Air plasma generating device

Abstract

The invention is applicable to the technical field of plasma generating devices, and provides an air plasma generating device which comprises an electrode assembly, a frame assembly and a power cord, the electrode assembly comprises a metal rod electrode, the surface of the metal rod electrode is coated with a high-insulating-strength dielectric layer, and the outer side of the metal rod electrode is sleeved with a spiral electrode; the spiral electrode is of a spring type structure, and the gap between the inner diameter of the spiral electrode and the surface of the high-insulation-strength dielectric layer is smaller than 0.5 mm. The conductive end of the metal rod electrode is connected with the positive electrode of the power source through the power line, and one end of the spiral electrode is connected with the negative electrode of the power source through the power line. According to the device, the requirement for discharge voltage is low, discharge is easy to generate plasmas, due to the fact that the dielectric layer is sprayed, the environment adaptability is high, and the device can directly generate plasmas in the air regardless of high and low humidity and the like.

Description

Technical Field

[0001] This invention belongs to the technical field of plasma generating devices, and particularly relates to an air plasma generating device. Background Technology

[0002] Low-temperature plasma is a non-equilibrium plasma with an electron temperature much greater than an ion temperature. Due to its high electron density and electron energy, high concentration of active components, and gas temperature close to ambient temperature, it has been widely used in recent years in fields such as air disinfection, promoting skin wound healing, and environmental protection.

[0003] Currently, devices on the market that can directly generate low-temperature plasma using air fall into two categories: corona discharge and dielectric barrier discharge. Common dielectric barrier discharge devices are typically arranged in a cylindrical shape, such as... Figure 1 As shown, the internal and external electrodes are coaxially arranged, and are physically and electrically isolated by rigid, thick-walled insulating dielectric tubes such as quartz glass and ceramic tubes. The external electrode is tightly attached to the surface of the dielectric material. A high-voltage power supply provides a sufficiently high AC voltage to the internal and external electrodes, allowing plasma to be generated inside and outside the dielectric material. This dielectric barrier discharge air plasma generator appeared relatively early and is currently the mainstream structural form on the market. However, it has high requirements for discharge voltage. Since the gap between the internal and external electrodes is mainly determined by the wall thickness of the dielectric tube, and in order to ensure mechanical strength and insulation performance, the wall thickness of the dielectric tube is usually large (usually more than 1 mm), resulting in a large discharge gap. According to Paschen's law, the breakdown voltage is positively correlated with the product of the gap distance and the air pressure. Therefore, this structure requires a high AC voltage (usually more than 5 kV) to break down the air gap and generate plasma. This not only places high demands on the power supply but also brings greater safety hazards and energy consumption. In addition, the structure is relatively complex, and its environmental adaptability needs to be improved. Summary of the Invention

[0004] The purpose of this invention is to provide an air plasma generator that addresses the problems mentioned in the background section.

[0005] The present invention is implemented as follows: an air plasma generator includes an electrode assembly, a frame assembly, and a power line. The electrode assembly includes a metal rod electrode, the surface of which is coated with a high-insulation-strength dielectric layer. A spiral electrode is sleeved on the outer side of the metal rod electrode. The spiral electrode has a spring-type structure, and the gap between its inner diameter and the surface of the high-insulation-strength dielectric layer is less than 0.5 mm. The power lines connect the conductive end of the metal rod electrode to the positive terminal of the power supply, and one end of the spiral electrode to the negative terminal of the power supply.

[0006] Preferably, the high insulation strength dielectric layer is a ceramic dielectric layer or a Teflon dielectric layer.

[0007] Preferably, the border component includes: The end frame has a slot in it, and the two ends of the metal rod electrode are embedded in the slot. The side frame is fixedly connected to the end frame, and the end frame is filled with insulating glue.

[0008] The air plasma generator provided in this embodiment of the invention has low requirements for discharge voltage and can easily generate plasma. Due to the coating of a dielectric layer and the potting of adhesive inside the end frame, it has strong environmental adaptability. Regardless of high or low humidity, the device can directly generate plasma in the air. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a dielectric barrier discharge air plasma generator in the prior art; Figure 2 This is a schematic diagram of the structure of an air plasma generator provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the middle frame of an air plasma generator provided in an embodiment of the present invention; Figure 4 A physical diagram of an air plasma generator provided in an embodiment of the present invention; Figure 5 This is a physical diagram of the middle electrode assembly of an air plasma generator provided in an embodiment of the present invention.

[0010] In the attached diagram: 1. Electrode assembly; 2. Frame assembly; 3. Power cord; 11. Metal rod electrode; 12. Spiral electrode; 21. End frame; 22. Side frame; 23. Insulating adhesive; 24. Slot. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0012] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0013] like Figures 2 to 3The diagram shown is a structural diagram of an air plasma generator according to an embodiment of the present invention, including an electrode assembly 1, a frame assembly 2 and a power line 3. The electrode assembly 1 includes a metal rod electrode 11, the surface of which is coated with a high-insulation-strength dielectric layer, and a spiral electrode 12 is sleeved on the outside of the metal rod electrode 11. The power line 3 connects the conductive end of the metal rod electrode 11 to the positive terminal of the power supply, and connects one end of the spiral electrode 12 to the negative terminal of the power supply.

[0014] In one embodiment of the present invention, the air plasma generator addresses the problems raised in the prior art by creatively improving the electrode assembly 1, which is composed of a metal rod electrode 11 and a spiral electrode 12. The surface of the metal rod electrode 11 is coated with a dielectric layer of ceramic, Teflon, or other materials with high insulation strength, and the thickness of the dielectric layer is within the range of 0.2-0.5 mm. The spiral electrode 12 is preferably a standard spring with a wire diameter of 0.5 mm or less, and the inner diameter must ensure that the gap between the spiral electrode 12 and the surface of the dielectric layer is less than 0.5 mm. Although the structure of the metal rod electrode 11 with a dielectric layer sprayed on its surface and then fitted with a spiral electrode 12 differs from existing structures on the market, it still belongs to the dielectric barrier discharge method. By spraying an ultra-thin dielectric layer on the metal rod electrode 11 and combining it with the spiral electrode 12, a precise and uniform discharge gap of sub-millimeter level (<0.5mm) is created. According to Paschen's law, this extremely small gap causes a significant decrease in the breakdown voltage of air, resulting in low requirements for discharge voltage and easy discharge to generate plasma. In addition, due to the dielectric layer spraying, it has strong environmental adaptability. Regardless of high or low humidity, this device can directly generate plasma in the air. The number of electrode components 1 can be determined according to the actual situation.

[0015] The frame assembly 2 consists of an end frame 21 and a side frame 22. The two ends of the side frame 22 are fixedly connected to the end frame 21 by fasteners to form a whole. The end frame 21 has a slot 24 corresponding to the electrode assembly 1 inside. During installation, the two ends of the metal rod electrode 11 are respectively inserted into the slots 24 of the two end frames 21. The conductive ends of the metal rod electrode 11 are connected in series with the positive terminal of the power supply using the power cord 3, and the one end of the spiral electrode 12 is connected in series with the negative terminal of the power supply. Then, the two side frames 22 are connected to the two end frames 21 by screws to form a whole. After the assembly is completed, the inside of the two end caps is filled with insulating glue 23. The elastic structure of the spiral electrode 12 can absorb the stress caused by thermal expansion and contraction and mechanical vibration, avoiding the risk of dielectric layer cracking caused by stress concentration in traditional rigid structures. The filling with insulating glue 23 further strengthens the entire structure and provides additional moisture-proof and insulation protection.

[0016] The actual discharge effect of the device after being connected to a 1kHz power supply with a peak voltage of 2kV is as follows: Figure 3 and Figure 4 As shown, diffuse glow is clearly visible near the spiral electrode 12, indicating that the device can directly generate stable plasma in the air with a peak voltage of only 2KV. This voltage is much lower than the voltage required by commercial dielectric barrier discharge devices (usually >5KV). Therefore, the device provided in this embodiment of the invention has good market prospects as an air plasma source.

[0017] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An air plasma generator, comprising an electrode assembly (1), a frame assembly (2), and a power supply line (3), characterized in that, The electrode assembly (1) includes a metal rod electrode (11), the surface of which is coated with a high-insulation-strength dielectric layer, and a spiral electrode (12) is sleeved on the outside of the metal rod electrode (11); the spiral electrode (12) is a spring-type structure, and the gap between its inner diameter and the surface of the high-insulation-strength dielectric layer is less than 0.5 mm. The power line (3) connects the conductive end of the metal rod electrode (11) to the positive terminal of the power supply and connects one end of the spiral electrode (12) to the negative terminal of the power supply.

2. The air plasma generator according to claim 1, characterized in that, The high insulation strength dielectric layer is a ceramic dielectric layer or a Teflon dielectric layer.

3. The air plasma generator according to claim 1, characterized in that, The border component (2) includes: End frame (21), the end frame (21) is provided with a slot (24), and the two ends of the metal rod electrode (11) are embedded in the slot (24); The side frame (22) is fixedly connected to the end frame (21), and the end frame (21) is filled with insulating glue (23).

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