KR101715340B1

KR101715340B1 - Inductively Coupled Plasma Apparatus

Info

Publication number: KR101715340B1
Application number: KR1020150124903A
Authority: KR
Inventors: 엄세훈; 이윤성
Original assignee: 인투코어테크놀로지 주식회사
Priority date: 2015-09-03
Filing date: 2015-09-03
Publication date: 2017-03-13

Abstract

A plasma generating apparatus according to an embodiment of the present invention includes a dielectric discharge tube; An induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; And an AC power supply unit for supplying power to the induction coil. An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

Description

[0001] Inductively Coupled Plasma Apparatus [0002]

The present invention relates to a plasma apparatus, and more particularly, to an inductively coupled plasma apparatus having an inductive coil of a multi-layer structure.

Among the various gases that make up the atmosphere, greenhouse gases are called greenhouse gases. Methane (CH4) and carbon dioxide (CO2) are the major global warming gases and are an important agenda for global warming. The synthesis of syngas (synthesis gas) according to the conversion reaction of CH4 and CO2 (CH4 + CO2 -> 2 H2 + 2 CO) is attracting attention as a major concern. The conversion of methane and carbon dioxide using atmospheric plasma is a very effective method. The atmospheric pressure plasma system has the advantage that it does not require a separate vacuum equipment required in a vacuum plasma with a quick conversion reaction and is easy to implement.

CH4-CO2 reforming has been focused on the regulatory environment for the continuous reduction of petroleum resources and the reduction of greenhouse gas emissions. Plasma technology is considered as one of the most promising ways of CH4-CO2 reforming. Plasma reforming core technologies require high conversion efficiencies and high feed-gas flow rates. To achieve this goal, the main elements of electron density, plasma temperature, and reactor structure are highlighted. Taking into account the current state of plasma CH4-CO2 reforming, it is possible to optimize the energy conversion efficiency and treatment capacity of the reactor structure and the plasma form.

Due to the continuous reduction of petroleum resources, emphasis on environmental conditions, and chemical energy transmission, synthesis gas production is concentrated on CH4-CO2 reforming (called dry reforming).

CH4 + CO2 - > 2CO + 2H2; DELTA H = 247 kJ / mol

CH4-CO2 reforming reduces methane consumption and makes carbon dioxide more attractive. To produce the same CO, methane is used less than steam reforming and partial oxidation, and CO2 is used as a carbon source in the reforming process. Although the CH4-CO reforming maintains the H2 / CO ratio at 1/1, the H2 / CO ratio can be controlled by adjusting the CH4 / CO2 ratio of the supplied gas.

In Korean integrated patents KR 1255152 and KR 1166444, coal is converted into syngas mainly composed of hydrogen (H2) and carbon monoxide (CO) in an integrated gasification combined cycle (IGCC) Thereby producing electricity. Specifically, in order to produce a syngas, a plasma gasifier using a very high frequency has been introduced. However, the ultra-high frequency gasifier has a limitation of a very high frequency electric power to be used, so that it is difficult to increase in size.

Reference is made to U. S. Patent No. 7622693 to produce syngas using inductively coupled plasma. However, an inductively coupled plasma apparatus using a single-layer induction coil is disclosed, but an induction coil having a single-layer structure is difficult to perform plasma discharge at atmospheric pressure.

SUMMARY OF THE INVENTION The present invention provides an inductively coupled plasma apparatus capable of stable discharge.

Disclosure of Invention Technical Problem [8] The present invention provides an inductively coupled plasma apparatus capable of stably discharging carbon dioxide-methane to produce syngas.

According to an embodiment of the present invention, the transformer may further include a transformer including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil.

In one embodiment of the present invention, one end of the secondary transforming coil is connected to one end of the inner induction coil, the other end of the secondary transforming coil is connected to one end of the outer induction coil, One end and one end of the outer induction coil may be disposed adjacent to each other.

In one embodiment of the present invention, the AC power supply unit includes a first output terminal and a second output terminal, the potential of the first output terminal is opposite to the potential of the second output terminal, And the outer induction coil may exhibit a potential that is opposite to the ground and has the same magnitude as the ground.

In one embodiment of the present invention, the transformer further comprises a reactance compensating capacitor connected in series to the secondary transformer coil of the transformer, and the reactance compensating capacitor may be set to cancel the reactance component of the induction coil.

In one embodiment of the present invention, a first voltage distribution capacitor connected in series to one end of a secondary transformer coil of the transformer; And a second voltage distribution capacitor connected in series to the other end of the secondary transformer coil of the transformer, wherein the first voltage distribution capacitor is connected to one end of a secondary transformer coil of the transformer and one end of the inner inductor coil, The second voltage distribution capacitor may be connected to the other end of the secondary transformer coil of the transformer and to one end of the outer induction coil.

According to an embodiment of the present invention, an auxiliary voltage distribution capacitor may be further provided for connecting the other end of the inner induction coil and the other end of the outer induction coil.

In one embodiment of the present invention, one end of the inner induction coil is connected to one end of the AC power source, one end of the outer induction coil is connected to the other end of the AC power source, And an auxiliary voltage distribution capacitor connecting the other end of the induction coil.

In one embodiment of the present invention, one end of the inner induction coil is connected to one end of the AC power source, one end of the outer induction coil is connected to the other end of the AC power source, A first auxiliary voltage distribution capacitor disposed in the first auxiliary voltage distribution capacitor; And a second auxiliary voltage distribution capacitor disposed between the other end of the outer induction coil and the ground. Wherein the first auxiliary voltage-dividing capacitor is directly connected between the inner induction coil and the ground, the second auxiliary voltage-dividing capacitor is directly connected between the outer induction coil and the ground, and one end of the first auxiliary voltage- And may be commonly connected between one end of the second auxiliary voltage capacitor and the ground.

In one embodiment of the present invention, at least one auxiliary induction coil is arranged to be spaced apart from the induction coil and the dielectric discharge tube in the direction of the central axis thereof and arranged to surround the dielectric discharge tube to generate an induction field for generating plasma Or more. An inner auxiliary induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer auxiliary induction coil in the form of a solenoid which is electrically connected in series with the inner auxiliary induction coil and overlaps and surrounds the inner auxiliary induction coil, and the induction coil and the auxiliary induction coil can be electrically connected in series .

In one embodiment of the present invention, a first impedance canceling capacitor disposed between the induction coil and the auxiliary induction coil; And a second impedance canceling capacitor disposed between the auxiliary coils. The first impedance canceling capacitor cancels the imaginary part of the impedance of the induction coil and the auxiliary induction coil, and the second impedance canceling capacitor can cancel the imaginary part of the impedance of the auxiliary coils.

In one embodiment of the present invention, an auxiliary inductor connected in series to the primary transformer coil of the transformer; And a variable capacitor connected in series to the primary transformer coil of the transforming unit.

In one embodiment of the present invention, the dielectric discharge tube may further include a swirl generator for providing a swirl flow to the dielectric discharge tube. Wherein the swirl generator is disposed at one end of the dielectric discharge tube to seal the dielectric discharge tube and provide a fluid velocity component in an azimuthal direction in a cylindrical coordinate system to provide a pressure difference in the radial direction of the dielectric discharge tube, The generated plasma can be prevented from contacting the side wall of the dielectric discharge tube.

In one embodiment of the present invention, the swirl generating portion is formed to have a tangential component periodically on a circumference of a predetermined radius along an inner wall of the dielectric discharge tube to provide a swirl flow. And an inner nozzle which is formed to have a tangential component periodically on the circumference of a constant radius inside the outer nozzle to provide a swirl flow.

In one embodiment of the present invention, it may further comprise a swirling guide disposed between the inner nozzle and the outer nozzle and extending in the longitudinal direction of the dielectric discharge tube, the dielectric material being a cylindrical shape.

In one embodiment of the present invention, the swirl generator comprises: an outer injector which provides a flow velocity in azimuthal direction components in a cylindrical coordinate system, one end of the dielectric discharge tube is coupled and includes a plurality of outer nozzles; An outer supporter coupled with the outer injector to provide an outer buffer space; An outer enclosure for sealing the outer buffer space by engaging with the outer support; An inner support inserted into the outer enclosure and providing an inner buffer space; And an inner injector portion which provides a flow rate of azimuthal direction components and is inserted into the inner support portion to seal the inner buffer space and includes a plurality of inner nozzles. The outer nozzle may be connected to the outer buffer space, and the inner nozzle may be connected to the inner buffer space.

According to an embodiment of the present invention, the swirl generator may further include a central injector part injected into the inner injector part and discharging the gas through the through hole formed at the center without swirl flow.

In one embodiment of the present invention, the outer nozzle may be formed in a helical shape while rotating in a direction of an azimuth angle on a circumference having a predetermined radius, in the longitudinal direction of the dielectric discharge tube.

In one embodiment of the present invention, the inner nozzle may be formed in a helical shape while rotating in the azimuth direction on a circumference having a predetermined radius, in the longitudinal direction of the dielectric discharge tube.

In one embodiment of the present invention, the apparatus may further include a swirling guide disposed between the inner nozzle and the outer nozzle and having a dielectric cylindrical shape extending in the longitudinal direction of the dielectric discharge tube. The swirl guide may be inserted between the inner support portion and the outer support portion.

In one embodiment of the present invention, the plasma display apparatus may further include an initial discharge generating unit disposed around the dielectric discharge tube to provide an initial discharge.

In one embodiment of the present invention, the initial discharge generating unit includes a plurality of initial discharge electrodes arranged along an outer surface of the dielectric discharge tube; And a high voltage power source for applying a high voltage to the initial discharge electrode.

The magnetic induction coil may further include a magnetic flux confinement portion formed around the induction coil and formed of a magnetic material to confine the magnetic flux generated by the induction coil.

In one embodiment of the present invention, the magnetic flux confinement portion includes a plurality of magnetic block blocks symmetrically arranged in a plane perpendicular to the center axis of the dielectric discharge tube, and the magnetic block blocks the outer surface of the induction coil, An upper surface, and a lower surface.

In one embodiment of the present invention, the flux confinement unit includes a magnetic block disposed to surround the induction coil; A thermally conductive plate formed of a nonmagnetic material arranged to surround the magnetic block so as to transmit heat of the magnetic block in contact with the magnetic block; And a cooling pipe fixed to the thermally conductive plate to cool the thermally conductive plate. The thermally conductive plate may include a slit for blocking a flow of an induction current generated by the induction coil.

In one embodiment of the present invention, the apparatus further comprises a supplementary dielectric tube disposed at the center of the dielectric discharge tube, the supplementary dielectric tube having a cylindrical structure, inserted and disposed on a concentric axis of the dielectric discharge tube, One end of the auxiliary dielectric tube is aligned with one end of the dielectric discharge tube and the auxiliary dielectric tube can guide the flow of gas in the azimuthal direction to the region where the induction coil is disposed.

In one embodiment of the present invention, a first auxiliary outer induction coil disposed to surround the outer induction coil; And a second auxiliary outer induction coil disposed to surround the first auxiliary outer induction coil.

In one embodiment of the present invention, one end of the inner induction coil is connected to one end of the AC power source, one end of the second auxiliary outer induction coil is connected to the other end of the AC power source, The first auxiliary outer side induction coil, the second auxiliary outer side induction coil, and the second auxiliary outer side induction coil are sequentially connected in series, And first to third auxiliary voltage distribution capacitors respectively disposed between the induction coils.

In one embodiment of the present invention, the induction coil and the dielectric discharge tube may further include auxiliary induction coils spaced apart from each other in the center axis direction. Wherein the auxiliary induction coil includes an auxiliary outer induction coil arranged to surround the auxiliary inner induction coil and the auxiliary inner induction coil, wherein the inner induction coil, the auxiliary inner induction coil, the auxiliary outer induction coil, The coils may be serially connected in sequence.

In one embodiment of the present invention, a first auxiliary voltage distribution capacitor connects the other end of the inner induction coil and one end of the auxiliary inner induction coil; A second auxiliary voltage distribution capacitor connecting the other end of the auxiliary inside induction coil and one end of the auxiliary outside induction coil; And a third auxiliary voltage distribution capacitor connecting the other end of the auxiliary outer induction coil and the other end of the outer induction coil. One end of the inner induction coil may be connected to one end of the AC power source, and one end of the outer induction coil may be connected to the other end of the AC power source.

A plasma processing apparatus according to an embodiment of the present invention includes a dielectric discharge tube for providing a flow of a process gas; And an induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating an inductively coupled plasma. An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil in the form of a solenoid which is serially connected while being continuously wound around the inner induction coil and overlapped to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

In one embodiment of the present invention, the potentials at the closest positions of the inner induction coil and the outer induction coil may exhibit potentials opposite in magnitude and opposite in magnitude to ground.

An antenna structure for inductively coupled plasma generation according to an embodiment of the present invention includes an inner induction coil arranged to surround a cylindrical dielectric discharge tube and wound in a solenoid shape; And an outer induction coil superimposed on the inner induction coil so as to be wound into a solonoid shape. Wherein the inner induction coil and the outer induction coil are in the form of a double cylinder having a concentric shaft structure, the inner induction coil and the outer induction coil are electrically connected in series, and the magnetic field generated by the inner induction coil and the outer induction coil is reinforced Interference.

The plasma generating apparatus according to an embodiment of the present invention can generate an inductively coupled plasma that suppresses streamer generation due to capacitive coupling discharge at atmospheric pressure or low pressure using a coaxial double induction coil.

In addition, the plasma generator according to an embodiment of the present invention can arrange voltage distribution capacitors at both ends of the induction coil to reduce the voltage applied to the induction coil, thereby suppressing the parasitic discharge between the induction coils.

1 is a conceptual diagram for hydrogen production according to an embodiment of the present invention.
2 is a schematic diagram of a gas decomposition system according to an embodiment of the present invention.
3 is a schematic diagram illustrating a plasma apparatus according to an embodiment of the present invention.
4A is a cutaway perspective view illustrating an induction coil having a laminated structure according to an embodiment of the present invention.
4B is a cross-sectional view of the induction coil of FIG. 4A.
4C is a circuit diagram illustrating the induction coil of the laminated structure of FIG. 4A.
5A is a cutaway perspective view illustrating an induction coil of a parallel structure according to an embodiment of the present invention.
5B is a cross-sectional view of the induction coil of FIG. 5A.
Fig. 5C is a circuit diagram illustrating the induction coil of the laminated structure of Fig. 5A. Fig.
6 is a cutaway perspective view illustrating a swirl providing portion of a plasma apparatus according to an embodiment of the present invention.
7 is a cross-sectional view illustrating a magnetic flux confinement portion of a plasma apparatus according to an embodiment of the present invention.
8 is a perspective view for explaining the flux confinement portion of Fig.
9 is a view for explaining a plasma apparatus according to another embodiment of the present invention.
10 is a graph showing experimental results of a plasma generating apparatus according to an embodiment of the present invention.
11 is a graph showing experimental results of a plasma generating apparatus according to an embodiment of the present invention.
12 is a view for explaining a plasma apparatus according to an embodiment of the present invention.
13 is a conceptual diagram illustrating a plasma system according to another embodiment of the present invention.
14 is a conceptual diagram of a scrubber system according to another embodiment of the present invention.
15A and 15B are conceptual diagrams illustrating a plasma generator according to another embodiment of the present invention.
16A and 16B are conceptual diagrams illustrating a plasma generating apparatus according to another embodiment of the present invention.
17 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.
18A and 18B are conceptual diagrams illustrating a plasma generating apparatus according to another embodiment of the present invention.
19A and 19B are conceptual diagrams illustrating a plasma generating apparatus according to another embodiment of the present invention.
20 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.
21 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.
22 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.
23 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.
24 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.
25 is an experimental result showing plasma holding power according to a pressure according to an embodiment of the present invention.

The inductively coupled plasma can be modeled as a transformer circuit. Accordingly, the inductively coupled plasma is referred to as a transformer coupled plasma. The induction coil acts as the primary coil of the transformer circuit, and the plasma acts as the secondary coil of the transformer circuit. A flux confinement material such as a magnetic material may be used to increase the magnetic coupling between the induction coil and the plasma. However, flux confinement materials are difficult to apply to dielectric discharge vessels of a cylindrical structure. Another way to increase the magnetic coupling between the induction coil and the plasma is to increase the inductance or winding of the induction coil. However, the increase of the inductance of the induction coil increases the impedance, which makes it difficult to efficiently transmit power. In addition, the increase of the inductance of the induction coil may increase the voltage applied to the induction coil, which may cause parasitic arc discharge. In addition, the high voltage applied to the induction coil causes capacitive coupling discharge and causes damage and thermal damage due to ion impact of the dielectric discharge vessel.

Particularly, in order to form a high-density plasma at atmospheric pressure, a structure of an induction coil capable of generating a high inductance and a high induction electric field is required. Further, at a driving frequency of several MHz or less, the impedance matching circuit can use a transformer. In this case, the load reactance of the secondary side output of the impedance matching transformer may be reduced using a reactance compensating capacitor. In addition, the turn ratio of the primary transformer coil and the secondary transformer coil of the transformer can control the magnitude of the load impedance.

According to an embodiment of the present invention, the induction coil includes an inner induction coil in the form of a solenoid and an outer induction coil arranged to surround the inner induction coil. The induction coil may be a superposed structure or a two-layer structure. Further, in order to increase the inductance of the inner induction coil and the outer induction coil, the inner induction coil and the outer induction coil are overlapped with each other such that the time-varying magnetic field interferes constructively. In this case, a high voltage due to a high inductance is applied to both ends of the induction coil. However, the outer induction coil and the inner induction coil can be extended while winding the dielectric discharge tube in a helical form while facing each other at a predetermined interval. Accordingly, the voltage of the inner induction coil and the voltage of the outer induction coil can have opposite signs at the same position. This voltage distribution can be modeled as an electric dipole. The electric dipole generates an electric field at a close position, but as the distance increases, the intensity of the electric field rapidly decreases, thereby providing a screening effect. Therefore, the structure of the induction coil can suppress the generation of the capacitive coupling plasma by the electrostatic field and increase the inductively coupled plasma efficiency. The ions generated by the capacitively coupled plasma can damage the dielectric discharge tube and damage it.

Meanwhile, the secondary side of the transformer may include an induction coil and a reactance compensating capacitor. The induction coil and the reactance compensating capacitor constitute a resonance circuit, and the resonance frequency of the resonance circuit may be the same as the drive frequency of the AC power source. Thus, stable impedance matching can be performed.

According to an embodiment of the present invention, in order to reduce the voltage applied to the induction coil, the induction coil can be voltage-divided using a capacitor. Specifically, voltage distribution capacitors may be disposed at both ends of the induction coil, respectively. Accordingly, the electrostatic field due to the screening effect is reduced, and the voltage applied to the induction coil can be reduced by the voltage distribution model. The secondary side of the transformer may also include an induction coil, a reactance compensating capacitor, and a voltage distribution capacitor. The induction coil, the reactance compensation capacitor, and the voltage distribution capacitor constitute a resonance circuit, and the resonance frequency of the resonance circuit may be the same as the drive frequency of the AC power source. Accordingly, in a state where a low voltage is applied to the induction coil, stable impedance matching can be performed.

Inductively coupled plasma is typically formed using a driving frequency of several MHz at a pressure of several hundred milliTorr (mTorr). However, such an inductively coupled plasma is difficult to perform atmospheric pressure discharge because the intensity of the induced electric field is small. Therefore, a sufficient strength of the induced electric field is required and a separate means for initial discharge is required.

When the inductively coupled plasma discharge is performed by applying RF power to the induction coil surrounding the dielectric tube, the inductively coupled plasma heats the dielectric tube, and the dielectric tube is heated and broken. Therefore, inductively coupled plasma with a high output of several tens kWatt or more has a structural limit.

A swirl may be provided to minimize the heat transfer between the inductively coupled plasma and the dielectric tube and to maintain the stability of the plasma. In a cylindrical coordinate system, the swirling flow may provide an angular momentum in the azimuthal direction to the gas or fluid to provide a density distribution along the radial direction. Thus, the inductively coupled plasma is locally limited to the central region of the dielectric tube. Thus, heat transfer between the inductively coupled plasma and the dielectric tube can be minimized.

[purpose of use]

Such an atmospheric pressure plasma apparatus can be used for various purposes. For example, the atmospheric pressure plasma apparatus can be used for synthesis of nano-powders, synthesis of single-walled carbon tubes, synthesis of fullerenes, Synthesis, synthesis of optical transparent film, cleaning, surface treatment, decomposition of gas, gasification of coal, production of syngas, treatment of harmful gas, and modification of gas.

According to one embodiment of the present invention, an inductively coupled plasma is used for plasma modification in order to generate syngas using plasma at atmospheric pressure or above atmospheric pressure. Conventional RF inductively coupled plasma is difficult to discharge at atmospheric pressure. Even when the discharge becomes a diarrheal discharge, it is difficult to maintain the discharge stability. Therefore, according to one embodiment of the present invention, an apparatus and a method capable of performing a stable large-capacity plasma discharge at a pressure of atmospheric pressure and atmospheric pressure or more are introduced.

According to an embodiment of the present invention, the plasma apparatus may be an inductively coupled plasma source which maintains a glow discharge at 0.1 atm to 5 atm. When the plasma is maintained, gases such as Ar, CO 2, CH 4, NF 3, O 2, and H 2 may be used, and several tens to several hundred liters of gas per minute are supplied and exhausted into the plasma source.

According to one embodiment of the present invention, there is provided a plasma apparatus with reduced plasma impedance and gas flow instability. Plasma devices that can handle flow rates of tens to hundreds of liters per minute have a great effect on the stability of the plasma and on the gas cracking performance of the flow dynamics and gas flow patterns. Fluid mechanics improves plasma stability and increases plasma and gas interaction.

According to one embodiment of the present invention, in order to improve the efficiency or stability of the conventional inductively coupled plasma, it is necessary to provide a plasma processing apparatus which is provided with: 1) a laminated structure antenna (coil structure) for increasing the intensity of an induced electric field; 2) Parallel structure, 3) flux confinement means for increasing the strength of the induced electric field, 4) swirl generators that can be easily mounted on a cylindrical discharge tube providing gas swirl flow, 5) swirl guide for providing a stable flow pattern, , 6) a supplemental dielectric tube structure that provides a gas at the plasma generation site to perform an endothermic reaction to efficiently utilize the heat generated in the plasma, 7) an initial discharge means for efficiently generating an initial discharge, 8) Provides a gas swirl in the same direction as the swirl generator to improve gas-plasma interaction and increase flow stability. The secondary swirl generator, 9) AC power supply for improving the plasma stability of the induction coil of the like is applied. Accordingly, the flow rate of several tens to several hundred liters per minute can be stably treated at atmospheric pressure, which can not be performed by the conventional inductively coupled plasma apparatus.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are being provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the components have been exaggerated for clarity. Like numbers refer to like elements throughout the specification.

1 is a conceptual diagram for hydrogen production according to an embodiment of the present invention.

Referring to FIG. 1, a hydrogen station 10 is an infrastructure technology for commercialization of a fuel cell vehicle and a hydrogen internal combustion engine, and is a hydrogen filling station for supplying hydrogen to fuel cells and hydrogen cars. The hydrogen station can be classified into a method of producing hydrogen from a factory, transporting it to a vehicle, supplying it to an automobile, or producing hydrogen directly from a local area and then supplying hydrogen to the vehicle. Methods for producing hydrogen by an on-site method include a water electrolysis method and a fossil fuel reforming method. The hydrogen station, which produces hydrogen on-site by reforming fossil fuels, uses a desulfurization process, reforming of the fuel by reforming the fuel, and the concentration of carbon monoxide (CO) in the generated hydrogen rich gas (WGS), high-purity hydrogen adsorption (PSA), hydrogen storage for pressurizing and storing hydrogen, and dispensing for supplying hydrogen to a fuel cell vehicle. Consists of. The fuel storage unit 11, which receives and stores the methane gas, provides methane gas to the desulfurization unit 12. [ The desulfurization reforming unit (12) removes sulfur and provides methane gas to the reforming unit (13). The reforming unit 13 receives methane and carbon dioxide as plasma modifying units and decomposes them through plasma to produce synthesis gas such as carbon monoxide and hydrogen. The reforming unit 13 cools the synthesis gas through the heat exchange unit 14 because it has high thermal energy. The cooled syngas regulates the hydrogen through the hydrogen purification unit (WGS) 15, and the hydrogen which has been regulated is supplied to the hydrogen adsorption unit 16. The hydrogen adsorbing portion 16 separates hydrogen, carbon dioxide, and methane. Separated hydrogen can be used as a fuel for fuel cells, power generation and the like.

Fuel reforming technologies are largely classified into steam reforming, partial oxidation reforming, auto-thermal reforming, carbon dioxide reforming, and plasma reforming.

The plasma reforming process has a fast starting characteristic due to the heat source generated by its own plasma, facilitates reaction control, and has a high hydrogen conversion rate compared to energy supply. It is also applicable to various fuel properties. However, the choice of product is difficult to control and the initial equipment cost is high. According to one embodiment of the present invention, a steady reforming reaction can be maintained at atmospheric or atmospheric pressure using a source of inductively coupled plasma with a plasma reforming apparatus.

2 is a schematic diagram of a gas decomposition system according to an embodiment of the present invention.

Referring to Figure 2, the gas cracking system 20 may be used for the production of syngas or for various gas cracking. The gas decomposition system may be a plasma reforming apparatus using carbon dioxide and methane as raw materials. In the case of the synthesis gas production, the raw material gas may be methane and carbon dioxide.

As an example of the gas decomposition system, a gas decomposition system using carbon dioxide and methane as a raw material is described.

The gas decomposition system 20 may include a gas supply 21, a gas cracking inductively coupled plasma device 22, and an exhaust and gas trap 23. The gas-decomposable inductively coupled plasma devices 20 may be connected in series to each other. Thus, the treatment flow rate can be increased. The gas cracked inductively coupled plasma device 20 may operate at atmospheric pressure.

The gas supply unit 21 can supply various fuels to the plasma apparatus. The fuel may be methane and carbon dioxide. The fuel may be biogas or various hydrocarbon gases. The gas supply unit 21 may provide an auxiliary gas such as argon (Ar) for plasma initial discharge or discharge stability.

The exhaust and gas collection section 23 can collect and process the generated syngas. The exhaust and gas collecting section 23 can measure the concentration of carbon monoxide and collect carbon monoxide, hydrogen, and the like. The gas-decomposable inductively coupled plasma apparatus can be combined with a heat exchanger that recovers the generated heat. Further, the exhaust and gas collecting section 23 may be configured to include a hydrogen purification section and a hydrogen adsorption section.

3 is a schematic diagram illustrating a plasma apparatus according to an embodiment of the present invention.

Referring to FIG. 3, the inductively coupled plasma apparatus 100 includes a dielectric discharge tube 110; A swirl generating unit 140 receiving the gas and providing a swirl flow in the dielectric discharge tube; An induction coil 120 disposed to surround the dielectric discharge tube 110 to generate an induction electric field to generate plasma; And an AC power supply unit (129) for supplying power to the induction coil; . The inductively coupled plasma apparatus 100 may decompose raw material gases (methane and carbon dioxide) at atmospheric pressure or higher than atmospheric pressure to produce syngas (carbon monoxide and hydrogen).

The dielectric discharge tube 110 isolates the discharge region where the discharged plasma is located from the outside. The pressure of the dielectric discharge tube 110 may be substantially atmospheric or atmospheric pressure or higher. If the decomposition gas leaks out, it may be harmful. Therefore, when a harmful gas is generated, the dielectric discharge tube can be sealed. The dielectric discharge tube may be cylindrical. The dielectric discharge tube may preferably be cylindrical. However, since the dielectric discharge tube 110 operates at atmospheric pressure, the dielectric discharge tube 110 can be variously deformed, such as a cylinder, a cylinder, or a rectangular tube. The material of the dielectric discharge tube 110 may be quartz, ceramic, alumina, or sapphire. It is preferable that the dielectric discharge tube has a quartz structure that is easy to manufacture and resistant to thermal shock. The dielectric discharge tube 110 is formed of a non-conductive material to transmit an induced electromotive force.

The atmospheric pressure inductively coupled plasma may be discharged by the induction coil 120. The pressure inside the dielectric discharge tube 110 may preferably be in the range of 300 Torr to 1000 Torr. When the pressure of the dielectric discharge tube 110 is close to the atmospheric pressure, there is a disadvantage in that inductively coupled plasma is difficult to generate, but the pressure is high and a large amount of flow rate can be processed. On the other hand, when the pressure of the dielectric discharge tube 110 is in the range of several torr to 100 torr, the inductively coupled plasma can be easily generated, but the flow rate is significantly reduced and the swirl flow is reduced. That is, by increasing the diffusion coefficient of the gas due to the pressure decrease, the dielectric discharge tube 110 to which the high power of several tens kWatt or more is applied can be damaged by heat.

The diameter of the dielectric discharge tube 110 affects the inductance of the induction coil 120 surrounding the dielectric discharge tube. When the inductance of the induction coil is increased, the AC power source or the RF power source can not efficiently supply power to the load (including the induction coil). Thus, the diameter of the dielectric discharge tube 110 may range from a few centimeters to a few tens of centimeters. Preferably, the outer diameter of the dielectric discharge tube may be on the order of 8 centimeters. The inductance of the induction coil may range from 5 uH to 20 uH.

Conventional solenoid-type induction coils are difficult to generate an induction field strong enough to sustain discharge and induce sufficient gas decomposition. The induction electric field is easily generated through the induction coil as the frequency increases, but it is difficult to produce a power source that generates more than tens of kilowatts (kWatt) of electric power as the frequency increases. Typically, in the case of a frequency range of several hundred kilohertz (kHz) or less, a power source of tens of kWatt or more can be produced. In the frequency region of several MHz or more, it is difficult to produce a power source of several tens kWatt. Therefore, in order to supply electric power of several tens kWatt or more, the AC power supply unit 129 may have a frequency of several MHz or less. And may be 100 kHz to 4 MHz, preferably 400 kHz, of the AC power supply 129. Also, the AC power supply 129 may be a variable frequency power source in order to improve impedance matching or discharge stability. That is, the frequency of the initial stage of the discharge may be different from the frequency of the state where the discharge is stably maintained.

The induction coil 120 must induce a strong electric field in order to discharge atmospheric plasma using a gas such as CO2 or CH4. In order to increase gas reaction efficiency, a high energy per unit time must be applied to the plasma . To this end, the antenna or induction coil has the following characteristics. Inside the induction coil 120, a coolant such as pressurized air or water may flow for cooling. Nevertheless, even when the refrigerant flows into the induction coil, when the induction coil is supplied with electric power of several tens kWatt or more, the induction coil can be heated and melted. Therefore, the induction coil is formed of a copper material, and can be plated with silver to reduce the surface resistance.

[Structure of multilayer induction coil]

The atmospheric pressure inductively-coupled plasma system applies very high frequency (VHF) power to induce a high electric field in the discharge space. Typically, the atmospheric pressure inductively coupled plasma apparatus uses 27.4 MHz. In the case of the frequency of 27.4 MHz, plasma discharge and maintenance are easy, but due to technical limitations of RF generator and impedance matching, it is impossible to apply high power to plasma with high efficiency. Therefore, gas decomposition and CH4-CO2 plasma reforming reaction can not be efficiently performed. In particular, the CH4-CO2 plasma reforming reaction requires a thermal plasma. Until now, no inductively coupled plasma device using electric power of several tens kWatt or more has been required at a low frequency of several MHz or less. Typically, atmospheric pressure discharges are readily discharged using a plasma torch. Therefore, there is no need for inductive coupling discharge for atmospheric pressure discharge. However, in the case of a plasma torch, the electrodes are consumable, so replacement and repair often occur. In the case of atmospheric pressure microwave discharge, although the discharge is easy, the magnetron which is mechanically complicated and outputs a power of several tens kWatt or more is practically absent or too expensive. On the other hand, inductively coupled plasma, induction electric field does not penetrate perpendicularly to the dielectric discharge tube, and damage by ion bombardment is small. The inductively coupled plasma generates an electric field in the central axis direction of the cylindrical dielectric discharge tube 110. The swirl flow can confine the plasma to the central region of the dielectric tube and maintain a stable discharge.

When a high power of several tens kWatt or more with a low frequency of several MHz or less is applied, a strong induction electric field necessary for discharging can not be formed. In order to generate a strong induction field, a new induction coil structure is proposed. The induction coil and the antenna are used interchangeably in the following description. In the case of an inductively coupled plasma (ICP) antenna, the intensity of the induced electric field delivered to the plasma is proportional to the current and frequency of the induction coil, and is proportional to the square of the number of turns (number of turns). Therefore, as the number of turns of the induction coil (or antenna) increases, a higher current can be applied to the plasma. However, as the number of windings of the solenoid coil increases, the energy is dispersed in the longitudinal direction of the dielectric discharge tube due to spatial restrictions. In addition, the high inductance (impedance) of the induction coil makes it difficult to transfer power from the RF generator to the induction coil (antenna). It is important to increase the density of the electric field formed around the plasma, so that the number of windings per unit length should be maximized with respect to the longitudinal direction of the dielectric discharge tube. According to the experimental results, induction coils of a single layer structure are difficult to generate inductively coupled plasma stably.

Therefore, we designed the induction coil in a certain number of times and then superimposed the induction coil on the outer side. That is, a multi-layered induction coil is proposed. The number of windings and the number of layers depend on the diameter of the dielectric discharge tube 110 and the inductance value suitable for impedance matching. For example, when a 4 turn antenna is used three times in an 80 mm diameter dielectric discharge tube, the antenna resistance is 180 mOhm, the antenna inductance is 8 μH, and the antenna can be supplied with 180 A current.

The AC power supply unit may supply AC power in the range of 100 kHz to 4 MHz to the induction coil. An impedance matching network 128 may be disposed between the AC power supply 129 and the induction coil 120 for impedance matching.

4A is a cutaway perspective view illustrating an induction coil having a laminated structure according to an embodiment of the present invention.

4B is a cross-sectional view of the induction coil of FIG. 4A.

4C is a circuit diagram illustrating the induction coil of the laminated structure of FIG. 4A.

4A to 4C, the induction coil 120 may be in the form of a multilayered solenoid. The number of induction coils 120 may be two or three. The number of turns of each layer may be 3 to 5.

The induction coil 120 includes a lower solenoid coil 122 arranged to surround the dielectric discharge tube 110; And an upper solenoid coil 126 arranged to surround the lower solenoid coil. The lower solenoid coil 122 and the upper solenoid coil 126 are connected in series and the direction of the magnetic field generated by the lower solenoid coil and the direction of the magnetic field generated by the upper solenoid coil may be the same.

The induction coil 120 may further include an intermediate solenoid coil 124 disposed between the lower solenoid coil 122 and the upper solenoid coil 126. The lower solenoid coil 122, the intermediate solenoid coil 124, and the upper solenoid coil 126 may be connected in series. The direction of the magnetic field generated by the lower solenoid coil 122, the intermediate solenoid coil 124, and the upper solenoid coil 126 may be the same. The frequency of the AC power source may be 100 kHz to 4 MHz.

Each of the lower solenoid coil 122, the intermediate solenoid coil 124, and the upper solenoid coil 126 may include a spacer 121 surrounding an outer periphery of the pipe. The spacer 121 may be an insulating material that does not melt at a high temperature and has a high dielectric breakdown voltage. The spacer can prevent contact of the induction coil and maintain a constant gap. If the interval of the induction coils is too narrow, atmospheric pressure discharge may occur. The induction coil is made of a pipe, and the refrigerant can flow into the induction coil.

According to a modified embodiment of the present invention, the induction coil is a solenoid coil structure having a two-layer structure, and the induction coil can have four turns in the lower layer and four turns in the upper layer.

[Reduction of the actual resistance of the induction coil by the parallel structure]

When the atmospheric pressure CO2 / CH4 plasma is discharged, the real resistance of the plasma decreases sharply from 0.6 to 0.9 Ohm compared with the argon (Ar) plasma. The magnitude of the required current increases due to the decrease in the absolute value of the impedance. At this time, a current of about several hundred amperes (A) is required. If the resistance of the structure (induction coil self-resistance or contact resistance of the connection site) is inferior to the actual resistance of the plasma, the transmission efficiency of the supplied power is reduced and energy is lost to the fixture. Therefore, the structure is damaged and the possibility of an accident occurs.

Among the instruments, the highest room resistance is the antenna's own room resistance (about 0.18 Ohm). The antenna's own field resistance can account for 80% of the total device resistance. Even if the antenna is water cooled to reduce the possibility of damage, the problem of energy loss remains. The energy loss of the antenna during CO2 discharge is more than 20%, so improvement is needed. A parallel connection structure of the antenna is proposed.

5A is a cutaway perspective view illustrating an induction coil of a parallel structure according to an embodiment of the present invention.

5B is a cross-sectional view of the induction coil of FIG. 5A.

Fig. 5C is a circuit diagram illustrating the induction coil of the laminated structure of Fig. 5A. Fig.

5A to 5C, the induction coil 430 may include a plurality of induction coil modules 430a and 320b having a plurality of layers. The induction coil modules 430a and 320b of the multi-layer structure are spaced apart from each other and electrically connected in parallel to each other, and the magnetic fields generated by the induction coil module of the multi-layer structure may interfere with each other. The first induction coil module 320a may include a lower solenoid coil 322a, an intermediate solenoid coil 324a, and the upper solenoid coil 326a. The second induction coil module 320b may include a lower solenoid coil 322b, an intermediate solenoid coil 324b, and the upper solenoid coil 326b.

Case 1 Case 2 Case 3 3-layer structure
(10 turns) 3-layer structure + reinforcement intervention parallel
(10 X 2 turns) 3-layer structure + reinforcement intervention parallel
(13 X 2 turns) L = 8.1 uH
R = 180 mOhm L = 6.8 uH
R = 91 mOhm L = 8.9 uH
R = 120 mOhm

In the case of two antenna structures (case 2 and case 3), the resistance of the antenna is reduced to about half and the inductance is about 65% of the original. Therefore, the impedance matching of the AC power source has a wider range, and the antenna resistance is reduced and the loss is also reduced. And because of the low inductance, the number of windings can be increased and the plasma energy coupling is improved.

[Gas injection and swirl structure]

6 is a cutaway perspective view illustrating a swirl providing portion of a plasma apparatus according to an embodiment of the present invention.

Referring to FIG. 6, the gas supply unit 21 can supply methane, carbon dioxide, argon, and a combination gas thereof. The gas supply unit 21 may provide different gases and flow rates depending on an initial discharge mode and a main discarkage mode. For example, in the initial discharge mode, the argon gas and carbon dioxide may be mainly supplied to the dielectric discharge tube 110. On the other hand, in the main discharge mode, carbon dioxide and methane gas may be supplied to the dielectric discharge tube 100. In addition, the initial discharge mode is mainly discharged in a charge coupled mode using a high voltage, and the main discharge mode is mainly discharged in an inductive coupling mode using a high current.

When the dielectric discharge tube 110 confines the plasma, strong heat is transmitted to the outer wall. Accordingly, since the dielectric discharge tube 110 can be damaged by heat, the dielectric discharge tube 110 provides a swirling flow or a swirling flow of strong gas to the surface of the dielectric discharge tube 110 as compared with the center of the dielectric discharge tube 110. Accordingly, the swirl flow induces the plasma to the center and isolates the plasma from the outer wall of the dielectric discharge tube. Thus, the dielectric discharge tube 110 is protected from heat. Also, the high pressure of the atmospheric pressure inhibits the transfer of the thermal energy of the plasma and the heated gas to the dielectric discharge tube. In order to enable such an effect, a swirling gas flow is required at a high speed on the surface of the dielectric discharge tube 100. Further, a pressure difference between the center and the inner surface of the dielectric discharge tube is required. Also, formation of local vortices should be suppressed.

In order to rotate the gas in a desired direction, there is a swirl generating part 140 causing swirling. The swirl generating unit 140 can induce the swirl flow stably while minimizing thermal contact with the plasma by the induction coil.

1 to 3 of the prior art US 7,622,693, a plasma vessel is a double wall structure having an outer wall and an inner wall, and a slit is formed in the inner wall to generate a swirl flow. However, such a structure can not stably generate a swirl flow. Further, the inner wall can be damaged by the heat of the plasma. Further, when the inner wall is made of a dielectric material, it is very difficult to manufacture the slit. Further, when the inner wall is a conductive one, the inner wall is directly heated by the induction electric field of the induction coil, and is damaged by heat.

Therefore, another method is required to stably provide the swirl flow in the inductively coupled plasma. According to an embodiment of the present invention, the swirl generator 140 is coupled to one end of the dielectric discharge tube 110 to provide a swirl flow through the nozzle. The swirl flow may proceed along the dielectric discharge tube 110 while forming a swirl in the dielectric discharge tube. When the swirl generator 140 and the induction coil 120 are disposed close to each other (for example, several centimeters), the strong heat energy generated by the induction coil 120 is transmitted to the swirl generator 140 ). &Lt; / RTI > Therefore, the swirl generator 140 and the induction coil 120 can be separated from the swirl generator 140 by more than a few centimeters.

The swirl generation unit 140 is designed by dividing the nozzles in order to control the position of the atmospheric plasma and optimize the reaction. As a result, the discharge stability of the plasma and the reaction efficiency of the gas were increased. The nozzle includes an outer nozzle 143a and an inner nozzle 144a. Alternatively, the nozzle may include an outer nozzle 1443a, an inner nozzle 144a, and a center nozzle 145. [ The outer nozzle 143a may be supplied with gas through the outer nozzle gas supply line 141a. The inner nozzle 144a may be supplied with gas through the inner nozzle gas supply line 141b. The center nozzle 145 can be supplied with gas through the center nozzle gas supply line 141c.

The swirl generator 140 may include an outer nozzle 143a for providing an outer swirl flow and an inner nozzle 144a for providing an inner swirl flow.

In addition, according to a modified embodiment of the present invention, the swirl generator 140 includes an outer nozzle 143a providing an outer swirl flow, an inner nozzle 144a providing an inner swirl flow, And a central nozzle 145 for injecting the water. The supply of the gas through the center nozzle 145 can suppress the contact between the dielectric discharge tube 110 and the plasma and improve the plasma stability.

When the swirl flow is provided using only the outer nozzle 143a, the plasma stability deteriorates, and the plasma can contact the inner wall of the dielectric discharge tube. Therefore, when the inner nozzle 144a is additionally disposed, the plasma stability can be improved.

The swirl generating unit 140 may divide the gas into two or three portions from the center to the edge of the concentric circle of the dielectric discharge tube. The outer nozzle 143a provides swirl flow to isolate the cooling and plasma at the inner edges of the dielectric discharge tube. An inner nozzle 144a for adjusting a pressure difference is disposed between the center nozzle 145 and the outer nozzle 143a. The inner nozzle 144a can adjust the pressure difference in the radial direction of the dielectric discharge tube.

The inner nozzle 143a and the outer nozzle 144a may discharge a gas composed mainly of carbon dioxide to provide swirl flow. The central nozzle 145 can discharge gas (for example, gas containing methane as a main component) for the reaction.

The swirl generator 140 and the induction coil 120 may be spaced apart from each other by several centimeters or more. In this case, when the distance between the swirl generating part 140 and the induction coil 120 is sufficiently spaced to suppress the heating of the swirl generating part 140, the swirl flow is not continued to the area where the plasma is generated . That is, the swirl guide 112 is disposed to continue the swirl flow to the region where the induction coil is disposed.

The swirl guide 112 is cylindrical in shape and inserted into one end of the dielectric discharge tube to form a concentric structure. Specifically, the swirl guide 112 may be mounted on the swirl generating part 140 and extend in the direction of the center axis of the dielectric discharge tube 112. Accordingly, the fluid having the azimuthal velocity component supplied between the dielectric discharge tube and the swirl guide can stably provide swirl flow. The swirl guide 112 may be short so as not to reach the discharge area where the plasma is generated by the induction coil. When the swirl guide 112 extends into the discharge region, the plasma can thermally damage the swirl guide 112. The swirl guide 112 may be a dielectric material such as quartz, ceramic, or sapphire. In addition, the swirl guide 112 and the dielectric discharge tube 110 may have a concentric structure in which their central axes coincide. The swirl guide 112 may provide a frictional force to stably form an outer swirl flow by the outer nozzle and an inner swirl flow by the inner nozzle. Further, the swirl guide 112 serves as a guide for guiding the gas flow at the edge to a desired level, and serves to reduce the exposure of the plasma to the surface of the conductor of the gas nozzle. In the absence of the swirl guide, stable plasma maintenance is difficult.

The swirl generator 140 includes an outer nozzle 143a periodically disposed on a circumference having a predetermined radius along the inner wall of the dielectric discharge tube and providing a swirl flow. And an inner nozzle 144a that is periodically disposed on the circumference of a constant radius inside the outer nozzle and provides a swirl flow. The swirl guide 112 may be disposed between the inner nozzle and the outer nozzle and may have a cylindrical shape of a dielectric material extending in the longitudinal direction of the dielectric discharge tube 110.

Specifically, the swirl generator 140 includes an outer injector portion 245 providing a flow rate of an azimuthal component in a cylindrical coordinate system, coupling the dielectric discharge tube to one end of the dielectric discharge tube and including a plurality of outer nozzles 143a; An outer support 244 coupled to the outer injector 245 to provide an outer buffer space 143b; An outer enclosure (243) coupled with the outer support to seal the outer buffer space (143b); An inner support 242 inserted inside the outer enclosure 243 and providing an inner buffer space 144b; And an inner injector portion 248 that provides a flow rate of azimuthal direction components and is inserted into the inner support portion 242 to seal the inner buffer space and includes a plurality of inner nozzles 144a. The outer nozzle 143a may be connected to the outer buffer space 143b and the inner nozzle 144a may be connected to the inner buffer space 144b.

The outer injector portion 245 includes a plurality of outer nozzles disposed on a circumference of a constant radius. The outer nozzles 143a are arranged inside the dielectric discharge tube at regular intervals. The outer injector portion 245 may have a rectangular ring shape with a polygonal surface, and may have a portion extending outside the ring shape in the direction of the central axis. The extended portion may be disposed to surround the outer surface of the dielectric discharge tube 110. The outer injector portion 245 engages the outer support portion 244.

The outer support portion 244 is disposed to surround the outer surface of the outer injector portion 245 and the outer support portion 244 is provided with a recess disposed on a circumference of a constant radius for forming the outer buffer space 143b Section. The outer buffer space 143b is connected to the outer nozzle 143a, and the outer nozzle 143a moves in the helical direction to provide swirl flow.

The outer enclosure 243 is disposed on the lower surface of the outer support 244 and hermetically seals the outer buffer space 143b. The outer enclosure 243 may include a gas passage through which gas travels through the gas line. The gas passage may be connected to the outer buffer space 143b.

The inner support 242 is disposed to be inserted inside the outer enclosure 243. In addition, the inner support 242 is disposed on the lower surface of the outer enclosure 243. Accordingly, the inner support portion 243 may include a cylindrical body portion having a large diameter and a cylindrical portion having a small diameter and extending from the center of the body portion. One end of the swirl guide 112 may be disposed between the outer surface of the extended portion and the inner surface of the outer support portion 244. One end of the inner support portion 242 includes a cylindrical depression, and the inner injector portion 248 is inserted into the depression. One end of the extension of the inner support 242 includes a recessed structure with a jaw and a constant radius on the circumference, and the recessed structure may provide the inner buffer space 144b. The inner buffer space 144b is sealed by the inner injector portion 248.

The inner injector portion 248 includes a plurality of the inner nozzles 144a disposed on a certain radius and the inner nozzle 144a is connected to the inner buffer space 144b. The inner buffer space 144b may be connected to a fluid passage through the inner support 242 through an external gas line.

The center injector portion 247 may be inserted into the central axis of the inner injector 242. The central injector portion 247 may include one central nozzle 145. The center nozzle 145 of the central injector portion 247 may be connected to the center buffer space 145b formed on the center axis between the inner support portion 242 and the inner injector portion 248. [ The lower support portion 241 may be mounted on the lower surface of the inner support portion 242. An upper support 246 may be disposed on the outer support 244 to press the O-ring disposed on the outer injector 244 to maintain the seal.

Further, in order to improve the stability of the swirl flow, the auxiliary swirl generator 170 may be disposed. The swirl generator 140 may be disposed at one end of the dielectric discharge tube 110 and the auxiliary swirl generator 170 may be disposed at the other end of the dielectric discharge tube 110. The swirl generator 140 and the auxiliary swirl generator 170 may provide swirling flow in the same direction to provide stable flow.

The auxiliary swirl generator 170 may have a toroidal shape having an inner diameter equal to the inner diameter of the dielectric discharge tube 110. Accordingly, the swirl flow can stably proceed in the direction of the central axis of the dielectric discharge tube 110 without being disturbed by the auxiliary swirl generating portion 170.

The auxiliary swirl generator 170 may additionally provide a swirl flow in the same rotational direction as that of the swirl flow provided by the swirl generator 140. Accordingly, the auxiliary swirl generator 170 can improve the stability of the swirl flow. In addition, the main component of the gas provided by the auxiliary swirl generator 170 may be a gas participating in an endothermic reaction such as methane. Specifically, the swirl generator 140 provides an exothermic reaction gas such as carbon dioxide, and the heat generated by the plasma can operate the endothermic reaction of methane provided by the sub swirl generator 170. The insertion positions of the endothermic reaction gas and the exothermic reaction gas are spaced apart from each other, and the discharge stability and the reaction efficiency can be increased.

[Gas input position]

The injection position and flow rate of CH4 during plasma decomposition are very important. CH4 can perform an endothermic reaction easily separating into carbon and hydrogen gas at a suitable temperature (930 K) or more. Methane (CH4) tends to easily absorb electrons, which, when raised, lower the resistance of the plasma and weaken the discharge. Therefore, when the CH4 gas is injected into the portion having high heat in the tail portion of the plasma after passing through the plasma generation region by the auxiliary swirl generation portion 170, the CH4 gas reuses the heat to be separated into carbon, Can combine with oxygen atoms separated from CO2 to produce carbon monoxide. At this time, the efficiency increases due to the heat recovered, and the discharge can also be improved.

The swirl generating part 140 may be mounted on one end of the dielectric discharge tube 110. The auxiliary swirl generator 170 may be disposed at the other end of the dielectric discharge tube 170. The gas can swirl from one end of the dielectric discharge tube 110 to the other end of the dielectric discharge tube 110. As the carbon dioxide progresses in the discharge region where the plasma is generated, the carbon dioxide decomposes to generate carbon monoxide and heat. The generated heat may be used in an endothermic reaction for decomposing methane provided by the auxiliary swirl generator 170. In addition, the auxiliary swirl generator 170 generates a swirl in the same direction as that of the swirl generator 140 to provide a stable flow. The nozzle direction of the auxiliary swirl generator 170 may have a tangential component and a central axis direction. Accordingly, the methane gas discharged from the auxiliary swirl generator 170 can be stably formed while forming a swirl.

The auxiliary swirl generator 170 may include an auxiliary nozzle 173 for providing swirl flow. The auxiliary swirl generator 170 may provide hydrocarbons such as methane at the rear end of the plasma generation region. The auxiliary swirl generator 170 is hollow toroidal in shape and a plurality of auxiliary nozzles 173 are connected to the auxiliary buffer space 174 and the traveling direction of the auxiliary nozzle 173 is a radial direction component in the cylindrical coordinate system. And an azimuthal direction component. Accordingly, the gas that has advanced through the auxiliary nozzle 173 can provide the swirl flow.

[Cooling method]

Atmospheric pressure thermal plasma releases strong heat and radiant heat to the outside during discharge. The outer wall and surrounding structures may be damaged by heat. Therefore, in order to solve this problem, the plasma apparatus has a new structure and functions.

A silicone O-ring may be used to seal between the outer wall of the dielectric discharge tube 110 and the structure (or swirl generating portion, auxiliary swirl generating portion). However, since the O-ring is broken at a high temperature of 300 degrees Celsius or more, cooling of the peripheral portion is required. The cooling ring 142 may be arranged to surround one end of the dielectric discharge tube 110 while contacting the lower surface of the swirl generating part. The cooling ring 142 may be a water cooling jacket. The cooling ring 142 may be cooled by the refrigerant. The auxiliary cooling ring 171 may be arranged to cover the other end of the dielectric discharge tube 110 while being in contact with the upper surface of the auxiliary swirl generating part 170. The auxiliary cooling ring 171 can be cooled by the refrigerant.

According to a modified embodiment of the present invention, as a method for cooling the dielectric discharge tube 110, a ceramic material with good thermal conductivity can mold the induction coil 120. The induction coil 120 is buried in a ceramic paste, and the ceramic paste is hardened to form a ceramic block. The ceramic block may be separately cooled by a cooling pipe spaced from the induction coil 120 and buried in the ceramic block. The ceramic block may be molded integrally with the dielectric discharge tube 110 to conduct conduction to the dielectric discharge tube 110.

The outside of the dielectric discharge tube 110 and the induction coil are subject to ozone and heat generation due to high temperature and high current. Therefore, the safety case 190 is disposed so as to surround the induction coil 120. The safety case 190 may be in the form of a sealed cylinder. The safety case 190 includes an air inlet and an air outlet. The pressurized air injected through the air inlet cools the dielectric discharge tube and induction coil. The exhaust system isolates the ozone from the air exiting the air outlet.

The temperature measuring unit 196 may be disposed at the other end of the dielectric discharge tube 110 (the point where it is exhausted through the induction coil). The temperature measuring unit 196 measures the temperature of the dielectric discharge tube 110. The temperature of the dielectric discharge tube may depend on the internal gas temperature. The measured temperature can be used for process control. In the case of plasma, when the temperature is 350 to 600 degrees centigrade based on the measurement position, the atmospheric pressure discharge is stably maintained. If the temperature is lower than this range, the plasma becomes unstable and discharge is stopped. Also, if the temperature is too high, the dielectric discharge tube 110 and peripheral equipment may be damaged. Therefore, when the temperature is too high, the AC power supplied to the induction coil or the gas supply flow rate can be controlled to maintain the temperature.

The auxiliary swirl generator 170 may be connected to the auxiliary chamber 182 at a lower portion thereof. The auxiliary chamber may be a dielectric material or a metal material. The auxiliary chamber 182 may provide a space for reaction in the case of a synthesis gas production process using methane-carbon dioxide. The length of the auxiliary chamber 182 may be several centimeters to several meters.

The auxiliary chamber 182 may be mounted to the processing vessel 180. The process vessel 180 may be subjected to a post-process to use the decomposed gas or to collect the required gas in the decomposed gas.

[Magnetic body structure for improving discharge efficiency]

7 is a cross-sectional view illustrating a magnetic flux confinement portion of a plasma apparatus according to an embodiment of the present invention.

8 is a perspective view for explaining the flux confinement portion of Fig.

Referring to FIGS. 7 and 8, the magnetic structure disposed around the induction coil 120 may confine the magnetic field, thereby increasing the actual resistance of the plasma. In order to improve the coupling efficiency between the plasma and the induction coil, the magnetic field formed by the induction coil 120 needs to be concentrated inside the plasma.

The magnetic flux confinement unit 130 is disposed around the induction coil 120 to confine the magnetic flux generated by the induction coil and is formed of a magnetic body. The flux confinement unit 130 may be made of ferrite. The flux confinement unit 130 may generate heat loss due to a hysteresis loss and an induced current due to a magnetic field formed by the induction coil 120. When the magnetic flux confining part 130 is heated to a temperature equal to or higher than the Curie temperature, the magnetic flux confining part 130 may lose its characteristics. Accordingly, the flux confinement unit 130 can be heat-transferred by the thermally conductive cooling plate and cooled by the cooling pipe. When the thermally conductive cooling plate 132 is a conductive plate, the thermally conductive cooling plate may have a slit 132a so that no induction current flows.

The flux confinement unit 130 may include a plurality of magnetic block blocks 130a symmetrically disposed in a plane perpendicular to the center axis of the dielectric discharge tube 110. [ The magnetic block 130a may surround the outer surface, the upper surface, and the lower surface of the induction coil 120. The magnetic flux block 130a may be formed of a ferrite material. The magnetic flux confinement unit 130 can confine a magnetic field or magnetic flux to increase coupling efficiency. It can be seen that the plasma chamber resistance is increased by 50% when the flux confinement unit 130 is applied, compared to the case where the flux confinement unit 130 is not applied. As the actual resistance of the plasma increases, the magnitude of the current required to deliver the same power decreases and the efficiency (the ratio of power applied to the actual plasma) is also improved.

The magnetic block 130a has a "[" shape in cross section and may extend in the longitudinal direction. The magnetic block 130a is inserted to surround the induction coil 120 having a multi-layer structure, and the magnetic block 130a may be disposed symmetrically with respect to the center axis of the induction coil 120. [ In the case of increasing the number of the magnetic body blocks 130, the magnetic flux confinement efficiency is increased, but the self resistance (hysteresis loss) due to the ferrite is increased and the inductance can be increased.

The flux confinement unit 130 includes a magnetic block 130a disposed to surround the induction coil 120; A thermally conductive cooling plate 132 disposed on an outer surface of the magnetic block 130a to contact the magnetic block 130a to transfer heat of the magnetic block 130a, And a cooling pipe 134 for cooling the thermally conductive cooling plate. The thermally conductive cooling plate 132 may include a slit 132a for blocking the flow of the induction current generated by the induction coil 120. The thermally conductive cooling plate 132 may be formed of a conductor. In addition, the thermally conductive cooling plate 132 and the magnetic block 130a may be fixed by the thermally conductive paste 133.

The magnetic flux confinement unit according to the modified embodiment of the present invention may be arranged to surround the outer surface, the upper surface, and the lower surface of the induction coil, and may have a toroidal shape with the inner surface opened.

[Initial discharge structure]

Referring to US 7,622,693, a very high frequency plasma is used for the initial discharge. Microwave plasma discharge requires a complicated mechanical structure such as a waveguide, and the dielectric plate separating the waveguide and the discharge space is easily broken by the microwave plasma.

Referring to US 7,578,937, carbon arc discharge is used for initial discharge. However, since a pair of carbon electrodes is disposed in the discharge space, the supporting structure of the carbon electrode is complicated and easily damaged by the high temperature of the carbon electrode and the plasma. In particular, carbon electrodes are consumed in combination with oxygen during CF4 and CO2 discharge. Therefore, a new initial discharge structure is required.

According to one embodiment of the present invention, an initial discharge generating portion 150 is disposed around the dielectric discharge tube to provide an initial discharge.

3, the initial discharge generating unit 150 includes at least a pair of initial discharge electrodes 151 disposed on an outer surface of the dielectric discharge tube 110; And a DC power supply 129 for applying a DC high voltage between the pair of initial discharge electrodes 151; .

The initial discharge electrodes 151 may be spaced apart from each other with the induction coil 120 interposed therebetween in the direction of the center axis of the dielectric discharge tube 110. Specifically, the initial discharge electrodes 151 may be disposed on the upper and lower portions of the induction coil 120 in contact with the outer surface of the dielectric discharge tube 110, respectively. The DC power supply unit 152 may apply a DC high voltage to a pair of initial discharge electrodes disposed on the upper and lower portions of the induction coil 120, respectively. The DC power supply unit 152 may apply a high voltage pulse voltage of several kHz to several tens of kHz.

[Central Auxiliary Dielectric Tube for Heat Exchange]

9 is a view for explaining a plasma apparatus 100a according to another embodiment of the present invention.

Referring to FIGS. 3 and 9, the auxiliary dielectric tube 114 may be disposed at the center of the dielectric discharge tube 110. The gas can proceed inside the auxiliary dielectric tube 114. The auxiliary dielectric tube 114 is cylindrical in shape and may be quartz, ceramic, alumina, or sapphire. The auxiliary dielectric tube may receive heat generated by the plasma and use it for gas decomposition reaction. As a result, the thermal efficiency can be increased. Induction coil 420 produces an inductively coupled plasma.

When CH4 is passed through the plasma, the discharge is weakened and the plasma chamber resistance is reduced. In order to improve this, a structure for transferring the position of the gas discharged from the center nozzle after the induction coil was applied.

The auxiliary dielectric tube 114 is cylindrical in shape and the gas emitted by the center nozzle 145 in the auxiliary dielectric tube 114 can proceed. One end of the auxiliary dielectric tube 114 is coupled to the center of the swirl generating part 140 and the other end of the auxiliary dielectric tube 114 is disposed after a discharge area where plasma is generated.

The CO2 coming from the outer nozzle 143a is used for plasma discharge, and the CO2 is decomposed by the energy from the plasma and converted into CO, oxygen atoms, and heat. CH4, which is blown after the area of the induction coil 420 passing through the auxiliary dielectric tube 114, is separated into carbon and hydrogen molecules by absorbing the heat radiated from the plasma while passing through the auxiliary dielectric tube 114 The plasma discharge itself does not interfere. Then, carbon atoms ejected after passing through the auxiliary dielectric tube 114 react with oxygen atoms present on the outside to generate carbon monoxide. The advantage of this structure is that CH4 does not interfere with the plasma and the discharge does not deteriorate. In addition, the efficiency is improved because CH 4 does not take the energy of electrons and uses heat that is wasted to the periphery.

When the auxiliary dielectric tube 114 is applied, the plasma chamber resistance before and after CH4 injection is reduced. When the CH4-CO2 mixed gas is directly injected into the plasma, the room resistance is reduced by 30%. However, when the auxiliary dielectric tube 114 is applied, there is no change in the resistance of the plasma before and after CH4 injection. Thus, a stable plasma discharge is maintained.

10 is a graph showing experimental results of a plasma generating apparatus according to an embodiment of the present invention.

Referring to Fig. 10, the plasma apparatus of Fig. 3 was used. As the pressure increases to atmospheric pressure (760 Torr), the plasma resistance sharply decreases. When the plasma resistance is reduced, the AC power source must flow a large amount of current. Thus, when the plasma resistance is reduced, the plasma apparatus is substantially difficult to operate.

The plasma resistance when the magnetic flux confinement portion 130 is used is represented by a square. Plasma resistance in the case where two parallel laminated induction coils are used is represented by a triangle. On the other hand, the plasma resistance in the case where only the induction coil of the laminated structure is used is shown as a circle.

By using the induction coil of the laminated structure, plasma discharge is possible. Further, by adopting the parallel structure, the stability of the plasma discharge is improved by the increase of the plasma resistance and, in the case of using the flux confinement portion, the stability of the plasma discharge is improved by the increase of the plasma resistance.

11 is a graph showing experimental results of a plasma generating apparatus according to an embodiment of the present invention.

Referring to Figs. 9 and 11, experimental results using a laminated structure of the induction coil and the auxiliary dielectric tube 114 are shown. The plasma chamber resistance before and after the introduction of CH4 through the auxiliary dielectric tube 114 is indicated.

In the case of not injecting CH4 through the auxiliary dielectric tube 114, when the CH4-CO2 mixed gas is directly injected into the plasma, the plasma chamber resistance is reduced by 30%.

However, when CH4 is supplied through the auxiliary dielectric tube 114, the plasma chamber resistance before and after the introduction of CH4 hardly changes. Thus, the supply of methane gas through the supplemental dielectric tube improves discharge stability and process capability.

Hereinafter, atmospheric pressure plasma equipment for substrate processing will be described. When gases such as Ar, H 2, O 2, etc. are injected into the chamber by applying the electric energy while applying the gas alone or mixed according to the surface modification, the gas injected by the collision of the accelerated electrons is activated in the plasma state. Ions or radicals of gas generated in such a plasma state collide against the surface of the material to be treated to induce physicochemical change of the surface such as removal of a microfiltration film and formation of micro roughness, thereby improving various adhesive adhesion, prevention of defects in plastic injection coating, And serves to increase the coating adhesion. In addition, the atmospheric plasma can modify the surface of the material to be hydrophilic.

The atmospheric plasma apparatus can be applied to a display cleaning process, a deposition, a coating, and an etching process. Surface treatment with plasma can greatly improve production efficiency by eliminating contaminants and static electricity, increasing surface energy and improving adhesion.

Plasma spraying technology used in semiconductors and equipment is related to LCD and regeneration of components for manufacturing ceramic semiconductors. In particular, plasma coating parts are used to prevent peeling of coatings caused by fatal defects, By ensuring stable process conditions, the semiconductor manufacturing cost can be reduced and the yield can be improved.

12 is a view for explaining a plasma apparatus according to an embodiment of the present invention.

The description overlapping with that described in FIG. 3 will be omitted.

Referring to FIGS. 3 and 12, the plasma apparatus 200 includes a cylindrical dielectric discharge tube 110; An induction coil (420) disposed to surround the dielectric discharge tube (110) to generate an induction electric field to generate plasma in the dielectric discharge tube; A magnetic flux confinement unit (230) disposed around the induction coil to confine a magnetic field generated by the induction coil; And an AC power supply unit 129 for supplying power to the induction coil 420.

The plasma formed at atmospheric pressure or above atmospheric pressure can be provided directly to the object to be exposed in the atmosphere or to treat the object to be disposed in the processing chamber. The workpiece can be exposed directly or indirectly to the inductively coupled plasma. The object to be processed may be a semiconductor substrate, a glass substrate, a fiber, a metal, a ceramic, or the like. In the plasma apparatus, the object to be treated may be subjected to surface treatment such as hydrophilization treatment, cleaning treatment, and the like. The gas used may vary depending on the process to be treated, but may include argon, oxygen, nitrogen gas, and combinations thereof. In the case of plasma spraying treatment, an iron-based alloy powder may be additionally supplied. To move the object to be processed, a roller may be disposed. If the roller is a flat substrate, it may be changed to a susceptor.

The discharge gas provided to the dielectric discharge tube 110 may include at least one of argon, oxygen, and nitrogen. The discharge gas may be variously changed depending on the use of the process.

13 is a conceptual diagram illustrating a plasma system according to another embodiment of the present invention.

12 and 13, the plasma system 40 includes a gas supply unit 41, an inductively coupled plasma device 200 for supplying a source gas and a raw material from the gas supply unit 41 to perform inductive coupling discharge, And a substrate processing chamber 43 provided with gas decomposed in the inductively coupled plasma apparatus.

The inductively coupled plasma apparatus 200 includes a cylindrical dielectric discharge tube 110; An induction coil (420) disposed to surround the dielectric discharge tube to generate an induction electric field to generate plasma in the dielectric discharge tube; A magnetic flux confinement unit (230) disposed around the induction coil to confine a magnetic field generated by the induction coil; And an AC power supply 129 for supplying power to the induction coil. The inductively coupled plasma apparatus can perform a plasma discharge near atmospheric pressure.

The processing chamber 43 may further include a substrate processing gas supplier 44 for providing a separate substrate processing gas. The processing chamber 43 can be processed using only a substrate processing gas for substrate processing, or can perform substrate processing using only by-products of the inductively coupled plasma.

The processing chamber 43 may perform processes such as deposition, etching, cleaning, sterilization, surface treatment, and the like. The inductively coupled plasma device 200 may provide the process chamber 43 with a byproduct of the inductively coupled plasma directly or through the gas distribution portion 45.

For example, when the process chamber 43 performs a deposition process, the process chamber 43 may be contaminated by a deposition process. In order to clean the processing chamber, the inductively coupled plasma apparatus 200 may decompose the fluorine-containing gas such as NF 3 and provide it to the processing chamber 43. The process chamber may be cleaned by the gas provided from the inductively coupled plasma device. The process chamber may be evacuated to a vacuum by an exhaust pump.

The processing chamber 43 is not limited to a semiconductor substrate or a glass substrate, and can process various articles such as a film, a fiber, and a shoe.

14 is a conceptual diagram of a scrubber system according to another embodiment of the present invention.

Referring to FIG. 14, the scrubber system 90 may include a plasma generator 93, 95. The vacuum chamber 91 may perform a process such as etching or vapor deposition and exhaust the noxious gas through the high vacuum pump 92. The noxious gas can be exhausted to the outside through the low vacuum pump 94 and the wet scrubber 95. The plasma generator 95 is disposed between the low vacuum pump 94 and the wet scrubber 96 so that the harmful gas can be decomposed at a high pressure and supplied to the wet scrubber 96. The plasma generating device 95 may be an inductively coupled plasma device 400. On the other hand, a plasma generator 93 operating at a low pressure may be disposed between the high vacuum pump 92 and the low vacuum pump 94. The inductively coupled plasma generator 400 described above operates at a low pressure of several torr, and thus can be disposed in the exhaust pipe at the rear end of the high vacuum pump 92.

15A and 15B are conceptual diagrams illustrating a plasma generator according to another embodiment of the present invention. A description overlapping with those described in Figs. 3 and 12 will be omitted.

Referring to FIGS. 3, 15A and 15B, the plasma generator 400 includes a dielectric discharge tube 110; An induction coil 420 disposed to surround the dielectric discharge tube 110 to generate an induction electric field for generating plasma; And an AC power supply unit 129 for supplying power to the induction coil 420. The induction coil 420 includes a solenoid-shaped inner induction coil 422 arranged to surround the dielectric discharge tube 110; And an outer induction coil 424 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil 422 and the outer induction coil 424 are wound so that current flows in the same direction.

The dielectric discharge tube 110 may be supplied with a gas to be treated and may be maintained in a vacuum state under atmospheric pressure or atmospheric pressure. The dielectric discharge tube 110 may have a cylindrical shape with a diameter of several tens of centimeters. In order to maintain a stable discharge at atmospheric pressure or above atmospheric pressure, the supplied gas of the dielectric discharge tube may have a swirl flow. The dielectric discharge tube may be made of quartz or ceramics.

The induction coil 420 may be composed of a plurality of turns and the induction coil 420 may be a dual solenoide having a concentric axis. The induction coil may be disposed to surround the dielectric discharge tube 110 to generate a stable inductively coupled plasma in the dielectric discharge tube 110. For stable inductive coupling plasma discharge, the induction coil 420 maintains a proper impedance, a low voltage is applied to the induction coil, and a high current that generates a strong induction field can flow. In order to satisfy such a condition, an induction coil of a double solenoid structure having a concentric shaft is proposed. In order to suppress a decrease in discharge efficiency due to capacitive coupling at a position adjacent to the inner induction coil and the outer induction coil, positive voltages and negative voltages with opposite signs can be designed to face each other.

The induction coil 420 includes an inner induction coil 422 in the form of a solenoid wound to surround the cylindrical dielectric discharge tube 110 and an outer induction coil 424 in the form of a solenoid wound to surround the inner induction coil . The inner induction coil 422 has a predetermined radius and is formed of a plurality of helical-type turns, and the outer induction coil 424 can have a constant radius and be composed of a plurality of helical-type turns.

The inner induction coil 422 and the outer induction coil 424 may be electrically connected in series. The inner induction coil 422 may be inserted into the outer induction coil 424 to have a double solenoid structure having a concentric axis. The inner induction coil 422 and the outer induction coil 424 may be spaced apart from each other such that they are not in electrical contact with each other. To this end, the induction coil fixing unit (not shown) can fix the inner induction coil 422 and the outer induction coil 424 while maintaining a predetermined gap therebetween. The induction coil 420 may receive power directly from the AC power source or receive power through an impedance matching circuit or a transformer 428 for impedance matching.

One end of the inner induction coil 422 may be connected to one end of the secondary transformer coil 428b and one end of the outer induction coil 424 may be connected to the other end of the secondary transformer coil 428b. The other end of the inner induction coil 422 may be directly connected to the other end of the outer induction coil 424.

One end of the inner induction coil 422 may be disposed adjacent to one end of the outer induction coil 424. The other end of the inner induction coil 422 may be disposed adjacent to the other end of the outer induction coil 424. Accordingly, the inner induction coil 422 may be inserted into the outer induction coil 424, and may be disposed adjacent to and facing each other. Specifically, the induction coil may be formed by winding the inner induction coil and then winding the outer induction coil so as to be continuously superimposed on the inner induction coil.

The inner induction coil 422 and the outer induction coil 424 may be wound in an azimuthal direction and maintained at a constant distance from each other. Accordingly, the voltage of the inner induction coil 422 at the positions facing each other may have the same magnitude as the voltage of the outer induction coil 424 and have opposite signs. The voltage of the inner induction coil 422 may be opposite to the voltage 424 of the outer induction coil at positions facing each other. Such an induction coil generates a magnetic flux due to constructive interference, and the positive voltage and the negative voltage can be arranged to face each other. These positive and negative voltages arranged adjacent to each other are interpreted as operating as electric dipoles and screening electrostatic fields. As a result, the generation of streamers due to capacitive coupling can be suppressed, and the inductive coupling efficiency can be increased. Further, generation of parasitic charge coupled plasma can be suppressed, and discharge stability can be improved. The winding of the inner induction coil or the outer induction coil may be 4 to 9 times. The product of the winding angle of the inner induction coil and its sectional area may be equal to the product of the winding angle of the outer induction coil and its sectional area.

The AC power supply unit 129 can generate an AC voltage using a DC high voltage inverter. The AC power supply unit includes a first output terminal N1 and a second output terminal N2. The voltage of the first output terminal N1 is equal to the voltage of the second output terminal N2, Lt; / RTI > The driving frequency of the AC power supply 129 may be several hundred kHz to several MHz. The AC power supply unit may include a first output terminal and a second output terminal, and the first output terminal and the second output terminal may be directly connected to the induction coil. Or the AC power supply unit 129 may be connected to the induction coil through the transforming unit 428 for impedance matching.

The output of the AC power supply unit 129 is provided to the transforming unit 428. The transforming unit 428 may perform impedance matching. Specifically, the transformer 428 may include a primary transformer coil 428a and a secondary transformer coil 428b. The direction of the magnetic flux formed by the primary transformer coil 428a may be the same as the direction of the magnetic flux formed by the secondary transformer coil 428b.

In addition, the transforming unit 428 may include a reactance compensating capacitor 428c to cancel the reactance of the induction coil 420. [ The reactance compensating capacitor 428c, the induction coil 420, and the secondary transformer coil 428b constitute a resonance circuit, and the drive frequency may coincide with the resonance frequency of the resonance circuit. The reactance compensating capacitor 428c may be a fixed capacitor or a variable capacitor. Accordingly, the reactance component in the secondary transformer coil direction can be removed. The turns ratio of the first transforming coil 428a and the second transforming coil 428b can change the impedance. The winding ratio n2 / n1 of the winding n1 of the first transforming coil with respect to the winding n2 of the second transforming coil may be in the range of 1/3 to 1/2. The maximum power of the AC power source unit 129 may be changed according to the winding ratio n2 / n1. Preferably, the winding ratio can be set such that a large amount of current flows through the secondary transformer coil and a low voltage is induced.

The auxiliary inductor 428d may be connected in series to the primary transformer coil 428a of the transformer. The variable capacitor 428e may be connected in series to the primary transformer coil 428a of the transformer. The auxiliary inductor 428d may have a fixed inductance. The variable capacitor 428e may be varied in order to match the primary impedance of the transformer. The primary transformer coil 428a, the auxiliary inductor 428d and the variable capacitor 428e of the variable transformer connected in series can constitute a resonant circuit, and the resonant frequency of the resonant circuit is substantially equal to the drive frequency Can be matched.

The inductance of the inner induction coil 422 is larger than the inductance of the outer induction coil 424 in order to maintain the opposite sign voltage at positions where the inner induction coil 422 and the outer induction coil 424 face each other, &Lt; / RTI > The product of the winding of the inner induction coil 422 and its sectional area may be equal to the product of the winding of the outer induction coil 424 and its cross sectional area. Specifically, since the cross-sectional area of the outer induction coil is larger than the cross-sectional area of the inner induction coil, the winding of the inner induction coil may be larger than the winding of the outer induction coil. The winding of the inner induction coil or the outer induction coil may be 4 to 9 times. Specifically, the number of turns of the inner induction coil may be six, and the number of turns of the outer induction coil may be seven.

A parasitic discharge due to a high voltage may occur between the inner induction coil 422 and the outer induction coil 424 when the high induction coil 422 and the high induction coil 424 are close to each other. Thus, a material having a high dielectric strength to eliminate dielectric breakdown may be arranged to enclose the inner induction coil 424. Specifically, an arc prevention tube (not shown) may be inserted and disposed between the inner induction coil and the outer induction coil.

The induction coil and plasma that generate the inductively coupled plasma can be modeled as a transformer circuit. Accordingly, the inductively coupled plasma is referred to as a transformer coupled plasma. The induction coil 420 acts as the primary coil of the transformer circuit and the plasma can act as the secondary coil of the transformer circuit. A flux confining material such as a magnetic material may be used to increase the magnetic coupling between the induction coil 420 and the plasma. However, flux confinement materials are difficult to apply to dielectric discharge vessels of a cylindrical structure. Another way to increase magnetic coupling on the plasma with the induction coil 420 is to increase the inductance or winding of the induction coil. However, the increase of the inductance of the induction coil increases the impedance, which makes it difficult to efficiently transmit power. In addition, the increase of the inductance of the induction coil may increase the voltage applied to the induction coil, which may cause parasitic arc discharge. In addition, the high voltage applied to the induction coil causes capacitive coupling discharge and causes damage and thermal damage due to ion impact of the dielectric discharge vessel.

In order to form a high density plasma at atmospheric pressure, an induction coil structure capable of generating a high inductance and a high induction electric field is proposed. Further, at a driving frequency of several MHz or less, an impedance matching circuit uses a transformer. In this case, the load reactance of the secondary side output of the impedance matching transformer may be reduced using the reactance compensating capacitor 428c. In addition, the turn ratio of the primary transformer coil and the secondary transformer coil of the transformer can control the magnitude of the load impedance. Also, an auxiliary inductor and a variable capacitor may be used for the primary transformer coil of the transformer so that the impedance can be controlled.

According to one embodiment of the present invention, the induction coil 420 includes an inner induction coil 422 in the form of a solenoid and an outer induction coil 424 arranged to surround the inner induction coil 422. The induction coil 420 may have a two-layer structure having a concentric axis. That is, the inner induction coil can be inserted and aligned in the inner induction coil.

Further, in order to increase the inductance of the inner induction coil and the outer induction coil, the inner induction coil and the outer induction coil are overlapped and disposed so as to construct a constructive interference. In this case, a high voltage due to a high inductance is applied to both ends of the induction coil. However, the outer induction coil and the inner induction coil can be extended while winding the dielectric discharge tube in a helical form while facing each other at a predetermined interval. Accordingly, the voltages of the inner induction coil and the voltages of the outer induction coil may have opposite signs at the same position. This voltage distribution can be modeled as an electric dipole. The electric dipole generates an electric field at a close position, but as the distance increases, the intensity of the electric field rapidly decreases, thereby providing a screening effect. Therefore, the structure of the induction coil can increase the inductively coupled plasma efficiency by suppressing the generation of capacitive coupling plasma by the electrostatic field and increasing the inductance. The ions generated by the capacitively coupled plasma can damage the dielectric discharge tube and damage it.

Meanwhile, the secondary side of the transformer may include an induction coil 420 and a reactance compensating capacitor 428c. The secondary transformer coil of the transformer, the induction coil, and the reactance compensating capacitor may substantially constitute a resonant circuit, and the resonant frequency of the resonant circuit may be the same as the driving frequency of the AC power source. Thus, stable impedance matching can be performed.

Referring again to FIGS. 9 and 12, the swirl generator 140 may provide a swirl flow to the dielectric discharge tube 110. The swirl generator 140 is disposed at one end of the dielectric discharge tube 110 to seal the dielectric discharge tube and provide a fluid velocity component in an azimuthal direction in a cylindrical coordinate system to generate a pressure difference in the radial direction of the dielectric discharge tube . The plasma generated by the induction coil can be prevented from contacting the side wall of the dielectric discharge tube. The swirl generator 140 may provide a velocity component in the direction of the fluid azimuth that advances through the dielectric tube to provide concentration of the induction plasma. Therefore, thermal contact between the plasma and the dielectric discharge tube can be suppressed.

The swirl generator 140 includes an outer nozzle 143a that is formed to have a tangential component periodically on a circumference of a predetermined radius along the inner wall of the dielectric discharge tube to provide swirl flow. And an inner nozzle 144a which is formed to have a tangential component periodically on the circumference of a constant radius on the inside of the outer nozzle to provide a swirl flow. The swirl guide 112 is disposed between the inner nozzle and the outer nozzle, extends in the longitudinal direction of the dielectric discharge tube, is made of a dielectric material, and can have a cylindrical shape.

The swirl generator 140 may include an outer injector unit that provides a flow velocity in azimuthal direction components in a cylindrical coordinate system, one end of the dielectric discharge tube is coupled and includes a plurality of outer nozzles; An outer supporter coupled with the outer injector to provide an outer buffer space; An outer enclosure for sealing the outer buffer space by engaging with the outer support; An inner support inserted into the outer enclosure and providing an inner buffer space; And an inner injector portion which provides a flow rate of azimuthal direction components and is inserted into the inner support portion to seal the inner buffer space and includes a plurality of inner nozzles. The outer nozzle may be connected to the outer buffer space, and the inner nozzle may be connected to the inner buffer space.

The swirl generator 140 may further include a central injector portion injected into the inner injector portion and discharging the gas through the through hole formed at the center without swirl flow. The outer nozzle may be formed in a helical shape while rotating in the azimuthal direction on a circumference having a predetermined radius, in the longitudinal direction of the dielectric discharge tube. The inner nozzle may be formed in a helical shape while rotating in the azimuth direction on a circumference having a predetermined radius, in the longitudinal direction of the dielectric discharge tube.

The swirling guide may be disposed between the inner nozzle and the outer nozzle and may have a dielectric cylindrical shape extending in the longitudinal direction of the dielectric discharge tube. The swirl guide may be inserted between the inner support portion and the outer support portion.

The initial discharge generating part 150 may be disposed around the dielectric discharge tube to provide an initial discharge. The initial discharge generating unit includes a plurality of initial discharge electrodes 151 disposed along the outer surface of the dielectric discharge tube; And a high voltage power source 152 for applying a high voltage to the initial discharge electrode.

The magnetic flux confinement unit 230 may be formed of a magnetic material disposed around the induction coil to confine the magnetic flux generated by the induction coil. Wherein the magnetic flux confinement portion includes a plurality of magnetic block blocks symmetrically disposed in a plane perpendicular to a center axis of the dielectric discharge tube, the magnetic block block surrounds the outer surface, the upper surface, and the lower surface of the induction coil . The flux confinement unit may increase plasma coupling efficiency between the induction coil and the plasma.

The magnetic flux confinement unit 230 includes a magnetic block disposed to surround the induction coil; A thermally conductive plate formed of a nonmagnetic material arranged to surround the magnetic block so as to transmit heat of the magnetic block in contact with the magnetic block; And a cooling pipe fixed to the thermally conductive plate to cool the thermally conductive plate. The heat conduction plate may include a slit for blocking the flow of the induction current generated by the induction coil.

The auxiliary dielectric tube 114 may be disposed at the center of the dielectric discharge tube 112. The auxiliary dielectric tube may provide a gas at a plasma generating position to perform an endothermic reaction to efficiently utilize the heat generated in the plasma. Accordingly, the gas provided by the swirl generator generates a stable plasma, and the gas provided by the auxiliary dielectric tube can provide an efficient chemical reaction using the heat generated in the plasma. The auxiliary dielectric tube 114 may guide the flow of gas in the azimuthal direction to the region where the induction coil is disposed. In addition, when the gas flowing inside and outside the auxiliary dielectric tube is the same, the auxiliary dielectric tube can smoothly provide the swirl flow in the azimuthal direction.

16A and 16B are conceptual diagrams illustrating a plasma generating apparatus according to another embodiment of the present invention.

Referring to FIGS. 12, 16A and 16B, the plasma generator 500 includes a dielectric discharge tube 110; An induction coil 520 disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit 129 for supplying power to the induction coil 520; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 520 includes an inner induction coil 522 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 524 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

The transformer 428 may include a reactance compensating capacitor 428c connected in series with the secondary transformer coil of the transformer. The reactance compensating capacitor may be set to remove a reactance component due to the induction coil. Accordingly, the transforming unit can perform impedance matching. Specifically, the transforming portion 428 may include a primary transforming coil and a secondary transforming coil. The transforming unit 428 may include a reactance compensating capacitor 428c to cancel the reactance of the induction coil 520. [ The reactance compensating capacitor and the induction coil constitute a resonance circuit, and the drive frequency may coincide with the resonance frequency of the resonance circuit. The reactance compensating capacitor may be a fixed capacitor or a variable capacitor.

In order to reduce the voltage applied to the induction coil 520, voltage distribution capacitors 526a and 526b may be disposed symmetrically on the induction coil. Accordingly, the voltage distribution capacitors 526a and 526b can reduce a relatively applied voltage applied to the induction coil. The voltage-dividing capacitors (526a, 526b) include a first voltage-dividing capacitor (526a) connected in series to one end of a secondary transformer coil of the transformer; And a second voltage distribution capacitor 526b connected in series to the other end of the secondary transformer coil of the transformer. The first voltage distribution capacitor 526a may be connected to the inner induction coil 522 and the second voltage distribution capacitor 526b may be connected to the outer induction coil 524. [

According to an embodiment of the present invention, in order to reduce the voltage applied to the induction coil, the induction coil can be voltage-divided using a capacitor. Specifically, voltage distribution capacitors may be disposed at both ends of the induction coil, respectively. Thus, the electrostatic field due to the screening effect is reduced, and the voltage induced in the induction coil can be reduced by the voltage distribution model. The secondary side of the transformer may also include an induction coil, a reactance compensating capacitor, and a voltage distribution capacitor. The secondary transformer coil, the induction coil, the reactance compensating capacitor, and the voltage distribution capacitor of the transformer substantially constitute a resonance circuit, and the resonance frequency of the resonance circuit may be equal to the drive frequency of the AC power source. Accordingly, in a state where a low voltage is applied to the induction coil, stable impedance matching can be performed.

The sum (Cb + Cr) of the capacitance (Cb) of the second voltage-dividing capacitor and the capacitance (Cr) of the reactance compensating capacitor may be set to be equal to the capacitance (Ca) of the first voltage-sharing capacitor. Thus, a symmetrical voltage distribution can be provided to the induction coil.

17 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.

Referring to FIG. 17, the plasma generator 500a includes a dielectric discharge tube 110; An induction coil 520 disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit 129 for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 520 includes an inner induction coil 522 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 524 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

The auxiliary induction coil 620 may be disposed in the center axis direction of the induction coil 520 and the dielectric discharge tube and may be disposed to surround the dielectric discharge tube to generate an induced electric field to generate plasma. The auxiliary induction coil may have the same structure as the induction coil and may have a plurality of auxiliary induction coils. The induction coil and the auxiliary induction coil may be connected in series. The first impedance canceling capacitor 521 may be disposed between the induction coil 520 and the auxiliary induction coil 620 connected in series.

The auxiliary induction coil 620 includes an inner auxiliary induction coil 622 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer auxiliary induction coil 624 in the form of a solenoid which is electrically connected in series with the inner auxiliary induction coil and overlaps and surrounds the inner auxiliary induction coil.

In order to reduce the imaginary part of the impedance of the induction coil and the auxiliary induction coil, a first impedance cancellation capacitor 521 may be disposed between the induction coil and the auxiliary induction coil connected in series. The auxiliary induction coil may have the same shape as the induction coil. The auxiliary induction coil may be spaced apart from the induction coil to surround the dielectric discharge tube.

When there are a plurality of auxiliary induction coils, the auxiliary induction coils may be connected to each other in series. The second impedance canceling capacitors (not shown) may be disposed between the adjoining auxiliary induction coils, respectively. The second impedance canceling capacitor may cancel the imaginary part of the impedance of the auxiliary coils.

18A and 18B are conceptual diagrams illustrating a plasma generating apparatus according to another embodiment of the present invention.

18A and 18B, the plasma generator 500b includes a dielectric discharge tube 110; An induction coil 520 disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit (428) for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 520 includes an inner induction coil 522 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 524 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

In order to reduce the voltage applied to the induction coil, voltage distribution capacitors 526a and 526b may be arranged symmetrically in the induction coil. Accordingly, the voltage distribution capacitor can reduce a relatively applied voltage applied to the induction coil. The voltage distribution capacitor includes a first voltage distribution capacitor (526a) connected in series to one end of a secondary transformer coil of the transformer; And a second voltage distribution capacitor 526b connected in series to the other end of the secondary transformer coil of the transformer. The first voltage distribution capacitor may be connected to the inner induction coil, and the second voltage distribution capacitor may be connected to the outer induction coil.

The auxiliary voltage distribution capacitor 528 may connect the other end of the inner induction coil 522 and the other end of the outer induction coil 524. The capacitance of the auxiliary voltage distribution capacitor 528 may be about 1/2 of the capacitance of the first voltage distribution capacitor 526a. Also, the capacitance of the auxiliary voltage distribution capacitor may be about 1/2 of the capacitance of the second voltage distribution capacitor 526b.

19A and 19B are conceptual diagrams illustrating a plasma generating apparatus according to another embodiment of the present invention.

19A and 19B, the atmospheric-pressure plasma generator 500c includes a dielectric discharge tube 110; An induction coil 520 disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit 129 for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 520 includes an inner induction coil 522 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 524 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

In order to reduce the voltage applied to the induction coil, voltage distribution capacitors 526a and 526b may be arranged symmetrically in the induction coil. Accordingly, the voltage distribution capacitor can reduce a relatively applied voltage applied to the induction coil. Wherein the voltage distribution capacitor comprises: a first voltage distribution capacitor connected in series to one end of a secondary transformer coil of the transformer; And a second voltage distribution capacitor connected in series to the other end of the secondary transformer coil of the transformer. The first voltage distribution capacitor may be connected to the inner induction coil, and the second voltage distribution capacitor may be connected to the outer induction coil.

The first auxiliary voltage distribution capacitor 529a may be disposed between the other end of the inner induction coil 522 and the ground. The second auxiliary voltage distribution capacitor 529b may be disposed between the other end of the outer induction coil 524 and the ground. One end of the first auxiliary voltage accumulator 529a may be commonly connected between one end of the second auxiliary voltage accumulator 529b and the ground. The electrostatic capacity of the first auxiliary voltage distribution capacitor may be substantially equal to the electrostatic capacity of the second auxiliary voltage distribution capacitor. In addition, the capacitance of the first voltage distribution capacitor may be substantially equal to the capacitance of the second voltage distribution capacitor.

20 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.

Referring to FIG. 20, the atmospheric pressure plasma generator 500d includes a dielectric discharge tube 110; An induction coil 520 disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit 129 for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 520 includes an inner induction coil 522 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 524 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

The AC power supply unit 129 may be directly connected to the induction coil 520. A first voltage distribution capacitor 526a may be disposed between the first output terminal of the AC power source and one end of the inner induction coil. A second voltage distribution capacitor 526b may be disposed between the second output terminal of the AC power source and one end of the outer induction coil.

21 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.

Referring to FIG. 21, the atmospheric-pressure plasma generator 500e includes a dielectric discharge tube 110; An induction coil 520 disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit 129 for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 520 includes an inner induction coil 522 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 524 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

The auxiliary induction coil 620 is disposed in the center axis direction of the induction coil and the dielectric discharge tube. The auxiliary induction coil 620 includes an auxiliary inside induction coil 622 and an auxiliary outside induction coil 624 arranged to surround the auxiliary inside induction coil 622. The inner induction coil 522, the auxiliary inner induction coil 622, the auxiliary outer induction coil 624, and the outer induction coil 524 are sequentially connected in series.

One end of the inner induction coil 522 is connected to one end of the AC power source unit 129 and one end of the outer induction coil 524 is connected to the other end of the AC power source unit.

The first auxiliary voltage distribution capacitor 629a may connect the other end of the inner induction coil and one end of the auxiliary inner induction coil. The second auxiliary voltage distribution capacitor 629b may connect the other end of the auxiliary inside induction coil and one end of the auxiliary outside induction coil. The third auxiliary voltage distribution capacitor 629c may connect the other end of the auxiliary outer induction coil and the other end of the outer induction coil.

22 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.

22, the atmospheric-pressure plasma generator 700 includes a dielectric discharge tube 110; An induction coil (720) disposed to surround the dielectric discharge tube to generate an induction field to generate plasma; An AC power supply unit 129 for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 720 includes an inner induction coil 522 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 524 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

The first auxiliary outer induction coil 726 may be disposed so as to surround the outer induction coil 724. The second auxiliary outer induction coil 728 may be disposed to surround the first auxiliary outer induction coil 726. One end of the inner induction coil 722 may be connected to one end of the AC power source unit 129 and one end of the second auxiliary outer induction coil 728 may be connected to the other end of the AC power source unit 129.

The inner induction coil 722, the outer induction coil 724, the first auxiliary outer induction coil 726, and the second auxiliary outer induction coil 728 may be serially serially connected. The first to third auxiliary voltage distribution capacitors 729a, 729b and 729c are connected to the inner induction coil 722, the outer induction coil 724, the first auxiliary outer induction coil 726, Induction coils 728, respectively. The first auxiliary voltage distribution capacitor 729a may be disposed between the inner induction coil 722 and the outer induction coil 724. A second auxiliary voltage distribution capacitor 729b may be disposed between the outer induction coil 724 and the first auxiliary outer induction coil 726. [ A third auxiliary voltage distribution capacitor 729c may be disposed between the first auxiliary outer induction coil 726 and the second auxiliary outer induction coil 728. [

23 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.

23, the atmospheric-pressure plasma generator 800a includes a dielectric discharge tube 110; An induction coil (420) disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit 129 for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 420 includes an inner induction coil 422 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 424 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

At least one auxiliary induction coil 820a to 820i is disposed in the center axis direction of the induction coil 420 and the dielectric discharge tube and is disposed to surround the dielectric discharge tube 110 to generate an induction electric field .

Each of the auxiliary induction coils 820a to 820i includes an inner auxiliary induction coil 822 in the form of a solenoid disposed to surround the dielectric discharge tube 110; And an outer auxiliary induction coil 824 in the form of a solenoid which is electrically connected in series with the inner auxiliary induction coil and overlapped to surround the inner auxiliary induction coil. The inner induction coil 422 and the outer induction coil 424 are connected in series through a first capacitor 829a and the outer induction coil 422 and the auxiliary inner induction coil 822 are connected in series through a second capacitor 829b And the auxiliary inner induction coil 822 and the auxiliary outer induction coil 824 are electrically connected in series through the third capacitor 829c.

24 is a conceptual diagram illustrating a plasma generating apparatus according to another embodiment of the present invention.

Referring to FIG. 24, the atmospheric-pressure plasma generator 800b includes a dielectric discharge tube 110; An induction coil (420) disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; An AC power supply unit 129 for supplying power to the induction coil; And a transformer 428 including a primary transformer coil and a secondary transformer coil for transmitting the power of the AC power source to the induction coil. The induction coil 420 includes an inner induction coil 422 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer induction coil 424 in the form of a solenoid superposed to surround the inner induction coil. The inner induction coil and the outer induction coil are wound so as to flow current in the same direction.

Each of the auxiliary induction coils 820a to 820i includes an inner auxiliary induction coil 822 in the form of a solenoid disposed to surround the dielectric discharge tube; And an outer auxiliary induction coil 824 in the form of a solenoid which is electrically connected in series with the inner auxiliary induction coil and overlapped to surround the inner auxiliary induction coil. The inner induction coil 422 and the auxiliary inner induction coil 822 are connected in series through a first capacitor 929a and the outer induction coil 424 and the auxiliary outer induction coil 824 are connected in series to each other through a second capacitor 929b.

The auxiliary outer induction coil 824 of the auxiliary induction coil disposed at the lowermost end of the auxiliary inside induction coil 822 of the auxiliary induction coil 820i disposed at the lowermost stage can be connected in series via the third capacitor 929c.

25 is an experimental result showing plasma holding power according to a pressure according to an embodiment of the present invention.

Referring to Fig. 25, the result is shown in Fig. 25, in which the inner induction coil has 7 turns and the outer induction coil has 7 turns, and an induction coil (in- ractance of 13.6 uH) and a voltage distribution capacitor are used. The circular shape is the result of the inner induction coil having 5.5 turns, the outer induction coil having 5.5 turns, and the induction coil (inductance of 10.5 uH) placed in superposition with each other and the voltage distribution capacitor not being used. The reverse triangle shows a case in which two 4-turn three-layer structure induction coils are connected in parallel (inductance of 8.6 uH). A two-layer structure (Halloween) that eliminates capacitive coupling effects with a voltage-sharing capacitor reduces the minimum discharge sustained power by more than a few percent at atmospheric pressure (760 Torr). Thus, the use of induction coil structures and voltage-sharing capacitors can increase discharge efficiency.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And all of the various forms of embodiments that can be practiced without departing from the technical spirit.

110: dielectric discharge tube
120: induction coil
130: flux confinement
140: Swirl generator
420: induction coil

Claims

Dielectric discharge tubes;
An induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; And
And an AC power supply unit for supplying power to the induction coil,
Wherein the induction coil comprises:
An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And an outer induction coil in the form of a solenoid superposed to surround the inner induction coil,
The inner induction coil and the outer induction coil are wound so as to flow current in the same direction,
Wherein the AC power supply unit includes a first output terminal and a second output terminal,
The potential of the first output terminal is opposite to the potential of the second output terminal,
Wherein the potentials at the closest positions of the inner induction coil and the outer induction coil are opposite to each other and equal in magnitude to ground.

The method according to claim 1,
Further comprising a transformer portion for transmitting the power of the AC power source to the induction coil and including a primary transformer coil and a secondary transformer coil.

3. The method of claim 2,
One end of the secondary transformer coil is connected to one end of the inner induction coil,
The other end of the secondary transformer coil is connected to one end of the outer induction coil,
And one end of the inner induction coil and one end of the outer induction coil are disposed adjacent to each other.

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Dielectric discharge tubes;
An induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; And
And an AC power supply unit for supplying power to the induction coil,
Wherein the induction coil comprises:
An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And an outer induction coil in the form of a solenoid superposed to surround the inner induction coil,
The inner induction coil and the outer induction coil are wound so as to flow current in the same direction,
Further comprising a transformer portion that transmits power of the AC power source to the induction coil and includes a primary transformer coil and a secondary transformer coil,
Wherein the transformer further comprises a reactance compensating capacitor connected in series to a secondary transformer coil of the transformer,
And the reactance compensating capacitor is set to cancel the reactance component of the induction coil.

3. The method of claim 2,
A first voltage distribution capacitor connected in series to one end of a secondary transformer coil of the transformer; And
Further comprising a second voltage distribution capacitor connected in series to the other end of the secondary transformer coil of the transforming unit,
The first voltage-dividing capacitor is connected to one end of a secondary transformer coil of the transforming unit and one end of the inner induction coil,
Wherein the second voltage-dividing capacitor is connected to the other end of the secondary transformer coil of the transforming unit and to one end of the outer induction coil.

The method according to claim 6,
Further comprising an auxiliary voltage distribution capacitor connecting the other end of the inner induction coil and the other end of the outer induction coil.

The method according to claim 1,
One end of the inner induction coil is connected to one end of the AC power source,
One end of the outer induction coil is connected to the other end of the AC power source,
Further comprising an auxiliary voltage distribution capacitor connecting the other end of the inner induction coil and the other end of the outer induction coil.

Dielectric discharge tubes;
An induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; And
And an AC power supply unit for supplying power to the induction coil,
Wherein the induction coil comprises:
An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And an outer induction coil in the form of a solenoid superposed to surround the inner induction coil,
The inner induction coil and the outer induction coil are wound so as to flow current in the same direction,
One end of the inner induction coil is connected to one end of the AC power source,
One end of the outer induction coil is connected to the other end of the AC power source,
A first auxiliary voltage distribution capacitor disposed between the other end of the inner induction coil and the ground; And
Further comprising a second auxiliary voltage distribution capacitor disposed between the other end of the outer induction coil and the ground,
The first auxiliary voltage distribution capacitor is directly connected between the inner induction coil and the ground,
The second auxiliary voltage distribution capacitor is directly connected between the outer induction coil and the ground,
Wherein one end of the first auxiliary voltage capacitor is commonly connected between one end of the second auxiliary voltage capacitor and the ground.

The method according to claim 1,
Further comprising at least one or more auxiliary induction coils disposed to be spaced apart from each other in the direction of the central axis of the induction coil and the dielectric discharge tube and arranged to surround the dielectric discharge tube to generate an induction electric field for generating plasma,
The auxiliary induction coil comprises:
An inner auxiliary induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And a solenoid-type outer auxiliary induction coil electrically connected in series with the inner auxiliary induction coil and disposed so as to overlap the inner auxiliary induction coil,
Wherein the induction coil and the auxiliary induction coil are electrically connected in series.

11. The method of claim 10,
A first impedance canceling capacitor disposed between the induction coil and the auxiliary induction coil; And
And a second impedance canceling capacitor disposed between the auxiliary induction coils,
The first impedance canceling capacitor cancels the imaginary part of the impedance of the induction coil and the auxiliary induction coil,
And the second impedance canceling capacitor cancels the imaginary part of the impedance of the auxiliary induction coils.

Dielectric discharge tubes;
An induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; And
And an AC power supply unit for supplying power to the induction coil,
Wherein the induction coil comprises:
An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And an outer induction coil in the form of a solenoid superposed to surround the inner induction coil,
The inner induction coil and the outer induction coil are wound so as to flow current in the same direction,
Further comprising at least one or more auxiliary induction coils disposed to be spaced apart from each other in the direction of the central axis of the induction coil and the dielectric discharge tube and arranged to surround the dielectric discharge tube to generate an induction electric field for generating plasma,
The auxiliary induction coil comprises:
An inner auxiliary induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And a solenoid-type outer auxiliary induction coil electrically connected in series with the inner auxiliary induction coil and disposed so as to overlap the inner auxiliary induction coil,
The inner induction coil and the outer induction coil are connected in series through the first capacitor,
Wherein the outer induction coil and the inner auxiliary induction coil are connected in series through a second capacitor,
Wherein the inner auxiliary induction coil and the outer auxiliary induction coil are electrically connected in series through a third capacitor.

The method according to claim 1,
Further comprising at least one or more auxiliary induction coils disposed to be spaced apart from each other in the direction of the central axis of the induction coil and the dielectric discharge tube and arranged to surround the dielectric discharge tube to generate an induction electric field for generating plasma,
The auxiliary induction coil comprises:
An inner auxiliary induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And a solenoid-type outer auxiliary induction coil electrically connected in series with the inner auxiliary induction coil and disposed so as to overlap the inner auxiliary induction coil,
The inner induction coil and the inner auxiliary induction coil are connected in series through the first capacitor,
Wherein the outer induction coil and the outer auxiliary induction coil are connected in series through a second capacitor,
And the inner auxiliary induction coil of the auxiliary induction coil disposed at the lowermost stage is connected in series through the external auxiliary induction coil of the auxiliary induction coil disposed at the lowermost stage and the third capacitor.

3. The method of claim 2,
An auxiliary inductor connected in series to the primary transformer coil of the transformer; And
Further comprising a variable capacitor connected in series to the primary transformer coil of the transforming unit.

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Dielectric discharge tubes;
An induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating plasma; And
And an AC power supply unit for supplying power to the induction coil,
Wherein the induction coil comprises:
An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And an outer induction coil in the form of a solenoid superposed to surround the inner induction coil,
The inner induction coil and the outer induction coil are wound so as to flow current in the same direction,
A first auxiliary outer induction coil arranged to surround the outer induction coil; And
And a second auxiliary outer induction coil disposed to surround the first auxiliary outer induction coil.

30. The method of claim 29, wherein
One end of the inner induction coil is connected to one end of the AC power source,
One end of the second auxiliary outer induction coil is connected to the other end of the AC power source,
Wherein the inner induction coil, the outer induction coil, the first auxiliary outer induction coil, and the second auxiliary outer induction coil are serially connected in sequence,
Further comprising first to third auxiliary voltage distribution capacitors disposed between the inner induction coil, the outer induction coil, the first auxiliary outer induction coil, and the second auxiliary outer induction coil, respectively, Device.

The method of claim 1, wherein
Further comprising an auxiliary induction coil disposed so as to be spaced apart from a center axis of the induction coil and the dielectric discharge tube,
Wherein the auxiliary induction coil includes an inner auxiliary induction coil and an outer auxiliary induction coil arranged to surround the inner auxiliary induction coil,
Wherein the inner induction coil, the inner auxiliary induction coil, the outer auxiliary induction coil, and the outer induction coil are sequentially connected in series.

32. The method of claim 31, wherein
One end of the inner induction coil is connected to one end of the AC power source,
One end of the outer induction coil is connected to the other end of the AC power source,
A first auxiliary voltage distribution capacitor connecting the other end of the inner induction coil and one end of the inner auxiliary induction coil;
A second auxiliary voltage distribution capacitor connecting the other end of the inner auxiliary induction coil and one end of the outer auxiliary induction coil; And
Further comprising a third auxiliary voltage distribution capacitor connecting the other end of the outer auxiliary induction coil and the other end of the outer induction coil.

A dielectric discharge tube providing a flow of process gas; And
And an induction coil disposed to surround the dielectric discharge tube to generate an induction field for generating an inductively coupled plasma,
Wherein the induction coil comprises:
An inner induction coil in the form of a solenoid disposed to surround the dielectric discharge tube; And
And an outer induction coil in the form of a solenoid which is connected in series with the inner induction coil while being wound in a continuous fashion and overlapped to surround the inner induction coil,
The inner induction coil and the outer induction coil are wound so as to flow current in the same direction,
Wherein the potentials at the closest positions of the inner induction coil and the outer induction coil are opposite to each other and equal in magnitude to ground.

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