A direct current water vapor plasma torch with preheating

Abstract

The application discloses a direct-current water vapor plasma torch with preheating, which comprises a cathode, a first anode and a second anode, the outer periphery of the cathode is provided with a cathode water cooling jacket, the outer periphery of the first anode is provided with a first anode water cooling jacket, the outer periphery of the second anode is provided with a second anode water cooling jacket, a first anode heating jacket is arranged between the first anode and the first anode water cooling jacket, and a second anode heating jacket is arranged between the second anode and the second anode water cooling jacket. The application has the beneficial effects that: the heating resistance wire is preheated, the preheating method is compared with the traditional preheating method of taking air or nitrogen as an arc starting working gas, nitrogen oxides are not generated, the method is more green and environmentally friendly, the working gas does not need to be switched after preheating, the operation is more convenient, in addition, the preheating method of the device is uniform and controllable, the wall surface temperature can be accurately adjusted to a target value, the preheating reaction speed is faster, and the problem of arc starting failure caused by water vapor condensation is effectively avoided.

Description

Technical Field

[0001] This application belongs to the field of plasma torch technology, specifically relating to a direct current steam plasma torch with preheating. Background Technology

[0002] With rapid economic and technological development, the amount of hazardous waste generated is constantly increasing. Currently, the comprehensive disposal rate of hazardous waste is still low, with a large gap, making it imperative to improve the utilization and disposal rate of hazardous waste. Thermal plasma hazardous waste treatment technology has significant advantages in terms of energy consumption, economy, and sustainability. Therefore, with the increasing global demand for sustainable development and increasingly stringent environmental standards, thermal plasma technology has become an important development direction for future hazardous waste treatment.

[0003] In industrial applications, the working gas of plasma torches, the core equipment for generating high-temperature jets, is mostly inexpensive air or nitrogen. This results in the generation of high concentrations of nitrogen oxides (approximately 2000-3000 mg / m³ per hour) during operation. 3 This secondary pollution poses a significant challenge to exhaust gas purification, and the generation of nitrogen oxides increases exponentially with increasing discharge power. Therefore, air / nitrogen is no longer suitable as the discharge gas for large-capacity thermal plasma waste treatment systems, severely limiting further improvements in waste treatment efficiency and greatly increasing the cost and difficulty of subsequent exhaust gas purification. To address these issues, widely available, inexpensive, and environmentally friendly water vapor can be used as the discharge gas medium for thermal plasma, completely suppressing nitrogen oxide generation at the source and eliminating the adverse effects of secondary gas pollution on subsequent treatment.

[0004] Compared to air and nitrogen plasma, water vapor arc plasma has an enthalpy nearly an order of magnitude higher, and its H and OH free radicals give it highly efficient redox properties. However, a critical problem needs to be addressed when using water vapor as a discharge gas medium for thermal plasma: water vapor is extremely prone to condensation, rapidly condensing into liquid water upon contact with a cooler object. Therefore, effectively solving the condensation problem of water vapor within the plasma torch is a core issue for its stable application as a discharge gas medium. In practical applications, the water vapor condensation problem is particularly prominent at the initial moment of introducing water vapor to start the arc. At this time, the torch wall temperature is low, and the water vapor condenses rapidly upon contact, ultimately preventing the arc from starting normally.

[0005] Current conventional preheating methods typically use air or nitrogen as the initial discharge gas medium to initiate the arc. After the torch has been running for a period of time and the wall temperature has risen, the air or nitrogen flow rate is gradually reduced while the steam supply is increased until the working medium is completely switched to steam. This method has significant drawbacks: first, using air or nitrogen as the discharge gas medium during preheating generates nitrogen oxides, causing environmental pollution; second, it requires precise control of the ratios and switching processes of multiple gases, making the operation cumbersome and complex; and third, it adds an extra air and nitrogen supply system, increasing the overall equipment cost. Summary of the Invention

[0006] The purpose of this application is to provide a preheated DC steam plasma torch to solve the problems of difficulty in preheating the torch body wall, uneven and insufficient preheating, and inability to accurately control the preheating temperature when starting the arc in existing DC steam plasma torches. This avoids the situation where steam condenses due to the above problems, ultimately causing arc failure.

[0007] This application proposes a preheated DC steam plasma torch. Heating jackets (resistance wires) are added between the first anode, the second anode, and the water-cooling structure. This preheats the walls of the first and second anodes before arc ignition, fundamentally preventing arc ignition failure caused by steam condensation. Therefore, compared with existing preheating schemes using air or nitrogen as the arc discharge gas medium, this application has several significant advantages: it does not produce nitrogen oxide pollutants, making it more environmentally friendly; it eliminates the need for switching and controlling multiple working gases, simplifying the operation process; it eliminates the need for additional auxiliary gas supply equipment, effectively reducing the overall equipment cost; and the resistance wire preheating method provides uniform and precise temperature control, maintaining the torch wall surface stably at the predetermined target temperature, with a faster preheating response.

[0008] The objective of this application is achieved through the following technical solution: A preheated DC steam plasma torch includes a cathode, a first anode, and a second anode. The cathode is provided with a cathode water-cooling jacket, the first anode is provided with a first anode water-cooling jacket, the second anode is provided with a second anode water-cooling jacket, a first anode heating jacket is provided between the first anode and the first anode water-cooling jacket, and a second anode heating jacket is provided between the second anode and the second anode water-cooling jacket.

[0009] Furthermore, the cathode water-cooling jacket is provided with a protective gas passage, which is relative to the working end of the cathode. The first anode water-cooling jacket is provided with a water vapor distribution ring inside, which is located in the gap between the first anode and the second anode.

[0010] Furthermore, the first anode heating jacket includes a first heating resistance wire, a first resistance wire base, and a first resistance wire cover. The first resistance wire base is provided on the outer periphery of the first anode, and the first resistance wire cover is provided on the outer periphery of the first resistance wire base. The first heating resistance wire is disposed in the resistance wire annular groove formed between the first resistance wire base and the first resistance wire cover. The first power supply line of the first heating resistance wire passes through the first power supply line hole of the first resistance wire cover and the first heating through hole of the first anode water cooling jacket.

[0011] Furthermore, the second anode heating jacket includes a second heating resistance wire, a second resistance wire base, and a second resistance wire cover. The second resistance wire base is provided on the outer periphery of the second anode, and a through groove is provided on the inner periphery of the second resistance wire base. The second resistance wire cover is provided on the outer periphery of the second resistance wire base. The second heating resistance wire is disposed in the resistance wire peripheral groove formed between the second resistance wire base and the second resistance wire cover. The second power supply line of the second heating resistance wire passes through the second power supply line hole of the second resistance wire cover and the second heating through hole of the second anode water cooling jacket.

[0012] Furthermore, the cathode water-cooling jacket includes a cathode inlet pipe, a cathode outlet pipe, a cathode water-cooling outer jacket, and a cathode water-cooling inner jacket. The cathode water-cooling outer jacket contains a cathode and a cathode water-cooling inner jacket. The cathode inlet pipe is connected to the inner sleeve passage of the cathode water-cooling inner jacket. The inner sleeve passage is opposite to the cooling end of the cathode. The inner sleeve passage connects to the jacket passage between the cathode water-cooling outer jacket and the cathode water-cooling inner jacket. The jacket passage is connected to the cathode outlet pipe.

[0013] Furthermore, the cathode water-cooled jacket includes a protective gas inlet pipe, an insulating protective sleeve, and a cathode water-cooled outer jacket. The outer periphery of the cathode water-cooled outer jacket is provided with an insulating protective sleeve. The protective gas inlet pipe is connected to the protective passage inside the insulating protective sleeve, and the protective passage is opposite to the working end of the cathode.

[0014] Furthermore, the first anode water-cooling jacket includes a first inlet pipe, a first outlet pipe, a first water-cooling jacket flange, a water-proof baffle, and a sealing ring. The first water-cooling jacket flange is located on the outer periphery of the first anode. An installation annular groove is formed on the outer periphery of the first anode. The first anode heating jacket is located at the bottom of the installation annular groove, and a sealing ring is located at the opening of the installation annular groove. An annular passage is formed between the first anode heating jacket and the sealing ring. The water-proof baffle cuts off the annular passage. The first inlet pipe is connected to one end of the annular passage, and the first outlet pipe is connected to the other end of the annular passage.

[0015] Furthermore, the first anode water-cooled jacket includes a steam inlet pipe and a first water-cooled jacket flange, with a steam distribution ring located inside the first water-cooled jacket flange, and the steam inlet pipe being opposite to the steam distribution ring.

[0016] Furthermore, the second anode water-cooling jacket includes a second inlet pipe, a second outlet pipe, a second water-cooling jacket flange, a lower outer cylinder of the water-cooling jacket, a sealing seat, and an upper outer cylinder of the water-cooling jacket. A second anode heating jacket is provided on the outer periphery of the second anode, and a second water-cooling jacket flange is provided on the outer periphery of the second anode heating jacket. The lower end of the second water-cooling jacket flange is connected to the lower outer cylinder of the water-cooling jacket fitted on the second anode heating jacket, and the upper end of the second water-cooling jacket flange is connected to the upper outer cylinder of the water-cooling jacket fitted on the second anode heating jacket. The second inlet pipe connects the lower cylinder sleeve passage between the second anode heating jacket and the lower outer cylinder of the water-cooling jacket, and the second outlet pipe connects the upper cylinder sleeve passage between the second anode heating jacket and the upper outer cylinder of the water-cooling jacket. The lower cylinder sleeve passage and the upper cylinder sleeve passage are connected through the electrode sleeve passage between the second anode and the second anode heating jacket.

[0017] Further, the operating method is as follows: the water cooling systems in the cathode water cooling jacket, the first anode water cooling jacket, and the second anode water cooling jacket are shut down. The first anode heating jacket and the second anode heating jacket are started to heat the first anode and the second anode, respectively. When the monitored temperature reaches the preset arc ignition preheating temperature threshold, the protective gas passage is opened to protect the working end of the cathode. Then, water vapor is supplied to the electrical chamber through the water vapor distribution ring. Then, the first anode heating jacket and the second anode heating jacket are shut down and arc ignition is initiated. After successful arc ignition, the cathode water cooling jacket, the first anode water cooling jacket, and the second anode water cooling jacket are started to continuously cool and dissipate heat from the cathode, the first anode, and the second anode, respectively.

[0018] The beneficial effects of this application are: (1) The DC steam plasma torch of this application has a built-in heating resistance wire for preheating. Compared with the traditional preheating method that uses air or nitrogen as the arc-starting working gas, its preheating method has significant advantages: it does not produce nitrogen oxides, making it more environmentally friendly; and it does not require switching the working gas after preheating, making it more convenient to operate. In addition, the preheating method of this device is uniform and controllable, and can accurately adjust the wall temperature to the target value. Moreover, the preheating reaction speed is faster, effectively avoiding the problem of arc-starting failure caused by steam condensation.

[0019] (2) The heating resistance wire sleeve structure of this application is reasonably designed. The first and second heating resistance wires are both made of iron-chromium-aluminum electric heating alloy. Compared with the traditional nickel-chromium electric heating alloy, the operating temperature is higher, the life is longer, the resistivity is higher, and the heating is faster. The resistance wire sleeve is made of ceramic base and cover, which has good insulation and uniform heat transfer, and can avoid the influence of electrode voltage. At the same time, the welded sealing design is adopted, and the waterproof structure can effectively prevent coolant leakage from damaging the resistance wire and ensure preheating stability. In addition, the second anode heating sleeve also functions as a water-cooled jacket water-proof inner cylinder, realizing the integration of preheating and water isolation, without interfering with the flow of coolant, and taking into account both preheating effect and cooling requirements.

[0020] (3) The first and second anode water cooling jackets of this application are reliably sealed and made of compatible materials. All parts are connected by welding to ensure sealing. The coolant flow path is reasonably designed so that the coolant can stay in the concentrated heating part of the electrode for a longer time, resulting in better cooling effect and effectively preventing the electrode from being damaged due to overheating. At the same time, with the automatic interlocking operation program, the preheating, arc ignition, operation and shutdown processes can be fully automated, eliminating the need for manual step-by-step operation, reducing human error, and real-time monitoring of parameters such as temperature and flow rate, further ensuring the success rate of arc ignition and the safety of equipment operation. The standardized shutdown process can also avoid equipment damage and extend the service life of the equipment.

[0021] (4) The gas distribution ring used in the DC steam plasma torch of this application is made of ceramic material and has a square tangential groove on the upper end face. Compared with the conventional swirling gas ring structure, it saves a lot of installation space and can make full use of the narrow gap between the first anode and the second anode to directly transport water vapor to the two electrodes, shortening the transmission path of water vapor and further reducing the probability of condensation of water vapor due to the low wall temperature during transmission. At the same time, the tangential air intake can form a plasma jet with a vortex structure, which improves the stability of the arc column.

[0022] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding the solution of this application, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected by this application, and will not be exhaustively listed here. Attached Figure Description

[0023] Figure 1 This is a structural cross-sectional view of this application.

[0024] Figure 2 This is a structural appearance drawing of this application.

[0025] Figure 3 This is a structural exploded view of the first anode heating jacket of this application.

[0026] Figure 4 This is an exploded view of the structure of the second anode heating jacket in this application.

[0027] In the diagram: 1-Cathode, 2-First Anode, 3-Second Anode, 4-First Anode Heating Jacket, 5-Second Anode Heating Jacket, 6-Cathode Water Cooling Jacket, 7-First Anode Water Cooling Jacket, 8-Second Anode Water Cooling Jacket, 9-Water Vapor Distribution Ring; 4-1-First Heating Resistance Wire, 4-2-First Resistance Wire Base, 4-3-First Resistance Wire Cover, 4-4-First Power Supply Hole; 5-1-Second Heating Resistance Wire, 5-2-Second Resistance Wire Base, 5-3-Second Resistance Wire Cover, 5-4-Second Power Supply Hole, 5-5-Through Groove; 6-1-Cathode Water Inlet Pipe, 6-2- 6-3-Protective gas inlet pipe, 6-4-Insulating protective sleeve, 6-5-Cathode water-cooled outer sleeve, 6-6-Cathode water-cooled inner sleeve; 7-1-First water inlet pipe, 7-2-First water outlet pipe, 7-3-First heating perforation, 7-4-Water vapor inlet pipe, 7-5-First water-cooled sleeve flange, 7-6-Waterproof baffle, 7-7-Sealing ring; 8-1-Second water inlet pipe, 8-2-Second water outlet pipe, 8-3-Second heating perforation, 8-4-Second water-cooled sleeve flange, 8-5-Lower outer cylinder of water-cooled sleeve, 8-6-Sealing seat, 8-7-Upper outer cylinder of water-cooled sleeve. Detailed Implementation

[0028] The following non-limiting embodiments are used to illustrate this application.

[0029] Example 1 refer to Figures 1-4 As shown, a preheated DC steam plasma torch includes a cathode 1, a first anode 2, a second anode 3, a first anode heating jacket 4, a second anode heating jacket 5, a cathode water-cooling jacket 6, a first anode water-cooling jacket 7, a second anode water-cooling jacket 8, and a steam distribution ring 9.

[0030] Cathode 1, first anode 2, and second anode 3 are arranged sequentially along the axial direction. A cathode water-cooling jacket 6 is provided around the outer periphery of cathode 1 for cooling. A first anode water-cooling jacket 7 is provided around the outer periphery of first anode 2 for cooling. A second anode water-cooling jacket 8 is provided around the outer periphery of second anode 3 for cooling.

[0031] A first anode heating jacket 4 is provided between the first anode 2 and the first anode water-cooling jacket 7 for preheating the first anode 2 and preventing water vapor condensation caused by low temperature. A second anode heating jacket 5 is provided between the second anode 3 and the second anode water-cooling jacket 8 for preheating the second anode 3 and preventing water vapor condensation caused by low temperature.

[0032] The cathode water-cooled jacket 6 is provided with a protective gas passage, which is relative to the working end of the cathode 1 (the end closest to the anode) and is used to supply protective gas to the working end of the cathode 1 to prevent water vapor from corroding the cathode 1. The first anode water-cooled jacket 7 is provided with a water vapor distribution ring 9 inside, which is located in the gap between the first anode 2 and the second anode 3. Water vapor is evenly supplied to the gap between the two anodes through the water vapor distribution ring 9.

[0033] The first anode heating jacket 4 is a closed and waterproof cylindrical structure, located between the first anode 2 and the first anode water-cooling jacket 7. The first anode heating jacket 4 includes a first heating resistance wire 4-1, a first resistance wire base 4-2, and a first resistance wire cover 4-3. The first heating resistance wire 4-1, the first resistance wire base 4-2, and the first resistance wire cover 4-3 are all annular to achieve an outer jacket arrangement on the first anode 2.

[0034] A first resistance wire base 4-2 is fixedly mounted on the outer periphery of the first anode 2, and a first resistance wire cover 4-3 is fixedly mounted on the outer periphery of the first resistance wire base 4-2. A first heating resistance wire 4-1 is disposed within a resistance wire annular groove formed between the first resistance wire base 4-2 and the first resistance wire cover 4-3, i.e., the first heating resistance wire 4-1 is enclosed between the first resistance wire base 4-2 and the first resistance wire cover 4-3, achieving waterproofing. During preheating, the first heating resistance wire 4-1 is energized and heats up, transferring heat to the first anode 2 through the base and cover, thus achieving anode preheating.

[0035] The first heating resistance wire 4-1 is made of iron-chromium-aluminum heating alloy and is a conventional spring-shaped cylindrical heating wire. Both the first resistance wire base 4-2 and the first resistance wire cover 4-3 are annular structures made of ceramic material, with grooves on their inner sides. The first heating resistance wire 4-1 is embedded in these grooves, and the two are welded together to seal the first heating resistance wire 4-1 internally. A through hole is formed on the first resistance wire cover 4-3, creating the first power supply wire hole 4-4.

[0036] The first power supply line of the first heating resistance wire 4-1 passes through the first power supply line hole 4-4 of the first resistance wire cover 4-3 and the first heating through hole 7-3 of the first anode water-cooling jacket 7, realizing the internal and external arrangement of the first power supply line and connecting it to an external power source. A water-proof baffle 7-6 is welded between the first resistance wire cover 4-3 and the sealing ring 7-7 inside the first anode water-cooling jacket 7. The first power supply line passes through a radial pre-drilled hole on the water-proof baffle 7-6, isolating the annular passage containing liquid through the water-proof baffle 7-6, and then exits the device through the sealing ring 7-7 and the first heating through hole 7-3. In other words, after the power supply line of the resistance wire passes through the first power supply line hole 4-4, it enters the through hole on the water-proof baffle 7-6, and finally exits the device through the first heating through hole 7-3 on the first water-cooling jacket flange 7-5.

[0037] The first heating resistance wire 4-1 is made of iron-chromium-aluminum heating alloy, which, compared to nickel-chromium heating alloy, offers advantages such as higher operating temperature, longer service life, higher resistivity, and faster heating speed. Both the first resistance wire base 4-2 and the first resistance wire cover 4-3 are made of ceramic, which has excellent insulation properties, effectively mitigating the voltage influence of the first anode 2 and ensuring more uniform heating and heat transfer. The two are sealed together by welding, ensuring the stability of the overall structure and effectively preventing coolant leakage, thus avoiding damage to the internal heating resistance wire.

[0038] The second anode heating jacket 5 is a closed, waterproof cylindrical structure located between the second anode 3 and the second anode water-cooling jacket 8. The second anode heating jacket 5 includes a second heating resistance wire 5-1, a second resistance wire base 5-2, and a second resistance wire cover 5-3. The second heating resistance wire 5-1, the second resistance wire base 5-2, and the second resistance wire cover 5-3 are all annular to achieve an outer jacket arrangement on the second anode 3.

[0039] A second resistance wire base 5-2 is fixedly mounted on the outer periphery of the second anode 3. A through groove 5-5 is provided on the inner periphery of the second resistance wire base 5-2, forming an axial gap between the second anode 3 and the second resistance wire base 5-2 to allow for continuous flow of coolant. A second resistance wire cover 5-3 is fixedly mounted on the outer periphery of the second resistance wire base 5-2. A second heating resistance wire 5-1 is disposed in the resistance wire circumferential groove formed between the second resistance wire base 5-2 and the second resistance wire cover 5-3, effectively sealing the second heating resistance wire 5-1 between the second resistance wire base 5-2 and the second resistance wire cover 5-3 for waterproofing. During preheating, the second heating resistance wire 5-1 is energized and heats up, transferring heat to the second anode 3 through the base and cover, thus preheating the anode.

[0040] The second heating resistance wire 5-1 is made of iron-chromium-aluminum electrothermal alloy and is a conventional spring-shaped cylindrical heating wire, wound in an arc shape within the groove on the outer surface of the second resistance wire base 5-2. Both the second resistance wire base 5-2 and the second resistance wire cover 5-3 are made of ceramic. The second resistance wire base 5-2 has a cylindrical structure with a spline-shaped groove (i.e., a through groove 5-5) on its inner surface and a groove on its outer surface for winding the resistance wire. During assembly, the inner surface of the second resistance wire base 5-2 is tightly fitted to the outer surface of the second anode 3, allowing coolant to flow along the spline-shaped groove on its inner side. The second resistance wire cover 5-3 has a cylindrical structure with a stepped end, which is welded to the second water-cooling jacket flange 8-4.

[0041] The second power supply line of the second heating resistance wire 5-1 passes through the second power supply line hole 5-4 of the second resistance wire cover 5-3 and the second heating through hole 8-3 of the second anode water-cooling jacket 8. The second water-cooling jacket flange 8-4 on the second anode water-cooling jacket 8 is directly welded to the second power supply line hole 5-4 of the second resistance wire cover 5-3, providing water isolation. The second anode heating jacket 5 also functions as the water-isolated inner cylinder of the second anode water-cooling jacket 8 and preheats the second anode 3. The second power supply line is directly led out through the second power supply line hole 5-4 of the second resistance wire cover 5-3 and the second heating through hole 8-3 of the second anode water-cooling jacket 8. The second resistance wire cover 5-3 has a through hole forming the second power supply line hole 5-4. After passing through the second power supply line hole 5-4, the power supply line of the resistance wire connects to the second heating through hole 8-3 on the second water-cooling jacket flange 8-4 and is finally led out of the device.

[0042] The second heating resistance wire 5-1 is made of iron-chromium-aluminum heating alloy, which, compared to nickel-chromium heating alloy, offers a higher operating temperature, longer service life, higher resistivity, and faster heating speed. Both the second resistance wire base 5-2 and the second resistance wire cover 5-3 are made of ceramic, whose excellent insulation properties effectively mitigate the voltage influence of the second anode 3, while also ensuring more uniform heating and heat transfer. The welded, sealed connection between the two components ensures the stability of the overall structure and effectively prevents coolant leakage that could damage the internal resistance wire.

[0043] The heating sleeve of the resistance wire is designed as a closed, waterproof cylindrical structure, which effectively prevents the anode coolant from wetting the resistance wire and thus preventing damage due to water contact. Furthermore, the resistance wire sleeve and the water-cooling sleeve are welded together, further enhancing the sealing effect and structurally eliminating the problem of coolant seepage causing damage to the heating resistance wire. In addition, the resistance wire power supply line is led out through a dedicated power supply port and connected to an external power source. The heating temperature of the internal resistance wire can be directly adjusted by regulating the external power supply parameters, thereby achieving precise control of the preheating temperature of the plasma torch wall. This control method is also simpler to operate.

[0044] The cathode water-cooling jacket 6 includes a cathode water inlet pipe 6-1, a cathode water outlet pipe 6-2, a protective gas inlet pipe 6-3, an insulating protective sleeve 6-4, a cathode water-cooling outer sleeve 6-5, and a cathode water-cooling inner sleeve 6-6. Except for the insulating protective sleeve 6-4, which is made of polytetrafluoroethylene, all other components are made of stainless steel.

[0045] The cathode water-cooled jacket 6-5 houses a cathode 1 and a cathode water-cooled inner jacket 6-6. The cathode inlet pipe 6-1 passes through the cathode water-cooled jacket 6-5 and connects to the inner sleeve passage of the cathode water-cooled inner jacket 6-6. This inner sleeve passage is opposite to the cooling end of the cathode 1 (the end facing away from the anode). The inner sleeve passage connects to the jacket passage between the cathode water-cooled jacket 6-5 and the cathode water-cooled inner jacket 6-6, and the jacket passage connects to the cathode outlet pipe 6-2. Coolant enters the inner sleeve passage of the cathode water-cooled inner jacket 6-6 from the cathode inlet pipe 6-1, then passes near the cooling end of the cathode 1, exits into the jacket passage between the cathode water-cooled jacket 6-5 and the cathode water-cooled inner jacket 6-6, and finally flows out from the cathode outlet pipe 6-2. This process removes the heat generated by the cathode 1 during operation, preventing damage due to overheating.

[0046] An insulating protective sleeve 6-4 is provided around the outer periphery of the cathode water-cooled jacket 6-5. The protective gas inlet pipe 6-3 is connected to the protective passage inside the insulating protective sleeve 6-4, and the protective passage is opposite to the working end of the cathode 1 (the end closest to the anode). The protective gas enters from the protective gas inlet pipe 6-3, passes through the tangential small hole on the insulating protective sleeve 6-4, and forms a circumferential airflow shielding layer near the working end of the cathode 1 to reduce the corrosion of the cathode 1 by water vapor plasma. The cathode protective gas can be argon, carbon dioxide, or other gases.

[0047] The cathode water-cooled jacket 6 structure can promptly remove the heat generated by the cathode 1, preventing the cathode 1 from being burned out due to high temperature. It can also form an effective circumferential protective gas shield layer on the cathode surface, reducing the corrosion of the cathode 1 by water vapor plasma.

[0048] The first anode water-cooled jacket 7 includes a first water inlet pipe 7-1, a first water outlet pipe 7-2, a first heating perforation 7-3, a steam inlet pipe 7-4, a first water-cooled jacket flange 7-5, a water-proof baffle 7-6, and a sealing ring 7-7. The sealing ring 7-7 is made of brass, the water-proof baffle 7-6 is made of copper, and the remaining components are made of stainless steel.

[0049] An installation annular groove is provided on the outer periphery of the first anode 2. A first anode heating sleeve 4 is provided at the bottom of the installation annular groove. A sealing ring 7-7 is provided at the opening of the installation annular groove. The sealing ring 7-7 is welded and sealed to the first anode 2. An annular passage is formed between the first anode heating sleeve 4 and the sealing ring 7-7. Coolant can flow in this space to cool the first anode 2.

[0050] A water-blocking baffle 7-6 interrupts the annular passage. The first inlet pipe 7-1 is connected to one end of the annular passage, and the first outlet pipe 7-2 is connected to the other end. An opening is formed in the sealing ring 7-7, through which the water-blocking baffle 7-6 is inserted. The water-blocking baffle 7-6, the sealing ring 7-7, and the first resistance wire cover 4-3 of the first anode heating jacket 4 are all welded together. The water-blocking baffle 7-6 interrupts the annular passage and divides it into a semi-annular coolant space. Coolant enters from one side of this semi-annular coolant space, flows through the entire coolant space, and exits from the other side, completing the cooling operation of the first anode 2. The first water-cooling jacket flange 7-5 is located on the outer periphery of the first anode 2. The first inlet pipe 7-1, the first outlet pipe 7-2, the first heating perforation 7-3, and the steam inlet pipe 7-4 are all distributed on the first water-cooling jacket flange 7-5.

[0051] Both the first anode heating sleeve 4 and the annular passage are located within the mounting annular groove of the first anode 2. This allows the coolant to remain around the concentrated heat-generating area of ​​the first anode 2 for a longer period, more efficiently removing the heat generated during operation and effectively preventing damage to the first anode 2 due to overheating. Simultaneously, the first anode heating sleeve 4 is in close contact with the outer wall of the first anode 2, resulting in better heating. Furthermore, heat can be conducted to the surrounding area through the first anode 2, achieving overall heating of the space surrounding the first anode 2. This effectively prevents condensation due to excessively low wall temperatures when water vapor is introduced.

[0052] The steam distribution ring 9 is made of ceramic, with a square tangential groove on its upper surface, which fits tightly against the first water-cooled jacket flange 7-5. The steam distribution ring 9 is located inside the first water-cooled jacket flange 7-5, with the steam inlet pipe 7-4 opposite it. Steam enters the first water-cooled jacket flange 7-5 through the steam inlet pipe 7-4, then tangentially enters the gap between the first anode 2 and the second anode 3 through the square tangential groove on the upper surface of the steam distribution ring 9. It is then ionized by the electric arc, ultimately forming a vortex-structured steam plasma jet, which exits from the outlet of the second anode 3. During the preheating stage, heat is transferred from the first anode heating jacket 4 and the second anode heating jacket 5 to the first anode 2 and the second anode 3, and then gradually conducted to the steam distribution ring 9, achieving uniform heating of the steam distribution ring 9.

[0053] The steam distribution ring 9 is made of ceramic, offering excellent thermal insulation and easier temperature maintenance. Even after the heating device is stopped after arc ignition, its temperature will not drop rapidly, effectively preventing steam condensation due to excessively low ring wall temperature. Simultaneously, the insulating properties of the ceramic material prevent potential conduction between the second anode 3 and the first anode 2 caused by excessive pressing during manufacturing. Furthermore, the square tangential groove on the upper surface of the steam distribution ring 9, in conjunction with the first water-cooling jacket flange 7-5, forms a tangential air intake path, forcing steam to enter the discharge chamber tangentially. This creates a vortex structure in the ionized steam plasma, effectively improving the stability of the arc column. This tangential air intake structure significantly saves installation space compared to conventional swirling ring structures, fully utilizing the narrow gap between the first anode 2 and the second anode 3 to directly transport steam between the two electrodes, shortening the steam transmission path and further reducing the probability of steam condensation during transmission.

[0054] The second anode water-cooled jacket 8 includes a second inlet pipe 8-1, a second outlet pipe 8-2, a second heating perforation 8-3, a second water-cooled jacket flange 8-4, a lower outer cylinder of the water-cooled jacket 8-5, a sealing seat 8-6, and an upper outer cylinder of the water-cooled jacket 8-7. All components of the second anode water-cooled jacket 8 are made of stainless steel, and all components are connected by welding to ensure the overall sealing performance.

[0055] A second anode heating sleeve 5 is provided on the outer periphery of the second anode 3. A second water-cooling sleeve flange 8-4 is fixedly provided on the outer periphery of the second anode heating sleeve 5. The second water-cooling sleeve flange 8-4 is fixed in the middle of the second anode heating sleeve 5. The lower end of the second water-cooling sleeve flange 8-4 is fixedly connected to the lower outer cylinder 8-5 of the water-cooling sleeve fitted on the second anode heating sleeve 5, and the upper end of the second water-cooling sleeve flange 8-4 is fixedly connected to the upper outer cylinder 8-7 of the water-cooling sleeve fitted on the second anode heating sleeve 5. The second water inlet pipe 8-1, the second water outlet pipe 8-2, and the second heating perforation 8-3 are evenly distributed on the second water-cooling sleeve flange 8-4.

[0056] The second inlet pipe 8-1 connects the lower sleeve passage between the second anode heating jacket 5 and the lower outer cylinder 8-5 of the water-cooling jacket. The second outlet pipe 8-2 connects the upper sleeve passage between the second anode heating jacket 5 and the upper outer cylinder 8-7 of the water-cooling jacket. The lower sleeve passage and the upper sleeve passage are connected by the pole sleeve passage between the second anode 3 and the second anode heating jacket 5 (i.e., the space formed by the through groove 5-5). The coolant enters the lower sleeve passage from the second inlet pipe 8-1, flows from the middle to the bottom to absorb heat, and then flows to the bottom (the outlet side of the second anode 3), enters the pole sleeve passage between the second anode 3 and the second anode heating jacket 5, and then flows from bottom to top to absorb heat from the second anode 3. Then it enters the upper sleeve passage from the top, flows from the top to the middle, and finally exits from the second outlet pipe 8-2. The cooling path overlaps inside and outside to achieve two cooling cycles.

[0057] The second anode heating jacket 5 also functions as the water-isolating jacket of the second anode water-cooling jacket 8. The flow path of the coolant is as follows: it enters the lower outer cylinder 8-5 of the water-cooling jacket from the second inlet pipe 8-1, then flows through the spline-shaped groove of the second resistance wire base 5-2 to the upper outer cylinder 8-7 of the water-cooling jacket, and finally flows out of the device from the second outlet pipe 8-2. This second anode heating jacket 5 can effectively preheat the second anode 3 by closely adhering to its outer surface, without affecting the cooling effect of the coolant on the second anode 3 during plasma torch operation.

[0058] The design of the second anode water-cooling jacket 8 is more concise, with the power supply line of the resistance wire in the second anode heating jacket 5 directly led out of the device, eliminating the need for complex wiring design. The coolant can gradually flow from the outlet side of the second anode 3 to the steam inlet side. During the operation of the plasma torch, the flowing coolant will be heated by the wall of the second anode 3. When the water flows to the periphery of the second anode 3 at the steam inlet side, it has reached a certain temperature, which can effectively prevent the wall of the second anode 3 in this area from being too cold, causing condensation after contact with steam.

[0059] The operation method of the plasma torch includes the following steps: S1. After receiving the start command, the central control system automatically executes the following interlocking steps: closing the coolant inlet valve (i.e., closing the water cooling system in the cathode water-cooling jacket 6, the first anode water-cooling jacket 7, and the second anode water-cooling jacket 8), the power switches for cathode 1, first anode 2, and second anode 3, the protective gas inlet valve, and the steam inlet valve. Opening the coolant outlet valve to drain the coolant from the device, and keeping the outlet valve open after draining. Starting the first anode heating jacket 4 and the second anode heating jacket 5 to heat the first anode 2 and the second anode 3 respectively, automatically and slowly increasing the temperature in a stepped manner according to the preset program.

[0060] S2. The infrared temperature sensor is linked with the control system to automatically monitor the inner surface temperature of the first anode 2 and the second anode 3 in real time, and the temperature data is continuously transmitted back to the control system.

[0061] S3. When the control system determines that the monitored temperature has reached the preset arc ignition preheating temperature threshold, it automatically interlocks and opens the protective gas inlet valve. The protective gas is automatically input into the vicinity of cathode 1 through the protective gas inlet pipe 6-3, and the flow rate is automatically adjusted to the preset value to protect the working end of cathode 1.

[0062] S4. After the protective gas flow rate reaches the preset stable value, the control system automatically triggers the steam supply process. The steam inlet valve is opened, and the steam generator and steam heater are started simultaneously. The steam heater automatically heats the steam to the preset superheated state, and the flow regulating valve automatically adjusts the steam flow rate to the preset arc ignition flow rate. The steam is automatically delivered to the discharge chamber through the steam inlet pipe 7-4, and then supplied to the discharge chamber through the steam distribution ring 9.

[0063] S5. Once the steam flow rate and temperature reach the preset arc-starting parameters, the control system automatically shuts off the power to the first anode heating jacket 4 and the second anode heating jacket 5, stopping preheating.

[0064] S6. After the control system comprehensively determines that the preheating temperature, protective gas parameters, and steam parameters all meet the arc ignition conditions, it automatically interlocks and powers on the plasma torch power supply, automatically applies the preset open-circuit voltage to the anode and cathode, automatically adjusts the power supply output parameters and sets the operating current according to the process requirements, and then automatically starts the high-frequency pulse trigger module to complete the arc ignition.

[0065] S7. After receiving the arc ignition success feedback signal, the control system automatically opens the coolant inlet valve. The inlet and outlet valves are automatically linked and adjusted to maintain a dynamic balance of inlet and outlet water volume to achieve closed-loop water circulation. Simultaneously, the water cooling equipment is automatically started to continuously cool and dissipate heat from the anode and cathode. That is, the cathode water cooling jacket 6, the first anode water cooling jacket 7, and the second anode water cooling jacket 8 are started to continuously cool and dissipate heat from the cathode 1, the first anode 2, and the second anode 3, respectively.

[0066] S8. During equipment operation, the coolant inlet and outlet flow and temperature sensors are linked with the control system to automatically monitor parameters in real time. If a parameter is detected to exceed a preset normal threshold, the control system will immediately trigger an abnormality warning and initiate the relevant equipment self-check procedure.

[0067] S9. When the discharge power needs to be adjusted during operation, the control system automatically and synchronously adjusts the steam input flow rate, temperature and plasma power output parameters according to the process instructions to achieve closed-loop power control.

[0068] S10. After receiving the shutdown command, the control system automatically shuts off the plasma torch power supply and cuts off the arc power supply.

[0069] S11. After the plasma torch power supply shutdown signal is transmitted back to the control system, the power supply to the steam generator and steam heater is automatically shut off, and the steam inlet valve is closed simultaneously to stop the steam input.

[0070] S12. After the steam delivery stop signal is transmitted back to the control system, the protective gas inlet valve is automatically closed to stop the input of protective gas.

[0071] S13. After the protective gas supply stops, the temperature sensor continues to automatically monitor the overall temperature of the device. When the control system determines that the temperature has dropped to the normal environmental threshold, it automatically interlocks and closes the coolant inlet valve and outlet valve, and simultaneously shuts down the water cooling equipment.

[0072] S14. After all equipment and valves have completed the closing action, the control system automatically sends a shutdown completion signal, and the entire automatic interlocking operation program ends.

[0073] The system boasts a high degree of automation and interlocking control. The entire process—preheating, arc ignition preparation, arc ignition, operation, and shutdown—can be automatically triggered and executed, eliminating the need for frequent manual intervention. This significantly reduces operational difficulty and the probability of human error, making overall operation simpler and more efficient. Preheating is convenient and its status is intuitively determined. Preheating of key components is achieved simply by controlling the on / off power supply to the heating resistance wire. Combined with real-time automatic monitoring using infrared temperature measurement, it accurately and intuitively determines whether the preheating temperature meets the standard, providing a reliable temperature basis for successful arc ignition of the plasma torch and simplifying the preheating effect verification process. The shutdown process is automated and executed according to standardized procedures, automatically completing the process in the sequence of "power off—water and steam off—protective gas off—cooling off while waiting for cooling." This avoids equipment damage caused by improper water or gas interruptions under high-temperature conditions, effectively ensuring equipment operational safety and extending equipment lifespan.

[0074] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.

[0075] The above description is merely a preferred embodiment of this application and is 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 preheated DC steam plasma torch, comprising a cathode (1), a first anode (2), and a second anode (3), wherein a cathode water-cooling jacket (6) is provided on the outer periphery of the cathode (1), a first anode water-cooling jacket (7) is provided on the outer periphery of the first anode (2), and a second anode water-cooling jacket (8) is provided on the outer periphery of the second anode (3), characterized in that: A first anode heating sleeve (4) is provided between the first anode (2) and the first anode water cooling sleeve (7), and a second anode heating sleeve (5) is provided between the second anode (3) and the second anode water cooling sleeve (8).

2. The DC steam plasma torch with preheating according to claim 1, characterized in that: The cathode water cooling jacket (6) is provided with a protective gas passage, which is relative to the working end of the cathode (1). The first anode water cooling jacket (7) is provided with a water vapor distribution ring (9), which is located in the gap between the first anode (2) and the second anode (3).

3. The DC steam plasma torch with preheating according to claim 1 or 2, characterized in that: The first anode heating jacket (4) includes a first heating resistance wire (4-1), a first resistance wire base (4-2), and a first resistance wire cover (4-3). The first resistance wire base (4-2) is provided on the outer periphery of the first anode (2), and the first resistance wire cover (4-3) is provided on the outer periphery of the first resistance wire base (4-2). The first heating resistance wire (4-1) is located in the resistance wire annular groove formed between the first resistance wire base (4-2) and the first resistance wire cover (4-3). The first power supply line of the first heating resistance wire (4-1) passes through the first power supply line hole (4-4) of the first resistance wire cover (4-3) and the first heating through hole (7-3) of the first anode water cooling jacket (7).

4. The DC steam plasma torch with preheating according to claim 1 or 2, characterized in that: The second anode heating jacket (5) includes a second heating resistance wire (5-1), a second resistance wire base (5-2), and a second resistance wire cover (5-3). The second anode (3) is provided with a second resistance wire base (5-2) on its outer periphery. The second resistance wire base (5-2) is provided with a through groove (5-5) on its inner periphery. The second resistance wire base (5-2) is provided with a second resistance wire cover (5-3) on its outer periphery. The second heating resistance wire (5-1) is provided with a resistance wire circumferential groove formed between the second resistance wire base (5-2) and the second resistance wire cover (5-3). The second power supply wire of the second heating resistance wire (5-1) passes through the second power supply wire hole (5-4) of the second resistance wire cover (5-3) and the second heating through hole (8-3) of the second anode water cooling jacket (8).

5. The DC steam plasma torch with preheating according to claim 1, characterized in that: The cathode water-cooled jacket (6) includes a cathode inlet pipe (6-1), a cathode outlet pipe (6-2), a cathode water-cooled outer jacket (6-5), and a cathode water-cooled inner jacket (6-6). The cathode water-cooled outer jacket (6-5) is equipped with a cathode (1) and a cathode water-cooled inner jacket (6-6). The cathode inlet pipe (6-1) is connected to the inner sleeve passage of the cathode water-cooled inner jacket (6-6). The inner sleeve passage is opposite to the cooling end of the cathode (1). The inner sleeve passage is connected to the jacket passage between the cathode water-cooled outer jacket (6-5) and the cathode water-cooled inner jacket (6-6). The jacket passage is connected to the cathode outlet pipe (6-2).

6. The DC steam plasma torch with preheating according to claim 2, characterized in that: The cathode water-cooled jacket (6) includes a protective gas inlet pipe (6-3), an insulating protective sleeve (6-4), and a cathode water-cooled outer jacket (6-5). The outer periphery of the cathode water-cooled outer jacket (6-5) is provided with an insulating protective sleeve (6-4). The protective gas inlet pipe (6-3) is connected to the protective passage inside the insulating protective sleeve (6-4), and the protective passage is opposite to the working end of the cathode (1).

7. The DC steam plasma torch with preheating according to claim 1, characterized in that: The first anode water-cooled jacket (7) includes a first inlet pipe (7-1), a first outlet pipe (7-2), a first water-cooled jacket flange (7-5), a water-proof baffle (7-6), and a sealing ring (7-7). The first water-cooled jacket flange (7-5) is located on the outer periphery of the first anode (2). An installation ring groove is provided on the outer periphery of the first anode (2). A first anode heating jacket (4) is provided at the bottom of the installation ring groove. A sealing ring (7-7) is provided at the opening of the installation ring groove. An annular passage is formed between the first anode heating jacket (4) and the sealing ring (7-7). The water-proof baffle (7-6) cuts off the annular passage. The first inlet pipe (7-1) is connected to one end of the annular passage, and the first outlet pipe (7-2) is connected to the other end of the annular passage.

8. The DC steam plasma torch with preheating according to claim 2, characterized in that: The first anode water cooling jacket (7) includes a steam inlet pipe (7-4) and a first water cooling jacket flange (7-5). A steam distribution ring (9) is located inside the first water cooling jacket flange (7-5), and the steam inlet pipe (7-4) is opposite to the steam distribution ring (9).

9. The DC steam plasma torch with preheating according to claim 1, characterized in that: The second anode water-cooling jacket (8) includes a second inlet pipe (8-1), a second outlet pipe (8-2), a second water-cooling jacket flange (8-4), a lower outer cylinder of the water-cooling jacket (8-5), a sealing seat (8-6), and an upper outer cylinder of the water-cooling jacket (8-7). A second anode heating jacket (5) is provided on the outer periphery of the second anode (3), and a second water-cooling jacket flange (8-4) is provided on the outer periphery of the second anode heating jacket (5). The lower end of the second water-cooling jacket flange (8-4) is connected to the lower outer cylinder (8-5) of the water-cooling jacket fitted on the second anode heating jacket (5). The upper end of the second water-cooled jacket flange (8-4) is connected to the upper outer cylinder (8-7) of the water-cooled jacket fitted on the second anode heating jacket (5). The second water inlet pipe (8-1) connects the lower sleeve passage between the second anode heating jacket (5) and the lower outer cylinder (8-5) of the water-cooled jacket. The second water outlet pipe (8-2) connects the upper sleeve passage between the second anode heating jacket (5) and the upper outer cylinder (8-7) of the water-cooled jacket. The lower sleeve passage and the upper sleeve passage are connected through the pole sleeve passage between the second anode (3) and the second anode heating jacket (5).

10. The DC steam plasma torch with preheating according to claim 1, characterized in that, The method also includes the following operation: the cathode water cooling jacket (6), the first anode water cooling jacket (7) and the second anode water cooling jacket (8) are closed, the first anode heating jacket (4) and the second anode heating jacket (5) are started to heat the first anode (2) and the second anode (3) respectively. When the monitored temperature reaches the preset arc ignition preheating temperature threshold, the protective gas passage is opened to protect the working end of the cathode (1). Then, water vapor is supplied to the electrical chamber through the water vapor distribution ring (9). Then, the first anode heating jacket (4) and the second anode heating jacket (5) are closed and the arc is started. After the arc is successfully started, the cathode water cooling jacket (6), the first anode water cooling jacket (7) and the second anode water cooling jacket (8) are started to continuously cool and dissipate heat from the cathode (1), the first anode (2) and the second anode (3) respectively.

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