A non-thermal arc plasma generator

Abstract

The invention discloses a non-thermal arc plasma generator, comprising an arc generator and a driving device; the arc generator comprises a rotating power connection part, a ground electrode assembly, a plurality of high-voltage electrode assemblies and a nozzle; the rotating power connection part comprises an upper fixed part and a lower rotating part; the ground electrode assembly comprises a ground electrode inner cover and a ground electrode outer cover which are coaxially arranged and form a cavity for accommodating the high-voltage electrode assembly; the nozzle is fixed at the bottom end of the ground electrode outer cover; the ground electrode outer cover is fixedly installed with the upper fixed part; the ground electrode inner cover is movably installed with the lower rotating part; the driving device drives the lower rotating part to rotate and drives the high-voltage electrode assembly to rotate in the cavity; the arc is ejected from the nozzle to form an annular plasma; the non-thermal arc plasma generator of the invention solves the problem that it is difficult to generate arc plasma with a large discharge area, good uniformity and low temperature in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of plasma generation, and more particularly relates to a non-thermal arc plasma generator. Background Art

[0002] The gas temperature of arc plasma is generally between that of hot plasma and cold plasma, so it has the advantages of both. Because of its suitable temperature and electron density, it has been applied in the fields of material surface treatment, natural gas reforming, carbon dioxide cracking, etc. However, it is difficult to produce large-area, uniform arc plasma with low gas temperature, because arc plasma has a heat-to-shrink effect. Simply increasing the power does not increase the power in proportion to the power, and increasing the power will also cause the plasma gas temperature to rise. When processing many materials, high temperature can easily damage the materials.

[0003] In order to solve the problem of large-area arc plasma, there are currently two main solutions. The first solution is to use an external magnetic field to solve it. In a coaxial non-thermal arc plasma generator, a permanent magnet or a powered coil is added to the outside of the cylindrical ground electrode so that the arc plasma rotates under the action of the magnetic field, thereby effectively heating the cold air flow around the plasma; the second method is to increase the number of electrodes. For example, the document "Study of 6electrodes gliding arc discharge configuration" uses six blade electrodes, and each pair of blade electrodes is powered by a power supply to expand the volume of the arc plasma. However, both methods have certain problems in practical applications. In the first method, although the volume of the arc plasma is expanded, most of the plasma is still located between the electrodes, and a long jet cannot be formed, which is inconvenient when processing materials. In the second method, due to the use of knife-shaped electrodes, the electrode ablation is more serious and the life of the entire plasma generator is shorter. In addition, these two methods do not solve the problem of how to reduce the plasma temperature. Summary of the invention

[0004] The object of the present invention is to provide a non-thermal arc plasma generator to solve the problem that it is difficult to generate arc plasma with a large discharge area, good uniformity and low temperature in the prior art.

[0005] The technical solution of the present invention is a non-thermal arc plasma generator, comprising an arc generator and a driving device; the arc generator comprises a rotating power connection part, a ground electrode assembly, a plurality of high-voltage electrode assemblies and a nozzle; the rotating power connection part comprises an upper fixed part and a lower rotating part, the ground electrode assembly comprises a ground electrode inner cover and a ground electrode outer cover which are coaxially arranged and form a cavity for accommodating the high-voltage electrode assembly, the nozzle is fixed at the bottom end of the ground electrode outer cover, the ground electrode outer cover is fixedly installed with the upper fixed part, the ground electrode inner cover is movably installed with the lower rotating part, the driving device drives the lower rotating part to rotate and drives the high-voltage electrode assembly to rotate in the cavity, and the arc is formed by the nozzle ejecting a ring-shaped plasma.

[0006] Preferably, the ground electrode inner cover includes a first sizing circular tube movably connected to the lower rotating part and a first expanding diameter circular tube and a second expanding diameter circular tube connected in sequence to the bottom end of the first sizing circular tube, the first sizing circular tube is coaxially arranged with the lower rotating part and is connected to the bottom surface of the lower rotating part through a bearing, and the second expanding diameter circular tube is arranged opposite to the inner wall of the nozzle.

[0007] Preferably, the ground electrode outer cover comprises a second sizing circular tube fixed to the upper fixing part and a third enlarged diameter circular tube and a third sizing circular tube sequentially connected to the bottom end of the second sizing circular tube, the second sizing circular tube is sleeved and fixed on the outer wall of the upper fixing part, and the nozzle is connected to the bottom end of the third sizing circular tube.

[0008] Preferably, the nozzle comprises a first reduced diameter circular tube connected to the bottom end of the ground electrode outer cover and a second reduced diameter circular tube connected to the bottom end of the first reduced diameter circular tube; the bottom end of the second reduced diameter circular tube is flush with the bottom end of the ground electrode inner cover, and an annular reduced diameter conical tube is formed between the second reduced diameter circular tube and the second expanded diameter circular tube of the ground electrode inner cover, the conicity of the reduced diameter conical tube is β, and the β is 0.05-0.5, and the high voltage electrode is inserted into the reduced diameter conical tube;

[0009] The high-voltage electrode is inserted into the reduced-diameter conical tube to a depth of d1, where d1 is 0 to 10 mm; the distance between the bottom end of the high-voltage electrode and the bottom end of the nozzle is d2, where d2 is 20 to 50 mm.

[0010] Preferably, the high-voltage electrode comprises a sizing electrode rod electrically connected to a high-voltage power supply and a high-voltage electrode head connected to the bottom end of the sizing electrode rod, the high-voltage electrode head is conical, and the high-voltage electrode head is inserted into the nozzle.

[0011] Preferably, a connecting bracket for mounting the cyclone assembly is fixedly provided at the bottom of the lower rotating part. The cyclone assembly includes a cylindrical tubular ceramic ring and a cyclone ring placed inside the ceramic ring. The high-voltage electrode head is arranged at the bottom of the cyclone ring, and a sizing electrode rod passes through the cyclone ring and is electrically connected to the high-voltage electrode head.

[0012] Preferably, the swirl angle of the swirl ring is 30° to 60°, and the swirl angle is consistent with the rotation direction of the high-voltage electrode assembly; an air pipe is connected to the ceramic ring, and the other end of the air pipe is fixed to the lower rotating part; a high-voltage wire is connected to the sizing electrode rod, and the high-voltage wire is fixed to the lower rotating part.

[0013] Preferably, the driving device includes a gear 1 sleeved on the lower rotating part, and the gear 1 is driven by a servo motor through a transmission assembly. The transmission assembly includes a gear 2 meshing with the gear 1 and a transmission shaft connected to the gear 2. The transmission shaft is vertically arranged and the upper end extends out from the ground electrode cover and is fixed with a gear 3. The servo motor drives the gear 3 to rotate, thereby driving the lower rotating part to rotate.

[0014] Preferably, there are no less than two high-voltage electrode assemblies, which are symmetrically distributed, and the high-voltage electrodes of each high-voltage electrode assembly are powered by an independent high-voltage power supply.

[0015] The beneficial effect of a non-thermal arc plasma generator of the technical solution of the present invention is that the high-voltage component is driven to rotate by a driving device, and the arc generated by the arc generator is ejected from a nozzle and forms a ring-shaped plasma as it rotates, so that the size of the plasma is expanded, a large area of ​​arc plasma is generated, and a target object in a larger area can be processed, and the temperature of the plasma is effectively controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an external front view of a non-thermal arc plasma generator according to the technical solution of the present invention.

[0017] Figure 2 This is a front view of the internal structure of a non-thermal arc plasma generator according to the technical solution of the present invention.

[0018] Figure 3 for Figure 2 The enlarged picture of A in the middle.

[0019] Figure 4 Schematic diagram of the cyclone ring structure. DETAILED DESCRIPTION

[0020] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings of the specification.

[0021] like Figure 1 and Figure 2As shown, the technical solution of the present invention is a non-thermal arc plasma generator, including an arc generator 10 and a driving device 20. The arc generator 10 includes a rotating power connection part 1, a ground electrode assembly 2, a plurality of high-voltage electrode assemblies 3 and a nozzle 4. The rotating power connection part 1 includes an upper fixed part 11 and a lower rotating part 12. The ground electrode assembly 2 includes a ground electrode inner cover 22 and a ground electrode outer cover 21 which are coaxially arranged and form a cavity for accommodating the high-voltage electrode assembly 3. The nozzle 4 is fixed to the bottom end of the ground electrode outer cover 21, the ground electrode outer cover 21 is fixedly installed with the upper fixed part 11, and the ground electrode inner cover 22 is movably installed with the lower rotating part 12. The driving device 20 drives the lower rotating part 12 to rotate and drives the high-voltage electrode assembly 3 to rotate in the cavity, and the arc 100 is formed by the nozzle 4 ejecting a ring-shaped plasma.

[0022] Based on the above technical solution, the high-voltage electrode assembly 3 rotates, and the high-voltage electrode 31 is continuously powered during the rotation of the high-voltage assembly 3, and the high-voltage electrode 31 continuously and uninterruptedly forms an arc, and the arc 100 is ejected from the nozzle 4 to form an annular plasma. In this way, the plasma position is continuously changed, which effectively avoids the problem that the position of the plasma generation is fixed, resulting in a fixed position and a small action area on the target object. The high-voltage assembly is driven to rotate by a driving device, and the arc generated by the arc generator is ejected from the nozzle and forms an annular plasma as it rotates, so that the size of the plasma is expanded, and a large area of ​​arc plasma is generated, which can process targets within a larger area, and the temperature of the plasma is effectively controlled.

[0023] In the above technical solution, the high voltage electrode assembly 3 is driven to rotate by the driving device 20, and the arc plasma can only be generated at a fixed point in the prior art to form a ring-shaped plasma, which solves the problem that the arc plasma generator in the prior art is difficult to generate arc plasma with a large discharge area and good uniformity. At the same time, in the technical solution, it is not necessary to increase the power to achieve the expansion of the area of ​​the arc plasma, ensuring the low temperature state of the arc plasma.

[0024] In the above technical solution, the ground electrode assembly 2 does not generate movement, and only the high-voltage electrode assembly 3 rotates. The rotating parts are small, and the structure volume and weight are small, which is convenient for transmission. At the same time, it also ensures the reliability of the rotational movement, reduces the cost of the driving device 20, and ensures the stability of the overall plasma generator structure.

[0025] like Figure 2As shown, the ground electrode inner cover 22 includes a first calibrated circular tube 221 movably connected to the lower rotating part 12 and a first enlarged circular tube 222 and a second enlarged circular tube 223 connected in sequence to the bottom end of the first calibrated circular tube 221. The setting of the ground electrode inner cover 22 is convenient for reducing the weight of the ground electrode inner cover 22 itself, reducing its own volume, increasing the volume of the cavity for accommodating the high-voltage electrode assembly 3 formed with the ground electrode outer cover 21, facilitating the installation and fixation of the high-voltage electrode assembly 3, and avoiding interference and other problems during the rotation of the high-voltage electrode assembly 3. The first calibrated circular tube 221 is coaxially arranged with the lower rotating part 12 and connected to the bottom surface of the lower rotating part 12 through a bearing. In the rotation of the lower rotating part 12, the ground electrode inner cover 22 remains fixed under the action of its own weight. At the same time, the setting of the structure of the ground electrode inner cover 22 can also improve its stability. The second enlarged circular tube 223 is arranged relative to the inner wall of the nozzle 4 to form an annular area, which is convenient for the insertion of the high-voltage electrode 31, and the high-voltage electrode 31 rotates around the central axis in the annular area.

[0026] like Figure 2 As shown, the ground electrode cover 21 includes a second calibrated circular tube 211 fixed to the upper fixing portion 11 and a third enlarged diameter circular tube 212 and a third calibrated circular tube 213 connected in sequence to the bottom end of the second calibrated circular tube 211. The second calibrated circular tube sleeve 211 is fixed on the outer wall of the upper fixing portion 11, and the nozzle 4 is connected to the bottom end of the third calibrated circular tube 213.

[0027] Based on the above technical solution, the setting of the third expanded diameter circular tube 212 increases the volume of the cavity for accommodating the high-voltage electrode assembly 3 formed with the ground electrode outer cover 21. At the same time, the setting of the third calibrated circular tube 213 together with the ground electrode inner cover 22 provides an installation space for the high-voltage electrode assembly 3. On the other hand, it can achieve a gas gathering effect to ensure that an arc plasma jet is generated at the position of the nozzle 4, and a long jet of arc plasma can be formed. The arc plasma extends to the outside of the nozzle 4, which can achieve a larger area of ​​treatment of the target object, such as material surface treatment, natural gas reforming, carbon dioxide cracking, etc.

[0028] like Figure 2As shown, the nozzle 4 includes a first reduced diameter circular tube 41 connected to the bottom end of the ground electrode outer cover 21 and a second reduced diameter circular tube 42 connected to the bottom end of the first reduced diameter circular tube 41. The bottom end of the second reduced diameter circular tube 42 is flush with the bottom end of the ground electrode inner cover 22, and a ring-shaped reduced diameter conical tube is formed between the second reduced diameter circular tube 42 and the second expanded diameter circular tube 223 of the ground electrode inner cover 22. The conicity of the reduced diameter conical tube is β, and β is 0.05-0.5 to ensure that a stable arc plasma is generated when the high-voltage electrode is working. The high-voltage electrode 31 is inserted into the reduced diameter conical tube. The depth of the high-voltage electrode 31 inserted into the reduced diameter conical tube is d1, and the size of d1 is 0-10mm; the distance between the bottom end of the high-voltage electrode 31 and the bottom end of the nozzle 4 is d2, and the size of d2 is 20-50mm. The installation position of the high-voltage electrode 31 ensures that a stable arc can be generated on the one hand, and on the other hand, the arc needs to be ejected from the nozzle with an appropriate length to improve the processing efficiency and capacity.

[0029] like Figure 2 and Figure 3 As shown, the high-voltage electrode 31 includes a sizing electrode rod 312 electrically connected to a high-voltage power supply and a high-voltage electrode head 311 connected to the bottom end of the sizing electrode rod 312. The high-voltage electrode head 311 is conical and is inserted into the nozzle 4. The high-voltage electrode 23 can be arranged as follows Figure 2 The vertical state shown can also be set to an inclined state, and the angle between the central axis of the high-voltage electrode head 311 and the horizontal direction is 0° to 90°. Different installation angles of the high-voltage electrode head 311 can achieve processing of different positions on the material surface and improve its adaptability.

[0030] like Figure 3 and Figure 4 As shown, a connecting bracket 5 for installing a cyclone assembly 32 is fixedly provided at the bottom of the lower rotating part 12. The cyclone assembly 32 includes a cylindrical ceramic ring 322 and a cyclone ring 323 placed in the ceramic ring 322. The ceramic ring 322 and the connecting bracket 5 are connected by an insulating member 321. The high-voltage electrode head 311 is arranged at the bottom of the cyclone ring 323, and the sizing electrode rod 312 passes through the cyclone ring 323 and is electrically connected to the high-voltage electrode head 311. The cyclone angle of the cyclone ring 323 is 30° to 60°, and the cyclone angle is consistent with the rotation direction of the high-voltage electrode assembly 3. The gas passes through the cyclone assembly 32 to generate vortex gas, which increases the contact time between the gas and the high-voltage electrode head 311, ensuring that more and more stable gas is generated to generate arc plasma. The ceramic ring 322 is connected to a gas pipe 324, and the other end of the gas pipe 324 is fixed to the lower rotating part 12. The sizing electrode rod 312 is connected to a high-voltage wire 313, and the high-voltage wire 313 is fixed to the lower rotating part 12. A brush is provided between the upper fixed part 11 and the lower rotating part 12 to ensure that the electrodes mounted thereon can be powered when the lower rotating part 12 is rotating.

[0031] like Figure 2As shown, the driving device 20 includes a gear 1 201 sleeved on the lower rotating part 12, and the gear 1 201 is driven by a servo motor 205 through a transmission assembly. The transmission assembly includes a gear 202 meshing with the gear 1 201 and a transmission shaft 203 connected to the gear 2 202. The transmission shaft 203 is vertically arranged and the upper end extends from the ground electrode cover 21 and is fixed with a gear 3 204. The servo motor 205 drives the gear 3 204 to rotate, thereby driving the lower rotating part 12 to rotate.

[0032] Preferably, there are no less than two high-voltage electrode assemblies 3, and they are symmetrically distributed, generally two or three, and are symmetrically arranged with respect to the central axis of the ground electrode outer cover 21. The high-voltage electrodes 31 of each high-voltage electrode assembly 3 are respectively powered by an independent high-voltage power supply to ensure voltage stability and form a stable arc plasma.

[0033] The technical solution of the present invention is described above in combination with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A non-thermal arc plasma generator, characterized in that: The invention comprises an arc generator and a driving device; the arc generator comprises a rotating power connection part, a ground electrode assembly, a plurality of high-voltage electrode assemblies and a nozzle; the rotating power connection part comprises an upper fixed part and a lower rotating part, the ground electrode assembly comprises a ground electrode inner cover and a ground electrode outer cover which are coaxially arranged and form a cavity for accommodating the high-voltage electrode assembly, the nozzle is fixed at the bottom end of the ground electrode outer cover, the ground electrode outer cover is fixedly installed with the upper fixed part, the ground electrode inner cover is movably installed with the lower rotating part, the driving device drives the lower rotating part to rotate and drives the high-voltage electrode assembly to rotate in the cavity, the arc is formed by the nozzle ejecting a ring-shaped plasma, the ground electrode inner cover comprises a first sizing circular tube movably connected with the lower rotating part and a first diameter expanding circular tube and a second diameter expanding circular tube which are sequentially connected to the bottom end of the first sizing circular tube, the first sizing circular tube is coaxially arranged with the lower rotating part and is connected to the bottom surface of the lower rotating part through a bearing, the second diameter expanding circular tube is connected to the lower rotating part, and the lower rotating part is connected to the lower rotating part through a bearing. The inner walls of the nozzle are arranged relatively to each other, the outer cover of the ground electrode comprises a second sizing circular tube fixed to the upper fixing part and a third enlarged diameter circular tube and a third sizing circular tube connected to the bottom end of the second sizing circular tube in sequence, the second sizing circular tube is sleeved and fixed on the outer wall of the upper fixing part, the nozzle is connected to the bottom end of the third sizing circular tube, the nozzle comprises a first reduced diameter circular tube connected to the bottom end of the outer cover of the ground electrode and a second reduced diameter circular tube connected to the bottom end of the first reduced diameter circular tube; the bottom end of the second reduced diameter circular tube is flush with the bottom end of the inner cover of the ground electrode, and a ring-shaped reduced diameter conical tube is formed between the second reduced diameter circular tube and the second enlarged diameter circular tube of the inner cover of the ground electrode, the taper of the reduced diameter conical tube is β, and β is 0.05-0.5, and the high-voltage electrode is inserted into the reduced diameter conical tube; the depth of the high-voltage electrode inserted into the reduced diameter conical tube is d1, and the size of d1 is 0-10mm; the distance between the bottom end of the high-voltage electrode and the bottom end of the nozzle is d2, and the size of d2 is 20-50mm.

2. A non-thermal arc plasma generator according to claim 1, characterized in that: The high-voltage electrode comprises a sizing electrode rod electrically connected to a high-voltage power supply and a high-voltage electrode head connected to the bottom end of the sizing electrode rod. The high-voltage electrode head is conical and is inserted into a nozzle.

3. The non-thermal arc plasma generator according to claim 1, characterized in that: A connecting bracket for installing a cyclone assembly is fixedly provided at the bottom of the lower rotating part. The cyclone assembly includes a cylindrical ceramic ring and a cyclone ring placed inside the ceramic ring. The high-voltage electrode head is arranged at the bottom of the cyclone ring, and the sizing electrode rod passes through the cyclone ring and is electrically connected to the high-voltage electrode head.

4. A non-thermal arc plasma generator according to claim 3, characterized in that: The swirl angle of the swirl ring is 30°~60°, and the swirl angle is consistent with the rotation direction of the high-voltage electrode assembly; an air pipe is connected to the ceramic ring, and the other end of the air pipe is fixed to the lower rotating part; a high-voltage wire is connected to the sizing electrode rod, and the high-voltage wire is fixed to the lower rotating part.

5. The non-thermal arc plasma generator according to claim 1, characterized in that: The driving device includes a gear 1 sleeved on the lower rotating part, and the gear 1 is driven by a servo motor through a transmission assembly. The transmission assembly includes a gear 2 meshing with the gear 1 and a transmission shaft connected to the gear 2. The transmission shaft is vertically arranged and the upper end extends out from the ground electrode cover and is fixed with a gear 3. The servo motor drives the gear 3 to rotate and drives the lower rotating part to rotate.

6. The non-thermal arc plasma generator according to claim 1, characterized in that: There are no less than two high-voltage electrode assemblies, which are symmetrically distributed, and the high-voltage electrodes of each high-voltage electrode assembly are powered by an independent high-voltage power supply.

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