JP2575361Y2 - Arc heater cooling structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc heater which is a heating device using plasma, and more particularly to a cooling structure thereof.

[0002]

2. Description of the Related Art An arc heater is a device for generating a plasma jet as a heat source for a plasma chemical reaction.

FIG. 5 shows the configuration of a conventional arc heater. A rod-shaped cathode electrode b is provided coaxially with an annular anode electrode a, and a direct current voltage is applied between these electrodes a and b to form an arc c. The working gas d is turned into a plasma state by the arc c, and is ejected from the inner surface of the anode electrode a to the outside.

On the other hand, the electrodes a and b of the arc heater are cooled with cooling water in order to prevent deterioration of characteristics due to a high arc temperature or gas temperature. Anode electrode a
The cooling water flow path f is formed within the thickness of the cooling water flow path, and cooling water is supplied to the flow path f from one side and discharged from the opposite side for cooling.

[0005]

In the cooling structure for the anode electrode a, it is necessary to mainly cool the inner surface e which is the heating surface of the electrode a. However, in the conventional cooling structure, as shown in FIG. 5B, the cooling water flows in two parts around the throat g, which is the inner side of the annular flow path f. ,
It is mainly discharged only by the cooling water flowing inside the annular flow path f, and the cooling water outside the flow path f hardly contributes to cooling. For this reason, in the conventional cooling structure, the cooling capacity is extremely low, and it has been difficult to apply it to an arc heater having a larger power.

Accordingly, an object of the present invention is to provide a cooling structure of an arc heater capable of improving a cooling capacity and maintaining high-temperature characteristics.

[0007]

According to the present invention, there is provided an arc heater in which an annular anode electrode and a rod-shaped cathode electrode are coaxially arranged. A second annular member formed with an arc passage for introducing the gas, a first annular member formed with an injection port for injecting an arc jet, and an annular partition plate formed of an insulating material interposed between the members. Forming a cooling water flow path for cooling in the first annular member;
An annular space for cooling is formed in the annular member, and a core for forming a cooling water flow path only on the inner peripheral side is provided in the annular space.

[0008]

According to the above arrangement, cooling water is separately supplied to the first annular member and the second annular member. The cooling water supplied to the annular space in the second annular member flows through a cooling water flow path formed inside the annular space and smaller than in the related art. Thereby, the flow rate of the cooling water supplied into the second annular member is increased, and the heat is uniformly transferred from the second annular member to the cooling water, so that the amount of heat transfer from the anode electrode to the cooling water can be increased. .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of an arc heater, wherein 1 is an annular SUS flange, and 2 is a flange 1.
2 which is fitted on the inner surface of
5 is a first annular member made of copper and has a pair with a second annular member 8 described later in which an arc passage 26 for introducing an arc jet is formed. A cooling water flow path 4 is formed in the block 3 including the flange 1 and the annular member 2 for flowing cooling water therein. The cooling water flow path 4 is formed in the thick wall of the annular member 2 so as to be concentric with the annular flow path 4.
a, water supply flow paths 4b, 4b for supplying cooling water to the annular flow path 4a from two locations on the outer periphery of the flange 1 in opposite directions; Roads 4c, 4c (FIG. 2). The annular flow path 4a has a sufficiently large outer circumference, and is formed by forming a groove 6 continuously in the circumferential direction on the outer circumference of the annular member 2 and fitting the annular member 2 to the flange 1. Have been. As shown in FIG. 2, the water supply flow paths 4b, 4b are linearly connected to the annular flow path 4a from outside in the radial direction, and their injection ports are connected to the throat portion 2 inside the annular flow path 4a.
They face each other with "a" in between. Drainage channel 4
c and 4c are formed so as to communicate with each other at a position orthogonal to both water supply flow paths 4b. These flow paths 4b and 4c are formed on the flange 1 so as to extend from the outer circumference to the inner circumference to form the annular flow path 4a.
Are formed by forming four communication holes 5 radially.

Reference numeral 7 denotes an FRP structure attached to one side surface of the flange 1 and has a through hole 7a at the center thereof. A plurality of steps 7 are provided on the flange 1 side of the through hole 7a.
b is formed, and the second annular member 8 made of copper is
And a cathode cover 9 made of an insulating material. The second annular member 8 holds the first annular member when the structure 7 is attached to the flange 1.
The annular member 2 is fitted into the side recess 2 b and positioned coaxially with the annular member 2. Between the first and second annular members 2 and 8, an annular partition plate 10 made of an insulating material and having a U-shaped cross section is interposed, so to speak, two annular members 2 in which a conventional anode electrode is insulated from each other. The structure is divided into eight. Thus, the reason why the split type anode electrode structure is employed in this example is that the first annular member 2 is used at the time of steady state and the second annular member 8 is used at the time of starting discharge.

The structure 7 and the second annular member 8 and the like form a block 11 which is attached to the flange 1 as an integral body, and a cooling water flow path 12 is formed in this block 11 similarly to the block 3. . The cooling water flow path 12
The flow path 12 a formed in the second annular member 8, the flow path 12
a, a water supply passage 12b for supplying cooling water from outside the structure 7, and a drainage passage 12c for discharging the cooling water in the passage 12a from the side opposite to the water supply passage 12b. That is, the communication holes 13 extend from the outer periphery of the structure 7 to the step portion 7b of the hole 7a.
Is formed, and the second annular member 8 is fitted to the stepped portion 7b so that the flow path 12a and both communication holes 13 communicate with each other.

FIG. 3 shows the shape of the flow path 12a in the second annular member 8. The second annular member 8 includes two annular pieces 14 and 15 that face each other in the axial direction. An annular groove 15a is formed concentrically in advance on the joining surface of the annular piece 15, so that the annular space 1 is formed inside the annular member 8.
6 are sectioned. The space 16 has substantially the same shape as the external appearance of the annular member 8, and the same copper core 18 as the member 8 is disposed inside the space 16. As shown in FIG. 4, the core 18 includes an annular base portion 18a having the same width W and outer diameter D as the space 16 and a partition portion 18b integrally formed on the inner surface side of the base portion 18a. The partition 18 b has the same shape as the space 16. For this reason, by providing the core 18 in the space 16 as shown in FIG. 3, a thin cooling water flow path 19 having substantially the same shape (substantially V-shaped cross section) as the inner surface of the annular member 8 is defined inside the space 16. It is formed. Holes 18c are provided at two locations on the outer periphery of the core 18 toward the center, and the holes 18c communicate with the cooling water flow path 19 through holes 18d intersecting therewith. Reference numeral 17 denotes a communication hole formed in the annular piece 15, and connects the hole 18c to the water supply channel 12b and the drain channel 12c.

In FIG. 1, a bar-shaped cathode electrode 20 is disposed at one end of the annular members 2 and 8. The cathode electrode 20 is supported by a cathode holder 21 in advance, and the holder 21 is fitted into the hole 7a of the structure 7 to be disposed inside the cathode cover 9 and coaxially with the two annular members 2, 8. Have been. In FIG. 1, 2
2 is a cooling water flow path for cooling the cathode electrode 20;
Reference numeral 3 denotes a gas flow path for injecting a working gas into the inside of the structure 7.

Next, the operation of this embodiment will be described.

Now, when a working gas is injected into the inside of the structure 7 through the gas passage 23 and a DC voltage is applied between the cathode electrode 20 and the first annular member 2, a trigger voltage is applied to the second annular member 8. After the arc generated at the tip of the cathode electrode 20 adheres to the inner surface of the second annular member 8,
The attachment point moves onto the inner surface of the first annular member 2. As a result, the injected gas is heated by the arc to be in a plasma state, passes through the inside of both annular members 2 and 8, and is injected to the outside.

At this time, cooling water is supplied to the cooling water passages 4 and 12, whereby the two annular members 2 and 8 are cooled. That is, as shown in FIG. 2, the cooling water flow path 4 is supplied with cooling water from outside the flange 1 to the water supply flow paths 4b, 4b, and the cooling water passes through the flow paths 4b, 4b to form the annular flow path 4a.
Will be introduced. At this time, since the water supply passages 4b, 4b are opposed to each other across the throat portion 2a at the center of the annular member 2, the cooling water from these passages 4b is injected into the throat portion 2a from both sides thereof. It is discharged outside the flange 1 through the discharge flow paths 4c, 4c. On the other hand, as shown in FIG. 1, cooling water is supplied to the cooling water flow path 12 from the outside of the structure 7 to the water supply flow path 12 b, and the cooling water is introduced into the annular member 8. In the annular member 8, as shown in FIG. 3, cooling water is supplied to the flow path 19 through the communication hole 17 and the holes 18 c and 18 d of the core 18. After that, it is guided to the drain passage 12c through the communication hole 17 on the opposite side. Then, the water is discharged to the outside of the structure 7 through the drain passage 12c.

As described above, in the present arc heater, the conventional anode electrode is divided into two annular members 2 and 8, and an arc is generated between the cathode electrode 20 and the annular member 2 far from the cathode electrode 20. The voltage can be made relatively larger than the current for the same input power, and the thermal efficiency can be improved. Further, since the near annular member 8 is used as a trigger at the time of arc generation, even if the discharge path is lengthened as described above, the ignitability does not deteriorate.

Since the annular flow path 4a is formed in the annular member 2 and the cooling water is injected into the throat portion 2a inside the flow path 4a from opposite sides, the cooling water in the annular flow path 4a is formed. Annular flow path 4 which does not contribute to cooling conventionally
a The cooling water on the outside can also be used for cooling, and the cooling capacity can be improved.

An annular space 16 is formed in the annular member 8 coaxially therewith, and a core 18 is provided in the space 16 so that the cooling water flow path 19 is formed only inside the space 16. The cross-section of the passage 19 can be drastically narrowed as compared with the related art, and the flow rate of the cooling water can be increased. Moreover,
Since the core 18 is provided outside the space 16 that does not contribute to cooling, the cooling performance of the annular member 8 is not hindered. Therefore, the amount of heat transferred to the cooling water can be increased to quickly suppress the heat generation of the annular member 8, and the cooling capacity can be greatly improved. Normally, in order to increase the cooling capacity, it is sufficient to increase the flow path and the amount of cooling water. According to the present cooling structure, the cooling capacity can be improved without changing the small annular member 8, which is extremely useful.

In the above-described embodiment, an example in which the cooling structure of the annular member 8 is applied to a split anode electrode structure has been described. However, it is obvious that the cooling structure may be applied to a normal integrated anode electrode. The core 1 in this cooling structure
The shape of 8 is not limited to the above.

[0022]

In summary, according to the present invention, cooling can be performed separately according to the temperatures of the first annular member and the second annular member.
In addition, the amount of heat transferred from the second annular member to the cooling water is increased, so that the cooling capacity can be improved, and the constant temperature characteristics can be favorably maintained. In addition, the present invention can be said to be an extremely useful cooling structure because the cooling capacity can be improved without forming a large cooling water passage or increasing the amount of cooling water.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an arc heater to which the cooling structure of the present invention is applied.

FIG. 2 is a cross-sectional view taken along line AA of FIG. 1;

FIG. 3 is a partially enlarged cross-sectional view of an arc heater.

FIG. 4 is a schematic configuration diagram of a core.

FIG. 5 is a sectional view showing a conventional arc heater.

[Explanation of symbols]

 Reference Signs List 1 flange 2 first annular member (anode electrode) 7 structure 8 second annular member (anode electrode) 16 annular space 18 core 19 cooling water flow path 20 cathode electrode

Continuation of front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) H05H 1/28-1/34

Claims (1)

(57) [Scope of request for utility model registration] 1. A arc heaters were provided with a cathode electrode of the anode electrode and the rod-shaped annular coaxially, the ring
An arc-shaped anode electrode introduces an arc jet
Inject arc jet with second annular member with passage formed
Between the first annular member having an injection port that forms
And an annular partition plate made of an insulating material.
Forming a cooling water flow path for cooling in the first annular member;
2 While forming an annular space for cooling in the annular member,
In the annular space, a cooling water flow path is formed only on the inner peripheral side.
An arc heater cooling structure comprising a core .