JPH06163188A - High frequency plasma generating device - Google Patents

Abstract

PURPOSE:To obtain a high frequency plasm generating device capable of easily introducing a processing substance and performing a stable substance process, by a simple constitution. CONSTITUTION:A gas flow direction control unit 5 by an insulator is provided in both end parts of a cylindrical discharge tube 1. Suction and exhaust ports 1a, 1b are provided between an internal wall of the discharge tube 1 and the gas flow direction control unit 5. An introducing port 7 is provided in the center of the gas flow direction control unit 5. A coupling coil 2 is provided in the periphery of the discharge tube 1. The coupling coil 2 is connected to a high frequency power supply 3. An electric discharge medium 6 is allowed to flow in the vicinity of an internal wall of the discharge tube 1 from the suction port 1a to the discharge port 1b. A current flows in the coupling coil 2 to generate electric discharge plasma 4 in the discharge tube 1. In the electric discharge plasma 4, the volume is reduced by separating from a tube wall by the electric discharge medium 6. Current density of the electric discharge plasma 4 is increased, to generate a high temperature. A processing substance 8 is introduced to the electric discharge plasma from the suction port 7, to perform a predetermined process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a high frequency plasma generator for synthesizing and decomposing substances by using heat and light of high temperature and high pressure plasma.

[0002]

2. Description of the Related Art High-temperature and high-pressure plasma has been used for arc lamps and arc welding, but in recent years, the field of synthesizing and decomposing substances such as industrial waste by the high-temperature and high-pressure plasma has been opened up. In order to synthesize and decompose substances by plasma, the temperature of plasma generated by arc discharge must be extremely high. One of such devices is a plasma jet device. In this plasma jet device, the anode of arc discharge is made into a nozzle shape to eject plasma, and the current density is increased and the plasma temperature is increased by narrowing the positive column of arc discharge.

However, in such a plasma jet apparatus, there is a problem that plasma having a high temperature comes into contact with the electrodes to melt the components of the electrodes, and impurities are mixed into the plasma. Therefore, a high-frequency plasma generator that does not use electrodes has been developed. This high-frequency plasma generator is
Since a high frequency power source is used and there is no electrode in contact with the arc discharge, there is an advantage that electrode material does not mix into plasma and clean plasma can be obtained. Further, the high-frequency plasma generator is capable of relatively freely selecting the discharge medium gas, is easy to control the plasma, is easy to introduce the fine powder as the non-treatment substance, and is long in the plasma residence time of the treatment substance. And the like.

As a conventional example of such a high-frequency plasma generator, the one described in "Plasma Current", written by Atsushi Kanzawa, Shinyamasha Cytec Co., Ltd. (1992) will be described below. That is, as shown in FIG. 6, a coupling coil 2 is formed around a cylindrical discharge tube 1, and the coupling coil 2 is connected to a high frequency power source 3. The discharge tube 1 has a structure in which a part of an insulator or a metal cylinder is replaced with an insulator. A discharge medium such as a rare gas is sealed in the discharge tube 1.

In the high frequency plasma generator configured as described above, when a current is passed through the coupling coil 2, an electric field in the azimuth direction is generated. Since the discharge tube 1 is formed of an insulator, the electric field is not short-circuited, and a columnar or torus discharge plasma 4 is generated in the discharge tube 1. Then, by applying a magnetic field to the discharge plasma 4 or by causing a swirling water flow, a swirling gas flow, etc. in the azimuth direction to flow around the discharge plasma 4,
Squeeze the positive columns to reduce the volume. Then, the current density of the discharge plasma 4 increases and the discharge plasma 4 becomes high in temperature. Therefore, by introducing a treatment substance into the discharge plasma 4, the treatment substance is synthesized and decomposed.
The discharge plasma 4 as described above can be used as a light emission source itself.

[0006]

However, the conventional example of the above high-frequency plasma generator has the following problems. That is, when the processing substance is introduced into the discharge plasma 4, the magnetic field applied to the discharge plasma 4 and the swirling gas flow flowing around the discharge plasma 4 are easily disturbed, and the shape of the discharge plasma 4 is stable. do not do. If a mechanism for applying a magnetic field and a mechanism for flowing a swirling gas flow etc. are provided, the configuration of the high frequency plasma generator becomes complicated. Further, the shape of the discharge plasma 4 is limited to a cylindrical shape or a torus shape, and it is difficult to change the shape of the discharge plasma 4 according to the substance to be treated. Therefore, it is not possible to select the processing time suitable for the shape and type of the processing substance, and the processing efficiency is not so good. Further, since the shape of the discharge plasma 4 is limited and the emission shape is limited, the application range as a light emitting light source is narrowed.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and the object thereof is to easily introduce a treatment substance with a simple structure and to perform stable substance treatment. A high frequency plasma generator is provided. Another object of the present invention is to provide a high-frequency plasma generator capable of efficiently performing substance treatment by arbitrarily controlling the shape of discharge plasma.

[0008]

In order to achieve the above object, the present invention according to claim 1 provides a discharge tube for confining high temperature and high pressure plasma, a high frequency power source for generating high temperature and high pressure plasma in the discharge tube, and In a high-frequency plasma generator provided with a coupling coil, an inlet for introducing a treatment substance is provided at an end of the discharge tube on a central axis of the discharge tube, and a discharge medium and other materials are provided at an end of the discharge tube. And a discharge port for supplying and discharging the substance, and the suction port and the discharge port are provided near the inner wall of the discharge tube so that the discharge medium flows near the inner wall of the discharge tube.

According to a second aspect of the present invention, an exhaust port for discharging a discharge medium and other substances and a treatment substance are introduced into a portion of the end portion of the discharge tube other than on the central axis of the discharge tube. And an insulating cylinder for supplying the discharge medium and other substances are provided on the central axis of the discharge tube, and a hole for ejecting the discharge medium and other substances onto the surface of the insulating cylinder. It is characterized in that a plurality of are provided.

Further, the present invention according to claim 3 is characterized in that the coupling coil is installed in a shape similar to that of the discharge tube.

[0011]

The operation of the high frequency plasma generator of the present invention having the above construction is as follows. That is, in the present invention according to claim 1, since the intake port and the exhaust port are provided in the vicinity of the inner wall of the discharge tube, when the discharge medium is introduced into the discharge tube from the intake port, the discharge medium is in the vicinity of the inner wall of the discharge tube. Through the discharge port. Next, when a current is passed through the coupling coil by the high frequency power source, an electric field is induced in the discharge tube and discharge plasma is generated. Since the discharge plasma is separated from the tube wall by the discharge medium flowing near the inner wall of the discharge tube, the volume of the discharge plasma is reduced. Then,
The current density of the discharge plasma increases and the discharge plasma becomes hot. Then, the treatment substance is introduced into the discharge plasma in the discharge tube through the introduction port to perform a predetermined treatment.

According to the present invention of claim 2,
The discharge plasma generated by the coupling coil is influenced by the shapes of the gas introduction pipe and the coupling coil and becomes a torus shape. Then, when the discharge medium is ejected from the hole of the gas introduction pipe, the large radius of the torus-shaped discharge plasma increases. Then, since the cross-sectional area of the discharge plasma is reduced, the current density is increased and the temperature becomes high. Therefore, the treatment substance is introduced from the introduction port to perform a predetermined treatment.

Further, in the present invention according to claim 3, the shape of the discharge tube is changed according to the shape and type of the treatment substance. Since the coupling coil is similar to the discharge tube, the discharge plasma generated by the coupling coil is similar to the cross section of the discharge tube. Then, the treatment substance is introduced from the introduction port to perform a predetermined treatment.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a high frequency plasma generator according to the present invention will be described below with reference to the drawings. The same members as those in the conventional example are designated by the same reference numerals.

(1) First Embodiment A first embodiment of the high frequency plasma generator according to the present invention will be described below. The first embodiment corresponds to the high frequency plasma generator according to the first aspect.

(A) Configuration of the Embodiment The configuration of the first embodiment is as follows. That is, FIG.
As shown in, the cylindrical discharge tube 1 is formed of an insulating material such as quartz or ceramics. A gas flow direction control device 5 is provided at one end of the discharge tube 1, and a discharge medium 6 such as a rare gas can pass between the wall of the discharge tube 1 and the gas flow direction control device 5. An intake port 1a is provided. The gas flow direction control device 5 is provided with an inlet 7 on the central axis of the discharge tube 1 at the center thereof.
Therefore, the treatment substance 8 can be introduced. A gas flow direction control device 5 is also provided at the opposite end of the discharge tube 1, and a discharge medium 6 can pass between the tube wall of the discharge tube 1 and the gas flow direction control device 5. An exhaust port 1b is provided.

The shape of the coupling coil 2 provided around the discharge tube 1 is similar to the outer shape of the discharge tube. The coupling coil 2 is connected to the high frequency power source 3 directly or via an appropriate impedance matching circuit (not shown).

(B) Operation of the Embodiment The operation of the first embodiment will be described below. That is, the discharge medium 6 at room temperature or lower is introduced into the discharge tube 1 through the intake port 1a. The discharge medium 6 is discharged from the discharge port 1b, but the intake port 1a and the exhaust port 1b are provided near the wall of the discharge tube 1, so that the discharge medium 6 flows near the inner wall of the discharge tube 1. Controlled. The gas flow velocity distribution of the discharge medium 6 is high on the wall of the discharge tube and low on the central axis. Next, when a current is passed through the coupling coil 2 by the high frequency power source 3, an electric field in the azimuth direction is induced in the discharge tube 1,
A cylindrical discharge plasma 4 is generated. The discharge plasma 4 is separated from the inner wall by the discharge medium 6 flowing in the vicinity of the inner wall of the discharge tube 1 and has a reduced diameter, so that the volume thereof is reduced. Then, the current density of the discharge plasma 4 increases and the discharge plasma 4 becomes high in temperature. When the high-temperature discharge plasma 4 is formed in this manner, the treatment material 8 is introduced into the discharge tube 1 through the inlet 7 by the action of the gas flow of the discharge medium 6 or an external force such as gravity. Introduce to and perform predetermined processing.

(C) Effect of Embodiment According to the first embodiment as described above, the discharge medium 6 flowing near the inner wall of the discharge tube 1 from the intake port 1a to the exhaust port 1b changes the diameter of the discharge plasma 4 to Since it is decreased, the plasma temperature can be raised by a simple mechanism to obtain high temperature and high pressure plasma. Further, since the introduction port 7 is provided on the central axis of the discharge tube 1, even if the treatment substance 8 is introduced, the discharge medium 6 flowing near the inner wall of the discharge tube 1 is not disturbed. Therefore, the plasma shape is stable, and efficient material treatment is possible.

(2) Second Embodiment A second embodiment of the high frequency plasma generator according to the present invention will be described below. This second embodiment corresponds to the high-frequency plasma generator according to claim 1, and is formed by enlarging the diameter of the discharge tube 1 of the first embodiment as shown in FIG. According to the second embodiment, the shape of the coupling coil 2 around the discharge tube 1 influences the generated discharge plasma 4 to have a torus shape which is substantially similar to that of the coupling coil 2.
Corresponding to the discharge plasma 4, the introduction ports 7 are provided not at the center of the gas flow direction control device 5 but at a plurality of locations around it. The second embodiment as described above has the same effects as the first embodiment and has the following advantages. That is, since the introduction ports 7 can be provided at a plurality of places, the treatment substance 8 can be easily introduced and the working efficiency is improved.

(3) Third Embodiment A third embodiment of the high frequency plasma generator according to the present invention will be described below. The third embodiment corresponds to the high frequency plasma generator according to the second aspect. The insulating cylinder according to claim 2 is a gas introducing pipe, and the holes are fine holes.
The same members as those in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted. That is, in the third embodiment, as shown in FIG. 3, a cylindrical gas introduction tube 9 made of an insulator is provided so as to penetrate both ends of the discharge tube 1. The gas introduction tube 9 inside the discharge tube 1 is provided with a large number of pores 9a. The inlet 7 is provided at the same position as in the second embodiment.

The operation of the third embodiment having such a structure is as follows. That is, the low temperature discharge medium 6 is introduced from the gas introduction tube 9 and ejected into the discharge tube 1 through the pores 9a. The gas pressure in the discharge tube 1 is the exhaust port 1b.
Regulated by The discharge plasma 4 has a torus shape influenced by the shape of the coupling coil 2 as in the second embodiment, but the discharge plasma 4 has a torus shape due to the action of the low-temperature discharge medium 6 ejected from the pores 9 a of the gas introduction tube 9. The large radius of the discharge plasma 4 becomes large. Then, the cross-sectional area of the discharge plasma 4 is reduced, so that the current density is increased and the temperature becomes high. Therefore, the treatment substance 8 is introduced through the introduction port 7 to perform a predetermined treatment.

The effects of the third embodiment described above are as follows. That is, since the large radius of the discharge plasma can be increased by the action of the discharge medium 6 ejected from the pores 9a of the gas introduction tube 9, the temperature of the discharge plasma 4 can be raised, and therefore, the high temperature and high pressure of the discharge plasma 4 can be increased by a simple mechanism. A plasma is obtained. Further, since the introduction port 7 is provided at a position corresponding to the discharge plasma 4 as in the second embodiment, even if the treatment substance 8 is introduced, the discharge medium 6 ejected from the gas introduction pipe 9 can be disturbed. Absent. Therefore, since the plasma shape is stable,
Efficient material processing becomes possible. Furthermore, by constructing the side surface or both end surfaces of the discharge tube 1 with a material that transmits light, it can be used as a high-strength discharge light generator.

(4) Fourth Embodiment A fourth embodiment of the high-frequency plasma generator according to the present invention will be described below. The fourth embodiment corresponds to the high frequency plasma generator of the third aspect. The same members as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted. That is, in the fourth embodiment, as shown in FIG. 4, the discharge tube 1 is formed into a tubular body having an oblong cross section. The coupling coil 2 is provided in a shape similar to those of the discharge tube 1. Each coupling coil 2 is connected to the high frequency power source 3.

The operation and effect of the fourth embodiment constructed as described above are as follows. That is, the coupling coil 2
Is similar to the discharge tube 1, the discharge plasma 4 generated by the electric field of the coupling coil 2 is similar to the cross section of the discharge tube 1. Then, the treatment substance 8 is introduced in the same manner as in the above-mentioned embodiment.

According to such a fourth embodiment, the discharge tube 1
And the shape of the discharge plasma 4 can be arbitrarily selected by changing the shape of the coupling coil 2. Therefore, even if the shape of the treatment substance 8 is rod-shaped, ring-shaped, powder-like, or the like, the shape of the discharge plasma 4 can be selected in accordance with the shape, and the treatment can be performed with the reaction time most suitable for each treatment substance 8. Efficient substance processing becomes possible. Further, since the shape of the discharge plasma 4 can be arbitrarily selected as described above, the emission shape of the discharge plasma 4 is not limited to the columnar shape or the torus shape. Therefore, when the discharge tube 1 is made of a light-transmitting material, it can be used in a wide range when used as a high-strength discharge light generator. Further, when the installation angle of the discharge tube 1 is changed, the position where gravity acts in the plasma 4 also changes, so that it is possible to increase the processing efficiency by changing the angle of the discharge tube 1 corresponding to the processing substance 8.

The coupling coil 2 may have a shape similar to that of the discharge tube 1. For example, as shown in FIG.
By forming the discharge tube 1 into a tubular body having a triangular cross section and forming the coupling coil 2 into a similar shape to the discharge tube 1, it is possible to adapt to the type and shape of the treatment substance 8. Furthermore, the coupling coil 2 may be arranged on the discharge tube 1 or inside the discharge tube 1.

(5) Other Examples The present invention is not limited to the above examples, but the shape, size, material, etc. of each member can be changed as appropriate. For example, the discharge tube 1 may have a structure in which a part of the metal cylinder is replaced with an insulator. Then, not only the discharge medium 6 but also the fine powder non-treated substance is caused to flow into the discharge tube, so that the clean and stable discharge plasma 4 can be obtained. In addition, the processing efficiency can be further improved by combining the fourth embodiment with other embodiments.

[0029]

As described above, according to the present invention, a simple structure is provided in the vicinity of the inner wall of the end portion of the discharge tube, or a simple structure is provided in which an insulating cylinder having a hole is provided on the central axis of the discharge tube. According to the configuration, it is possible to provide a high-frequency plasma generator capable of easily introducing a treatment substance and performing stable substance treatment. Further, according to the present invention, it is possible to provide a high-frequency plasma generator capable of controlling the shape of discharge plasma arbitrarily and efficiently performing material treatment by forming the coupling coil into a shape similar to that of the discharge tube.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of a high-frequency plasma generator according to the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the high-frequency plasma generator according to the present invention.

FIG. 3 is a longitudinal sectional view showing a third embodiment of the high-frequency plasma generator according to the present invention.

FIG. 4 is a transverse sectional view showing a fourth embodiment of the high-frequency plasma generator according to the present invention.

FIG. 5 is a transverse sectional view showing a fourth embodiment of the high-frequency plasma generator according to the present invention.

FIG. 6 is a vertical sectional view showing an example of a conventional high-frequency plasma generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Discharge tube 1a ... Intake port 1b ... Exhaust port 2 ... Coupling coil 3 ... High frequency power source 4 ... Discharge plasma 5 ... Gas flow direction control device 6 ... Discharge medium 7 ... Inlet port 8 ... Treatment substance 9 ... Gas inlet pipe 9a ... pore

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Sato 2-1, Ukishimacho, Kawasaki-ku, Kawasaki-shi, Kanagawa Stock Company, Toshiba Hamakawasaki Plant (72) Akira Ishii 2-1-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. Shares in Toshiba Hamakawasaki Plant (72) Inventor Toru Tamagawa No. 2 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Shares in Toshiba Hamakawasaki Plant (72) Inventor Yuji Okita 2-24 Harumi-cho, Fuchu-shi, Tokyo 1 Toshiba FA System Engineering Co., Ltd. In-house

Claims (3)

[Claims] 1. A high-frequency plasma generator comprising a discharge tube for confining high-temperature and high-pressure plasma, a high-frequency power source for generating high-temperature and high-pressure plasma in the discharge tube, and a coupling coil, wherein: An inlet for introducing a treatment substance is provided on the central axis of the discharge tube, and an inlet and an outlet for supplying and discharging a discharge medium and another substance are provided at an end portion of the discharge tube, and the discharge medium is the discharge. A high-frequency plasma generator characterized in that the intake port and the exhaust port are provided near the inner wall of the discharge tube so as to flow near the inner wall of the tube. 2. A high-frequency plasma generator comprising a discharge tube for confining high-temperature and high-pressure plasma, a high-frequency power source for generating high-temperature and high-pressure plasma in the discharge tube, and a coupling coil, wherein: The portion other than the central axis of the discharge tube is provided with an exhaust port for discharging the discharge medium and other substances and an inlet for introducing the treatment substance, and the discharge medium and other substances are provided on the central axis of the discharge tube. A high-frequency plasma generator characterized in that an insulating cylinder to be supplied is provided, and a plurality of holes for ejecting the discharge medium and other substances are provided on the surface of the insulating cylinder. 3. A high frequency plasma generator comprising a discharge tube for confining high temperature and high pressure plasma, a high frequency power source for generating high temperature and high pressure plasma and a coupling coil, wherein the coupling coil is similar to the discharge tube. A high-frequency plasma generator characterized by being installed in a shape.