A high-power, long-life dual cathode plasma torch device for fly ash melting

Abstract

The invention discloses a high-power, long-life dual-cathode plasma torch device for fly ash melting, comprising a rod-shaped cathode loop assembly, a shielding gas introduction assembly, a cup-shaped cathode loop assembly, a working gas introduction assembly and an anode loop assembly; wherein the rod-shaped cathode loop assembly is embedded in the shielding gas introduction assembly, the shielding gas introduction assembly is embedded in the cup-shaped cathode loop assembly, the cup-shaped cathode loop assembly is embedded in the working gas introduction assembly, and the working gas introduction assembly is embedded in the anode loop assembly. The invention discloses a high-power, long-life dual-cathode plasma torch device for fly ash melting, which can increase the service life of a plasma torch.

Description

Technical Field

[0001] The invention belongs to the technical field of direct current arc plasma torches, and in particular relates to a high-power and long-life dual cathode plasma torch device for melting fly ash. Background Art

[0002] A plasma torch refers to a plasma device that can generate and stably maintain a temperature of 3000-30000K. It has broad application prospects in metallurgy, material surface treatment, welding / cutting, solid waste / hazardous waste treatment and other fields. In the field of DC arc plasma torches, which are widely used, it can be divided into axial plasma torches and coaxial plasma torches. The axial plasma torch is further divided into an axial plasma torch with a central electrode and an axial plasma torch with a cup electrode. The axial plasma torch with a central electrode can obtain a high arc voltage, a high generator power at a relatively low current, and a longer electrode life, and it is easy to obtain a flat or rising volt-ampere characteristic of the plasma arc. The axial plasma torch with a cup electrode can use air as a plasma medium, has a large power, and can easily reach the megawatt level.

[0003] The direct reason that restricts the widespread application of arc plasma torches in the fly ash melting industry is the life problem. The life of an axial plasma torch with a central electrode is generally 500 hours, and the life of an axial plasma torch with a cup electrode is generally 300 hours. At present, researchers generally use methods such as changing electrode materials, optimizing electrode heat transfer methods, and applying external magnetic fields to improve electrode life, but even these methods have not significantly improved the service life of plasma torches. For fly ash melting, it is divided into heating and insulation stages, and the corresponding requirements for plasma torch voltage, current, etc. also change. For an axial plasma torch with a central electrode, the voltage is higher and the current is lower, which is suitable for the insulation stage; for an axial plasma torch with a cup electrode, the current is higher and the voltage is lower, which is suitable for the heating stage. No matter which plasma torch is used, it is necessary to make corresponding adjustments at different stages of fly ash melting, so that the plasma torch works in a non-optimal state, further reducing the service life of the plasma torch. Summary of the invention

[0004] The object of the present invention is to provide a high-power and long-life dual cathode plasma torch device for fly ash melting, which can increase the service life of the plasma torch.

[0005] The technical solution adopted by the present invention is a high-power, long-life dual-cathode plasma torch device for fly ash melting, comprising a rod-shaped cathode loop assembly, a shielding gas introduction assembly, a cup-shaped cathode loop assembly, a working gas introduction assembly and an anode loop assembly; wherein the rod-shaped cathode loop assembly is embedded in the shielding gas introduction assembly, the shielding gas introduction assembly is embedded in the cup-shaped cathode loop assembly, the cup-shaped cathode loop assembly is embedded in the working gas introduction assembly, and the working gas introduction assembly is embedded in the anode loop assembly.

[0006] The present invention is also characterized in that

[0007] The anode loop assembly includes an anode cooling water inlet channel, an anode cooling water return channel, an anode and an anode external electromagnetic coil; wherein the anode cooling water return channel is coaxially sleeved on the outside of the anode cooling water inlet channel, one end opening of the anode cooling water inlet channel is connected with the end of the anode cooling water return channel to form an anode cooling water flow loop, and the anode is installed at one end inside the anode cooling water inlet channel; the interior of the anode is an equal-diameter channel, and the outer wall of the anode is sleeved with an anode external electromagnetic coil; the working gas inlet assembly is coaxially embedded inside the anode cooling water inlet channel.

[0008] The working gas inlet component includes a working gas channel and a working gas cyclone; wherein the working gas channel is coaxially embedded in the inner side of the anode cooling water inlet channel, the end of the working gas channel is connected to the working gas cyclone, and the working gas cyclone is arranged close to the anode; the cup-shaped cathode loop component is coaxially embedded in the inner side of the working gas channel.

[0009] The cup-shaped cathode loop assembly comprises a cup-shaped cathode cooling water inlet channel, a cup-shaped cathode cooling water return channel, a cup-shaped cathode external electromagnetic coil and a cup-shaped cathode; wherein, the cup-shaped cathode cooling water return channel is coaxially embedded in the inner side of the working gas channel, the cup-shaped cathode cooling water inlet channel is coaxially embedded in the inner side of the cup-shaped cathode cooling water return channel, one end opening of the cup-shaped cathode cooling water inlet channel is connected with the end of the cup-shaped cathode cooling water return channel to form a cup-shaped cathode cooling water flow loop, and the cup-shaped cathode is mounted on one end of the inner side of the cup-shaped cathode cooling water inlet channel; the interior of the cup-shaped cathode is an equal-diameter channel, the inner diameter of the inner channel of the cup-shaped cathode is smaller than the inner diameter of the inner channel of the anode, and a cup-shaped cathode external electromagnetic coil is sleeved on the outer wall of the cup-shaped cathode; the protective gas assembly is coaxially embedded in the inner side of the cup-shaped cathode cooling water inlet channel.

[0010] The shielding gas assembly includes a shielding gas channel and a shielding gas cyclone; wherein, the shielding gas channel is coaxially embedded in the inner side of the cup-shaped cathode cooling water inlet channel, the end of the shielding gas channel is connected to the shielding gas cyclone, and the shielding gas cyclone is arranged close to the cup-shaped cathode; the rod-shaped cathode loop assembly is coaxially embedded in the inner side of the shielding gas channel.

[0011] The rod-shaped cathode loop assembly comprises a rod-shaped cathode cooling water inlet channel, a rod-shaped cathode cooling water return channel and a rod-shaped cathode; wherein the rod-shaped cathode cooling water return channel is coaxially embedded in the inner side of the protective gas channel, the rod-shaped cathode cooling water inlet channel is coaxially embedded in the inner side of the rod-shaped cathode cooling water return channel, the rod-shaped cathode is arranged at the end of the rod-shaped cathode cooling water return channel, and the rod-shaped cathode cooling water inlet channel is connected to the end of the rod-shaped cathode cooling water return channel at one side of the opening close to the rod-shaped cathode to form a rod-shaped cathode cooling water flow loop.

[0012] The beneficial effects of the present invention are:

[0013] The device of the present invention aims at the actual working situation that the life of the plasma torch is too short, and proposes a dual cathode plasma torch structure using a rod electrode and a cup electrode combination. The arc-starting electrode is located between the rod cathode and the cup cathode. When working, the airflow between the two cathodes is small, so the gap between them is small, which is helpful for the arc-starting success rate. The life of the cathode of the plasma torch is much shorter than the life of the anode, which causes the service life of the plasma torch to be restricted by the life of the cathode. In the present invention, the arc is first between the rod cathode and the anode, and then switched to between the cup cathode and the anode after the rod electrode reaches its service life. In this way, the life of the plasma torch is the superposition of the rod electrode and the cup electrode, which greatly improves the life of the plasma torch. A magnetic field is added to the outside of the anode, and the magnetic field and the tangential airflow together increase the tangential velocity of the arc root, so that the arc root of the electrode at the anode rotates, avoiding the arc root falling in the same position and increasing the service life of the anode. A magnetic field is added to the outside of the cup electrode. When the arc root falls on the rod-shaped cathode and anode, the magnetic field has a restraining effect on the arc inside the cup electrode, avoiding the ablation of the cup electrode and improving the thermal efficiency of the plasma torch. When the arc root falls on the cup-shaped cathode and anode, the magnetic field and the tangential airflow together drive the cathode arc root to rotate in the cup electrode, avoiding the arc root from falling in the same position and increasing the service life of the cup cathode. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of a rod-shaped cathode in a high-power, long-life dual-cathode plasma torch device for fly ash melting according to the present invention when it is working;

[0015] Figure 2 The present invention is a schematic structural diagram of a cup-shaped cathode in a high-power, long-life dual-cathode plasma torch device for fly ash melting when the cup-shaped cathode is working.

[0016] In the figure, 1. protective gas channel, 2. rod-shaped cathode cooling water inlet channel, 3. rod-shaped cathode cooling water return channel, 4. cup-shaped cathode cooling water inlet channel, 5. cup-shaped cathode cooling water return channel, 6. working gas channel, 7. anode cooling water inlet channel, 8. anode cooling water return channel, 9. rod-shaped cathode, 10. protective cyclone, 11. cup-shaped cathode external electromagnetic coil, 12. cup-shaped cathode, 13. working cyclone, 14. anode, 15. anode external electromagnetic coil. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The present invention provides a high-power and long-life dual cathode plasma torch device for fly ash melting, such as Figure 1-2 As shown, it includes a rod-shaped cathode loop assembly, a shielding gas introduction assembly, a cup-shaped cathode loop assembly, a working gas introduction assembly and an anode loop assembly; wherein, the rod-shaped cathode loop assembly is embedded in the shielding gas introduction assembly, the shielding gas introduction assembly is embedded in the cup-shaped cathode loop assembly, the cup-shaped cathode loop assembly is embedded in the working gas introduction assembly, and the working gas introduction assembly is embedded in the anode loop assembly.

[0019] The anode loop assembly includes an anode cooling water inlet channel 7, an anode cooling water return channel 8, an anode 14 and an anode external electromagnetic coil 15; wherein the anode cooling water return channel 8 is coaxially sleeved on the outside of the anode cooling water inlet channel 7, one end of the anode cooling water inlet channel 7 is open and connected to the end of the anode cooling water return channel 8 to form an anode cooling water flow loop, and the anode 14 is installed at one end of the inner side of the anode cooling water inlet channel 7; the interior of the anode 14 is an equal diameter channel, and the anode external electromagnetic coil 15 is sleeved on the outer wall of the anode 14, the end of the anode cooling water return channel 8 away from the anode 14 is externally connected to the anode terminal, and the anode external electromagnetic coil 15 is externally connected to the power supply; the working gas introduction assembly is coaxially embedded in the inner side of the anode cooling water inlet channel 7. Using a separate cooling water loop to cool the anode 14 helps to improve the cooling effect of the anode 14 and improve the life of the electrode. The anode 14 helps to increase the arc tangential speed and further improve the life of the anode 14.

[0020] The working gas introduction component includes a working gas channel 6 and a working gas cyclone 13; wherein the working gas channel 6 is coaxially embedded in the inner side of the anode cooling water inlet channel 7, the end of the working gas channel 6 is connected to the working gas cyclone 13, and the working gas cyclone 13 is arranged close to the anode 14; the cup-shaped cathode loop component is coaxially embedded in the inner side of the working gas channel 6. The working gas channel 6 and the working gas cyclone 13 are made of insulating materials and together constitute the working gas introduction device, wherein the tangential small holes on the working gas cyclone 13 allow the working gas to enter the discharge channel at a certain tangential speed. The working gas generally uses a gas with low economic value such as air to reduce the use cost of the plasma torch.

[0021] The cup-shaped cathode loop assembly includes a cup-shaped cathode cooling water inlet channel 4, a cup-shaped cathode cooling water return channel 5, a cup-shaped cathode external electromagnetic coil 11 and a cup-shaped cathode 12; wherein, the cup-shaped cathode cooling water return channel 5 is coaxially embedded in the inner side of the working gas channel 6, the cup-shaped cathode cooling water inlet channel 4 is coaxially embedded in the inner side of the cup-shaped cathode cooling water return channel 5, one end of the cup-shaped cathode cooling water inlet channel 4 is opened and connected to the end of the cup-shaped cathode cooling water return channel 5 to form a cup-shaped cathode cooling water flow loop, and the cup-shaped cathode 12 is installed in the inner side of the cup-shaped cathode cooling water inlet channel 4. One end; the interior of the cup-shaped cathode 12 is an equal-diameter channel, the inner diameter of the inner channel of the cup-shaped cathode 12 is smaller than the inner diameter of the inner channel of the anode 14, a cup-shaped cathode external electromagnetic coil 11 is sleeved on the outer wall of the cup-shaped cathode 12, the cup-shaped cathode cooling water return channel 5 is connected to the cathode terminal at one end away from the cup-shaped cathode 12, and the cup-shaped cathode external electromagnetic coil 11 is connected to an external power supply; the protective gas component is coaxially embedded in the inner side of the cup-shaped cathode cooling water inlet channel 4; a separate cooling water loop is used to cool the cup-shaped cathode 12, which helps to improve the cooling effect of the cup-shaped cathode 12 and improve the life of the electrode. The external magnetic field applied by the cup-shaped cathode external electromagnetic coil 11 helps to increase the arc tangential velocity or the thermal efficiency of the plasma torch, and further improves the life of the cup-shaped electrode 12.

[0022] The shielding gas assembly includes a shielding gas channel 1 and a shielding gas cyclone 10; wherein the shielding gas channel 1 is coaxially embedded in the inner side of the cup-shaped cathode cooling water inlet channel 4, the end of the shielding gas channel 1 is connected to the shielding gas cyclone 10, and the shielding gas cyclone 10 is arranged close to the cup-shaped cathode 12; the rod-shaped cathode loop assembly is coaxially embedded in the inner side of the shielding gas channel 1. The shielding gas channel 1 and the shielding gas cyclone 10 are made of insulating materials and together constitute a shielding gas introduction device, wherein the tangential small holes on the shielding gas cyclone 10 allow the shielding gas to enter the discharge channel at a certain tangential speed. The shielding gas generally uses nitrogen or other inert gases to increase the service life of the rod-shaped cathode 9.

[0023] The rod-shaped cathode loop assembly comprises a rod-shaped cathode cooling water inlet channel 2, a rod-shaped cathode cooling water return channel 3 and a rod-shaped cathode 9; wherein, the rod-shaped cathode cooling water return channel 3 is coaxially embedded in the inner side of the protective gas channel 1, the rod-shaped cathode cooling water inlet channel 2 is coaxially embedded in the inner side of the rod-shaped cathode cooling water return channel 3, the rod-shaped cathode 9 is arranged at the end of the rod-shaped cathode cooling water return channel 3, the opening of the rod-shaped cathode cooling water inlet channel 2 close to the rod-shaped cathode 9 is connected to the end of the rod-shaped cathode cooling water return channel 3 to form a rod-shaped cathode cooling water flow loop; using a separate cooling water loop to cool the rod-shaped electrode 9 helps to improve the cooling effect of the rod-shaped electrode 9 and improve the electrode life; the end of the rod-shaped cathode cooling water return channel 3 away from the rod-shaped cathode 9 is externally connected to the cathode terminal.

[0024] The scene when the rod cathode 9 is working is as follows Figure 1 As shown, the arc root falls on the rod-shaped cathode 9 and the anode 14, and at this time, the plasma torch arc voltage is relatively high and the current is relatively low.

[0025] The scene when the cup cathode 12 is working is as follows Figure 2 As shown, the arc root falls on the cup-shaped cathode 12 and the anode 14, and at this time, the plasma torch arc voltage is low and the current is high.

[0026] The inner diameter of the cup-shaped cathode arc channel is smaller than the inner diameter of the anode arc channel, and the anode head has an arc, so that the working gas can smoothly enter the anode arc channel.

[0027] The advantages of the present invention are:

[0028] (1) The arc-starting electrode is located between the rod-shaped cathode and the cup-shaped cathode. During operation, the airflow between the two cathodes is small, so the gap between them is small, which helps to increase the arc-starting success rate. The cathode life of a plasma torch is much shorter than the anode life, which results in the service life of the plasma torch being restricted by the cathode life. In the device of the present invention, the arc is first between the rod-shaped cathode and the anode, and then switched to between the cup-shaped cathode and the anode after the rod-shaped electrode reaches its service life. In this way, the life of the plasma torch is the superposition of the rod-shaped electrode and the cup-shaped electrode, which greatly improves the life of the plasma torch. A magnetic field is added to the outside of the anode. The magnetic field and the tangential airflow together increase the tangential velocity of the arc root, causing the arc root of the electrode at the anode to rotate, thereby preventing the arc root from falling in the same position and increasing the service life of the anode. A magnetic field is added to the outside of the cup electrode. When the arc root falls on the rod-shaped cathode and anode, the magnetic field has a restraining effect on the arc inside the cup electrode, avoiding the ablation of the cup electrode and improving the thermal efficiency of the plasma torch. When the arc root falls on the cup-shaped cathode and anode, the magnetic field and the tangential airflow together drive the cathode arc root to rotate in the cup electrode, avoiding the arc root from falling in the same position and increasing the service life of the cup cathode.

[0029] (2) The device combines an axial plasma torch with a central electrode and an axial plasma torch with a cup electrode. The rod electrode is used in the heat preservation stage and the cup electrode is used in the heating stage. Not only does the plasma torch work in the best state, but the service life of the plasma torch can also be increased. The device is easy to use and low in cost, and can greatly increase the service life of the plasma torch.

[0030] (3) The straight arc-starting electrode is located between the rod-shaped cathode and the cup-shaped cathode. During operation, the air flow between the two cathodes is small, so the gap between them is small, which helps to increase the arc-starting success rate.

Claims

1. A high-power, long-life dual cathode plasma torch device for fly ash melting, characterized in that: It includes a rod-shaped cathode loop assembly, a shielding gas introduction assembly, a cup-shaped cathode loop assembly, a working gas introduction assembly and an anode loop assembly; wherein the rod-shaped cathode loop assembly is embedded in the shielding gas introduction assembly, the shielding gas introduction assembly is embedded in the cup-shaped cathode loop assembly, the cup-shaped cathode loop assembly is embedded in the working gas introduction assembly, and the working gas introduction assembly is embedded in the anode loop assembly; The anode loop assembly comprises an anode cooling water inlet channel (7), an anode cooling water return channel (8), an anode (14) and an anode external electromagnetic coil (15); wherein the anode cooling water return channel (8) is coaxially sleeved on the outside of the anode cooling water inlet channel (7); an opening at one end of the anode cooling water inlet channel (7) is connected to the end of the anode cooling water return channel (8) to form an anode cooling water flow loop; the anode (14) is mounted on one end of the inner side of the anode cooling water inlet channel (7); the interior of the anode (14) is a channel of equal diameter; the outer wall of the anode (14) is sleeved with an anode external electromagnetic coil (15); the working gas inlet assembly is coaxially embedded on the inner side of the anode cooling water inlet channel (7); The working gas inlet assembly comprises a working gas channel (6) and a working gas cyclone (13); wherein the working gas channel (6) is coaxially embedded inside the anode cooling water inlet channel (7), the end of the working gas channel (6) is connected to the working gas cyclone (13), and the working gas cyclone (13) is arranged close to the anode (14); and the cup-shaped cathode loop assembly is coaxially embedded inside the working gas channel (6); The cup-shaped cathode loop assembly comprises a cup-shaped cathode cooling water inlet channel (4), a cup-shaped cathode cooling water return channel (5), a cup-shaped cathode external electromagnetic coil (11) and a cup-shaped cathode (12); wherein the cup-shaped cathode cooling water return channel (5) is coaxially embedded inside the working gas channel (6), the cup-shaped cathode cooling water inlet channel (4) is coaxially embedded inside the cup-shaped cathode cooling water return channel (5), and one end of the cup-shaped cathode cooling water inlet channel (4) is open to the cup-shaped cathode. The ends of the cooling water return channel (5) are connected to form a cup-shaped cathode cooling water flow loop, and the cup-shaped cathode (12) is installed at one end of the inner side of the cup-shaped cathode cooling water inlet channel (4); the interior of the cup-shaped cathode (12) is an equal-diameter channel, the inner diameter of the inner channel of the cup-shaped cathode (12) is smaller than the inner diameter of the inner channel of the anode (14), and a cup-shaped cathode external electromagnetic coil (11) is sleeved on the outer wall of the cup-shaped cathode (12); the protective gas component is coaxially embedded in the inner side of the cup-shaped cathode cooling water inlet channel (4); The shielding gas assembly comprises a shielding gas channel (1) and a shielding gas cyclone (10); wherein the shielding gas channel (1) is coaxially embedded inside the cup-shaped cathode cooling water inlet channel (4), the end of the shielding gas channel (1) is connected to the shielding gas cyclone (10), and the shielding gas cyclone (10) is arranged close to the cup-shaped cathode (12); the rod-shaped cathode loop assembly is coaxially embedded inside the shielding gas channel (1); The rod-shaped cathode loop assembly comprises a rod-shaped cathode cooling water inlet channel (2), a rod-shaped cathode cooling water return channel (3) and a rod-shaped cathode (9); wherein the rod-shaped cathode cooling water return channel (3) is coaxially embedded in the inner side of the protective gas channel (1), the rod-shaped cathode cooling water inlet channel (2) is coaxially embedded in the inner side of the rod-shaped cathode cooling water return channel (3), the rod-shaped cathode (9) is arranged at the end of the rod-shaped cathode cooling water return channel (3), and the opening of the rod-shaped cathode cooling water inlet channel (2) close to the rod-shaped cathode (9) is connected to the end of the rod-shaped cathode cooling water return channel (3) to form a rod-shaped cathode cooling water flow loop.

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