A general-purpose multi-gas AC arc plasma generator

Abstract

This invention discloses a universal multi-gas AC arc plasma generator, relating to the field of electrical engineering technology. It includes three arc channels whose longitudinal axes of symmetry intersect at a solid angle. Each arc channel consists of an electrode unit, a middle section, and an outlet. The middle section and outlet are electrically connected. All three arc channels are integrated into a unified nozzle assembly. The electrode unit includes an electrode block body, a through-insulator, an inlet pipe, an electrode support, and electrodes. The electrodes are housed within the electrode support and can move along the longitudinal axis of symmetry of the arc channels. This plasma generator has the ability to adjust the arc channel length and switch operating modes, and can operate stably across a power range from low to high power and a gas flow rate from low to high, solving the problem of narrow operating condition adaptability of existing equipment.

Description

Technical Field

[0001] This invention relates to the field of electrical engineering technology, specifically a general-purpose multi-gas AC arc plasma generator. Background Technology

[0002] In the field of electrical engineering, thermal plasma, due to its high energy density and wide temperature range, is widely used in industrial applications such as materials synthesis, waste treatment, and surface modification. Currently, the core equipment for obtaining thermal plasma is an AC plasma generator. The known structures of AC plasma generators are as follows:

[0003] Known patent WO2013019630A1 discloses a device for generating thermal plasma using nitrogen, carbon dioxide, hydrogen, or inert gas. Known patents RU2680318C1 and RU2775363C1 disclose devices for generating thermal plasma using air, nitrogen, carbon dioxide, argon, and mixtures of these gases with hydrocarbons. However, the electrode node manufacturing process of the above devices is complex, making it impossible to transport multi-component mixed gases through the electrode nodes. Furthermore, the control system and plasma forming gas supply system need to be directly installed near the plasma generator, which makes it impossible to guarantee normal operation under low gas flow conditions and to adjust the power of the plasma generator and the flow range of the plasma forming gas within a wide range.

[0004] Patent RU2231936C1 discloses a high-voltage AC arc plasma generator device for generating thermal plasma, using air, carbon dioxide, nitrogen, and argon as plasma forming media. The Institute of Electrophysics and Electric Power of the Russian Academy of Sciences has also developed a high-voltage AC arc plasma generator structure, the parameters of which have been disclosed in scientific papers and dissertations. This plasma generator is used to generate thermal plasma, employing air, nitrogen, argon, carbon dioxide, water vapor, gaseous hydrocarbons, or individual or mixed gases as plasma forming media. However, the continuous operating time of these devices is relatively short, and their power limit is low, failing to meet the needs of industrial applications.

[0005] Based on this, a general-purpose multi-gas AC arc plasma generator is now provided, which can eliminate the drawbacks of existing technical solutions. Summary of the Invention

[0006] The purpose of this invention is to provide a universal multi-gas AC arc plasma generator to solve the problems of narrow power and gas compatibility range, short continuous working time and low power upper limit in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A general-purpose multi-gas AC arc plasma generator includes three arc channels, each arc channel being a spatial region within the plasma generator where an arc exists. The longitudinal axes of symmetry of the three arc channels intersect at a solid angle α, the solid angle being 0–90°. Each arc channel consists of an electrode unit, a middle section of the arc channel, and an arc channel outlet. The middle section of the arc channel and the arc channel outlet are electrically connected. The middle sections and outlets of the three arc channels are all integrated within a unified nozzle assembly.

[0009] The electrode unit includes an electrode block body, a through insulator, an air inlet pipe, an electrode support, and an electrode. The electrode is electrically connected to the electrode support and is disposed inside the electrode support, and can move along the longitudinal axis of symmetry of the arc channel.

[0010] Preferably, the electrode block body is a cylindrical rotating body made of metal, and the electrode block body has a first thickened part on the side near the unified nozzle assembly.

[0011] Preferably, the through insulator is a cylindrical structure made of insulating material. The through insulator includes a first through insulator and a second through insulator. The first through insulator is fixed inside the electrode block body, and the second through insulator is fixed outside the electrode block body. The second through insulator and the electrode block body can move along the longitudinal axis of symmetry of the arc channel. The second through insulator is slidably disposed inside the unified nozzle assembly.

[0012] Preferably, the air inlet pipe is used to introduce plasma forming gas into the electrode unit and form a vortex. The air inlet pipe includes a first air inlet pipe and a second air inlet pipe. The gas delivery direction of the first air inlet pipe is tangentially arranged relative to the inner surface of the electrode block body. The second air inlet pipe is disposed on the second through insulator. The gas delivery direction of the second air inlet pipe is tangentially arranged relative to the guide surface of the unified nozzle assembly.

[0013] Preferably, the electrode support is made of metal material and is fixedly installed inside the first through-insulator. The electrode support has a second thickened part on the side near the first thickened part. The electrode support has a groove inside and a first sealing element and a second sealing element are respectively provided on both sides of the groove. The end of the electrode support is connected to a feeding mechanism, which is used to drive the electrode to move along the longitudinal axis of symmetry of the arc channel toward the outlet of the arc channel.

[0014] Preferably, the groove, together with the first seal, the second seal, and the electrode side, forms a cooling jacket, and the unified nozzle assembly consists of three arc channels and a cooling jacket.

[0015] Preferably, the electrode is a cylindrical structure with smooth sidewalls, and the electrode is made of a conductive material.

[0016] Preferably, the first thickened portion, together with the front wall of the second through-insulator, the second air inlet pipe, and the guide surface of the unified nozzle assembly, constitutes a first vortex chamber. The first vortex chamber serves as the area for igniting an electric arc between the electrode block body and the guide surface of the unified nozzle assembly. The second thickened portion, together with the front wall of the first through-insulator and the first air inlet pipe, constitutes a second vortex chamber. The second vortex chamber serves as the area for igniting an electric arc between the electrode support and the inner surface of the electrode block body.

[0017] Preferably, the plasma generator is powered by a high-voltage three-phase AC power grid, and the plasma forming medium of the plasma generator is a single gas or a mixture of any two or more gases, including air, nitrogen, argon, helium, carbon dioxide, hydrogen, gaseous and vaporous hydrocarbons, and hydrogen sulfide.

[0018] Preferably, the length adjustment of the arc channel is L, and the plasma generator has two operating modes:

[0019] Working mode 1: If the length adjustment value L is greater than zero, in this working mode, the electrode block body and the unified nozzle assembly are electrically insulated. Each arc channel includes a first air inlet pipe, a second air inlet pipe and two discharge gaps, which is suitable for high power and high gas flow conditions.

[0020] Operating Mode 2: If the length adjustment value L is zero, in this operating mode, the outer conical surface of the first thickened part is tightly joined with the inner conical surface of the arc channel in the unified nozzle assembly, so that the electrode block body and the unified nozzle assembly form an electrical connection. The inner surface of the electrode block body and the inner surface of the unified nozzle assembly form an arc channel, and block the introduction of gas through the second air inlet pipe. Each arc channel retains only one discharge gap and the first air inlet pipe, which is suitable for high power, low power and low gas flow conditions.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] This invention provides a universal multi-gas AC arc plasma generator with adjustable arc channel length, which improves the continuous operating life of the plasma generator over a wide power range. The generator can operate stably under various power ranges (from low to high power) and gas flow rates (from low to high flow rates) by switching between two operating modes. It is compatible with single or mixed gases such as air, nitrogen, and argon as the plasma forming medium, solving the problem of narrow operating range adaptability of existing equipment. Furthermore, the generator features a dual vortex chamber and dual inlet pipes, which efficiently form stable vortices from multiple gases, ensuring uniform mixing and full ionization of complex gas components, thereby improving stability and compositional uniformity. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 This is a schematic diagram of the electrode unit of the present invention.

[0025] Figure 3 This is a schematic diagram of the arc channel structure of the present invention.

[0026] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle.

[0027] Figure 5 This is a schematic diagram of the first working mode of the present invention.

[0028] Figure 6 This is a schematic diagram of the second working mode of the present invention.

[0029] Figure 7 This is a schematic diagram of a short electric arc within the arc channel at the initial moment of the present invention.

[0030] Figure 8 This is a schematic diagram of the short arc elongated within the arc channel of the present invention.

[0031] Figure 9 This is a schematic diagram of the arc output terminal of the present invention after it is closed.

[0032] Figure reference numerals: Electrode unit 10, Electrode block body 11, First thickened part 111, Through insulator 12, First through insulator 121, Second through insulator 122, Air inlet pipe 13, First air inlet pipe 131, Second air inlet pipe 132, Electrode support 14, Second thickened part 141, Groove 142, First seal 143, Feeding mechanism 144, Second seal 145, Electrode 15, Arc channel intermediate section 20, Arc channel outlet 30, Unified nozzle assembly 40. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] In this embodiment, as Figure 1 - Figure 9 As shown, a general-purpose multi-gas AC arc plasma generator includes three arc channels, each being a spatial region within the plasma generator where an arc exists. The longitudinal axes of symmetry of the three arc channels intersect at a solid angle, denoted as α. Figure 1 As shown, the longitudinal symmetry axes of the three arc channels intersect at a point in space, and the included angles formed by each pair of the three axes are all α, with the solid angle ranging from 0 to 90°. The three axes are axially symmetric. The arc channel consists of an electrode unit 10, an arc channel middle section 20, and an arc channel outlet 30. The arc channel middle section 20 and the arc channel outlet 30 are electrically connected. The arc channel middle section 20 and the arc channel outlet 30 of the three arc channels are all integrated into a unified nozzle assembly 40. The middle section and outlet section of the three arc channels are highly integrated into a unified nozzle assembly 40, which has a compact structure, avoids complex multi-body docking and calibration problems, and reduces complexity.

[0035] The electrode unit 10 includes an electrode block body 11, a through insulator 12, an air inlet pipe 13, an electrode support 14, and an electrode 15. The electrode 15 is electrically connected to the electrode support 14, and the electrode 15 is disposed inside the electrode support 14 and can move along the longitudinal axis of symmetry of the arc channel.

[0036] Specifically, this plasma generator can operate within a wide power range and under various plasma-forming gas compositions, and has the ability to flexibly adjust parameters to adapt to different application scenarios. It also features a long continuous operating life and a simple control system. This AC plasma generator includes three arc channels, each representing a set of components within the plasma generator where the arc burns. The electrode block body 11 and the second through-insulator 122 are fixedly connected to form a whole, and can move along the guide surface of the unified nozzle assembly 40. The sliding direction is parallel to the longitudinal axis of symmetry of the arc channel, thereby increasing or decreasing the length of the arc channel. At the limit position corresponding to the shortest arc channel length, the aforementioned components form an electrical connection with each other. Specifically, when the arc channel is at its shortest length (L=0), the electrode block body 11 forms a rigid contact with the unified nozzle assembly 40 and achieves an electrical connection. The first thickened portion 111 of the electrode block body 11 is close to the unified nozzle assembly 40, and an outer conical surface is machined on the outer side of the first thickened portion 111. Figure 3 Position a), made of conductive metal (steel, copper, aluminum, etc.), near the arc channel outlet 30, the unified nozzle assembly 40 is machined with an inner conical surface that matches the aforementioned outer conical surface. Figure 3Position b), also made of conductive metal, when L=0, the outer cone surface a and the inner cone surface b are tightly fitted, physically blocking the gap and preventing gas leakage. Electrically, this allows the electrode block body 11 to contact the unified nozzle assembly 40, forming a conductive path. The electric arc ignites in the discharge gap between the second thickened part 141 and the inner surface of the electrode block body 11. When the arc channel is at its shortest length (L=0), the second air intake pipe 132 stops working, and its gas passage is completely blocked. Figure 6 As shown, only the first air intake pipe 131 maintains normal air intake, which is suitable for low gas flow scenarios;

[0037] Among them, such as Figure 2 and Figure 4 As shown, the electrode block body 11 is a cylindrical rotating body made of metal. The electrode block body 11 has a first thickened part 111 on the side near the unified nozzle assembly 40. The metal material is such as steel, copper, aluminum, nickel, etc. The electrode block body 11 has a cooling channel and a cooling jacket inside, and includes fasteners (not shown in the figure) for connecting the structural units. The electrode block body 11 is inserted into the unified nozzle assembly 40 through the second through insulator 122.

[0038] Among them, such as Figure 2 - Figure 4 As shown, the through insulator 12 is a cylindrical structure made of insulating material. The through insulator 12 includes a first through insulator 121 and a second through insulator 122. The first through insulator 121 is fixed inside the electrode block body 11, and the second through insulator 122 is fixed outside the electrode block body 11. The second through insulator 122 and the electrode block body 11 can move along the longitudinal axis of symmetry of the arc channel. The second through insulator 122 is slidably disposed inside the unified nozzle assembly 40.

[0039] Among them, such as Figure 2 - Figure 4 As shown, the air inlet pipe 13 is used to introduce plasma forming gas into the electrode unit 10 and form a vortex. The air inlet pipe 13 includes a first air inlet pipe 131 and a second air inlet pipe 132. The gas delivery direction of the first air inlet pipe 131 is tangentially arranged relative to the inner surface of the electrode block body 11. The second air inlet pipe 132 is disposed on the second through insulator 122. The gas delivery direction of the second air inlet pipe 132 is tangentially arranged relative to the guide surface of the unified nozzle assembly 40.

[0040] Among them, such as Figure 2 - Figure 4As shown, the electrode support 14 is made of metal and is fixedly installed inside the first through-insulator 121. A second thickened portion 141 is provided on the side of the electrode support 14 near the first thickened portion 111. A groove 142 is provided inside the electrode support 14. A first sealing element 143 and a second sealing element 145 are respectively provided on both sides of the groove 142. The two sealing elements are installed between the groove 142 and the side surface of the electrode 15, ensuring a tight fit between them and the side surface of the electrode 15 and the groove 142 of the electrode support 14. This prevents interference with the feeding action of the electrode 15 and blocks the gap between the cooling jacket and the external space. To prevent leakage of cooling medium, the end of the electrode support 14 is connected to a feeding mechanism 144. The feeding mechanism 144 is used to drive the electrode 15 to move along the longitudinal axis of symmetry of the arc channel toward the arc channel outlet 30. The electrode support 14 also includes a coolant inlet and outlet assembly, an electrical power access assembly, and structural fasteners (not shown in the figure). The electrode support 14 and the electrode 15 are electrically insulated from the electrode block body 11. At the same time, the electrode 15 can move axially through the feeding mechanism 144, which can compensate for electrode wear caused by arc erosion in real time, maintain equipment operation without interruption, and extend service life.

[0041] Among them, such as Figure 4 As shown, the groove 142 together with the first seal 143, the second seal 145, and the side of the electrode 15 forms a cooling jacket. The unified nozzle assembly 40 consists of three arc channels and a cooling jacket, and also includes a cooling channel for the electrode block body 11 and fasteners for connecting structural units (not shown in the figure), thereby enabling efficient heat dissipation of the electrode 15 and the core components.

[0042] Among them, such as Figure 2 and Figure 3 As shown, electrode 15 is a cylindrical structure with smooth sidewalls. Electrode 15 is made of conductive material. Electrode 15 is actually a smooth-walled cylinder made of refractory material or its alloy. The conductive material can be copper, copper alloy, steel, aluminum, graphite, tungsten, hafnium, etc.

[0043] Among them, such as Figure 3 and Figure 4 As shown, the first thickened portion 111, together with the front wall of the second through insulator 122, the second air inlet pipe 132, and the guide surface of the unified nozzle assembly 40, constitutes the first vortex chamber. The first vortex chamber is used as the area for igniting the electric arc between the electrode block body 11 and the guide surface of the unified nozzle assembly 40. The second thickened portion 141, together with the front wall of the first through insulator 121 and the first air inlet pipe 131, constitutes the second vortex chamber. The second vortex chamber is used as the area for igniting the electric arc between the electrode support 14 and the inner surface of the electrode block body 11.

[0044] Specifically, the plasma generator is powered by a high-voltage three-phase AC power grid, and the plasma forming medium of the plasma generator is a single gas or any two or more of the following: air, nitrogen, argon, helium, carbon dioxide, hydrogen, gaseous and vaporous hydrocarbons, and hydrogen sulfide.

[0045] Specifically, the length adjustment of the arc channel is L, which is the axial displacement of the electrode block body 11 relative to the unified nozzle assembly 40. When L = 0, the electrode block body 11 is in contact with the unified nozzle assembly 40; when L > 0, the electrode block body 11 separates from the unified nozzle assembly 40. Figure 3 As shown, the second through insulator 122 and the electrode block body 11 can move axially along the guide surface within the unified nozzle assembly 40 to adjust the arc channel length, thereby achieving the switching between high-enthalpy and low-enthalpy plasma modes. Different air inlet pipes 13 are set for the two working modes, which can ensure the uniform delivery of multi-component mixed gas and stabilize the arc shape through airflow regulation, thereby improving the controllability of plasma parameters. This plasma generator has two working modes:

[0046] Working mode 1: If the length adjustment value L is greater than zero, such as Figure 5 As shown, in this working mode, the electrode block body 11 is electrically insulated from the unified nozzle assembly 40. Each arc channel includes a first air inlet pipe 131, a second air inlet pipe 132, and two discharge gaps, which are labeled as c and d. This is suitable for high-power and high-gas-flow conditions, and the length of the arc channel can be adjusted according to the technical conditions of the plasma generator.

[0047] Working mode two: If the length adjustment value L is equal to zero, such as Figure 6 As shown, in this working mode, the outer conical surface of the first thickened part 111 is tightly joined with the inner conical surface of the arc channel in the unified nozzle assembly 40. The outer conical surface of the first thickened part 111 is designated as a, and the inner conical surface of the arc channel in the unified nozzle assembly 40 is designated as b, so that the electrode block body 11 and the unified nozzle assembly 40 form an electrical connection. The inner surface of the electrode block body 11 and the inner surface of the unified nozzle assembly 40 form an arc channel, and block the introduction of gas through the second air inlet pipe 132. Each arc channel retains only one discharge gap and the first air inlet pipe 131. The discharge gap is marked as e, which is suitable for high power, low power and low gas flow conditions.

[0048] In use, plasma-generating gas is delivered to each inlet pipe 13 and powered by a high-voltage three-phase AC power grid (e.g., 10000V). Each phase is connected to the electrode support 14, and the electrode support 14 is electrically connected to the electrode 15. Under the action of the electric field, short arcs are ignited at each discharge gap. Initially, there are two short arcs in each arc channel. The first short arc burns between the second thickened part 141 on one side of the electrode support 14 and the inner surface of the electrode block body 11. The second short arc is ignited between the first thickened part 111 of the electrode block body 11 and the arc channel guide surface inside the unified nozzle assembly 40. Initially, there are a total of six short arcs inside the plasma generator, such as... Figure 7 As shown, under the influence of electromagnetic and aerodynamic forces, each short electric arc gradually elongates, as... Figure 8 As shown, the two arc segments within the same arc channel then merge into one arc. The arc attachment point on the electrode support 14 side transfers to the front end face of the electrode 15, while the arc output end slides along the internal channel surface of the unified nozzle assembly 40 to the arc channel outlet 30. Afterwards, the arc output ends generated by each arc channel complete closure in the space behind the unified nozzle assembly 40, as... Figure 9 As shown.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A general-purpose multi-gas AC arc plasma generator, characterized in that, It includes three arc channels, which are spatial regions inside the plasma generator where an electric arc exists. The longitudinal symmetry axes of the three arc channels intersect at a solid angle, which is set as α. The value range of the solid angle is 0 < α ≤ 90°. The arc channel is composed of an electrode unit (10), an arc channel middle section (20), and an arc channel outlet (30). The arc channel middle section (20) and the arc channel outlet (30) are electrically connected. The arc channel middle section (20) and the arc channel outlet (30) of the three arc channels are all integrated in a unified nozzle assembly (40). The electrode unit (10) includes an electrode block body (11), a through insulator (12), an air inlet pipe (13), an electrode support (14), and an electrode (15). The electrode (15) is electrically connected to the electrode support (14). The electrode (15) is located inside the electrode support (14) and can move along the longitudinal axis of symmetry of the arc channel. The electrode block body (11) is a cylindrical rotating body made of metal, and the electrode block body (11) has a first thickened part (111) on the side near the unified nozzle assembly (40). The length of the arc channel is adjustable by L, and the plasma generator has two operating modes: Working mode 1: If the length adjustment value L is greater than zero, in this working mode, the electrode block body (11) and the unified nozzle assembly (40) are electrically insulated. Each of the arc channels includes a first air inlet pipe (131), a second air inlet pipe (132) and two discharge gaps, which is suitable for high power and high gas flow conditions. Working mode 2: If the length adjustment value L is equal to zero, in this working mode, the outer conical surface of the first thickened part (111) is tightly joined with the inner conical surface of the arc channel in the unified nozzle assembly (40), so that the electrode block body (11) and the unified nozzle assembly (40) form an electrical connection. The inner surface of the electrode block body (11) and the inner surface of the unified nozzle assembly (40) form an arc channel, and block the introduction of gas through the second air inlet pipe (132). Each arc channel retains only one discharge gap and the first air inlet pipe (131), which is suitable for high power, low power and low gas flow conditions. The through insulator (12) is a cylindrical structure made of insulating material. The through insulator (12) includes a first through insulator (121) and a second through insulator (122). The first through insulator (121) is fixed inside the electrode block body (11), and the second through insulator (122) is fixed outside the electrode block body (11). The second through insulator (122) and the electrode block body (11) can move along the longitudinal axis of symmetry of the arc channel. The second through insulator (122) is slidably disposed inside the unified nozzle assembly (40). The air inlet pipe (13) is used to introduce plasma forming gas into the electrode unit (10) and form a vortex. The air inlet pipe (13) includes a first air inlet pipe (131) and a second air inlet pipe (132). The gas delivery direction of the first air inlet pipe (131) is tangentially arranged relative to the inner surface of the electrode block body (11). The second air inlet pipe (132) is arranged on the second through insulator (122). The gas delivery direction of the second air inlet pipe (132) is tangentially arranged relative to the guide surface of the unified nozzle assembly (40). The electrode support (14) is made of metal material and is fixedly installed inside the first through insulator (121). The electrode support (14) has a second thickened part (141) on the side near the first thickened part (111). The electrode support (14) has a groove (142) inside. The groove (142) has a first sealing element (143) and a second sealing element (145) on both sides. The end of the electrode support (14) is connected to a feeding mechanism (144). The feeding mechanism (144) is used to drive the electrode (15) to move along the longitudinal axis of symmetry of the arc channel toward the arc channel outlet (30). The first thickened portion (111), together with the front wall of the second through insulator (122), the second air inlet pipe (132), and the guide surface of the unified nozzle assembly (40), constitute a first vortex chamber. The first vortex chamber is used as the area for igniting an electric arc between the electrode block body (11) and the guide surface of the unified nozzle assembly (40). The second thickened portion (141), together with the front wall of the first through insulator (121) and the first air inlet pipe (131), constitute a second vortex chamber. The second vortex chamber is used as the area for igniting an electric arc between the electrode support (14) and the inner surface of the electrode block body (11).

2. The universal multi-gas AC arc plasma generator according to claim 1, characterized in that, The groove (142), together with the first seal (143), the second seal (145), and the side of the electrode (15), form a cooling jacket. The unified nozzle assembly (40) consists of three arc channels and a cooling jacket.

3. The universal multi-gas AC arc plasma generator according to claim 1, characterized in that, The electrode (15) is a cylindrical structure with smooth sidewalls and is made of conductive material.

4. The universal multi-gas AC arc plasma generator according to claim 1, characterized in that, The plasma generator is powered by a high-voltage three-phase AC power grid. The plasma forming medium of the plasma generator is a single gas or a mixture of any two or more gases, including air, nitrogen, argon, helium, carbon dioxide, hydrogen, gaseous and vaporous hydrocarbons, and hydrogen sulfide.

Images