Purification apparatus and method based on discharge-excited catalytic microdroplets

Abstract

The application provides a purification device and method based on discharge excitation catalytic microdroplets, and belongs to the field of gas purification. The device comprises a shell, a mixing mechanism, a microdroplet generating mechanism and an electric field generator. The shell has a purification cavity, the bottom of which is provided with a storage area for storing atomized liquid and catalyst, and the purification cavity is provided with a gas inlet and a gas outlet. The mixing mechanism is used for uniformly mixing the atomized liquid and the catalyst; the microdroplet generating mechanism is used for converting the atomized liquid mixed with the catalyst into microdroplets and releasing them; and the electric field generator comprises a first electrode and a second electrode, and a first electric field area is formed between the two. The microdroplets are transported to the first electric field area by airflow, migrate and adhere to the inner wall of the shell and / or the surface of the electrode under the action of the electric field force, and the catalyst-containing liquid formed after adhesion flows back along the wall surface to the storage area. The application drives the microdroplets to migrate and adhere and flow back through the electric field, realizes the recycling of the catalyst, and improves the gas purification efficiency and continuous operation capacity.

Description

Technical Field

[0001] This application belongs to the field of gas purification, and more specifically, it relates to a purification device and method based on discharge-excited catalytic microdroplets. Background Technology

[0002] Current air purification technologies mostly employ filtration or adsorption, which are effective against particulate matter, but their ability to continuously purify volatile organic compounds (VOCs) and microorganisms is limited. In recent years, high-voltage discharge technology has been applied to air purification, using a strong electric field between electrodes to excite active species, thereby achieving pollutant degradation and sterilization. However, these devices typically operate at high voltages, consume a lot of energy, and easily produce byproducts such as ozone and nitrogen oxides. Furthermore, the efficiency of the reaction interface is insufficient, making it difficult to achieve efficient synergistic removal of VOCs and microorganisms. Therefore, current gas purification methods generally suffer from poor purification effects. Summary of the Invention

[0003] The purpose of this application is to provide a purification device and method based on discharge-excited catalytic microdroplets to solve the technical problem that the gas purification methods in the prior art generally have poor purification effects.

[0004] To achieve the above objectives, the technical solution adopted in this application is: to provide a purification device based on discharge-excited catalytic microdroplets, the purification device comprising: The housing has a purification chamber for purifying the gas, and the bottom of the purification chamber is provided with a storage area for storing the atomizing liquid and the catalyst. The purification chamber has a gas inlet and a gas outlet. Mixing mechanism; The mixing mechanism is located in the storage area and is used to uniformly mix the atomizing liquid and the catalyst in the storage area; Microdroplet generating mechanism; The microdroplet generating mechanism is located inside the purification chamber and is used to convert the atomized liquid mixed with catalyst into microdroplets; An electric field generator; the electric field generator includes a first electrode and a second electrode, which are spaced apart to form a first electric field region between the first electrode and the second electrode; the first electric field region is located between the gas inlet and the gas outlet; The purification device based on discharge-excited catalytic microdroplets is configured as follows: The microdroplets released by the microdroplet generating mechanism are transported to the first electric field region by airflow, and migrate and attach to the inner wall of the shell and / or the surface of the electrode under the action of electric field force in the first electric field region. The inner wall of the shell and / or the surface of the electrode are connected to the storage area so that the catalyst-containing liquid formed after attachment flows back to the storage area along the wall surface.

[0005] Optionally, the inner wall of the housing forms a first electrode, and the second electrode is located inside the purification chamber, such that the first electrode surrounds the second electrode.

[0006] Optionally, the first electrode is a cylindrical electrode extending along the axial direction of the purification chamber, and the second electrode is a rod-shaped electrode arranged along the axial direction of the purification chamber. An electric field is formed between the first electrode and the second electrode in the radial direction of the purification chamber. The airflow direction in the purification chamber is along the axial direction of the purification chamber, the extension direction of the cylindrical electrode is consistent with the airflow direction, and the airflow direction intersects with the electric field direction.

[0007] Optionally, the second electrode is configured to be connected to the positive terminal of a high-voltage power supply, and the first electrode is grounded; the direction of the electric field between the second electrode and the first electrode is radial from the second electrode to the first electrode.

[0008] Optionally, the mixing mechanism includes an ultrasonic oscillator, which is at least partially disposed within the storage area.

[0009] Optionally, the microdroplet generating mechanism and the mixing mechanism share a liquid pump, which has a first output port and a second output port; The first output port is connected to the spraying component of the microdroplet generating mechanism, and is used to deliver the atomized liquid mixed with the catalyst to the spraying component to form microdroplets; The second output port is connected to the storage area and is used to output liquid into the storage area to impact the mixed atomized liquid and catalyst.

[0010] Optionally, the mixing mechanism includes a third electrode located on the side of the storage area away from the purification chamber; The first electrode extends to the periphery of the storage area. The first electrode and the third electrode form a second electric field region in the storage area. The third electrode is connected to an alternating circuit so that the second electric field region forms an alternating electric field.

[0011] Optionally, the purification device based on discharge-excited catalytic microdroplets also includes an auxiliary droplet capture mechanism; The auxiliary droplet capture mechanism includes a fourth electrode and a fifth electrode, which are spaced apart to form a third electric field region. The third electric field region is located downstream of the first electric field region and closer to the gas outlet than the first electric field region, in order to capture residual microdroplets.

[0012] Optionally, the auxiliary droplet capture mechanism also includes a flow guide hood, which has an arc-shaped structure. A through hole is provided in the middle of the flow guide hood to allow airflow to pass through. The through hole is centered with the fourth electrode, and the polarity of the fourth electrode is opposite to the polarity of the charge carried by the microdroplet, so as to attract the microdroplet to migrate towards the fourth electrode. The flow guide extends around the inner wall of the purification chamber, with a gap between it and the inner wall, so that the liquid adhering to the flow guide flows along the surface of the flow guide through the gap to the inner wall and back to the storage area.

[0013] Optionally, a microdroplet collector is also provided in the third electric field zone. The microdroplet collector is used to collect residual microdroplets moving in the third electric field zone. The microdroplet collector is connected to the inner wall of the purification chamber to guide the collected catalyst-containing liquid to the inner wall and return it to the storage area.

[0014] Optionally, the purification device based on discharge-excited catalytic microdroplets includes a first chamber, a second chamber, and a third chamber arranged sequentially from bottom to top; The gas inlet is located in the first compartment, and the gas outlet is located in the third compartment; The mixing mechanism and microdroplet generating mechanism are located in the first chamber, the electric field generator is located in the second chamber, and the auxiliary droplet capturing mechanism is located in the third chamber.

[0015] This application also provides a purification method based on discharge-excited catalytic microdroplets, which employs the above-mentioned purification device based on discharge-excited catalytic microdroplets.

[0016] Optionally, the purification method based on discharge-excited catalytic microdroplets includes the following steps: The atomizing liquid and catalyst are mixed evenly in the storage area; The atomized liquid containing the catalyst is converted into microdroplets and released; Microdroplets are transported to the first electric field region by airflow, where they are subjected to electric field forces to migrate and adhere to the inner wall of the shell and / or the surface of the electrode, so that the catalyst-containing liquid formed after adhesion flows back to the storage area along the wall.

[0017] Optionally, the purification method based on discharge-excited catalytic microdroplets also includes: The catalyst uses catalyst particles. The surface area of ​​a single microdroplet is determined based on the diameter of the microdroplet, and the projected coverage area of ​​a single catalyst particle on the droplet surface is determined based on the particle size of the catalyst particles. Based on the target coverage of the catalyst on the surface of the microdroplet, determine the number of catalyst particles required to adhere to the surface of a single microdroplet. Based on the ratio of catalyst particle number to microdroplet number, the volume fraction or mass concentration of catalyst in the atomizing liquid is determined to determine the amount of catalyst to be added. The catalyst is added to the atomizing fluid according to the determined amount.

[0018] The purification device based on discharge-excited catalytic microdroplets in this embodiment uses a mixing mechanism to uniformly mix the atomized liquid and catalyst in the storage area. A microdroplet generating mechanism converts the catalyst-mixed atomized liquid into micron-sized microdroplets. These microdroplets, carried by the airflow, enter the first electric field region and become charged. Under the influence of the electric field, they migrate and adhere to the inner wall of the housing and / or the electrode surface, forming a catalyst-containing liquid film. Since the inner wall of the housing and / or the electrode surface are connected to the storage area, the liquid formed after adhesion naturally flows back to the storage area along the wall, thus achieving catalyst recycling. Therefore, the microdroplets provide a large gas-liquid interface area, increasing the probability of contact between pollutants and active species; the electric field drives the droplets to actively migrate, enhancing mass transfer efficiency; the liquid film on the wall is continuously renewed, maintaining high reactivity; and the liquid reflux prevents catalyst loss with the airflow, extending the continuous operating time of the device. Simultaneously, the device can stably discharge at a lower voltage, reducing the risk of ozone and other byproduct formation, achieving efficient, low-consumption, and pollution-free gas purification. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an external schematic diagram of the purification device in the embodiments of this application; Figure 2 This is a schematic diagram of the internal structure of the purification device in one embodiment of this application; Figure 3 This is a lateral view of the electric field of the purification device in the embodiments of this application; Figure 4 This is a top-down schematic diagram of the electric field of the purification device in the embodiments of this application; Figure 5 This is a schematic diagram of the internal structure of the purification device in another embodiment of this application; Figure 6 This is a schematic diagram of the internal structure of the purification device in another embodiment of this application; Figure 7 This is an exploded view of multiple chambers of the purification device in the embodiments of this application.

[0021] Reference numerals: First chamber 1; microdroplet generating mechanism 11; mixing mechanism 12; liquid pump 110; first output port 111; jetting component 112; second output port 121; second chamber 2; second electrode 21; first electrode 22; third electrode 23; third chamber 3; flow guide 31; fourth electrode 32; fifth electrode 33; microdroplet collecting component 34; gas inlet 101; gas outlet 102; sealing ring 4. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Volatile organic compounds (VOCs) and airborne bacteria, fungi, and other microorganisms are common indoor air pollutants. VOCs are continuously released from building materials, furniture, and daily activities, while microorganisms can be transmitted through the air and affect human health. Therefore, simultaneously removing VOCs and sterilizing the air is crucial for improving indoor air quality. Current indoor air purification technologies primarily rely on filtration or adsorption, which are generally more suitable for particulate matter removal and have limited ability to continuously purify VOCs and microorganisms.

[0027] In recent years, air purification technology based on high-voltage discharge oxidation has received widespread attention. This technology typically creates a strong electrostatic field between a high-voltage electrode and a grounded electrode, exciting or ionizing components in the air such as oxygen and water molecules. This generates strong oxidizing species such as ozone, superoxide radicals, and hydroxyl radicals, thereby oxidizing and removing volatile organic compounds (VOCs) and microorganisms from the air. However, existing devices mostly employ a single high-voltage discharge method. When relying solely on the high-voltage electrostatic field, the excitation efficiency of oxygen and water molecules in the air remains limited, exhibiting a significant performance ceiling and making it difficult to achieve efficient and deep removal of VOCs and microorganisms. Furthermore, the high-voltage discharge process is prone to generating ozone byproducts, and the release of excessive ozone may pose a risk of secondary pollution, thus affecting indoor air quality and safety. Specifically, existing high-voltage dielectric barrier discharge (DBD) air purification devices typically rely on kilovolt-level discharge power supplies for operation. The high operating voltage and large energy consumption are not conducive to the miniaturization and low-energy operation of the devices. The discharge occurs directly in the bulk air, which can easily produce harmful byproducts such as ozone and nitrogen oxides. The reaction mainly occurs in the bulk gas phase space, resulting in insufficient interface utilization efficiency. The generation, migration, and utilization of active species are relatively dispersed and easily dissipated in ineffective areas. The synergistic control ability of volatile organic compound removal and microbial inactivation is limited, making it difficult to simultaneously achieve efficient degradation, rapid inactivation, and byproduct inhibition.

[0028] To further improve purification efficiency, some technologies attempt to introduce catalysts. There are two main types of catalyst loading methods: one is to coat the catalyst onto the surface of the discharge electrode or component, utilizing surface catalytic sites to enhance the reaction. However, this type of catalyst only functions at the gas-solid interface, and the diffusion and contact of active species and pollutant molecules generated by the discharge in the gas phase are limited, resulting in low catalyst utilization and easy surface deactivation due to byproducts. The other method involves dissolving the catalyst in a liquid to form a catalytic liquid, which is then atomized into microdroplets suspended in the gas, allowing the catalyst to fully contact the pollutants along with the microdroplets, thereby exerting a catalytic effect. However, in this method, the microdroplets are easily lost with the airflow during purification, leading to continuous catalyst depletion, reduced purification performance, and potential secondary pollution.

[0029] To address the aforementioned problems, this application provides a purification device based on discharge-excited catalytic microdroplets. Please refer to [link to relevant documentation]. Figure 1 and Figure 2 The purification device based on discharge-excited catalytic microdroplets includes: The housing has a purification chamber for purifying the gas, and the bottom of the purification chamber is provided with a storage area for storing the atomizing liquid and the catalyst. The purification chamber has a gas inlet 101 and a gas outlet 102. Mixing mechanism 12; The mixing mechanism 12 is disposed in the storage area and is used to uniformly mix the atomizing liquid and the catalyst in the storage area; Microdroplet generating mechanism; The microdroplet generating mechanism is used to convert atomized liquid mixed with catalyst into microdroplets; An electric field generator; the electric field generator includes a first electrode 22 and a second electrode 21, the first electrode 22 and the second electrode 21 are spaced apart to form a first electric field region between the first electrode 22 and the second electrode 21; the first electric field region is located between the gas inlet 101 and the gas outlet 102; The purification device based on discharge-excited catalytic microdroplets is configured as follows: The microdroplets released by the microdroplet generating mechanism are transported to the first electric field region by airflow, and migrate and attach to the inner wall of the shell and / or the surface of the electrode under the action of electric field force in the first electric field region. The inner wall of the shell and / or the surface of the electrode are connected to the storage area so that the catalyst-containing liquid formed after attachment flows back to the storage area along the wall surface.

[0030] The purification device based on discharge-excited catalytic microdroplets in this embodiment mainly includes a shell, a mixing mechanism 12, a microdroplet generating mechanism, and an electric field generator. The shell forms the outer contour and internal reaction space of the entire device. A purification chamber for purifying the gas is provided inside the shell, and a storage area is provided at the bottom of the purification chamber for storing the atomizing liquid and catalyst. In this embodiment, the catalyst is preferably an insoluble solid nanoparticle, such as nano-titanium dioxide, nano-zinc oxide, nano-iron oxide, or other supported catalytic particles. This type of catalyst is dispersed in the atomizing liquid in a suspended state and is insoluble in water or solvents. The purification chamber also has a gas inlet 101 and a gas outlet 102. The gas to be treated enters the purification chamber through the gas inlet 101 and is discharged through the gas outlet 102 after purification. In this embodiment, the gas inlet 101 can be located at the lower part of the purification chamber, and the gas outlet 102 can be located at the upper part of the purification chamber, so that the gas flows from bottom to top through the entire purification chamber, prolonging the contact time between the gas and the microdroplets and the electric field.

[0031] The mixing mechanism 12 is at least partially located within the storage zone to ensure uniform mixing of the atomizing liquid and the catalyst. Since the catalyst consists of insoluble solid nanoparticles, it is prone to sedimentation or stratification if left to stand for extended periods; therefore, the mixing mechanism 12 plays a crucial role. The mixing mechanism 12 continuously stirs or agitates the liquid within the storage zone to maintain the uniform dispersion of the catalyst in the atomizing liquid, thereby ensuring a stable catalyst content in the subsequently generated microdroplets. The mixing mechanism 12 can employ an ultrasonic oscillator, using ultrasound to generate cavitation effects and microjets in the liquid, resulting in uniform suspension of the catalyst particles; alternatively, it can utilize common stirring methods such as mechanical stirrers or magnetic stir bar. The microdroplet generating mechanism is located within the purification chamber, typically above or to the side of the storage zone. Its function is to convert the atomizing liquid containing the catalyst within the storage zone into micron- or submicron-sized microdroplets and release these microdroplets into the purification chamber. The microdroplet generating mechanism can employ a jet-type microdroplet generator, such as a piezoelectric atomizing nozzle or a pneumatic atomizing nozzle, or an ultrasonic atomizing plate. The atomized microdroplets are extremely small, with a single droplet diameter of, for example, around 3 micrometers. This dramatically increases the gas-liquid interface area per unit volume of liquid, which is beneficial for subsequent contact and reaction with gaseous pollutants.

[0032] The electric field generator includes a first electrode 22 and a second electrode 21, which are spaced apart to form a first electric field region in the space between them. This first electric field region is located between the gas inlet 101 and the gas outlet 102, meaning the gas to be treated must flow through this electric field region to reach the outlet from the inlet. The first electrode 22 and the second electrode 21 can be of various shapes, such as rod-shaped, cylindrical, plate-shaped, needle-shaped, or mesh-shaped. In one example of this embodiment, the first electrode 22 is directly formed on the inner wall of the housing, for example, the inner wall is made of metal or coated with a conductive layer, and the second electrode 21 is a rod-shaped electrode disposed at the center of the purification chamber. The first electrode 22 and the second electrode 21 are arranged coaxially, forming a radial electric field between them. The electric field strength of the first electric field region is sufficient to charge, polarize, and migrate passing microdroplets, and can also excite discharge to generate plasma and active species.

[0033] The device in this embodiment is configured to operate as follows: microdroplets released by the microdroplet generating mechanism are transported to the first electric field region by airflow. Because the microdroplets are extremely small, they easily move with the airflow; therefore, the direction and speed of the airflow determine the distribution of the microdroplets within the purification chamber. Upon entering the first electric field region, the microdroplets are situated in a strong electric field between the first electrode 22 and the second electrode 21. Under the influence of the electric field, the microdroplets undergo induced charging or contact charging, acquiring positive or negative charges on their surfaces. Simultaneously, the electric field exerts a directional force on the charged microdroplets, causing them to migrate towards the electrodes with opposite polarities. For example, if the first electrode 22 is grounded and the second electrode 21 is connected to a high-voltage positive electrode, then positively charged microdroplets will migrate towards the first electrode 22, i.e., the inner wall of the housing, while negatively charged microdroplets will migrate towards the second electrode 21, i.e., the central rod. In either case, the microdroplets will eventually move towards and adhere to the inner wall of the housing and / or the surface of the electrodes. After the microdroplets adhere, they gradually spread and coalesce due to surface tension and wall wettability, forming a catalyst-containing liquid film. Since the inner wall of the casing and / or the surface of the electrodes are connected to the storage area at the bottom—for example, if the wall extends continuously downwards to the storage area or a flow channel is provided—the catalyst-containing liquid formed after adhesion can naturally flow downwards along the wall under gravity, eventually returning to the storage area. This completes a full cycle from atomization, charging, migration, adhesion, coalescence, to return.

[0034] Further analysis from a principle perspective reveals that the atomizing liquid in the storage area is typically an aqueous solution uniformly mixed with insoluble solid nanocatalysts. The continuous operation of the mixing mechanism 12 ensures that the catalyst does not settle. The microdroplet generating mechanism atomizes the atomizing liquid into numerous microdroplets, which are carried upwards by the airflow into the first electric field region. In the first electric field region, the high-voltage electrostatic field between the first electrode 22 and the second electrode 21 induces charge in the microdroplets. The mechanism of induced charge is as follows: in the electric field, the free charges inside the droplet redistribute, inducing opposite charges on the side of the droplet surface closer to the high-voltage electrode and the same charges on the side farther from the high-voltage electrode; if the droplet comes into contact with or approaches the electrode, it may also acquire a net charge through contact charging. Once the droplet carries a net charge, it is subject to an electric field force. The magnitude of the electric field force is proportional to the amount of charge carried by the droplet and the electric field strength, and its direction is along the electric field lines towards the electrode of opposite polarity. For a coaxially arranged rod-cylinder electrode, the electric field is radial, and therefore the electric force is also radial, driving the droplet toward the inner wall of the shell or the central rod.

[0035] After droplets migrate and collide with the wall or electrode surface under the influence of an electric field, the wall surface, which is usually hydrophilic or has been treated to be hydrophilic, allows the droplets to spread rapidly. The continuous impact and spreading of multiple droplets gradually forms a continuous liquid film on the surface. This liquid film contains insoluble catalyst solid particles brought from the storage area, as well as water-soluble pollutants absorbed from the gas phase. Because the catalyst is a solid particle, it is trapped in the liquid film and will not be lost with liquid permeation, which is beneficial for maintaining catalytic activity over a long period. Simultaneously, the strong electric field itself and the potential micro-discharges excite oxygen and water molecules in the air, generating reactive species such as ozone, hydroxyl radicals, and superoxide radicals. Some of these reactive species react directly with volatile organic compounds in the gas phase, while others dissolve into the liquid film and interact with the catalyst solid particles. The surface of the solid catalyst provides abundant active sites, enabling it to catalyze the decomposition of ozone to produce hydroxyl radicals or directly participate in the oxidation reaction of pollutants. Therefore, the liquid film becomes a highly active reaction interface.

[0036] Polluted air containing volatile organic compounds and microorganisms enters the purification chamber through gas inlet 101 and flows upward through the first electric field zone. During this flow, pollutants in the air directly collide with and come into contact with suspended micro-droplets, being adsorbed and oxidized by the droplet surfaces. Simultaneously, as the airflow passes through the liquid film on the wall, pollutants also diffuse into the liquid film and are degraded. Microorganisms such as bacteria and fungi, under the combined influence of the strong electric field, active species (especially hydroxyl radicals), and the chemical environment within the liquid film, experience cell membrane disruption, protein and nucleic acid damage, leading to rapid inactivation. Due to the presence of the radial electric field, charged droplets continuously migrate towards the wall surface, constantly renewing the wall liquid film, preventing the accumulation of surface reaction products, and maintaining high reactivity.

[0037] The liquid adhering to the inner wall of the housing or the electrode surface contains insoluble catalyst solid particles and flows naturally downwards along the wall under gravity. Since the inner wall of the housing and / or the electrode surface are connected to the storage area, the liquid eventually returns to the storage area. This reflux process brings several beneficial effects: First, the catalyst is effectively recovered; insoluble catalyst particles that would otherwise be lost with the microdroplets carried away by the airflow are returned to the storage area through reflux, preventing a continuous decrease in catalyst concentration and extending the continuous operating time of the device after a single catalyst addition. Second, the refluxed liquid replenishes the amount of liquid carried away by atomization, keeping the liquid level in the storage area relatively stable and eliminating the need for frequent replenishment. Third, as the refluxed liquid flows down the wall, it also washes away catalyst particles or reaction products deposited on the wall surface, keeping the wall clean and facilitating subsequent droplet adhesion and liquid film renewal.

[0038] In this embodiment, micron-sized droplets provide a huge specific surface area, significantly increasing the probability of contact between pollutants and active species and catalysts. The electric field drives the charged droplets to actively migrate towards the wall surface, while the liquid film on the wall surface is continuously renewed, allowing pollutants to be rapidly adsorbed and oxidized, improving the mass transfer efficiency of traditional diffusion-based methods. The insoluble catalyst, in the form of solid particles, is dynamically dispersed with the droplets in the electric field region, forming an active liquid film on the wall surface. This avoids the problem of deactivation due to surface covering of fixed catalysts and prevents the loss of free catalyst with airflow. Due to the small-gap electrode structure, stable discharge can be formed at lower voltages, reducing power supply costs and energy consumption. The microdroplet interface promotes the decomposition of ozone into hydroxyl radicals, thereby reducing ozone emissions, and the liquid environment can also absorb some nitrogen oxides. The electric field captures and recirculates the droplets, allowing a single catalyst addition to support a much longer continuous operating time than without recirculation. Furthermore, the insoluble catalyst is less prone to agglomeration during redispersement with the recirculated liquid, resulting in good long-term operational stability. The catalyst is not released into the room with the purified gas, avoiding secondary pollution. The discharge directly generates a strong oxidant, which synergistically works with the liquid-phase catalytic environment at the microdroplet interface to simultaneously and efficiently degrade various volatile organic compounds and inactivate bacteria, fungi, and viruses. The composition of the catalytic liquid can be flexibly adjusted to suit different pollutants. The device employs a vertically layered structure, with gas flowing from bottom to top and droplets naturally refluxing, eliminating the need for an additional circulation pump. Its simple and reliable structure makes it suitable for applications such as household air purifiers and medical environments. Compared to conventional high-voltage discharge purification, this embodiment, through microdroplet generation and electric field-assisted reflux, combined with the recycling of insoluble solid catalysts, solves the problems of easy deactivation and loss of coated catalysts, as well as the low utilization rate, high byproduct rate, and difficulty in long-term continuous operation of traditional discharge interfaces. This achieves efficient, low-consumption, long-life gas purification without secondary pollution.

[0039] In some embodiments of this application, the inner wall of the housing forms a first electrode 22, and the second electrode 21 is located inside the purification chamber, such that the first electrode 22 is arranged around the second electrode 21.

[0040] In this embodiment, the inner wall of the housing is directly used as the first electrode 22. That is, the first electrode 22 is not an independent additional component, but is formed by the inner wall surface of the housing itself. For example, the housing can be made of metal, or its inner wall surface can be coated with a conductive layer, so that the inner wall is conductive and can be used as an electrode.

[0041] The second electrode 21 is located inside the purification chamber, opposite to the inner wall of the housing. With this arrangement, the first electrode 22, i.e., the inner wall of the housing, surrounds the second electrode 21, forming a spatial configuration in which the inner wall surrounds the central electrode.

[0042] Specifically, the first electrode 22 is usually cylindrical or cylindrical and extends along the axial direction of the purification chamber; the second electrode 21 can be rod-shaped, column-shaped or needle-shaped and is located near the axis of the purification chamber, so that the first electrode 22 and the second electrode 21 are coaxial or approximately coaxial, and the first electrode 22 completely surrounds the second electrode 21 in the radial direction.

[0043] A ring-shaped or radial electric field region is formed between the first electrode 22 and the second electrode 21. The direction of the electric field is approximately along the radial direction, that is, from the central second electrode 21 to the surrounding first electrodes 22, or vice versa, depending on the polarity of the applied voltage. The high uniformity of the radial electric field is beneficial for applying a stable radial force to the charged microdroplets, driving the microdroplets to migrate from the central region to the inner wall of the shell.

[0044] Since the first electrode 22, i.e., the inner wall of the shell, is itself a wall surface, when microdroplets migrate to the inner wall under the action of the electric field, they will directly adhere to the inner wall and form a liquid film. The inner wall is connected to the storage area at the bottom, so the adhered liquid can flow naturally downwards along the inner wall and return to the storage area, achieving catalyst recovery and liquid recycling. However, it should be noted that to prevent the liquid film adhering to the inner surface of the first electrode from directly contacting the first electrode 22 and causing electrolysis, gas evolution, or Joule heating, the wall surface of the first electrode 22 facing the inner side of the purification chamber is covered with a dielectric isolation layer. The dielectric isolation layer is a non-conductive dielectric material, including but not limited to polytetrafluoroethylene, ceramic, anodized layer, or inert polymer insulating coating. It electrically isolates the metal substrate of the first electrode from the liquid film and the liquid in the storage area, while allowing the electric field to couple to the liquid film and the interior of the liquid through the dielectric isolation layer, thus not changing the effect of microdroplets migrating and adhering to the first electrode under the action of the electric field, and the effect of the adhered liquid flowing back to the storage area along the wall surface. In this way, the liquid film and the reflux liquid do not come into direct contact with the metal substrate throughout the entire path of contact with the first electrode, avoiding the formation of a closed electrolytic circuit in the liquid phase due to potential difference, and ensuring that the purification device maintains a non-Radida, isothermal, and unheated working state during liquid treatment and recovery; in addition, the dielectric isolation layer can also prevent the catalyst from corroding and contaminating the electrode metal.

[0045] Furthermore, integrating the first electrode 22 with the housing reduces the need for separate electrode components, simplifies the device structure, lowers manufacturing costs, and avoids obstruction of airflow by additional electrodes. The second electrode 21 is located inside the purification chamber and can be a separate rod-shaped electrode. Its surface can also be covered with droplets. However, since the second electrode 21 is usually not directly connected to the storage area, or the liquid on it requires an additional flow guiding structure for return, this embodiment mainly relies on the first electrode 22, i.e., the inner wall of the housing, to achieve the main liquid return channel.

[0046] Please see Figure 3 and Figure 4In some embodiments of this application, the first electrode 22 is a cylindrical electrode extending along the axial direction of the purification chamber, and the second electrode 21 is a rod-shaped electrode arranged along the axial direction of the purification chamber. An electric field is formed between the first electrode 22 and the second electrode 21 along the radial direction of the purification chamber. The airflow direction in the purification chamber is along the axial direction of the purification chamber, the extension direction of the cylindrical electrode is consistent with the airflow direction, and the airflow direction intersects with the electric field direction.

[0047] In this embodiment, the first electrode 22 is a cylindrical electrode that extends along the axial direction of the purification chamber, forming a generally cylindrical conductive structure. The second electrode 21 is a rod-shaped electrode, also arranged along the axial direction of the purification chamber, typically located near the central axis of the purification chamber. Since the first electrode 22 is cylindrical and the second electrode 21 is rod-shaped, and they are arranged coaxially or substantially coaxially, the direction of the electric field formed between the first electrode 22 and the second electrode 21 is along the radial direction of the purification chamber, that is, from the central rod-shaped electrode to the outer cylindrical electrode, or vice versa, depending on the polarity of the applied voltage.

[0048] A radial electric field means that the electric force mainly acts in the horizontal direction (perpendicular to the axis). When a microdroplet enters this electric field region, it is subjected to a radial electric force, which drives the microdroplet to migrate towards the inner wall of the shell (i.e., the cylindrical electrode) or towards the central rod electrode. Since the microdroplets are usually positively or negatively charged, under the action of the radial electric field, they will move from the airflow center region towards the wall surface, thereby increasing the probability of contact with the liquid film on the wall surface, which is also beneficial for subsequent adhesion and reflux.

[0049] Meanwhile, the airflow direction within the purification chamber is set to flow axially along the purification chamber. That is, after the gas to be treated enters from the gas inlet 101, it flows along the length of the purification chamber (e.g., from bottom to top) and finally exits from the gas outlet 102. The extension direction of the cylindrical electrode is consistent with the airflow direction, both being axial. Therefore, the cylindrical electrode does not create additional obstruction to the airflow, and the airflow can smoothly pass through the internal channel enclosed by the cylindrical electrode along the axial direction.

[0050] Since the electric field is radial and the airflow is axial, these two directions are perpendicular to each other in space, i.e., they intersect. This intersecting arrangement plays a crucial role. While the microdroplets move axially with the airflow, they are also subjected to the radial electric field force. Therefore, the trajectory of the microdroplets is a synthesis of axial and radial motion. The microdroplets are both carried forward by the airflow and pushed towards the wall or central electrode by the electric field force, thus achieving a longer actual movement path and more opportunities for wall collisions within the limited length of the purification chamber. The radial electric field causes the microdroplets to continuously migrate towards the wall, while the axial airflow continuously transports the microdroplets to new electric field regions. The combination of these two forces fully utilizes the entire length of the electric field region, improving the capture efficiency and reaction contact efficiency of the microdroplets. Furthermore, the intersection of the airflow direction and the electric field direction also means that the relative motion between the microdroplets and gaseous pollutants during migration is more complex, which is beneficial for gas-liquid mass transfer and interfacial reactions.

[0051] In some embodiments of this application, the second electrode 21 is configured to be connected to the positive terminal of a high-voltage power supply, and the first electrode 22 is grounded; the electric field direction between the second electrode 21 and the first electrode 22 is radially from the second electrode 21 to the first electrode 22.

[0052] In this embodiment, the second electrode 21 is configured to be connected to the positive terminal of a high-voltage power supply, meaning the second electrode 21 is at a high potential. The first electrode 22 is grounded, meaning the potential of the first electrode 22 is zero or the reference ground potential. An electric field is formed between the second electrode 21 and the first electrode 22, and the direction of the electric field is defined as from high potential to low potential; therefore, the direction of the electric field is radial from the second electrode 21 to the first electrode 22.

[0053] The second electrode 21 is a rod-shaped electrode located in the central region of the purification chamber. The first electrode 22 is a cylindrical electrode formed by the inner wall of the shell and surrounds the second electrode 21. Therefore, the direction of the electric field is radially outward from the central rod-shaped electrode to the surrounding cylindrical electrodes.

[0054] When the microdroplet enters the first electric field region, it undergoes polarization and charging in the strong radial electric field surrounding the central rod-shaped electrode (connected to the high-voltage positive electrode). In this embodiment, the second electrode 21 is configured to be connected to the positive electrode of the high-voltage power supply. The air near it is ionized under the influence of the strong electric field, causing gas molecules to lose electrons and generate a large number of positive gas ions. These positive ions are pushed outward by the electric field pointing from the center to the outer wall, are pushed away from the second electrode 21, fill the first electric field region, and migrate towards the grounded outer wall. After the microdroplet enters with the airflow, it collides and combines with the above-mentioned positive ions, thereby acquiring a net positive charge. At the same time, the microdroplet is polarized in the radial electric field: the side closer to the rod-shaped electrode induces a negative charge, and the side farther away induces a positive charge; however, the net charge of the microdroplet is determined by the captured positive ions, so the whole microdroplet is positively charged. In an electric field pointing radially outward from the center to the outer wall, the positively charged microdroplet experiences a Coulomb force in the same direction as the electric field, i.e., from the second electrode 21 at the center outward towards the first electrode 22, thus migrating towards and attaching to the inner wall of the casing. In this embodiment, the central positive electrode and the grounded outer wall configuration ensure that the microdroplet is positively charged, repelled by the positive electrode rod, and attracted by the grounded outer wall, providing the correct and stable electric field and force direction for its migration towards the wall. In other designs, the microdroplet may be initially positively charged upon leaving the atomizing nozzle, or further charged through corona discharge, both of which contribute to the microdroplet acquiring the positive charge required for its migration towards the wall.

[0055] Grounding the first electrode 22 is for safety reasons. Grounding the inner wall of the casing prevents electric shock hazards when users touch the casing, as the casing is the external structure of the device. Grounding conducts leakage current to the earth, ensuring safe use. Simultaneously, the grounding electrode can serve as a reference potential, making the electric field distribution more stable.

[0056] The electric field points from the center to the outer wall, causing the charged microdroplets to experience an outward thrust in the radial electric field, continuously moving towards the inner wall of the shell. Upon reaching the inner wall, the microdroplets adhere to and coalesce into a liquid film, which then flows back to the storage area along the inner wall. Because the inner wall is grounded, the liquid film is also at ground potential, preventing the accumulation of excessive static electricity, which is beneficial for stable liquid flow and re-atomization.

[0057] This configuration, with a positive center electrode and a grounded outer wall, facilitates the formation of a strong electric field near the central electrode, easily inducing micro-discharge or corona discharge, and generating plasma and active species. The central electrode has a small diameter and a small radius of curvature, resulting in a concentrated electric field, which is beneficial for corona induction at lower voltages. Meanwhile, the grounded outer wall, as a large-area electrode, provides a relatively uniform electric field distribution.

[0058] In some embodiments of this application, the mixing mechanism 12 includes an ultrasonic oscillator, which is at least partially disposed within the storage area.

[0059] In this embodiment, the mixing mechanism 12 includes an ultrasonic oscillator. The ultrasonic oscillator is at least partially disposed within the storage area, that is, the vibrating end face or amplitude transformer of the ultrasonic oscillator is immersed in the atomizing liquid in the storage area, or the ultrasonic waves are transmitted to the liquid through the wall of the storage area.

[0060] When an ultrasonic oscillator operates, it generates high-frequency mechanical vibrations, typically above 20 kHz. When these high-frequency vibrations propagate through a liquid medium, they create alternating pressure changes between compressed and rarefaction zones, generating ultrasonic waves. When the intensity of the ultrasonic waves is sufficiently high, cavitation occurs in the liquid, forming tiny bubbles. These bubbles rapidly grow, oscillate, and eventually collapse under the influence of sound pressure. The collapse of these bubbles generates localized high temperatures, high pressures, and intense microjets. These microjets impact the surface of the catalyst solid particles, dispersing them from their aggregated state and suspending them uniformly in the liquid.

[0061] In this embodiment, the catalyst is made of insoluble solid nanoparticles, such as nano-titanium dioxide or nano-zinc oxide. These particles are prone to settling due to gravity or agglomerating due to van der Waals forces when left static. The ultrasonic waves generated by the ultrasonic oscillator can effectively break up the agglomeration, ensuring that the catalyst particles are uniformly dispersed in the atomizing liquid and preventing local concentrations from being too high or too low. This is crucial for ensuring that each microdroplet generated by the microdroplet generator contains a stable number of catalyst particles.

[0062] The ultrasonic oscillator is at least partially located within the storage area, ensuring that the ultrasonic energy acts directly on the liquid in the storage area, resulting in high energy transfer efficiency and significant mixing effect. Alternatively, the ultrasonic oscillator can be installed flush against the bottom or side wall of the storage area, transmitting ultrasonic waves through the wall surface to achieve the same mixing effect.

[0063] Compared to mechanical or magnetic stirring, ultrasonic oscillators offer the advantage of eliminating the need for moving stirring components within the storage area, thus avoiding shear damage to the catalyst and reducing sealing and wear issues. Furthermore, ultrasound can degas the liquid, removing dissolved gases from the atomized liquid, which is beneficial for the subsequent formation of microdroplets and the stability of the discharge process.

[0064] Please see Figure 5 In some embodiments of this application, the microdroplet generating mechanism and the mixing mechanism 12 share a liquid pump 110, which has a first output port 111 and a second output port 121. The first output port 111 is connected to the spray member 112 of the microdroplet generating mechanism and is used to deliver the atomized liquid mixed with the catalyst to the spray member 112 to form microdroplets. The second output port 121 is connected to the storage area and is used to output liquid to the storage area to impact the mixed atomized liquid and the catalyst.

[0065] In this embodiment, the microdroplet generating mechanism and the mixing mechanism 12 share a single liquid pump 110. The liquid pump 110 simultaneously supplies atomizing liquid to the microdroplet generating mechanism and provides impact agitation to the storage zone. The liquid pump 110 has two output ports. One output port is connected to the injection element 112 of the microdroplet generating mechanism, such as an atomizing nozzle or needle. The liquid pump 110 extracts the atomizing liquid mixed with the catalyst from the storage zone and delivers it to the injection element 112 through this output port. The injection element 112 converts the atomizing liquid into micron- or submicron-sized microdroplets and releases them into the purification chamber. The other output port communicates with the storage zone. The liquid pump 110 returns a portion of the liquid to the storage zone through this output port. This portion of liquid flows out at a high velocity, directly impacting the atomizing liquid and catalyst mixture in the storage zone. Due to the impact of the liquid, local turbulence and disturbance are generated in the liquid within the storage zone, thereby resuspending the catalyst solid particles settled at the bottom and achieving uniform mixing of the atomizing liquid and the catalyst.

[0066] The liquid pump 110 is an indispensable component of the microdroplet generating mechanism because the jet 112 requires a certain pressure of liquid for proper atomization. By adding an extra outlet, the liquid pump 110 can simultaneously perform the mixing function without adding an additional power component, fully utilizing the pump's delivery capacity. Compared to a separate mixing mechanism 12, this design saves space and cost. There is no need to install an ultrasonic oscillator or mechanical stirrer; mixing is achieved solely through the impact of the liquid pump 110. Impact mixing is a type of hydrodynamic mixing, with no moving parts immersed in the liquid, reducing sealing and maintenance issues.

[0067] The position and direction of the output port can be flexibly arranged. For example, the output port can be set at the bottom or side wall of the storage area, so that the impact liquid flow is directly aimed at the corner or bottom deposition area of ​​the storage area, thereby more effectively rolling up the deposited catalyst particles. Alternatively, the output port can be set as multiple small holes or nozzles to make the impact more evenly dispersed. The mixing effect can be controlled by adjusting the flow rate and pressure of the liquid pump 110. When stronger mixing is required, the output power of the pump can be increased or the split ratio can be adjusted to allow more liquid to return to the storage area from the return port. Since the returned liquid has the same composition as the liquid drawn from the storage area, no additional impurities or changes to the composition of the atomized liquid are introduced. The liquid forms a local circulation loop between the storage area, the liquid pump 110, the injection element 112, and the storage area. The atomized liquid and catalyst are continuously disturbed and mixed in this loop, maintaining a stable suspension state.

[0068] Please see Figure 6In some embodiments of this example, the mixing mechanism includes a third electrode 23 located on the side of the storage area away from the purification chamber; a first electrode extends to the periphery of the storage area, and the first electrode and the third electrode 23 form a second electric field area in the storage area. The third electrode 23 is connected to an alternating circuit so that the second electric field area forms an alternating electric field.

[0069] In this embodiment, the mixing mechanism uses an electric field drive to achieve uniform mixing of the atomized liquid and the catalyst. The third electrode 23 is located on the side of the storage area away from the purification chamber, i.e., the bottom outer side or bottom region of the storage area. This position keeps the third electrode 23 away from the gas phase space of the purification chamber above, mainly acting on the liquid inside the storage area without interfering with the migration and recovery process of microdroplets in the purification chamber. The first electrode 22 extends downward and surrounds the periphery of the storage area, forming a conductive wall surrounding the storage area. According to the aforementioned embodiment, the first electrode 22 serves as the collecting electrode for microdroplets in the gas phase section and is grounded. In this embodiment, the same first electrode 22 is reused as the reference electrode for the mixing electric field in the liquid phase section: since the first electrode 22 itself is the housing wall of the device and is already grounded, the third electrode 23 only needs to cooperate with the first electrode 22 to establish an alternating mixing electric field in the liquid of the storage area, without the need to set up a separate pair of dedicated electrodes or independent reference electrodes for the mixing function. In other words, to achieve liquid phase mixing, only a third electrode 23 needs to be added and connected to the alternating circuit. The other electrode required for mixing can directly reuse the existing grounded housing inner wall. Therefore, the entire mixing mechanism is extremely simple, with the fewest parts and significantly reduced assembly and sealing steps.

[0070] The alternating electric field in the second electric field region acts on the atomized liquid and catalyst particles in the storage area. Since the liquid is a conductive medium, the alternating electric field induces electroosmotic flow of charges within the liquid, while simultaneously generating dielectric force in the non-uniform electric field region. These two effects jointly drive the liquid to generate circulation and microscopic disturbances, causing the denser catalyst solid particles to continuously tumble, disperse, and remain suspended in the liquid, preventing the catalyst from settling to the bottom of the storage area or agglomerating due to static conditions. The atomized liquid and catalyst are repeatedly mixed under the continuous disturbance in the second electric field region, ensuring that the catalyst-containing liquid returned to the storage area maintains a uniform concentration distribution with the original liquid in the storage area.

[0071] The electric field between the third electrode 23 and the first electrode 22 enters the liquid via capacitive coupling through the container wall or dielectric isolation layer. The electrode metal itself does not directly contact the liquid, thus further preventing the formation of an electrolytic circuit. Since there is no Faraday current, no Joule heat is generated in the liquid during mixing. The entire mixing process maintains an isothermal and unheated operating state, meeting the requirements of low energy consumption and gentle safety for purification devices.

[0072] The second electric field region is located in the liquid phase and acts only on the storage region. It is independent of the first electric field region formed between the first electrode 22 and the second electrode 21 in terms of space, medium, and driving method. The first electric field region is located in the gas phase and is driven by DC high voltage to migrate and adhere charged microdroplets to the inner wall of the shell for recovery. The second electric field region is located in the liquid phase and is driven by AC sub-electrolysis voltage to mix and suspend the catalyst in the liquid. The second electric field region does not constitute the first electric field region. The alternating mixing process in the storage region does not affect the directional migration and adhesion recovery of microdroplets in the first electric field region. The two electric field regions do not interfere with each other.

[0073] There are several options for the specific arrangement of the third electrode 23. The third electrode 23 can be positioned close to the outer side of the bottom wall of the storage area, forming capacitive coupling with the liquid through the dielectric layer of the bottom wall. In this case, the third electrode 23 is completely out of contact with the liquid, resulting in a simple structure without sealing or corrosion issues. Alternatively, the third electrode 23 can be an insulating-coated electrode immersed in the liquid within the storage area. The insulating coating electrically isolates the electrode from the liquid, achieving capacitive coupling drive in the same way. The operating frequency of the alternating circuit can be adjusted according to the conductivity of the liquid. For water-based liquids with low conductivity, a lower frequency can be selected; for liquids containing catalysts and with high conductivity, a higher frequency should be selected to fall within the double-layer blocking region, ensuring that the electric field acts capacitively rather than generating a Faraday current. The amplitude of the alternating voltage can be appropriately increased within the sub-electrolysis range to obtain a stronger mixing driving force. Since the electrode does not contact the liquid, increasing the voltage will not trigger electrolysis or heat generation.

[0074] By reusing the first electrode 22, the mixing mechanism of this embodiment achieves liquid-phase mixing without adding additional electrodes. The first electrode 22 originally serves as the grounded collecting electrode for both the inner wall of the casing and gas phase recovery. In this embodiment, a third electrode 23 is simply placed at the bottom of the storage area and connected to an alternating circuit. This allows the same grounded casing wall to simultaneously serve as both a collecting electrode and a mixing reference electrode, eliminating the need for separate electrode pairs and corresponding insulation and support structures for mixing. This simplifies the overall structure, reduces assembly and sealing steps, and improves reliability. Simultaneously, since the mixing field and the recovery field share the same grounded reference, the two electric fields are naturally isolated, and the AC mixing process does not interfere with the DC recovery process. The mixing mechanism does not require moving parts such as ultrasonic oscillators or mechanical stirrers, and no moving parts are immersed in the liquid, reducing sealing and maintenance needs, resulting in low energy consumption and minimal temperature rise. The catalyst remains uniformly suspended in the storage area, ensuring a stable and consistent concentration of catalyst-containing liquid flowing back to the storage area in each cycle. This guarantees a uniform and controllable amount of catalyst carried by microdroplets during the purification process, improving the gas purification effect.

[0075] In addition, it should be noted here that, Figure 6To maintain the continuity of the first electrode 22, the gas inlet 101 is hidden. The gas inlet 101 itself occupies a limited area of ​​the sidewall and will not affect the extension of the first electrode 22.

[0076] In some embodiments of this application, the purification device based on discharge-excited catalytic microdroplets further includes an auxiliary droplet capture mechanism; the auxiliary droplet capture mechanism includes a fourth electrode 32 and a fifth electrode 33, which are spaced apart to form a third electric field region; the third electric field region is located downstream of the first electric field region and is closer to the gas outlet 102 than the first electric field region, so as to capture residual microdroplets.

[0077] In this embodiment, the purification device based on discharge-excited catalytic microdroplets further includes an auxiliary droplet capture mechanism. This auxiliary droplet capture mechanism is located in the upper part of the purification chamber and is used to further collect residual microdroplets that were not completely captured after passing through the first electric field region.

[0078] The auxiliary droplet capture mechanism includes a fourth electrode 32 and a fifth electrode 33. The fourth electrode 32 and the fifth electrode 33 are spaced apart, forming a third electric field region between them. This third electric field region is also an electrostatic field region, capable of applying an electric field force to charged microdroplets entering it. Unlike the first electric field region, the third electric field region is located downstream of the first electric field region, that is, further back along the airflow direction, and closer to the gas outlet 102 relative to the first electric field region. In other words, the airflow first passes through the first electric field region, then through the third electric field region, and finally exits from the gas outlet 102.

[0079] The purpose of setting up the third electric field region is to capture residual microdroplets. In the first electric field region, most microdroplets have migrated and attached to the inner wall of the shell or the electrode surface under the action of the electric field force. However, some microdroplets, due to their small particle size, insufficient charge, or excessive airflow velocity, have not been effectively captured and continue to move upward with the airflow. After these residual microdroplets enter the third electric field region, they are subjected to the electric field force of the new electric field formed between the fourth electrode 32 and the fifth electrode 33, causing them to migrate again and attach to the electrode surface or auxiliary collection structure, thereby achieving secondary capture.

[0080] The third electric field zone is closer to the gas outlet 102, meaning that residual microdroplets are intercepted by the final electric field just before the gas is discharged from the device. This minimizes the possibility of microdroplets escaping with the airflow, reduces catalyst loss, and also prevents uncaptured droplets from being released into the indoor environment and causing secondary pollution.

[0081] The specific forms of the fourth electrode 32 and the fifth electrode 33 can be designed according to requirements. For example, the fourth electrode 32 can be a central electrode, and the fifth electrode 33 can be a surrounding cylindrical electrode, similar in structure to the first electrode 22 and the second electrode 21. Alternatively, different configurations such as parallel plate electrodes or needle-mesh electrodes can be used. The electric field strength of the third electric field region can be the same as or different from that of the first electric field region. It can usually be set slightly weaker to save energy, or set stronger to ensure efficient capture.

[0082] Since the residual microdroplets still contain catalyst, capturing and collecting these microdroplets in the third electric field zone and then refluxing them can further improve the catalyst recovery rate and extend the continuous operation time of the device after a single catalyst addition. Simultaneously, the third electric field zone also further treats any volatile organic compounds and microorganisms that may remain in the gas, further enhancing the purification effect.

[0083] Please see Figure 2 In some embodiments of this application, the auxiliary droplet capture mechanism further includes a flow guide 31, which is an arc-shaped structure. A through hole is provided in the middle of the flow guide 31 for airflow to pass through. The through hole is centered with the fourth electrode 32, and the polarity of the fourth electrode 32 is opposite to the polarity of the charge carried by the microdroplet, so as to attract the microdroplet to migrate towards the fourth electrode 32. The periphery of the flow guide 31 extends towards the inner wall of the purification chamber, and a gap is left between it and the inner wall, so that the liquid attached to the flow guide 31 flows along the surface of the flow guide 31 through the gap to the inner wall and flows back to the storage area.

[0084] In this embodiment, the auxiliary droplet capture mechanism further includes a flow guide shroud 31. The flow guide shroud 31 has an arc-shaped structure with a through-hole in its middle for airflow. The through-hole is centered with the fourth electrode 32, meaning the central axis of the through-hole coincides with the central axis of the fourth electrode 32. The fourth electrode 32 is located at the exact center of the through-hole or directly opposite it. Simultaneously, the polarity of the fourth electrode 32 is opposite to the polarity of the charge carried by the microdroplet. This allows the fourth electrode 32 to generate an electrostatic attraction to the charged microdroplets passing through the third electric field region, attracting the microdroplets to migrate towards the fourth electrode 32.

[0085] The flow guide shroud 31 extends towards the inner wall of the purification chamber, leaving a gap between it and the inner wall. This structure allows the flow guide shroud 31 to divide the space above the purification chamber into a central region and an edge region. Airflow passes through the central through-hole, while liquid can flow through the edge gap.

[0086] When residual microdroplets enter the third electric field region with the airflow, the microdroplets experience an electric force towards the fourth electrode 32 due to the opposite polarity of the fourth electrode 32 to the charge of the microdroplets. Some microdroplets directly pass through the through-hole and impact the surface of the fourth electrode 32, thus adhering to it; others may first contact the surface of the flow guide shroud 31 during migration. Since the flow guide shroud 31 has an arc-shaped structure with a smooth and curved surface, the liquid adhering to it converges and flows along the arc surface towards the edge. When the liquid reaches the edge of the flow guide shroud 31, it flows or drips onto the inner wall through the gap between the flow guide shroud 31 and the inner wall. The inner wall is connected to the storage area, so the liquid can continue to flow downwards along the inner wall and eventually return to the storage area.

[0087] The polarity configuration of the fourth electrode 32 is crucial for attracting microdroplets. If the polarity of the fourth electrode 32 is the same as that of the microdroplet, a repulsive force will be generated, which is detrimental to capture. Therefore, setting the polarity of the fourth electrode 32 to be opposite to the charge carried by the microdroplet allows the microdroplet to be actively attracted to the vicinity of the fourth electrode 32, greatly improving the capture efficiency. Simultaneously, the via is aligned with the fourth electrode 32, ensuring that the direction of the attraction is roughly consistent with the airflow direction. This allows the microdroplet to reach the fourth electrode 32 without significantly deviating from the airflow direction, reducing the possibility of the microdroplet being carried away by the airflow during migration.

[0088] The arc-shaped structure of the flow guide shroud 31 facilitates the collection and guidance of liquid. If the flow guide shroud 31 were flat, the liquid might stagnate on the surface or flow irregularly in various directions. The arc-shaped surface allows the liquid to flow naturally to the lowest point of the edge and then through the gaps to the inner wall. In addition, the arc-shaped surface also helps to reduce airflow resistance, allowing the airflow to pass smoothly through the central through-hole.

[0089] With this structure, residual microdroplets are actively attracted and captured by the fourth electrode 32. The liquid attached to the fourth electrode 32 and the flow guide shroud 31 is guided to the inner wall and returned to the storage area, thereby further improving the catalyst recovery rate, reducing catalyst loss, and avoiding excessive accumulation of liquid on the electrode surface, which would affect the electric field distribution or discharge effect.

[0090] In some embodiments of this application, a microdroplet collector 34 is also provided in the third electric field region. The microdroplet collector 34 is used to collect residual microdroplets moving in the third electric field region. The microdroplet collector 34 is connected to the inner wall of the purification chamber to guide the collected catalyst-containing liquid to the inner wall and return it to the storage area.

[0091] In this embodiment, a microdroplet collector 34 is also provided in the third electric field region. The microdroplet collector 34 is a component specifically designed to collect residual microdroplets. Its function is to intercept and collect residual microdroplets that are moving with the airflow but have not yet been captured by the electrode or the flow guide 31 in the third electric field region.

[0092] The microdroplet collector 34 is connected to the inner wall of the purification chamber, either through direct contact or indirect fixation via other structures. When residual microdroplets move in the third electric field region, they collide with the surface of the microdroplet collector 34. Due to surface tension and wettability, the microdroplets adhere to the collector and gradually coalesce into larger droplets. These droplets contain catalyst brought from the storage area.

[0093] The microdroplet collector 34 is connected to the inner wall, so the liquid adhering to the collector can flow to the inner wall along the guide structure on the surface of the collector or inside it. The inner wall is connected to the storage area at the bottom, and after the liquid reaches the inner wall, it flows naturally downward along the inner wall and eventually flows back to the storage area.

[0094] In this way, the microdroplet collector 34 further improves the capture efficiency of residual microdroplets, especially for microdroplets with smaller particle size and lower charge, supplementing the shortcomings of electric field capture through physical interception. At the same time, since the collector is connected to the inner wall, the collected catalyst-containing liquid can smoothly enter the reflux path, avoiding liquid stagnation on the collector and causing secondary entrainment or accumulation.

[0095] The microdroplet collector 34 can take the form of a porous plate, wire mesh, baffle, fiber layer, or other structure with a large surface area and good wettability. Its placement can be between the fourth electrode 32 and the fifth electrode 33, below or around the flow guide shroud 31, as long as it can effectively intercept residual microdroplets.

[0096] Please see Figure 7 In some embodiments of this application, the purification device based on discharge-excited catalytic microdroplets includes a first chamber 1, a second chamber 2, and a third chamber 3 arranged sequentially from bottom to top; a gas inlet 101 is disposed in the first chamber 1, and a gas outlet 102 is disposed in the third chamber 3; a mixing mechanism 12 and a microdroplet generating mechanism are disposed in the first chamber 1, an electric field generator is disposed in the second chamber 2, and an auxiliary droplet capturing mechanism is disposed in the third chamber 3.

[0097] In this embodiment, the purification device based on discharge-excited catalytic microdroplets comprises a first chamber 1, a second chamber 2, and a third chamber 3 arranged sequentially from bottom to top. These three chambers are arranged vertically in layers and are interconnected to form an integral structure.

[0098] A gas inlet 101 is located in the first chamber 1, and a gas outlet 102 is located in the third chamber 3. The gas to be treated enters the device through the lower gas inlet 101, flows sequentially from bottom to top through the first chamber 1, the second chamber 2, and the third chamber 3, and finally exits from the upper gas outlet 102. This bottom-in, top-out airflow direction is beneficial for utilizing gravity to allow the droplets to fall naturally, and also facilitates the coordination between the radial migration effect of the electric field on the microdroplets and the axial airflow.

[0099] The mixing mechanism 12 and the microdroplet generating mechanism are located in the first chamber 1. The first chamber 1 is located at the bottom of the device, and its bottom has a storage area. The mixing mechanism 12 (e.g., an ultrasonic oscillator) is located in the storage area to maintain a uniform mixture of the atomized liquid and the catalyst. The microdroplet generating mechanism is also located in the first chamber 1, usually above the storage area, and converts the atomized liquid mixed with the catalyst into microdroplets and releases them upwards. The first chamber 1 performs the functions of liquid storage, mixing, and microdroplet generation, and is the liquid source and atomization source of the device.

[0100] An electric field generator is located in the second chamber 2. The second chamber 2 is situated above the first chamber 1 and contains a first electrode 22 and a second electrode 21, forming a first electric field region between them. Microdroplets generated from the first chamber 1 enter the second chamber 2 with the airflow, become charged in the first electric field region, and migrate and adhere to the inner wall of the shell or the electrode surface under the influence of the electric field force. Simultaneously, a discharge-induced reaction occurs, degrading volatile organic compounds and inactivating microorganisms. The second chamber 2 is the main reaction zone and primary separation zone of the device.

[0101] An auxiliary droplet capture mechanism is located in the third chamber 3. The third chamber 3 is situated above the second chamber 2, near the gas outlet 102. The auxiliary droplet capture mechanism includes a third electric field region formed by a fourth electrode 32 and a fifth electrode 33, as well as a flow guide 31, a microdroplet collector 34, and other structures. Residual microdroplets that were not completely captured in the second chamber 2 enter the third chamber 3 with the airflow. There, they are again subjected to electric field forces in the third electric field region, attracting them with the fourth electrode 32 or intercepting them with the flow guide 31 or the microdroplet collector 34, ultimately flowing back along the inner wall to the storage area. The third chamber 3 serves as a secondary capture and flow guide for recovery. In some embodiments, a sealing ring 4 can be provided between adjacent chambers to ensure a sealing effect.

[0102] This application also provides a purification method based on discharge-excited catalytic microdroplets, which employs the aforementioned purification device based on discharge-excited catalytic microdroplets. This purification method can effectively improve the removal efficiency of volatile organic compounds and microorganisms, while simultaneously achieving catalyst recycling through liquid reflux, reducing catalyst loss with airflow, lowering the risk of ozone and other byproduct formation, and contributing to the long-term stable operation of the device.

[0103] In some embodiments of this application, the purification method based on discharge-excited catalytic microdroplets includes the following steps: S100. The atomizing liquid and catalyst are mixed evenly in the storage zone. The storage zone is located at the bottom of the purification chamber. The atomizing liquid is usually an aqueous solution, and the catalyst is an insoluble solid nanoparticle, such as nano-titanium dioxide or nano-zinc oxide. The catalyst is kept uniformly suspended in the atomizing liquid by the impact of a mixing mechanism 12, such as an ultrasonic oscillator or a shared liquid pump 110, preventing sedimentation or agglomeration. This step ensures a stable catalyst content in the subsequently generated microdroplets.

[0104] S200: The atomized liquid mixed with the catalyst is converted into microdroplets and released. Microdroplet generating mechanisms, such as jet-type microdroplet generators or ultrasonic atomizing plates, atomize the liquid into micron- or submicron-sized droplets. These microdroplets have a large specific surface area, enabling them to efficiently contact gaseous pollutants. The microdroplets are released into the purification chamber, typically entering the airflow channel upwards.

[0105] S300: Microdroplets are transported to the first electric field region via airflow. In this region, the microdroplets are acted upon by the electric field force and migrate towards the inner wall of the shell and / or the surface of the electrodes, where they adhere. This allows the catalyst-containing liquid formed after adhesion to flow back to the storage area along the wall surface. The first electric field region is formed by the electric field between the first electrode 22 and the second electrode 21. Microdroplets enter this region with the airflow and become induced or contact-charged, acquiring positive or negative charges. Under the action of the radial electric field, the charged microdroplets are driven by the electric field force to migrate towards the electrode surface with opposite polarity. For example, when the inner wall of the shell is the first electrode 22 and grounded, and the central rod-shaped electrode is the second electrode 21 and connected to a positive high voltage, the positively charged microdroplets move towards the inner wall of the shell. After adhering to the wall surface, the microdroplets coalesce into a liquid film. Since the wall surface is connected to the storage area, the liquid flows naturally downwards along the wall surface under gravity, eventually flowing back to the storage area.

[0106] In some embodiments of this application, the purification method based on discharge-excited catalytic microdroplets further includes: S101. The catalyst uses catalyst particles. The surface area of ​​a single microdroplet is determined based on its diameter, and the projected coverage area of ​​a single catalyst particle on the droplet surface is determined based on the particle size of the catalyst particles. The microdroplet is approximated as a sphere, and its surface area can be obtained using the formula for the surface area of ​​a sphere. Simultaneously, the projected coverage area of ​​a single catalyst particle on the droplet surface is calculated based on the particle size of the catalyst particles. The catalyst particles are also approximated as spherical, and their projection onto the plane is a circle, the area of ​​which can be calculated from the particle size.

[0107] S102. Based on the target coverage of the catalyst on the surface of the microdroplets, determine the number of catalyst particles required to adhere to the surface of a single microdroplet. The target coverage is usually a set percentage; for example, a sparse monolayer coverage has a lower coverage, while a densely packed coverage has a higher coverage. The required number of particles can be obtained by multiplying the surface area of ​​a single droplet by the target coverage and then dividing by the projected area of ​​a single catalyst particle.

[0108] S103. Based on the ratio of catalyst particle number to microdroplet number, determine the volume fraction or mass concentration of catalyst in the atomizing liquid to determine the amount of catalyst to be added. This calculation takes into account factors such as atomization flow rate, droplet diameter, catalyst particle size and density, so that the amount added can meet the surface coverage requirements without excessive waste.

[0109] S104. Add the catalyst to the atomizing liquid according to the determined amount. The catalyst can be added to the atomizing liquid in the storage area all at once, or it can be continuously added during the operation of the device to maintain a stable catalyst concentration in the atomizing liquid.

[0110] The following is a specific calculation process in one embodiment of this application. Note that this embodiment is for laboratory verification and is not for use in actual products.

[0111] The calculation parameters are as follows: Total liquid volume: 35 mL; Atomization flow rate: 0.5 mL / min; Microdroplet diameter: 3 μm; Nanocatalyst particle size: 150 nm was selected as the median value of 100–200 nm; Coverage of the nanocatalyst on the droplet surface: 5%; Assume the catalyst is sparsely monolayered on the droplet surface; Assume the catalyst density is 4 g / cm³; Assume that during droplet formation, the proportion of catalyst carried in the droplet is the same as that in the original solution.

[0112] 1) The total liquid volume inside the chamber is set as follows:

[0113] 2) The volume of a single 3μm microdroplet, approximating the droplet as a sphere, is:

[0114] Where D = 3μm, substituting this into the equation yields:

[0115] And because:

[0116] Therefore, the volume of a single droplet is:

[0117] 3) If the atomization flow rate is 0.5 mL / min, then the number of droplets produced per minute is:

[0118] Right now:

[0119] III. Calculation of Catalyst Addition Amount 1) Surface Coverage Model: Let the droplet diameter be D, the nanocatalyst particle size be d, and the coverage rate be f. Then the catalyst volume fraction can be approximated as:

[0120] Substituting: f = 0.05; d = 0.15 μm; D = 3 μm get:

[0121] 2) The corresponding catalyst concentration: If the catalyst density is 4 g / mL, then the required catalyst mass per 1 mL of liquid is:

[0122] Right now:

[0123] 3) The total amount of catalyst in 35 mL of liquid is:

[0124] 4) Calculation of the corresponding catalyst output rate. Since the atomization flow rate is 0.5 mL / min, and assuming the catalyst is output in the same proportion as the droplets, the amount of catalyst entering the gas-liquid two-phase flow per minute is approximately:

[0125] As described above, to estimate the appropriate amount of catalyst in this device and demonstrate the necessity of setting up a catalyst recovery structure, a simplified calculation was performed on the microdroplet generation chamber. Assuming the total liquid volume at the bottom is 35 mL, the atomization flow rate of the microdroplet generator is 0.5 mL / min, and the average diameter of the formed microdroplets is taken as 3 μm, and the microdroplets are approximated as spherical, the volume of a single droplet is approximately 1.41 × 10⁻⁶. Based on 11 mL, it can be calculated that the microdroplet generation rate during device operation is approximately 3.54 × 10¹⁰ droplets / min, which means that approximately 35.4 billion microdroplets can be generated per minute; when all 35 mL of liquid is atomized, the corresponding theoretical total number of droplets is approximately 2.48 × 10¹², and the device can continue to operate for approximately 70 minutes at the current atomization flow rate.

[0126] In estimating the catalyst dosage, we further assume that the nanocatalyst particle size is 150 nm, representing the median of the 100–200 nm particle size range, and that the catalyst is sparsely distributed on the microdroplet surface with a 5% coverage. Based on the relationship between the droplet surface area and the projected area of ​​the nanoparticles, the volume fraction of the catalyst in the liquid can be estimated to be approximately 1%. If the catalyst density is 4 g / cm³, the corresponding catalyst addition concentration is approximately 40 mg / mL, or 40,000 mg / L. Therefore, in a 35 mL liquid system, the total amount of nanocatalyst required is approximately 1400 mg, or about 1.4 g.

[0127] Furthermore, at an atomization flow rate of 0.5 mL / min, assuming the catalyst and microdroplets enter the upstream reaction and separation process in the same proportion, the corresponding catalyst output is approximately 20 mg / min. This result indicates that even under the conservative assumption of only 5% sparse coverage, the amount of catalyst used in the system is still relatively large. If the device lacks an effective gas-liquid-solid separation and reflux structure during operation, the catalyst will be continuously lost with the microdroplets, leading not only to a gradual decrease in the effective catalyst concentration and purification efficiency in the reaction zone, but also potentially entering the downstream of the device with the gas flow, causing secondary release and downstream pollution risks. Therefore, it is necessary to set up a middle pre-separation chamber and an upper droplet capture and guiding chamber in this device, and to reflux the recovered liquid back to the bottom microdroplet generating chamber, to maintain a stable catalyst concentration, ensure continuous purification performance, and prevent catalyst escape.

[0128] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A purification device based on discharge-excited catalytic microdroplets, characterized in that, The purification device based on discharge-excited catalytic microdroplets includes: The housing has a purification chamber for purifying gas, and the bottom of the purification chamber is provided with a storage area for storing atomizing liquid and catalyst. The purification chamber has a gas inlet and a gas outlet. A mixing mechanism; the mixing mechanism is used to uniformly mix the atomizing liquid and the catalyst in the storage area; Microdroplet generating mechanism; the microdroplet generating mechanism is disposed in the purification chamber and is used to convert the atomized liquid mixed with catalyst into microdroplets; An electric field generator; the electric field generator includes a first electrode and a second electrode, the first electrode and the second electrode being spaced apart to form a first electric field region between the first electrode and the second electrode; the first electric field region is located between the gas inlet and the gas outlet; The purification device based on discharge-excited catalytic microdroplets is configured such that: the microdroplets released by the microdroplet generating mechanism are transported to the first electric field region by airflow, and migrate and attach to the inner wall of the shell and / or the surface of the electrode under the action of electric field force in the first electric field region; the inner wall of the shell and / or the surface of the electrode are connected to the storage area, so that the catalyst-containing liquid formed after attachment flows back to the storage area along the wall surface. The first electrode is formed on the inner wall of the housing, and the second electrode is located inside the purification chamber, such that the first electrode surrounds the second electrode. The first electrode is a cylindrical electrode extending along the axial direction of the purification chamber, and the second electrode is a rod-shaped electrode arranged along the axial direction of the purification chamber. The first electric field region between the first electrode and the second electrode forms an electric field along the radial direction of the purification chamber. The airflow direction of the purification chamber is along the axial direction of the purification chamber, the extension direction of the cylindrical electrode is consistent with the airflow direction, and the airflow direction intersects with the electric field direction of the first electric field region. The purification device based on discharge-excited catalytic microdroplets also includes an auxiliary droplet capture mechanism; the purification device based on discharge-excited catalytic microdroplets includes a first chamber, a second chamber, and a third chamber arranged sequentially from bottom to top; The gas inlet is located in the first chamber, and the gas outlet is located in the third chamber; The mixing mechanism and the microdroplet generating mechanism are disposed in the first chamber, the electric field generator is disposed in the second chamber, and the auxiliary droplet capturing mechanism is disposed in the third chamber.

2. The purification device based on discharge-excited catalytic microdroplets as described in claim 1, characterized in that, The second electrode is configured to be connected to the positive terminal of a high-voltage power supply, and the first electrode is grounded; the direction of the electric field between the second electrode and the first electrode is radially from the second electrode to the first electrode.

3. The purification device based on discharge-excited catalytic microdroplets as described in claim 1 or 2, characterized in that, The mixing mechanism includes an ultrasonic oscillator, which is at least partially disposed within the storage area.

4. The purification device based on discharge-excited catalytic microdroplets as described in claim 1 or 2, characterized in that, The purification device based on discharge-excited catalytic microdroplets also includes a liquid pump, which has a first output port and a second output port. The first output port is connected to the spray element of the microdroplet generating mechanism, and is used to deliver the atomized liquid mixed with the catalyst to the spray element to form microdroplets; The second output port is connected to the storage area and is used to output liquid to the storage area to impact and mix the atomized liquid and the catalyst.

5. The purification device based on discharge-excited catalytic microdroplets as described in claim 2, characterized in that, The mixing mechanism includes a third electrode located on the side of the storage area opposite to the purification chamber; The first electrode extends to the periphery of the storage area, and the first electrode and the third electrode form a second electric field region in the storage area. The third electrode is connected to an alternating circuit so that the second electric field region forms an alternating electric field.

6. The purification device based on discharge-excited catalytic microdroplets as described in claim 1, characterized in that, The auxiliary droplet capture mechanism includes a fourth electrode and a fifth electrode, which are spaced apart to form a third electric field region. The third electric field region is located downstream of the first electric field region and closer to the gas outlet than the first electric field region, in order to capture residual microdroplets.

7. The purification device based on discharge-excited catalytic microdroplets as described in claim 6, characterized in that, The auxiliary droplet capture mechanism also includes a flow guide hood, which has an arc-shaped structure. A through hole is provided in the middle of the flow guide hood to allow airflow to pass through. The through hole is centered with the fourth electrode, and the polarity of the fourth electrode is opposite to the polarity of the charge carried by the microdroplet, so as to attract the microdroplet to migrate towards the fourth electrode. The flow guide extends around the inner wall of the purification chamber and has a gap between it and the inner wall, so that the liquid adhering to the flow guide flows along the surface of the flow guide through the gap to the inner wall and back to the storage area.

8. The purification device based on discharge-excited catalytic microdroplets as described in claim 7, characterized in that, The third electric field region is also equipped with a microdroplet collector, which is used to collect residual microdroplets moving in the third electric field region; the microdroplet collector is connected to the inner wall of the purification chamber to guide the collected catalyst-containing liquid to the inner wall and return it to the storage area.

9. A purification method based on discharge-excited catalytic microdroplets, characterized in that, The purification method based on discharge-excited catalytic microdroplets employs the purification device based on discharge-excited catalytic microdroplets as described in any one of claims 1 to 8, and the purification method based on discharge-excited catalytic microdroplets includes the following steps: The atomizing liquid and catalyst are mixed evenly in the storage area; The atomized liquid containing the catalyst is converted into microdroplets and released; The microdroplets are transported to the first electric field region by airflow, where they are subjected to electric field forces to migrate and adhere to the inner wall of the shell and / or the surface of the electrode, so that the catalyst-containing liquid formed after adhesion flows back to the storage area along the wall.

10. The purification method based on discharge-excited catalytic microdroplets as described in claim 9, characterized in that, The purification method based on discharge-excited catalytic microdroplets also includes: The catalyst is composed of catalyst particles. The surface area of ​​a single microdroplet is determined according to the diameter of the microdroplet, and the projected coverage area of ​​a single catalyst particle on the droplet surface is determined according to the particle size of the catalyst particles. Based on the target coverage of the catalyst on the surface of the microdroplet, determine the number of catalyst particles required to adhere to the surface of a single microdroplet; Based on the ratio of the number of catalyst particles to the number of microdroplets, the volume fraction or mass concentration of the catalyst in the atomizing liquid is determined, so as to determine the amount of catalyst to be added. The catalyst is added to the atomizing liquid according to the determined amount.

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