JPH05109496A - Dc plasma generating torch - Google Patents

Abstract

PURPOSE:To efficiently control the gas flow distribution by providing multiple gas injection ports made of a slit and the like. CONSTITUTION:The gas from gas guide ports 4, 5 is injected into a torch 11 from two gas injection ports 8, 9 made of a slit or a fine pipe via gas guide pipes 6, 7, and it is injected in two directions: the peripheral direction of the torch 11 and the radial direction of the torch 11. The gas flow distribution can be efficiently controlled, and a plasma flame 10 can be stably generated, with its length made variable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to applications such as injection, compound synthesis, and CVD using a direct current plasma torch.
A general-purpose torch for generating a plasma jet most suitable for each application.

[0002]

2. Description of the Related Art In a conventional torch for generating a direct-current plasma jet, there is only one gas inlet for generating plasma and there is only one direction of gas injection, and mainly a rotating flow is generated between the cathode and the anode. The plasma flame was generated while also performing the cooling effect of the electrodes.

[0003]

In the above-mentioned conventional DC plasma generating torch, gas injection is only in one direction, and the gas flow velocity distribution cannot be arbitrarily controlled. Therefore, the input of the generated plasma jet, gas type, pressure,
The optimum condition range for gas flow rate is not so wide,
It lacked versatility. Therefore, the flow distribution of the gas flow cannot be controlled arbitrarily, the stability of the plasma flame,
There was a problem in adjusting the length of the plasma flame.
The present invention has been conceived in view of the above-mentioned prior art, and an object thereof is to provide a direct current plasma generation torch capable of arbitrarily controlling the gas flow distribution.

[0004]

According to the present invention, in a direct current plasma generation torch for generating a plasma jet by discharging a direct current voltage between electrodes, a plurality of gas injection holes for generating plasma, which are slits or fine holes, are provided. The gas injection port is a direct-current plasma generation torch characterized in that the gas injected from them into the torch has at least two types of directions. The gas injection port is an inlet for injecting a gas for generating plasma into the torch. The structure of the gas injection port is, in a cylindrical torch, two directions, for example, a radial direction and a circumferential direction of the torch. Are formed so that the gas is ejected.
The ejection direction is not limited to two types, but the gas is ejected from a plurality of ejection ports in a plurality of different directions so that the flow distribution of the gas flow can be arbitrarily controlled.

[0005]

It is difficult to change the length of the plasma flame even if the gas flow rate is changed when the gas injection port for plasma generation is only for the conventional rotary laminar flow. By adding a directional gas flow, a stable gas flame can be generated by independent control of those gas flow rates, and the plasma form can be adjusted arbitrarily while setting the input, gas type, pressure, and total gas flow rate arbitrarily. become able to.

[0006]

1 is a schematic vertical sectional view of an embodiment of the present invention, FIG.
Is a cross-sectional plan view of the line AA, and FIG. 3 is a cross-sectional plan view of the line BB. In the figure, a cooling system such as an electrode and an inlet for the powdered reactant are omitted. In the figure, the cathode electrode 1 is fixed to the center of the anode electrode 2 via an insulator 3.
Reference numerals 4 and 5 are gas inlets, 6 and 7 are gas inlet pipes, 8 is a gas outlet for injecting gas into the torch 11 in the circumferential direction, and 9 is a direction (radius) toward the center of the torch 11. Direction) is a gas injection port for injecting gas. In order to inject the gas in the radial direction, the gas is supplied from the introduction port 5 and passes through the gas introduction pipe 7 annularly provided on the outer periphery of the torch 11, and the It is injected into the torch 11 in the radial direction as indicated by the arrow 2.

In order to inject the gas in the circumferential direction, the gas is supplied from the introduction port 4 and passes through the gas introduction pipe 6 annularly provided on the outer periphery of the torch, and the gas injection port 8 having a slit or a pore shape. Is injected into the torch 11 in the circumferential direction as indicated by the arrow in FIG. The shape of the gas injection ports 8 and 9 is a slit or a pore shape, but any suitable design may be performed as long as the directionality of the gas can be controlled. Also, the number of gas injection ports 8 and 9 can be appropriately selected. 2 is a cross-sectional view of the injection port 9 that injects gas in the radial direction, and FIG. 3 shows a cross section of the gas injection port 8 in the circumferential direction. In the latter, gas is uniformly ejected in the circumferential direction and flows while rotating around the cathode, while in the former, it is ejected uniformly at right angles to the cathode.
In this case, two kinds of gas are jetted, and by applying DC power between the cathode and the anode, discharge is generated at the tips of both electrodes, and the plasma flame 10 is generated. At this time, by controlling the gas flow rates of both gas injection ports 8 and 9, the plasma flame 10 can be stably generated, and the flow velocity and the length of the plasma flame can be easily adjusted arbitrarily. , Good results were obtained.

The gas introduced into the gas inlet may be the same kind of gas or different kinds of gas, and in addition to the gas injection holes 8 and 9, a gas injection port for injecting in the axial direction of the torch may be provided. Good.

[0009]

As described above, the present invention provides two or more kinds of gas injection ports for plasma generation and arbitrarily controls the gas flow rates thereof to stably generate a plasma flame, the gas flow velocity and the flame. By appropriately changing the length of the, it becomes an effective means for the purpose of plasma spraying. Also, by using a long plasma flame, the high temperature portion of the flame becomes longer and the reaction region becomes longer, so that very efficient reaction production can be achieved for the purpose of plasma CVD.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a direct current plasma generating torch according to an embodiment of the present invention.

FIG. 2 shows a cross-sectional plan view of the line AA of FIG.

3 shows a cross-sectional plan view of the line BB in FIG.

[Explanation of symbols]

 1 Cathode Electrode 2 Anode Electrode 3 Insulator 4,5 Gas Inlet 6,7 Gas Inlet 8,9 Gas Injector 10 Plasma Flame 11 Torch 41 Gas Supply Pipe

Claims (2)

[Claims] 1. A direct current plasma generation torch for generating a plasma jet by discharging a direct current voltage between electrodes is provided with a plurality of gas injection holes for plasma generation, each of which has slits or pores, and the gas injection ports are A direct-current plasma generation torch, wherein the gas injected from the torch into the torch has at least two directions. 2. The direct current plasma generation torch according to claim 1, wherein the direction of the injected gas includes a direction toward the center of the torch and a direction toward the inner circumference of the torch.