Non-transferred direct current arc plasma torch with wall stabilized arc and three-stage cooling

Abstract

The utility model discloses a kind of non-transfer type direct current electric arc plasma torch with wall steady arc and with three-stage cooling, including plasma torch body work component and cooling component, plasma torch body work component includes cathode, anode, the plasma gas passage for passing into working gas, and the cylindrical anode wall steady being arranged below anode, plasma gas passage is located at the outer periphery of cathode, anode is located at the outer periphery of plasma gas passage, the lower end of plasma gas passage is communicated with the central hole of anode wall steady;Cooling component includes the multiple-stage body cooling water channel being independently arranged along the height direction of plasma torch, and the anode wall steady cooling water channel being arranged at the outer periphery of anode wall steady, body cooling water channel is located between the outer periphery of anode and plasma torch shell.This utility model can increase the service life of plasma torch, improve the arc length and power of plasma arc, and improve the safety of use simultaneously.

Description

Technical Field

[0001] This utility model relates to a DC arc plasma torch, and more particularly to a non-transfer DC arc plasma torch that employs wall-stabilized arc and has three-stage cooling, belonging to the field of plasma torch technology. Background Technology

[0002] Plasma torches have been widely used in industrial fields such as cutting, melting metal, heating, gasification, welding and spraying, and aerospace.

[0003] A plasma torch applies a voltage between the cathode and anode. Under the influence of the electric field, electrons gain sufficient kinetic energy to ionize the gas. The accelerated electrons collide with the neutral gas, ionizing its atoms or molecules, thus forming a continuous plasma. With a stable power supply, the plasma heats the neutral gas molecules under the influence of the electric field, turning the heated gas into a high-temperature gas, which is then ejected from the nozzle of the plasma torch to form a plasma jet.

[0004] Arc plasma torches can be classified into two types based on power source: AC arc and DC arc. AC arc torches are prone to electrode corrosion and have a short lifespan, while DC arc plasma torches offer advantages such as simple structure, safety, reliability, and high thermal efficiency. The average temperature of the heat stream generated by this type of torch can reach up to 6000℃, with a thermal efficiency coefficient of 60-90%, depending on the power output and the type of plasma gas used. The cathode lifespan of the plasma torch varies from 200 to 3000 hours, and the cathode is easy to replace; therefore, DC arc plasma torches are currently widely used.

[0005] Existing non-transfer DC plasma torches suffer from the following problems under high current conditions: First, during arc ignition and operation, the arc tends to drift on the electrode surface, making it difficult to stably focus on the central axis of the discharge channel. This leads to arc energy dispersion and exacerbates localized ablation of certain points on the electrodes (especially the cathode), significantly reducing cathode lifespan. Second, traditional cooling methods are insufficient for high power density electrodes, particularly the cathode center, and cannot effectively suppress thermal corrosion. Although existing technologies employ methods such as improving electrode materials, optimizing cooling, or applying external magnetic fields, they often fail to provide systematic optimization in terms of both arc stabilization mechanisms and efficient cooling. Utility Model Content

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0007] In view of the problems existing in the prior art, the present invention is proposed.

[0008] The purpose of this invention is to overcome the problem of low service life of existing DC non-transfer plasma torches and to provide a non-transfer DC arc plasma torch that uses wall-stabilized arc and has three-stage cooling.

[0009] To solve the above technical problems, this utility model provides a non-transfer DC arc plasma torch employing a wall-stabilized arc and equipped with three-stage cooling, comprising a plasma torch body working component and a cooling component. The plasma torch body working component includes a cathode, an anode, a plasma gas channel for introducing working gas, and a cylindrical anode wall stabilizer disposed below the anode. The plasma gas channel is located on the outer periphery of the cathode, and the anode is located on the outer periphery of the plasma gas channel. The lower end of the plasma gas channel communicates with the central hole of the anode wall stabilizer. The cooling component includes independent multi-stage body cooling water channels arranged along the height direction of the plasma torch, and an anode wall stabilizer cooling water channel disposed on the outer periphery of the anode wall stabilizer. The body cooling water channels are located between the outer periphery of the anode and the plasma torch shell.

[0010] Furthermore, the cathode has a cathode center hole with a closed lower end along its axis, and the cathode center hole is divided into multiple segments in the height direction; the cooling water channels of each stage of the body are connected to the cathode center hole through cooling water radial channels.

[0011] Furthermore, the cooling water channel of the main body is configured in three stages along the axial direction of the plasma torch body, with each stage having an independent cooling water inlet and cooling water outlet.

[0012] Furthermore, the anode wall stabilizer cooling water channel is composed of multiple annular grooves disposed on the outer periphery of the anode wall stabilizer and an annular channel outside the annular grooves, and the upper end of the anode wall stabilizer cooling water channel is connected to the upper body cooling water channel.

[0013] Furthermore, the working component of the plasma torch body also includes a forced convection gas channel, the inner port of which is provided with a vortex generator, and the vortex generator communicates with the lower end of the plasma gas channel.

[0014] Furthermore, the working component of the plasma torch body also includes a confinement magnetic coil, which is sleeved on the outer periphery of the anode wall.

[0015] Furthermore, the lower end of the plasma gas channel is tapered and communicates with the central hole of the anode wall.

[0016] Furthermore, the inlets of both the plasma gas channel and the forced convection gas channel are connected to a nitrogen source.

[0017] Compared with the prior art, the advantages or beneficial effects of this utility model include at least the following: 1. High-efficiency zoned cooling: Three-stage cooling water is used to reduce the temperature difference between the cooling water outlet and the cooling water inlet, thereby improving cooling efficiency; the cooling water is introduced into the cathode center hole through radial channels in each stage, further improving the cathode cooling efficiency.

[0018] 2. Arc Stabilization and Compression: The anode wall stabilization structure is adopted in combination with its dedicated cooling water channel. The wall stabilization arc stabilization method provides cooling at the bottom of the anode, i.e., the plasma flow outlet, through the anode wall stabilization cooling water channel. Utilizing the thermal contraction effect of the cold wall, the arc is forcibly constrained to the central axis, effectively increasing the arc length, stabilizing the arc root, and improving the arc power density and stability.

[0019] 3. Multiple Synergistic Stabilizations: The rotating airflow generated by the cyclone generator forces the arc root to move on the electrode surface, preventing excessive local ablation and resulting in a more uniform distribution of plasma torch parameters. The confinement magnetic coil and the wall-stabilizing structure work together to further confine and stabilize the plasma arc column. These measures work together to significantly improve cathode life and the performance of the plasma torch. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein: Figure 1 This is a cross-sectional schematic diagram of a non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling, as described in this utility model. Figure 2 This is a schematic diagram of the anode wall with cooling water in this utility model; Reference numerals: 1. Cathode connector; 2. Anode connector; 3. Plasma gas channel; 4. Body cooling water channel; 5. Anode; 6. Cathode; 7. Forced convection gas flow channel; 8. Swirl; 9. Confinement magnetic coil; 10. Plasma torch housing; 11. Anode wall stabilizer; 12. DC plasma power supply; 13. Anode wall stabilizer cooling water channel. Detailed Implementation

[0021] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0022] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0024] like Figure 1 As shown, this utility model employs a wall-stabilized arc-controlled, non-transfer DC arc plasma torch with three-stage cooling, comprising a plasma torch body working component and a cooling component, wherein: The working components of the plasma torch body include a cathode connector 1, an anode connector 2, a plasma gas channel 3, an anode 5, a cathode 6, a forced convection gas channel 7, a cyclone separator 8, and a confinement magnetic coil 9.

[0025] Cathode connector 1 and anode connector 2 are located at the top of the plasma torch, respectively connected to the anode and cathode of the DC plasma power supply 12. Cathode 6 is a tungsten rod with thorium oxide, its upper end connected to cathode connector 1; the upper end of anode 5 is connected to anode connector 2. Plasma gas channel 3 surrounds cathode 6, and its interface is located at the top of the plasma torch. Forced convection gas channel 7 is located at the bottom of the plasma torch, radially at the bottom of cathode 6. A cyclone separator 8 is installed at the inner port of forced convection gas channel 7, and it communicates with the lower end of ion gas channel 3 through the cyclone separator 8. A confinement magnetic coil 9 is located on the outermost periphery of the bottom outlet of the plasma torch.

[0026] The cooling components include a main body cooling water channel 4 and an anode wall stabilizing cooling water channel 13. The main body cooling water channel 4 is located near the outer periphery of the plasma torch, between the outer wall of the anode 5 and the inner wall of the plasma torch shell 10. The main body cooling water channel 4 has three mutually spaced stages along the height direction of the plasma torch. Each stage of the main body cooling water channel 4 has a cooling water inlet and a cooling water outlet to shorten the flow path of the cooling water in each stage and reduce the temperature difference between the inlet and outlet of the cooling water in each stage. The inlet cooling water of each stage of the main body cooling water channel 4 is 25°C.

[0027] A cathode center hole, closed at its lower end, can be provided along the axis of the cathode 6. This center hole is also divided into three sections along its height. The cooling water inlets and outlets of each stage of the body cooling water channel 4 are connected to the upper part of the cathode center hole via radial cooling water channels. The lower ends of each stage of the body cooling water channel 4 are also connected to the lower part of the cathode center hole via radial cooling water channels. Each radial cooling water channel is sealed at the points where it passes through the anode 5 and the plasma gas channel 3. This allows cooling water to be introduced into the high-temperature center of the cathode 6, resulting in a highly effective cooling effect and further extending the service life of the cathode 6.

[0028] Below the anode 5, there is a cylindrical anode wall stabilizer 11. The lower end of the plasma gas channel 3 is tapered and connected to the central hole of the anode wall stabilizer 11. The lower port of the central hole of the anode wall stabilizer 11 is the gas outlet.

[0029] The constraint magnetic coil 9 is set around the outer periphery of the anode wall stabilizer 11, and an annular channel is provided between it and the outer wall of the anode wall stabilizer 11. Multiple outer annular grooves of the anode wall stabilizer 11 are provided around the outer periphery. Each outer annular groove of the anode wall stabilizer and the annular channel on its outer side together form the anode wall stabilizer cooling water channel 13. The lower end of the anode wall stabilizer cooling water channel 13 is closed, and the water source comes from the upper body cooling water channel 4.

[0030] like Figure 2 As shown, four annular grooves are provided on the outer periphery of the anode wall stabilizer 11 as part of the anode wall stabilizer cooling water channel 13. The anode 5 and cathode 6 of the plasma torch are connected to the DC plasma power supply 12 to form a closed loop.

[0031] The DC plasma power supply 12 uses a DC power supply with a rated power of 50kW and adjustable power to control the temperature of the working gas in the plasma torch.

[0032] The working gas introduced into the plasma gas channel 3 is nitrogen. After nitrogen has been introduced for a period of time, the cathode connector 1 and the anode connector 2 are connected to the DC plasma power supply 12. The plasma heats the working gas under the action of the electric field, making the heated gas a high-temperature gas, which is then ejected from the nozzle of the plasma torch to form a plasma flow.

[0033] The auxiliary gas introduced into the forced convection airflow channel 7 is nitrogen, which provides rotational force to the working gas through the cyclone separator 8.

[0034] The magnetic confinement coil 9 and the anode wall stabilizer 11 are used to confine the diameter of the plasma jet, increase the arc length and power of the plasma arc, and also extend the service life of the cathode 6.

[0035] This invention employs a wall-stabilized arc-controlled, three-stage cooling non-transfer DC arc plasma torch, which has advantages over other plasma torches in the following ways: The working environment of the plasma torch is improved from four aspects: cooling method, external magnetic field, rotating airflow and cathode material. A special three-stage cooling water channel is adopted. An external confinement magnetic coil and a gas cyclone are installed at the bottom of the plasma torch. An anode wall stabilizing cooling water channel 13 is set on the outer periphery of the anode bottom to extend the working life of the plasma torch cathode, improve the arc length and power of the plasma arc and the safety of the plasma torch.

[0036] In summary, this utility model, a non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling, employs cooling water channels, anode-cooled wall-stabilized arc, confinement magnetic coils, and novel plasma torch cathode materials to modify the plasma torch in four aspects. The aim is to improve the lifespan of the plasma torch cathode, enhance the safety of the plasma torch, and increase the arc length and power of the plasma arc. Furthermore, compared to other plasma torches, it is more efficient, safer, and more reliable.

[0037] The above description is merely a preferred embodiment of the present utility model, showing and describing the basic principles, main features, and advantages of the present utility model. It is not intended to limit the scope of patent protection of the present utility model. Those skilled in the art should understand that the present utility model is not limited to the above embodiments. In addition to the above embodiments, the present utility model may have other implementations without departing from the spirit and scope of the present utility model. Various changes and improvements to the present utility model are also possible. All technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present utility model. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents. Technical features not described in the present utility model can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A non-transfer DC arc plasma torch employing wall-stabilized arc and equipped with three-stage cooling, comprising a plasma torch body working component and a cooling component, characterized in that: The plasma torch body working components include a cathode (6), an anode (5), a plasma gas channel (3) for introducing working gas, and a cylindrical anode wall stabilizer (11) disposed below the anode (5). The plasma gas channel (3) is located on the outer periphery of the cathode (6), the anode (5) is located on the outer periphery of the plasma gas channel (3), and the lower end of the plasma gas channel (3) is connected to the central hole of the anode wall stabilizer (11). The cooling components include independent multi-stage body cooling water channels (4) arranged along the height direction of the plasma torch, and an anode wall stabilization cooling water channel (13) arranged on the outer periphery of the anode wall stabilization (11). The body cooling water channel (4) is located between the outer periphery of the anode (5) and the plasma torch shell (10).

2. The non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling as described in claim 1, characterized in that, The cathode (6) has a cathode center hole with a closed lower end along its axis, and the cathode center hole is divided into multiple segments in the height direction; the cooling water channels (4) of each stage are connected to the cathode center hole through the cooling water radial channels.

3. The non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling as described in claim 2, characterized in that, The cooling water channel (4) of the main body is set in three stages along the axial direction of the plasma torch body, and each stage is provided with an independent cooling water inlet and cooling water outlet.

4. The non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling as described in claim 1, characterized in that, The anode wall stabilizer cooling water channel (13) is composed of multiple annular grooves arranged on the outer periphery of the anode wall stabilizer (11) and an annular channel on the outer side of the annular grooves. The upper end of the anode wall stabilizer cooling water channel (13) is connected to the upper body cooling water channel (4).

5. The non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling as described in claim 1, characterized in that, The plasma torch body working component also includes a forced convection gas channel (7), the inner port of which is provided with a vortex generator (8), and is connected to the lower end of the plasma gas channel (3) through the vortex generator (8).

6. The non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling as described in claim 1, characterized in that, The working components of the plasma torch body also include a confinement magnetic coil (9), which is sleeved on the outer periphery of the anode wall stabilizer (11).

7. The non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling as described in claim 1, characterized in that, The lower end of the plasma gas channel (3) is tapered and communicates with the central hole of the anode wall stabilizer (11).

8. The non-transfer DC arc plasma torch with wall-stabilized arc and three-stage cooling as described in claim 5, characterized in that, The inlets of the plasma gas channel (3) and the forced convection gas channel (7) are both connected to a nitrogen source.

Images