KR101041026B1 - Hollow type plasma torch, Combusition apparatus plasma/gas bunner and method of melting using the appratus - Google Patents

Abstract

Provided are a cavity plasma torch, a plasma / gas mixed combustion device, and a melting method using the same. In the plasma / gas mixed combustion device, when a power is applied to a coil wound around the electrode body, a magnetic field is formed in the reaction space inside the electrode body, and the plasma generated during the discharging process is affected by the magnetic field so that the flow flows in one direction. And a combustion nozzle which extends to the outlet side of the hollow plasma torch implementing the apparatus to maintain the swirl and which mixes air and fuel gas to generate a flame having a temperature suitable for processing an object. In the melting method, a plasma generation step of converting the reaction gas introduced into the reaction space inside the electrode body into plasma, applying power to a coil wound around the outer edge of the electrode body, and a magnetic field in the reaction space inside the electrode body. Plasma swirl flow is formed so that the plasma has a constant swirl pattern flow in the reaction space. Swirl flow forming step, flame generation step of generating a high-temperature flame through the combustion reaction by mixing air and fuel gas to the rotating plasma, using the high-temperature flame generated through the flame generation step to melt the object received in the melting furnace And a secondary combustion step of supplying and re-burning the primary combustion step of burning or melting and the exhaust gas generated in the primary combustion step and exhausted outside the melting furnace to a secondary combustion chamber provided separately from the melting furnace. Shall be.

Plasma torch, cavity electrode, coil, magnetic field, combustion nozzle

Description

Hollow type plasma torch, Combusition apparatus plasma / gas bunner and method of melting using the appratus}

The present invention relates to a cavity-type plasma torch, a plasma / gas mixed combustion device, and a melting method using the same. The present invention relates to a cavity-type plasma torch capable of forming a flame, a plasma / gas mixed combustion device, and a melting method using the same.

Torch that applies a high heat to a specific part for the purpose of welding, cutting, surface treatment, waste combustion, etc. is provided in various structures depending on the type of fuel (liquid fuel, gaseous fuel) to be burned. In addition, in recent years, a higher combustion heat can be obtained by introducing a working gas (nitrogen, oxygen, hydrogen, argon, helium, methane, propane, etc.) into a space where a high pressure current is applied between two electrodes. Plasma torch is widely adopted.

Plasma torch is a clean technology that can be adjusted to have a suitable temperature condition according to the working environment, and does not generate any harmful substances during operation because it mainly uses electric power and inert gas. It has the advantage of being able to achieve unacceptable high temperatures (2,000 K to 10,000 K), but because of the need to use electricity as a raw material and to continuously supply inert gas, it is necessary to operate the device for small quantity production. There is a disadvantage in that a considerable expense is required.

Therefore, in recent commercial applications, the torch operation is mainly output to hundreds of kW or more to overcome the economic problems by melt-processing a large amount of material in a short time, and the thermal plasma torch is improved to improve the stability of the plasma jet during the operation process. Although research is being actively conducted to secure the reliability of the torch, when the torch is operated at a high output, the electrode corrosion is inevitably accelerated due to the high torch operating current, resulting in a problem of shortening the electrode life.

Therefore, in order to successfully secure plasma-based material melting technology and activate related technologies, it is urgent to develop a thermal plasma torch capable of generating stable thermal plasma jets for a long time without abnormal discharge and having low electrode corrosion even in high power operation. to be.

The technical problem to be solved by the present invention is to minimize the corrosion of the electrode due to the generation of high temperature arc even in high-power operation environment, and to adjust the amount of air and additional fuel gas to the plasma generated through the torch, the temperature suitable for the object treatment The present invention provides a cavity plasma torch and a plasma / gas mixed combustion apparatus capable of variously creating an environment.

Another technical problem to be solved by the present invention is to perform a melting on the object to be melted by using the plasma / gas mixed combustion apparatus, the plasma / gas mixed combustion apparatus to implement the melting on the object more efficiently It is to provide a melting method used.

As a means for solving the above technical problem, the present invention, a hollow hollow cathode electrode body having a closed end and an open end on one side and the other side, the coil is wound around the inner space to form a magnetic field; A hollow anode electrode having an inlet and an outlet, the inlet being coaxially disposed with the cathode electrode body so as to face the open end of the cathode electrode body at a predetermined distance, and having a coil wound around its inner space to form a magnetic field; sieve; A gas supply port forming a flow path through which a reaction gas for plasma generation can be introduced into a reaction space inside the cathode electrode body and the anode electrode body through a gap between the cathode electrode body and the anode electrode body; And a hollow outer housing having a diameter and a length sufficient to accommodate the cathode electrode body, the anode electrode body, and the gas supply port, and accommodating the cathode electrode body, the anode electrode body, and the gas supply port therein. It provides a cavity plasma torch configured to include.

Here, the cathode electrode body and the anode electrode body includes an outer insulator having a pair of coolant ports through which coolant is introduced and exited, and a hollow electrode inserted into the outer insulator, wherein the outer insulator and the electrode are spaced apart from each other. By forming a coolant passage through which the coolant may flow, it is desirable to prevent breakage or shortening of life due to overheating of the device during the high temperature plasma generation process.

In the present embodiment, it is preferable that the hollow electrode adopts a copper-based special alloy having high corrosion resistance even in an ultra high temperature region during arc generation in a plasma generation process.

As another means for solving the above technical problem, the present invention, a hollow plasma torch having the above configuration; And a combustion nozzle into which a high temperature plasma generated from the plasma torch is introduced, and a combustion reaction is performed by mixing air and fuel gas into the introduced high temperature plasma to provide a combustion reaction.

Here, the combustion nozzle, the inlet for introducing the plasma, the outlet for discharging the high temperature flame by combustion to the outside, and the mixing space and mixing is formed between the inlet and the outlet having an expanded cross-sectional diameter compared to the inlet and outlet And a plurality of air injection ports and fuel gas injection ports communicating with the mixing space through the combustion nozzle wall for forming the mixing space for mixing air and fuel gas in the plasma introduced into the space. .

In connecting and mounting the combustion nozzle to the plasma torch, the combustion nozzle is connected to one side of the outer housing of the hollow plasma torch by using a flange connection so that the inlet of the combustion nozzle communicates with the anode electrode outlet of the hollow plasma torch. Linking is preferred.

Preferably, when the plurality of air injection ports and fuel gas injection ports have an inclined slope toward the outlet of the combustion nozzle, when air and fuel gas are introduced toward the combustion nozzle outlet through the injection port, The venturi phenomenon caused by the air and fuel gas flows may be used to smoothly introduce plasma into the combustion nozzle mixing space.

More preferably, the plurality of air injection ports are formed to be deflected by a predetermined distance in either a clockwise or counterclockwise direction with respect to the horizontal axis and the longitudinal axis extending from the center of the mixing space of the combustion nozzle, and are introduced by air introduced into the mixing space. Preferably, swirl flow can be formed in the mixing space.

As another method for solving the above technical problem, the present invention, by introducing a reaction gas between the cathode electrode body and the anode electrode body through a gas supply port, by applying power to the cathode electrode body and the anode electrode body to the electrode A plasma generation step of plasmalizing the reaction gas introduced into the reaction spaces inside the sieves; Applying power to the coil wound around the outer edge of the cathode electrode body and the anode electrode body to form a magnetic field in the reaction space inside the electrode body, by the magnetic field plasma turning so that the plasma has a constant swirl pattern flow in the reaction space A swirl flow forming step of forming a flow; A flame generating step of generating a high temperature flame through a combustion reaction by mixing air and fuel gas in a turning plasma; And a primary combustion step of burning or melting a melting object accommodated in a melting furnace by using a high temperature flame generated through the flame generation step. do.

The method may further include an electrode body cooling step of cooling the cathode electrode body and the anode electrode body by introducing and drawing cooling water into the cathode electrode body and the anode electrode body during the plasma generation process.

In the primary combustion step, the discharge direction of the flame has an inclination toward the bottom of the melting furnace and at the same time, so that the high temperature combustion gas by the flame can flow while forming a constant turning pattern from one side of the melting furnace to the other side It may be good to have a slope to the other side.

Further, the secondary combustion step of supplying the exhaust gas generated in the primary combustion step and exhausted to the outside of the melting furnace to the secondary combustion chamber provided separately from the melting furnace and reburned; may further include a.

At this time, the waste heat recovery step to recover the waste heat containing the exhaust gas discharged from the secondary combustion chamber to preheat the air introduced into the secondary combustion chamber; preferably further comprises a.

According to the present invention having the above-described configuration, when power is applied to the coil wound around the electrode body, a magnetic field is formed in the reaction space inside the electrode body, and the plasma generated during the discharging process is rotated toward one direction under the influence of the magnetic field. Maintain a Swirl. Therefore, the hot arc point does not belong to any one point of the electrode body during the discharge process for plasma generation, and rotates at a high speed inside the electrode body under the influence of the plasma swirl flow. Accordingly, even in a high output operating environment, corrosion of the electrode due to high temperature arc generation can be minimized, and consequently, an effect of reducing the overall maintenance of the device due to the extension of the electrode life can be expected.

In addition, the present invention, through the simple operation of adjusting the mixing amount of the air and the additional fuel gas provided from the outside of the combustion nozzle to the plasma generated through the torch, variously adjust the output temperature of the discharge flame to have a temperature range suitable for the object treatment Since it is possible to do so, there is an advantage that can be widely applied in the field where ultra-high temperature work is required.

In addition, in the melting method according to the present invention, in performing the melting of the object to be melted using the plasma / gas mixed combustion apparatus, waste heat is recovered and utilized for combustion, thereby saving energy by more efficient operation of energy. The advantage is that it can be implemented.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a plasma / gas mixed combustion device according to a preferred embodiment of the present invention, FIG. 2 is a schematic configuration diagram schematically showing the configuration of the plasma torch shown in FIG. 1, and FIG. 3 is shown in FIG. 1. Front view of the combustion nozzle as viewed from the combustion nozzle inlet side.

1 to 3, the plasma / gas mixed combustion apparatus includes a hollow plasma torch 10 and a cavity plasma torch 10 exiting at a high temperature to generate a high temperature arc through a plasma reaction through electrode discharge. And a combustion nozzle 15 to be mounted. The cavity-type plasma torch 10 has a cavity-type structure in which a reaction space is formed therein, and a high-temperature plasma generated through the plasma torch 10 is introduced into the combustion nozzle 15. Air and fuel gas are mixed in the plasma to output a flame having a temperature range suitable for object treatment to the outside.

Referring to FIG. 2, the cavity-type plasma torch 10 includes two electrodes for discharging reaction, that is, a cathode electrode body 100 and an anode electrode body 110. The cathode electrode body 100 is a hollow body having a closed end and an open end (not shown) on one side and the other side, respectively, and the coil 102 for forming a magnetic field is wound around its inner space, and the anode electrode body ( 110 is also a hollow body, having an inlet (I) and an outlet (E), the coil 112 for forming a magnetic field is wound around the inner space.

The anode electrode body 110 is disposed coaxially with the cathode electrode body 100 such that the inlet I of the anode electrode body 110 faces the open end of the cathode electrode body 100 at a predetermined distance. And the cathode electrode body 100 and the anode electrode body through the gas supply port 120 including a gap 125 between the open end of the cathode electrode body 100 and the inlet I of the anode electrode body 110. 110) Reaction gas for plasma generation is introduced into the internal reaction spaces 107 and 117.

As described above, in the present invention, the pair of electrode bodies 100 and 110 are formed in a hollow shape, and coils 102 and 112 are wound around the outer edge thereof, so that a gap between the two electrode bodies 100 and 110 is separated. The reaction gas is introduced into the reaction spaces 107 and 117 inside the electrode body 125, and the coils 102 and 112 wound around the pair of electrode bodies 100 and 110 and the outer edge thereof. When a high frequency high voltage is applied, the arc discharge, that is, the arc point is not fixed at any position in the plasma generation process and continuously moves while forming a swirl flow pattern in the electrode body reaction space. Therefore, the corrosion of the electrode is significantly reduced, unlike the conventional case where the arc point is attributed to a specific point.

The coils 102 and 112 wound around the outer edges of the two electrode bodies 100 and 110 are applied to the arc by applying a magnetic field to the plasma and the arc formed inside the two electrode bodies 100 and 110 on the hollow body. Plasma particles in the interior are subjected to the force of Lorentz (Lorentz) to move in a direction perpendicular to the magnetic field forming direction. Therefore, when the current is applied to the coil in alternating current, a magnetic field is generated by swapping the N pole and the S pole, causing the arc to oscillate from side to side, and controlling the magnitude and switching frequency of the current applied to the coil. In this case, since the size and magnetism of the magnetic field generated in the coil can be freely controlled, the weaving width and the weaving frequency can be easily adjusted.

The cathode electrode body 100 and the anode electrode body 110 can only be heated to a high temperature by generating a plasma under a high voltage, and when the electrode body is heated above the aptitude level, it can only affect the plasma generating performance. Therefore, even in the process of generating plasma, the two electrode bodies require continuous cooling to maintain a constant plasma generation performance. For this purpose, coolant is introduced from the outside into the two electrode bodies 100 and 110 applied to the present invention. Cooling water passages 108 and 118 are formed to form a movement path so as to escape to the outside via the

In order to form the cooling water passages 108 and 118, the cathode electrode body 100 and the anode electrode body 110 have hollow electrodes 106 and 116 inside the hollow outer insulator 104 and 114. It has a configuration inserted at a predetermined interval, so that the space between the outer insulator 104, 114 and the electrode 106, 116 corresponds to the coolant passage (108) 118 through which the coolant can flow do. At this time, a pair of coolant ports 109 for introducing coolant into the coolant passages 108 and 118 into the outer insulators 104 and 114 and letting coolant through the coolant passages 108 and 118 to the outside. 119 is provided.

Herein, in the case of the electrodes 106 and 116, the electrode diameter and length ratio may vary from time to time depending on the gas used and the operating conditions. Therefore, the electrode length may be easily adjusted by simply replacing the electrode according to the situation. Do.

The cathode electrode body 100, the anode electrode body 110 and the gas supply port 120 are simultaneously accommodated in a hollow outer housing 130 having a diameter and length sufficient to accommodate them, thereby implementing the present invention. The plasma torch 10 according to the example has a cylindrical shape that is long in the longitudinal direction as a whole, and the combustion nozzle 15 at one outlet side of the plasma torch 10 allows separation / assembly to each other through a flange connection. Connected.

As shown in FIG. 1, the combustion nozzle 15 applied to the present invention includes an inlet 150 for introducing plasma, an outlet 154 for discharging high-temperature flames by combustion, and an inlet 150. For mixing air and fuel gas in the mixing space 152 and the plasma introduced into the mixing space 152 formed between the outlet 154 and having an expanded cross-sectional diameter compared to the inlet 150 and the outlet 154, And a plurality of air injection ports 156 and fuel gas injection ports 158 communicating with the mixing space 152 through the combustion nozzle 15 wall surface for forming the mixing space 152.

In this case, the plurality of air injection ports 156 and fuel gas injection ports 158 have an inclination inclination toward the outlet 154 of the combustion nozzle 15, through the injection ports 156 and 158. When air and fuel gas are introduced toward the combustion nozzle 15 exit 154, plasma may be smoothly introduced into the combustion nozzle mixing space 152 by the venturi phenomenon caused by the air and fuel gas flow. As shown in FIG. 3, the plurality of air injection ports 156 are positioned at a predetermined distance in a clockwise or counterclockwise direction with respect to the horizontal axis and the vertical axis extending from the center of the mixing space 152 of the combustion nozzle 15. Thus, when air is introduced into the mixing space 152 through the air injection port 156, a swirl flow is formed inside the mixing space 152, whereby a high temperature generated in the combustion nozzle 15 is generated. Flame, that is, flame also goes straight to discharge direction It has a radially turning movement while maintaining the castle.

Since the combustion nozzle 15 as described above provides a physical interface directly to the flame at high temperature, it is preferable that the combustion nozzle 15 is made of a material having excellent heat resistance, and the discharge of the flame is such that the flame naturally converges while passing through the combustion nozzle. The exit inner diameter is preferably formed to have a narrow shape compared to the mixing space 152 and to form a smooth smooth curved surface to minimize the friction that inhibits the flow and discharge of the flame.

Next, a melting method that can be performed by employing the plasma / gas mixed combustion apparatus described above will be described with reference to the accompanying drawings.

Figure 4 is a flow chart schematically showing a melting method that can be performed by employing the plasma / gas mixed combustion apparatus according to an embodiment of the present invention, Figure 5 schematically shows a system for implementing the melting method according to FIG. It is a schematic block diagram shown.

4 to 5, the melting method that can be performed by employing the plasma / gas mixed combustion device is largely divided into a plasma generation step, a plasma swirl flow formation step, a flame generation step, a first combustion step, and a second combustion step. As a specific means for implementing such a melting method, the plasma / gas mixed combustion device 1, the combustion device 1 is equipped with a melting furnace (2) for primary combustion and melting the object to be melted And a secondary combustion chamber 3 for reburning the exhaust gas generated in the primary combustion process.

The plasma generation step is to plasma the reaction gas introduced into the reaction space inside the electrode bodies, introducing a reaction gas between the cathode electrode body and the anode electrode through a gas supply port and then the cathode electrode body and the anode electrode Plasma the reaction gas introduced into the reaction space inside the electrode bodies by applying power to the sieve. In the swirl flow forming step, power is applied to a coil wound around the outer edge of the cathode electrode body and the anode electrode body. By forming a magnetic field in the reaction space inside the electrode body by the magnetic field to form a plasma swirl flow so that the plasma has a constant flow pattern in the reaction space.

At this time, in the plasma generation process, coolant is introduced into and drawn from the cathode electrode body and the anode electrode body to continuously cool the cathode electrode body and the anode electrode body exposed to a high temperature environment to generate a plasma of even quality. The method may further include an electrode body cooling step of cooling the two electrode bodies.

The flame generation step is a process of generating a high-temperature flame through the combustion reaction by mixing air and fuel gas in the plasma in turn, in this process by controlling the mixing amount of the air and additional fuel gas mixed in the plasma, the object treatment The output temperature of the flame can be simply and varied to have a temperature range that is suitable for the

The primary combustion step is a process of burning or melting a melting object contained in the melting furnace 2 shown in FIG. 5 using the high temperature flame generated through the flame generating step, which is introduced into the melting furnace in this process. In order to prevent the discharge of the particles to be melted in some non-melt state by increasing the residence time of the high temperature combustion gas to the maximum, for this purpose, the high temperature combustion gas by the flame is constant from one side to the other side of the melting furnace 2. It is desirable to be able to flow while forming a swing pattern.

Specifically, the discharge direction of the flame in the primary combustion step has a slope toward the bottom of the melting furnace 2, and at the same time, to have a slope toward the other side on one side of the melting furnace 2, thereby the melting furnace 2 It is preferable to have the hot combustion gas by the flame introduced into the flow to form a constant swing pattern from one side of the melting furnace to the other side. As a specific means for realizing this, as shown in Figs. 6 to 7 showing the melting furnace 2, it defines the position where the combustion device 1 is mounted, and the high temperature flame discharged from the combustion device 1 The flame inlet 20 to be introduced into the receiving space is installed on one side of the melting furnace, the flame inlet 20 has a slope toward the bottom of the melting furnace 2, while at the same time inclined toward the other side of the melting furnace (2) It can be implemented by having

The secondary combustion step is a process of supplying and re-burning the exhaust gas generated in the primary combustion step and exhausted to the outside of the melting furnace 2 to the secondary combustion chamber 3 provided separately from the melting furnace. By re-burning the pollutants contained in the exhaust gas in the step, it is a process for preventing the environmental pollution due to the air emission of the exhaust gas containing pollutants in advance.

The exhaust gas exhausted from the secondary combustion chamber 3 through the secondary combustion step contains thermal energy that can be recycled. Thus, the waste heat containing exhaust gas exhausted from the secondary combustion chamber 3 is recovered. The method further includes a waste heat recovery step of preheating the air introduced into the secondary combustion chamber. The waste heat generated during the combustion process is used to preheat the air for combustion, and thus the energy consumed for cooling and exhausting the exhaust gas is finally required. The energy consumed in heating the air can be reduced.

According to the embodiment of the present invention as described above, when the power is applied to the coil wound around the electrode body, a magnetic field is formed in the reaction space inside the electrode body, the plasma generated during the discharge process is affected by the magnetic field in any one direction Maintain a swirl towards you. Therefore, the hot arc point does not belong to any one point of the electrode body during the discharge process for plasma generation, and rotates at a high speed inside the electrode body under the influence of the plasma swirl flow. Accordingly, even in a high output operating environment, corrosion of the electrode due to high temperature arc generation can be minimized, and consequently, an effect of reducing the overall maintenance of the device due to the extension of the electrode life can be expected.

In addition, the present invention, through the simple operation of adjusting the mixing amount of the air and the additional fuel gas provided from the outside of the combustion nozzle to the plasma generated through the torch, variously adjust the output temperature of the discharge flame to have a temperature range suitable for the object treatment Since it is possible to do so, there is an advantage that can be widely applied in the field where ultra-high temperature work is required.

In addition, in the melting method according to the present invention, in performing the melting of the object to be melted using the plasma / gas mixed combustion apparatus, waste heat is recovered and utilized for combustion, thereby saving energy by more efficient operation of energy. The advantage is that it can be implemented.

In the above described and described with respect to a specific embodiment with respect to the present invention, the present invention will be variously modified and changed without departing from the spirit or scope of the present invention provided by the claims below. It will be appreciated that one of ordinary skill in the art can readily understand that the present invention can be used.

1 is a cross-sectional view of a plasma / gas mixed combustion device according to a preferred embodiment of the present invention.

2 is a schematic configuration diagram schematically showing the main configuration of the plasma torch shown in FIG.

3 is a front view of the combustion nozzle shown in FIG. 1 as viewed from the combustion nozzle inlet side; FIG.

Figure 4 is a flow chart schematically showing a melting method that can be performed by employing a plasma / gas mixed combustion apparatus according to an embodiment of the present invention.

5 is a schematic configuration diagram schematically showing the overall configuration of a system for implementing the melting method according to FIG.

6 and 7 are side and plan views, respectively, of the melting furnace shown in FIG. 5.

Description of the Related Art [0002]

1.Plasma / Gas Mixture Combustor

3 ... 2nd combustion chamber 10 ... plasma torch

15 Combustion nozzle 100 Cathode electrode body

110 ... anode electrode body 102, 112 ... coil

104, 114 ... external insulator 106, 116 ... electrode

107, 117 ... Reaction space 108, 118 ... Coolant passage

109, 119 ... Cooling water port 150 ... Combustion nozzle inlet

152 Mixing space 154 Combustion nozzle exit

156.Air injection port 158 ... Fuel gas injection port

Claims (12)

A hollow hollow cathode electrode body having a closed end and an open end on one side and the other side, and a coil wound around the inner space to form a magnetic field; A hollow anode electrode having an inlet and an outlet, the inlet being coaxially disposed with the cathode electrode body so as to face the open end of the cathode electrode body at a predetermined distance, and having a coil wound around its inner space to form a magnetic field; sieve; A gas supply port forming a flow path through which a reaction gas for generating plasma is introduced into the reaction space inside the cathode electrode body and the anode electrode body through a gap between the cathode electrode body and the anode electrode body; And A hollow outer housing having a diameter and a length sufficient to accommodate the cathode electrode body, the anode electrode body, and the gas supply port, and accommodating the cathode electrode body, the anode electrode body, and the gas supply port therein; Cavity plasma torch constructed. The method of claim 1, The cathode electrode body and the anode electrode body, An external insulator with a pair of coolant ports into which coolant is introduced and exited, It includes a hollow electrode inserted into the outer insulator, And a coolant passage through which the coolant flows, spaced apart from the outer insulator and the electrode. delete The cavity type plasma torch according to any one of claims 1 to 2; And And a combustion nozzle into which a high temperature plasma generated by the plasma torch is introduced, and a combustion reaction is performed by mixing air and fuel gas into the introduced high temperature plasma. The method of claim 4, wherein The combustion nozzle, An inlet for plasma introduction; An outlet for discharging the high temperature flame by combustion to the outside; A mixing space formed between the inlet and the outlet and having an enlarged cross-sectional diameter compared to the inlet and the outlet; And And a plurality of air injection ports and fuel gas injection ports communicating with the mixing space through the combustion nozzle wall for forming the mixing space for mixing air and fuel gas in the plasma introduced into the mixing space. Plasma / gas mixed combustion apparatus. The method of claim 5, The combustion nozzle, And the inlet is connected to one side of an outer housing of the hollow plasma torch such that the inlet communicates with an anode electrode outlet of the hollow plasma torch. The method of claim 5, The plurality of air injection port and fuel gas injection port, And a slope inclined toward the outlet of the combustion nozzle. The method of claim 7, wherein The plurality of air injection port, Plasma / gas mixed combustion device characterized in that formed to be deflected a predetermined distance in either the clockwise or counterclockwise direction with respect to the horizontal axis and the longitudinal axis extending from the center of the mixing space of the combustion nozzle. Reaction gas is introduced between the cathode electrode body and the anode electrode body through a gas supply port, and power is applied to the cathode electrode body and the anode electrode body to introduce reaction gas introduced into the reaction space inside the cathode electrode body and the anode electrode body. Plasma generating step to plasma; Applying a power to the coil wound around the outer edge of the cathode electrode body and the anode electrode body to form a magnetic field in the reaction space inside the cathode electrode body and the anode electrode body, the magnetic field of the plasma is a constant turning pattern in the reaction space A swirl flow forming step of forming a plasma swirl flow to have a flow; A flame generating step of generating a high temperature flame through a combustion reaction by mixing air and fuel gas in a turning plasma; A primary combustion step of burning or melting a molten object accommodated in a melting furnace by using a high temperature flame generated through the flame generating step; And And a second combustion step of supplying the exhaust gas generated in the first combustion step and exhausted to the outside of the melting furnace to a secondary combustion chamber provided separately from the melting furnace to reburn the plasma / gas mixed combustion. Melting method using a device. The method of claim 9, And an electrode body cooling step of cooling the cathode electrode body and the anode electrode body by introducing and extracting cooling water into the cathode electrode body and the anode electrode body in the plasma generation step. Melting method using. The method of claim 9, In the first combustion step, The discharge direction of the flame has an inclination toward the bottom of the furnace and at an inclination from one side of the furnace to the other so that the hot combustion gas by the flame can flow while forming a constant turning pattern from one side of the melting furnace to the other side. Melting method using a plasma / gas mixed combustion device characterized in that. The method of claim 9, And a waste heat recovery step of recovering waste heat contained in the exhaust gas exhausted from the secondary combustion chamber to preheat the air introduced into the secondary combustion chamber.

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