Low-temperature plasma generation device

Abstract

The utility model relates to the field of plasma medical technology, concretely relates to a low temperature plasma generating device, include: positive high voltage electrode, when ionizing gas, access positive high voltage electricity, negative high voltage electrode, when ionizing gas, access negative high voltage electricity, generating tube, the generating tube is provided with the plasma jet's generating cavity, is provided with the inlet of the flow gas, jet port and electrode hole with generating cavity intercommunication on the generating tube, wherein, gas enters generating cavity via the inlet of the flow gas, plasma jet emits via jet port, the discharge end of positive high voltage electrode and the discharge end of negative high voltage electrode enter generating cavity via electrode hole, based on the design of double high pressure, single electrode only needs half driving voltage to realize the discharge effect of conventional high pressure, greatly reduces the insulation voltage resistance requirement of electrode, the number of positive ion and the number of electron are roughly equal, realize the electrical neutrality of charge, do not need to rely on ground electrode neutralization charge.

Description

Technical Field

[0001] This utility model relates to the field of plasma medicine technology, specifically to a low-temperature plasma device. Background Technology

[0002] Atmospheric pressure plasma jets have demonstrated significant advantages in the field of skin treatment, with applications covering acne treatment, fading of blemishes, anti-aging, promoting wound healing, and treating specific skin diseases. Compared to traditional lasers or physical resurfacing, plasma technology does not vaporize tissue, thus preserving the separated epidermis intact as a natural dressing, reducing the risk of infection and pigmentation.

[0003] To form plasma under atmospheric pressure, it is inevitable to energize the electrodes to generate a high-voltage electric field stronger than the breakdown field of the gas medium, which in turn ionizes the gas medium to produce a plasma jet. The plasma jet needs to act on the human body. To ensure that the human body is not electrocuted after the plasma jet acts on the human body, the existing technology usually chooses to connect the human skin to the ground wire.

[0004] For example, in patent application number 202411788131, a ring-shaped metal grounding plate is provided at the end of the jet device. The high-voltage electrode corresponds to the hole in the middle of the metal grounding plate. The high-voltage electrode is used to generate the plasma jet. The metal grounding plate is connected to both human skin and a grounding wire, which can conduct the current in the hole to avoid electric shock. In patent application number 201611222414, a wristband is set as a conductive grounding electrode, and then the grounding electrode is connected to a grounding wire to conduct the plasma current generated by the high-voltage electrode, thereby avoiding electric shock.

[0005] As mentioned above, the plasma generation method commonly used in the prior art is to generate a plasma jet by energizing a high-voltage electrode, and then, with the cooperation of a ground electrode, allow the plasma jet to act on the human body and be discharged through the ground electrode, thus avoiding electric shock to the skin.

[0006] The problem with this plasma jet generation method is that the voltage applied to the high-voltage electrode is too high, and the insulation withstand voltage requirements of the high-voltage electrode are too high; the ground electrode and grounding wire that must be set up not only increase the cost of the device, but also increase the complexity of the structural design. Utility Model Content

[0007] 1. The problem to be solved To address the problems of excessively high insulation and withstand voltage requirements for high-voltage electrodes, high cost, and complex structure in existing plasma jet generation devices, this invention provides a low-temperature plasma generator that reduces the insulation and withstand voltage requirements for high-voltage electrodes, and is also low in cost and simple in structure.

[0008] 2. Technical Solution To solve the above problems, the technical solution adopted by this utility model is as follows: A low-temperature plasma generator, comprising: A positive high-voltage electrode is connected to a positive high-voltage voltage during gas ionization; The negative high-voltage electrode is connected to a negative high-voltage voltage when the gas is ionized; The generating tube contains a plasma jet generating chamber. The generating tube is equipped with an incoming gas inlet, a jet outlet, and an electrode hole that are connected to the generating chamber. Gas enters the generating chamber through the incoming gas inlet, and the plasma jet is ejected through the jet outlet. The discharge ends of the positive high-voltage electrode and the negative high-voltage electrode enter the generating chamber through the electrode hole. When the positive high voltage electrode and the negative high voltage electrode are connected to the positive high voltage and the negative high voltage respectively, the gas in the generating cavity can be ionized and a plasma jet can be generated. The voltage value of the plasma jet does not exceed the safe voltage value for the human body.

[0009] As a preferred embodiment of this utility model, the absolute values ​​of the positive high voltage and the negative high voltage connected to the positive high voltage electrode and the negative high voltage electrode are not more than 10% of the larger absolute value.

[0010] As a preferred embodiment of this utility model, the discharge ends of the positive high-voltage electrode and the negative high-voltage electrode are centrally symmetrically distributed about the central axis of the generating cavity, so as to form a uniform electric field in the generating cavity.

[0011] As a preferred embodiment of this utility model, two electrode holes are provided, and the two electrode holes are centrally symmetrically distributed about the central axis of the generating cavity.

[0012] As a preferred embodiment of this utility model, the low-temperature plasma generating device further includes: The circuit assembly is electrically connected to the positive high-voltage electrode and the negative high-voltage electrode, and provides positive high-voltage electricity and negative high-voltage electricity to the positive high-voltage electrode and the negative high-voltage electrode, respectively; The gas path assembly is connected to the incoming gas inlet on the generating tube and is used to input gas flow into the generating chamber.

[0013] As a preferred embodiment of this utility model, the circuit assembly includes: The high voltage transformer is used to provide positive and negative high voltage to the positive and negative high voltage electrodes. The high voltage transformer is also electrically connected to a switch for controlling the on and off of the circuit and a main board for controlling the voltage. There are two resistive impedance matching components. One end of each component is connected to the positive high voltage electrode and the negative high voltage electrode, respectively, and the other end is connected to the high voltage transformer.

[0014] As a preferred embodiment of this utility model, the gas path assembly includes: A gas input pipe, one end of which is connected to a gas source, is used to supply gas to the generating pipe; The endotracheal adapter connects the two ends of the endotracheal adapter to the gas input tube and the gas generation tube, respectively.

[0015] As a preferred embodiment of this utility model, the low-temperature plasma generator also includes a housing, and an installation cavity is provided inside the housing. The circuit components, gas circuit components, positive high-voltage electrode, negative high-voltage electrode and generator tube are all fixedly installed in the installation cavity.

[0016] As a preferred embodiment of the present invention, the outer shell includes an upper shell and a lower shell, which are configured to be detachably connected.

[0017] As a preferred embodiment of this utility model, the outer shell is configured as a hand tool shell, and openings are respectively provided at both ends of the hand tool shell in the length direction. The generating tube is located in the opening at one end, and the gas input tube enters the hand tool shell through the opening at the other end.

[0018] As a preferred embodiment of this utility model, the outer shell also includes a front cover, which is fitted over the opening at one end where the generating tube is located, and can seal the seam between the upper shell and the lower shell to construct a seamless circumferential jet channel.

[0019] 3. Beneficial effects Compared with the prior art, the beneficial effects of this utility model are as follows: (1) By setting positive high voltage electrode and negative high voltage electrode, positive high voltage and negative high voltage are respectively applied, and a single electrode only needs half of the driving voltage to achieve the discharge effect of conventional high voltage, which greatly reduces the insulation and withstand voltage requirements of the electrode.

[0020] (2) This utility model provides symmetrical charge compensation through the positive high voltage electrode and the negative high voltage electrode themselves, forming a stable positive and negative ion pair distribution between the positive high voltage electrode and the negative high voltage electrode. The number of positive ions is approximately equal to the number of electrons, realizing the neutralization of charge. It does not rely on the ground electrode to neutralize the charge. The structure is simple and the cost is low. Furthermore, air can be used as the ionization gas, further reducing the cost. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of plasma jet generation by a single high-voltage electrode in the prior art, wherein Figure A is a front view and Figure B is a cross-sectional view of Figure A along the BB direction. Figure 2 This is a schematic diagram of plasma jets generated by two high-voltage electrodes, where Figure A is a front view and Figure B is a cross-sectional view of Figure A along the AA direction. Figure 3 This is a schematic diagram of an explosion of a low-temperature plasma generator; Figure 4 This is a schematic diagram of the lower housing and the components installed therein; Figure 5 This is a schematic diagram of the circuit components and two high-voltage electrodes; Figure 6 This is a schematic diagram of the gas path components and generating pipe; Figure 7 A schematic diagram of an explosion of the hand tool's outer casing; Figure 8 Figure A is a schematic diagram of the front cover, where Figure A is the front view, Figure B is a cross-sectional view of Figure A along the AA direction, and Figure C is a cross-sectional view of Figure A along the BB direction. Figure 9 Figure A is a schematic diagram of the upper shell structure, where Figure B is a front view, Figure B is a top view, and Figure C is a right view. Figure 10 Figure A is a schematic diagram of the lower shell structure, where Figure A is a front view, Figure B is a bottom view, and Figure C is a right view. Figure 11 The voltage waveform at the end closest to the positive high-voltage electrode when argon gas is ionized by dual high-voltage electrodes. Figure 12 The voltage waveform at the end near the negative high-voltage electrode when argon gas is ionized by dual high-voltage electrodes. Figure 13 Voltage waveform near the jet center when argon gas is ionized by dual high-voltage electrodes; Figure 14 The voltage waveform at the end closest to the positive high-voltage electrode when air is ionized by dual high-voltage electrodes; Figure 15 The voltage waveform at the end closest to the negative high-voltage electrode when air is ionized by dual high-voltage electrodes; Figure 16 The voltage waveform near the center of the jet when air is ionized by dual high-voltage electrodes; Figure 17 The voltage waveform at the end near the high-voltage electrode when air is ionized by a single high-voltage electrode; Figure 18 The voltage waveform near the center of the jet when a single high-voltage electrode ionizes air; Figure 19 The voltage waveform at the end near the high-voltage electrode when argon gas is ionized by a single high-voltage electrode. Figure 20 The voltage waveform near the center of the jet when argon gas is ionized by a single high-voltage electrode.

[0022] Explanation of the labels in the diagram: 100. A low-temperature plasma generator; 110. Positive high voltage electrode; 120. Negative high-voltage electrode; 130. Generating tube; 131. Generating chamber; 132. Incoming gas inlet; 133. Jet nozzle; 134. Electrode hole; 140. Circuit components; 141. High voltage transformer; 142. Switch; 143. Main board; 144. Resistive impedance matching components; 150. Gas circuit assembly; 151. Gas inlet pipe; 152. Gas pipe adapter; 153. Gas source; 160. Outer shell; 161. Mounting cavity; 162. Upper shell; 163. Lower shell; 164. Front cover; 164-1. Bayonet; 164-2. Locking block; 165. Anti-slip part; 166. Heat dissipation hole; 200. Plasma jet. Detailed Implementation

[0023] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0024] The structures, proportions, and sizes illustrated in the accompanying drawings are solely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0025] The commonly used plasma generation method in the existing technology is as follows: energize the high-voltage electrode to generate a high-voltage electric field that is greater than the breakdown field strength of the gas medium, thereby ionizing the gas medium to generate plasma. Then, with the cooperation of the ground electrode, the plasma jet 200 acts on the human body and is discharged through the ground electrode to avoid electric shock to the skin.

[0026] The above-mentioned plasma generation methods have the following problems: (1) The generation of high voltage electric field depends on only one high voltage electrode. The voltage applied to a single high voltage electrode is too large. For example, if the voltage required to ionize gas is 10kV, then the voltage of the high voltage electrode needs to reach 10kV, which puts too high a requirement on the insulation withstand voltage of the high voltage electrode. (2) When using a single high voltage, the jet region is located in the region between high voltage and zero potential. The plasma is conductive. When the jet treatment comes into contact with the human body, the human body is equivalent to being in a high voltage electric field. The plasma also carries a high voltage. Therefore, it relies on the ground electrode to neutralize the charge. The ground electrode and grounding wire that must be set not only increase the cost of the device, but also increase the complexity of the structural design. At the same time, the ground electrode and grounding wire also limit the application scenarios of the device, that is, it must be plugged into a power socket to be used.

[0027] To solve the above problems, such as Figures 1-20 As shown, this embodiment provides a low-temperature plasma generator, including a positive high-voltage electrode 110, a negative high-voltage electrode 120, and a generator tube 130. A plasma jet generation chamber 131 is provided inside the generator tube 130. The generator tube 130 is provided with an incoming gas inlet 132, a jet outlet 133, and an electrode hole 134 communicating with the generator chamber 131. The gas required for ionization enters the generator chamber 131 through the incoming gas inlet 132, and the plasma jet 200 generated by ionization exits through the jet outlet 133. The discharge ends of both the positive high-voltage electrode 110 and the negative high-voltage electrode 120 enter the generator chamber 131 through the electrode hole 134. During operation, the positive high-voltage electrode 110 and the negative high-voltage electrode 120 are connected to positive and negative high voltages respectively. The generated high-voltage electric field can ionize the gas in the generator chamber 131 and generate the plasma jet 200. The voltage value of the plasma jet 200 does not exceed the safe voltage value for the human body.

[0028] The principle of plasma generation by dual high-voltage ionization of gas in this invention is as follows: The dual high-voltage design creates an asymmetric strong electric field between the electrodes, with an electric field strength reaching tens of thousands of volts / cm, far exceeding the gas breakdown threshold (approximately 3 kV / mm for air). When the electric field strength exceeds the breakdown field strength of the gas medium, electrons in gas molecules (such as oxygen and nitrogen) are accelerated, gaining sufficient energy to collide with neutral molecules, leading to molecular ionization and the generation of electron-ion pairs. This process forms the initial plasma seed, laying the foundation for subsequent chain reactions. Electrons generated by the initial ionization in the dual high-voltage system continue to accelerate in the electric field, colliding with more neutral molecules and triggering secondary ionization, forming an exponentially increasing "avalanche effect" in the number of electrons; for example, a single electron may generate 10 electrons through collisions. 3 -10 6 New electrons rapidly expand the plasma region. During ionization, electrons attach to neutral molecules to form negative ions (such as O2). - ), and molecules that lose electrons become positive ions (such as N2). + The strong electric field generated by the dual high voltages drives electrons and ions to move at high speeds, significantly increasing the collision frequency and achieving a plasma density of up to 10⁻⁶ per unit volume. 14 -10 16 Particles / m 3This high-density plasma contains high-energy electrons, ions, and free radicals (such as -OH, -O2). - These active particles possess strong oxidizing and reactive properties.

[0029] Compared with existing technologies, this utility model adopts a dual high-voltage design, which has the following outstanding advantages: This utility model innovatively adopts a dual high-voltage electrode design, with one electrode being a positive high-voltage electrode 110 and the other being a negative high-voltage electrode 120. The system uses a boost circuit to convert low voltage into positive high voltage (e.g., +5kV) and negative high voltage (e.g., -5kV), which are applied to the two electrodes respectively. Thus, the voltage between the two electrodes is 10kV. Only half the driving voltage is required for a single electrode to achieve the discharge effect of conventional high voltage (10kV), greatly reducing the insulation withstand voltage requirements of the electrodes.

[0030] In this invention, the plasma jet 200 exhibits electrical neutrality by relying on the symmetrical charge compensation provided by the positive high-voltage electrode 110 and the negative high-voltage electrode 120. The plasma as a whole tends to maintain electrical neutrality. Any significant charge accumulation will generate a strong electric field, prompting the charge to redistribute to achieve equilibrium. That is, a stable distribution of positive and negative ion pairs is formed between the positive high-voltage electrode 110 and the negative high-voltage electrode 120. The number of positive ions is approximately equal to the number of electrons, achieving electrical neutralization of the charge. This eliminates the need to rely on a ground electrode to neutralize the charge, reducing costs, simplifying the structure, and eliminating the need to connect to a power socket during use.

[0031] Compared with the single high-voltage design in the prior art, the dual high-voltage design of this invention has a significant improvement in safety. In the prior art, if the ground electrode is damaged, the single high-voltage electrode can still work normally, which has a high risk. In this invention, if the positive high-voltage electrode 110 or the negative high-voltage electrode 120 is damaged, the voltage generated by the single electrode cannot ionize the gas to generate the plasma jet 200, which is safer.

[0032] Both high-voltage electrodes in this invention are suspended electrodes. The suspended electrodes are suspended relative to the ground, without grounding wires and without contact with human skin, so they cannot form a circuit with the human body and have an isolation and protection function. The induced current of the suspended electrodes to the human body is very small. Even if the positive and negative high voltage is several thousand volts, the human body will not feel any electric shock.

[0033] It should also be noted that during single high-voltage discharge, the plasma jet 200 is more likely to extend towards the object when it is close to an external conductive object. Therefore, the plasma jet 200 driven by single high voltage is more likely to diverge forward in the direction of the high voltage electrode, and the shape of the plasma jet 200 formed is not symmetrical. However, due to the basically symmetrical electric field distribution of dual high voltage, the plasma jet 200 is quasi-electrically neutral, and the symmetry of the plasma jet 200 formed is better.

[0034] In existing technologies, plasma devices using a single high-voltage electrode in conjunction with a ground electrode employ inert gases because plasma generated by the ionization of inert gases is easily uncharged / electrically neutral. However, this invention relies on the positive high-voltage electrode 110 and the negative high-voltage electrode 120 themselves to provide symmetrical charge compensation, forming a stable distribution of positive and negative ion pairs between them. The number of positive ions is approximately equal to the number of electrons, creating a uniform symmetrical electric field. This eliminates the need for inert gases and can generate plasma by ionizing non-inert gases such as air, thus reducing gas costs.

[0035] Furthermore, the absolute voltage values ​​of the positive high-voltage electrode 110 and the negative high-voltage electrode 120 differ by no more than 10% of the larger absolute value; preferably, the absolute voltage values ​​of the positive high-voltage electrode 110 and the negative high-voltage electrode 120 are equal, which can better form a stable distribution of positive and negative ion pairs between the positive high-voltage electrode 110 and the negative high-voltage electrode 120, making the number of positive ions equal to the number of electrons, achieving charge neutralization, and thus generating a plasma jet 200 that appears electrically neutral to the outside; it is understood that the electrical neutrality here does not mean absolutely uncharged, but close to electrical neutrality, and the voltage of the plasma jet 200 does not exceed the safe voltage for the human body.

[0036] Furthermore, the two discharge ends are centrally symmetrically distributed about the central axis of the plasma generation cavity 131, which enables the formation of an approximately symmetrical electric field distribution within the plasma generation cavity. This makes the gas ionization region more uniform, avoiding localized high-density or weak-ionization regions caused by unilateral ionization. Simultaneously, the plasma jet 200 exhibits better symmetry, making it easier for the jet's charge to cancel out and neutralize. The specific principle is as follows: When the absolute values ​​of the voltages of the positive high-voltage electrode 110 and the negative high-voltage electrode 120 are equal, the zero potential is located between the positive high-voltage electrode 110 and the negative high-voltage electrode 120. Since the two electrodes are centrally symmetrically distributed about the central axis of the generating cavity 131, that is, the two electrodes are symmetrically arranged on both sides of the generating cavity 131, and the line connecting the two electrodes passes through the center line of the center point of the generating cavity 131, the zero potential basically coincides with the central axis of the generating cavity 131.

[0037] Since the gas fills the generating cavity 131, it can be considered as a gas cloud with the same shape as the generating cavity 131. Therefore, the zero potential and the central axis of the gas cloud are basically coincident. The essence of the zero potential coinciding with the central axis of the generating cavity 131 is that the zero potential coincides with the central axis of the gas to be ionized. After the plasma jet 200 generated by ionization leaves the generating cavity 131, the jet head is basically coincident with the central axis of the generating cavity 131, which can form an approximately symmetrical electric field distribution within the plasma generating cavity. At this time, the jet head is located in the middle of the gas cloud. When acting on the human body, the jet is basically centrally symmetrical, the voltage is positive and negative symmetrical, and the center is close to zero potential. The charge of the jet is easily canceled and neutralized. The plasma jet 200 will not be biased towards one polarity, and the plasma jet 200 is more closely close to being electrically neutral.

[0038] Furthermore, both the positive high-voltage electrode 110 and the negative high-voltage electrode 120 are made of silver wire. Due to the high conductivity of silver, the resistance loss of the electrode itself can be significantly reduced, avoiding local overheating caused by Joule heating, which is suitable for high-current discharge scenarios of atmospheric pressure plasma jet 200. Silver has high surface stability and is not easily oxidized at room temperature, making it particularly suitable for plasma devices with high requirements for electrode stability, efficiency and lifespan.

[0039] Furthermore, the discharge gap (distance between the two discharge ends) between the positive high-voltage electrode 110 and the negative high-voltage electrode 120 is set to 2-7 mm, for example, 2 mm, 5 mm, or 7 mm. The distance between the discharge ends of the positive high-voltage electrode 110 and the negative high-voltage electrode 120 and the outlet of the generating cavity 131 is 1-4 mm, for example, 1 mm, 3 mm, or 4 mm. A suitable distance is required between the positive high-voltage electrode 110 and the negative high-voltage electrode 120 to achieve gas discharge. Simultaneously, to ensure a certain volume of discharge plasma, if the distance is too close, the discharge volume will be too small; if the distance is too far, the driving voltage will be too high, requiring a high power supply, and the discharge will be unstable, which is not conducive to generating an electric arc. Generating the plasma jet 200 requires excessive power, which is not conducive to miniaturization, and the airflow also needs to be large, which is uneconomical.

[0040] Furthermore, two electrode holes 134 are symmetrically arranged on the wall of the generating tube 130. The discharge ends of the positive high voltage electrode 110 and the negative high voltage electrode 120 are respectively inserted into the generating cavity 131 through the two electrode holes 134. Under the premise that the two electrode holes 134 are symmetrical, the same operation is performed on the positive high voltage electrode 110 and the negative high voltage electrode 120 during processing, which can ensure that the discharge ends of the two high voltage electrodes are at the same height and symmetrical, which is convenient for manufacturing.

[0041] Meanwhile, the electrode hole 134 spatially divides the entire positive high voltage electrode 110 or negative high voltage electrode 120 into two parts. One part is located inside the generating tube 130, which can avoid interference from outside the generating tube 130. At the same time, its short length can prevent changes in the position of the discharge end. The other part is located outside the generating tube 130. Due to the obstruction of the generating tube 130, even if the part of the electrode located outside the generating tube 130 is subjected to force, it is difficult to affect the part of the electrode located inside the generating tube 130. This can effectively prevent the discharge end positions of the positive high voltage electrode 110 and the negative high voltage electrode 120 from moving or even the two discharge ends from contacting each other.

[0042] Furthermore, the generating tube 130 has a single incoming gas inlet 132, which is centrally symmetrical about the central axis of the generating cavity 131. This ensures that the velocity of the incoming gas reaching the two electrodes is approximately equal, thereby maintaining the gas concentration near the two electrodes at approximately the same level and better preserving the electroneutrality of the plasma jet 200. Specifically, the cylindrical generating tube 130 is open at both ends, with one end serving as the jet end and the other end as the incoming gas inlet 132. The incoming gas flows along the axis of the cylindrical cavity, and the space at the same axial position of the generating cavity 131 is simultaneously filled with gas. That is, the discharge ends of the two electrodes are also simultaneously filled with gas, ensuring that the gas concentration near the two electrodes remains approximately the same during the initial discharge and subsequent continuous discharge.

[0043] In another embodiment, the gas inlets 132 on the generating tube 130 are provided in multiple ways. These multiple gas inlets 132 are evenly distributed around the central axis of the generating cavity 131, so that the velocity of the incoming gas reaching the two electrodes is substantially equal, thereby keeping the gas concentration near the two electrodes substantially the same. Specifically, the cylindrical generating tube 130 is open at only one end, which serves as the jet end, and the multiple gas inlets 132 are evenly distributed around the circumference of the generating tube 130.

[0044] The reason for keeping the gas concentration near the two electrodes essentially the same is that the uniformity of the gas concentration near the two electrodes would affect the uniformity of the electric field within the generating cavity 131. Specifically: As mentioned earlier, the positive high-voltage electrode 110 and the negative high-voltage electrode 120 are centrally symmetrically distributed about the central axis of the generating cavity 131, so that the zero potential coincides with the central axis of the generating cavity 131, that is, the zero potential is substantially coincident with the central axis of the gas to be ionized, thus ensuring the electroneutrality of the plasma jet 200. In reality, the gas mass within the generating cavity 131 is not static. During the generation of the plasma jet 200, gas is continuously supplied to the generating cavity 131 via the gas path assembly 150. The uniformity of the gas concentration near the two electrodes affects the uniformity of the electric field within the generating cavity 131, thereby influencing the electroneutrality of the plasma jet 200. Ensuring that the incoming gas reaches the two electrodes at substantially equal speeds, and thus maintaining substantially the same gas concentration near the two electrodes, is beneficial for maintaining the electroneutrality of the plasma jet 200.

[0045] In one embodiment, the low-temperature plasma generator 100 further includes a circuit assembly 140 and a gas path assembly 150. The circuit assembly 140 is electrically connected to the positive high-voltage electrode 110 and the negative high-voltage electrode 120, and provides positive high voltage and negative high voltage to the positive high-voltage electrode 110 and the negative high-voltage electrode 120, respectively. The gas path assembly 150 is connected to the incoming gas inlet 132 on the generator tube 130 for inputting gas flow into the generator chamber 131.

[0046] The circuit assembly 140 described above includes a high-voltage transformer 141 and a resistive impedance matching assembly 144.

[0047] The high voltage transformer 141 is used to provide positive high voltage to the positive high voltage electrode 110 and negative high voltage to the negative high voltage electrode 120. The high voltage transformer 141 is also electrically connected to a switch 142 for controlling the on and off of the circuit and a main board 143 for controlling the voltage magnitude.

[0048] The resistive impedance matching component 144 is a component that uses the resistive impedance matching method to improve current stability through a resistive network composed of resistors. There are two resistive impedance matching components 144, which correspond to the positive high voltage electrode 110 and the negative high voltage electrode 120, respectively. One end of one resistive impedance matching component 144 is connected to the positive high voltage electrode 110 and the other end is connected to the high voltage transformer 141. One end of the other resistive impedance matching component 144 is connected to the negative high voltage electrode 120 and the other end is connected to the high voltage transformer 141.

[0049] The aforementioned gas circuit assembly 150 includes a gas input pipe 151 and a gas pipe adapter 152; the two ends of the gas pipe adapter 152 are respectively connected to the gas input pipe 151 and the generating pipe 130, and the other end of the gas input pipe 151 is connected to a gas source 153, which can be configured as a gas cylinder. The gas in the gas source 153 enters the generating chamber 131 of the generating pipe 130 through the gas input pipe 151 and the gas pipe adapter 152.

[0050] Preferably, both the gas input pipe 151 and the generating pipe 130 are flexible tubes, and both flexible tubes are inserted into the gas pipe adapter 152. The gas pipe adapter 152 includes a middle partition and cylindrical interfaces fixedly connected to both ends of the partition, and the two interfaces are interconnected. The ports of the gas input pipe 151 and the generating pipe 130 are respectively wrapped around the two interfaces, and the ends of the gas input pipe 151 and the generating pipe 130 are stretched and deformed, using the elasticity of the flexible tubes themselves to fix the ports of the flexible tubes to the interfaces. The outer surface of the interfaces is relatively smooth to avoid air leakage.

[0051] The advantage of making the gas inlet pipe 151 a flexible hose is that when the gas inlet pipe 151 is installed inside the housing, it can be bent and adjusted according to the internal structure of the housing.

[0052] In one embodiment, the low-temperature plasma generator 100 further includes a housing 160, within which a mounting cavity 161 is provided. The circuit assembly 140, the gas path assembly 150, the positive high voltage electrode 110, the negative high voltage electrode 120, and the generator tube 130 are all fixedly installed in the mounting cavity 161. The housing 160 protects the internal circuit assembly 140 and gas path assembly 150.

[0053] Furthermore, the outer casing 160 includes an upper casing 162 and a lower casing 163, which are configured to be detachably connected. The detachable connection facilitates the installation of various components in the mounting cavity 161 within the casing, and also facilitates disassembly and maintenance. Specifically, the detachable connection can be a screw-fixed connection, with corresponding connection holes provided on the upper casing 162 and the lower casing 163, and the connection holes on the upper casing 162 and the lower casing 163 can be connected by screws.

[0054] Furthermore, the outer shell 160 is configured as a handpiece shell, which is convenient for users to hold and use; the outer surface of the handpiece shell is provided with an anti-slip part 165 for easy gripping, and a circumferential heat dissipation hole 166 is provided at the position corresponding to the resistive impedance matching component 144 to improve the local heat dissipation efficiency of the part where the resistive impedance matching component 144 is located.

[0055] Preferably, the handpiece housing has openings at both ends along its length. The generating tube 130 is located in one of the openings, and the gas input tube 151 enters the handpiece housing through the opening at the other end. Compared to introducing the gas input tube 151 from the side of the handpiece housing, this invention introduces the gas input tube 151 from the end of the handpiece housing, which makes the structure of the end where the generating tube 130 is located simple and neat, without external pipes interfering with the view, making it convenient for the user to operate, and also improving the flexibility of the end where the generating tube 130 is located when moving.

[0056] The outer casing 160 also includes a front cover 164, which is fitted over the opening at one end of the generating tube 130. The front cover 164 can seal the seam between the upper casing 162 and the lower casing 163 to create a seamless circumferential jet channel, preventing the plasma jet 200 from being affected by the outside air before it completely leaves the outer casing 160, thereby improving the stability and symmetry of the plasma jet 200.

[0057] The specific connection method of the front cover 164 is as follows: multiple bayonet slots 164-1 are provided on the circumferential direction of the end of the front cover 164, and corresponding locking blocks 164-2 are provided on the upper shell 162 and the lower shell 163. The front cover 164 can be connected to the front end of the upper shell 162 and the lower shell 163 by engaging the locking blocks 164-2 with the bayonet slots 164-1. Specifically, the bayonet slots 164-1 are configured to be narrow at the front and wide at the back, with the wider part at the back set as a circular notch. The locking blocks 164-2 are set as circular locking blocks. By pressing hard, the circular locking blocks can be inserted into the circular notch at the back of the bayonet slot, thereby connecting the front cover 164 with the upper shell 162 and the lower shell 163.

[0058] In this embodiment, the voltage values ​​of the plasma jets 200 generated by the ionization of inert gas and air by the dual high-voltage electrodes and the single high-voltage electrode, respectively, are also detected. The specific data are as follows: Figure 11 , Figure 12 and Figure 13 The figures show the voltage waveforms near the positive high-voltage electrode 110, the negative high-voltage electrode 120, and the jet center when ionizing argon gas with dual high-voltage electrodes using an oscilloscope. The figures show that the effective RMS values ​​of the output voltages on the two high-voltage electrode sides are 8.582V and 8.418V, respectively, both around 8.5V, with good symmetry. The effective voltage value at the jet center is approximately 8V. All three voltages are close and safe for the human body, and will not cause electric shock to human skin.

[0059] Figure 14 , Figure 15 and Figure 16 The figures show the voltage waveforms near the positive high-voltage electrode 110, the negative high-voltage electrode 120, and the jet center when the air is ionized by the dual high-voltage electrodes using an oscilloscope. The figures show that the effective RMS values ​​of the output voltages on the two high-voltage electrode sides are 14.70V and 16.85V, respectively, which are basically around 15V and have good symmetry. The effective value of the voltage at the jet center is about 18V. All three voltages are close and safe for the human body, and will not cause electric shock to the human skin.

[0060] like Figure 17 and Figure 18As shown, when an oscilloscope is used to test the air jet output when a single high-voltage electrode ionizes air, the effective value (RMS) of the voltage on the high-voltage electrode side and the center of the jet is very high, both greater than 1kV, which exceeds the safe voltage for the human body. Without the use of a ground electrode, it will inevitably cause electric shock to the human body.

[0061] like Figure 19 and Figure 20 As shown, when the argon jet output by the single high-voltage electrode is detected by an oscilloscope, the effective voltage RMS value near the high-voltage electrode exceeds 1kV, and the effective voltage RMS value at the center of the argon jet is also close to 400V, both of which exceed the safe voltage for the human body. Without the use of the ground electrode, it will inevitably cause electric shock to the human body.

[0062] It should be emphasized that the above-mentioned test data can only be discovered through experimental testing. Conventional technicians may not easily discover this characteristic, and there are certain dangers in research and testing, including the risk of electric shock.

[0063] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A low-temperature plasma generator, characterized in that, include: A positive high voltage electrode (110) is used to apply a positive high voltage when ionizing gas; A negative high-voltage electrode (120) is used to apply a negative high-voltage current when ionizing gas; The generating tube (130) is provided with a plasma jet generating chamber (131) inside the generating tube (130). The generating tube (130) is provided with an incoming gas inlet (132), a jet port (133) and an electrode hole (134) communicating with the generating chamber (131). Gas enters the generating chamber (131) through the incoming gas inlet (132), and the plasma jet (200) is ejected through the jet port (133). The discharge end of the positive high voltage electrode (110) and the discharge end of the negative high voltage electrode (120) enter the generating chamber (131) through the electrode hole (134).

2. The low-temperature plasma generator according to claim 1, characterized in that: The discharge ends of the positive high voltage electrode (110) and the negative high voltage electrode (120) are centrally symmetrically distributed about the central axis of the generating cavity (131) so as to form a uniform electric field in the generating cavity (131).

3. The low-temperature plasma generator according to claim 2, characterized in that: There are two electrode holes (134), and the two electrode holes (134) are centrally symmetrical about the central axis of the generating cavity (131).

4. The low-temperature plasma generator according to claim 1, characterized in that, Also includes: The circuit assembly (140) is electrically connected to the positive high voltage electrode (110) and the negative high voltage electrode (120) for providing positive high voltage to the positive high voltage electrode (110) and negative high voltage to the negative high voltage electrode (120); The gas path assembly (150) is connected to the incoming gas inlet (132) on the generating pipe (130) for inputting gas flow into the generating chamber (131).

5. The low-temperature plasma generator according to claim 4, characterized in that: Circuit assembly (140) includes: High voltage transformer (141) is used to provide positive high voltage and negative high voltage to positive high voltage electrode (110) and negative high voltage electrode (120). The high voltage transformer (141) is also electrically connected to a switch (142) for controlling the on and off of the circuit and a main board (143) for controlling the voltage magnitude. There are two resistive impedance matching components (144), one of which is used to connect the positive high voltage electrode (110) and the high voltage transformer (141), and the other is used to connect the negative high voltage electrode (120) and the high voltage transformer (141).

6. The low-temperature plasma generator according to claim 4, characterized in that: The gas path assembly (150) includes: A gas input pipe (151) is connected at one end to a gas source (153) for supplying gas to the generating pipe (130); The two ends of the tracheal adapter (152) are connected to the gas input pipe (151) and the gas generating pipe (130) respectively.

7. The low-temperature plasma generator according to any one of claims 4-6, characterized in that: The low-temperature plasma generator (100) also includes a housing (160), and an installation cavity (161) is provided inside the housing (160). The circuit assembly (140), the gas path assembly (150), the positive high voltage electrode (110), the negative high voltage electrode (120) and the generator tube (130) are all fixedly installed inside the installation cavity (161).

8. The low-temperature plasma generator according to claim 7, characterized in that: The housing (160) includes an upper housing (162) and a lower housing (163), which are configured to be detachably connected.

9. The low-temperature plasma generator according to claim 8, characterized in that: The outer casing (160) is configured as a hand tool casing, and openings are provided at both ends of the hand tool casing along its length. The generating pipe (130) is located in the opening at one end, and the gas input pipe (151) enters the hand tool casing through the opening at the other end.

10. The low-temperature plasma generator according to claim 9, characterized in that: The outer casing (160) also includes a front cover (164), which is fitted over the opening at one end of the generating tube (130) and can seal the seam between the upper casing (162) and the lower casing (163) to create a circumferentially seamless jet channel.

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