High-throughput, high-efficiency, multimodal plasma-activated liquid preparation apparatus and use thereof in food sterilization

Abstract

A high-throughput, high-efficiency, multimodal plasma-activated liquid preparation apparatus and a use thereof in food sterilization. The apparatus comprises a generator system (2), a gas supply system (3), a water tank (1), and hybrid plasma reactors (5-1) (5-2). The hybrid plasma reactors (5-1) (5-2) are disposed in the water tank (1) and each comprise a quartz dielectric tube (19), a stainless steel rod grounding electrode (23), a first high-voltage electrode (17), and a second high-voltage electrode (16), wherein the stainless steel rod grounding electrode (23), the first high-voltage electrode (17), and the second high-voltage electrode (16) are fixed inside the quartz dielectric tube (19); the first high-voltage electrode (17) is a metal tube and sleeved outside the stainless steel rod grounding electrode (23), and the stainless steel rod grounding electrode (23) is located at the center of the first high-voltage electrode (17); the inner surface of the first high-voltage electrode (17) is provided with a dielectric layer; and the second high-voltage electrode (16) is arranged below the first high-voltage electrode (17) and sleeved outside the stainless steel rod grounding electrode (23), and the stainless steel rod grounding electrode (23) is located at the center of the second high-voltage electrode (16). The apparatus increases the variety and concentration of reactive species in the plasma-activated liquid, has broad-spectrum antibacterial activity, is simple, energy-saving and scalable, and is applicable to various food sterilization scenarios.

Description

A high-throughput, high-efficiency, multimodal plasma active liquid preparation device and its application in food sterilization. Technical Field

[0001] This invention belongs to the field of plasma sterilization, and specifically relates to a high-throughput, high-efficiency, multi-modal plasma active liquid preparation device and its application in food sterilization. Background Technology

[0002] Atmospheric pressure cryogenic plasma and its derivative form—plasma-activated solutions—possess strong bactericidal capabilities and hold promise as green agents for eliminating pathogens. Plasma-activated solutions are generated through the interaction of atmospheric pressure cryogenic plasma with a liquid medium, produced by direct plasma discharge in water or plasma discharge on the water surface. The biochemical activity of plasma-activated solutions is related to the concentration of highly reactive oxygen / nitrogen substances in the water, such as hydrogen peroxide, hydroxyl radicals, and pernitrite. The synergistic effect of these reactive substances and low pH plays a crucial role in oxidative stress in bacterial cells and damage to intracellular DNA.

[0003] However, there are still several technical problems in the process of plasma-activated solutions moving from the laboratory to industrial applications: (1) the preparation scale of plasma-activated solutions is small and the efficiency is low; (2) the plasma source required for the preparation method of plasma-activated solutions is large and the energy consumption is high; (3) the reactive substances generated by the interaction between plasma and water have poor loading and particle activity. Summary of the Invention

[0004] To overcome the aforementioned shortcomings and deficiencies of the prior art, the present invention aims to provide a high-throughput, high-efficiency, multi-modal plasma activated liquid preparation device. It introduces two discharge schemes: dielectric barrier discharge and sliding arc discharge, thereby increasing the types and concentrations of active ingredients in the plasma activated liquid, enabling high-level food sterilization applications. It has spectral antibacterial properties, effectively removing harmful bacteria from the surfaces of food, food packaging materials, and processing equipment. Furthermore, the device for large-scale preparation of plasma activated liquid is simple in structure, energy-saving, and scalable, making it suitable for various application scenarios.

[0005] Another objective of this invention is to provide the application of the above-mentioned high-throughput, high-efficiency, multimodal plasma active liquid preparation device in food sterilization.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention provides a high-throughput, high-efficiency, multimodal plasma active liquid preparation device, comprising a power supply, a gas supply system, a water tank, and at least one mixed plasma reactor; the mixed plasma reactor is located inside the water tank;

[0008] The hybrid plasma reactor includes a dielectric tube, a rod-shaped grounding electrode, a first high-voltage electrode, and a second high-voltage electrode; the rod-shaped grounding electrode, the first high-voltage electrode, and the second high-voltage electrode are fixed inside the dielectric tube.

[0009] The first high-voltage electrode is a metal tube, which is sleeved on the outside of the rod-shaped grounding electrode, and the rod-shaped grounding electrode is located at the center of the first high-voltage electrode; the inner surface of the first high-voltage electrode is provided with a dielectric layer;

[0010] The second high-voltage electrode is located below the first high-voltage electrode and is sleeved on the outside of the rod-shaped grounding electrode, with the rod-shaped grounding electrode located at the center of the second high-voltage electrode;

[0011] The working gas in the gas supply system enters the medium tube from the air inlet at the top of the medium tube, generating dielectric barrier discharge plasma between the first high-voltage electrode and the rod-shaped grounding electrode; and generating sliding arc discharge plasma between the second high-voltage electrode and the rod-shaped grounding electrode; the dielectric barrier discharge plasma and the sliding arc discharge plasma form a mixed plasma and disperse it from the air outlet at the bottom of the medium tube into the liquid in the water tank to obtain plasma activation liquid.

[0012] Preferably, the working gas enters the medium tube at a flow rate of 5-15 L / min.

[0013] Preferably, the second high-voltage electrode has a spiral structure, with its radius increasing from top to bottom.

[0014] Preferably, the second high-voltage electrode is welded to the lower end of the first high-voltage electrode.

[0015] Preferably, the air outlet below the medium tube is provided with multiple microporous aerators; the microporous aerators are provided with Pall rings on the outside.

[0016] Preferably, the liquid in the water tank contains a surfactant; the mixed plasma forms bubbles with a particle size of 50nm-1μm in the liquid; the surfactant is fatty alcohol polyoxyethylene ether, polyethylene glycol fatty acid ester, or polyvinyl alcohol.

[0017] Preferably, the dielectric layer is borosilicate and covers the inner surface of the first high-voltage electrode.

[0018] Preferably, there are two mixed plasma reactors, one of which is connected to the positive terminal of a power source and the other is connected to the negative terminal of a power source.

[0019] Preferably, the high-throughput, high-efficiency, multimodal plasma active liquid preparation apparatus further includes a humidification device for humidifying the working gas. Preferably, the apparatus for large-scale preparation of plasma active liquid also includes a solar plasma generator system, specifically comprising a foldable solar panel power generation system, a plasma power supply, and a high-voltage transformer, which can utilize the power supply or solar power to drive the hybrid plasma generation system.

[0020] Preferably, the outer layer of the dielectric tube is further provided with a heat sink, which is in close contact with the outer layer of the quartz dielectric tube.

[0021] Preferably, the grounding electrode lead of the high-throughput, high-efficiency, multimodal plasma active liquid preparation device needs to be installed below the liquid surface, and can be installed at the bottom or side of the water tank or suspended in the water.

[0022] Preferably, the second high-voltage electrode can also employ other structures to form a sliding arc discharge jet mode, generating a sliding arc discharge through vortex airflow. Specifically, the sliding arc discharge jet mode utilizes a vortex airflow generator to create vortex motion in the plasma airflow inside the reactor, thereby generating a dynamic sliding arc discharge between the high-voltage electrode and the ground electrode. Through this sliding arc discharge jet mode, the hybrid plasma reactor can adapt to different water treatment needs and can flexibly adjust the plasma generation method without significantly altering the existing structure, achieving a more efficient water treatment effect.

[0023] Preferably, the plasma power source of the present invention can provide up to 10-80 kV (V p-p The system provides high-voltage pulses with a repetitive pulse frequency of 100-3000Hz. The gas supply system can provide working gas with a flow rate of 5-15L / min. Two discharge modes can be switched or coexisted through different voltage or gas flow ranges.

[0024] Preferably, the working gas can be a mixture of different gases or a single gas. The working gas is humidified by a water-washing gas source and then pumped into the mixed plasma generation system.

[0025] Another embodiment of the present invention provides a high-throughput, high-efficiency, multimodal plasma active liquid preparation device, including a power supply system, an air inlet system, a liquid reaction container, and a mixed plasma generator. The power supply system is used to supply power to the mixed plasma generator, and the mixed plasma generator is used to convert the working gas provided by the air inlet system into mixed plasma and inject it into the liquid in the liquid reaction container.

[0026] The hybrid plasma generator includes a device housing and a first discharge unit, a second discharge unit, and a microbubble injection unit disposed within the device housing.

[0027] The first discharge unit includes an insulating dielectric shell, an axially arranged induction electrode, and an outer electrode sleeved on the insulating dielectric shell. A first gas channel is provided between the insulating dielectric shell and the induction electrode. The first gas channel is connected to the gas inlet system. The first discharge unit is used to perform dielectric barrier discharge treatment on the working gas in the first gas channel to form dielectric barrier discharge plasma.

[0028] The second discharge unit includes a sliding arc anode and a cylindrical cathode. The sliding arc anode is located below the induction electrode and is electrically connected to the induction electrode. A second gas channel is provided between the sliding arc anode and the cylindrical cathode. The second gas channel is connected to the first gas channel. The second discharge unit is used to perform sliding arc discharge treatment on the working gas after it has been processed by the first discharge unit to form a sliding arc discharge plasma.

[0029] The power system includes a first high-voltage power supply, a second high-voltage power supply, and a control unit. The control unit is used to control the connection status of the first high-voltage power supply, the second high-voltage power supply, the first discharge unit, and the second discharge unit to form a dielectric barrier discharge working mode, a sliding arc discharge working mode, and a hybrid discharge working mode.

[0030] The microbubble injection unit is located at the bottom of the hybrid plasma generator and is immersed in the liquid inside the liquid reaction vessel. The hybrid plasma generated by the hybrid plasma generator is injected into the liquid in the liquid reaction vessel through the microbubble injection unit.

[0031] In the dielectric barrier discharge working mode, the external electrode of the first discharge unit is connected to the positive terminal of the first high-voltage power supply, and the induction electrode of the first discharge unit is connected to the negative terminal of the first high-voltage power supply, so as to form a dielectric barrier discharge channel between the external electrode and the induction electrode. The dielectric barrier discharge working mode is suitable for low viscosity and low conductivity liquid food matrix (such as juice, drinking water, etc.), forming a stable non-thermal plasma discharge, mainly generating reactive oxygen species, and ensuring high-throughput continuous sterilization.

[0032] In the sliding arc discharge working mode, the sliding arc anode of the second discharge unit is connected to the positive terminal of the second high-voltage power supply, and the cylindrical cathode of the second discharge unit is connected to the negative terminal of the second high-voltage power supply, so as to form a sliding arc discharge channel between the sliding arc anode and the cylindrical cathode. The sliding arc discharge working mode is suitable for liquid food matrices with high viscosity or high protein content (such as milk and dairy beverages). High-energy discharge generates nitrogen- and oxygen-rich active species, which enhances sterilization efficiency while maintaining the sensory quality of the food.

[0033] In the hybrid discharge working mode, the external electrode of the first discharge unit is connected to the positive terminal of the first high-voltage power supply, and the cylindrical cathode of the second discharge unit is connected to the negative terminal of the first high-voltage power supply. The sensing electrode of the first discharge unit remains electrically suspended. Under the action of the high-frequency high voltage of the external electrode, the sensing electrode generates induced charges, thereby forming a high-potential region on the surface of the sensing electrode. This triggers a sliding arc discharge between the cylindrical cathode and the sliding arc anode, while maintaining the existence of dielectric barrier discharge between the external electrode and the sensing electrode. This achieves a multi-mechanism synergistic discharge by coupling dielectric barrier discharge and sliding arc discharge. The hybrid discharge working mode is suitable for complex liquid food matrices or foods that require rapid sterilization (such as mixed beverages, nutrient solutions, etc.). It also utilizes the coupling effect of dielectric barrier and sliding arc to generate multiple active species that work synergistically to achieve efficient sterilization.

[0034] Preferably, the microbubble injection unit includes a micrometer-level diffuser and a flow channel. The flow channel is connected to the second gas channel and is used to transport the mixed plasma processed by the first discharge unit and the second discharge unit to the micrometer-level diffuser. The micrometer-level diffuser is disposed at the bottom of the liquid reaction vessel. The micrometer-level diffuser is used to diffuse the mixed plasma to form fine and uniform bubbles with a diameter of less than 100 μm, forming a residence path of more than 50 mm in the liquid phase, so as to improve the mass transfer efficiency at the gas-liquid interface and enhance the dissolution and utilization of active substances.

[0035] Preferably, the hybrid plasma generator further includes a hybrid gas guide channel;

[0036] The mixed gas guiding channel is disposed between the first discharge unit and the second discharge unit. The mixed gas guiding channel is used to connect the first gas channel and the second gas channel so that the working gas provided by the air intake system flows through the first discharge unit and the second discharge unit in sequence, thereby so that the first discharge unit and the second discharge unit continuously act on the same airflow.

[0037] The mixing gas guiding channel includes a cylindrical straight-through structure, and the inner wall of the cylindrical straight-through structure is provided with guide plates to make the working gas form a vortex flow, so as to prolong the residence time of the working gas in the first discharge unit or the second discharge unit.

[0038] Preferably, the liquid reaction vessel is a closed structure, with an exhaust valve at the top, and a liquid inlet / outlet interface and a liquid level regulation system inside. The liquid reaction vessel is used to hold the liquid to be processed and can hold ≥15m³ of liquid. 3 h -1 m -2 Flux of water or liquid food matrix to be treated (such as milk, juice, beverages, etc.).

[0039] Preferably, the air intake system includes a gas source, a gas flow controller, and a gas supply conduit, for providing air, oxygen, nitrogen, or a mixture thereof to the mixed plasma generator, and ensuring a stable gas supply under high-flux conditions through high-precision flow control.

[0040] Preferably, the induction electrode of the first discharge unit is a stainless steel rod structure, the outer electrode of the first discharge unit is an annular copper strip, the insulating dielectric shell of the first discharge unit is made of quartz or ceramic material, and the discharge area between the induction electrode and the outer electrode is axially straight-through type, which can maintain stable discharge under high flow conditions and is suitable for long-term continuous operation.

[0041] Preferably, the cylindrical cathode of the second discharge unit is a cylindrical conductive shell, and the sliding arc anode of the second discharge unit is a tungsten needle electrode. The arc slides along the channel under the impetus of high-velocity gas, which enhances the uniformity of discharge and the intensity of plasma reaction, thereby significantly improving the sterilization efficiency.

[0042] Preferably, the outlet aperture of the micron-sized diffuser is between 10-100 μm, and the distance between the micron-sized diffuser and the liquid surface is greater than or equal to 50 mm, which is used to improve the mass transfer efficiency of active substances at the gas-liquid interface.

[0043] Preferably, the power system further includes a mode switching switch, and the control unit enables the hybrid plasma generator to freely switch between dielectric barrier discharge mode, sliding arc discharge mode and hybrid discharge mode according to the operation of the mode switching switch.

[0044] The application of the high-throughput, high-efficiency, multimodal plasma active liquid preparation device in food sterilization involves using the device to process liquids.

[0045] S1: Start the air intake system to supply air, oxygen, nitrogen or a mixture thereof to the mixed plasma generator. After flow control, the gas enters the first discharge unit and the second discharge unit in sequence.

[0046] S2: The discharge mode is set through the control unit. The discharge mode includes one of dielectric barrier discharge mode, sliding arc discharge mode, or mixed discharge mode. The connection relationship and output parameters between the first high-voltage power supply, the second high-voltage power supply, the first discharge unit, and the second discharge unit are set, specifically including:

[0047] In dielectric barrier discharge mode, the first high-voltage power supply is activated, the external electrode of the first discharge unit is connected to the positive terminal of the first high-voltage power supply, the induction electrode of the first discharge unit is connected to the negative terminal of the first high-voltage power supply or grounded, and the second discharge unit is de-energized.

[0048] In the sliding arc discharge mode, the second high-voltage power supply is started, the sliding arc anode of the second discharge unit is connected to the positive terminal of the second high-voltage power supply, the cylindrical cathode of the second discharge unit is connected to the negative terminal of the second high-voltage power supply or grounded, and the first discharge unit is de-energized.

[0049] In the hybrid discharge mode, the external electrode of the first discharge unit is connected to the positive terminal of the first high-voltage power supply, the induction electrode of the first discharge unit remains in a suspended state, the cylindrical cathode of the second discharge unit is connected to the negative terminal of the first high-voltage power supply, and the induction electrode forms a high potential under the excitation of the high-frequency high-voltage of the external electrode through induction, serving as the anode of the sliding arc. At the same time, dielectric barrier discharge and sliding arc discharge coexist.

[0050] In the first discharge unit, the working gas flows through the first gas channel between the insulating dielectric shell and the induction electrode, and a non-thermal plasma discharge is generated between the induction electrode and the insulating dielectric shell by means of an electric field, so as to form a dielectric barrier discharge plasma.

[0051] In the second discharge unit, the working gas continues to flow into the second gas channel between the sliding arc anode and the cylindrical cathode. Under the action of the electric field, the working gas is ignited by the sliding arc discharge under the flow drive to form a sliding arc discharge plasma.

[0052] S3: The airflow is injected into the liquid reaction vessel through the microbubble injection unit, forming uniform bubbles with a diameter of less than 100 μm. The active species are fully released along the liquid path and dissolved in the water or food liquid matrix, achieving a high efficiency of over 99.999% kill rate against a variety of microorganisms, including drug-resistant bacteria, spores, fungi, and viruses. It is also suitable for large-volume water disinfection and rapid sterilization of liquid foods, significantly improving their microbial safety while maintaining the sensory quality and nutritional components of the food.

[0053] This invention also provides the application of the above-mentioned high-throughput, high-efficiency, multimodal plasma active liquid preparation device in food sterilization. The plasma active liquid prepared by the device for large-scale preparation of plasma active liquid is used to disinfect Escherichia coli, mold, Staphylococcus aureus, Salmonella, Listeria monocytogenes and Clostridium botulinum in food, food packaging and food processing equipment. The sterilization method includes at least one of rinsing, spraying, soaking, wiping, dripping and coating. The materials of the food packaging and food processing equipment include at least one of quartz, metal, glass, stainless steel, plastic and paper.

[0054] The method for large-scale preparation of plasma activation liquid based on the above-mentioned high-throughput, high-efficiency, multimodal plasma activation liquid preparation device includes the following processing steps:

[0055] S1: Pass the aqueous solution to be treated into the water tank and add surfactant to the aqueous solution;

[0056] S2: Turn on the gas supply system to introduce the humidified working gas into the mixed plasma reactor, and then turn on the solar plasma generator system. The mixed plasma activation gas is generated in the mixed plasma reactor at the same time.

[0057] S3: The mixed plasma reaches the microporous aerator at the bottom of the quartz tube medium tube with the airflow, and the mixed plasma activation gas forms ultra-fine nanobubbles through the micropores and disperses into the liquid flow.

[0058] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0059] (1) The high-throughput, high-efficiency, multi-mode plasma active liquid preparation device of the present invention introduces two discharge schemes: dielectric barrier discharge and sliding arc discharge. The dielectric barrier discharge region focuses on generating highly loaded active oxygen substances, while the sliding arc discharge region focuses on generating highly active active nitrogen substances. Furthermore, the solubility of the mixed plasma active gas generated by the two in water is greatly improved, and a large number of high-valence nitrogen oxides that play a key role in sterilization are generated, thereby achieving high-level food sterilization applications and exhibiting spectral antibacterial properties.

[0060] (2) The high-throughput, high-efficiency, multi-modal plasma active liquid preparation device of the present invention implements a dual-reactor configuration (one connected to the positive terminal and the other connected to the negative terminal) in an AC loop, which greatly reduces the energy loss of the negative electrode (unused micro-discharge) in a single-reactor configuration and significantly improves the generation of high-valence nitrogen oxide species and energy efficiency.

[0061] (3) The high-throughput, high-efficiency, multi-modal plasma activated liquid preparation device of the present invention integrates plasma discharge with bubbles. By utilizing plasma bubble technology and bubble dynamics control (Pall ring) design, it provides a large surface area for gas-liquid interaction and improves mass transfer and residence time, greatly enhancing the efficiency of plasma activation. In addition, the addition of surfactants improves the particle size of ultrafine bubbles, further improving the efficiency of plasma activation, thereby enabling the large-scale preparation of plasma activated liquid.

[0062] (4) The high-throughput, high-efficiency, multi-modal plasma active liquid preparation device of the present invention can achieve the switching or coexistence of two discharge modes through different voltage or gas flow ranges, and can activate various different liquid media (deionized water, physiological saline, cell culture medium or artificial seawater), showing great potential applications in microbial disinfection in various scenarios (seawater aquaculture, medical treatment, cell and tissue engineering).

[0063] (5) In the high-throughput, high-efficiency, multi-modal plasma active liquid preparation device of the present invention, the solar plasma generator system has a hybrid power supply mode of solar energy and traditional power supply, which has the advantages of low carbon, environmental protection, economy and energy saving. It is suitable for areas with power shortage and outdoor environments, and has significant advantages in remote areas or emergency situations. Attached Figure Description

[0064] Figure 1 is a schematic diagram of the high-throughput, high-efficiency, multimodal plasma active liquid preparation device of the present invention.

[0065] Figure 2 is a schematic diagram of the second high-voltage electrode, the first high-voltage electrode, and the stainless steel rod grounding electrode in the high-throughput, high-efficiency, multimodal plasma active liquid preparation device of the present invention.

[0066] Figure 3 shows the bactericidal effect of different plasma activation liquid volumes (10L, 15L, 20L and 30L) on Escherichia coli in Example 1 of the present invention.

[0067] Figure 4 shows the bactericidal effect of the mixed plasma activation liquid in Example 2 of the present invention on different common foodborne pathogens (Escherichia coli, mold, Staphylococcus aureus, Salmonella, Listeria monocytogenes and Clostridium botulinum) on the surface of food.

[0068] Figure 5 shows the bactericidal effect of the mixed plasma activation liquid in Example 3 of the present invention on Escherichia coli on the surface of food packaging and processing equipment made of different materials (quartz, metal, glass, stainless steel, plastic and paper).

[0069] Figure 6 is a comparison of the concentrations of five typical gaseous reactants in the mixed plasma activation liquid large-scale preparation equipment of Example 1 and Comparative Examples 1-2 of the present invention with those in other different comparative examples.

[0070] Figure 7 is a comparison of the bactericidal effects of the mixed plasma activation liquid prepared in Example 1, Comparative Examples 1-4 and Example 4 of the present invention on Escherichia coli.

[0071] Figure 8 is a schematic diagram of a high-throughput, high-efficiency, multimodal plasma active liquid preparation device provided in another embodiment of the present invention;

[0072] Figure 9 is a schematic diagram of the internal structure of a high-throughput, high-efficiency, multimodal plasma active liquid preparation device provided in another embodiment of the present invention;

[0073] Figure 10 is a perspective view of a high-throughput, high-efficiency, multimodal plasma active liquid preparation apparatus provided in another embodiment of the present invention;

[0074] Figure 11 is a front view of a high-throughput, high-efficiency, multimodal plasma active liquid preparation apparatus provided in another embodiment of the present invention;

[0075] Figure 12 is a side view of a high-throughput, high-efficiency, multimodal plasma active liquid preparation apparatus provided in another embodiment of the present invention;

[0076] Figure 13 is a schematic diagram of the electrical connections of the high-throughput, high-efficiency, multimodal plasma active liquid preparation device shown in Figure 8;

[0077] Figure 14 shows the sterilization results of a test liquid (milk) using the high-throughput, high-efficiency, multimodal plasma active liquid preparation device provided by the present invention, according to another embodiment of the present invention.

[0078] Figure 15 shows the stability of high-throughput continuous disinfection during a long period (15 days) using the high-throughput, high-efficiency, multimodal plasma active liquid preparation device provided by the present invention, according to another embodiment of the present invention.

[0079] Reference numerals: 1. Water tank; 2. Solar plasma generator system; 3. Gas supply system; 4. Grounding electrode lead; 5-1. First mixed plasma reactor; 5-2. Second mixed plasma reactor; 6. Water inlet; 7. Water outlet; 8. Foldable solar panel power generation system; 9. Plasma power supply; 10. High-voltage transformer; 11. Gas source; 12. Gas pump; 13. Mixing tank; 14. Flow controller; 15. Switch valve; 16. Second high-voltage electrode; 17. First high-voltage electrode; 18. Radiator; 19. Quartz dielectric tube; 20. Microporous aerator; 21. Pall ring; 22. Gas inlet; 23. Stainless steel rod connector. 31. Ground electrode; 32. Gas inlet; 33. Device housing; 34. First discharge unit; 35. Insulating dielectric shell; 36. Induction electrode; 37. External electrode; 38. Second discharge unit; 39. Sliding arc anode; 30. Cylindrical cathode; 310. Mixing gas guide channel; 311. First connector; 312. Second connector; 313. Third connector; 314. Microbubble injection unit; 315. Liquid reaction vessel; 300. Three-mode coupled mixed plasma sterilization device; 330. Power supply system; 320. Gas intake system; 340. Mixed plasma generator; 331. First high-voltage power supply; 332. Second high-voltage power supply; 333. Control unit. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0081] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0082] The terms "including," "have," etc., used in this article are all open-ended, meaning they include but are not limited to.

[0083] Example 1

[0084] Referring to Figures 1 and 2, the high-throughput, high-efficiency, multimodal plasma active liquid preparation device of the present invention includes a water tank 1, a solar plasma generator system 2, a gas supply system 3, a grounding electrode lead 4, a mixed plasma reaction 5-1, and a mixed plasma reaction 5-2. The water tank 1 is used to hold the aqueous solution to be treated and is equipped with a water inlet 6 and a water outlet 7. The solar plasma generator system 2 includes a foldable solar panel power generation system 8, a plasma power supply 9, and a high-voltage transformer 10, which can use the power supply or solar power to drive the mixed plasma generation system 5. The gas supply system 3 includes a gas source 11, a gas pump 12, a mixing tank 13, a flow controller 14, and a switching valve 15. The gas source 11 provides working gas, which enters the mixing tank 13 through a gas supply pipe, and then supplies working gas with a certain pressure and flow rate to the mixed plasma reaction 5-1 and the mixed plasma reaction 5-2 through the flow controller 14. The grounding electrode lead 4 needs to be installed below the liquid surface and can be installed at the bottom, side, or suspended in the water.

[0085] Hybrid plasma reactors 5-1 and 5-2 have identical structures and are connected to the positive and negative electrodes of plasma power supply 9, respectively. The hybrid plasma reactor includes a quartz dielectric tube 19, a second high-voltage electrode 16, a first high-voltage electrode 17, a heat sink 18, a stainless steel rod grounding electrode 23, a microporous aerator 20, and a Pall ring 21. The second high-voltage electrode 16, the first high-voltage electrode 17, and the stainless steel rod grounding electrode 23 are fixed inside the quartz dielectric tube 19, with the second high-voltage electrode 16 welded to the lower end of the first high-voltage electrode 17. The first high-voltage electrode 17 is a metal tube fitted over the stainless steel rod grounding electrode 23, which is located at the center of the first high-voltage electrode 17. A dielectric layer, made of borosilicate, covers the inner surface of the first high-voltage electrode 17. The inner and outer layers of the quartz dielectric tube 19 are covered with insulators, and a gas inlet 22 is installed at the upper end. Multiple microporous aerators 20 are evenly distributed around the bottom of the quartz dielectric tube 19. Pall rings 21 can be placed outside the microporous aerators 20 as packing material. The heat sink 18 is tightly attached to the outer layer of the quartz dielectric tube 19 to ensure that the temperature generated by the plasma discharge does not affect the normal operation of the mixed plasma reactor.

[0086] The working gas enters the quartz dielectric tube through the inlet at the top, generating dielectric barrier discharge plasma between the first high-voltage electrode 17 and the stainless steel grounding electrode 23; and generating sliding arc discharge plasma between the second high-voltage electrode 16 and the stainless steel grounding electrode 23. The dielectric barrier discharge plasma and the sliding arc discharge plasma form a mixed plasma, which is dispersed into the water in the tank through the outlet at the bottom of the dielectric tube. The water can be deionized water, physiological saline, cell culture medium, or artificial seawater. A surfactant is added to the water, causing the plasma gas to form ultrafine nanobubbles in the surfactant-containing liquid. The ultrafine nanobubbles have a particle size of 50 nm to 1 μm. In this embodiment, the surfactant can be fatty alcohol polyoxyethylene ether (such as surfactant AI-600), polyethylene glycol fatty acid ester (such as the Tween series), polyvinyl alcohol (PVA), etc. These nonionic surfactants are chemically stable, have low pH sensitivity, and are suitable for various aquatic environments. In addition, these surfactants can significantly reduce surface tension and promote the formation of ultrafine nanobubbles.

[0087] In this embodiment, the working gas can be a mixture of different gases or a single gas. The working gas is humidified by a water-washing gas source and then pumped into the mixed plasma reaction 5-1 and the mixed plasma reaction 5-2.

[0088] In this embodiment, the plasma power source 9 is capable of providing up to 10-80 kV (V p-p The gas supply system 3 provides working gas at a flow rate of 5-15 L / min, and the high-voltage pulse frequency is 100-3000 Hz. Different voltage or gas flow ranges allow for switching or coexistence of two discharge modes. Specifically, the voltage range for the single dielectric barrier discharge mode is 10-30 kV (V). p-p The frequency is 100-500Hz, and the gas flow rate is 5-10L / min; while the voltage range of the independent sliding arc discharge mode is 20-40kV (V). p-p The frequency is 500-3000Hz, and the gas flow rate is 10-15L / min. If both discharge modes need to coexist, the voltage can be controlled at 20-30kV (V). p-p The frequency is controlled at 300-1000Hz, and the gas flow rate is controlled at 8-12L / min.

[0089] Single Escherichia coli colonies were inoculated into Luria-Bertani broth containing 3% NaCl at 37°C and incubated at 37°C for 24 hours, resulting in a bacterial concentration of approximately 1.0 × 10⁻⁶. 8CFU / mL. Take 10.0 mL of the cultured E. coli suspension, centrifuge at 5000 rpm for 10 min, and resuspend in pre-prepared aqueous solutions (10 L, 15 L, 20 L, and 30 L) to achieve a final concentration of 1.0 × 10⁻⁶ CFU / mL. 6 CFU / mL was used for subsequent water microbial disinfection experiments.

[0090] The prepared bacterial suspension was selected as the test water and treated using a device for large-scale preparation of plasma-activated solution. The treatment steps are as follows:

[0091] S1: Different volumes (10L, 15L, 20L and 30L) of the aqueous solution to be treated are introduced into the water tank through the water inlet, and surfactants are added to the aqueous solution to be treated;

[0092] S2: Turn on the air supply system and introduce humidified compressed air at a flow rate of 10L / min into the mixed plasma reactor. Then turn on the solar plasma generator system to generate mixed plasma for 1 minute in the first and second mixed plasma reactors under the conditions of discharge voltage of 30kV, excitation frequency of 1000Hz, and ultrafine nanobubble particle size of 150nm.

[0093] S3: The mixed plasma reaches the microporous aerator at the bottom of the quartz tube medium tube with the airflow, and the mixed plasma activation gas forms ultra-fine nanobubbles through the micropores and disperses into the liquid flow.

[0094] Bacterial colony counts were determined using the standard plating method. Figure 3 shows that this large-scale preparation equipment for mixed plasma activation fluid can efficiently generate effective mixed plasma activation fluid within a short discharge time (1 min), thereby reducing E. coli colonies by at least 6 logarithmic orders. Furthermore, this large-scale preparation equipment can improve the energy efficiency of mixed plasma activation fluid while increasing the liquid volume (from 10 L to 30 L). Even with an aqueous solution volume of 30 L, a mixed plasma activation fluid reducing E. coli colonies by 5.2 logarithmic orders can still be prepared within 1 min. This is because industrial applications require the production of larger quantities of effective plasma activation fluid while minimizing energy consumption.

[0095] Example 2

[0096] The high-throughput, high-efficiency, multimodal plasma active liquid preparation device of Example 1 was used to kill bacteria in food.

[0097] The preparation process of the mixed plasma activation solution is as follows:

[0098] S1: The aqueous solution to be treated is introduced into the water tank through the water inlet, and a surfactant is added to the aqueous solution to be treated;

[0099] S2: Turn on the air supply system and introduce humidified compressed air at a flow rate of 10L / min into the mixed plasma reactor. Then turn on the solar plasma generator system and generate mixed plasma in the first and second mixed plasma reactors at a discharge voltage of 50kV, an excitation frequency of 1000Hz, and an ultrafine nanobubble particle size of 150nm for 1min to obtain a mixed plasma activation liquid.

[0100] The mixed plasma activation solution prepared in this embodiment was applied by spraying onto colonies inoculated with different bacterial strains (bacterial concentration approximately 1.0 × 10⁻⁶). 6 The test results (CFU / mL) on food surfaces are shown in Figure 4. Figure 4 shows that the six most common foodborne pathogens in food sterilization applications—Escherichia coli, mold, Staphylococcus aureus, Salmonella, Listeria monocytogenes, and Clostridium botulinum—were completely inactivated. Furthermore, complete inactivation can be achieved by any of the methods (rinsing, spraying, soaking, wiping, dripping, and coating), which also means that this invention is adaptable to different food processing scenarios (such as large-scale production lines, small-scale manual operations, and retail packaging).

[0101] Example 3

[0102] The high-throughput, high-efficiency, multimodal plasma active liquid preparation device of Example 1 was used to kill bacteria in food.

[0103] The preparation process of the mixed plasma activation solution is as follows:

[0104] S1: The aqueous solution to be treated is introduced into the water tank through the water inlet, and a surfactant is added to the aqueous solution to be treated;

[0105] S2: Turn on the air supply system and introduce humidified compressed air at a flow rate of 10L / min into the mixed plasma reactor. Then turn on the solar plasma generator system and generate mixed plasma in the first and second mixed plasma reactors at a discharge voltage of 50kV, an excitation frequency of 1000Hz, and an ultrafine nanobubble particle size of 150nm for 1min to obtain a mixed plasma activation liquid.

[0106] The mixed plasma activation solution prepared in this embodiment was applied by spraying onto bacteria inoculated with Escherichia coli (bacterial concentration approximately 1.0 × 10⁻⁶). 6Figure 4 shows the test results (CFU / mL) on the surfaces of different food packaging materials and processing equipment (quartz, metal, glass, stainless steel, plastic, and paper). Figure 4 shows that all six materials achieved good sterilization efficiency against E. coli on their surfaces. While the sterilization efficiency varied slightly among the materials due to differences in surface properties, reactivity, and interaction with plasma, overall, all met the sterilization requirements for food packaging materials and processing equipment surfaces.

[0107] Comparative Example 1

[0108] A 20L bacterial suspension was selected as the test water. The apparatus for preparing the mixed plasma activation solution was the same as in Example 1, except that the spiral electrode at the lower end of the high-voltage electrode of the mixed plasma reactor was removed, while maintaining a dual-reactor configuration within an AC circuit (one connected to the positive terminal and the other to the negative terminal). The bacterial suspension was treated with dielectric barrier discharge plasma for 1 minute at a discharge voltage of 30kV, an excitation frequency of 500Hz, and an ultrafine nanobubble particle size of 100nm, using compressed air at a flow rate of 5L / min as the working gas.

[0109] Comparative Example 2

[0110] A 20L bacterial suspension was selected as the test water. The apparatus for preparing the mixed plasma activation solution was the same as in Example 1, except that the first high-voltage electrode of the mixed plasma reactor was removed, while maintaining a dual-reactor configuration within an AC circuit (one connected to the positive terminal and the other to the negative terminal). The bacterial suspension was treated with sliding arc discharge plasma for 1 min at a discharge voltage of 40kV, an excitation frequency of 2000Hz, and an ultrafine nanobubble particle size of 200nm, using compressed air at a flow rate of 15L / min as the working gas.

[0111] Comparative Example 3

[0112] A 20L bacterial suspension was selected as the test water. Compared to Example 1, the apparatus for preparing the mixed plasma activation solution was modified by removing the spiral electrode at the lower end of the high-voltage electrode in the mixed plasma reactor and using a single mixed plasma reactor. This was achieved by connecting the negative electrode to the grounding electrode of the stainless steel rod in the plasma bubble reactor. The bacterial suspension was treated with dielectric barrier discharge plasma for 1 minute at a discharge voltage of 30kV, an excitation frequency of 500Hz, and an ultrafine nanobubble particle size of 100nm, using compressed air at a flow rate of 5L / min as the working gas.

[0113] Comparative Example 4

[0114] A 20L bacterial suspension was selected as the test water. The apparatus for preparing the mixed plasma activation solution was the same as in Example 1, except that the first high-voltage electrode of the mixed plasma reactor was removed, and a single plasma bubble reactor configuration was used. This was achieved by connecting the negative electrode to the grounding electrode of a stainless steel rod within the plasma bubble reactor. The bacterial suspension was treated with sliding arc discharge plasma for 1 minute at a discharge voltage of 40kV, an excitation frequency of 2000Hz, and an ultrafine nanobubble particle size of 200nm, using compressed air at a flow rate of 15L / min as the working gas.

[0115] Example 4

[0116] A 20L bacterial suspension was selected as the test water. The same large-scale preparation equipment for the mixed plasma activation solution as in Example 1 was used, except that the Pall ring in the mixed plasma generation system was removed. The bacterial suspension was treated with mixed plasma for 1 min under the conditions of a discharge voltage of 30kV, an excitation frequency of 1000Hz, an ultrafine nanobubble particle size of 150nm, and a flow rate of 10L / min using compressed air as the working gas.

[0117] Figure 6 shows the concentrations of five typical gaseous reactants in the mixed plasma activation liquid prepared by the large-scale preparation equipment of the mixed plasma activation liquid in Example 1 and Comparative Examples 1-2 of the present invention. It is noteworthy that O3, NO, and NO2 have very low solubility; therefore, neither the dielectric barrier discharge mode nor the sliding arc discharge mode of air plasma can effectively activate water. The Henry's law constant of NO2 is only 1.2 × 10⁻⁶. -4 MPa -1 The Henry's law coefficients for O3 and NO are even lower. In contrast, the main discharge product of the mixed plasma in Example 1 of this invention is high-valence NO. x (such as N2O5 and NO3), therefore their activation efficiency in water may be much higher. This is because high-valence nitrogen oxides are easily soluble in water through reaction absorption, and their oxidation reactivity is also higher than that of NO and NO2, which is positively correlated with the bactericidal effect.

[0118] Figure 7 shows the inactivation efficiency of the mixed plasma activation solution large-scale preparation equipment in Examples 1, 1-4, and 4 of the present invention against Escherichia coli, compared with other different comparative examples. In comparison, the mixed plasma activation solution large-scale preparation equipment in Example 1 of the present invention has better sterilization efficiency, and implementing a dual-reactor configuration results in lower energy consumption.

[0119] Referring to Figure 8, another embodiment of the present invention provides a high-throughput, high-efficiency, multimodal plasma active liquid preparation apparatus 300. The high-throughput, high-efficiency, multimodal plasma active liquid preparation apparatus 300 includes a power supply system 330, an air intake system 320, a liquid reaction vessel 315, and a mixed plasma generator 340. The power supply system 330 supplies power to the mixed plasma generator 340. The mixed plasma generator 340 converts the working gas provided by the air intake system 320 into mixed plasma and injects it into the liquid in the liquid reaction vessel 315. In this embodiment, the mixed plasma generator 340 has a gas inlet 31. The air intake system 320 is connected to the gas inlet 31 of the mixed plasma generator 340 to provide working gas to the mixed plasma generator 340.

[0120] Please refer to Figures 9 to 12. The hybrid plasma generator 340 includes a device housing 32 and a first discharge unit 33 and a second discharge unit 37 disposed within the device housing 32. The hybrid plasma generator 340 also includes a microbubble injection unit 314 disposed at its bottom.

[0121] The first discharge unit 33 includes an insulating dielectric shell 34, an axially arranged induction electrode 35, and an outer electrode 36 sleeved on the insulating dielectric shell 34. A first gas channel L1 is provided between the insulating dielectric shell 34 and the induction electrode 35. The first gas channel L1 is connected to the gas intake system 320. The first discharge unit 33 is used to perform dielectric barrier discharge treatment on the working gas in the first gas channel L1 to form dielectric barrier discharge plasma.

[0122] The second discharge unit 37 includes a sliding arc anode 38 and a cylindrical cathode 39. The sliding arc anode 38 is located below and electrically connected to the induction electrode 35. A second gas channel L2 is provided between the sliding arc anode 38 and the cylindrical cathode 39. The second gas channel L2 is connected to the first gas channel L1. The second discharge unit 37 is used to perform sliding arc discharge treatment on the working gas processed by the first discharge unit 33 to form a sliding arc discharge plasma.

[0123] The microbubble injection unit 314 is disposed at the bottom of the mixed plasma generator 340 and immersed in the liquid inside the liquid reaction container 315. The mixed plasma generated by the mixed plasma generator 340 is injected into the liquid in the liquid reaction container 315 through the microbubble injection unit 314.

[0124] Please refer to Figure 13. The power system 330 includes a first high-voltage power supply 331, a second high-voltage power supply 332, and a control unit 333. The control unit 333 is used to control the connection state of the first high-voltage power supply 331, the second high-voltage power supply 332, the first discharge unit 33, and the second discharge unit 37 to form a dielectric barrier discharge working mode, a sliding arc discharge working mode, and a mixed discharge working mode.

[0125] In the dielectric barrier discharge operating mode, the external electrode 36 of the first discharge unit 33 is connected to the positive terminal of the first high-voltage power supply 331. The sensing electrode 35 of the first discharge unit 3 is connected to the negative terminal of the first high-voltage power supply 331, so as to form a dielectric barrier discharge channel between the external electrode 36 and the sensing electrode 35.

[0126] In the sliding arc discharge working mode, the sliding arc anode 38 of the second discharge unit 37 is connected to the positive terminal of the second high voltage power supply 332, and the cylindrical cathode 39 of the second discharge unit 37 is connected to the negative terminal of the second high voltage power supply 332, so as to form a sliding arc discharge channel between the sliding arc anode 38 and the cylindrical cathode 39.

[0127] In the hybrid discharge operating mode, the external electrode 36 of the first discharge unit 33 is connected to the positive terminal of the first high-voltage power supply 331. The cylindrical cathode 39 of the second discharge unit 37 is connected to the negative terminal of the first high-voltage power supply 331. The sensing electrode 35 of the first discharge unit 33 remains electrically suspended. Under the action of the high-frequency high voltage of the external electrode 36, the sensing electrode 35 generates induced charges, thereby forming a high-potential region on the surface of the sensing electrode 35. This triggers a sliding arc discharge between the cylindrical cathode 39 and the sliding arc anode 38, while maintaining a dielectric barrier discharge between the external electrode 36 and the sensing electrode 35, thus achieving a multi-mechanism synergistic discharge coupling dielectric barrier discharge and sliding arc discharge.

[0128] Specifically, this invention sequentially arranges a first discharge unit (dielectric barrier discharge mode) and a second discharge unit (sliding arc discharge mode) within a single device housing, forming an integrated plasma generation and injection system. Each discharge unit is sequentially connected via a mixed gas guiding channel, constructing a coupled discharge system that enables continuous excitation of the same gas flow, thereby achieving high-level plasma sterilization applications.

[0129] Furthermore, this invention proposes a multi-mode control mechanism based on power switching and induction electrode control, which allows for the selection of three discharge modes under different circuit connection methods: dielectric barrier discharge mode, sliding arc discharge mode, and hybrid discharge mode that combines two discharge modes.

[0130] Meanwhile, by arranging the first discharge module and the second discharge module in series, the present invention forms a multi-discharge mode reaction system of front and rear stages, enabling the active species generated by different types of discharge to be sequentially superimposed; at the same time, in the hybrid discharge mode, the induction electrode of the first unit can also serve as the sliding arc anode, thereby breaking the functional module boundary, realizing spatial reconfigurable energy reuse and functional compounding, and significantly improving the system integration and operational stability.

[0131] In this embodiment, the microbubble injection unit 314 includes a micrometer-scale diffuser and a flow channel. The flow channel is connected to the second gas channel L2 and is used to transport the mixed plasma processed by the first discharge unit 33 and the second discharge unit 37 to the micrometer-scale diffuser. The micrometer-scale diffuser is disposed at the bottom of the liquid reaction vessel 315. The micrometer-scale diffuser is used to diffuse the mixed plasma to form bubbles with a diameter of less than 100 μm, which are then released from bottom to top into the liquid in the liquid reaction vessel 315.

[0132] In this embodiment, the present invention introduces microbubble mass transfer technology to improve the conversion efficiency of discharge products and gas-liquid interface dynamics to the microscale level, so that the active components can enter the liquid phase more quickly to react, thereby forming a highly active, highly stable, and broadly applicable plasma activation liquid with multiple functions such as efficient sterilization, removal of pollutants, and promotion of plant growth.

[0133] Specifically, the device housing 32 is internally provided with a first discharge unit 33, a second discharge unit 37, and a microbubble injection unit 314, which are connected sequentially along the gas inlet direction for sequentially introducing gas into the discharge area and finally injecting it into the liquid. As needed, the device housing 32 is made of a high-heat-resistant insulating material, preferably ceramic or polytetrafluoroethylene, to ensure its high-pressure resistance and gas corrosion resistance.

[0134] In one embodiment, the air intake system 320 includes a gas source, a gas flow controller, and a gas supply conduit for providing air, oxygen, nitrogen, or a mixture thereof to the mixed plasma generator. Specifically, the air intake system 320 may have at least two independent, switchable gas inlets (one located above the first discharge unit 33 and one located to the left of the second discharge unit 37), respectively connected to an air source, an oxygen cylinder, a nitrogen cylinder, and a rare gas (such as helium or argon) source. Each inlet is equipped with a precision gas flow control valve and a check valve structure for multi-gas combination and mixing. The first discharge unit 3 preferably uses air or high-purity oxygen as the discharge medium. The second discharge unit 7 is suitable for using air, nitrogen, or a rare gas (helium or argon).

[0135] In one embodiment, the sensing electrode 35 of the first discharge unit 33 is a stainless steel rod-shaped structure. The outer electrode 36 of the first discharge unit 33 is an annular copper strip. The insulating dielectric shell 34 of the first discharge unit 33 is made of quartz or ceramic material. The discharge region between the sensing electrode 35 and the outer electrode 36 is axially continuous.

[0136] Specifically, the first discharge unit 33 is a dielectric barrier discharge module. The first discharge unit 33 includes an insulating dielectric shell 34, an axially arranged induction electrode 35, and an outer electrode 36 sleeved on the shell. A gas channel is provided between the insulating dielectric shell 34 and the induction electrode 35, forming a dielectric barrier discharge reaction zone. This reaction zone is located at the upper part of the device body, and the air intake duct of the air intake system 320 is connected to its air intake port to excite air or oxygen to generate a mixture rich in O3, ·OH, etc. 1 The first plasma flow containing reactive oxygen species such as O2.

[0137] Understandably, in this embodiment, the discharge structure is an axially straight-through design, which can form a stable and uniform surface discharge area, and has the characteristics of low temperature and high energy efficiency, making it suitable for continuous gas discharge.

[0138] In one embodiment, the cylindrical cathode 39 of the second discharge unit 37 is a cylindrical conductive shell. The sliding arc anode 38 of the second discharge unit 37 is a tungsten needle electrode. The sliding arc generated by the cylindrical cathode 39 and the sliding arc anode 38 slides within the discharge channel under the propulsion of the working gas flow to enhance the reaction efficiency of the non-equilibrium plasma and the gas.

[0139] Specifically, the second discharge unit 37 is a sliding arc discharge module. The second discharge unit 37 is located below the first discharge unit 33. The sliding arc discharge region of the second discharge unit 37 includes a gap channel between the tungsten needle-shaped sliding arc anode 38 and the cylindrical cathode 39 below the induction electrode 35. The input gas is driven by airflow to generate a sliding arc, forming a series-coupled reaction region, further generating a second plasma gas rich in high-energy nitrogen oxides such as NO, NO3, and N2O5. Specifically, the second discharge unit 37 is entirely encapsulated within a ceramic insulating shell, and is equipped with an inlet and an outlet to achieve flow field control and insulation safety.

[0140] In one embodiment, the hybrid plasma generator 340 further includes a hybrid gas guide channel 310. The hybrid gas guide channel 310 is disposed between the first discharge unit 33 and the second discharge unit 37. The hybrid gas guide channel 310 connects the first gas channel 33 and the second gas channel 37, so that the working gas provided by the air intake system 320 flows sequentially through the first discharge unit 33 and the second discharge unit 37, thereby causing the first discharge unit 33 and the second discharge unit 37 to continuously act on the same gas flow.

[0141] Specifically, the mixing gas guide channel 310 includes a cylindrical straight-through structure. The inner wall of the cylindrical straight-through structure is provided with guide plates to cause the working gas to form a vortex flow, thereby prolonging the residence time of the working gas in the first discharge unit or the second discharge unit.

[0142] In this embodiment, the mixing gas guiding channel 310 is disposed between the first discharge unit 33 and the second discharge unit 37, forming a gas flow channel and ensuring that the discharge areas are sequentially connected, so that the two-stage discharge continuously acts on the same gas flow. Specifically, the mixing gas guiding channel has a cylindrical straight-through structure, and the inner wall is provided with guide plates to form vortex flow, prolonging the residence time of the gas in the discharge area. The mixing gas guiding channel 310 is disposed between the first discharge unit 33 and the second discharge unit 37, mainly serving to guide flow, equalize pressure, and prevent backflow.

[0143] In this embodiment, the power supply system 330 includes a first high-voltage power supply 331 and a second high-voltage power supply 332. The first high-voltage power supply 331 supplies power to the dielectric barrier discharge unit. The second high-voltage power supply 332 supplies power to the sliding arc discharge unit. The sensing electrode 35 switches roles according to the power connection status in different discharge modes. The power supply system 330 can adjust its output power to adapt to the load requirements of different discharge modes, and is equipped with an automatic overcurrent and overvoltage protection mechanism to ensure operational safety.

[0144] As needed, the power supply system 330 can also include a drive circuit system. The drive circuit system includes a set of voltage output terminals and multiple switching ports. The drive circuit system is connected to the plasma discharge unit via the power supply system. The voltage output terminals are electrically connected to the input terminals of the electrode assembly to supply power to the discharge electrodes. The switching ports are connected to the control module for switching on and off according to the set operating mode. Simultaneously, the drive circuit system is also connected to a detection and feedback unit to monitor the output voltage, current, and discharge status in real time, thereby achieving stable control of the discharge process. The following three operating modes can be selected by switching the circuit connection method:

[0145] In dielectric barrier discharge mode, the external electrode 36 is connected to the high voltage AC power of the first high voltage power supply 331 through the first connector 311, and the induction electrode 35 is connected to the low voltage end of the first high voltage power supply 331 or grounded through the second connector 312, in order to form a stable dielectric barrier discharge structure.

[0146] In the sliding arc mode, the induction electrode 35 is directly connected to the second high-voltage power supply 332 through the second connector 312 as the anode, and the cylindrical cathode 39 is connected to the low-voltage end of the second high-voltage power supply 332 through the third connector 313 as the cathode, forming a sliding arc channel.

[0147] In the hybrid discharge mode, only the external electrode 36 is connected to the high-voltage AC power supply 331 via the first connector 311. The induction electrode 35 remains electrically suspended, and the high-frequency high-voltage voltage on the external electrode 36 excites induced charges, forming a high-potential region on its surface. This triggers a sliding arc discharge between the cylindrical cathode 39 and the sliding arc anode 38, while maintaining dielectric barrier discharge, thus achieving a multi-mechanism synergistic discharge coupling between non-thermal plasma and the sliding arc.

[0148] It is understood that this embodiment achieves adaptive operation of three modes through power switching and sensing electrode control, which not only improves functional flexibility but also reduces structural redundancy and significantly improves system integration and energy efficiency.

[0149] As needed, the power system 330 also includes a mode switching switch. The control unit 333, based on the operation of the mode switching switch, freely switches the hybrid plasma generator between dielectric barrier discharge mode, sliding arc discharge mode, and hybrid discharge mode. Specifically, the control unit 333 includes a mode switching switch, a voltage adjustment knob, and an LCD monitoring unit, allowing users to switch operating modes and adjust output frequency, voltage, and power via an external interface.

[0150] In this embodiment, the control module of the present invention provides the ability to freely switch between three discharge modes. Parameters such as voltage, frequency, and power can be adjusted externally in real time. It also supports modular, portable, and industrial-scale deployment to adapt to disinfection tasks under different water qualities, different types of microorganisms, and pollution levels. It can be used in scenarios such as drinking water purification, medical device cleaning, and food surface sterilization.

[0151] In this embodiment, the liquid reaction container 315 is a sealed structure. An exhaust valve is provided at the top of the liquid reaction container 315. The interior of the liquid reaction container 315 includes a liquid inlet / outlet port and a liquid level regulation system. The liquid reaction container is used to hold the liquid to be processed. The mixed plasma in the microbubble injection unit 314 is released into the liquid in the liquid reaction container 315 to form a three-mode coupled plasma activation liquid. Specifically, the liquid reaction container 315 is a pressure-resistant transparent reaction vessel with an exhaust valve at the top and an internal liquid level controller and overflow protection device.

[0152] Depending on the requirements, the outlet aperture of the micron-sized diffuser is between 10-100 μm, and the distance between the micron-sized diffuser and the liquid surface is greater than or equal to 50 mm. The active gas passes through this diffuser to form fine and uniform bubbles in the liquid, creating a residence path greater than 50 mm in the liquid phase, thereby improving the gas-liquid interface mass transfer efficiency and enhancing the dissolution and utilization of active substances. In this embodiment, the microbubble injection unit 14 is equipped with a micron-sized diffuser and a flow guiding channel. The micron-sized diffuser is located at the bottom of the liquid container, and the active gas diffuses to form bubbles with a diameter of 10 μm, which are released into the liquid from bottom to top. Specifically, the micron-sized diffuser uses ceramic sintering material or a 316L stainless steel microporous plate with a pore size of 10-50 μm.

[0153] It is understood that this embodiment significantly increases the gas-liquid phase contact area through a high-density microbubble diffusion structure, thereby enhancing the conversion efficiency of active species in the plasma gas to the liquid phase.

[0154] Another embodiment of the present invention provides a liquid processing method. The liquid processing method utilizes the high-throughput, high-efficiency, multimodal plasma active liquid preparation apparatus 300 as described in any of the above embodiments to perform liquid processing, specifically including the following steps:

[0155] S1: The air intake system 320 is activated to supply air, oxygen, nitrogen, or a mixture thereof to the mixed plasma generator 340. The gas, after flow control, sequentially enters the first discharge unit 33 and the second discharge unit 37. In this embodiment, the gas flow rate is controlled to 10 L / min before sequentially entering the first discharge unit 33 and the second discharge unit 37.

[0156] S2: Based on the properties of the liquid to be treated, the discharge mode is set by the control unit 333. The discharge mode includes one of a dielectric barrier discharge mode, a sliding arc discharge mode, or a mixed discharge mode. The connection relationships and output parameters between the first high-voltage power supply 331, the second high-voltage power supply 332, the first discharge unit 33, and the second discharge unit 37 are also set. Specifically, this includes:

[0157] In dielectric barrier discharge mode, the first high-voltage power supply 331 is activated, the external electrode 36 of the first discharge unit 33 is connected to the positive terminal of the first high-voltage power supply 331, the sensing electrode 35 of the first discharge unit 33 is connected to the negative terminal of the first high-voltage power supply 331 or grounded, and the second discharge unit 37 is de-energized.

[0158] In the sliding arc discharge mode, the second high-voltage power supply 332 is started, the sliding arc anode 38 of the second discharge unit 37 is connected to the positive terminal of the second high-voltage power supply 332, the cylindrical cathode 39 of the second discharge unit 37 is connected to the negative terminal of the second high-voltage power supply 332 or grounded, and the first discharge unit 33 is de-energized.

[0159] In the hybrid discharge mode, the external electrode 36 of the first discharge unit 33 is connected to the positive terminal of the first high-voltage power supply 331, the induction electrode 35 of the first discharge unit 33 remains in a suspended state, the cylindrical cathode 39 of the second discharge unit 37 is connected to the negative terminal of the first high-voltage power supply 331, and the induction electrode 35 forms a high potential under the excitation of the high-frequency high-voltage voltage of the external electrode 36 through induction, serving as the anode of the sliding arc. At the same time, dielectric barrier discharge and sliding arc discharge coexist.

[0160] Specifically, in one embodiment, the discharge mode is set by the control unit 333, the hybrid discharge mode is selected on the control panel, and the output power of the power system is set to 80W, the power output voltage is 20kV, and the frequency is 10kHz. Only the external electrode 36 is connected to the high-voltage power supply, and the induction electrode 35 remains in a suspended state. Its surface forms a high potential under high-frequency excitation through induction, which serves as the anode of the sliding arc. At the same time, dielectric barrier discharge and sliding arc discharge coexist.

[0161] In the first discharge unit 33, the working gas flows through the first gas channel L1 between the insulating dielectric shell 34 and the induction electrode 35. A non-thermal plasma discharge is generated between the induction electrode 35 and the insulating dielectric shell 34 by means of an electric field, forming a dielectric barrier discharge plasma. In this step, the gas flows through a dielectric barrier discharge reaction zone provided with an axial induction electrode and an annular outer electrode. A high AC voltage is applied to the outer electrode, and the induction electrode is connected to the low-voltage end of the power supply or grounded. A non-thermal plasma discharge is generated between the electrode and the insulating dielectric by means of an electric field, mainly generating reactive oxygen species (such as O3, ·OH, etc.). 1 The first type of active particles, mainly O2, form the first stage of plasma flow.

[0162] In the second discharge unit 37, the working gas continues to flow into the second gas channel L2 between the sliding arc anode 38 and the cylindrical cathode 39. Under the action of the electric field, the working gas is ignited by the sliding arc discharge driven by the flow to form a sliding arc discharge plasma. In this step, the gas continues to flow into the second discharge unit, i.e., the sliding arc discharge region. This region is provided with a narrow slit channel between the anode tip downstream of the induction electrode and the cylindrical cathode. The gas is ignited by the sliding arc discharge driven by the flow, generating a second type of plasma gas rich in nitrogen and oxygen active species (such as NO, N2O5, NO3, etc.). In the same gas channel, dielectric barrier discharge and sliding arc coupling occur simultaneously, forming a composite discharge mechanism, superimposed to generate a mixed plasma gas flow with synergistic effects of multiple active species.

[0163] S3: The airflow is injected into the liquid reaction container 315 through the microbubble injection unit, allowing the active species to fully dissolve and undergo an oxidation-reduction reaction with the water to obtain a plasma-activated liquid for disinfection and sterilization. In this step, uniform bubbles with a diameter of less than 100 μm are formed, fully releasing the active species along the liquid path and dissolving them in the water or food liquid matrix. This enables highly efficient killing of various microorganisms, including drug-resistant bacteria, spores, fungi, and viruses (killing rate can reach over 99.999%), and is suitable for large-volume water disinfection and rapid sterilization of liquid foods, significantly improving the microbial safety of food while maintaining its sensory quality and nutritional components.

[0164] In this embodiment, the high-throughput, high-efficiency, multimodal plasma active liquid preparation device of the present invention is applied to a continuous flow sterilization scenario for food, particularly for the processing of high-risk dairy products (milk), to verify its high-throughput advantage in a continuous water flow operation mode. As shown in Figure 14, this embodiment adds a continuous flow inlet and outlet pipeline system and a peristaltic pump drive device to the liquid reaction vessel 15, allowing milk to pass through the reaction chamber at a constant flow rate in a closed loop. Specifically, milk is continuously injected into the reaction vessel from the inlet via a peristaltic pump at a flow rate of 500 mL / min. After being fully contacted with the mixed plasma gas flow through the bottom microbubble injection module, it flows out from the outlet and is collected, achieving dynamic flow sterilization treatment.

[0165] Under the experimental conditions, the gas flow rate was set to 10 L / min, the power supply was 80 W, the voltage was 20 kV, and the frequency was 10 kHz. The device operated in a mixed discharge mode, generating gases rich in O3, ·OH, and other compounds. 1 A composite plasma gas flow containing multiple reactive species such as O2, NO3, and N2O5 is generated. The gas is injected into flowing milk through a microbubble diffuser (10 μm aperture), forming a bubble cluster with a diameter of about 15 μm. The bubble stays in the liquid channel for about 30 seconds, achieving efficient gas-liquid mass transfer and dissolution of reactive species.

[0166] The milk samples were inoculated with common high-risk food-related microorganisms, including: methicillin-resistant Staphylococcus aureus, Salmonella typhimurium, Listeria monocytogenes, Bacillus subtilis, Candida albicans, and bacteriophage MS2, with an initial contamination concentration of 1×10⁻⁶. 6 CFU / mL or PFU / mL. Experimental results showed that under continuous treatment for 1 min (approximately 500 mL milk flow rate), the inactivation rate of each indicator strain and model virus exceeded 99.999% (>6-log), with spore-forming bacteria and fungi also being significantly reduced, demonstrating strong and broad-spectrum bactericidal performance.

[0167] Further high-throughput verification results (Figure 15) show that the device can continuously process about 30L of milk within 15 hours, with the sterilization efficiency remaining stable and without significant decay. Furthermore, the sensory quality and nutritional composition of the food do not change significantly, verifying the applicability and industrial scale-up potential of the device in complex high-viscosity liquids such as dairy products.

[0168] In summary, this embodiment demonstrates that the high-throughput, high-efficiency, multi-modal plasma active liquid preparation device of the present invention can not only be used for static batch processing, but also achieve high-throughput and high-efficiency sterilization and disinfection of liquid foods such as milk in continuous flow mode, and has the application prospect of being deployed in food processing production lines.

[0169] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A high throughput, high efficiency, multi-modal plasma activated liquid production apparatus, characterized in that, It includes a power supply, a gas supply system, a water tank, and at least one mixed plasma reactor; the mixed plasma reactor is located inside the water tank; The hybrid plasma reactor includes a dielectric tube, a rod-shaped grounding electrode, a first high-voltage electrode, and a second high-voltage electrode; the rod-shaped grounding electrode, the first high-voltage electrode, and the second high-voltage electrode are fixed inside the dielectric tube. The first high-voltage electrode is a metal tube, which is sleeved on the outside of the rod-shaped grounding electrode, and the rod-shaped grounding electrode is located at the center of the first high-voltage electrode; the inner surface of the first high-voltage electrode is provided with a dielectric layer; The second high-voltage electrode is located below the first high-voltage electrode and is sleeved on the outside of the rod-shaped grounding electrode, with the rod-shaped grounding electrode located at the center of the second high-voltage electrode; The working gas in the gas supply system enters the medium tube from the air inlet at the top of the medium tube, generating dielectric barrier discharge plasma between the first high-voltage electrode and the rod-shaped grounding electrode. A sliding arc discharge plasma is generated between the second high-voltage electrode and the rod-shaped grounding electrode. The dielectric barrier discharge plasma and the sliding arc discharge plasma form a mixed plasma, which is dispersed from the outlet below the dielectric tube into the liquid in the water tank to obtain the plasma activation liquid.

2. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 1, wherein, The working gas enters the medium tube at a flow rate of 5-15 L / min.

3. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 1, wherein, The second high-voltage electrode has a spiral structure, and its radius increases from top to bottom.

4. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 3, wherein, The second high-voltage electrode is welded to the lower end of the first high-voltage electrode.

5. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 1, wherein, The air outlet below the medium tube is equipped with multiple microporous aerators; the microporous aerators are equipped with Pall rings on their exterior.

6. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 5, wherein, The liquid in the water tank contains a surfactant; the mixed plasma forms bubbles with a particle size of 50nm-1μm in the liquid; the surfactant is fatty alcohol polyoxyethylene ether, polyethylene glycol fatty acid ester or polyvinyl alcohol.

7. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 1, wherein, The dielectric layer is borosilicate and covers the inner surface of the first high-voltage electrode.

8. A high throughput, high efficiency, multi-modal plasma activated liquid production apparatus, characterized in that, It includes a power supply system, an air intake system, a liquid reaction vessel, and a mixed plasma generator. The power supply system is used to supply power to the mixed plasma generator, and the mixed plasma generator is used to convert the working gas provided by the air intake system into mixed plasma and inject it into the liquid in the liquid reaction vessel. The hybrid plasma generator includes a device housing and a first discharge unit and a second discharge unit disposed within the device housing; the hybrid plasma generator also includes a microbubble injection unit disposed at its bottom; The first discharge unit includes an insulating dielectric shell, an axially arranged induction electrode, and an outer electrode sleeved on the insulating dielectric shell. A first gas channel is provided between the insulating dielectric shell and the induction electrode. The first gas channel is connected to the gas inlet system. The first discharge unit is used to perform dielectric barrier discharge treatment on the working gas in the first gas channel to form dielectric barrier discharge plasma. The second discharge unit includes a sliding arc anode and a cylindrical cathode. The sliding arc anode is located below the induction electrode and is electrically connected to the induction electrode. A second gas channel is provided between the sliding arc anode and the cylindrical cathode. The second gas channel is connected to the first gas channel. The second discharge unit is used to perform sliding arc discharge treatment on the working gas after it has been processed by the first discharge unit to form a sliding arc discharge plasma. The power system includes a first high-voltage power supply, a second high-voltage power supply, and a control unit. The control unit is used to control the connection status of the first high-voltage power supply, the second high-voltage power supply, the first discharge unit, and the second discharge unit to form a dielectric barrier discharge working mode, a sliding arc discharge working mode, and a hybrid discharge working mode. The microbubble injection unit is immersed in the liquid inside the liquid reaction vessel, and the mixed plasma generated by the mixed plasma generator is injected into the liquid in the liquid reaction vessel through the microbubble injection unit; In the dielectric barrier discharge working mode, the external electrode of the first discharge unit is connected to the positive terminal of the first high voltage power supply, and the induction electrode of the first discharge unit is connected to the negative terminal of the first high voltage power supply, so as to form a dielectric barrier discharge channel between the external electrode and the induction electrode. In the sliding arc discharge working mode, the sliding arc anode of the second discharge unit is connected to the positive terminal of the second high voltage power supply, and the cylindrical cathode of the second discharge unit is connected to the negative terminal of the second high voltage power supply, so as to form a sliding arc discharge channel between the sliding arc anode and the cylindrical cathode. In the hybrid discharge operating mode, the external electrode of the first discharge unit is connected to the positive terminal of the first high-voltage power supply, and the cylindrical cathode of the second discharge unit is connected to the negative terminal of the first high-voltage power supply. The sensing electrode of the first discharge unit remains electrically suspended. Under the action of the high-frequency high voltage of the external electrode, the sensing electrode generates induced charge, thereby forming a high potential region on the surface of the sensing electrode. This triggers a sliding arc discharge between the cylindrical cathode and the sliding arc anode, while maintaining the existence of dielectric barrier discharge between the external electrode and the sensing electrode. This achieves multi-mechanism synergistic discharge by coupling dielectric barrier discharge and sliding arc discharge.

9. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 8, wherein, The microbubble injection unit includes a micrometer-level diffuser and a flow channel. The flow channel is connected to the second gas channel and is used to transport the mixed plasma processed by the first discharge unit and the second discharge unit to the micrometer-level diffuser. The micrometer-level diffuser is located at the bottom of the liquid reaction vessel. The micrometer-level diffuser is used to diffuse the mixed plasma to form uniform bubbles with a diameter of less than 100 μm, forming a residence path of more than 50 mm in the liquid phase, so as to improve the mass transfer efficiency at the gas-liquid interface and enhance the dissolution and utilization of active substances.

10. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 8, wherein, The hybrid plasma generator also includes a hybrid gas guide channel; The mixed gas guiding channel is disposed between the first discharge unit and the second discharge unit. The mixed gas guiding channel is used to connect the first gas channel and the second gas channel so that the working gas provided by the air intake system flows through the first discharge unit and the second discharge unit in sequence, thereby so that the first discharge unit and the second discharge unit continuously act on the same airflow. The mixing gas guiding channel includes a cylindrical straight-through structure, and the inner wall of the cylindrical straight-through structure is provided with guide plates to make the working gas form a vortex flow, so as to prolong the residence time of the working gas in the first discharge unit or the second discharge unit.

11. The high-throughput, high-efficiency, multi-modal, plasma-activated liquid production device of claim 8, wherein, The liquid reaction container is a closed structure. The top of the liquid reaction container is equipped with an exhaust valve. The interior of the liquid reaction container is equipped with a liquid inlet / outlet interface and a liquid level adjustment system. The liquid reaction container is used to hold the liquid to be processed.

12. The high-throughput, high-efficiency, multi-modal, plasma-activated liquid preparation device of claim 8, wherein, The air intake system includes an air source, a gas flow controller, and a gas supply duct, for providing air, oxygen, nitrogen, or a mixture thereof and delivering them to the mixed plasma generator.

13. The high-throughput, high-efficiency, multi-modal, plasma-activated liquid production device of claim 8, wherein, The induction electrode of the first discharge unit is a stainless steel rod structure, the outer electrode of the first discharge unit is an annular copper strip, the insulating dielectric shell of the first discharge unit is made of quartz or ceramic material, and the discharge area between the induction electrode and the outer electrode is axially straight.

14. The high flux, high efficiency, multi-modal, plasma-activated liquid production device of claim 8, wherein, The cylindrical cathode of the second discharge unit is a cylindrical conductive shell, and the sliding arc anode of the second discharge unit is a tungsten needle electrode. The sliding arc generated by the cylindrical cathode and the sliding arc anode slides along the channel under the push of the working gas to enhance the reaction efficiency of the non-equilibrium plasma and the gas.

15. Use of the high flux, high efficiency, multi-modal plasma active liquid producing device according to any one of claims 1-14 for food sterilization, characterized in that, The plasma activation liquid prepared by the aforementioned large-scale plasma activation liquid preparation device is used to disinfect Escherichia coli, mold, Staphylococcus aureus, Salmonella, Listeria monocytogenes and Clostridium botulinum in food, food packaging and food processing equipment; the disinfecting method includes at least one of rinsing, spraying, soaking, wiping, dripping and coating; the material of the food packaging and food processing equipment includes at least one of quartz, metal, glass, stainless steel, plastic and paper.

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