A plasma jet device

Abstract

The present invention relates to a plasma jet device, comprising a shell, wherein a waveguide tube and an inner tube are installed in the shell, one end of the waveguide tube is connected to a microwave power supply, a cavity is arranged between the inner tube and the waveguide tube, an air inlet which can be closed and opened is arranged on the cavity, a nozzle which is connected to the inner tube is arranged on the shell, a retractable and movable metal sheet is arranged at the nozzle, the metal sheet is in contact with a temperature sensor, the temperature sensor is connected to a controller, and the controller is also connected to a power supply and an alarm respectively. Compared with the prior art, the present invention utilizes the positive correlation between the size of the plasma jet and the size of the output power of the power supply, and by arranging the retractable and movable metal sheet, the temperature sensor and the controller, the plasma jet flux can be calculated, and the output power of the power supply can be automatically adjusted accordingly, thereby achieving the purpose of autonomously adjusting the size of the plasma jet and ensuring the stability of the output plasma jet.

Description

Technical Field

[0001] The invention relates to the field of plasma generation, in particular to a plasma jet device. Background Art

[0002] Plasma is a state in which gas molecules are partially or completely ionized after obtaining energy, and finally reach a plasma state. Gas in a plasma state is quasi-neutral, that is, it has equal but opposite charges under macroscopic space-time scale conditions. The plasma produced by atmospheric pressure plasma jet technology has a low temperature and a high concentration of active substances, so it is widely used in material modification, sterilization, environmental protection, etc.

[0003] Most current plasma jet devices use manual methods to adjust the jet size and are unable to automatically adjust the jet size as needed, resulting in unstable output jets, which is not conducive to the effective application of plasma. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a plasma jet device which can automatically adjust the jet size and output a stable jet.

[0005] The objective of the present invention can be achieved by the following technical scheme: a plasma jet device, comprising an outer shell, a waveguide tube and an inner tube installed in the outer shell, a nozzle communicating with the inner tube arranged on the outer shell, the inner tube being located below the waveguide tube, and a cavity being arranged between the inner tube and the waveguide tube, the cavity being provided with a closable and openable air inlet, one end of the waveguide tube being connected to a microwave power supply, a retractable and movable metal sheet being arranged at the nozzle, the inner tube being completely coupled to the metal sheet when the metal sheet is in an initial position, the metal sheet being in contact with a temperature sensor, the temperature sensor being further connected to an input end of a controller, and an output end of the controller being connected to a microwave power supply.

[0006] Furthermore, an operating rod is installed on the metal sheet, one end of the operating rod is provided with a handle, and the other end thereof passes through the shell and is installed on the metal sheet, and the telescopic movement of the metal sheet is achieved by pushing and pulling the operating rod.

[0007] Furthermore, sealing blocks are installed on both sides of the bottom of the cavity, and the inner conduit is installed between the two sealing blocks.

[0008] Furthermore, the output end of the controller is also connected to an alarm for prompting plasma jet flux information.

[0009] Furthermore, the controller is a programmable chip.

[0010] Furthermore, the nozzle is opened at the bottom of the shell.

[0011] Furthermore, the air inlet is opened on the side of the cavity.

[0012] Furthermore, the temperature sensor is a single-wire digital temperature sensor, specifically a DS18B20 temperature sensor.

[0013] Furthermore, the shell is a quartz shell.

[0014] The working principle of the present invention is as follows: by pushing the operating rod, the metal sheet is extended. When the plasma passes through, some particles will bombard the metal sheet, causing the metal sheet to generate a certain temperature. The temperature of the metal sheet is detected by a temperature sensor, and the measured temperature is converted from an analog signal to a digital signal for transmission to a controller. The controller reversely deduce the number of particles bombarding the metal sheet based on the measured temperature. Since the particles bombarding the metal sheet are linearly related to the entire plasma jet, the flux of the plasma jet can be calculated. Finally, according to the flux of the plasma jet, the output power of the microwave power supply is correspondingly adjusted, thereby controlling the size and stability of the output plasma jet.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The present invention sets a retractable and movable metal sheet, a temperature sensor and a controller, and reversely infers the flux of the plasma jet according to the detected temperature of the metal sheet, thereby automatically adjusting the output power of the microwave power supply to achieve the purpose of autonomously regulating the output of a stable plasma jet.

[0017] 2. The present invention adopts a single-line digital temperature sensor, which can accurately and quickly detect the temperature of the metal sheet, and adopts a programmable chip to calculate the plasma jet flux and control the power output power of the power supply. At the same time, in conjunction with an alarm, it can reliably adjust the size of the plasma jet and effectively prompt the current plasma jet information. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention;

[0019] Figure 2 It is a connection schematic diagram of the working principle of the present invention;

[0020] Figure 3 It is a schematic diagram of the working principle of the present invention;

[0021] Description of the markings in the figure:

[0022] 1. Shell, 2. Waveguide tube, 3. Air inlet, 4. Nozzle, 5. Sealing block, 6. Inner tube, 7. Metal sheet, 8. Temperature sensor, 9. Operating lever, 10. Controller, 11. Alarm, 12. Microwave power supply. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, a plasma jet device comprises a shell 1, a waveguide tube 2 and an inner tube 6 are installed in the shell 1, a nozzle 4 communicating with the inner tube 6 is provided on the shell 1, the inner tube 6 is located below the waveguide tube 2, and a cavity is provided between the inner tube 6 and the waveguide tube 2, the cavity is provided with a closable and openable air inlet 3, sealing blocks 5 are installed on both sides of the bottom of the cavity, and the inner tube 6 is installed between the two sealing blocks 5;

[0025] One end of the waveguide 2 is connected to a microwave power source 12, and a retractable metal sheet 7 is provided at the nozzle 4. When the metal sheet 7 is in the initial position, the inner conduit 6 is fully coupled with the metal sheet 7, and an operating rod 9 is installed on the metal sheet 7. A handle is provided at one end of the operating rod 9, and the other end thereof passes through the outer shell 1 and is installed on the metal sheet 7. The telescopic movement of the metal sheet 7 can be realized by pushing and pulling the operating rod 9, and a temperature sensor 8 is closely attached to the metal sheet 7.

[0026] Figure 2 The figure shows a connection schematic diagram of the working principle of the present invention, wherein the temperature sensor 8 is connected to the input end of the controller 10 to transmit the detected temperature data of the metal sheet 7 to the controller 10, and the output end of the controller 10 is respectively connected to the microwave power supply 12 and the alarm 11, and the controller 10 reversely calculates the flux of the plasma jet according to the temperature data of the metal sheet 7, and outputs control instructions to the microwave power supply 12 and the alarm 11 to automatically adjust the output power of the microwave power supply 12 and automatically issue an alarm prompt of the plasma jet flux information.

[0027] like Figure 3 As shown, after the controller 10 calculates the flux of the plasma jet, it first determines whether the flux value is within a preset normal range. If it is determined to be yes, no control signal is output to the power supply, that is, the power output power of the power supply is not adjusted. If it is determined to be no, it continues to determine whether the flux value is less than a preset low value.

[0028] If the determination is yes, a control signal is output to the power supply to increase the output power of the power supply. If the determination is no, whether the flux value is greater than a preset high value is further determined.

[0029] If the judgment is yes, a control signal is output to the power supply to reduce the output power of the power supply.

[0030] In this embodiment, the housing is a quartz housing, the power supply is a microwave power supply with controllable output power, the controller adopts a programmable chip, and the temperature sensor is a single-line digital temperature sensor, specifically a DS18B20 temperature sensor, which adopts a single bus interface mode. When connected to the controller, only one data line is needed to realize two-way communication between the controller and the DS18B20. The single bus has the advantages of good economy and strong anti-interference ability, and is suitable for on-site temperature measurement in harsh environments; in addition, the measurement range of DS18B20 is -55℃~+125℃, and within the range of -10~+85℃, the accuracy is ±0.5℃, and the resolution is 0.0625℃, indicating that it has a wide temperature measurement range and high measurement accuracy; DS18B20 does not require any peripheral components during use, and multiple DS18B20 can be connected in parallel on one line to achieve multi-point temperature measurement; DS18B20 can obtain power from the data line through an internal parasitic circuit. Therefore, when the timing on the data line meets certain requirements, no external power supply is required, making the system structure simpler and more reliable; DS18B2 contains EEPROM inside, which can still save the resolution and alarm temperature setting values ​​after the system loses power.

[0031] The present invention utilizes the relationship that the size of the jet generated by the plasma jet device is positively correlated with the power size of the power supply of the device, that is, the larger the power of the power supply, the larger the jet, and the smaller the power of the power supply, the smaller the jet. In this way, the size of the plasma jet is changed by changing the size of the power supply. The actual working process of the present invention is: open the air inlet 3, allow the gas to pass through the air inlet 3, the microwave power supply transmits the microwave to the cavity through the waveguide 2, and then close the air inlet 3, combined with the effect of the sealing block 5, so that the cavity forms a closed resonant cavity, the microwave forms a stable distributed electromagnetic field inside the resonant cavity, the local enhanced electric field causes ionization, and forms plasma, and the plasma jets from the inner conduit 6. In order to adjust the flux of the plasma jet, the operating rod 9 is pushed into the inside of the shell 1 to make the metal sheet 7 extend. At this time, some particles in the jet will bombard the metal sheet 7, thereby generating heat. The temperature sensor 8 is closely attached to the metal sheet 7. Since the temperature change range of the metal sheet is relatively small, an accurate and highly sensitive temperature sensor should be used. The temperature sensor 8 transmits the obtained temperature information to the controller 10, and the controller 10 determines the flux of the plasma jet at this time according to the relationship between the temperature information obtained at this time and time, and adjusts the output power of the microwave power supply through a pre-set program to achieve the purpose of controlling the plasma jet flux. If the current plasma jet flux exceeds the preset limit, a control signal is output to the alarm to issue an alarm prompt that the plasma jet flux exceeds the limit. After adjustment, if the plasma jet flux reaches the required flux, according to the pre-set program, a control signal is output to the alarm to issue an alarm prompt that the plasma jet flux meets the requirements. At this time, pull back the operating rod 9 to return the metal sheet 7 to the initial position and restore the state of complete coupling with the inner conduit 6 to avoid any impact on the next plasma jet.

Claims

1. A plasma jet device, comprising a housing (1), a waveguide tube (2) and an inner tube (6) being installed in the housing (1), a nozzle (4) being provided on the housing (1) and communicating with the inner tube (6), the inner tube (6) being located below the waveguide tube (2), characterized in that: A cavity is provided between the inner conduit (6) and the waveguide (2), the cavity is provided with an air inlet (3) that can be closed and opened, one end of the waveguide (2) is connected to a microwave power source (12), a retractable and movable metal sheet (7) is provided at the nozzle (4), when the metal sheet (7) is in an initial position, the inner conduit (6) and the metal sheet (7) are completely coupled, the metal sheet (7) is in contact with a temperature sensor (8), the temperature sensor (8) is also connected to an input end of a controller (10), and an output end of the controller (10) is connected to the microwave power source (12); An operating rod (9) is mounted on the metal sheet (7), one end of the operating rod (9) is provided with a handle, and the other end of the operating rod (9) passes through the housing (1) and is mounted on the metal sheet (7), so that the metal sheet (7) can be telescopically moved by pushing and pulling the operating rod (9); The metal sheet (7) is extended by pushing the operating rod (9). When the plasma passes through, some particles will bombard the metal sheet (7), causing the metal sheet (7) to generate a certain temperature. The temperature of the metal sheet (7) is detected by the temperature sensor (8), and the measured temperature is converted from an analog signal to a digital signal for transmission to the controller (10). The controller (10) reversely derives the number of particles bombarding the metal sheet (7) based on the measured temperature. Since the number of particles bombarding the metal sheet (7) is linearly related to the entire plasma jet, the flux of the plasma jet can be calculated. Finally, according to the flux of the plasma jet, the output power of the microwave power supply (12) is adjusted accordingly, thereby controlling the size and stability of the output plasma jet. Sealing blocks (5) are installed on both sides of the bottom of the cavity, and the inner conduit (6) is installed between the two sealing blocks (5); The output end of the controller (10) is also connected to an alarm (11) for prompting plasma jet flux information.

2. A plasma jet device according to claim 1, characterized in that: The controller (10) is a programmable chip.

3. A plasma jet device according to claim 1, characterized in that: The air inlet (3) is opened on the side of the cavity.

4. A plasma jet device according to claim 1, characterized in that: The nozzle (4) is opened at the bottom of the shell (1).

5. The plasma jet device according to claim 1, characterized in that: The temperature sensor (8) is specifically a single-line digital temperature sensor.

6. A plasma jet device according to claim 1, characterized in that: The housing (1) is a quartz housing.

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