Microwave plasma torch gas conversion apparatus based on waveguide resonator

Abstract

The utility model relates to the field of microwave plasma technology, and concretely relates to microwave plasma torch gas conversion device based on waveguide resonant cavity, and the above structure of the utility model is mainly including waveguide cavity and quartz tube, and the quartz tube is arranged in the waveguide cavity, the section of quartz tube in the waveguide cavity is provided with expansion part, and the cross-sectional area of expansion part is greater than the cross-sectional area of non-expansion part of quartz tube. Through the above structure, in the microwave plasma reactor, the quartz tube is centrally provided with the expanded structure area, namely the expansion part, and after the gas is admitted, annular airflow is formed in the expansion area of expansion part, the time of reaction gas being ionized into plasma is significantly prolonged, namely the reaction time is significantly prolonged, which is favorable for improving the reaction conversion efficiency. Moreover, the expansion area provides good conditions for the placement of catalyst, realizes the effective coupling of plasma and catalyst, and enhances the synergistic catalysis effect.

Description

Technical Field

[0001] This utility model relates to the field of microwave plasma technology, and more specifically, to a microwave plasma torch gas conversion device based on a waveguide resonant cavity. Background Technology

[0002] Microwave plasma is characterized by high electron density, high efficiency, and high electron temperature. Therefore, it has wide applications in surface treatment, chemical engineering, and materials processing. However, existing plasma torches used for gas conversion typically have low efficiency.

[0003] Microwave plasma vapor chemical reactions (MPCR) refer to highly efficient gas-phase chemical reaction processes carried out in a microwave-excited plasma environment. This technology provides high-energy electrons, active free radicals, and high-density ions (electron density up to 1.0 × 10⁻⁶). 18 pcs / m 3 Microwave plasma technology enables reactions to proceed efficiently under low temperature, low pressure, or ambient pressure conditions, significantly improving reaction rates and energy efficiency. Compared to traditional electric arc or radio frequency plasma, microwave plasma systems eliminate the need for electrode design, effectively avoiding sputtering contamination and improving product purity, making them particularly suitable for chemical reactions and other fields requiring high cleanliness. The microwave plasma torch (MPT), as a typical device, achieves efficient ionization by directly coupling microwave energy into the working gas. MPTs can operate at ambient pressure, producing highly uniform plasma. Furthermore, the flexible working gas options of MPTs, including argon, nitrogen, oxygen, and even air, allow for the customization of plasma characteristics for specific applications, enabling effective application in plasma chemistry. This flexibility allows microwave plasma technology to meet the needs of waste gas treatment and catalytic reactions such as ammonia synthesis, carbon dioxide reduction, and hydrogen production. Therefore, microwave plasma has wide applications in surface treatment, chemical engineering, and materials processing. However, existing plasma torches used for gas conversion typically have low efficiency. Utility Model Content

[0004] The purpose of this invention is to provide a microwave plasma torch gas conversion device based on a waveguide resonant cavity, in order to solve the problem of low efficiency of plasma torches for gas conversion in the prior art.

[0005] This utility model is achieved through the following technical solution:

[0006] A microwave plasma torch gas conversion device based on a waveguide resonant cavity includes a waveguide cavity and a quartz tube, wherein the quartz tube is disposed in the waveguide cavity.

[0007] The section of the quartz tube located within the waveguide cavity is provided with an expansion section, the cross-sectional area of ​​which is larger than the cross-sectional area of ​​the non-expansion section of the quartz tube.

[0008] Preferably, the expanded portion is cylindrical.

[0009] Preferably, the waveguide cavity includes a frame and a sliding short-circuit panel, the sliding short-circuit panel being slidably connected to one side of the frame.

[0010] Preferably, the frame is provided with a limiting slide rail, and the sliding short-circuit panel moves on the limiting slide rail.

[0011] Preferably, the waveguide cavity has through holes on both sides for the quartz tube to pass through at both ends.

[0012] Preferably, the non-expansion portion of the quartz tube has a cylindrical structure.

[0013] Preferably, the two end faces of the expansion portion are provided with arc-shaped chamfers between the two end faces and the side faces.

[0014] Preferably, the expansion portion is located in the middle of the waveguide cavity.

[0015] The technical solution of this utility model has at least the following advantages and beneficial effects:

[0016] The structure of this invention mainly includes a waveguide cavity and a quartz tube, with the quartz tube disposed within the waveguide cavity. An expansion section is provided in the segment of the quartz tube within the waveguide cavity, and the cross-sectional area of ​​the expansion section is larger than the cross-sectional area of ​​the non-expansion section of the quartz tube. Through this structure, in the microwave plasma reactor, the quartz tube has an enlarged structural region in its center, i.e., the expansion section. After gas intake, an annular airflow structure is formed in the expansion region of the expansion section, significantly extending the time for the reactant gas to be ionized into plasma, thus significantly extending the reaction time and improving the reaction conversion efficiency. Furthermore, the expanded region provides favorable conditions for catalyst placement, achieving effective coupling between plasma and catalyst, and enhancing the synergistic catalytic effect. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the working process of this utility model;

[0020] Figure 3 This is a schematic diagram of the quartz tube of this utility model;

[0021] Figure 4 This is a schematic diagram of the structure of the sliding short-circuit panel of this utility model.

[0022] Icons: 1-quartz tube, 2-waveguide cavity, 3-sliding short-circuit panel, 4-limiting slide rail. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Please refer to Figures 1-3 The present invention provides a microwave plasma torch gas conversion device based on a waveguide resonant cavity, comprising a waveguide cavity 2 and a quartz tube 1, wherein the quartz tube 1 is disposed within the waveguide cavity 2;

[0025] Specifically, the expansion part is cylindrical, and the length of the expansion part is 45 mm. The inner diameter of the non-expansion part is 10 mm and the outer diameter is 12 mm.

[0026] The section of the quartz tube 1 located within the waveguide cavity 2 is provided with an expansion section, the cross-sectional area of ​​which is larger than the cross-sectional area of ​​the non-expansion section of the quartz tube 1. In this embodiment, the cross-sectional area is the cross-section of the quartz tube 1, which is a circular surface area. The purpose of the expansion section is to form a structure with an enlarged volume in the middle of the quartz tube 1.

[0027] Secondly, the non-expansion part of the quartz tube 1 is a cylindrical structure, the inside of the quartz tube 1 is hollow, and the expansion part is located in the middle of the waveguide cavity 2.

[0028] More specifically, through holes are provided on both sides of the waveguide cavity 2 for the two ends of the quartz tube 1 to pass through, that is, the non-expansion part of the quartz tube 1 is connected to the waveguide cavity 2 to fix the quartz tube 1.

[0029] The structure of this invention mainly includes a waveguide cavity 2 and a quartz tube 1, with the quartz tube 1 disposed within the waveguide cavity 2. An expansion section is provided in the section of the quartz tube 1 within the waveguide cavity 2, and the cross-sectional area of ​​the expansion section is larger than the cross-sectional area of ​​the non-expansion section of the quartz tube 1. Through this structure, in the microwave plasma reactor, the quartz tube 1 has an enlarged structural region in its center, i.e., the expansion section. After gas intake, an annular airflow structure is formed in the expansion region of the expansion section, significantly extending the time for the reactant gas to be ionized into plasma, thus significantly extending the reaction time and improving the reaction conversion efficiency. Furthermore, the expanded region provides favorable conditions for catalyst placement, achieving effective coupling between plasma and catalyst, and enhancing the synergistic catalytic effect.

[0030] Secondly, an arc-shaped chamfer is provided between the two end faces and the side faces of the expansion section, that is, a chamfer structure is provided between the two bottom faces and the side faces of the cylinder, so that the gas can flow along the chamfer and the gas flow is more regular.

[0031] The device is located in a rectangular waveguide resonant cavity TE 101 The device efficiently excites and sustains plasma under mode. By expanding the plasma excitation region within the resonant cavity, it achieves efficient plasma excitation and sustainment. In this study, various gases were used to conduct experiments at microwave powers ranging from 300 to 1000 W. Experimental data show that, under the combined adjustment of a three-pin tuner, the larger excitation region within the waveguide allows the plasma to effectively absorb microwaves, achieving a microwave energy efficiency of over 99%.

[0032] Furthermore, the expanded structure, completely occupied by the region after plasma excitation, helps improve the absorption and dissipation efficiency of microwave energy in the plasma, thereby enhancing the microwave utilization rate of the entire system. The device operates at microwave power of 300-100W and a temperature of 800℃-1200℃, making it suitable for most industrial production applications.

[0033] In another embodiment, the waveguide cavity 2 includes a frame and a sliding short-circuit panel 3, which is slidably connected to one side of the frame. This allows the resonant frequency of the cavity to be adjusted by moving the sliding short-circuit panel 3, thereby widening the operating bandwidth of the device.

[0034] In addition, the frame is equipped with a limiting slide rail 4, and the sliding short-circuit panel 3 moves on the limiting slide rail 4, making the movement of the sliding short-circuit panel 3 smoother.

[0035] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A microwave plasma torch gas conversion apparatus based on a waveguide resonator cavity, characterized in that, It includes a waveguide cavity and a quartz tube, wherein the quartz tube is disposed within the waveguide cavity; The section of the quartz tube located within the waveguide cavity is provided with an expansion section, the cross-sectional area of ​​which is larger than the cross-sectional area of ​​the non-expansion section of the quartz tube.

2. The waveguide resonator-based microwave plasma torch gas conversion apparatus of claim 1, wherein, The expansion portion is cylindrical.

3. The waveguide resonator-based microwave plasma torch gas conversion apparatus of claim 1, wherein, The waveguide cavity includes a frame and a sliding short-circuit panel, which is slidably connected to one side of the frame.

4. The waveguide resonator-based microwave plasma torch gas conversion apparatus of claim 3, wherein, The frame is equipped with a limiting slide rail, and the sliding short-circuit panel moves on the limiting slide rail.

5. The microwave plasma torch gas conversion device based on a waveguide resonant cavity according to claim 1, characterized in that, The waveguide cavity has through holes on both sides for the quartz tube to pass through at both ends.

6. The microwave plasma torch gas conversion device based on a waveguide resonant cavity according to claim 1, characterized in that, The non-expansion section of the quartz tube has a cylindrical structure.

7. The microwave plasma torch gas conversion device based on a waveguide resonant cavity according to claim 1, characterized in that, The expansion section has arc-shaped chamfers between its two end faces and side faces.

8. The microwave plasma torch gas conversion device based on a waveguide resonant cavity according to claim 1, characterized in that, The expansion portion is located in the middle of the waveguide cavity.

Images