Non-thermal arc plasma generator
Technical Field
The invention belongs to the technical field of plasma generation, and particularly relates to a non-thermal arc plasma generator.
Background
The gas temperature of the arc plasma is generally between that of the hot plasma and that of the cold plasma, so that the arc plasma has the advantages of the hot plasma and the cold plasma, and has been applied to the fields of material surface treatment, natural gas reforming, carbon dioxide cracking and the like due to proper temperature and electron density. However, it is difficult to generate a large area, uniform arc plasma with a low gas temperature, because the arc plasma has a heat-to-shrink effect, simply increasing the power does not achieve a proportional increase as much as the power, and increasing the power also causes an increase in the gas temperature of the plasma, and when many materials are processed, the high temperature tends to damage the materials.
In order to solve the problem of large-area arc plasma, the current solutions are mainly two, the first solution is to use an external magnetic field mode to solve, in a non-thermal arc plasma generator with a coaxial structure, a permanent magnet or an electrified coil is added on the outer side of a cylindrical ground electrode, so that the arc plasma rotates under the action of the magnetic field, and further, cold airflow around the plasma is effectively heated; the second method is to increase the number of electrodes, for example, six blade electrodes are used in the document "Study of 6electrodes marking the discharge configuration", and each pair of blade electrodes is powered by one power source, so as to enlarge the volume of the arc plasma. However, both of these methods have problems in practical use, and the first method is inconvenient in processing a material because most of the plasma is still located between electrodes and a long jet cannot be formed although the volume of the arc plasma is enlarged. In the second method, because a knife-shaped electrode is used, the electrode is seriously ablated, and the service life of the whole plasma generator is short. Furthermore, these two methods do not solve the problem of how to reduce the plasma temperature.
Disclosure of Invention
The invention aims to provide a non-thermal arc plasma generator, which solves the problem that arc plasma with large discharge area, good uniformity and low temperature is difficult to generate in the prior art.
The technical scheme of the invention is that the non-thermal arc plasma generator comprises an arc generator and a driving device; the arc generator comprises a rotary power connection part, a ground electrode assembly, a plurality of high-voltage electrode assemblies and a nozzle; the rotary power connection part comprises an upper fixing part and a lower rotating part, the ground electrode component 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 component, 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 fixing 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 drive the high-voltage electrode component to rotate in the cavity, and the electric arc is formed by spraying the nozzle to form annular plasma.
Preferably, the ground electrode inner cover comprises a first fixed-diameter 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 fixed-diameter circular tube, the first fixed-diameter circular tube and the lower rotating part are coaxially arranged and are connected to the bottom surface of the lower rotating part through a bearing, and the second diameter-expanding circular tube is opposite to the inner wall of the nozzle.
Preferably, the ground electrode outer cover comprises a second sizing circular tube fixed to the upper fixing portion, and a third diameter-expanding circular tube and a third sizing circular tube which are 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 portion, and the nozzle is connected to the bottom end of the third sizing circular tube.
Preferably, the nozzle comprises a first reducing circular tube connected with the bottom end of the ground electrode outer cover and a second reducing circular tube connected with the bottom end of the first reducing circular tube; the bottom end of the second reducing circular tube is flush with the bottom end of the ground electrode inner cover, an annular reducing circular cone tube is formed between the second reducing circular tube and the second expanding circular tube of the ground electrode inner cover, the conicity of the reducing circular cone tube is beta, the beta is 0.05-0.5, and a high-voltage electrode is inserted into the reducing circular cone tube;
the depth of the high-voltage electrode inserted into the reducing conical tube is d1, and the size of d1 is 0-10 mm; 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 20-50 mm.
Preferably, the high-voltage electrode comprises a sizing electrode rod electrically connected with a high-voltage power supply and a high-voltage electrode tip connected to the bottom end of the sizing electrode rod, the high-voltage electrode tip is conical, and the high-voltage electrode tip is inserted into the nozzle.
Preferably, the bottom of the lower rotating part is fixedly provided with a connecting support for mounting the cyclone assembly, the cyclone assembly comprises a cylindrical tubular ceramic ring and a cyclone ring arranged in the ceramic ring, the high-voltage electrode tip is arranged at the bottom of the cyclone ring, and the sizing electrode rod penetrates through the cyclone ring to be electrically connected with the high-voltage electrode tip.
Preferably, the cyclone angle of the cyclone ring is 30-60 degrees, and the cyclone angle is consistent with the rotation direction of the high-voltage electrode assembly; the ceramic ring is connected with an air pipe, the other end of the air pipe is fixed with the lower rotating portion, the sizing electrode rod is connected with a high-voltage wire, and the high-voltage wire is fixed with the lower rotating portion.
Preferably, drive arrangement establishes including the cover gear one on the lower rotating part, gear one is driven through transmission assembly by the servo motor drive, transmission assembly include with gear two of a meshing with the transmission shaft of connection on gear two, the vertical setting of transmission shaft and upper end are stretched out and are fixed with gear three by the ground electrode dustcoat, the servo motor drive three rotatory drives of gear the lower rotating part is rotatory.
Preferably, the number of the high-voltage electrode assemblies is not less than two, the high-voltage electrode assemblies are symmetrically distributed, and the high-voltage electrode of each high-voltage electrode assembly is respectively supplied with power by an independent high-voltage power supply.
The non-thermal arc plasma generator has the beneficial effects that: the high-voltage component is driven to rotate by the driving device, the electric arc generated by the electric arc generator is sprayed out of the nozzle and forms annular plasma along with the rotation, so that the size of the plasma is enlarged, large-area electric arc plasma is generated, a target object in a larger area can be treated, and the temperature of the plasma is effectively controlled.
Drawings
FIG. 1 is a front view of the exterior of a non-thermal arc plasma generator according to the present invention,
FIG. 2 is a front view of the internal structure of a non-thermal arc plasma generator according to the present invention,
figure 3 is an enlarged view of figure 2 at a,
FIG. 4 is a schematic view of a cyclonic ring structure.
Detailed Description
In order to facilitate the understanding of the technical solutions of the present invention for those skilled in the art, the technical solutions of the present invention will be further described with reference to the drawings attached to the specification.
As shown in fig. 1 and 2, the present invention relates to a non-thermal arc plasma generator, which comprises an arc generator 10 and a driving device 20. The arc generator 10 includes a rotary electric connection part 1, a ground electrode assembly 2, a plurality of high voltage electrode assemblies 3, and a nozzle 4. The rotary electric part 1 includes an upper fixing part 11 and a lower rotary part 12. The ground electrode assembly 2 includes a ground electrode inner case 22 and a ground electrode outer case 21 which are coaxially disposed and form a receiving chamber for receiving the high-voltage electrode assembly 3. The nozzle 4 is fixed at the bottom end of the ground electrode outer cover 21, the ground electrode outer cover 21 is fixedly installed with the upper fixing 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 ejected from the nozzle 4 to form annular plasma.
Based on the above technical solution, the high voltage electrode assembly 3 rotates, and the high voltage electrode 31 continuously supplies power during the rotation of the high voltage electrode assembly 3, the high voltage electrode 31 continuously forms an arc, and the arc 100 is ejected by the nozzle 4 to form an annular plasma. Therefore, the plasma position is continuously changed, and the problems of fixed action position and small action area of the target object caused by the fixed position of the plasma are effectively avoided. The high-voltage component is driven to rotate by the driving device, the electric arc generated by the electric arc generator is sprayed out of the nozzle and forms annular plasma along with the rotation, so that the size of the plasma is enlarged, large-area electric arc plasma is generated, a target object in a larger area can be treated, and the temperature of the plasma is effectively controlled.
In the above technical scheme, the driving device 20 drives the high-voltage electrode assembly 3 to rotate, so that the phenomenon that arc plasma can only be generated at a fixed point position in the prior art is changed into annular plasma is solved, and the problem that the arc plasma generator in the prior art is difficult to generate arc plasma with large discharge area and good uniformity is solved. Meanwhile, in the technical scheme, the area of the arc plasma does not need to be enlarged by enlarging power, and the low-temperature state of the arc plasma is ensured.
In the above technical solution, the ground electrode assembly 2 does not move, only the high voltage electrode assembly 3 rotates, the rotating part is small, the structural volume and weight are small, the transmission is facilitated, meanwhile, the reliability of the rotating motion is ensured, the cost of the driving device 20 is reduced, and the stability of the structure of the whole plasma generator is ensured.
As shown in fig. 2, the ground electrode inner cover 22 includes a first fixed-diameter circular tube 221 movably connected to the lower rotating portion 12, and a first diameter-expanding circular tube 222 and a second diameter-expanding circular tube 223 sequentially connected to a bottom end of the first fixed-diameter circular tube 221. The ground electrode inner cover 22 is convenient to reduce the self weight of the ground electrode inner cover 22, reduce the volume of the ground electrode inner cover, increase the volume of the containing cavity formed by the ground electrode outer cover 21 and used for containing the high-voltage electrode assembly 3, facilitate the installation and fixation of the high-voltage electrode assembly 3, and avoid the problems of interference and the like in the rotation of the high-voltage electrode assembly 3. The first constant diameter circular tube 221 is provided coaxially with the lower rotating portion 12 and is connected to the bottom surface of the lower rotating portion 12 through a bearing. The ground electrode inner cover 22 is fixed under its own weight during the rotation of the lower rotating part 12, and the stability of the ground electrode inner cover 22 can be improved due to the structure thereof. The second round pipe 223 is disposed opposite to the inner wall of the nozzle 4 to form an annular region for the insertion of the high voltage electrode 31, and the high voltage electrode 31 rotates around the central axis in the annular region.
As shown in fig. 2, the ground electrode cover 21 includes a second circular sizing pipe 211 fixed to the upper fixing portion 11, and a third circular diameter-enlarging pipe 212 and a third circular diameter-enlarging pipe 213 connected to the bottom end of the second circular sizing pipe 211 in this order. The second sizing cylinder 211 is fixed to the outer wall of the upper fixing portion 11, and the nozzle 4 is connected to the bottom end of the third sizing cylinder 213.
Based on the above technical scheme, the volume of the cavity formed by the third diameter-expanding circular tube 212 and the ground electrode outer cover 21 and used for accommodating the high-voltage electrode assembly 3 is increased, meanwhile, the third diameter-expanding circular tube 213 and the ground electrode inner cover 22 together provide an installation space for the high-voltage electrode assembly 3, and on the other hand, a gas gathering effect can be realized, so that an arc plasma jet can be generated at the position of the nozzle 4, and a long-jet arc plasma can be formed, and the arc plasma extends to the outside of the nozzle 4, so that a larger area of treatment on a target object can be realized, such as material surface treatment, natural gas reforming, carbon dioxide cracking and the like.
As shown in fig. 2, the nozzle 4 includes a first reduced diameter round tube 41 connected to the bottom end of the ground electrode cover 21 and a second reduced diameter round tube 42 connected to the bottom end of the first reduced diameter round tube 41. The bottom end of the second reducing circular tube 42 is flush with the bottom end of the ground electrode inner cover 22, and an annular reducing circular conical tube is formed between the second reducing circular tube 42 and the second expanding circular tube 223 of the ground electrode inner cover 22. The conicity of the reducing conical pipe is beta, the beta is 0.05-0.5, and stable arc plasma is generated when the high-voltage electrode works. The high voltage electrode 31 is inserted into a reduced diameter conical tube. The depth of the high-voltage electrode 31 inserted into the diameter-reduced conical tube is d1, and the size of d1 is 0-10 mm; 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 20-50 mm. The high voltage electrode 31 is installed at a position where it is required to improve the efficiency and capacity of the process by ensuring that a stable arc can be generated and by properly adjusting the length of the discharge nozzle.
As shown in fig. 2 and 3, the high voltage electrode 31 includes a fixed diameter electrode rod 312 electrically connected to a high voltage power supply and a high voltage electrode tip 311 connected to a bottom end of the fixed diameter electrode rod 312, the high voltage electrode tip 311 is conical, and the high voltage electrode tip 31 is inserted into the nozzle 4. The high voltage electrode 23 may be set in a vertical state as shown in fig. 2, or may be set in an inclined state, and the included angle between the central axis of the high voltage electrode tip 311 and the horizontal direction is 0 ° to 90 °. Different installation angles of the high-voltage electrode tip 311 can realize the treatment of different positions on the surface of the material, and the adaptability of the material is improved.
As shown in fig. 3 and 4, the bottom of the lower rotating part 12 is fixedly provided with a connecting bracket 5 for mounting the cyclone assembly 32, the cyclone assembly 32 includes a ceramic ring 322 having a cylindrical tube shape and a cyclone ring 323 disposed in the ceramic ring 322, and the ceramic ring 322 is connected to the connecting bracket 5 through 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 with the high-voltage electrode head 311. The magnitude of the cyclone angle of the cyclone ring 323 is 30-60 degrees, 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 a vortex gas, which increases the contact time of the gas with the high-voltage electrode tip 311 and ensures that more stable gas is generated to generate arc plasma. The ceramic ring 322 is connected with an air pipe 324, the other end of the air pipe 324 is fixed with the lower rotating part 12, the sizing electrode rod 312 is connected with a high-voltage wire 313, and the high-voltage wire 313 is fixed with the lower rotating part 12. A brush is provided between the upper fixing portion 11 and the lower rotating portion 12 to ensure that the electrode mounted on the lower rotating portion 12 can be electrically connected during rotation.
As shown in fig. 2, the driving device 20 includes a first gear 201 sleeved on the lower rotating portion 12, and the first gear 201 is driven by a servo motor 205 through a transmission assembly. The transmission assembly comprises a second gear 202 meshed with the first gear 201 and a transmission shaft 203 connected to the second gear 202, the transmission shaft 203 is vertically arranged, the upper end of the transmission shaft is extended out of the ground electrode outer cover 21, a third gear 204 is fixed on the transmission shaft, and the servo motor 205 drives the third gear 204 to rotate so as to drive the lower rotating part 12 to rotate.
Preferably, the number of the high voltage electrode assemblies 3 is not less than two, and the high voltage electrode assemblies are symmetrically distributed, generally two or three, and are symmetrically arranged with respect to the central axis of the ground electrode housing 21, and the high voltage electrode 31 of each high voltage electrode assembly 3 is respectively supplied with power by an independent high voltage power supply, so as to ensure the voltage stability and form stable arc plasma.
Technical solution of the invention is described above with reference to the accompanying drawings, it is obvious that the specific implementation of the invention is not limited by the above-mentioned manner, and it is within the scope of the invention to adopt various insubstantial modifications of the inventive method concept and technical solution, or to apply the inventive concept and technical solution to other occasions without modification.