Spiral electric field-flow field synergistic plasma generation system

Abstract

A spiral electric field-flow field synergistic plasma generation system comprises a coaxial cylindrical discharge tube, an air inlet is formed in the lower end of the coaxial cylindrical discharge tube, an air outlet is formed in the upper end of the coaxial cylindrical discharge tube, an inner electrode is arranged in the coaxial cylindrical discharge tube, a plurality of corona discharge needles are connected to the surface of the inner electrode, and an outer electrode is arranged on the cylindrical wall surface of the coaxial cylindrical discharge tube. A spiral baffle plate is arranged in the coaxial cylindrical discharge tube, and a protruding discharge wall surface is arranged at the position, opposite to the corona discharge needle, of the cylindrical inner wall of the coaxial cylindrical discharge tube; when the inner electrode is excited by high voltage, corona discharge is formed between the corona discharge needle and the protruding discharge wall face, corona areas are evenly distributed between the screw pitches of the spiral baffle plate, pollutants enter the plasma generation system, and the pollutants are influenced by the spiral baffle plate to do directional spiral motion. By means of the spiral electric field-flow field cooperative structure, the length of the motion trail of the pollutants to be treated in the plasma generation system is increased by 20 times or above, and the pollutant treatment effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of plasma discharge, and particularly relates to a spiral electric field-flow field collaborative plasma generation system. Background Art

[0002] Low-temperature plasma technology has extremely strong potential advantages in the field of environmental pollution treatment due to its high efficiency and broad spectrum. Plasma (ionized gas) can be generated by high-voltage discharge (such as corona discharge, dielectric barrier discharge, etc.) or high-frequency electromagnetic fields exciting gases (such as air, inert gases, etc.), which contains a large number of high-energy electrons, ions, free radicals (such as ·OH, ·O, O3, etc.) and excited state molecules. The principle of treating pollutants by low-temperature plasma technology is as follows: on the one hand, high-energy electrons can directly bombard pollutant molecules, break chemical bonds (such as C-H, C-C, C-O bonds), and decompose them into small molecules or atoms; on the other hand, active free radicals react with pollutants through oxidation, reduction or cleavage reactions, and finally convert into harmless substances such as CO2, H2O, N2, etc.

[0003] The high-energy region of plasma discharge is concentrated at the electrode tip with a smaller radius of curvature, and this region is the core area for treating organic waste, only accounting for 20% of the discharge area. The tubular plasma generation device places the inner electrode in the reaction tube, and the high-voltage motor is arranged outside the tube. The form of its inner electrode is diverse. In existing applications, there are cylindrical coaxial type and needle tip type, such as the patent application named "A Visual Air Purifier with Fast Diffusion and Decomposition Function" (Publication No.: CN118423787A) and the patent application named "A Fan Coil Type Plasma Air Disinfection Device" (Publication No.: CN216481345U). Only the tubular generation device effectively limits the movement trajectory of pollutants in the discharge space, increases the contact probability between pollutants and the high-energy discharge region, but it is still limited to the linear movement mode of pollutants in the pipeline. Under the action of high-speed airflow, the short reaction time of pollutants also limits its removal efficiency. Summary of the Invention

[0004] In order to overcome the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a spiral electric field-flow field collaborative plasma generation system, which increases the contact frequency between pollutants and high-energy ions, improves the discharge uniformity; increases the movement trajectory of pollutants, provides sufficient reaction time for complex physical and chemical changes, and improves the treatment effect on organic waste; improves the space utilization rate of the plasma generation device, making it possible to apply low-temperature plasma in environments with strict space requirements (such as air purification in cars and aircraft).

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A helical electric field-flow field synergy plasma generation system includes a coaxial cylindrical discharge tube. The lower end of the coaxial cylindrical discharge tube is an air inlet 1, and the upper end is an air outlet 2. An inner electrode 3 is provided inside the coaxial cylindrical discharge tube. A number of corona discharge needles 4 are connected to the surface of the inner electrode 3. The cylindrical wall surface of the coaxial cylindrical discharge tube is an outer electrode 5. A spiral baffle 6 is arranged inside the coaxial cylindrical discharge tube. A convex discharge wall surface 7 is provided at the position on the inner wall of the coaxial cylindrical discharge tube opposite to the corona discharge needles 4.

[0007] The coaxial cylindrical discharge tube is a hollow cylinder made of stainless steel, and other components of the entire plasma generation system are encapsulated in the hollow cylinder.

[0008] The inner electrode 3 is externally connected to the high-voltage end of the power supply. A number of identical corona discharge needles 4 are arranged on its surface with a spiral axial offset. The material of the corona discharge needles 4 is metal nickel.

[0009] The outer electrode 5 is grounded, and a part of its inner surface protrudes to form the discharge wall surface 7. The material of the outer electrode 5 is stainless steel.

[0010] The material of the spiral baffle 6 is insulating ceramic.

[0011] The corona discharge needles 4 are designed with a thorn-shaped array arrangement.

[0012] The cross-section of the corona discharge needles 4 is in a flat triangular structure, so that the corona discharge needles 4 have a small curvature radius (within 1 mm).

[0013] The spiral baffle 6 is closely attached to the inner wall of the coaxial cylindrical discharge tube and keeps a distance from the corona discharge needles 4.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. Through the arrangement of the spiral baffle in the present invention, pollutants spiral upward in the device under the action of the air flow, increasing the movement trajectory length of the pollutants, providing sufficient reaction time for complex physical and chemical changes, and improving the treatment effect on organic waste.

[0016] 2. The thorn-shaped corona discharge needles on the inner electrode of the present invention are arranged between the pitches of the spiral baffle, so that the plasma density is increased by at least two times, improving the plasma energy under the same conditions, and effectively solving the problems of small plasma density generated by traditional direct discharge electrodes and low efficiency of removing pollutants and sterilization and disinfection; compared with stainless steel, nickel can effectively prevent the oxidation and corrosion of organic pollutants on the premise of ensuring the discharge effect.

[0017] 3. In the present invention, the outer electrode forms a discharge wall at the position facing the corona discharge needle with an inward convex part, reducing the effective distance between the corona discharge needle electrode and the wall surface to improve the discharge effect. At the same time, it also has a certain optimization effect on the internal flow field of the pipeline, thereby improving the pollutant removal efficiency.

[0018] 4. Under the synergistic effect of the spiral electric field - flow field in the present invention, the space utilization rate of the plasma generating device is improved, making it possible to apply low-temperature plasma in environments with strict space requirements (such as air purification in automobiles and aircraft). BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an overall view of an embodiment of the present invention.

[0020] Figure 2 It is a top view of an embodiment of the present invention.

[0021] Figure 3 It is a front view of an embodiment of the present invention.

[0022] Figure 4 It is a side view of an embodiment of the present invention.

[0023] Figure 5 It is a sectional view of an embodiment of the present invention.

[0024] Figure 6 It is a view of the convex discharge wall surface of an embodiment of the present invention.

[0025] In the figure: 1 is the air inlet; 2 is the air outlet; 3 is the inner electrode; 4 is the discharge nickel needle; 5 is the outer electrode; 6 is the spiral baffle; 7 is the convex discharge wall surface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The present invention will be further described below in conjunction with the embodiments and the drawings.

[0027] Embodiment: Referring to Figure 1 - Figure 6 , a spiral electric field - flow field synergistic plasma generating system includes a coaxial cylindrical discharge tube. The lower end of the coaxial cylindrical discharge tube is the air inlet 1, the upper end is the air outlet 2. Inside the coaxial cylindrical discharge tube, there is an inner electrode 3, and a number of corona discharge needles 4 are connected to the surface of the inner electrode 3. The cylindrical wall surface of the coaxial cylindrical discharge tube is the outer electrode 5. A spiral baffle 6 is arranged inside the coaxial cylindrical discharge tube, and a convex discharge wall surface 7 is provided at the position where the inner wall of the coaxial cylindrical discharge tube faces the corona discharge needle 4;

[0028] The coaxial cylindrical discharge tube is a hollow cylinder made of stainless steel. All other components of the entire plasma generating system are encapsulated in the hollow cylinder to ensure the sealing of the device, promoting the degradation and purification of the pollutants to be treated inside the system without being interfered by external factors;

[0029] The inner electrode 3 is externally connected to the high-voltage terminal of the power supply. A number of identical corona discharge needles 4 are arranged axially and staggeredly on its surface. The material of the corona discharge needles 4 is nickel. Compared with stainless steel, nickel can effectively prevent the oxidation and corrosion of organic pollutants while ensuring the discharge effect.

[0030] The outer electrode 5 is grounded. Part of its inner surface bulges to form a protruding discharge wall surface 7, which reduces the effective distance between the corona discharge needle electrode and the wall surface, thereby improving the discharge effect. At the same time, it also has a certain optimization effect on the internal flow field of the pipeline, thus improving the pollutant removal efficiency. The material of the outer electrode 5 is stainless steel.

[0031] The material of the spiral baffle 6 is smooth-surface insulating ceramic, which can effectively reduce the accumulation of pollutants on the surface of the spiral baffle on the premise of corrosion resistance and without affecting the discharge effect.

[0032] The corona discharge needles 4 are arranged in a barbed type array, which makes the plasma density increase by at least twice, improves the plasma energy under the same conditions, and effectively solves the problems of small plasma density generated by traditional direct discharge electrodes and low efficiency of pollutant removal and disinfection.

[0033] The cross-section of the corona discharge needle 4 is in a flat triangular structure, which makes the corona discharge needle 4 have a small curvature radius (within 1 mm), thereby ensuring a high free radical yield and space charge density of the corona discharge and promoting the effective degradation of the pollutants to be treated.

[0034] The spiral baffle 6 is closely attached to the inner wall of the coaxial cylindrical discharge tube and keeps a distance from the corona discharge needles 4, so that the pollutants to be treated move in a spiral motion in the coaxial cylindrical discharge tube. At the same time, the high-energy region of the corona discharge is concentrated between the pitches of the spiral baffle 6, effectively increasing the frequency and time of contact between the pollutants to be treated and free radicals and high-energy electrons during the spiral motion, and promoting their effective degradation.

[0035] The working principle of the present invention is as follows: Under the high-voltage excitation of the inner electrode 3, a corona discharge is formed between the corona discharge needles 4 and the protruding discharge wall surface 7, and the corona region is evenly distributed between the pitches of the spiral baffle 6. At this time, the pollutants to be treated enter the plasma generation system under a certain wind force and will perform a directional spiral motion under the influence of the spiral baffle 6. The spiral electric field-flow field cooperative structure makes the movement trajectory length of the pollutants to be treated in the plasma generation system increase by more than 20 times. At the same time, the high-concentration plasma region is concentrated between the pitches of the spiral baffle 6, providing sufficient reaction time for complex physical and chemical changes, greatly improving the treatment effect on pollutants; at the same time, it improves the space utilization rate of the plasma generation system and meets the space requirements of low-temperature plasma.

[0036] The parameters of this embodiment are shown in Table 1 below.

[0037] Table 1

[0038] Cylinder radius / m 0.2 Cylinder length / m 0.5 Needle curvature radius / m 0.001 Corona discharge needle length / m 0.03 Discharge gap distance / m 0.05 Thread inclination angle / ° 25 Pitch / m 0.045 <![CDATA[Initial flow velocity / m·s -1 > 5 Discharge voltage / kV 20

[0039] In this embodiment, the pollutants enter the spiral plasma generator at a speed of 5 m / s and move a distance of 12.56 m inside the generator. Compared with the DC mode (0.5 m), it is increased by about 25 times, greatly increasing the movement trajectory of the pollutants, providing sufficient reaction time for complex physical and chemical changes, and improving the treatment effect on organic waste.

[0040] The above-described embodiments are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those skilled in the art to the technical solutions of the present invention all fall within the protection scope determined by the claims of the present invention.

Claims

1. A spiral electric field-flow field coordinated plasma generation system, comprising a coaxial cylindrical discharge tube, characterized in that: The lower end of the coaxial cylindrical discharge tube is an air inlet (1), the upper end of the coaxial cylindrical discharge tube is an air outlet (2), an inner electrode (3) is arranged inside the coaxial cylindrical discharge tube, a plurality of corona discharge needles (4) are connected to the surface of the inner electrode (3), the cylindrical wall surface of the coaxial cylindrical discharge tube is an outer electrode (5), a spiral baffle (6) is arranged inside the coaxial cylindrical discharge tube, and a convex discharge wall surface (7) is provided at a position where the cylindrical inner wall of the coaxial cylindrical discharge tube and the corona discharge needles (4) are opposite.

2. The plasma generating system according to claim 1, characterized in that: The coaxial cylindrical discharge tube is a hollow cylinder made of stainless steel, and other components of the entire plasma generation system are encapsulated in the hollow cylinder.

3. The plasma generating system according to claim 1, characterized in that: The inner electrode (3) is externally connected to the high voltage end of a power source, and a plurality of identical corona discharge needles (4) are arranged on the surface of the inner electrode in a spiral axially staggered manner. The corona discharge needles (4) are made of metal nickel.

4. The plasma generating system according to claim 1, characterized in that: The outer electrode (5) is grounded, and a portion of its inner surface is raised to form a discharge surface. The outer electrode (5) is made of stainless steel.

5. The plasma generating system according to claim 1, characterized in that: The spiral baffle (6) is made of insulating ceramic.

6. The plasma generating system according to claim 1, characterized in that: The corona discharge needles (4) are arranged in a thorn-shaped array.

7. The plasma generating system according to claim 1, characterized in that: The cross section of the corona discharge needle (4) is a flat triangular structure, so that the corona discharge needle (4) has a small curvature radius within 1 mm.

8. The plasma generating system according to claim 1, characterized in that: The spiral baffle (6) is in close contact with the inner wall of the coaxial cylindrical discharge tube and maintains a distance from the corona discharge needle (4).

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