JPH116474A - Gas generator for dc arc thruster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of breakage of catalyst grains and closing of an injector. SOLUTION: A partition member 29 having a through-hole is arranged in a part situated downstream from a cylindrical type gas generator body 28, and a catalyst space 30 formed in a spot situated upper stream from the partition member 29 of the generator body 28 is filled with catalyst grains 31 to decompose a propellant 4. Further, the tip part of an injector 33 having a number of injection holes 32 formed in a part on tip side is arranged in a state to be inserted in the deep inner part of the catalyst space 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator for a DC arc thruster, and more particularly, to a gas generator for a DC arc thruster capable of preventing breakage of catalyst particles and blockage of an injector. is there.

[0002]

2. Description of the Related Art DC arc thrusters are used to control the orbit and attitude of artificial satellites and the like.

[0003] The DC arc thruster is as shown in FIG.

That is, the arc thruster main body 3 is attached to the artificial satellite main body 1 via the bracket 2, and a nozzle 5 for injecting a propellant 4 or the like is locked at one end of the arc thruster main body 3. 3 and nozzle 5
Thus, the anode 6 is constituted.

A cathode rod 8 is disposed at the inner axial position of the arc thruster main body 3 so that its tip is located in a space 7 formed in the nozzle 5. An insulating material 9 is disposed between the insulating material 9 and the insulating material 9.

The other end of the arc thruster main body 3 is connected to the anode 6 via a connector 10 and a power supply cable 11.
Discharge power supply 1 for supplying power to the cathode rod 8
2 is connected.

Further, a propellant supply passage 13 for guiding the propellant 4 and the like to the space 7 is provided inside the arc thruster main body 3.
And a propellant supply path 14, a propellant supply source 14, a fluid resistor 15 composed of multi-stage orifices and functioning as a flow rate adjusting mechanism, and a propellant valve 16 for ON-OFF provided in two stages. , 17, a thermal barrier 18, and a propellant supply channel section 20 including a gas generator 19 containing a catalyst layer for decomposing the propellant 4.

According to this configuration, the main discharge power supply device 1
By supplying power to the anode 6 and the cathode rod 8 from the power supply 2 via the power supply cable 11 and the connector 10, an arc discharge is generated between the nozzle 5 and the tip of the cathode rod 8.

In this state, the propellant 4 of the propellant supply source 14 is opened by opening the two-stage propellant valves 16 and 17 for ensuring the operation, so that the propellant supply flow path 20 and Is supplied to the space 7 via the propellant supply path 13.

At this time, the flow rate of the propellant 4 is adjusted by the fluid resistor 15 composed of multi-stage orifices, the propellant 4 is decomposed by the catalyst layer by the gas generator 19, and the propellant 4 is decomposed by the gas generator 19. The heat barrier 18 blocks the heat so that the heat generated by the heat transfer is not transmitted to the propellant valves 16 and 17 and the fluid resistor 15.

Then, the energy of the arc discharge is applied to the space 7.
The propellant 4 inside is heated, and the propellant 4 thus heated
Is sprayed from the nozzle 5 to reduce the amount of propellant 4
Thus, orbit control and attitude control of an artificial satellite or the like can be efficiently performed.

As shown in FIG. 3, the gas generator 19 has a cylindrical gas generator body 21 having two partition members 22 and 2 each having a through-hole such as a wire mesh.
3, a catalyst space is formed between the partition members 22 and 23, the catalyst space is filled with the catalyst particles 24, and the catalyst space is formed in the header space 25 formed on the upstream side of the partition member 22 inside the gas generator main body 21. , And has a structure in which a thin tubular injector 27 having an opening 26 at its tip is inserted.

In the gas generator 19, the propellant 4 that has passed through the upstream thermal barrier 18 passes through the narrow tubular injector 27, and from the opening 26 at the tip of the injector 27 to the header space 25 upstream of the gas generator main body 21. Then, the catalyst space 24 passes through the partition member 22 from the header space 25, and comes into contact with the catalyst particles 24 filled in the catalyst space. The decomposition reaction is accelerated by the catalyst particles 24, and the decomposition reaction generates heat and is vaporized. Is done.

The propellant 4, which has been vaporized and expanded in volume by the decomposition reaction, is then subjected to the pressure of expansion so that the downstream partition member 2 is expanded.
3 and is sent to the arc thruster main body 3 through the propellant supply flow path section 20.

[0015]

However, the conventional DC arc thruster gas generator has the following problems.

That is, since the DC arc thruster is operated by a small amount of the propellant 4, a small amount of the propellant 4 which has exited from the opening 26 at the tip of the injector 27 and entered the header space 25 is transferred to the header space. 25, it is difficult to distribute the propellant 4 entirely to the catalyst particles 24 filled in the catalyst space so as to cause the decomposition reaction evenly in each part of the catalyst space. In practice, a small amount of the propellant 4 entering the header space 25 is partially brought into contact with a part of the catalyst particles 24 filled in the catalyst space, and a local decomposition reaction occurs inside the catalyst space. This is the situation at present.

Then, since the decomposition reaction of the propellant 4 is a high-temperature exothermic reaction, only a part of the catalyst particles 24 contributing to the decomposition reaction of the propellant 4 are locally heated to a high temperature. There is a problem that the catalyst particles 24 are broken by thermal fatigue.

As described above, when some of the catalyst particles 24 are crushed due to thermal fatigue, fragments of the crushed catalyst particles 24 are generated by the partition member 2.
3 and the problem of going out to the arc thruster main body 3 side and the problem that the catalyst particles 24 in the catalyst space are reduced occur. In particular, in the outer space, maintenance of the DC arc thruster is required. Difficult
The above problem is serious.

Since the injector 27 has only one opening 26 at the tip, the propellant 4
Contains impurities, the impurities accumulate in the opening 26 at the tip of the injector 27 and cause blockage. Therefore, in order to prevent the blockage of the opening 26, an expensive propellant 4 of high purity is used.
I had to use

The present invention has been made in view of the above circumstances, and has as its object to provide a gas generator of a DC arc thruster capable of preventing breakage of catalyst particles and blockage of an injector.

[0021]

According to the present invention, a partition member 29 having a through hole is provided at a downstream portion of a cylindrical gas generator main body 28, and the partition member 29 of the gas generator main body 28 is provided upstream of the partition member 29. The formed catalyst space 30 is filled with catalyst particles 31 for decomposing the propellant 4, and the tip of an injector 33 having a large number of injection holes 32 on the tip side is inserted and disposed inside the catalyst space 30. The present invention relates to a DC arc thruster gas generator.

According to the above means, the following effects can be obtained.

The propellant 4 passes through the injector 33 and passes through a number of injection holes 32 formed at the tip side of the injector 33.
Directly into the catalyst space 30 of the gas generator main body 28, comes into contact with the catalyst particles 31 filled in the catalyst space 30, the decomposition reaction is promoted by the catalyst particles 31, and the decomposition reaction generates heat and is vaporized. Inflated.

The propellant 4 which has been vaporized and expanded in volume by the decomposition reaction is then sent to the arc thruster main body through the partition member 29 on the downstream side of the gas generator main body 28 at the pressure of the expansion.

The DC arc thruster is operated by a small amount of the propellant 4. However, the DC arc thruster is formed by forming a large number of injection holes 32 on the tip side of an injector 33 inserted and disposed in the inner part of the catalyst space 30. Since the propellant 4 is dispersed and injected from the large number of injection holes 32, the propellant 4 spreads over the catalyst particles 31 filled in the catalyst space 30, so that the propellant 4 is evenly distributed in each part of the catalyst space 30. Can cause a decomposition reaction to occur.

Although the decomposition reaction of the propellant 4 is a high-temperature exothermic reaction, the decomposition reaction can be caused uniformly in each part of the catalyst space 30, so that the catalyst particles 31 inside the catalyst space 30 are heated evenly, Since the particles 31 evenly cause thermal fatigue, the life of each catalyst particle 31 as a whole can be prolonged.

Therefore, some of the catalyst particles 31 are crushed by thermal fatigue, and fragments of the crushed catalyst particles 31 pass through the partition member 29 to the arc thruster main body. The problem that the catalyst particles 31 decrease can be eliminated.

Further, since a large number of injection holes 32 are formed at the tip side of the injector 33, the injection holes 32
Even if clogging occurs at several places, the propellant 4 is injected into the catalyst space 30 without any trouble, so that the inexpensive propellant 4 with low purity can be used.

As described above, according to the present invention, the catalyst particles 31
Of the injector 33 and blockage of the injector 33 can be prevented.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

Since the basic structure of the DC arc thruster is the same as that of FIG. 2, the same parts are denoted by the same reference numerals and description thereof will be omitted.

According to the present invention, a partition member 29 having a through-hole such as a wire mesh is provided at a downstream portion of the cylindrical gas generator main body 28 of the gas generator 19, and is provided upstream of the partition member 29 of the gas generator main body 28. The catalyst space 31 formed on the side is filled with catalyst particles 31.

Then, the distal end of the injector 33 having a large number of injection holes 32 on the distal end side is inserted deep into the inner part of the catalyst space 30, and the penetrating portion of the injector 33 with respect to the gas generator main body 28 is inserted into the gas generator main body 2.
Fix to 8.

Next, the operation will be described.

The basic operation of the DC arc thruster is the same as that shown in FIG.

In the gas generator 19, the propellant 4 having passed through the upstream thermal barrier 18 is supplied to the injector 33.
Through a plurality of injection holes 32 formed on the tip side of the injector 33, the catalyst space 3 of the gas generator main body 28.
When the catalyst particles 31 directly enter 0 and come into contact with the catalyst particles 31 filled in the catalyst space 30, the decomposition reaction is promoted by the catalyst particles 31, the decomposition reaction generates heat and is vaporized, and the volume is rapidly expanded.

The propellant 4, which has been vaporized and expanded in volume by the decomposition reaction, then passes through the partition member 29 on the downstream side of the gas generator main body 28 at the pressure of the expansion, passes through the propellant supply flow path section 20, and forms the arc thruster main body. Sent to 3.

The DC arc thruster is operated by a small amount of the propellant 4. However, the DC arc thruster has a large number of injection holes 32 formed at the tip side of an injector 33 which is inserted and arranged inside the catalyst space 30. Therefore, the propellant 4 is dispersed and injected from the large number of injection holes 32, so that the catalyst space 30
The propellant 4 spreads over the catalyst particles 31 filled in the catalyst space 31 so that the decomposition reaction can be caused uniformly in each part of the catalyst space 30.

Although the decomposition reaction of the propellant 4 is a high-temperature exothermic reaction, the decomposition reaction can be caused uniformly in each part of the catalyst space 30, so that the catalyst particles 31 inside the catalyst space 30 are uniformly heated and the catalyst Since the particles 31 evenly cause thermal fatigue, the life of each catalyst particle 31 as a whole can be prolonged.

Accordingly, there is a problem that some of the catalyst particles 31 are crushed due to thermal fatigue, and fragments of the crushed catalyst particles 31 pass through the partition member 29 to the arc thruster main body 3. Can be eliminated.

Also, since a large number of injection holes 32 are formed at the tip side of the injector 33, the injection holes 32
Even if clogging occurs at several places, the propellant 4 is injected into the catalyst space 30 without any trouble, so that the inexpensive propellant 4 with low purity can be used.

Thus, according to the present invention, the catalyst particles 31
And the injector 33 can be prevented from being damaged.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the spirit of the present invention.

[0045]

As described above, according to the gas generator of the DC arc thruster of the present invention, it is possible to obtain an excellent effect that damage of the catalyst particles 31 and blockage of the injector 33 can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic enlarged side sectional view of an example of an embodiment of the present invention.

FIG. 2 is an overall schematic side sectional view of a DC arc thruster.

FIG. 3 is a schematic enlarged side sectional view of a conventional example.

[Explanation of symbols]

 4 Propellant 28 Gas Generator Body 29 Partition Member 30 Catalyst Space 31 Catalyst Particle 32 Injection Hole 33 Injector

Claims (1)

[Claims] A gas generator body (2) having a cylindrical shape.
8), a partition member (29) having a through hole is provided in a downstream portion, and the partition member (2) of the gas generator body (28) is provided.
An injector having a catalyst space (30) formed upstream of 9) filled with catalyst particles (31) for decomposing the propellant (4) and having a large number of injection holes (32) at the tip side. A gas generator for a DC arc thruster, characterized in that the tip of (33) is inserted and arranged in the inner part of the catalyst space (30).