TWM632701U - Spot type atmospheric pressure plasma device - Google Patents

Abstract

A spot type atmospheric pressure plasma device includes a metal casing, a metal electrode, a dielectric layer, and a gas channel. The metal casing has an inner space. The metal electrode is disposed in the inner space. The dielectric layer is disposed in the inner space and surrounds an outer side surface of the metal electrode. A central area of a bottom of the dielectric layer has a plasma jet, and a bottom of the metal electrode is adjacent to the plasma jet. The gas channel includes a first section, a second section, and a third section. The first section passes through the metal casing and the dielectric layer. The second section is connected to the first section and extends between the dielectric layer and the outer side surface of the metal electrode. The third section is connected to the second section, and is configured to direct a working gas to the plasma jet.

Description

point type atmospheric plasma device

The present disclosure relates to a plasma technology, and in particular to a point-type atmospheric plasma device.

Atmospheric plasma is plasma produced at or near atmospheric pressure. Since the atmospheric plasma system has no vacuum equipment, the workpiece can be processed continuously. Therefore, compared with the vacuum plasma system, the atmospheric plasma system has advantages in terms of equipment and process costs.

According to the different forms of plasma, atmospheric plasma can be roughly divided into corona discharge, dielectric barrier discharge (DBD), plasma jet (Plasma jet), and plasma torch (Plasma torch), etc. . The dielectric discharge technology has attracted attention because the discharge gas temperature is close to room temperature, which can avoid wasting energy in raising the gas temperature. However, the plasma density generated by the dielectric discharge technology is low, and the plasma removal efficiency is not high.

Therefore, an object of the present disclosure is to provide a point-type atmospheric plasma device, the gas channel of which can directly guide the working gas to the plasma injection port in the central area of the bottom of the dielectric layer. In this way, most of the working gas can be dissociated near the plasma injection port to form plasma. Therefore, the formation of plasma in the inner space of the metal shell can be greatly reduced, which can not only avoid unnecessary waste of power, but also make the plasma more concentrated and closer to the workpiece to be treated, thereby improving the plasma treatment effect.

Another object of the present disclosure is to provide a point-type atmospheric plasma device, the outlet section of the gas flow channel can be pierced in the metal electrode, so that the formation of plasma at the outlet section of the gas flow channel can be avoided, and further Reduce unnecessary waste of power and make plasma more concentrated. Therefore, plasma treatment can be more focused, avoiding damage to non-treated areas.

Another object of the present disclosure is to provide a point-type atmospheric plasma device, which can use a sealing ring to surround the outer side of the dielectric layer to seal the cavity of the metal casing, so that the plasma can be more effectively avoided. formed in the chamber.

Another object of the present disclosure is to provide a point-type atmospheric plasma device, the outlet section of the gas channel includes a reduced portion with a smaller radial dimension adjacent to the outlet. Because the gas can be compressed first at the constriction part and then expanded at the outlet, the pressure at the outlet can be slightly lower than the atmospheric pressure, so it is beneficial for the discharge to dissociate the working gas into plasma.

Another object of the present disclosure is to provide a point-type atmospheric plasma device, the metal casing of which can include a gas curtain device, and can form a gas curtain around the plasma injection port, which can further limit the range of plasma, so it can be more effective Avoid plasma damage to non-treated areas.

According to the above purpose of the present disclosure, a point-type atmospheric plasma device is proposed. The point-type atmospheric plasma device includes a metal casing, metal electrodes, dielectric layers, and gas channels. The metal case has an interior space. The metal electrodes are disposed in the inner space. The dielectric layer is disposed in the inner space and surrounds the outer side of the metal electrode. The central area of the bottom of the dielectric layer has a plasma injection port, and the bottom of the metal electrode is adjacent to the plasma injection port. The gas passage includes a first section, a second section, and a third section. The first section passes through the metal case and the dielectric layer. The second segment is connected to the first segment and extends between the dielectric layer and the outer side of the metal electrode. The third section connects with the second section and is configured to guide the working gas to the plasma injection port.

According to an embodiment of the present disclosure, the above-mentioned third segment penetrates into the metal electrode from the outer side of the metal electrode, and extends from the inside of the metal electrode to the bottom of the metal electrode.

According to an embodiment of the present disclosure, the above-mentioned third segment includes a horizontal portion and a vertical portion. The transverse part traverses through the metal electrode. The vertical part extends longitudinally from the horizontal part to the bottom of the metal electrode.

According to an embodiment of the present disclosure, the above-mentioned point-type atmospheric plasma device further includes a sealing ring, wherein the metal electrode further includes a groove disposed on the outer side of the metal electrode, and the groove is located below the horizontal portion, and the sealing ring is provided in the groove and against the dielectric layer.

According to an embodiment of the present disclosure, the above-mentioned third section includes a first part, a second part, and a third part joined in sequence, and the outlet of the gas channel is located in the third part. The radial dimension of the second portion is smaller than the radial dimension of the first portion and the radial dimension of the third portion.

According to an embodiment of the present disclosure, the above-mentioned second section includes several helical grooves threaded in the outer side of the metal electrode, so as to guide the working gas to the third section along the outer side of the metal electrode.

According to an embodiment of the present disclosure, the above-mentioned metal electrode includes a first part and a second part joined to each other, the second part is between the first part and the dielectric layer, and the third part is between the second part and the dielectric layer Between, wherein the radial dimension of the first part is larger than the radial dimension of the second part.

According to an embodiment of the present disclosure, the aforementioned metal electrode further includes a third portion bonded to the first portion, wherein the radial dimension of the third portion is smaller than the radial dimension of the first portion.

According to an embodiment of the present disclosure, the metal casing further includes an air curtain device. The air curtain device is adjacent to the plasma injection port and configured to form an air curtain around the plasma injection port.

According to an embodiment of the present disclosure, the above-mentioned air curtain device is an air suction device or an air intake device.

Please refer to FIG. 1 , wherein FIG. 1 is a schematic cross-sectional view of a point-type atmospheric plasma device according to an embodiment of the present disclosure. The point-type atmospheric plasma device 100 may be a dielectric discharge atmospheric plasma device. The point-type atmospheric plasma device 100 is suitable for cleaning and etching workpieces because the plasma is more concentrated. The point-type atmospheric plasma device 100 mainly includes a metal shell 110 , a metal electrode 120 , a dielectric layer 130 , and a gas channel 140 .

The shape of the metal casing 110 can be designed according to the process or environmental requirements. For example, the metal casing 110 can be a rectangular, square, or cylindrical hollow shell. As shown in FIG. 1 , the metal casing 110 has an inner space 112 . The inner space 112 of the chamber 112 can accommodate the metal electrode 120 and the dielectric layer 130 . Furthermore, the main part of the gas channel 140 is located in the inner space 112 .

The metal electrode 120 can be a long columnar structure. For example, the metal electrode 120 can be a cylindrical-like structure. The metal electrode 120 is disposed in the inner space 112 of the metal casing 110 . In some embodiments, the metal electrode 120 can be disposed along the height direction HD of the metal casing 110 , that is, the length direction LD of the metal electrode 120 is substantially parallel to the height direction HD of the metal casing 110 . The metal electrode 120 has a top 120a and a bottom 120b facing each other, and an outer side 120c joined between the top 120a and the bottom 120b. The top 120 a of the metal electrode 120 is bonded to the metal casing 110 . The material of the metal electrode 120 can be any suitable metal, such as stainless steel, aluminum, and platinum.

The dielectric layer 130 is also disposed in the inner space 112 of the metal shell 110 and surrounds the outer side 120 c of the metal electrode 120 . Therefore, the dielectric layer 130 can be a hollow columnar structure, and the metal electrode 120 is penetrated in the dielectric layer 130 . The dielectric layer 130 has a bottom 130a. In this embodiment, as shown in FIG. 1 , the central region 130 c of the bottom 130 a of the dielectric layer 130 is provided with a plasma injection port 132 , and the bottom 120 b of the metal electrode 120 is adjacent to the plasma injection port 132 . In this embodiment, the dielectric layer 130 also covers the outer periphery of the bottom 120 b of the metal electrode 120 . That is, the bottom 130a of the dielectric layer 130 extends below the outer periphery of the bottom 120b of the metal electrode 120 such that the metal electrode 120 is located above the bottom 130a of the dielectric layer 130 . In an embodiment where the metal electrode 120 is a cylinder-like structure, the dielectric layer 130 may be a circular tube structure, such as a quartz tube.

The gas channel 140 can guide the working gas from the outside of the point-type atmospheric plasma device 100 through the metal casing 110 , the dielectric layer 130 , and the metal electrode 120 to the plasma injection port 132 of the dielectric layer 130 . In some embodiments, as shown in FIG. 1 , the gas channel 140 includes a first segment 142 , a second segment 144 , and a third segment 146 . The first section 142 can pass through the metal casing 110 and the dielectric layer 130 from the outer side of the metal casing 110 , for example, transversely. The second section 144 is connected to the first section 142 to be in fluid communication with the first section 142 . The second segment 144 can extend longitudinally downward from the first segment 142 between the dielectric layer 130 and the outer side 120 c of the metal electrode 120 . The third section 146 is connected to the second section 144 in fluid communication with the second section 144 . That is, the first segment 142 , the second segment 144 , and the third segment 146 are sequentially joined. The outlet 140a of the gas channel 140 is located at the end of the third section 146 . The third section 146 is located above the plasma injection port 132 and can guide the working gas in the gas channel 140 to the plasma injection port 132 .

Please refer to FIG. 1 and FIG. 2A at the same time, wherein FIG. 2A is a schematic cross-sectional view of a metal electrode of a point-type atmospheric plasma device according to an embodiment of the present disclosure. In this embodiment, the third section 146 of the gas channel 140 penetrates into the metal electrode 120 from the outer side 120c of the metal electrode 120 , and further extends longitudinally from the inside of the metal electrode 120 downward to the bottom 120b of the metal electrode 120 . In some embodiments, as shown in FIG. 2A , the third segment 146 includes a transverse portion 146 a and a vertical portion 146 b. The transverse portion 146 a can transversely penetrate the metal electrode 120 from the outer side surface 120 c of the metal electrode 120 . The top surface of the vertical portion 146b can be connected to the horizontal portion 146a , and can longitudinally extend downward from the horizontal portion 146a to the bottom 120b of the metal electrode 120 . For example, the vertical portion 146b may be joined to the middle region of the horizontal portion 146a, so that the cross-sectional shape of the vertical portion 146b and the horizontal portion 146a is T-like.

In some embodiments, as shown in FIGS. 1 and 2A , the point-type atmospheric plasma device 100 further includes a sealing ring 150 . In addition, the metal electrode 120 further includes a groove 122 . The groove 122 is recessed in the outer side surface 120c of the metal electrode 120, and the groove 122 is located below the horizontal portion 146a. The sealing ring 150 is disposed in the groove 122 and abuts against the dielectric layer 130 . That is to say, the sealing ring 150 is disposed on the outer side surface 120c of the metal electrode 120 and interposed between the metal electrode 120 and the dielectric layer 130 . Thereby, the sealing ring 150 can seal one end of the second section 144 to prevent the working gas from flowing out from this end of the second section 144 . In this way, the working gas in the second section 144 can be forced to flow toward the transverse portion 146a of the third section 146 above the sealing ring 150, so that the working gas can be further guided by the vertical portion 146b to flow between the vertical portion 146b. The plasma injection port 132 below.

Through the gas passage 140, the working gas can be directly guided to the bottom 120b of the metal electrode 120 adjacent to the plasma injection port 132, so that the working gas can be concentrated near the plasma injection port 132 before being discharged and dissociated into plasma. Therefore, the plasma can be more focused, the formed plasma is closer to the workpiece to be processed, and the plasma energy can be confined to a smaller area, which can accurately and efficiently etch the material of the workpiece or remove the contamination on the workpiece thing.

Please refer to FIG. 2B , which is a schematic cross-sectional view of a metal electrode of another point-type atmospheric plasma device according to an embodiment of the present disclosure. The structure of the metal electrode 120' is substantially the same as that of the above-mentioned metal electrode 120. The difference between metal electrodes 120' and 120 is that the third segment 146'

The longitudinal portion 146b' of the third section 146' includes a first portion p1, a second portion p2, and a third portion p3 joined in sequence. Specifically, the second portion p2 is located between the first portion p1 and the third portion p3, and opposite ends of the second portion p2 are joined to the first portion p1 and the third portion p3 respectively. The outlet 140a is located in the third part p3. The radial dimension of the second portion p2 is smaller than the radial dimension of the first portion p1 and also smaller than the radial dimension of the third portion p3.

When the working gas flows from the first part p1 into the second part p2, it is compressed because the radial dimension of the second part p2 is small. When the working gas then flows from the second part p2 into the third part p3, an expansion effect is produced because the radial dimension of the third part p3 is larger than that of the second part p2. In this way, the air pressure at the outlet 140a of the third part p3 can be slightly lower than the atmospheric pressure, that is, the density of gas molecules at the outlet 140a is lower, which is conducive to the discharge to dissociate the working gas into plasma, and can reduce the electric current. pulp attenuation.

Please refer to FIG. 1 again, in some embodiments, the metal casing 110 further includes an air curtain device 190 . The air curtain device 190 can be disposed on the bottom of the metal casing 110 and adjacent to the plasma injection port 132 . The air curtain device 190 can form an air curtain around the periphery of the plasma injection port 132 . The air curtain can limit the scope of the plasma, and can effectively prevent the plasma from damaging the non-treatment area. The air curtain device 190 may be an air suction device or an air intake device.

Please refer to FIG. 3 and FIG. 4 , wherein FIG. 3 is a schematic cross-sectional view of a point-type atmospheric plasma device according to another embodiment of the present disclosure, and FIG. 4 is a schematic diagram of a point-type atmospheric plasma device according to another embodiment of the present disclosure. Schematic side view of the metal electrodes of the dot-type atmospheric plasma device. Similar to the structure of the aforementioned point-type atmospheric plasma device 100 , the point-type atmospheric plasma device 100 a mainly includes a metal shell 110 , a metal electrode 160 , a dielectric layer 170 , and a gas channel 180 . The difference between the point-type atmospheric plasma devices 100a and 100 is that the design of the metal electrode 160 and the gas channel 180 is different from that of the metal electrode 120 and the gas channel 140 . The structure of the dielectric layer 170 is modified in response to changes in the design of the metal electrodes 160 and gas channels 180 .

The metal electrode 160 can also be a long columnar structure. For example, the metal electrode 160 can be a cylindrical-like structure. The metal electrode 160 can also be disposed along the height direction HD of the metal case 110 , so the length direction LD1 of the metal electrode 160 can be substantially parallel to the height direction HD of the metal case 110 . The metal electrode 160 has a top 160a and a bottom 160b opposite to each other, and an outer side 160c joined between the top 160a and the bottom 160b. The top 160 a of the metal electrode 160 is bonded to the metal case 110 . The material of the metal electrode 160 can be any suitable metal, such as stainless steel, aluminum, and platinum.

The dielectric layer 170 is disposed in the inner space 112 of the metal shell 110 and surrounds the outer side 160 c of the metal electrode 160 . For example, the dielectric layer 170 can be a hollow columnar structure, and the metal electrode 160 is penetrated in the dielectric layer 170 . In this embodiment, as shown in FIG. 3 , the bottom 160b of the metal electrode 160 is penetrated in the bottom 170a of the dielectric layer 170, and there is a slit between the metal electrode 160 and the dielectric layer 170. The central region 170c of the bottom 170a of the dielectric layer 170 at the periphery of the outer side 160c of the dielectric layer 160 forms a plasma injection port 172 . Therefore, the dielectric layer 170 does not cover the bottom 160 b of the metal electrode 160 . The dielectric layer 170 can be, for example, a circular tube structure, such as a quartz tube.

The gas channel 180 can guide the working gas from the outside of the point-type atmospheric plasma device 100 a through the metal casing 110 and the dielectric layer 170 to the plasma injection port 172 of the dielectric layer 170 . As shown in FIG. 3 , similar to the gas channel 140 of the above-mentioned embodiment, the gas channel 180 includes a first section 182 , a second section 184 , and a third section 186 which are sequentially connected and in fluid communication with each other. The first segment 182 can pass through the metal casing 110 and the dielectric layer 170 from the outer side of the metal casing 110 , for example, transversely. The second segment 184 extends between the dielectric layer 170 and the outer side 160 c of the metal electrode 160 . The second section 184 includes several helical grooves 184a screwed in the outer side 160c of the metal electrode 160, whereby the helical grooves 184a can guide the working gas flowing from the first section 182 along the outer side 160c of the metal electrode 160 To the third paragraph 186. The outlet 180a of the gas channel 180 is located at the end of the third section 186 .

In some embodiments, as shown in FIGS. 3 and 4 , the metal electrode 160 includes a first portion 162 and a second portion 164 joined to each other. A second section 184 of the gas channel 180 is between the first portion 162 and the dielectric layer 170 , and a third section 186 is between the second portion 164 and the dielectric layer 170 . In some exemplary embodiments, the radial dimension of the first portion 162 is greater than that of the second portion 164 , that is, the second portion 164 is thinner than the first portion 162 . The radial dimension described herein may be, for example, a diameter.

By reducing the radial dimension of the second portion 164 adjacent to the plasma injection port 172, the range of the working gas can be reduced, so that the plasma formed by dissociation of the working gas is more concentrated. Therefore, the point-type atmospheric plasma device 100a can perform plasma treatment on workpieces accurately and efficiently.

In some embodiments, the metal electrode 160 further includes a third portion 166 bonded to the first portion 162 . Specifically, the third part 166 and the second part 164 are connected to two opposite ends of the first part 162 respectively. The radial dimension of the third portion 166 is smaller than the radial dimension of the first portion 162 . As shown in FIG. 4 , the radial dimension difference between the third portion 166 and the first portion 162 can form a gas ring 166 a in the third portion 166 . The gas annulus 166a is in fluid communication with all of the helical grooves 184a and the gas annulus 166a is also in fluid communication with the first section 182 of the gas channel 180 . The working gas flowing into the gas ring 166a from the first section 182 can flow into all the spiral grooves 184a almost simultaneously. In this way, not only the transmission efficiency of the working gas can be improved, but also the uniformity of the gas distribution of the plasma injection port 172 can be improved.

The gas channel 180 can guide the working gas to the plasma injection port 172, so that the plasma can be more focused, and most of the plasma can be formed closer to the workpiece to be processed. Therefore, the plasma energy can be confined to a smaller area, and then the material of the workpiece can be etched accurately and efficiently or the pollutants on the workpiece can be removed.

It can be seen from the above-mentioned embodiments that one advantage of the present disclosure is that the gas channel of the point-type atmospheric plasma device of the present disclosure can directly guide the working gas to the plasma injection port in the central region of the bottom of the dielectric layer. In this way, most of the working gas can be dissociated near the plasma injection port to form plasma. Therefore, the formation of plasma in the inner space of the metal shell can be greatly reduced, which can not only avoid unnecessary waste of power, but also make the plasma more concentrated and closer to the workpiece to be treated, thereby improving the plasma treatment effect.

Another advantage of the present disclosure is that because the outlet section of the gas flow channel of the point-type atmospheric plasma device of the present disclosure can be penetrated in the metal electrode, it can avoid the formation of plasma at the outlet section of the gas flow channel, and further Reduce unnecessary waste of power and make plasma more concentrated. Therefore, plasma treatment can be more focused, avoiding damage to non-treated areas.

Another advantage of the present disclosure is that the point-type atmospheric plasma device of the present disclosure can use a sealing ring to surround and abut against the outer side of the dielectric layer to seal the cavity of the metal shell, so it can More effectively avoid the formation of plasma in the chamber.

Another advantage of the present disclosure is that the outlet section of the gas channel of the point-type atmospheric plasma device of the present disclosure includes a reduced portion with a smaller radial dimension adjacent to the outlet. Because the gas can be compressed first at the constriction part and then expanded at the outlet, the pressure at the outlet can be slightly lower than the atmospheric pressure, so it is beneficial for the discharge to dissociate the working gas into plasma.

Another advantage of the present disclosure is that the metal casing of the point-type atmospheric plasma device of the present disclosure can include an air curtain device, and an air curtain can be formed on the periphery of the plasma injection port, which can further limit the range of the plasma, so it can be more effective. Avoid plasma damage to non-treated areas.

Although the present disclosure has been disclosed above with embodiments, it is not intended to limit the present disclosure. Any person with ordinary knowledge in this technical field may make various modifications and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of this disclosure should be defined by the scope of the appended patent application.

100: point type atmospheric plasma device 100a: point type atmospheric plasma device 110: metal casing 112: Internal space 120: metal electrode 120': metal electrode 120a: top 120b: bottom 120c: Outer side 122: Groove 130: dielectric layer 130a: bottom 130c: Central District 132: Plasma Injection Port 140: gas channel 140a: Export 142: first paragraph 144: second paragraph 146: third paragraph 146': third paragraph 146a: horizontal part 146b: vertical part 146b': vertical part 150: sealing ring 160: metal electrode 160a: top 160b: bottom 160c: Outer side 162: Part 1 164: Part Two 166: Part Three 166a: Gas ring 170: dielectric layer 170a: bottom 170c: Central District 172: Plasma injection port 180: gas channel 180a: Export 182: first paragraph 184: second paragraph 184a: spiral groove 186: The third paragraph 190: Air curtain device HD: height direction LD: length direction LD1: Length direction p1: the first part p2: the second part p3: the third part

In order to make the above and other purposes, features, advantages and embodiments of the present disclosure more comprehensible, the accompanying drawings are described as follows: [Fig. 1] is a schematic cross-sectional view of a point-type atmospheric plasma device according to an embodiment of the present disclosure; [ FIG. 2A ] is a schematic cross-sectional view showing a metal electrode of a point-type atmospheric plasma device according to an embodiment of the present disclosure; [ FIG. 2B ] is a schematic cross-sectional view showing a metal electrode of another point-type atmospheric plasma device according to an embodiment of the present disclosure; [ FIG. 3 ] is a schematic cross-sectional view of a point-type atmospheric plasma device according to another embodiment of the present disclosure; and [ FIG. 4 ] is a schematic side view showing a metal electrode of a point-type atmospheric plasma device according to another embodiment of the present disclosure.

100: point type atmospheric plasma device

110: metal casing

112: Internal space

120: metal electrode

120a: top

120b: bottom

120c: Outer side

122: Groove

130: dielectric layer

130a: bottom

130c: Central District

132: Plasma Injection Port

140: gas channel

140a: Export

142: first paragraph

144: second paragraph

146: third paragraph

146a: horizontal part

146b: vertical part

150: sealing ring

190: Air curtain device

HD: height direction

LD: length direction

Claims (10)

A point-type atmospheric plasma device, comprising: A metal casing, wherein the metal casing has an inner space; a metal electrode disposed in the inner space; A dielectric layer is arranged in the inner space and surrounds an outer surface of the metal electrode, wherein a central region of a bottom of the dielectric layer has a plasma injection port, and a bottom of the metal electrode is adjacent to the plasma injection ports; and A gas channel, comprising: a first segment passing through the metal shell and the dielectric layer; a second segment contiguous to the first segment and extending between the dielectric layer and the outer side of the metal electrode; and A third section, connected to the second section, is configured to guide a working gas to the plasma injection port. The point-type atmospheric plasma device as claimed in claim 1, wherein the third segment penetrates the metal electrode from the outer side of the metal electrode, and extends from one of the metal electrodes to the bottom of the metal electrode . The point-like atmospheric plasma device as described in Claim 2, wherein the third paragraph includes: A transverse portion transversely runs through the metal electrode; and A vertical portion extends longitudinally from the horizontal portion to the bottom of the metal electrode. The point-type atmospheric plasma device as described in claim 3, further comprising a sealing ring, wherein the metal electrode further comprises a groove disposed in the outer surface of the metal electrode, and the groove is located on the lateral portion Below, the sealing ring is disposed in the groove and abuts against the dielectric layer. The point-like atmospheric plasma device as described in claim 2, wherein the third section includes a first part, a second part, and a third part joined in sequence, and an outlet of the gas channel is located at the third part. part, and a radial dimension of the second part is smaller than a radial dimension of the first part and a radial dimension of the third part. The point-type atmospheric plasma device as described in claim 1, wherein the second section includes a plurality of spiral grooves screwed in the outer surface of the metal electrode, so as to work along the outer surface of the metal electrode. Gas is directed to this third section. The point-type atmospheric plasma device as claimed in item 6, wherein the metal electrode comprises a first part and a second part joined to each other, the second part is between the first part and the dielectric layer, the The third section is between the second portion and the dielectric layer, wherein a radial dimension of the first portion is greater than a radial dimension of the second portion. The point-type atmospheric plasma device as claimed in claim 7, wherein the metal electrode further includes a third part joined to the first part, wherein a radial dimension of the third part is smaller than the radial dimension of the first part size. The point-type atmospheric plasma device as described in claim 1, wherein the metal casing further includes a gas curtain device, the gas curtain device is adjacent to the plasma injection port, and is configured to form an air curtain around the plasma injection port. air curtain. The point-type atmospheric plasma device as described in Claim 9, wherein the air curtain device is an air suction device or an air intake device.

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