Dielectric barrier plasma discharge device

Abstract

The invention discloses a dielectric barrier plasma discharge device. The dielectric barrier plasma discharge device comprises a handheld shell, a dielectric barrier discharge unit and an integrated control board, in the working process, the fan driven by the motor firstly sucks external environment air into the inner cavity of the fixing plate through the air inlet; meanwhile, the integrated control board outputs high-frequency and high-voltage electric energy which is applied between the anode copper bar serving as an electrode and the cathode copper sheet coated with the ceramic dielectric, and a strong electric field area is formed. The electric field can effectively break down an air medium flowing through the fixed plate, so that the air medium is ionized and converted into a low-temperature plasma state. And the generated plasma flows directionally under the flow guide action of the front connecting plate, and is sprayed outwards in a stable jet flow form through the conical tuyere. The device adopts a modular compact design, integrates a power supply, a control system and a discharge unit into a whole, realizes the function of stably generating atmospheric pressure low-temperature plasma in a handheld operation mode, and is suitable for a mobile application scene of plasma processing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of plasma discharge, in particular to a dielectric barrier plasma discharge device. BACKGROUND

[0002] As a highly efficient material processing and pollutant degradation method, plasma technology has been widely used in industry, medicine, environmental protection and other fields. As a common way to generate low-temperature plasma, dielectric barrier discharge (DBD) is particularly concerned for its stable implementation at normal pressure.

[0003] In the prior art, the dielectric barrier plasma generation device still has obvious structural limitations. First, in the overall form, the fixed structure of horizontal or vertical type is generally adopted, which is bulky and inconvenient to move, seriously limiting its application scenarios in on-site operation, personal care and small-sized equipment. Secondly, in the design of discharge structure, most products still use the traditional coaxial cylinder or double parallel plate electrode arrangement. Although this symmetrical structure is easy to implement, its electric field distribution is relatively uniform, which easily leads to a large number of randomly distributed micro-discharge channels. These micro-discharges not only have uneven spatial and temporal distribution, but also have short duration and low energy efficiency, affecting the uniformity and stability of plasma generation.

[0004] In addition, in the circuit architecture level, the main power conversion part of the existing device mostly adopts the conventional two-level inverter circuit topology. In the high-frequency switching process, this topology makes the power semiconductor device bear a high voltage stress (usually the entire DC bus voltage), which increases the risk of device breakdown and system failure rate. At the same time, the output voltage waveform of the two-level circuit has high harmonic content, which not only increases the burden and volume of the filter circuit, but also may cause electromagnetic interference to the surrounding electronic equipment.

[0005] Therefore, the industry urgently needs a new dielectric barrier plasma discharge device scheme that has hand-held portability, discharge stability and circuit efficiency, thereby solving the above-mentioned deficiencies and drawbacks of the prior art. SUMMARY

[0006] In view of the deficiencies of the existing plasma generation device, such as the overall heavy horizontal or vertical structure, lack of hand-held portability, the dielectric barrier discharge structure generally adopts coaxial or double parallel plate design, which easily leads to random distribution of discharge and short life of micro-discharge channel, and the main power circuit often chooses two-level inverter topology, resulting in high voltage stress on the switching device and high output harmonic content, the present application proposes an innovative solution.

[0007] In order to achieve the above object, the application provides a dielectric barrier plasma discharge device, comprising a handheld shell, a dielectric barrier discharge unit and an integrated control board.

[0008] The handheld shell comprises a blast nozzle, a driving motor, a main shell, a handle front shell, a driving motor, a fan slot, a handle rear shell, a power switch, a centrifugal fan and a rear shell.

[0009] The dielectric barrier discharge unit is arranged in the handheld shell and comprises a front connecting plate, an anode copper rod, a ceramic sheet, a cathode copper sheet and a fixing plate.

[0010] The integrated control board is arranged in the handheld shell and connected with the dielectric barrier discharge unit, and the positive line of the integrated control board is connected with the anode copper rod of the dielectric barrier discharge unit, and the negative line of the integrated control board is connected with the cathode copper sheet of the dielectric barrier discharge unit.

[0011] As an improved scheme of the application, the handheld shell is configured to realize portable handheld operation and plasma generation function of the device.

[0012] As an improved scheme of the application, in the dielectric barrier discharge unit, the ceramic sheet covers the surface of the cathode copper sheet, and the anode copper rod and the cathode copper sheet covered with the ceramic sheet jointly form a parallel discharge structure.

[0013] As an improved scheme of the application, the main power circuit of the integrated control board is a full-bridge three-level inverter topology circuit.

[0014] As an improved scheme of the application, the control algorithm adopted for the main power circuit in the integrated control board is an active disturbance rejection control (ADRC) closed-loop algorithm.

[0015] The beneficial effects of this invention are as follows: Compared with the prior art, this invention provides a dielectric barrier plasma discharge device, comprising a handheld housing, a dielectric barrier discharge unit, and an integrated control board. During operation, a motor-driven fan first draws ambient air into the internal cavity of the fixed plate through the air inlet; simultaneously, the integrated control board outputs high-frequency, high-voltage electrical energy, applied between the anode copper rod (serving as an electrode) and the cathode copper sheet coated with ceramic dielectric, forming a strong electric field region. This electric field effectively breaks down the air dielectric flowing through the fixed plate, causing it to ionize and transform into a low-temperature plasma state. The generated plasma then flows directionally under the guidance of the front plate, and finally is ejected outward in a stable jet form through a conical nozzle. The innovation of this device lies in its modular and compact design, integrating the power supply, control system, and discharge unit into one unit, achieving the function of stably generating atmospheric pressure low-temperature plasma in handheld operation mode, suitable for various mobile application scenarios requiring localized plasma processing. Attached Figure Description

[0016] Figure 1 This is a front view of the perspective view of the present invention;

[0017] Figure 2 This is a side view of a perspective view of the present invention;

[0018] Figure 3 This is an exploded view of the three-dimensional view of the present invention;

[0019] Figure 4 This is a structural diagram of the dielectric barrier discharge electrode "rod-plate" of the present invention;

[0020] Figure 5 This is a cross-sectional view of the "rod-plate" structure of the dielectric barrier discharge electrode of the present invention;

[0021] Figure 6 This is an exploded view of the dielectric barrier discharge electrode structure of the present invention;

[0022] Figure 7 This is the circuit topology for integrating the ADRC closed-loop algorithm function of the present invention.

[0023] The symbols for the main components are explained below:

[0024] 1. Handheld housing; 2. Dielectric barrier discharge unit; 3. Integrated control board; 11. Nozzle; 21. Front connector plate; 22. Anode copper rod; 23. Ceramic plate; 24. Cathode copper plate; 25. Fixing plate; 3. Integrated control board; 12. Main housing; 13. Handle front housing; 14. Drive motor; 15. Fan slot; 16. Handle rear housing; 17. Power switch; 18. Centrifugal fan; 19. Rear housing Detailed Implementation

[0025] To more clearly illustrate the present invention, the invention will be further described below with reference to the accompanying drawings.

[0026] In the following description, specific examples are given to provide a more in-depth understanding of the invention. It is obvious that the described embodiments are merely some, not all, of the embodiments of the invention. It should be understood that the specific embodiments described are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] It should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the said feature, integral, step, operation, element, or component, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, or combinations thereof.

[0028] like Figures 1 to 3 As shown, the dielectric barrier plasma discharge device provided by the present invention consists of three main functional modules: a handheld housing 1, a dielectric barrier discharge unit 2, and an integrated control board 3.

[0029] Regarding the handheld housing 1: The handheld housing 1 serves as the physical carrier of the device and the human-machine interface. Its specific components are: the main outer shell 12, the front handle shell 13, and the rear handle shell 16 together form an ergonomic hand grip; the nozzle 11 is located at the front end for the final ejection of the plasma jet; the drive motor 14 and its associated centrifugal fan 18 are set in the fan slot 15 inside the housing, responsible for generating directional airflow; the power switch 17 is located in a position on the handle for easy operation; and the rear shell 19 is used for enclosure and provides space for possible battery compartments or interfaces.

[0030] Regarding dielectric barrier discharge unit 2: This unit is the core component for achieving plasma excitation; its assembly relationship is described in [reference needed]. Figures 4 to 6 Specifically, it includes: a fixed plate 25, serving as a basic support with an internal cavity for airflow; a cathode copper sheet 24, fixed to the fixed plate; a ceramic sheet 23, serving as a dielectric barrier layer, one side of which completely covers and is firmly attached to the surface of the cathode copper sheet 24; and an anode copper rod 22, embedded in the fixed plate for relative fixation and suspended above the cathode copper sheet covered with the ceramic sheet 23, parallel to it. Thus, the anode copper rod 22 and the cathode copper sheet 24 covered with the ceramic dielectric layer together construct a rod-plate discharge structure. Compared to traditional symmetrical structures, the advantage of this design is that it can generate an extremely strong local electric field near the tip of the anode copper rod.

[0031] Regarding Integrated Control Board 3: See [link / reference] Figure 7 This control board integrates signal processing, power drive, and control logic. Its core innovations are reflected in two aspects: 1. Main power circuit: It adopts a full-bridge three-level inverter topology circuit (see reference).Figure 7 (Illustrative diagram). This topology reduces the voltage stress on each switch during turn-off to half the DC bus voltage. This not only improves system reliability but also creates conditions for selecting lower-cost, higher-performance medium-voltage power devices, while effectively reducing the harmonic distortion rate of the output voltage. 2. Control Algorithm: An ADRC (Active Disturbance Rejection Controller) closed-loop algorithm is used for the main power circuit. This advanced algorithm can estimate and compensate for various disturbances inside and outside the system (such as load changes and parameter drift) in real time, thereby ensuring that the dynamic process of plasma generation has fast response and excellent robust stability.

[0032] The workflow of this invention is as follows:

[0033] 1. Air intake and activation: When the user turns on the power switch 17, the drive motor 14 drives the centrifugal fan 18 to rotate at high speed, drawing in ambient air from the air inlet and allowing it to flow through the cavity inside the fixed plate 25.

[0034] 2. Electric Field Establishment and Gas Ionization: Simultaneously, the integrated control board 3 begins operation, outputting precisely modulated high-frequency, high-voltage alternating current to its positive line (connected to the anode copper rod 22) and negative line (connected to the cathode copper plate 24). A powerful electric field is established in the narrow gap between the anode copper rod 22 and the cathode copper plate 24. This electric field is sufficient to break down the air medium flowing through this area, causing it to ionize and transform into a low-temperature plasma state.

[0035] 3. Plasma transport and ejection: The generated plasma is accelerated and focused under the guidance of the airflow and the front plate 21, and finally ejected outward in the form of a stable, concentrated, low-temperature plasma jet that can be used for targeted treatment through the conical nozzle 11.

[0036] Further explanation of the preferred implementation scheme:

[0037] In the dielectric barrier discharge unit 2, the ceramic sheet 23 is preferably made of high-purity alumina ceramic to ensure good insulation and resistance to arc corrosion.

[0038] The integrated control board 3 can further integrate a wireless communication module (such as Bluetooth) to enable remote intelligent control of the working mode and parameter monitoring.

[0039] To further enhance portability, the interior of the handheld housing (1) may be designed with a dedicated compartment to accommodate a rechargeable lithium battery, enabling true wireless operation.

[0040] The advantages of this invention are:

[0041] 1. Improved ease of operation and user experience, enabling greater application mobility and broader application scenarios. The plasma generator has been transformed from a fixed laboratory or industrial device into a freely movable handheld tool. Through an integrated, ergonomic housing design, users can operate it directly in their hands, as easily as using a power tool, significantly lowering the barrier to entry. This allows plasma technology to be applied in emerging fields requiring close proximity and flexible mobility, such as medical disinfection, wound care, cosmetic skincare, and localized material modification.

[0042] 2. Enhanced discharge stability and controllability. The asymmetric electrode structure composed of "rod-plate" breaks the uniform electric field of traditional symmetric electrodes, making the discharge more inclined to start from the tip of the rod electrode and form a stable stream, effectively suppressing the random distribution phenomenon of micro-discharge channels, thereby improving the consistency and lifetime of discharge.

[0043] It also promotes the efficient generation of active particles. A stronger local electric field can give electrons higher energy. When these high-energy electrons collide with gas molecules (such as air), they will more effectively generate high concentrations of active oxygen / nitrogen species, which is crucial for applications such as disinfection, sterilization, and promoting the healing of biological tissues.

[0044] 3. Employing a three-level inverter topology halves the voltage stress on the switching devices, improving reliability: each main switch only withstands half of the DC bus voltage when turned off. This allows for the selection of power devices with lower rated voltages, faster switching speeds, and lower costs, while significantly reducing the risk of breakdown due to excessive voltage stress. Simultaneously, the output voltage of the three-level topology jumps from one level to two levels, producing a stepped waveform that is closer to a sine wave. This means a significant reduction in inherent harmonic content, greatly improving output waveform quality and reducing harmonics. This results in a substantial reduction in switching losses, directly extending battery life for battery-powered handheld devices and allowing for higher power output in a smaller form factor.

[0045] The above-disclosed embodiments are merely a few specific examples of the present invention, but the present invention is not limited thereto. Any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A dielectric barrier plasma discharge device, characterized in that, include: Handheld housing, dielectric barrier discharge unit Element and integrated control board; A handheld housing, comprising a nozzle, a drive motor, a main housing, a front housing of the handle, a drive motor, a fan slot, a rear housing of the handle, a power switch, a centrifugal fan, and a rear housing; A dielectric barrier discharge unit is placed inside the handheld housing and includes a front plate, an anode copper rod, a ceramic plate, a cathode copper plate, and a fixing plate. An integrated control board is placed inside the handheld housing and connected to the dielectric barrier discharge unit. Its positive line is connected to the anode copper rod of the dielectric barrier discharge unit, and its negative line is connected to the cathode copper sheet of the dielectric barrier discharge unit.

2. The dielectric barrier plasma discharge device according to claim 1, characterized in that, The handheld housing is configured to enable portable handheld operation of the device and plasma generation functions.

3. The dielectric barrier plasma discharge device according to claim 1, characterized in that, In the dielectric barrier discharge unit, the ceramic sheet covers the surface of the cathode copper sheet, and the anode copper rod and the cathode copper sheet covered by the ceramic sheet together form a parallel discharge structure.

4. The dielectric barrier plasma discharge device according to claim 1, characterized in that, The main power circuit of the integrated control board is a full-bridge three-level inverter topology circuit.

5. The dielectric barrier plasma discharge device according to claim 1, characterized in that, The control algorithm used for the main power circuit in the integrated control board is an active disturbance rejection control closed-loop algorithm.

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