A multi-stage large-area low-temperature plasma jet generating device

Abstract

The present invention relates to a multi-stage large-area low-temperature plasma jet generating device, comprising a nozzle outer cover and a base. The nozzle outer cover is connected to the base to form an airflow focusing chamber and an airflow dispersion chamber structure. The airflow dispersion chamber comprises a first-stage airflow dispersion chamber and a second-stage airflow dispersion chamber. The airflow focusing chamber comprises a first-stage airflow focusing chamber, a second-stage airflow focusing chamber, and a third-stage airflow focusing chamber. A first through hole is provided at one end of the base, and a second through hole and a third through hole with different diameters are provided at the other end of the base. A first-stage airflow dispersion chamber structure is formed in the space between the two ends of the base. A second-stage airflow dispersion chamber structure is formed between one end of the base and the nozzle outer cover. A fourth through hole is provided on the upper part of the nozzle outer cover. The second through hole, the third through hole, and the fourth through hole respectively form the first-stage airflow focusing chamber, the second-stage airflow focusing chamber, and the third-stage airflow focusing chamber structure. The distance between plasma jets can be reduced to generate large-area uniformly dispersed low-temperature plasma.

Description

Technical Field

[0001] The present invention relates to the field of electrical engineering and electrical technology, and in particular to a multi-stage large-area low-temperature plasma jet generating device. Background Art

[0002] Atmospheric pressure low-temperature plasma jets have broad application prospects, but plasma jets are often thin and narrow cylindrical. Considering the actual supply capacity of the reaction gas flow, the diameter of a single jet is difficult to meet the application scenarios that require large-area low-temperature plasma treatment. Jet arrays are a feasible solution to the above problems, but traditional jet arrays require multiple arrays in parallel, which increases the number of electrodes, makes the array structure more complex, and the distance between jets is large. The plasma uniformity of the jet array is poor. Further optimizing the low-temperature plasma jet array structure and improving the uniformity of the plasma jet array are issues that urgently need to be studied in this application field. Summary of the Invention

[0003] Based on the above description, the present invention provides a multi-stage large-area low-temperature plasma jet generating device for reducing the distance between plasma jets in an array and generating large-area uniformly dispersed low-temperature plasma.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: A multi-stage large-area low-temperature plasma jet generating device, comprising: a nozzle outer cover and a base, the nozzle outer cover is connected to the base to form an airflow focusing chamber and an airflow dispersion chamber structure, the airflow dispersion chamber comprises a first-stage airflow dispersion chamber and a second-stage airflow dispersion chamber, the airflow focusing chamber comprises a first-stage airflow focusing chamber, a second-stage airflow focusing chamber, and a third-stage airflow focusing chamber, the base is a hollow structure, one end of the base is provided with a first through hole, the other end of the base is provided with a second through hole and a third through hole of different diameters, the space between the two ends of the base forms the first-stage airflow dispersion chamber structure, the second-stage airflow dispersion chamber structure is formed between one end of the base and the nozzle outer cover, the upper part of the nozzle outer cover is provided with a fourth through hole, the second through hole, the third through hole, and the fourth through hole respectively form the first-stage airflow focusing chamber, the second-stage airflow focusing chamber, and the third-stage airflow focusing chamber structure.

[0005] On the basis of the above technical solution, the present invention can also be improved as follows.

[0006] Furthermore, the first through hole includes multiple first cavities for inserting external high-voltage electrodes, and second cavities for inputting reaction gas. The second cavities are arranged in the middle of the multiple first cavities, and the multiple first cavities are arranged radially in a circular shape. The reaction gas can be evenly transported to the first-stage airflow focusing cavity through the second cavity.

[0007] Furthermore, a conical smooth transition structure is provided at the connection between the first-stage airflow focusing cavity and the first-stage airflow dispersion cavity, and the high-voltage electrode discharge end is provided at the smooth transition structure of the first-stage airflow focusing cavity to excite a plasma jet in the reaction gas.

[0008] Furthermore, the first-stage airflow bundling chamber and the second-stage airflow bundling chamber are arranged in communication with each other, and the inner diameter of the first-stage airflow bundling chamber is smaller than the inner diameter of the second-stage airflow bundling chamber. The second-stage airflow bundling chamber is used to slow down the plasma jet, and the first-stage airflow bundling chamber and the second-stage airflow bundling chamber are aligned with the center of the first cavity.

[0009] Furthermore, the base is a cylindrical structure, the inner wall of the first cavity is provided with an internal thread structure, the internal thread structure fits with the external thread structure of the high-voltage electrode, and the inner diameter of the second cavity is larger than the inner diameter of the first cavity.

[0010] Furthermore, the base includes a first end and a second end, the diameter of the first end is smaller than the diameter of the second end, the first end is sealed to the nozzle outer cover, and the outer diameter of the nozzle outer cover is the same as the diameter of the second end.

[0011] Furthermore, the nozzle outer cover as a whole is a "convex" cylindrical cover structure, the exterior of the nozzle outer cover is a streamlined and smooth structure, the interior of the nozzle outer cover is a hollow structure, the first end and the nozzle outer cover form a second-stage airflow dispersion chamber structure, and the plasma jet is evenly dispersed in the second-stage airflow dispersion chamber through the second-stage airflow focusing chamber.

[0012] Furthermore, the depth of the first-stage airflow focusing cavity is the same as the depth of the second-stage airflow focusing cavity, and the depths of the first-stage airflow focusing cavity and the second-stage airflow focusing cavity are greater than the depth of the second-stage airflow dispersion cavity.

[0013] Furthermore, the inner diameter of the first-stage airflow focusing cavity is larger than the inner diameter of the third-stage airflow focusing cavity.

[0014] Furthermore, there are multiple third-level airflow bundling cavities, and the number of the third-level airflow bundling cavities is greater than the number of the first-level airflow bundling cavities and the second-level airflow bundling cavities. The third-level airflow bundling cavities are evenly arranged, and the third-level airflow bundling cavities are arranged in a circular ring structure with multiple rows radiating outward.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0016] 1. The generating device is provided with multiple reaction chambers of different diameters, including a first-stage airflow dispersion chamber, a first-stage airflow focusing chamber, a second-stage airflow focusing chamber, a second-stage airflow dispersion chamber, and a third-stage airflow focusing chamber; each stage of the focusing chamber array is used to generate a plasma jet array, and each stage of the airflow dispersion chamber is used to uniformly generate the background gas of the plasma, thereby further uniformizing the plasma jet.

[0017] 2. The generator adopts a multi-stage reaction chamber structure, which increases the number of jet arrays, reduces the number of electrode arrays, and eliminates the correspondence between electrode arrays and jet arrays; the jet array is determined by the number of the last-stage airflow beam cavity array, which is conducive to the generation of a more uniform large-area plasma jet array. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a multi-stage large-area low-temperature plasma jet generating device from a first perspective provided by an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the top structure of a multi-stage large-area low-temperature plasma jet generating device provided by an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of the bottom structure of a multi-stage large-area low-temperature plasma jet generating device provided by an embodiment of the present invention;

[0021] Figure 4 A schematic structural diagram from a second perspective of a multi-stage, large-area, low-temperature plasma jet generating device provided by an embodiment of the present invention;

[0022] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure along the middle line AA;

[0023] Figure 6 Schematic diagram of the structure of the nozzle cover in an embodiment of the present invention;

[0024] Figure 7 for Figure 6 Schematic diagram of the cross-sectional structure along the middle edge BB;

[0025] Figure 8 This is a schematic structural diagram of a base in an embodiment of the present invention;

[0026] Figure 9 for Figure 8 Schematic diagram of the cross-sectional structure of the middle edge CC;

[0027] Figure 10 This is a schematic structural diagram of a multi-stage large-area low-temperature plasma jet generating device in use according to an embodiment of the present invention;

[0028] Figure 11 Schematic diagram of the working effect of a multi-stage large-area low-temperature plasma jet generating device in an embodiment of the present invention;

[0029] Figure 12 Schematic diagram of the working principle of a multi-stage large-area low-temperature plasma jet generating device according to an embodiment of the present invention;

[0030] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0031] 1. Nozzle cover; 2. Base; 21. Airflow focusing chamber; 211. First-stage airflow focusing chamber; 212. Second-stage airflow focusing chamber; 213. Third-stage airflow focusing chamber; 22. Airflow dispersion chamber; 221. First-stage airflow dispersion chamber; 222. Second-stage airflow dispersion chamber; 23. First through hole; 231. First cavity; 232. Second cavity; 24. First end; 25. Second end; 3. High-voltage electrode; 4. Reaction gas; 5. High-voltage power supply; 6. Grounding current-limiting resistor; 7. Current-limiting resistor; 8. Reaction gas device; 9. Gas valve switch. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0034] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", "around", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the engineering construction referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] See also Figure 1-12 , this embodiment provides a multi-stage large-area low-temperature plasma jet generating device, comprising: a nozzle outer cover 1, a base 2;

[0036] The nozzle outer cover 1 is connected to the base 2 to form an airflow focusing chamber 21 and an airflow dispersion chamber 22 structure. The airflow dispersion chamber 22 includes a first-level airflow dispersion chamber 221 and a second-level airflow dispersion chamber 222. The airflow focusing chamber 21 includes a first-level airflow focusing chamber 211, a second-level airflow focusing chamber 212, and a third-level airflow focusing chamber 213. The base 2 is a hollow structure. A first through hole 23 is provided at one end of the base 2, and a second through hole and a third through hole of different diameters are provided at the other end of the base 2. The space between the two ends of the base 2 forms the first-level airflow dispersion chamber 221 structure, and the second-level airflow dispersion chamber 222 structure is formed between one end of the base 2 and the nozzle outer cover 1. A fourth through hole is provided on the upper part of the nozzle outer cover 1. The second through hole, the third through hole, and the fourth through hole respectively form the first-level airflow focusing chamber 211, the second-level airflow focusing chamber 212, and the third-level airflow focusing chamber 213 structures. It should be noted that the first-level airflow bunching cavity 211, the second-level airflow bunching cavity 212, and the third-level airflow bunching cavity 213 structures mentioned here refer to a cavity structure formed by the holes of the second through hole, the third through hole, and the fourth through hole respectively; and the first-level airflow bunching cavity 211, the second-level airflow bunching cavity 212, and the third-level airflow bunching cavity 213 structures can all produce plasma jet arrays, and the first-level airflow dispersion cavity 221 and the second-level airflow dispersion cavity 222 structures can all even out the background gas generated by the plasma and further even out the plasma jet. The airflow bunching cavity mentioned here includes the first-level airflow bunching cavity 211, the second-level airflow bunching cavity 212, the third-level airflow bunching cavity 213, the first-level airflow dispersion cavity 221, and the second-level airflow dispersion cavity 222, that is, multiple levels can be set, not limited to the three-level airflow bunching cavity 21 and the two-level airflow dispersion cavity 22 here, and can be set according to needs.

[0037] In this embodiment, the first through hole 23 includes a plurality of first cavities 231 for inserting the external high-voltage electrode 3, and a second cavity 232 for inputting the reaction gas 4. The second cavity 232 is arranged in the middle of the plurality of first cavities 231, and the plurality of first cavities 231 are arranged in a circumferential radial pattern. The reaction gas 4 can be uniformly transported to the first-stage gas flow converging cavity 211 through the second cavity 232. It should be noted that, please refer to the attached Figure 2 , Attachment Figure 6 The circumferential radial arrangement mentioned here refers to a circular ring structure in which circular holes are evenly arranged outward from the central hole. One or more circular ring structures can be arranged outward from the center.

[0038] For preference, please see the attached Figure 5 , Attachment Figure 9A conical smooth transition structure is provided at the connection between the first-stage airflow focusing chamber 211 and the first-stage airflow dispersion chamber 221. The discharge end of the high-voltage electrode 3 is disposed at the smooth transition structure of the first-stage airflow focusing chamber 211 to stimulate a plasma jet in the reaction gas 4. In other words, the high-voltage electrode 3 can discharge into either the first-stage airflow dispersion chamber 221 or the first-stage airflow focusing chamber 211, and the height of the first-stage airflow dispersion chamber 221 is determined by the size of the high-voltage electrode 3. The conical smooth transition structure facilitates the uniform dispersion of the reaction gas 4 in the first-stage airflow dispersion chamber 221 into the first-stage airflow focusing chamber 211. After the high-voltage electrode 3 is installed, the discharge end of the high-voltage electrode 3 just slightly enters the interior of the first-stage airflow focusing chamber 211, thereby stimulating a plasma jet in the high-speed reaction gas 4 in the first-stage airflow focusing chamber 211. The reaction gas 4 can be an inert gas, preferably helium.

[0039] Preferably, the first-stage airflow bundling cavity 211 and the second-stage airflow bundling cavity 212 are arranged in communication, and the inner diameter of the first-stage airflow bundling cavity 211 is smaller than the inner diameter of the second-stage airflow bundling cavity 212. The second-stage airflow bundling cavity 212 is used to slow down the plasma jet. The first-stage airflow bundling cavity 211 and the second-stage airflow bundling cavity 212 are aligned with the center of the first cavity 231. It should be noted that the diameter of the second-stage airflow bundling cavity 212 can be 4mm-8mm, preferably 6mm, and the depth is preferably 10mm; the diameter of the first-stage airflow bundling cavity 211 is 2-3mm, preferably 3mm, and the depth is preferably 10mm.

[0040] Please see the attached Figure 3 , Attachment Figure 8 , the base 2 is a cylindrical structure, the inner wall of the first cavity 231 is provided with an internal thread structure, the internal thread structure is fitted with the external thread structure of the high-voltage electrode 3, and the inner diameter of the second cavity 232 is larger than the inner diameter of the first cavity 231. Wherein, the base 2 is made of an insulating material with good electrical properties, preferably transparent organic glass. The first cavity 231 can be arranged in multiple rows, and preferably, the number of the first cavities 231 is 5. The thickness of the internal thread structure of the second cavity 232 is determined by the thread depth of the electrode, and the inner diameter of the second cavity 232 is 6-12mm, preferably 10mm. The specific structure of the first cavity 231 is determined by the connection method between the external air pipe and the base 2. The diameter of the first cavity 231 can be 4mm-8mm, preferably 6mm in diameter.

[0041] Please see the attached Figure 8The base 2 includes a first end 24 and a second end 25. The diameter of the first end 24 is smaller than that of the second end 25. The first end 24 is sealed to the nozzle cover 1. The outer diameter of the nozzle cover 1 is the same as the diameter of the second end 25. The base 2 and the nozzle cover 1 are preferably sealed and bonded, and a sealed hollow second-stage airflow dispersion chamber 222 is formed between the base 2 and the nozzle cover 1.

[0042] Please see the attached Figure 1 , Attachment Figure 4 The nozzle cover 1 is an overall convex cylindrical cover structure. The exterior of the nozzle cover 1 is streamlined and smooth, while the interior of the nozzle cover 1 is hollow. The first end 24 and the nozzle cover 1 form a second-stage airflow dispersion cavity 222. The plasma jet passes through the second-stage airflow focusing cavity 212 and is evenly dispersed within the second-stage airflow dispersion cavity 222. The nozzle cover 1 is made of an insulating material with good electrical properties, preferably transparent organic glass.

[0043] Preferably, the depth of the first-stage airflow focusing cavity 211 is the same as the depth of the second-stage airflow focusing cavity 212, and the depths of the first-stage airflow focusing cavity 211 and the second-stage airflow focusing cavity 212 are greater than the depth of the second-stage airflow dispersion cavity 222. The inner diameter of the first-stage airflow focusing cavity 211 is greater than the inner diameter of the third-stage airflow focusing cavity 213.

[0044] Preferably, the third-level airflow bunching cavity 213 is provided with a plurality of third-level airflow bunching cavities 213, and the number of the third-level airflow bunching cavities 213 is greater than the number of the first-level airflow bunching cavities 211 and the second-level airflow bunching cavities 212. The third-level airflow bunching cavities 213 are evenly arranged, and the third-level airflow bunching cavities 213 are provided with multiple rows of annular structures radiating outward. The annular structures of the third-level airflow bunching cavities 213 can be densely arranged, and the third-level airflow bunching cavities 213 can be provided with 2-5 rows of annular structures, preferably 2 rows, and can also be flexibly adjusted according to actual applications. The third-level airflow bunching cavity 213 is a circular through hole, and the diameter of the third-level airflow bunching cavity 213 is 1-2 mm, preferably 2 mm, and the depth of the second-level airflow dispersion cavity 222 is 3-10 mm, preferably 10 mm. By setting a multi-stage reaction chamber structure, the number of plasma jet arrays is increased, the number of electrode arrays is reduced, and the correspondence between the electrode array and the plasma jet array is cancelled. The array of the third-stage airflow focusing cavities 213 can be densely arranged to reduce the distance between the plasma jets in the array, thereby generating a large-area uniformly dispersed low-temperature plasma.

[0045] Please see the attached Figure 12During operation, the multi-stage, large-area, low-temperature plasma jet generator is connected to a grounded current-limiting resistor 6 at one end of a high-voltage power supply 5. A voltage is applied to each high-voltage electrode 3 via a current-limiting resistor 7. Reactive gas 4 from an external reactive gas device 8 enters the first chamber 231 via a gas valve switch 9. Reactive gas 4 is injected into the multi-stage airflow dispersion chamber 22 and airflow focusing chamber 21 through a reactive gas inlet. Plasma is generated at the end of the high-voltage electrode 3 within the first-stage airflow focusing chamber 211. Under the influence of the reactive gas 4, the plasma is ejected in the form of a jet array through the two-stage airflow focusing chamber 21 into the second-stage airflow dispersion chamber 222, where it is evenly dispersed and distributed. Finally, under the influence of the airflow, the plasma in the second-stage airflow dispersion chamber 222 is evenly ejected to the exterior of the device through the denser third-stage airflow focusing chamber 213, generating a relatively uniform, large-area, low-temperature plasma jet.

[0046] In summary, the generating device is provided with multiple levels of reaction chambers of different diameters, including a first-level airflow dispersion chamber 221, a first-level airflow bundling chamber 211, a second-level airflow bundling chamber 212, a second-level airflow dispersion chamber 222, and a third-level airflow bundling chamber 213; each level of airflow bundling chamber 21 array is used to generate a plasma jet array, and each level of airflow dispersion chamber 22 is used to uniformly generate the background gas of the plasma, thereby further uniformizing the plasma jet; and the generating device is provided with a multi-stage reaction chamber structure, which increases the number of jet arrays, reduces the number requirement for the electrode array, and cancels the correspondence between the electrode array and the jet array; the jet array is determined by the number of the last-level airflow bundling chamber 21 array, which is conducive to generating a more uniform large-area plasma jet array.

[0047] 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, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-stage large-area low-temperature plasma jet generating device, characterized in that: The nozzle cover comprises a nozzle outer cover and a base, wherein the nozzle outer cover is connected to the base to form an airflow focusing chamber and an airflow dispersion chamber structure, wherein the airflow dispersion chamber comprises a first-stage airflow dispersion chamber and a second-stage airflow dispersion chamber, and the airflow focusing chamber comprises a first-stage airflow focusing chamber, a second-stage airflow focusing chamber and a third-stage airflow focusing chamber. The base is a hollow structure, a first through hole is provided at one end of the base, and a second through hole and a third through hole of different diameters are provided at the other end of the base. The space between the two ends of the base forms the first-stage airflow dispersion chamber structure, and a space is formed between one end of the base and the nozzle outer cover. There is a second-stage airflow dispersion chamber structure, and a fourth through hole is provided on the upper part of the nozzle outer cover. The second through hole, the third through hole, and the fourth through hole respectively form the first-stage airflow focusing chamber, the second-stage airflow focusing chamber, and the third-stage airflow focusing chamber structure. The first through hole includes a plurality of first cavities for inserting external high-voltage electrodes, and a second cavity for inputting reaction gas. The second cavity is arranged in the middle of the plurality of first cavities, and the plurality of first cavities are arranged radially in a circular shape. The reaction gas can be evenly transported to the first-stage airflow focusing chamber through the second cavity.

2. The multi-stage large-area low-temperature plasma jet generating device according to claim 1, characterized in that: A conical smooth transition structure is provided at the connection between the first-stage airflow focusing cavity and the first-stage airflow dispersion cavity, and the high-voltage electrode discharge end is provided at the smooth transition structure of the first-stage airflow focusing cavity to excite a plasma jet in the reaction gas.

3. The multi-stage large-area low-temperature plasma jet generating device according to claim 2, characterized in that: The first-stage airflow bundling cavity and the second-stage airflow bundling cavity are arranged in communication with each other, and the inner diameter of the first-stage airflow bundling cavity is smaller than the inner diameter of the second-stage airflow bundling cavity. The second-stage airflow bundling cavity is used to slow down the plasma jet. The first-stage airflow bundling cavity and the second-stage airflow bundling cavity are aligned with the center of the first cavity.

4. The multi-stage large-area low-temperature plasma jet generating device according to claim 3, characterized in that: The base is a cylindrical structure. The inner wall of the first cavity is provided with an internal thread structure, which fits with the external thread structure of the high-voltage electrode. The inner diameter of the second cavity is larger than the inner diameter of the first cavity.

5. The multi-stage large-area low-temperature plasma jet generating device according to claim 1, characterized in that: The base includes a first end and a second end. The diameter of the first end is smaller than the diameter of the second end. The first end is sealed and connected to the nozzle outer cover. The outer diameter of the nozzle outer cover is the same as the diameter of the second end.

6. The multi-stage large-area low-temperature plasma jet generating device according to claim 5, characterized in that: The nozzle outer cover as a whole is a "convex" cylindrical cover structure, the outside of the nozzle outer cover is a streamlined and smooth structure, the inside of the nozzle outer cover is a hollow structure, the first end and the nozzle outer cover form a second-stage airflow dispersion cavity structure, and the plasma jet is evenly dispersed in the second-stage airflow dispersion cavity through the second-stage airflow focusing cavity.

7. The multi-stage large-area low-temperature plasma jet generating device according to claim 1, characterized in that: The depth of the first-stage airflow focusing cavity is the same as the depth of the second-stage airflow focusing cavity, and the depths of the first-stage airflow focusing cavity and the second-stage airflow focusing cavity are greater than the depth of the second-stage airflow dispersion cavity.

8. The multi-stage large-area low-temperature plasma jet generating device according to claim 1, characterized in that: The inner diameter of the first-stage airflow focusing cavity is larger than the inner diameter of the third-stage airflow focusing cavity.

9. The multi-stage large-area low-temperature plasma jet generating device according to claim 1, characterized in that: There are multiple third-level airflow bundling cavities, and the number of the third-level airflow bundling cavities is greater than the number of the first-level airflow bundling cavities and the second-level airflow bundling cavities. The third-level airflow bundling cavities are evenly arranged, and the third-level airflow bundling cavities are arranged in a circular ring structure with multiple rows radiating outward.

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