CN115087184A

CN115087184A - Plasma jet generating device

Info

Publication number: CN115087184A
Application number: CN202210890896.XA
Authority: CN
Inventors: 蒙林; 王彬; 许斌; 李海龙; 殷勇; 袁学松
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2022-07-27
Filing date: 2022-07-27
Publication date: 2022-09-20

Abstract

The invention discloses a plasma jet generating device, which is characterized in that a first insulating layer, a first electrode layer and a plasma accelerating layer are sequentially and tightly connected to a base through screws, a first through hole is formed in the first insulating layer, a second through hole is formed in the first electrode layer, a third through hole is formed in the plasma accelerating layer, and the first through hole, the second through hole and the third through hole are arranged coaxially; the cathode column is inserted between the first through hole and the second through hole; the first insulating layer is also provided with a vent hole; the discharge cavity structure is used for generating plasma jet and emitting the plasma jet outwards; the power supply circuit is used for providing a direct current power supply for the discharge cavity structure; the gas supply structure is used for conveying gas into the first through hole; the plasma jet generating device has the advantages that the discharge process in the discharge cavity cannot be influenced in the plasma jet generating process, and the cathode column is prevented from being ejected.

Description

Plasma jet generating device

Technical Field

The invention relates to the technical field of plasma generation, in particular to a plasma jet generating device.

Background

Plasma (plasma), also known as plasma, is an ionized gaseous substance consisting of positive and negative ions generated by ionization of atoms and radicals after partial electron deprivation, and a macroscopic electrically neutral ionized gas with a dimension larger than the debye length, the movement of which is mainly governed by electromagnetic force and shows remarkable collective behavior, and has wide application in aviation, medical treatment and treatment of polluted waste materials.

In the current plasma jet generation device, gas is generally introduced into a discharge cavity and enters from the tail of the device, but when the plasma jet is generated by introducing gas by adopting the method, the cathode shakes often under the condition that the gas flow introduced from the outside is too large, and the cathode is ejected like a nail even under the action of the gas pressure, so that the discharge process in the discharge cavity is influenced.

In view of this, the present application is specifically made.

Disclosure of Invention

The invention aims to solve the technical problem that in the prior art, when gas is conveyed into a discharge cavity from the tail part of a device, the cathode shakes in the using process under the condition of overlarge gas flow, and the cathode can be ejected like a nail when the cathode shakes seriously.

The invention is realized by the following technical scheme:

a plasma jet generating device comprises a discharge cavity structure, a power supply circuit and a gas supply structure, wherein the discharge cavity structure comprises a base, a first insulating layer, a first electrode layer and a plasma accelerating layer, the first insulating layer, the first electrode layer and the plasma accelerating layer are sequentially and tightly connected to the base through screws, a first through hole is formed in the first insulating layer, a second through hole is formed in the first electrode layer, a third through hole is formed in the plasma accelerating layer, the first through hole, the second through hole and the third through hole are coaxially arranged, and a discharge cavity is formed by the first through hole and the second through hole; the base is also provided with a cathode column, and the cathode column is inserted between the first through hole and the second through hole; the first insulating layer is also provided with a vent hole, and the vent hole is used for conveying gas into the first through hole; the discharge cavity structure is used for generating plasma jet and emitting the plasma jet outwards; the power supply circuit is used for providing a direct current power supply for the discharge cavity structure; the gas supply structure is used for conveying gas into the first through hole.

In a traditional device for generating plasma jet, the plasma jet usually enters a discharge cavity from the tail part of the device and is generated under the action of a cathode column, but when the device is used for generating plasma, when input airflow is too large, the air pressure in the discharge cavity is too large, so that a cathode shakes in the use process, and even the cathode is ejected like a nail under the action of the air pressure; the invention provides a plasma jet generating device, which is characterized in that gas is conveyed from the side surface of a discharge cavity, and the layers of the discharge cavity are tightly connected from top to bottom through screws, so that the impact of the gas flow on each layer is avoided, the discharge process in the discharge cavity cannot be influenced in the plasma jet generating process, and a cathode column is prevented from being ejected.

Preferably, the cathode column includes first cylinder and needle point, the needle point includes first cylinder, second cylinder, cone and round platform, first cylinder one end sets up on the first cylinder, the other end of first cylinder with the lower bottom surface of round platform is connected, the last bottom surface of round platform with second cylinder one end is connected, the other end of second cylinder with the cone bottom surface is connected.

Preferably, the diameter of the upper bottom surface of the circular truncated cone is the same as that of the cross section of the second cylinder, the diameter of the lower bottom surface of the circular truncated cone is the same as that of the cross section of the first cylinder, and the diameter of the cross section of the second cylinder is smaller than that of the cross section of the first cylinder.

Preferably, the plasma accelerating layer comprises a second insulating layer and a second electrode layer, the second electrode layer is arranged on the second insulating layer, the second electrode layer is provided with a first protrusion, and the second insulating layer is provided with a first groove matched with the first protrusion.

Preferably, a buffer chamber is arranged on the third through hole, and the buffer chamber is used for carrying out airflow buffer on the transmitted plasma jet.

Preferably, at least two plasma accelerating layers are arranged in the discharge cavity structure, and a Lava nozzle is arranged at a third through hole in at least one plasma accelerating layer.

Preferably, the first electrode layer is provided with a second protrusion, the second through hole comprises a discharge chamber, a first channel and a second channel, the first channel is communicated with the second channel through the discharge chamber, and the first channel is arranged on the second protrusion; the tip of the needle tip extends into the discharge chamber arrangement.

Preferably, the device is provided with at least three screws, and the bolts uniformly fix and connect the layered main bodies of the discharge cavity structure together.

Preferably, the gas supply structure comprises a flow meter and a gas cylinder, the flow meter is arranged at the outlet of the gas cylinder, and the outlet of the gas cylinder is connected with the vent hole through the flow meter.

Preferably, the first insulating layer and the second insulating layer are both made of ceramic materials.

Compared with the prior art, the invention has the following advantages and beneficial effects:

according to the plasma jet generating device provided by the embodiment of the invention, the gas is conveyed from the side surface into the discharge cavity, and the stages of the discharge cavity are tightly connected from top to bottom through the screws, so that the impact of the gas flow on each stage is avoided, the discharge process in the discharge cavity cannot be influenced in the plasma jet generating process, and the cathode column is prevented from being ejected.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that for those skilled in the art, other related drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a schematic perspective view of the device

FIG. 2 is a cross-sectional view of the apparatus

FIG. 3 is a schematic view of the base and the cathode base

FIG. 4 is a schematic diagram of a power supply circuit

Reference numerals:

1. a second electrode layer; 2. a screw; 3. a Lava nozzle; 4. a second insulating layer; 5. a first electrode layer; 6. a first insulating layer; 7. a base; 8. a vent hole; 9. a first through hole; 10. a needle tip; 11. a first channel; 12. a buffer chamber; 13. a third through hole; 14. a discharge chamber; 15. a first cylinder; 16. a circular truncated cone; 17. a cone; 18. a second cylinder; 19. a first column.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: it is not necessary to employ these specific details to practice the present invention. In other instances, well-known structures, circuits, materials, or methods have not been described in detail so as not to obscure the present invention.

Throughout the specification, reference to "one embodiment," "an embodiment," "one example," or "an example" means: the particular features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the invention. Thus, the appearances of the phrases "one embodiment," "an embodiment," "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "upper", "lower", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore, should not be construed as limiting the scope of the present invention.

The embodiment discloses a plasma jet generating device, this embodiment is to in the device that current plasma jet produced, from the afterbody of device directly to discharging the intracavity conveying gas, if the pressure at afterbody conveying gas is too big, can cause the in-process that plasma jet produced, the negative pole post is unable stable, and probably jets out the negative pole post when serious, consequently, in the device that this embodiment provided, change the input gas into the edgewise input, and will form each level and the zonulae occludens of discharging the cavity through screw 2, under the condition that can not leak gas in guaranteeing to discharge the cavity, guarantee in the in-process that uses the negative pole post, can not produce any influence to the negative pole post.

The schematic diagram of the embodiment is shown in fig. 1 to 4, and includes a discharge cavity structure, a power supply circuit and a gas supply structure, where the discharge cavity structure includes a base 7, a first insulating layer 6, a first electrode layer 5 and a plasma accelerating layer, the first insulating layer 6, the first electrode layer 5 and the plasma accelerating layer are sequentially and tightly connected to the base 7 through screws 2, a first through hole 9 is formed in the first insulating layer 6, a second through hole is formed in the first electrode layer 5, a third through hole 13 is formed in the plasma accelerating layer, the first through hole 9, the second through hole and the third through hole 13 are coaxially arranged, and the first through hole 9 and the second through hole form a discharge cavity; the base 7 is also provided with a cathode column, and the cathode column is inserted between the first through hole 9 and the second through hole; the first insulating layer 6 is further provided with a vent hole 8, and the vent hole 8 is used for conveying gas into the first through hole 9; the discharge cavity structure is used for generating plasma jet and emitting the plasma jet outwards;

the first electrode layer 5 is provided with a second protrusion, the second through hole comprises a discharge chamber 14, a first channel 11 and a second channel, the first channel 11 is communicated with the second channel through the discharge chamber 14, and the first channel 11 is arranged on the second protrusion; the tip of the needle tip 10 is disposed to protrude into the discharge chamber 14, and the discharge chamber 14 is disposed in the first electrode layer 5, mainly by protruding the tip of the needle tip 10 into the discharge chamber 14, and then generating plasma jet in the case of external air flow input.

The first through hole 9, the second through hole and the third through hole 13 form a discharge cavity, the cathode column extends into the first through hole 9 to discharge, and the electrode layers arranged on two sides of the second through hole and the third through hole 13 are used for accelerating the generated plasma jet to be ejected.

The power supply circuit is used for providing a direct current power supply for the discharge cavity structure, and the power supply circuit provided in the embodiment is mainly connected with different electrode layers to realize voltage supply to the electrodes; in this embodiment, as shown in the structure diagram of the adopted power supply circuit, 1 to 5 points in fig. 4 need to be led out through a wire clip and connected to the plasma device in fig. 1. Specifically, the wire clamp in fig. 4 is sequentially connected to different electrode layers in fig. 1, corresponding voltage is provided to the electrode layers through the relation of connected resistor voltage division, when argon is not broken down, argon is provided between the wire clamp 1 and the wire clamp 5, the resistance is large, and current passes through the resistor on the circuit board. At this point, we can observe that the power supply exhibits a small current, roughly the total applied voltage divided by the total resistance of the series resistors. After the argon gas is broken down, plasma is formed, the resistance between the wires 1 and 5 is rapidly reduced, the current basically does not pass through the resistance on the circuit board, the plasma between the wire racks 1 and 5 is directly walked, and the indication of the power current is changed from the mA level to the A level. Whether to break down to form stable plasma can be judged by the current value of the power supply.

The gas supply structure is used for conveying gas into the first through hole 9, in the embodiment, the gas supply structure comprises a flow meter and a gas cylinder, the flow meter is arranged at the outlet of the gas cylinder, the outlet of the gas cylinder is connected with the vent hole 8 through the flow meter, and the flow meter is mainly arranged for controlling the gas pressure input into the first through hole 9 to be within a certain range, so that the gas pressure at the moment of placement is too high, and certain influence is generated on the device;

the third through hole 13 is provided with a buffer chamber 12, the buffer chamber 12 is used for carrying out airflow buffer on the transmitted plasma jet, and the buffer chamber 12 is arranged for the purpose of mainly acting to cause a certain buffer process in the discharge channel when the pressure of the input gas is too large.

The cathode column includes first cylinder and needle point 10, needle point 10 includes first cylinder 15, second cylinder 18, the cone 17 body and

round platform

16, 15 one end of first cylinder sets up on the first cylinder, the other end of first cylinder 15 with the lower bottom surface of round platform 16 is connected, the last bottom surface of round platform 16 with 18 one end of second cylinder are connected, the other end of second cylinder 18 with the cone 17 bottom surface is connected, in this embodiment, utilizes the principle of point discharge, designs the negative pole into echelonment needle point 10, can prevent that needle point 10 from splitting, conveniently discharges simultaneously. When plasma discharges, argon is broken through, large current is generated instantly, and the needle point 10 is melted and blackened, so that a layer of iron and nickel can be electroplated by tungsten metal in the selection of materials, and the material has the advantages of good conductivity, high temperature resistance, high hardness and oxidation resistance.

The diameter of the upper bottom surface of the circular truncated cone 16, the diameter of the bottom surface of the cone 17 and the diameter of the cross section of the second cylinder 18 are the same, the diameter of the lower bottom surface of the circular truncated cone 16 is the same as the diameter of the cross section of the first cylinder 15, and the diameter of the cross section of the second cylinder 18 is smaller than the diameter of the cross section of the first cylinder 15. Set up the pointed end into the structure of ladder shape, the hardness of needle point 10 can be a bit bigger, and very easy needle point 10 is blown, and is also big with the argon gas contact surface, and the effect of discharging can be better, and most pointed material chooses for use tungsten, then utilizes electroplating technique to make up a layer film, prevents its oxidation.

The plasma accelerating layer comprises a second insulating layer 4 and a second electrode layer 1, the second electrode layer 1 is arranged on the second insulating layer 4, the second electrode layer 1 is provided with a first protrusion, the second insulating layer 4 is provided with a first groove matched with the first protrusion, at least two plasma accelerating layers are arranged in the discharge cavity structure, and a Lava spray pipe 3 is arranged in a third through hole 13 in at least one plasma accelerating layer.

In the plasma accelerating layer, the second electrode layer 1 is arranged to mainly accelerate and extract the generated plasma in the plasma channel. The material is made of brass, and the electrode is provided with a special terminal which is conveniently connected with a lead frame 2-4 in figure 4 and is added with a Laval nozzle design for increasing the gas flow rate and leading out plasma to form a bullet shape. The diameters of plasma channels in front of and behind the Laval nozzle are different, and the diameter of the gas outlet is slightly larger than that of the gas inlet.

In this embodiment, the device is provided with at least three screws 2, the bolts uniformly fix and connect the layered main body of the discharge cavity structure together, the number of the screws 2 is at least three, but not limited to three, and is defined according to the size and the structure of the layers, the layers are tightly connected through the screws 2, so that the gas leakage in the plasma jet generation process is avoided, and the screws 2 are nylon screws 2.

In this embodiment, the first insulating layer 6, the material of second insulating layer 4 is ceramic material, sets up the insulating layer into ceramic material's lamellar structure, and mainly the pottery can give out the heat that the electrode produced in the effect process when insulating, avoids the temperature of device to appear too high the condition, and the material chooses for use pottery, and high temperature resistant and hardness is higher to it is insulating, effectively keeps apart the upper and lower level.

The specific implementation mode is as follows:

the power supply is preheated for 1min to stabilize the generated voltage. The device is firstly filled with argon, the air in the device is exhausted, the whole channel is filled with argon, and the electrode is effectively protected. The fluidic device is then energized, gradually increasing the voltage, at which time plasma chemical reactions occur within the discharge chamber 14. The argon atoms forming the excited state collide with electrons and then ionize charged particles. The charged particles are accelerated by the action of the electric field applied by the middle electrode and the drive of the argon gas flow. Meanwhile, the laval nozzle can be used for accelerating the airflow from subsonic speed to supersonic speed. The portion of the charged particles is pulled out of the plasma channel to form a plasma jet. When the plasma is excited, a sharp jet buzzer is generated, and then a stable jet flow is formed, and the color is red. After the plasma has stabilized, we can change the distance of the tip 10 to see if the jet length has changed and test the plasma jet with paper, meat, etc. to see if it can cut, thereby reflecting the electron energy.

The plasma jet generating device disclosed by the embodiment is characterized in that gas is conveyed in the discharge cavity from the side surface, and the screw 2 is used for tightly connecting the discharge cavity from top to bottom, so that the impact of gas flow on each level is avoided, the discharge process in the discharge cavity cannot be influenced in the process of plasma jet generation, and the cathode column is prevented from being ejected.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The plasma jet generating device is characterized by comprising a discharge cavity structure, a power supply circuit and a gas supply structure, wherein the discharge cavity structure comprises a base (7), a first insulating layer (6), a first electrode layer (5) and a plasma accelerating layer, the first insulating layer (6), the first electrode layer (5) and the plasma accelerating layer are sequentially and tightly connected to the base (7) through screws (2), a first through hole (9) is formed in the first insulating layer (6), a second through hole is formed in the first electrode layer (5), a third through hole (13) is formed in the plasma accelerating layer, the first through hole (9), the second through hole and the third through hole (13) are coaxially arranged, and a discharge cavity is formed by the first through hole (9) and the second through hole; the base (7) is also provided with a cathode column, and the cathode column is inserted between the first through hole (9) and the second through hole; the first insulating layer (6) is further provided with a vent hole (8), and the vent hole (8) is used for conveying gas into the first through hole (9); the discharge cavity structure is used for generating plasma jet and emitting the plasma jet outwards; the power supply circuit is used for providing a direct-current power supply for the discharge cavity structure; the gas supply structure is used for conveying gas into the first through hole (9).

2. The plasma jet generating device according to claim 1, wherein the cathode column comprises a first column body and a needle tip (10), the needle tip (10) comprises a first cylinder (15), a second cylinder (18), a cone (17) and a circular truncated cone (16), one end of the first cylinder (15) is arranged on the first column body, the other end of the first cylinder (15) is connected with the lower bottom surface of the circular truncated cone (16), the upper bottom surface of the circular truncated cone (16) is connected with one end of the second cylinder (18), and the other end of the second cylinder (18) is connected with the bottom surface of the cone (17).

3. A plasma jet generating device according to claim 2, characterized in that the diameter of the upper base of said circular truncated cone (16), the diameter of the base of said cone (17) and the diameter of the cross-section of said second cylinder (18) are the same, the diameter of the lower base of said circular truncated cone (16) is the same as the diameter of the cross-section of said first cylinder (15), and the diameter of the cross-section of said second cylinder (18) is smaller than the diameter of the cross-section of said first cylinder (15).

4. A plasma jet generating device according to claim 1, characterized in that said plasma accelerating layer comprises a second insulating layer (4) and a second electrode layer (1), said second electrode layer (1) is disposed on said second insulating layer (4), said second electrode layer (1) is provided with a first protrusion, said second insulating layer (4) is provided with a first groove matching with said first protrusion.

5. A plasma-jet generating device according to claim 4, characterized in that a buffer chamber (12) is provided in the third through-hole (13), said buffer chamber (12) being adapted to buffer the flow of the transported plasma jet.

6. A plasma jet generating device as claimed in claim 4, characterized in that at least two plasma accelerating layers are arranged in the discharge chamber structure, and the third through hole (13) in at least one plasma accelerating layer is provided with a Lava nozzle (3).

7. A plasma-jet generating device according to claim 2, characterized in that the first electrode layer (5) is provided with a second protrusion, the second through-hole comprises a discharge chamber (14), a first channel (11) and a second channel, the first channel (11) is arranged in communication with the second channel through the discharge chamber (14), and the first channel (11) is arranged on the second protrusion; the tip of the needle tip (10) is arranged to extend into the discharge chamber (14).

8. A plasma jet generating device according to any of claims 2 to 7, characterized in that at least three screws (2) are provided, and the screws uniformly fix the layered body of the discharge chamber structure together.

9. A plasma-jet generating device according to claim 8, characterized in that the gas supply structure comprises a flow meter and a gas cylinder, the flow meter is arranged at the outlet of the gas cylinder, and the outlet of the gas cylinder is connected with the vent hole (8) through the flow meter.

10. A plasma-jet generating device according to claim 4, characterized in that the first insulating layer (6) and the second insulating layer (4) are made of ceramic.