellant supplied downward passes through the filter, dust contained in the propellant can be reliably removed and supplied downward.
In addition, the lower end of the hollow cylindrical vent port is watertightly attached to the through hole of the filter and extends almost vertically upward so that air bubbles rising from below and trapped by the filter can be prevented from entering the dust through the vent port. Can be surely escaped upward.
Therefore, it is possible to prevent a decrease in engine performance due to bubbles and dust.

  Further, by setting the inner diameter of the vent port to such a size that an upward flow of the propellant is formed by the bubbles rising inside, the inflow of the propellant from the upper end of the vent port can be further prevented.

  In addition, by setting the gap between the vortex prevention plate vent port and the horizontal upper end of the vent port so that the pressure loss of the propellant passing therethrough is greater than the passage resistance of the filter, the propellant from the upper end of the vent port Can be further prevented.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a schematic diagram of a rocket propulsion system provided with the filter device of the present invention.
In this figure, 2A is a fuel tank, 2B is an oxidizer tank, 3 is a rocket engine, 4 is a valve (flow control valve), and the propellant 1 in the tanks 2A and 2B is pressurized with pressurized gas, The rocket engine 3 is supplied via the supply pipe 5.

That is, the fuel tank 2 </ b> A and the oxidant tank 2 </ b> B are gas pressurized propellant tanks, and the propellant 1 (liquid fuel and liquid oxidant) in the tank is pressurized with pressurized gas and passed through the propellant supply pipe 5. Supply to the lower rocket engine 3. Hereinafter, the fuel tank 2A and the oxidant tank 2B are simply referred to as “tank 2”.
In addition, this invention is not limited to a gas pressurization type propellant tank, The pump type propellant tank which installs a pump in the middle of the propellant supply pipe 5, and discharges the propellant in a tank with a pump may be sufficient.

  The filter device 10 of the present invention is provided in a propellant extraction unit 6 provided below the tank 2. The propellant extraction part 6 is provided in the lower part of each tank 2 and is a container-shaped part with an upper opening. Even when the amount of the propellant 1 is small, the propellant extraction unit 6 stabilizes the propellant at the upper end opening of the propellant supply pipe 5 To supply.

FIG. 2 is a configuration diagram of the filter device of the present invention, and is an enlarged view of part A of FIG.
In this figure, the filter device 10 of the present invention includes a filter plate 12, a hollow cylindrical vent port 14, and a substantially horizontal vortex prevention plate 16.

The filter plate 12 has an outer edge fixed in a watertight manner to the tank lower part (in this example, the propellant extraction part 6) above the upper end opening of the propellant supply pipe 5, so that the propellant 1 does not flow downward from the outer edge. It has become.
The filter plate 12 has a filter 12a for removing dust in the propellant 1 at the center. The outside of the filter 12a is a ring 12b without a through hole. The ring 12b is not indispensable, and the entire surface may be the filter 12a as long as the outer edge portion can be fixed in a watertight manner.

The filter 12a is made of a mesh (for example, a wire net) having a smaller opening size than the dust in the propellant 1, and has a function of removing dust in the propellant passing through the mesh.
Further, the filter plate 12 has a through hole 12c penetrating through a part of the filter 12a. The position of the through hole 12c is preferably directly above the upper end opening of the propellant supply pipe 5, but may be other than that.

In this example, the filter plate 12 and the filter 12a are substantially horizontal flat plate shapes. However, the present invention is not limited to this configuration, and the filter plate 12 and the filter 12a may be formed in a shape other than a flat plate, for example, an upward convex chevron or an arc surface.
In this case, the position of the through hole 12c is preferably provided in the vicinity of the top of the chevron or the arc surface.

The hollow cylindrical vent port 14 has a lower end attached to the through hole 12c of the filter plate 12 in a watertight manner, extends substantially vertically upward, and an upper end is positioned horizontally at a predetermined height from the upper surface of the filter. Bubbles generated in the propellant supply pipe 5 rise to reach the lower end of the vent port 14 and flow into the propellant 1 through this.
In this example, the vent port 14 is a hollow taper tube whose upper part is thin, and the rising speed of the bubbles passing through the vent port 14 becomes faster as it goes upward.

The height of the vent port 14 is set so that the static pressure of the propellant 1 from the upper surface of the filter to the horizontal upper end is larger than the passage resistance of the filter 12a. With this configuration, the flow of the propellant 1 toward the upper end of the vent port 14 is not generated, and the propellant 1 that passes downward through the vent port 14 is not generated.
In addition, the inner diameter of the vent port 14 is set to a size such that an upward flow of the propellant 1 is formed by bubbles rising inside, and further prevents the propellant 1 from flowing in from the upper end of the vent port 14.

The substantially horizontal vortex prevention plate 16 has an outer peripheral portion supported by a plurality of supports 15, is located above the vent port 14 with a predetermined gap, and covers the entire filter surface.
The vortex prevention plate 16 has a function of preventing the generation of vortices around the propellant supply pipe 5 when the liquid level of the propellant 1 is low. The gap between the vortex prevention plate 16 and the horizontal upper end of the vent port 14 is set so that the pressure loss of the propellant 1 passing therethrough is larger than the passage resistance of the filter 12a.
Therefore, this configuration can further prevent the propellant 1 from flowing in from the upper end of the vent port 14.

With the above-described configuration, the bubbles generated in the propellant supply pipe 5 rise and are captured by the filter 12a or directly enter the vent port 14 and reliably enter the vent port 14 to avoid contamination. By venting, the vent port is vented.
On the other hand, since the gap between the vent port 14 and the vortex prevention mechanism (vortex prevention plate 16) is small, the pressure loss is large, and the head at the tip of the vent port is higher than the filter. No flow of 1 occurs, the propellant is not discharged from the vent port, and no dust flows from the vent port.
Therefore, the configuration of the present invention can reliably prevent the engine performance from being deteriorated due to bubbles and dust.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the gist of the present invention.

It is a schematic diagram of the rocket propulsion system provided with the filter device of the present invention. It is a block diagram of the filter apparatus of this invention. It is a schematic diagram of the apparatus of patent document 1. FIG. It is a schematic diagram of the apparatus of patent document 2. FIG. It is a block diagram of the filter apparatus of the conventional propellant tank.

Explanation of symbols

1 propellant, 2 tanks,
2A fuel tank, 2B oxidant tank,
3 rocket engines, 4 valves,
5 Propellant supply pipe, 6 Propellant extraction part,
10 filter device, 12 filter plate,
12a filter, 12b ring, 12c through hole,
14 Vent port, 16 Vortex prevention plate

Claims (4)

It has a tank that holds propellant inside, and a propellant supply pipe that extends downward from the lower part of the tank. The propellant in the tank is discharged by pressurized gas or a pump, and is lowered downward through the propellant supply pipe. A propellant tank filter device for supplying,
The outer edge portion is fixed in a watertight manner to the tank lower portion above the upper end opening of the propellant supply pipe, and has a filter for removing dust in the propellant in the central portion, and a through hole penetrating through the filter in a part of the filter A filter plate having
A hollow cylindrical vent port with a lower end attached to the through hole in a watertight manner, extending substantially vertically upward, and an upper end positioned horizontally at a predetermined height from the upper surface of the filter,
A propellant tank filter device, comprising: a substantially horizontal vortex prevention plate located above the vent port with a predetermined gap and covering the entire surface of the filter.   The predetermined height of the vent port is set so that the static pressure of the propellant from the upper surface of the filter to the horizontal upper end is larger than the passage resistance of the filter. Propellant tank filter device.   2. The propellant tank filter device according to claim 1, wherein an inner diameter of the vent port is set to a size such that an upward flow of the propellant is formed by bubbles rising inside the vent port. 3.   2. The propellant tank according to claim 1, wherein the predetermined gap of the vortex preventing plate is set such that a pressure loss of the propellant passing therethrough is larger than a passage resistance of the filter. Filter device.

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