Electrode for plasma discharge and air purification device

Abstract

The invention discloses an electrode for plasma discharge and an air purification device. The electrode for plasma discharge comprises an inner electrode and an outer electrode, the outer electrodes are spirally wound on the outer side of the inner electrode, the number of the outer electrodes is at least two, the ends of all the outer electrodes are connected, the diameters, the lengths and the spiral intervals of all the outer electrodes are equal, the diameter of each outer electrode is d1, and d1 is larger than or equal to 0.001 mm and smaller than or equal to 9 mm. According to the electrode, the outer electrodes are spirally wound on the outer side of the inner electrode, the diameters, the lengths and the spiral spacing sizes of all the outer electrodes are designed to be the same, and the diameters of the outer electrodes are designed to range from 0.001 mm to 0.9 mm, so that the resistance of the single outer electrode is reduced to a proper value, and compared with a traditional electrode, the resistance of the single outer electrode is reduced to a proper value under the condition of the same discharge area. And the heat loss generated in the whole electrode discharge process is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of electrode structures, and in particular to an electrode for plasma discharge and an air purification device. Background Art

[0002] In recent years, plasma discharge technology has been widely used in the fields of exhaust gas treatment and air purification. It is a relatively efficient way to treat waste gas. Plasma, also known as plasma, is an ionized gaseous substance with a large number of positive and negative ions produced by the ionization of atoms and atomic groups after some electrons have been deprived. It has a high energy level and activity. The principle of plasma discharge treatment is to rely on the plasma generated by ionization to decompose pollutants in exhaust gas or air, thereby achieving the effect of degrading pollutants and purifying the air. Electrodes play a vital role in plasma discharge. Electrodes are key components for generating and maintaining plasma. Factors such as their shape, size, and material will directly affect the generation, transmission, and stability of plasma. The heat loss generated during plasma discharge is a complex process. The electrodes commonly used in plasma discharge applications are mostly composed of an internal electrode and an external electrode arranged on the outside of the internal electrode. In order to meet the requirements of plasma discharge, the diameter of the external electrode is usually designed to be larger, but the overall resistance of the external electrode is also larger, and the heat loss generated by the external electrode during plasma discharge is also larger. Although physical cooling and other methods can reduce the impact of electrode heat loss on discharge, it is impossible to reduce the power of electrode heat loss. Therefore, traditional electrodes have large heat loss during plasma discharge, resulting in excessive useless power consumption of the power supply and low overall energy efficiency. Summary of the invention

[0003] The embodiments of the present invention provide an electrode for plasma discharge and an air purification device, aiming to solve the problem of large heat loss in the discharge process of a conventional electrode.

[0004] In a first aspect, an embodiment of the present invention provides an electrode for plasma discharge, comprising:

[0005] Internal electrode;

[0006] The outer electrode is spirally wound on the outer side of the inner electrode. There are at least two outer electrodes, and the ends of all the outer electrodes are connected. The diameter, length and spiral pitch of all the outer electrodes are equal. The diameter of the outer electrode is d1, where 0.001mm≤d1≤9mm.

[0007] In the electrode for plasma discharge provided by an embodiment of the present invention, the outer side of the inner electrode is wrapped with an insulating layer, and the outer electrode is spirally wound on the surface of the insulating layer, wherein the thickness of the insulating layer is L1, wherein 0.001mm≤L1≤80mm.

[0008] In the electrode for plasma discharge provided by the embodiment of the present invention, the insulating layer is made of ceramic material, and the length of the insulating layer in the axial direction of the inner electrode is L2, wherein L2=0.5 mm.

[0009] In the electrode for plasma discharge provided in the embodiment of the present invention, the diameter of the inner electrode is d2, wherein 0.001 mm≤d2≤100 mm.

[0010] In the electrode for plasma discharge provided by the embodiment of the present invention, the inner electrode is a nickel-plated metal wire, and d2=1 mm.

[0011] In the electrode for plasma discharge provided by the embodiment of the present invention, all the outer electrodes are distributed at equal intervals in the axial direction of the inner electrode.

[0012] In the electrode for plasma discharge provided by the embodiment of the present invention, the spiral pitch of each of the outer electrodes is s, wherein 0.04 mm≤s≤40 mm.

[0013] In the electrode for plasma discharge provided by the embodiment of the present invention, the distance between the threads of two adjacent outer electrodes in the axial direction of the inner electrode is s1, wherein 0.05 mm≤s1≤10 mm.

[0014] In a second aspect, an embodiment of the present invention provides an air purification device, which includes the electrode for plasma discharge described in the first aspect.

[0015] The embodiment of the present invention provides an electrode for plasma discharge and an air purification device, wherein the electrode for plasma discharge includes an inner electrode and an outer electrode, wherein the outer electrode is spirally wound on the outer side of the inner electrode, and at least two outer electrodes are provided, and the ends of all the outer electrodes are connected, and the diameter, length and spiral pitch of all the outer electrodes are equal, and the diameter of the outer electrode is d1, wherein 0.001mm≤d1≤9mm. The electrode of the present application is formed by spirally winding a plurality of outer electrodes on the outer side of the inner electrode, and the diameter, length and spiral pitch of all the outer electrodes are designed to be the same, and the diameter of the outer electrode is designed to be in the range of 0.001mm to 0.9mm, so that the resistance of a single outer electrode is reduced to a suitable value, and compared with the traditional electrode, under the condition of the same discharge area, the heat loss generated during the entire electrode discharge process is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of the structure of an electrode provided by an embodiment of the present invention;

[0018] Figure 2 Another schematic diagram of the structure of the electrode provided by the embodiment of the present invention;

[0019] Figure 3 A cross-sectional view of an electrode provided by an embodiment of the present invention;

[0020] Figure 4 An axial cross-sectional view of an electrode provided by an embodiment of the present invention;

[0021] Figure 5 An equivalent circuit diagram of an electrode provided by an embodiment of the present invention;

[0022] Figure 6 Another axial cross-sectional view of the electrode provided by an embodiment of the present invention.

[0023] The reference numerals in the figures are:

[0024] 10. Inner electrode; 20. Outer electrode; 30. Insulating layer. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, but are not used to limit the present invention. In addition, in the drawings, structures with similar or identical structures are represented by the same reference numerals.

[0027] In order to facilitate understanding of the present invention, the electrode for plasma discharge provided by the embodiment of the present invention is first described. Figures 1 to 6The electrode for plasma discharge includes an inner electrode 10 and an outer electrode 20; the outer electrode 20 is spirally wound on the outer side of the inner electrode 10, and at least two outer electrodes 20 are provided, and the ends of all the outer electrodes 20 are connected, and the diameters, lengths and spiral pitches of all the outer electrodes 20 are equal, and the diameter of the outer electrode 20 is d1, wherein 0.001mm≤d1≤9mm.

[0028] The traditional electrode consists of an inner electrode and an outer electrode, and the outer electrode is arranged outside the inner electrode. In order to meet the discharge requirements of the electrode, the size of the outer electrode is usually designed to be relatively large, so the resistance is also relatively large. Since the heat loss generated by plasma discharge is positively correlated with the resistance, the greater the resistance, the more heat is generated during the discharge process of the electrode. Therefore, when the traditional electrode is discharged, the heat loss generated is relatively large, resulting in large power loss of the power supply during the discharge process and more useless power. For this reason, the present invention proposes an electrode for plasma discharge, which aims to solve the problem of large heat loss of traditional electrodes during the discharge process. The specific ideas are as follows:

[0029] The types of plasma discharge can be divided into arc discharge, corona discharge, DBD (dielectric barrier discharge) and glow discharge according to the form of plasma generation. The electrode in this embodiment can be used in any of the above discharge types. The electrode in this embodiment mainly consists of an inner electrode 10 and at least two outer electrodes 20. The inner electrode 10 is a cylindrical structure, and the outer electrode 20 is a cylindrical filament structure, such as Figure 2 As shown, the number of the outer electrodes 20 is set to at least two, all of the outer electrodes 20 are spirally wound on the outside of the inner electrode 10, and the outer electrodes 20 are spirally extended in the axial direction of the inner electrode 10 as a whole. The outer electrodes 20 can effectively increase the discharge area by spirally winding. The ends of all the outer electrodes 20 outside the inner electrode 10 are connected by welding to form a parallel structure. Specifically, each outer electrode 20 has two ends, such as Figure 5As shown, one end of each of the external electrodes 20 is welded together to be connected to the positive or negative pole of the power supply through a wire, and the other ends of each of the external electrodes 20 are also welded together to form a parallel connection, and cooperate with the power supply and the internal electrode 10 to form a loop during discharge. When one of the external electrodes 20 is broken, the remaining external electrodes 20 can still discharge normally, so the failure rate can be reduced and the reliability of electrode discharge can be improved. At the same time, multiple external electrodes 20 are connected in parallel to replace a single external electrode of a traditional electrode, and the area of ​​the power supply connection of the external electrode 20 is expanded, which is convenient for welding and connection, and can reduce the problem of abnormal discharge caused by unstable welding points. The diameter, length and spiral pitch of all external electrodes 20 are designed to be equal, that is, the shape and size of all external electrodes 20 are the same, and all external electrodes 20 are designed from the same material, usually using air-oxidation-resistant conductors or semiconductor materials, so all external electrodes 20 have the same resistance. The diameter of the outer electrode 20 needs to be designed to be an appropriate value, which should not be too large or too small. If the diameter of the outer electrode 20 is designed to be too large, the effect of reducing the heat power consumption of the discharge cannot be achieved. If the diameter of the outer electrode 20 is designed to be too small, the strength is insufficient and it is easy to break. Figure 3 As shown, d1 is used to represent the diameter of the outer electrode 20. In design, 0.001mm≤d1≤9mm, that is, the diameter of each outer electrode 20 is designed to be in the range of 0.001mm~9mm, the maximum diameter of the outer electrode 20 can be designed to be 9mm, and the minimum diameter can be designed to be 0.001mm. The diameter d1 of the outer electrode 20 can be specifically determined according to the actual plasma discharge requirements. In design, the value of d1 can be determined with reference to the outer electrode diameter of the traditional electrode. Assuming that the outer electrode diameter of the traditional electrode is designed to be L, the resistance is R1, and the total number of the outer electrodes 20 is designed to be n (n≥2), and the resistance is R2, then the diameter d1 of each outer electrode 20 can be designed to be L / n, 0.001mm≤L / n≤9mm, it can be concluded that the resistance R2 of each outer electrode 20 is R11 / n, that is, the resistance of each outer electrode 20 The resistance of the outer electrode 20 is 1 / n of that of the traditional electrode. After actual experimental measurement, under the condition of not affecting the plasma discharge area and plasma density, compared with the traditional electrode, the electrode of this embodiment has a relatively reduced resistance of the outer electrode 20, and the heat loss of discharge per unit discharge area is reduced. Under the same discharge brightness, the surface temperature of the traditional electrode is 80 degrees, while the surface temperature of the electrode of this embodiment can be reduced to 60 degrees, which is 20 degrees lower than that of the traditional electrode. Therefore, multiple outer electrodes 20 with equal diameter, length and spiral pitch are connected in parallel and spirally wound on the outside of the inner electrode 10, and the diameter of the outer electrode 20 is set to an appropriate value, which can effectively reduce the heat loss in the electrode discharge process, thereby reducing the power consumption of the power supply, reducing useless work, and requiring low power for discharge. The cost of components required for the power supply will also be reduced, thereby reducing the cost of the power supply.

[0030] The electrode for plasma discharge of this embodiment has multiple outer electrodes spirally wound around the outside of the inner electrode, the ends of all the outer electrodes are connected, the diameters, lengths and spiral pitches of all the outer electrodes are designed to be the same, and the diameter of the outer electrode is designed to be in the range of 0.001mm to 0.9mm, so that the resistance of a single outer electrode is at an appropriate value, which can greatly reduce the heat loss during the electrode discharge process.

[0031] In one embodiment, referring to 1 to Figure 4 , the outer side of the inner electrode 10 is wrapped with an insulating layer 30, and the outer electrode 20 is spirally wound on the surface of the insulating layer 30, wherein the thickness of the insulating layer 30 is L1, wherein 0.001mm≤L1≤80mm. In a specific implementation, an insulating layer 30 is wrapped on the outer side of the inner electrode 10, and the outer electrode 20 is spirally wound on the surface of the insulating layer 30, and the insulating layer 30 is located between the inner electrode 10 and the outer electrode 20 as a whole, and the insulating layer 30 separates the inner electrode 10 from the outer electrode 20 to ensure that the outer electrode 20 and the inner electrode 10 are not in direct contact, and the overall thickness of the insulating layer 30 is uniform, and the insulating layer 30 is designed with inorganic or organic insulating materials, and the insulating layer 30 has the characteristics of resistance to breakdown, resistance to discharge oxidation, and resistance to high temperature. The overall thickness of the insulating layer 30 is uniform, such as Figure 4 As shown, L1 represents the thickness of the insulating layer 30. In design, 0.001 mm ≤ L1 ≤ 80 mm, that is, the thickness of the insulating layer 30 can be designed within the range of 0.001 mm to 80 mm. Of course, the thickness design of the insulating layer 30 is also related to the diameter of the inner electrode 10. The thickness of the insulating layer 30 can be specifically selected within the range of 0.001 mm to 80 mm according to the diameter of the inner electrode 10. Generally, the larger the diameter of the inner electrode 10, the larger the thickness of the insulating layer 30 is designed. By optimizing the thickness design of the insulating layer 30, the direction of the electric lines during electrode discharge can be optimized, the electric field distribution between the inner and outer electrodes 20 can be improved, especially the electric field strength at the cathode tip, thereby reducing the breakdown voltage and generating high-density plasma.

[0032] Furthermore, the outer diameter of the insulating layer 30 is 2 mm. In a specific implementation, the outer diameter of the insulating layer 30 is mainly determined by the diameter of the inner electrode 10 and the thickness of the insulating layer 30. The outer diameter of the insulating layer 30 is equal to the sum of the diameter of the inner electrode 10 and the thickness of the insulating layer 30. In this embodiment, the outer diameter of the insulating layer 30 is designed to be 2 mm. Therefore, the diameter of the inner electrode 10 is designed to be less than 2 mm. For example, when the thickness of the insulating layer 30 is 0.5 mm, the diameter of the inner electrode 10 can be designed to be 1.0 mm based on the outer diameter of the insulating layer 30 of 2 mm. For another example, when the thickness of the insulating layer 30 is 0.2 mm, the diameter of the inner electrode 10 can be designed to be 1.6 mm based on the outer diameter of 2 mm. By designing the outer diameter of the insulating layer 30 to be 2 mm, the diameter of the inner electrode 10 is limited to a range of less than 2 mm, thereby optimizing the discharge capacity of the electrode.

[0033] In one embodiment, the insulating layer 30 is a ceramic material, and the length of the insulating layer 30 in the axial direction of the inner electrode 10 is L2, where L2=0.5mm. In a specific implementation, the insulating layer 30 is designed with a ceramic material, which has a high breakdown resistance, excellent resistance to discharge oxidation, and high temperature resistance, and is a relatively ideal insulating material. When designing, the insulating layer 30 is based on being able to completely cover the radial surface of the inner electrode 10, and the outer electrode 20 is only wound around the area covered by the insulating layer 30 on the surface of the inner electrode 10, and the two threads of the outer electrode 20 that are farthest apart are both in the area covered by the insulating layer 30. The length of the insulating layer 30 in the axial direction of the inner electrode 10 affects the balance between the electric field strength, plasma density and stability during electrode discharge. L2 represents the length of the insulating layer 30 in the axial direction of the inner electrode 10. In design, L2=0.5mm, that is, the length of the insulating layer 30 in the axial direction of the inner electrode 10 is designed to be 0.5mm. The insulating layer 30 is designed to be a ceramic tube structure with a length of 0.5mm, which is sleeved on the outside of the inner electrode 10. After actual measurement, the 0.5mm ceramic tube insulating layer 30 has better breakdown characteristics and can improve the plasma generation efficiency.

[0034] In one embodiment, referring to Figure 3, the diameter of the inner electrode 10 is d2, wherein 0.001mm≤d2≤100mm. In a specific implementation, the inner electrode 10 is a cylindrical structure. In plasma discharge applications, the inner electrode 10 is usually used as an anode and the outer electrode 20 is used as a cathode. The diameter of the inner electrode 10 will affect the stability and heat dissipation of the plasma. If the diameter of the inner electrode 10 is too small, it may cause the current density to be too high, increase local heat, and may cause material loss or thermal stress problems. If the diameter of the inner electrode 10 is too large, it may reduce the electric field strength and affect the formation efficiency of the plasma. Therefore, the appropriate diameter design of the inner electrode 10 needs to balance the current density and the electric field distribution. The appropriate diameter of the inner electrode 10, in conjunction with the cooling system, can effectively disperse heat and avoid the formation of hot spots. At the same time, it can reduce energy loss and maintain efficient conversion of electrical energy into plasma kinetic energy. The diameter of the inner electrode 10 is represented by d2. In design, 0.001mm≤d2≤100mm, that is, the diameter of the inner electrode 10 is designed to be within the range of 0.001mm to 100mm. In practical applications, the optimal diameter can be determined based on the matching with the outer electrode 20. When the diameter of the outer electrode 20 is designed to be larger, the diameter of the inner electrode 10 should also be designed to be larger. Through actual measurement, the diameter of the inner electrode 10 is designed to be within the range of 0.001mm to 100mm, and the stability and heat dissipation of the plasma are at a relatively good level, which improves the efficiency and stability of the plasma generator, significantly prolongs the life of the anode, and reduces energy consumption and maintenance costs.

[0035] Furthermore, the inner electrode 10 is a nickel-plated metal wire, d2=1mm. In a specific implementation, the inner electrode 10 is designed with a nickel-plated metal wire, and its diameter is designed to be 1mm. When the inner electrode 10 is manufactured, a thin layer of metal nickel plating is deposited on the surface of the iron wire or other metal wire through an electroplating process. The diameter of the entire inner electrode 10 formed after nickel plating is 1mm. The nickel plating layer has high conductivity, which can ensure that the current is evenly distributed on the surface of the inner electrode 10, reducing the energy loss caused by excessive local resistance. At the same time, the nickel plating layer can effectively resist the erosion of the atmosphere, alkali and certain acids, and can also withstand high temperatures. By designing the inner electrode 10 as a 1mm nickel-plated metal wire, the inner electrode 10 has good corrosion resistance, mechanical strength and conductivity, and effectively balances mechanical strength and flexibility to avoid breakage caused by stress concentration.

[0036] In one embodiment, referring to Figure 1 and Figure 2, all the outer electrodes 20 are evenly spaced in the axial direction of the inner electrode 10. In a specific implementation, all the outer electrodes 20 are spirally wound around the outer side of the inner electrode 10, all the outer electrodes 20 are evenly spaced in the axial direction of the inner electrode 10, all the outer electrodes 20 are wound around the outer side of the inner electrode 10 in a non-contact state, and a suitable interval is left between two adjacent outer electrodes 20. The specific interval distance can be determined according to actual needs and is not limited here. By designing all the outer electrodes 20 to be equally spaced, a uniform electric field distribution can be formed between the outer electrodes 20, avoiding the phenomenon of excessive or low local electric field strength, thereby improving the stability and controllability of the discharge. At the same time, the equal spacing of all the outer electrodes 20 can limit the diffusion of energy in the surrounding medium and reduce local overheating or thermal damage caused by uneven energy distribution.

[0037] Further, refer to Figure 1 and Figure 6 , the outer electrodes 20 are provided with three, and the distance between two adjacent outer electrodes 20 in the axial direction of the inner electrode 10 is 1.5mm. In the specific implementation, the number of the outer electrodes 20 is designed to be three, and the three outer electrodes 20 are spirally wound on the outside of the inner electrode 10. The diameters, lengths and spiral pitches of the three outer electrodes 20 are equal, and their ends are welded together. The three outer electrodes 20 are arranged at equal intervals in the axial direction of the inner electrode 10, and the distance between two adjacent outer electrodes 20 in the axial direction of the inner electrode 10 is designed to be 1.5mm, that is, a gap of 1.5mm is left between two adjacent outer electrodes 20. After actual measurement, the outer electrode 20 spacing of 1.5mm is designed, and the current density and charge concentration are at a higher level during the electrode discharge process, the local discharge efficiency is higher, and the plasma uniformity is also better.

[0038] In one embodiment, referring to Figure 1 and Figure 2, the spiral pitch of each of the outer electrodes 20 is s, where 0.04mm≤s≤40mm. In a specific implementation, the outer electrode 20 is spirally wound around the outer side of the inner electrode 10 as a whole, and the spiral pitch of all the outer electrodes 20 is the same. The spiral pitch refers to the distance between two adjacent threads on each outer electrode 20. The size of the spiral pitch determines the winding length of the outer electrode 20. The outer electrode 20 is wound around the outer side of the inner electrode 10 for partial discharge. The larger the spiral pitch of the outer electrode 20, the shorter the length of the part wound around the outer side of the inner electrode 10, and the smaller the effective discharge area. The smaller the spiral pitch of the outer electrode 20, the longer the length of the part wound around the outer side of the inner electrode 10. Although the effective discharge area is large, the overall resistance of each outer electrode 20 is also greater, so that the heat loss during discharge is also higher. And if the pitch of the outer electrode 20 is too small, there is no discharge between two adjacent threads of each outer electrode 20, and uniform diffuse discharge cannot be achieved. In actual design, the outer electrode 20 can simulate the most suitable pitch parameters according to the diameter of the inner electrode 10, the thickness of the insulating layer 30 and the diameter of the outer electrode 20. s represents the spiral pitch of each outer electrode 20. In design, 0.04mm≤s≤40mm, that is, the spiral pitch of each outer electrode 20 is designed to be in the range of 0.04mm to 40mm, the minimum can be designed to be 0.04mm, and the maximum can be designed to be 40mm. The spiral pitch of the outer electrode 20 is designed to be 0.04mm, which is suitable for the case where the diameter of the outer electrode 20 is small or the number is small, and the design of 40mm is suitable for the case where the diameter of the outer electrode 20 is large or the number is large. After actual measurement, by designing the spiral pitch of the outer electrode 20 in the range of 0.04mm to 40mm, the discharge efficiency can be effectively improved under the condition of low heat loss.

[0039] In one embodiment, referring to Figure 1 and Figure 2, the distance between the threads of two adjacent outer electrodes 20 in the axial direction of the inner electrode 10 is s1, where 0.05mm≤s1≤10mm. In a specific implementation, multiple outer electrodes 20 are spirally wound around the outer side of the inner electrode 10 at the same time, and a certain distance is left between the threads of two adjacent outer electrodes 20 in the axial direction of the inner electrode 10, and they do not contact each other. If two adjacent outer electrodes 20 are too close or too far apart, the current density and charge concentration during discharge will be affected. Therefore, the distance between the threads of two adjacent outer electrodes 20 needs to be controlled within a reasonable range. In actual design, the distance between the threads of two adjacent outer electrodes 20 in the axial direction of the inner electrode 10 can be specifically simulated according to the spiral pitch, setting number and diameter of the outer electrode to obtain the most suitable pitch parameters. s1 represents the distance between the threads of two adjacent outer electrodes 20 in the axial direction of the inner electrode 10. In design, 0.05mm≤s1≤10mm, that is, the distance between the threads of two adjacent outer electrodes 20 in the axial direction of the inner electrode 10 is designed to be in the range of 0.05mm to 10mm, the minimum can be designed to be 0.05mm, and the maximum can be designed to be 10mm. 0.05mm is suitable for the case where the number of outer electrodes 20 is large, the spiral pitch is small, or the diameter is large, while 10mm is suitable for the case where the number of outer electrodes 20 is small, the spiral pitch is large, or the diameter is small. After actual measurement, by designing the spiral pitch of the outer electrode 20 in the range of 0.05mm to 10mm, the current density and charge concentration are at a relatively balanced level during electrode discharge, the local discharge efficiency is improved, the plasma is more uniform, and the discharge effect is more ideal.

[0040] In one embodiment, the outer electrode 20 is a tungsten wire, d1 = 0.1 mm. In a specific implementation, the outer electrode 20 is designed with a tungsten wire with a diameter of 0.1 mm. The melting point of metal tungsten is as high as 3410°C, which is much higher than other commonly used metals. It can remain stable in a high temperature environment. At the same time, metal tungsten also has the characteristics of high strength, good conductivity and strong thermal electron emission ability. The outer electrode 20 is designed as a 0.1 mm tungsten wire, which can ensure its strength while having good discharge performance and effectively reducing the heat loss of the electrode.

[0041] The embodiment of the present invention also provides an air purification device, which includes the electrode for plasma discharge described in the above embodiment. In addition, the air purification device also includes a housing, a filter, an air duct, a power supply, a negative ion generator and other components. The electrode for plasma discharge is a part of the negative ion generator, and is mainly used to generate a large number of negative ions through corona discharge, so that the negative ions adsorb particles in the air, thereby achieving the effect of purifying the air. Since the above embodiment has already made a detailed introduction to the specific structure and working principle of the electrode for plasma discharge of this embodiment, for the sake of brevity of the specification, it will not be repeated here.

[0042] The air purification device of this embodiment uses the electrode for plasma discharge provided by the embodiment of the present invention. In actual applications, the heat loss of the electrode is reduced, so it is more energy-saving and has higher overall energy efficiency than traditional air purification devices.

[0043] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An electrode for plasma discharge, characterized in that: include: Internal electrode; The outer electrode is spirally wound on the outer side of the inner electrode. There are at least two outer electrodes, and the ends of all the outer electrodes are connected. The diameter, length and spiral pitch of all the outer electrodes are equal. The diameter of the outer electrode is d1, where 0.001mm≤d1≤9mm.

2. The electrode for plasma discharge according to claim 1, characterized in that: The outer side of the inner electrode is wrapped with an insulating layer, and the outer electrode is spirally wound on the surface of the insulating layer, wherein the thickness of the insulating layer is L1, wherein 0.001 mm≤L1≤80 mm.

3. The electrode for plasma discharge according to claim 2, characterized in that: The insulating layer is made of ceramic material, and the length of the insulating layer in the axial direction of the inner electrode is L2, where L2=0.5 mm.

4. The electrode for plasma discharge according to any one of claims 1 to 3, characterized in that: The diameter of the inner electrode is d2, wherein 0.001 mm≤d2≤100 mm.

5. The electrode for plasma discharge according to claim 4, characterized in that: The inner electrode is a nickel-plated metal wire, d2=1 mm.

6. The electrode for plasma discharge according to any one of claims 1 to 3, characterized in that: All the outer electrodes are distributed at equal intervals in the axial direction of the inner electrode.

7. The electrode for plasma discharge according to any one of claims 1 to 3, characterized in that: The spiral pitch of each of the outer electrodes is s, wherein 0.04 mm≤s≤40 mm.

8. The electrode for plasma discharge according to any one of claims 1 to 3, characterized in that: The distance between the threads of two adjacent outer electrodes in the axial direction of the inner electrode is s1, wherein 0.05 mm ≤ s1 ≤ 10 mm.

9. The electrode for plasma discharge according to any one of claims 1 to 3, characterized in that: The outer electrode is a tungsten wire, d1=0.1 mm.

10. An air purification device, characterized in that: The invention comprises the electrode for plasma discharge according to any one of claims 1 to 9.

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