阅读说明：本技术 氮氧化物减少设备和气体处理设备 (Nitrogen oxide reduction apparatus and gas treatment apparatus ) 是由 崔奫修 高燦奎 S.马尼 于 2017-12-28 设计创作，主要内容包括：本公开提供一种气体处理设备,所述气体处理设备包括：反应室,其被构造成通过等离子体处理从外部供应的气体,该经处理的气体包含氮氧化物；以及氮氧化物减少设备,其连接到反应室。氮氧化物减少设备包括冷却单元,该冷却单元被构造成将经处理的气体冷却到低于氮氧化物产生温度的温度。(The present disclosure provides a gas treatment apparatus, comprising: a reaction chamber configured to process a gas supplied from the outside by plasma, the processed gas including nitrogen oxide; and a nitrogen oxide reduction device connected to the reaction chamber. The nitrogen oxide reduction apparatus includes a cooling unit configured to cool the treated gas to a temperature below a nitrogen oxide generation temperature.)

1. A gas treatment apparatus, comprising:

a reaction chamber configured to process a gas supplied from the outside by plasma, the processed gas including nitrogen oxide; and

a nitrogen oxide reduction device connected to the reaction chamber,

wherein the nitrogen oxide reduction apparatus includes a cooling unit configured to cool the treated gas to a temperature below a nitrogen oxide generation temperature.

2. The gas processing apparatus of claim 1, wherein the cooling unit includes one or more gas injection nozzles configured to inject a cryogenic gas.

3. The gas treatment apparatus according to claim 2, wherein the gas injection nozzles are provided at a plurality of positions of the nitrogen oxide reduction apparatus, and the low-temperature gas is an inert gas.

4. The gas treatment apparatus according to claim 2, wherein said nitrogen oxide reduction apparatus further comprises a cylindrical housing and an annular gas supply ring disposed inside said cylindrical housing, and

the one or more gas injection nozzles are disposed on the gas supply ring.

5. The gas processing apparatus of claim 3, wherein the inert gas comprises at least one of nitrogen and argon.

6. The gas processing apparatus of claim 1, wherein the cooling unit comprises a heat exchanger.

7. A nitrogen oxide reduction apparatus for reducing nitrogen oxide contained in a gas treated by plasma, the nitrogen oxide reduction apparatus comprising:

a cooling unit configured to cool the treated gas to a temperature below a nitrogen oxide generation temperature.

8. The nitrogen oxide-reducing apparatus of claim 7, wherein the cooling unit comprises one or more gas injection nozzles configured to inject a low temperature gas.

9. The nitrogen oxide-reducing apparatus according to claim 8, wherein the gas injection nozzles are provided at a plurality of positions of the nitrogen oxide-reducing apparatus, and the low-temperature gas is an inert gas.

10. The nitrogen oxide-reducing apparatus according to claim 8, further comprising a cylindrical housing and an annular gas supply ring disposed inside the cylindrical housing, and

the one or more gas injection nozzles are disposed on the gas supply ring.

11. The nitrogen oxide-reducing apparatus of claim 7, wherein the cooling unit comprises a heat exchanger.

12. A gas treatment apparatus, comprising:

a plasma generating apparatus configured to generate plasma;

a reaction chamber connected to the plasma generating apparatus and configured to process a gas supplied from the outside by plasma, the processed gas containing nitrogen oxide; and

a nitrogen oxide reduction device connected to the reaction chamber,

wherein the nitrogen oxide reduction apparatus includes a cooling unit configured to cool the treated gas to a temperature below a nitrogen oxide generation temperature.

13. The gas treatment plant of claim 12 further comprising a conduit having water injection nozzles,

wherein the nitrogen oxide reduction apparatus is positioned between the reaction chamber and the conduit.

14. The gas processing apparatus of claim 13, wherein the plasma generation apparatus comprises:

a cathode assembly comprising a cathode;

an anode assembly comprising an anode, the anode assembly having a plasma generating space therein; and

one or more magnetic force generators configured to generate a magnetic force,

wherein the anode assembly has: an end portion in which a gas supply path is provided; and another end portion having an opening, the gas supply path being configured to supply a plasma generation gas to the plasma generation space, and

wherein the gas supply path is configured to generate a vortex of the plasma generation gas in the plasma generation space, and the one or more magnetic force generators are arranged such that the magnetic force is generated in a direction opposite to a rotation direction of the vortex of the plasma generation gas.

15. The gas processing apparatus of claim 14, wherein the one or more magnetic force generators are arranged such that the magnetic force is applied to an arc point generated between the cathode and the anode in a direction opposite to the rotational direction of the vortex of the plasma generation gas.

16. The gas treatment apparatus according to claim 14, wherein said one or more magnetic force generators are arranged such that polarities thereof become opposite to each other in a direction of an axis of said anode assembly.

17. The gas processing apparatus according to claim 16, wherein an N pole of the one or more magnetic force generators is directed toward the opening when the rotation direction of the vortex of the plasma generation gas is a counterclockwise direction and an S pole of the one or more magnetic force generators is directed toward the opening when the rotation direction of the vortex of the plasma generation gas is a clockwise direction, as viewed from the opening toward the gas supply path.

Technical Field

The present invention relates to a nitrogen oxide reduction apparatus and a gas treatment apparatus including the same.

Background

In the case of decomposing harmful gases by using a plasma generating apparatus, the harmful gases are treated at high temperatures, and this may generate nitrogen oxides. In particular, at high temperatures of about 800 ℃ or more, the amount of thermal NOx (nitrogen oxides) generated by reaction with the oxygen-containing reaction gas increases. Nitrogen oxides cause acid rain and photochemical smog, and are considered as one of the main air pollutants. Therefore, a technique capable of reducing nitrogen oxides is required.

Conventionally, catalytic devices or dilution devices are used to treat nitrogen oxides. However, these devices are not cost effective. As another solution, the use of oxygen-containing materials has been avoided to prevent the production of nitrogen oxides. However, in the case of decomposing harmful gases by using a material not containing oxygen, another toxic substance or other by-product is generated and deposited on the inner surface of the apparatus. Also, the harmful gas treatment efficiency is lowered.

(patent document 1) korean patent application publication No. 10-2008-.

Disclosure of Invention

Technical problem

In view of the above, it is an object of the present disclosure to provide a gas treatment apparatus and a nitrogen oxide reduction apparatus capable of reducing nitrogen oxides.

It is a further object of the present disclosure to provide a technique for improving the stability and durability of a plasma generating apparatus included in a gas processing apparatus.

Solution to the problem

In one embodiment of the present disclosure, a gas treatment apparatus includes: a reaction chamber configured to process a gas supplied from the outside by plasma, the processed gas including nitrogen oxide; and a nitrogen oxide reduction device connected to the reaction chamber. The nitrogen oxide reduction apparatus includes a cooling unit configured to cool the treated gas to a temperature below a nitrogen oxide generation temperature.

Advantageous effects of the invention

The nitrogen reduction apparatus and the gas treatment apparatus according to the embodiments of the present disclosure provide the following advantages: by rapidly cooling the plasma-treated gas to a temperature lower than the nitrogen oxide generation temperature using the cooling unit, nitrogen oxides are effectively reduced without reducing the harmful gas treatment efficiency.

The plasma generation apparatus included in the gas processing apparatus according to the embodiment of the present disclosure provides the following advantages: it is possible to stably generate plasma and improve the life span of the electrode by arranging the magnetic force generator to generate a force opposite to the rotational direction of the vortex of the plasma generation gas generated in the plasma generation space.

Drawings

Fig. 1 schematically shows a plasma generating apparatus according to one embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of the plasma generating apparatus taken along line ii-ii of fig. 1.

Fig. 3 is another cross-sectional view of the plasma generating apparatus taken along line iii-iii of fig. 1.

Fig. 4A is a cross-sectional view of the plasma generating apparatus taken along line iva-iva of fig. 1.

Fig. 4B is another cross-sectional view of the plasma generating apparatus taken along line ivb-ivb of fig. 1.

Fig. 5 is a direction of force applied to an anode arc point of a plasma generating apparatus according to an embodiment of the present disclosure.

Fig. 6 is a direction of force applied to an anode arc point of a plasma generating apparatus according to an embodiment of the present disclosure.

Fig. 7 schematically illustrates a plasma generating apparatus according to another embodiment of the present disclosure.

Fig. 8 schematically illustrates a plasma generating apparatus according to yet another embodiment of the present disclosure.

FIG. 9 illustrates a configuration of an anode assembly according to an embodiment of the present disclosure.

Fig. 10 schematically illustrates a gas treatment apparatus according to an embodiment of the present disclosure.

FIG. 11 illustrates a nitrogen oxides reduction apparatus according to an embodiment of the present disclosure.

Fig. 12 illustrates a gas supply ring according to an embodiment of the present disclosure.

FIG. 13 illustrates a nitrogen oxide reduction apparatus according to another embodiment of the present disclosure.

Detailed Description

Advantages and features of the present disclosure and methods of accomplishing the same will become apparent from the following description when taken in conjunction with the accompanying drawings. However, the embodiments are not limited to the described embodiments, as the embodiments may be embodied in various forms. It should be noted that the present embodiments are provided so that this disclosure will be thorough and will also allow those skilled in the art to know the full scope of the embodiments. Accordingly, the embodiments are to be limited only by the scope of the following claims.

In describing the embodiments of the present disclosure, if it is determined that detailed description of related known components or functions unnecessarily obscures the gist of the present disclosure, detailed description thereof will be omitted. Further, terms to be described below are defined in consideration of functions of embodiments of the present disclosure, and may vary according to intention or practice of a user or operator. Therefore, it can be defined based on the contents throughout the specification.

Fig. 1 schematically illustrates a plasma generation apparatus according to an embodiment of the present disclosure. The plasma generating device may be a plasma torch.

The plasma generating apparatus includes: a cathode assembly 100 for generating arc discharge by a high voltage applied thereto; an anode assembly 200 for generating plasma having a temperature of 1000 ℃ or more in a plasma generation space S formed by arc discharge between the anode assembly 200 and the cathode assembly 100; a gas introduction line (plasma generation gas introduction line) 300 for supplying a plasma generation gas to the plasma generation space S; and a magnetic force generator 220 for generating a magnetic force in the plasma generation space S.

The cathode assembly 100 will be described in detail below.

The cathode assembly 100 has a cathode 110 to which a high voltage is applied at a lower portion thereof. Further, the cathode assembly 100 may have a path therein through which cooling water flows. The cooling water path extends to the cathode 110 and allows efficient cooling of the high temperature cathode 110 during operation of the cathode assembly 100. Therefore, abrasion of the cathode 110 can be prevented.

Preferably, the cathode 110 is made of hafnium or tungsten with thorium or yttrium added thereto. However, the cathode 110 may comprise another metal.

As shown in fig. 1, one end portion of the cathode assembly 100 is positioned outside the anode assembly 200, and the other end portion of the cathode assembly 100 (i.e., the side where the cathode 110 is provided) is coupled with the anode assembly 200 to be located in the plasma generation space S of the anode assembly 200.

An insulator 400 is interposed between the cathode assembly 100 and the anode assembly 200. Accordingly, the cathode assembly 100 and the anode assembly 200 are insulated from each other.

Next, the anode assembly 200 will be described in detail below.

The anode assembly 200 is formed in a cylindrical shape such that the plasma generating space S can be formed therein while surrounding the cathode 110 of the cathode assembly 100. The anode assembly 200 includes an anode 210 for generating plasma between the anode 210 and the cathode 110 by applying a high voltage to the cathode 110.

In other words, the anode assembly 200 has a plasma generation space S therein, in which plasma is generated by DC arc discharge between the anode assembly 200 and the cathode assembly 100. The cathode 110 of the cathode assembly 100 is positioned at an upper portion of the plasma generating space S. DC arc discharge occurs between the cathode 110 and the anode 210 by a high voltage applied to the cathode assembly 100.

At this time, the axis X1 of the anode assembly 200 may coincide with the axis of the cathode assembly 110.

A plasma generating gas introduction line 300 extending from an external plasma generating gas supply unit (not shown) to the plasma generating space S is provided at one end portion (i.e., an upstream end portion) of the anode assembly 200. The opening 230 is provided at the other end portion (i.e., the downstream end portion) of the anode assembly 200. The opening 230 may be referred to as a "torch outlet". The plasma flame is discharged through the opening 230.

The plasma generation gas introduction line 300 is configured to communicate with the plasma generation space S.

A plasma generating gas (for example, one selected from the group consisting of argon, nitrogen, helium, hydrogen, oxygen, steam, ammonia, and a mixture of some of these gases) is introduced into the plasma generating space S through the plasma generating gas introduction line 300. Then, the plasma generation gas is ionized by arc discharge generated in the plasma generation space S, thereby generating plasma.

The plasma generation gas introduction line 300 includes an inlet path 310, a distribution space 320, and a plurality of gas supply paths 330. The plasma generation gas introduced into the distribution space 320 through the inlet path 310 may be distributed in the distribution space 320 formed in the circumferential direction of the anode 210 and then supplied to the plasma generation space S through the gas supply path 330.

At this time, the gas supply path 330 is formed in parallel with or inclined with respect to the radial direction of the axis X1 of the anode assembly 200. Fig. 2 and 3 show that the gas supply path 330 is inclined at a predetermined angle (e.g., an acute angle (an angle less than 90 degrees)) with respect to the radial direction of the axis X1 of the anode assembly 200. With this arrangement, the plasma generating gas can be uniformly introduced into the plasma generating space S while generating a vortex or a rotational flow.

Fig. 2 and 3 are cross-sectional views taken along the line "ii (iii) -ii (iii)" of fig. 1 when viewed from the opening 230 of the anode assembly 200 toward the plasma generating gas introducing line 300 (i.e., when viewed from the bottom of the anode assembly 200).

In fig. 2, the plasma generation gas is introduced into the plasma generation space S through the inclined gas supply path 330 while rotating in the counterclockwise direction. In fig. 3, the plasma generation gas is introduced into the plasma generation space S through the gas supply path 330 inclined at an angle different from that shown in fig. 2 while rotating in the clockwise direction.

Further, the gas supply path 330 may be inclined with respect to the direction of the axis X1 of the anode assembly 200. In other words, the gas supply path 330 may be horizontally inclined at a predetermined angle as illustrated in fig. 2 and 3, or may be vertically inclined at a predetermined angle, or may be horizontally and vertically inclined at a predetermined angle.

When the outlet of the gas supply path 330 is formed at a position facing the cathode assembly 100 (specifically, the cathode 110), the plasma generation gas is introduced to rotate around the cathode assembly 100. Therefore, plasma can be uniformly generated in the plasma generation space S.

The anode assembly 200 may have a plasma-sustaining portion (not shown) extending from a lower end portion of the anode assembly 200. The plasma-holding portion maintains the plasma generated between the cathode 110 and the anode 210 in a stable state. When the anode assembly 200 has a plasma-sustaining portion, the plasma-generating space S extends to an inner space of the plasma-sustaining portion. By allowing the arc to occur at the inner space of the plasma-sustaining portion, the plasma can have an increased length in the axial direction and an increased diameter in the horizontal direction. The inner space of the plasma holding portion may have, for example, a shape in which the inner diameter gradually increases as the stepped portion is toward the lower portion of the plasma holding portion or a shape in which the inner diameter of the plasma generating space S is continuously increased toward the lower portion of the plasma holding portion, as long as the generated plasma can be maintained in a stable state and directed downward.

Next, the magnetic force generator 220 will be described in detail below.

The magnetic force generator 220 is disposed inside or outside the anode assembly 200. The magnetic force generator 220 generating a magnetic force may be a permanent magnet or an electromagnet.

Further, the magnetic force generator 220 may include a plurality of permanent magnets or electromagnets arranged radially with respect to the axis X1 of the anode assembly 200, or may include a single annular permanent magnet or electromagnet.

Fig. 4A is a cross-sectional view of the plasma generating apparatus taken along line "iva-iva" of fig. 1, showing that the magnetic force generator 220 includes a plurality of permanent magnets 220A embedded in the anode assembly 200 and arranged radially with respect to the axis X1 of the anode assembly 200. In fig. 4A, the magnetic force generator 220 includes six permanent magnets 220A. However, the number of permanent magnets 220A is not limited to six, but may be less than six or may be greater than six.

Fig. 4B is a cross-sectional view of another plasma generating apparatus taken along line "IVB-IVB" of fig. 1, which shows that the magnetic force generator 220 includes a single ring-shaped permanent magnet 220B embedded in the anode assembly 200. The axis of permanent magnet 220B may coincide with axis X1 of anode assembly 200.

Fig. 7 schematically illustrates a plasma generating apparatus according to another embodiment of the present disclosure, which shows that a plurality of permanent magnets 221, 222, and 223 arranged radially with respect to the axis X1 of the anode assembly 200 are provided at a plurality of levels inside the anode assembly 200.

Fig. 8 schematically illustrates a plasma generating apparatus according to yet another embodiment of the present disclosure, which shows that a plurality of permanent magnets 224 and 225 arranged radially with respect to the axis X1 of the anode assembly 200 are provided at a plurality of levels outside the anode assembly 200. The magnetic force generator 220 disposed outside the anode assembly 200 may be moved in a direction parallel to the axis X1 of the anode assembly 200 and in a direction perpendicular to the axis X1 of the anode assembly 200.

Embodiments of the present disclosure are intended to provide a plasma generating apparatus that can improve stability and durability by: by controlling the arrangement of the magnetic force generator 220, a force is applied to the anode arc point of the arc generated in the plasma generation space S. This will be described in detail with reference to fig. 5.

Fig. 5 illustrates a partial configuration of the cathode assembly 100 and the anode assembly 200 according to an embodiment of the present disclosure. When a high voltage is applied to the cathode 110 of the cathode assembly 100, an arc 500 occurs between the cathode 110 and the anode 210 in the plasma generation space S, and an anode arc point P, which is a part of the arc 500, is positioned on the anode 210.

At this time, when the plasma generating gas is introduced into the plasma generating space S through the plasma generating gas introducing line 300, the position of the anode arc point P is changed by the flow of the plasma generating gas. For example, if the plasma generating gas is introduced in a counterclockwise direction (see fig. 2) when viewed from the opening 230 of the anode assembly 200 toward the plasma generating gas introduction line 300 (i.e., when viewed from the bottom of the anode assembly 200), the anode arc point P is rotated in the counterclockwise direction by the plasma generating gas. In fig. 5, the direction of the vortex of the plasma generation gas is indicated by "g".

When the plasma generating apparatus is operated at a high voltage, the anode arc point P is positioned near the opening 230 of the anode assembly 200. The anode arc point P may be deviated from the end portion of the anode assembly 200 due to the eddy current of the plasma-generated gas. In that case, the plasma becomes extremely unstable. In order to maintain the plasma in a stable state, it is necessary to increase the current or operate the plasma generating apparatus at a low voltage. However, according to an embodiment of the present disclosure, it is intended to prevent the anode arc point P from deviating from the end portion of the anode assembly 200 without increasing the current or operating the plasma generating apparatus at a low voltage. To do so, the magnetic force generator 220 needs to be arranged such that a force is applied to the anode arc point P in a direction opposite to the rotation direction g of the plasma generation gas.

In fig. 5, the magnetic force generator 220 is arranged such that the polarities of the magnetic force generator 220 become opposite to each other in the direction of the axis X1 of the anode assembly 200. In fig. 5, the plasma generating gas is introduced in the counterclockwise direction as described above. At this time, the N-pole of the magnetic force generator 220 is directed toward the opening 230 of the anode assembly 200 (i.e., toward the lower portion of the anode assembly 200), and the S-pole of the magnetic force generator 220 is directed toward the cathode 110 (i.e., toward the upper portion of the anode assembly 200).

With this arrangement of the magnetic force generator 220, a magnetic field B is induced in the plasma generation space S, which is guided from the bottom to the top of the anode assembly 200. The current flows from the anode 210 towards the cathode 110, and near the location of the anode arc point P, the current I flows from the inner wall of the anode 210 towards the axis X1 of the anode assembly 200. In that case, according to Fleming's left hand rule, a force F is generated in a direction towards the ground at the position of the anode arc point P. In other words, when the rotation direction g of the plasma generating gas is in the counterclockwise direction, the N pole of the magnetic force generator 220 is directed toward the opening 230 of the anode assembly 200 so as to apply the force F to the anode arc point P in the clockwise direction. At this time, the force F in the clockwise direction may include a component directed from the bottom to the top of the anode assembly 200.

Therefore, even when the plasma generating apparatus is operated at a high voltage, the anode arc point P does not deviate from the end portion of the anode assembly 200, and further, plasma can be stably generated in the plasma generating space S. In addition, by moving the anode arc point P by means of the force generated by the magnetic field B induced by the magnetic force generator 220, it is possible to avoid abrasion and loss of the anode assembly 200 caused when the arc is concentrated at a specific portion of the anode assembly 200. As a result, the service life of the anode assembly 200 may be extended.

Fig. 6 illustrates a partial configuration of the cathode assembly 100 and the anode assembly 200 according to an embodiment of the present disclosure, which shows that the rotation direction g of the plasma generation gas is different from the rotation direction g illustrated in fig. 5. For example, if the plasma generating gas is introduced in a clockwise direction (see fig. 3) when viewed from the opening 230 of the anode assembly 200 toward the plasma generating gas introduction line 300 (i.e., when viewed from the bottom to the top of the anode assembly 200), the anode arc point P is rotated in a clockwise direction by the plasma generating gas.

At this time, the S pole of the magnetic force generator 220 is directed toward the opening 230 of the anode assembly 200 (i.e., toward the lower portion of the anode assembly 200), and the N pole of the magnetic force generator 220 is directed toward the cathode 110 (i.e., toward the upper portion of the anode assembly 200).

With this arrangement of the magnetic force generator 220, a magnetic field B is induced in the plasma generation space S, which is guided from the top to the bottom of the anode assembly 200. The current flows from the anode 210 towards the cathode 110, and near the location of the anode arc point P, the current I flows from the inner wall of the anode 210 towards the axis X1 of the anode assembly 200. In that case, according to the Fleming left-hand rule, a force F is generated in an upward direction from the ground at the location of the anode arc point P. In other words, when the rotation direction g of the plasma generating gas is in the clockwise direction, the S-pole of the magnetic force generator 220 may be directed toward the opening 230 of the anode assembly 200 so as to apply the force F to the anode arc point P in the counterclockwise direction. At this time, the force F in the counterclockwise direction may include a component directed from the bottom to the top of the anode assembly 200.

Therefore, even when the plasma generating apparatus is operated at a high voltage, the plasma can be stably generated and the lifespan of the anode assembly 200 can be extended.

In fig. 5 and 6, for example, an arrangement of polarities of a single magnetic force generator is illustrated. As in the case shown in fig. 5 and 6, the polarities of the plurality of permanent magnets 220A shown in fig. 4A, the polarities of the plurality of magnetic force generators 221 to 223 shown in fig. 7, and the polarities of the plurality of magnetic force generators 224 and 225 shown in fig. 8 may also be arranged so that a force is generated in a direction opposite to the rotation direction of the plasma generation gas. Similarly, the ring-shaped permanent magnet 220B shown in fig. 4B may be magnetized such that the polarities become opposite to each other in the direction of the axis X1 of the anode assembly 200 to thereby generate a force in a direction opposite to the rotation direction of the plasma generation gas.

In fig. 5 and 6, the magnetic force generator 220 is arranged such that a force is applied to the anode arc point P in a direction opposite to the rotation direction g of the plasma generation gas. However, the arrangement of the magnetic force generator 220 is not limited thereto. Depending on the purpose, the magnetic force generator 220 may be arranged such that a force is applied to the anode arc point P in the same direction as the rotation direction g of the plasma generation gas. For example, when the plasma generating gas is introduced in the counterclockwise direction as shown in fig. 5, the S pole of the magnetic force generator 220 may be directed toward the opening 230 of the anode assembly 200, and the N pole of the magnetic force generator 220 may be directed toward the cathode 110. In this case, a magnetic field directed from the top to the bottom of the anode assembly 200 is induced in the plasma generation space S, and a force in a counterclockwise direction is applied to the anode arc point P. When the plasma generating gas is introduced in the clockwise direction as shown in fig. 6, the N pole of the magnetic force generator 220 may be directed toward the opening 230 of the anode assembly 200, and the S pole of the magnetic force generator 220 may be directed toward the cathode 110. In that case, a magnetic field directed from the bottom to the top of the anode assembly 200 is induced in the plasma generation space S, and a force in a clockwise direction is applied to the anode arc point P.

In order to improve the service life of the anode assembly 200, various materials may be used for the guide member included in the anode assembly 200. This will be described in detail with reference to fig. 9.

Fig. 9 shows a configuration of an anode assembly 201 according to another embodiment of the present disclosure. The anode assembly 201 shown in fig. 9 may be used in the plasma generating apparatus of fig. 1 instead of the anode assembly 200. Redundant description of the same components in fig. 1 and 9 is omitted.

The anode assembly 201 includes: an anode 210 for generating plasma between the anode 210 and the cathode 110 by applying a high voltage to the cathode 110; a guide member 240 surrounding the anode 210; and a housing 250 surrounding the guide member 240. The anode 210, the guide member 240, and the case may have a cylindrical shape. The magnetic force generator 220 may be disposed inside the guide member 240.

The guide member 240 may be made of metal or plastic. Preferably, the guide member 240 is made of plastic. When the guide member 240 is made of plastic, the magnetic field induced by the magnetic force generator 220 may not be changed, and generation of parasitic current that may interfere with or affect the magnetic field may be prevented. Further, when the guide member 240 is made of plastic, heat is not transferred to the magnetic force generator 220, and thus, the magnetic properties of the magnetic force generator 220 are not affected.

The guide member 240 includes a first guide 241 disposed at an upper portion (i.e., the plasma generating gas introducing line 300 side in fig. 1) and a second guide 242 disposed at a lower portion (i.e., the opening 230 side in fig. 1). The second guide 242 is made of plastic having higher heat resistance than that of the first guide 241. The first guide member 241 may be made of plastic having low heat resistance, for example, at least one of PVC (polyvinyl chloride) and nylon. The second guide member may be made of plastic having high heat resistance, such as at least one of PTFE (polytetrafluoroethylene) and PEEK (polyetheretherketone). The anode assembly 201 has a relatively higher temperature near the opening 230 (i.e., near the torch exit) than other portions of the anode assembly 201. However, by using these materials for the guide member 240, deterioration or melting of the anode assembly 201 in the vicinity of the opening 230 can be prevented without high cost.

The magnetic force generator 220 may be disposed inside the guide member 240. At this time, the magnetic force generator 220 may be divided into a first magnetic force generator 226 disposed inside the first guide 241 and a second magnetic force generator 227 disposed inside the second guide 242. The first guide 241 and the second guide 242 may be coupled by a screw or an adhesive. On the other hand, the first and second guides 241 and 242 may be coupled by a magnetic force generated by polarities of the first and second magnetic force generators 226 and 227.

The housing 250 may be made of stainless steel. A coolant path 270 is formed between the housing 250 and the guide member 240 and between the guide member 240 and the anode 210. A coolant (e.g., cooling water) supplied from the coolant supplier 260 flows through the coolant path 270, thereby cooling the anode assembly 201.

More specifically, the coolant flows downward through the coolant path 270 formed between the housing 250 and the guide member 240, and then flows through the coolant path 270 formed below the bottom surface of the guide member 240, and then flows upward through the coolant path 270 formed between the guide member 240 and the anode 210.

At this time, the fins 280 may be disposed at the coolant path 270 formed under the bottom surface of the guide member 240. The fins 280 allow the coolant to circulate more efficiently. Thus, the relatively high temperature of the anode assembly 201 near the opening 230 (i.e., near the torch exit) can be effectively reduced.

The plasma generating apparatus described above may be an apparatus for processing a material selected from the group consisting of: perfluorinated compounds, chlorofluorocarbons, hydrofluorocarbons, hydrochlorofluorocarbons, dioxins, furans, volatile organic compounds, polychlorinated biphenyls and compounds thereof.

The configuration of a plasma generating apparatus having improved stability and durability has been described.

In the case of decomposing harmful gases by using a plasma generating apparatus, the harmful gases are treated at high temperatures, and this may generate nitrogen oxides. In particular, at high temperatures of about 800 ℃ or more, the amount of thermal NOx (nitrogen oxides) generated by reaction with the oxygen-containing reaction gas increases. Nitrogen oxides cause acid rain and photochemical smog, and are considered as one of the main air pollutants. Therefore, a technique capable of reducing nitrogen oxides is required.

Conventionally, catalytic devices or dilution devices are used to treat nitrogen oxides. However, these devices are not cost effective. As another solution, the use of oxygen-containing materials has been avoided to prevent the production of nitrogen oxides. However, in the case of decomposing harmful gases by using a material not containing oxygen, another toxic substance or other by-product is generated and deposited on the inner surface of the apparatus. Also, the harmful gas treatment efficiency is lowered.

In order to solve the above disadvantages, an embodiment of the present disclosure intends to provide a nitrogen oxide reduction apparatus capable of effectively reducing nitrogen oxides without lowering harmful gas treatment efficiency, and a gas treatment apparatus including the same.

Hereinafter, a gas treatment apparatus including a nitrogen oxide reduction apparatus capable of reducing nitrogen oxides will be described in detail.

Fig. 10 schematically illustrates a gas treatment apparatus according to an embodiment of the present disclosure. A plasma scrubber (scrubber) is illustrated as an example of a gas treatment device.

During semiconductor manufacturing, acid gases (such as BCl)₃、Cl₂、F₂HBr, HCl, HF, etc.) and PFC gases (such as CF)₄、CHF₃、C₂F₆、C₃F₈、C₄F₆、C₄F₈、C₅F₈、SF₆Etc.) are used to etch the surface of the wafer (wafer). In CVD (chemical vapour deposition) processes, use is made of a material such as AsH in the deposition step of the surface of the wafer₃、NH₃、PH₃、SiH₄、Si₂H₂Cl₂Etc., and using a gas such as NF in the cleaning step₃、C₂F₆、C₃F₈And so on PFC gases. Plasma scrubbers are used to treat these gases.

The plasma scrubber comprises a reaction chamber 30 and a nitrogen oxide reduction device (nitrogen oxide reduction chamber) 40. The plasma scrubber may further include a plasma torch 10, a pipe 50, a water tank 60, and a post-treatment unit 70.

The plasma torch 10 is a plasma generating apparatus for generating a plasma flame for thermally decomposing a gas introduced after an etching and CVD process at a high temperature. The plasma generating apparatus described with reference to fig. 1 to 9 may be used as the plasma torch 10.

The reaction chamber 30 is connected to the plasma torch 10, and provides a space in which the gas supplied through the gas supply line 20 is thermally decomposed by high-temperature plasma. When the temperature in the reaction chamber reaches about 800 ℃ or higher, thermal NOx is generated to a large extent. To suppress the generation of thermal NOx, a nitrogen oxide reducing device 40 is connected to the rear end of the reaction chamber 30. The nox reducing device 40 will be described in detail later.

A pipe 50 is connected to the rear end of the nitrogen oxide reducing apparatus 40. The duct 50 has a water injection nozzle 51 formed at a sidewall thereof. The water injection nozzles 51 spray water in a fine mist state, thereby rapidly cooling the gas treated in the reaction chamber 30.

The post-treatment unit 70 uses water injection nozzles to treat water-soluble or acid gases and particulate materials generated after decomposition. The water tank 60 is configured to store and draw in water and particulate material introduced from the conduit 50 and the aftertreatment unit 70.

Hereinafter, the nitrogen oxide reduction apparatus 40 will be described in detail with reference to fig. 11. The nitrogen oxide reducing apparatus 40 includes a cylindrical housing (pipe) 47. An opening at one end of the housing 47 is connected to the rear end of the reaction chamber 30. An opening at the other end of the housing 47 is connected to the front end of the duct 50. The gas treated by the plasma in the reaction chamber 30 flows through the reaction chamber 30, the nitrogen oxide reduction device 40, and the line 50 in this order. The nitrogen oxide reducing apparatus 40 includes a cooling unit for rapidly cooling the gas treated in the reaction chamber 30 to a temperature lower than the nitrogen oxide generating temperature.

Fig. 11 shows a plurality of gas injection nozzles 44 as an example of the cooling unit. The gas injection nozzle 44 may be arranged radially with respect to the axis of the housing 47. The gas injection nozzle 44 may be formed at the housing 47, or may be formed at the gas supply ring 45, which is a separate member in the housing 47. The gas supply ring 45 may be formed in an annular shape and positioned inside a housing 47 of the nitrogen oxide reduction apparatus 40.

FIG. 12 shows an annular gas supply ring 45 with a plurality of gas injection nozzles 44. The gas injection nozzles 44 may be spaced apart from each other at regular intervals on the gas supply ring 45.

The low-temperature gas is injected into the inner space of the nitrogen oxide reducing apparatus 40 through the gas injection nozzle 44. At this time, a gas having no reactivity or low reactivity is used as the low-temperature gas. For example, an inert gas containing at least one of nitrogen and argon may be used as the low-temperature gas.

The temperature of the low temperature gas is low enough to rapidly cool the gas processed in the reaction chamber 30 to a temperature below the nitrogen oxide generation temperature. For example, the cryogenic gas has a temperature of about 300 ℃ or less.

When the high-temperature gas processed in the reaction chamber 30 reaches the nitrogen oxide reduction apparatus 40, the low-temperature gas injected from the gas injection nozzle 44 rapidly cools the high-temperature gas. Thus, the generation of nitrogen oxides is reduced.

The gas injection nozzle 44 may be formed at any position in the axial direction of the housing 47 of the nitrogen oxide reducing apparatus 40. The gas injection nozzle 44 may be formed at a plurality of levels having different heights. When the gas injection nozzle 44 is close to the reaction chamber 30, the efficiency of harmful gas treatment may be lowered, and when the gas injection nozzle 44 is far from the reaction chamber 30, the nitrogen oxide reduction effect is lowered. Therefore, the gas injection nozzle 44 needs to be disposed at a position where a desired harmful gas treatment efficiency and a desired nitrogen oxide reduction effect can be achieved.

For example, the temperature of the nitrogen oxide reducing device 40 becomes lower toward a position away from the reaction chamber 30. In the case where the gas injection nozzle 44 is provided at a position where the temperature of the nitrogen oxide reducing apparatus 40 reaches about 800 ℃, the generation of nitrogen oxides can be effectively suppressed without lowering the efficiency of harmful gas treatment.

In addition, a cooling water path 43 may be formed between the outer wall and the inner wall of the nitrogen oxide reduction device 40. Cooling water is introduced from a cooling water inlet line 41 connected to the lower end of the nitrogen oxide reducing apparatus 40. Then, the cooling water flows from the bottom to the top of the cooling water path 43 and is discharged from the cooling water outlet line 42 connected to the upper end of the nitrogen oxide reduction device 40. Therefore, the nitrogen oxide reducing device 40 is cooled by the cooling water, and the generation of nitrogen oxide is more effectively reduced.

Fig. 13 illustrates a nitrogen oxide reduction apparatus 40 according to another embodiment of the present disclosure. Redundant description of the same components in fig. 1 and 13 is omitted.

The nitrogen oxide reduction apparatus 40 shown in fig. 13 includes a heat exchanger 46 as a cooling unit. The heat exchanger 46 may include a plurality of heat exchange pipes through which liquefied hydrogen or BOG (boil off gas) flows. On the other hand, the heat exchanger 46 may include plates, tubes, and the like that exchange heat. When the high-temperature gas processed in the reaction chamber 30 reaches the nitrogen oxide reducing apparatus 40, the heat exchanger 46 rapidly cools the high-temperature gas. Thus, the generation of nitrogen oxides is reduced.

The cooling unit installed at the nitrogen oxide reduction apparatus 40 is not limited to the gas injection nozzle 44 or the heat exchanger 46. Any other units may be used as the cooling unit as long as they can rapidly cool the gas from the reaction chamber 30. As for the cooling unit, both the gas injection nozzle 44 and the heat exchanger 46 may be used.

Embodiments of the present disclosure can effectively reduce nitrogen oxides by cooling a plasma-treated gas using a cooling unit without reducing harmful gas treatment efficiency.

Embodiments of the present disclosure have been described based on the embodiments illustrated in the drawings. However, the above description is merely an example, and those skilled in the art will appreciate that various changes and modifications may be made. Therefore, the technical scope of the present disclosure should be determined by the technical idea of the appended claims.