Low temperature plasma atomization apparatus and method

Abstract

The application discloses a low-temperature plasma atomization device and method, and belongs to the technical field of plasma atomization. The plasma atomization device comprises a plasma generation module, a primary atomization module and a secondary atomization module. The high-speed airflow in the primary atomization module rapidly tears the liquid in the water channel into small droplets and drives the droplets to form a spray. The secondary atomization module is arranged at the end of the primary atomization module. The secondary atomization module is provided with working gas of corresponding types and flow rates through the inclined atomization holes in the sidewall of the atomization pipe. The plasma generation module is installed in the atomization pipe. Through the activation process of gas-liquid mass transfer, different active substances with different proportions of RNS and ROS are obtained, and the second specific atomization of the liquid is realized. The high-voltage electrodes of the primary atomization module and the plasma generation module are applied with direct current voltages with opposite polarities. The application realizes the synergistic control of the volume, droplet diameter and active components of the plasma-activated water mist through multiple atomization, and meets the regulation and control requirements of specific application scenarios.

Description

Technical Field

[0001] This invention belongs to the field of plasma atomization technology and relates to a low-temperature plasma atomization device and method. Background Technology

[0002] Low-temperature plasma activated water works by exposing water molecules to a plasma field, exciting the chemical bonds within and around the water molecules, thus endowing them with higher activity and chemical reactivity. Plasma-activated water mist is an innovation based on low-temperature plasma activated water technology. By spraying plasma-activated water in a mist form, it allows the molecules to better contact the environment, effectively increasing its effective surface area. Compared to traditional plasma activated water treatment methods, the application of water mist not only more evenly covers the target surface but also rapidly transfers active ingredients to the surface upon droplet adhesion, achieving a more efficient treatment effect. This new form of plasma-activated water mist demonstrates stronger effects in cleaning, disinfection, and deodorization, and is more suitable for specialized applications such as precision agricultural spraying and air purification.

[0003] Chinese patent CN 115413102 A discloses a plasma generating device and an electrostatic sprayer for generating plasma-activated mist. Its main purpose is to charge the water mist so that it can adhere to the surface of objects, but it is difficult to meet the control requirements of specific application scenarios.

[0004] Existing plasma water spray devices typically employ a single-atomization design, making it difficult to achieve coordinated control of water mist volume, droplet diameter, and liquid active ingredients (oxygen-containing or nitrogen-containing active particles). This limits the application and widespread adoption of plasma-activated water technology. For example, in agriculture, it is necessary to fine-tune the droplet diameter and active ingredient content of the water mist according to the crop's growth stage and pest and disease conditions to achieve optimal protective effects. However, adjusting a single parameter (voltage, airflow, etc.) often fails to meet this requirement. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a low-temperature plasma atomization device that enables coordinated control of parameters such as plasma-activated water mist volume, droplet diameter, and active components through multiple atomization processes. This meets the regulation requirements of specific application scenarios and solves the problems existing in the prior art.

[0006] Another objective of this invention is to provide a low-temperature plasma atomization method.

[0007] The technical solution adopted in this invention is a low-temperature plasma atomization device, including a plasma generating module, and further comprising:

[0008] The primary atomization module, in which a high-speed airflow rapidly tears the liquid in the water path into small droplets, and drives the droplets to form a spray, thus completing the primary atomization;

[0009] A secondary atomization module is located at the end of the primary atomization module. The secondary atomization module introduces working gas of the corresponding type and flow rate through the inclined atomization holes on the side wall of the atomization tube. The plasma generation module is installed inside the atomization tube and obtains reactive substances with different proportions of RNS and ROS through the gas-liquid mass transfer activation process, thereby realizing the second specific atomization of the liquid.

[0010] In this process, the high-voltage electrode of the primary atomization module and the high-voltage electrode of the plasma generation module are subjected to DC voltages of opposite polarities.

[0011] Furthermore, the high-voltage electrode in the primary atomization module applies a DC negative voltage lower than the gas breakdown voltage, which does not generate gas discharge plasma, causing the droplets to carry a negative charge and realizing the first energy atomization of the liquid.

[0012] A DC positive voltage is applied to the high-voltage electrode of the plasma generation module, and active substances with different proportions of RNS and ROS are obtained through the gas-liquid mass transfer activation process, thereby achieving the second specific atomization of the liquid.

[0013] Alternatively, a positive DC voltage can be applied to the high-voltage electrode of the primary atomization module, and a negative DC voltage can be applied to the high-voltage electrode of the plasma generation module.

[0014] Furthermore, it also includes an electrostatic atomization module, which consists of a high-voltage electrode and a diffuser. The high-voltage electrode, based on the principle of inductive charging, can charge the droplets that have completed secondary atomization in the atomization tube while generating plasma. The diffuser is a conical cylinder installed at the end of the atomization tube and connected to the ground electrode of the primary atomization module. When the droplets are blown out of the atomization tube by gas, the grounded diffuser attracts the charged droplets because the droplets are charged, completing the tertiary atomization. At the same time, the droplets carry the same charge and repel each other, enabling further atomization.

[0015] Furthermore, the primary atomization module includes a three-way pipe. The first port of the three-way pipe is connected to the main air pump, and the second port of the three-way pipe is connected to the peristaltic pump to precisely control the water flow rate entering the three-way pipe. The third port of the three-way pipe is connected to the outlet through a throat pipe to create a pressure difference at the outlet, which assists the high-speed airflow in primary atomization. The high-speed airflow is introduced through the main air pump to quickly tear the liquid in the water path into small droplets and drive the droplets to form a spray, thus completing primary atomization.

[0016] Furthermore, the primary atomization module also includes a negative high-voltage charging module, which consists of a negative high-voltage needle and a ground electrode. The positive terminal of the high-voltage power supply is grounded, and the negative terminal is connected to the negative high-voltage needle. At this time, the negative high-voltage needle has a negative voltage. The negative high-voltage needle is installed inside the air inlet, that is, inside the first port of the three-way tube. The negative high-voltage needle applies a DC negative voltage, which is lower than the gas breakdown voltage, so that no gas discharge plasma is generated, causing the droplets to carry a negative charge, thereby realizing the first charging atomization of the liquid.

[0017] Furthermore, the secondary atomization module includes an atomizing tube, which is a hollow cylindrical structure connected to the outlet of a three-way pipe. The side wall of the atomizing tube is provided with multiple atomizing holes with different inclinations along the axial direction. The diameter of the atomizing holes is 2-3 mm. The outer periphery of the atomizing tube is covered with an annular air chamber. The air chamber is driven by a moving module and can move axially on the outer wall of the atomizing tube. The air chamber is connected to a branch air pump, which drives the airflow into the air chamber and into the atomizing tube through the corresponding atomizing holes. The airflow shears the droplets of the primary atomized spray in the vertical direction, thus completing the secondary atomization.

[0018] Furthermore, the droplet diameter after secondary atomization is controlled collaboratively by the primary atomization module and the secondary atomization module. That is, depending on the gas flow rate of the main air pump and the peristaltic pump, the corresponding atomization orifice angle and the gas flow rate of the branch air pump are controlled.

[0019] Furthermore, the plasma generating module includes a high-voltage electrode and a metal ground electrode. The high-voltage electrode is a metal needle electrode, and the sleeve outside the gas chamber serves as the metal ground electrode. The metal needle electrode is subjected to a sufficiently high DC voltage, which causes the gas in the atomizing tube to ionize and generate plasma.

[0020] Furthermore, the working gas driven by the branch pump in the secondary atomization module is one or more of oxygen, nitrogen, carbon dioxide, hydrogen, air, carbon tetrafluoride, sulfur dioxide or ammonia in any ratio combination. Different gas discharge plasmas are generated in the atomization tube. Through the gas-liquid mass transfer activation process, the water mist is rich in specific active components, namely RNS and ROS. Different types and flow rates of working gas result in different proportions of RNS and ROS.

[0021] The gas in the primary atomization module is an inert gas, or a gas of the same type as the working gas in the secondary atomization module.

[0022] A method for atomizing a low-temperature plasma atomizing device includes the following steps:

[0023] S1, select the gas flow rate of the main air pump and the water pumping volume of the peristaltic pump according to the required droplet diameter; connect the branch air pump to the corresponding gas cylinder as needed; start the main air pump and drive the gas chamber to move to the atomization hole with the corresponding inclination on the outer wall of the atomizing tube through the moving module.

[0024] S2, the plasma power supply simultaneously supplies power to the high-voltage electrode in the primary atomization module and the high-voltage electrode in the secondary atomization module; at this time, the peristaltic pump is started to pump a metered amount of water in, and the primary atomization and charging are completed in the primary atomization module to generate a negatively charged spray with larger droplets;

[0025] S3, the negatively charged spray enters the secondary atomization module. The branch air pump pumps the working gas into the secondary atomization module. The branch air flows through the air chamber and enters the atomization tube from the atomization hole, shearing the large droplet spray and performing secondary atomization to form a finer spray. At the same time, the plasma generation module ionizes the working gas, generating a large amount of plasma in the cavity area between the high-voltage electrode and the atomization tube, forming a plasma spray.

[0026] S4, the plasma spray carries a positive charge under the action of high voltage electricity. Driven by high-speed airflow, the finer spray after being charged is ejected. After passing through the grounded diffuser, it is further attracted and diffused by the diffuser, completing three atomizations to form a fine spray.

[0027] The beneficial effects of this invention are:

[0028] 1. The water mist charging process in the primary atomization and the plasma activation process in the secondary atomization mutually promote each other, effectively reducing the gas discharge voltage and enhancing the plasma activation effect of the water mist.

[0029] 2. During secondary atomization, the air pump parameters and gas composition can be adjusted as needed to generate plasma sprays with different compositions for different scenarios; at the same time, plasma carries out gas-liquid mass transfer of active substances during secondary atomization, and the larger specific surface area further improves plasma activation efficiency.

[0030] 3. Multiple atomization processes can achieve coordinated control of parameters such as plasma-activated water mist volume, droplet diameter, and active components, further enhancing the application advantages of low-temperature plasma-activated water in drinking water purification, industrial production, and agricultural yield increase, promoting technological development and progress in related fields, and meeting the control needs of corresponding application scenarios. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the external structure of an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the internal structure of an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram of the three-way pipe structure in an embodiment of the present invention.

[0035] Figure 4 This is a schematic diagram of the structure of the moving module and the charging atomizing module in an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of the internal airflow direction in an embodiment of the present invention.

[0037] In the diagram: 1. Moving module; 2. Electrostatic atomization module; 3. Primary atomization module; 4. Main air pump; 5. Secondary atomization module; 6. Diffuser tube; 7. Plasma generation module; 8. Negative high-voltage charging module; 9. T-connector; 10. Peristaltic pump; 11. Air inlet; 12. Ground electrode; 13. Outlet; 14. Throat tube; 15. Negative high-voltage needle; 16. Water inlet; 17. Front plate; 18. Lead screw; 19. Gas chamber body; 20. Connector; 21. Sleeve; 22. Rear plate; 23. Atomizing tube; 24. Sealing ring; 25. High-voltage needle; 26. Branch air pump. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1:

[0040] A low-temperature plasma atomization device includes a primary atomization module 3, a secondary atomization module 5, a plasma generation module 7, a moving module 1, a main air pump 4, a branch air pump 26, a peristaltic pump 10, an electrostatic atomization module 2, etc.

[0041] like Figure 1-3 As shown, the primary atomization module 3 consists of a main air pump 4, a peristaltic pump 10, a three-way pipe 9, and a negative high-pressure charging module 8. The three-way pipe 9 consists of an air inlet 11, a water inlet 16, a throat 14, and an outlet 13. The air inlet 11 is connected to the main air pump 4, and the water inlet 16 is connected to the peristaltic pump 10, which can precisely control the water flow rate entering the three-way pipe 9. The structure of the throat 14 can create a pressure difference at the outlet 13 to assist the high-speed airflow in primary atomization. The main air pump 4 introduces high-speed gas, which can quickly tear the liquid in the water path into small droplets and drive the droplets to form a spray, thus completing primary atomization.

[0042] The negative high-voltage charging module 8 consists of a metal needle electrode (i.e., negative high-voltage needle 15) and a ground electrode 12. The positive terminal of the high-voltage power supply is grounded to generate a negative high-voltage effect, making the spray negatively charged. The negative terminal is connected to the negative high-voltage needle 15, at which time the negative high-voltage needle 15 has a negative voltage. The negative high-voltage needle 15 is installed in the air inlet 11. The negative high-voltage needle 15 applies a DC negative voltage, which is lower than the gas breakdown voltage, so no gas discharge plasma is generated. The primary atomized spray is charged with negative high voltage, so that the droplets carry a negative charge, realizing the first charging atomization of the liquid.

[0043] In the secondary atomization module 5, the high-voltage electrode (i.e., the high-voltage electrode of the plasma generation module 7) applies a positive DC voltage, which corresponds to the negatively charged water spray after the first charging atomization, reducing the gas breakdown discharge voltage and enhancing the plasma activation effect of the water mist. At the same time, different types of working gases (nitrogen, air, argon, oxygen, etc., depending on the user's personal needs) and flow rates (the flow rate is determined according to the user's requirements for droplet diameter) are selectively introduced to generate specific active ingredients for different scenarios, realizing the second specific atomization of the liquid.

[0044] The secondary atomization module 5 is located at the end of the three-way pipe 9 and consists of a branch air pump 26, a gas chamber, an atomizing tube 23, and a plasma generation module 7. The atomizing tube 23 is a hollow cylindrical structure located behind the three-way pipe 9, with an array of atomizing holes on its inner wall, which connect to the gas chamber. The atomizing holes are multiple sets of small holes at an angle of 40°-90° to the horizontal line of the atomizing tube 23, with a diameter of 2-3 mm, obtained from experiments and simulation tests. A diameter that is too small or too large is not conducive to atomization. If the diameter is too small, the gas velocity in the branch air path will be too fast under the same gas flow rate (the gas flow rate remains the same, but the hole becomes smaller, and the gas velocity becomes faster), which will result in a more concentrated effect of the branch air path on the main air path, a smaller effective area, a relatively uneven atomization process, and a poor atomization effect. If the diameter is too large, the flow rate will be too low. Although the effective area is larger, the velocity is too low to provide sufficient impact on the main air path. That is, the diameter of the atomizing hole is obtained by combining the velocity of the branch air path and the effective area.

[0045] The air chamber is a hollow structure that surrounds the atomizing tube 23. The branch air pump 26 drives the airflow into the air chamber, which then enters the atomizing tube 23 (branch air path) through the atomizing hole. The airflow shears the droplets of the atomized spray in the vertical direction to complete the secondary atomization.

[0046] The primary atomization module 3 controls the total volume of plasma-activated water mist, while the secondary atomization module 5 controls the types of active ingredients in the water mist (controlled by different working gases, i.e., the proportion of RNS and ROS). The two modules work together to control the diameter of the water mist droplets.

[0047] Example 2:

[0048] like Figure 4As shown, the multiple sets of atomizing orifices are at multiple angles, forming angles of 40°-45°, 55°-60°, 70°-75°, and 85°-90° with the horizontal line of the atomizing tube 23 from the front end to the back end. According to current experimental results, the larger the angle, the stronger the shearing effect; angles greater than these will cause gas backflow. As the gas flow rate in the branch gas path increases, the corresponding angles also increase, as shown in Table 1. The gas flow rate in the main gas path is determined by the water flow rate of the peristaltic pump 10, and it increases continuously with the increase of the water flow rate. The gas flow rate in the branch gas path depends on the gas flow rate in the main gas path; if it is too large, it will easily cause backflow, and if it is too small, the atomization effect will be poor.

[0049] Table 1. Airflow rate in the gas path, corresponding droplet diameter, and atomizing orifice angle.

[0050]

[0051] The moving module 1 consists of a motor, a lead screw 18, a front plate 17, a connector 20, a rear plate 22, and a control system. The front and rear ends of the lead screw 18 are rotatably connected to the front plate 17 and the rear plate 22, respectively. One end of the connector 20 is threadedly connected to the lead screw 18, and the other end of the connector 20 is fixedly connected to the air chamber body 19. The front plate 17 is fitted onto the front end of the atomizing tube 23, and the rear plate 22 is fitted onto the rear end of the venturi tube. The motor drives the lead screw 18 to rotate, which in turn causes the connector 20 to move the air chamber horizontally on the outer wall of the atomizing tube 23. Different inclination angles of the atomizing holes can be selected according to the air flow rate of the main air path. The control system can control the motor and the air pumps corresponding to the main and branch air paths to move the air chamber and maintain the air flow rate of the branch air path and the main air path.

[0052] The air chamber is composed of a sleeve 21, a sealing ring 24, and an air chamber body 19, all of which are made of conductive materials. The front and rear ends of the air chamber body 19 are equipped with sleeves 21. A sealing ring 24 is provided at the connection between the air chamber body 19 and the outside air. When the air chamber moves left and right, the sleeves 21 can cover other air inlets to prevent air leakage.

[0053] The atomization effect primarily depends on the gas flow rate of the main air pump 4, which users can adjust according to the water volume. There are two coupling relationships between the branch air path and the main air path: the orifice angle and the branch air path flow velocity. These coupling relationships were derived through experiments and simulations. Different entry angles and gas velocities correspond to different gas flow velocities in the main air path, allowing for dynamic control of the atomization effect to meet users' actual needs for different droplet diameters.

[0054] Different tilt angles of atomizing holes are used to meet the secondary atomization requirements. Combined with mechanical control, the droplet diameter can be changed at any time.

[0055] Example 3:

[0056] The working gas driven by the branch pump 26 in the secondary atomization module 5 is one or more of the following in any proportion: oxygen, nitrogen, carbon dioxide, hydrogen, air, carbon tetrafluoride, sulfur dioxide, or ammonia. Different gas discharge plasmas are generated within the atomization tube 23. Through a gas-liquid mass transfer activation process, the water mist is enriched with specific active components, primarily RNS (NO2). - NO3 - NO - etc.) and ROS(O2) - Different working gases (such as OH, H2O2, O3, etc.) result in different proportions of RNS and ROS. Users only need to change the working gas to make the proportion of the components they need higher.

[0057] The main applications of plasma-activated water currently include environmental disinfection, serving as nitrogen fertilizer, and promoting plant growth. The proportion of active ingredients in the final plasma mist varies depending on whether the gaseous or liquid phase of the plasma-activated water is used. For example, if a user requires nitrogen fertilizer, nitrogen gas is used as the working gas, resulting in a significantly higher nitrogen content in the activated mist compared to using air. Users can choose the appropriate gas based on their needs.

[0058] In the primary atomization module 3, the gas in the main air pump 4 can be an inert gas (including helium, argon, neon, etc.). The discharge of the inert gas in the secondary atomization module 5 will not change the type of oxygen-containing or nitrogen-containing active particles. On the contrary, because the breakdown voltage of the inert gas is lower, it is more conducive to discharge. The gas in the main air pump 4 can also be other working gases such as oxygen, nitrogen, carbon dioxide, and air. In this case, the type of gas must be consistent with the gas in the branch air pump 26.

[0059] Example 4:

[0060] The plasma generating module 7 includes a high-voltage electrode and a ground electrode. The high-voltage electrode is a metal needle electrode (i.e., high-voltage needle 25). The sleeve 21 of the gas chamber acts as a metal ground electrode and is tightly attached to the atomizing tube 23. The metal needle electrode applies a sufficiently high DC positive voltage to ionize the gas inside the atomizing tube 23 to generate plasma. In particular, multiple pointed protrusions can be added to the surface of the metal needle electrode to reduce the discharge voltage.

[0061] The plasma power supply applies a voltage of 3000V or higher to the high-voltage electrode. After being energized, the gas between the high-voltage electrode and the ground electrode is ionized, generating diffused plasma. In the atomizing tube 23, the high-speed gas flow after the first atomization carries small droplets. After the second atomization, a finer spray is generated. After plasma activation, a plasma-activated spray is generated.

[0062] The DC negative and DC positive voltages in the primary atomization module 3 and the secondary atomization module 5 are interchangeable. When the high-voltage electrode in the primary atomization module 3 is DC positive and the high-voltage electrode in the secondary atomization module 5 is DC negative, the main functions of the two modules remain unchanged. The difference is that the primary atomization module 3 makes the water mist positively charged. When the water mist moves to the secondary atomization module 5 under the action of airflow, the secondary atomization module 5 is DC negative. Since the two are still opposite charges at this time, the DC negative voltage corresponds to the positively charged water spray after the first charging atomization, which still has the effect of reducing the gas breakdown discharge voltage and enhancing the plasma activation effect of the water mist.

[0063] Example 5:

[0064] The electrostatic atomization module 2 consists of a high-voltage extended electrode and a diffuser tube 6. The high-voltage extended electrode is the high-voltage electrode in the plasma generation module 7. Based on the principle of inductive charging, it can charge the droplets that have completed secondary atomization in the atomization tube while generating plasma. The diffuser tube 6 is a conical cylinder placed at the end of the atomization tube 23. The diffuser tube 6 is connected to the ground electrode 12. When the droplets are blown out of the atomization tube 23 by gas, they pass through the diffuser tube 6. Because the droplets are charged, the grounded diffuser tube 6 can attract the charged droplets, completing the tertiary atomization. At the same time, the droplets carry the same charge and repel each other, allowing for further atomization. This embodiment of the invention utilizes the repulsion of like charges in conjunction with the diffuser tube 6 to complete electrostatic atomization.

[0065] Example 6:

[0066] A method for atomizing a low-temperature plasma atomizing device, such as Figure 5 As shown, it includes the following steps:

[0067] S1, when plasma spraying is required, the user turns on the device and selects the gear (i.e., adjusts the gas flow rate of the air pump according to the droplet diameter and selects the required spray water volume). According to the requirements, the branch air pump 26 is connected to the corresponding gas cylinder. The control module controls the output of the main air pump 4 and controls the screw 18 to rotate, driving the gas chamber to move to the atomization hole with the corresponding inclination.

[0068] S2, the plasma power supply simultaneously powers the high-voltage metal needles in the primary atomization module 3 and the secondary atomization module 5. At this time, the peristaltic pump 10 starts working, pumping a metered amount of water into the three-way pipe 9, completing one atomization and charging in the primary atomization module 3, generating a negatively charged spray with larger droplets.

[0069] S3, the negatively charged spray enters the secondary atomization module 5. At this time, the branch air pump 26 pumps the working gas into the secondary atomization module 5, and the branch air flows through the air chamber and enters the atomization tube 23 through the atomization hole. At this time, the main and branch air paths converge, and through the coordination of the gas flow rates of the main and branch air paths, the large droplet spray is sheared at a specific angle from the atomization hole to perform secondary atomization, forming a finer spray. The plasma-activated water spray is carried out simultaneously. Different working gases are ionized, thereby generating a large amount of plasma in the cavity region between the high-voltage electrode and the atomization tube 23, forming a plasma spray.

[0070] S4, the plasma spray carries a positive charge under the action of high voltage electricity. Driven by the high-speed airflow, the finer spray after being charged is ejected. After passing through the grounded diffuser 6, it is further attracted and diffused by the diffuser 6, completing three atomizations to form a fine spray.

[0071] This invention, based on the coupled plasma jet activation of water process and spraying process, adds multiple atomization structures and utilizes dual air pumps to coordinate and control the coupled electrostatic atomization process to complete multiple atomizations of plasma-activated water spray. The synergistic use of charging and activation processes improves plasma activation efficiency. Simultaneously, the user can adjust the main air pump 4 and the branch air pump 26 as needed to generate plasma sprays with different compositions for different scenarios. The plasma spray is adjusted for different gas flow rates, and secondary atomization of the spray is completed using different atomization orifices and matching mechanical structures.

[0072] The main difficulty of the dual-pump synergy technology lies in coordinating the airflow between the pumps. Specifically, it requires coordinating the flow rates of the peristaltic pump 10, the main pump 4, and the branch pump 26, as well as the angle of the atomizing holes in the atomizing tube. Only when all parameters are confirmed can the corresponding droplet diameter be achieved. Since there are many parameters involved, the corresponding equations are difficult to derive. In this embodiment of the invention, an experimental method is used to determine the parameters. A large number of tests are conducted, and the experimental data in Table 1 are finally obtained.

[0073] Existing electrostatic spraying systems charge the droplets at the nozzle. This invention employs a pre-charging followed by activation (i.e., charging is not performed at the nozzle), thus improving both plasma activation and charging efficiency. The most crucial parameter for plasma activation is the high-voltage electrode voltage; higher voltage ensures more thorough activation and increases the concentration of active ingredients. The charging process imparts a negative charge to the droplets, meaning that the discharge voltage can be increased after the droplets enter the activation phase (the high-voltage electrode voltage remains unchanged, but the droplets are negatively charged, increasing the voltage difference and thus the discharge voltage). Simultaneously, plasma activation generates high-energy electrons, further enhancing the negative charge on the droplets and improving the electrostatic atomization module's effectiveness.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A low-temperature plasma atomization device, comprising a plasma generating module (7), characterized in that, Also includes: The primary atomization module (3) rapidly tears the liquid in the water path into small droplets, and drives the droplets to form a spray, thus completing the primary atomization. The secondary atomization module (5) is located at the end of the primary atomization module (3). The secondary atomization module (5) introduces working gas of the corresponding type and flow rate through the inclined atomization hole on the side wall of the atomization tube (23). The plasma generation module (7) is installed inside the atomization tube (23). Through the gas-liquid mass transfer activation process, reactive substances with different proportions of RNS and ROS are obtained, thereby realizing the second specific atomization of the liquid. In this process, the high-voltage electrode of the primary atomization module (3) and the high-voltage electrode of the plasma generation module (7) are subjected to DC voltages of opposite polarities; The high-voltage electrode in the primary atomization module (3) applies a DC negative voltage lower than the gas breakdown voltage, which does not generate gas discharge plasma, so that the droplets carry a negative charge and realize the first energy atomization of the liquid. The high-voltage electrode of the plasma generation module (7) applies DC positive pressure, and through the gas-liquid mass transfer activation process, reactive substances with different proportions of RNS and ROS are obtained, thereby realizing the second specific atomization of the liquid. Alternatively, a positive DC voltage is applied to the high-voltage electrode in the primary atomization module (3), and a negative DC voltage is applied to the high-voltage electrode in the plasma generation module (7).

2. The low-temperature plasma atomizing device according to claim 1, characterized in that, It also includes an electrostatic atomization module (2), which consists of a high-voltage electrode and a diffuser (6). The high-voltage electrode, based on the principle of inductive charging, can charge the droplets that have completed secondary atomization in the atomization tube while generating plasma. The diffuser (6) is a conical cylinder installed at the end of the atomization tube (23). The diffuser (6) is connected to the ground electrode (12) of the primary atomization module (3). When the droplets are blown out of the atomization tube (23) by the gas, the ground diffuser (6) attracts the charged droplets because the droplets are charged, thus completing the tertiary atomization. At the same time, the droplets carry the same charge and repel each other, thus enabling further atomization.

3. The low-temperature plasma atomizing device according to claim 1, characterized in that, The primary atomization module (3) includes a three-way pipe (9). The first port of the three-way pipe (9) is connected to the main air pump (4), and the second port of the three-way pipe (9) is connected to the peristaltic pump (10) to finely control the water flow rate entering the three-way pipe (9). The third port of the three-way pipe (9) is connected to the outlet (13) through the throat pipe (14) to form a pressure difference at the outlet (13) to assist the high-speed airflow in primary atomization. The high-speed airflow is introduced through the main air pump (4) to quickly tear the liquid in the water path into small droplets and drive the droplets to form a spray, thus completing primary atomization.

4. The low-temperature plasma atomizing device according to claim 3, characterized in that, The primary atomization module (3) also includes a negative high-voltage charging module (8), which consists of a negative high-voltage needle (15) and a ground electrode (12). The positive terminal of the high-voltage power supply is grounded, and the negative terminal is connected to the negative high-voltage needle (15). At this time, the negative high-voltage needle (15) is negatively charged. The negative high-voltage needle (15) is installed in the air inlet (11), that is, in the first port of the three-way pipe (9). The negative high-voltage needle (15) applies a DC negative voltage, which is lower than the gas breakdown voltage, so that no gas discharge plasma is generated, allowing the droplets to carry negative charges and realizing the first charging atomization of the liquid.

5. The low-temperature plasma atomizing device according to claim 4, characterized in that, The secondary atomization module (5) includes an atomizing tube (23), which is a hollow cylindrical structure and connected to the outlet (13) of the three-way pipe (9). The side wall of the atomizing tube (23) is provided with multiple atomizing holes with different inclinations along the axial direction. The diameter of the atomizing holes is 2-3 mm. The outer periphery of the atomizing tube (23) is covered with an annular air chamber. The air chamber is driven by the moving module (1) and can move axially on the outer wall of the atomizing tube (23). The air chamber is connected to a branch air pump (26). The branch air pump (26) drives the airflow into the air chamber and enters the atomizing tube (23) through the corresponding atomizing hole. The air chamber shears the droplets of the primary atomized spray in the vertical direction to complete the secondary atomization.

6. The low-temperature plasma atomizing device according to claim 5, characterized in that, The diameter of the droplets after secondary atomization is controlled by the primary atomization module (3) and the secondary atomization module (5) in a coordinated manner. That is, as the gas flow rate of the main air pump (4) and the flow rate of the peristaltic pump (10) are different, the corresponding atomization hole angle and the gas flow rate of the branch air pump (26) are controlled.

7. The low-temperature plasma atomizing device according to claim 5, characterized in that, The plasma generating module (7) includes a high-voltage electrode and a metal ground electrode. The high-voltage electrode is a metal needle electrode, and the sleeve (21) outside the gas chamber serves as the metal ground electrode. The metal needle electrode applies a sufficiently high DC voltage to ionize the gas in the atomizing tube (23) to generate plasma.

8. The low-temperature plasma atomizing device according to claim 5, characterized in that, The working gas driven by the branch air pump (26) in the secondary atomization module (5) is one or more of oxygen, nitrogen, carbon dioxide, hydrogen, air, carbon tetrafluoride, sulfur dioxide or ammonia in any ratio combination. Different gas discharge plasmas are generated in the atomization tube (23). Through the gas-liquid mass transfer activation process, the water mist is rich in specific active components. The active components are RNS and ROS. Different types and flow rates of working gas result in different proportions of RNS and ROS. The gas in the primary atomization module (3) is an inert gas, or a gas of the same type as the working gas in the secondary atomization module (5).

9. The atomization method of the low-temperature plasma atomization device as described in claim 2, characterized in that, Includes the following steps: S1, select the gas flow rate of the main air pump (4) and the water pumping volume of the peristaltic pump (10) according to the required droplet diameter; connect the branch air pump (26) to the corresponding gas cylinder according to the requirements; start the main air pump (4) and drive the air chamber to move to the atomization hole with the corresponding inclination on the outer wall of the atomizing tube (23) through the moving module (1); S2, the plasma power supply simultaneously supplies power to the high-voltage electrode in the primary atomization module (3) and the high-voltage electrode in the secondary atomization module (5); at this time, the peristaltic pump (10) is started to pump a metered amount of water in, and completes primary atomization and charging in the primary atomization module (3) to generate a negatively charged spray with larger droplets; S3, the negatively charged spray enters the secondary atomization module (5), the branch air pump (26) pumps the working gas into the secondary atomization module (5), the branch air flows through the air chamber and enters the atomization tube (23) from the atomization hole, shearing the large droplet spray and performing secondary atomization to form a finer spray; at the same time, the plasma generation module (7) ionizes the working gas, generating a large amount of plasma in the cavity area between the high voltage electrode and the atomization tube (23) to form a plasma spray; S4, the plasma spray carries a positive charge under the action of high voltage electricity. Driven by the high-speed airflow, the finer spray after being charged is ejected. After passing through the grounded diffuser (6), it is further attracted and diffused by the diffuser (6) to complete the three-stage atomization and form a fine spray.

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