Direct-current arc plasma furnace

Abstract

The direct-current arc plasma furnace comprises a furnace body and a furnace cover arranged at the top of the furnace body, a negative electrode with the lower end extending into the furnace body is arranged in the center of the furnace cover, a plasma torch generating device with the lower end extending into the furnace body is arranged on the furnace cover, a feeding port is formed in the furnace cover, and a waste gas discharging port is formed in the upper portion of the furnace body. A molten liquid outlet and an iron outlet are formed in the lower portion of the furnace body, and the iron outlet is lower than the molten liquid outlet. The combustion-supporting furnace is scientific in principle, compact in structure and high in safety, the combustion-supporting range completely covers the internal area of the furnace body, crusting is avoided, waste incineration is more sufficient, the combustion efficiency is high, and more energy is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of electric arc furnaces, and in particular relates to a direct current arc plasma furnace. Background Art

[0002] The DC arc furnace used in waste incineration is a type of industrial electric furnace. Currently, there are the following technical problems in practical application: (1) The furnace cover of the electric furnace is round, and an electrode hole for passing the ignition electrode is opened in the center of the furnace cover. The ignition and combustion of the electric furnace mainly rely on the ignition electrode. This ignition and combustion method makes the garbage near the center of the furnace body burn more efficiently and burn more completely. The garbage around the furnace body has a relatively low combustion efficiency and does not burn very completely, which affects the efficiency of garbage incineration and wastes more electricity.

[0003] (2) Traditional DC arc furnaces only rely on the arc generated between the positive electrode and the negative electrode. After the molten material is melted in the furnace body, it is very easy to form a crust on the upper part of the inner wall of the furnace body and block the feed port. It is difficult for the material to enter the furnace body from the feed port of the furnace cover, resulting in empty burning in the furnace body. Once the molten material flows out, the furnace body will be burned, causing serious accidents and economic losses. Summary of the invention

[0004] In order to solve the above technical problems existing in the prior art, the present invention provides a DC arc plasma furnace which has high incineration efficiency, avoids crusting, has good heat insulation performance and is energy-saving.

[0005] In order to solve the above technical problems, the present invention adopts the following technical scheme: a DC arc plasma furnace, comprising a furnace body and a furnace cover arranged on the top of the furnace body, a cathode electrode is arranged at the center of the furnace cover, the furnace cover is provided with a plasma torch generating device with its lower end extending into the furnace body, a feed port is arranged on the furnace cover, a waste gas discharge port is arranged on the upper part of the furnace body, a molten liquid outlet and an iron outlet are arranged at the lower part of the furnace body, and the iron outlet is located lower than the molten liquid outlet.

[0006] The inner wall of the furnace body is provided with a crucible with an open top, and the bottom of the furnace body is provided with at least two anode electrodes passing through the furnace body and the bottom of the crucible. The anode electrodes are arranged in a circular array around the center line of the cathode electrode.

[0007] A water cooling circulation pipeline system is arranged outside the furnace body.

[0008] There are a plurality of plasma torch generating devices, and the plurality of plasma torch generating devices are arranged in an array around the circumference of the cathode electrode; Each plasma torch generating device includes a plasma generator and a hinge support fixed on the top of the furnace cover, a mounting shell is rotatably connected to the hinge support, the interior of the mounting shell is filled with refractory material, a fixing plate is provided on the bottom around the mounting shell, the fixing plate is connected to the furnace cover by mounting bolts, a water-cooling sleeve assembly is provided on the top of the mounting shell, and combustion-supporting holes which are transparent from top to bottom are correspondingly opened on the mounting shell, the refractory material and the furnace cover, the upper port of the combustion-supporting hole is connected to the interior of the water-cooling sleeve assembly, and the plasma generator is arranged inside the water-cooling sleeve assembly.

[0009] The water-cooling sleeve assembly includes an outer cylinder, a heat insulation plate fitted with the top surface of the furnace cover is provided at the lower end of the outer cylinder, a through hole corresponding to the combustion-supporting hole is opened on the heat insulation plate, an annular positioning sleeve is provided on the top surface of the furnace cover, the lower end of the outer cylinder is interference fitted and welded in the positioning sleeve, a spiral water-cooling pipe is provided in the circumferential direction of the inner circle of the outer cylinder, a cylinder cover is provided at the upper end of the outer cylinder, a cold water inlet pipe passing through the outer cylinder is provided at the lower end of the water-cooling pipe, a water outlet pipe passing through the cylinder cover is provided at the upper end of the water-cooling pipe, a plasma generator is coaxially installed in the spiral water-cooling pipe, and a nozzle at the lower end of the plasma generator extends into the combustion-supporting hole.

[0010] The feed inlet is arranged outside the plasma generator, and a plurality of the feed inlets are provided, and the plurality of feed inlets are arranged in an array around the circumference of the cathode electrode.

[0011] By adopting the above technical solution, compared with the prior art, the present invention has the following technical effects: (1) The present invention uses direct current as energy and utilizes the arc generated between the cathode electrode and the anode electrode to generate heat, thereby achieving the purpose of smelting. The anode electrode at the bottom of the furnace body plays the role of guiding current, stabilizing the arc and regulating voltage. A cathode electrode (negative electrode) is arranged in the center of the upper part (furnace cover), and at least two anode electrodes (positive electrodes) are arranged in a circular array around the cathode electrode at the bottom of the furnace body, so that the generated arc covers a larger space and improves the incineration efficiency.

[0012] (2) A plurality of plasma torch generating devices are arranged in an array around the center circumference of the cathode electrode on the furnace cover. Combined with the characteristic that the DC plasma arc generally generates an arc at the bottom of the furnace body, and combined with the high-temperature arc generated by the plasma generator, a plurality of plasma generators are opened on the furnace cover. The problem that the material crust on the upper inner wall of the crucible inside the furnace body cannot be discharged is solved by spraying the plasma torch arc to melt the crusted material, so that the problem of crusting of the molten material in the furnace body is completely solved. This not only solves the problem of material crusting in the furnace, but also increases the melting speed of the material outside the furnace body that is not radiated by the arc generated by the electrode, thereby improving production efficiency and completely solving the safety accidents and economic losses caused by the furnace body burning dry.

[0013] (3) Several feed ports are evenly arranged on the furnace cover, so that the feed to each area in the furnace body can be more uniform.

[0014] (4) Since the specific gravity of molten iron after melting is greater than that of molten garbage, the tapping hole is located lower than the molten liquid outlet.

[0015] (5) A water cooling circulation pipeline system is set on the outside of the furnace body to reduce the furnace temperature and extend the service life of the furnace body.

[0016] (6) The refractory material installed in the installation shell is the first barrier to protect the normal operation of the plasma generator. The water-cooling sleeve assembly surrounds the plasma generator and cools the plasma generator by water cooling, which is the second barrier to protect the normal operation of the plasma generator.

[0017] When inspecting the nozzle of the plasma igniter, the mounting bolts can be removed, and the mounting shell, plasma generator and water-cooling sleeve assembly can be lifted up with the hinge support as the fulcrum. The positioning sleeve is fixed on the top of the mounting shell, and the outer cylinder of the water-cooling sleeve assembly is interference-fitted in the positioning sleeve, and the outer cylinder is welded to the positioning sleeve. The water-cooling pipe is set along the outer circle of the plasma generator, and cold water is introduced into the cold water inlet pipe at the bottom. After cooling the plasma generator (after heat exchange), the hot water is discharged through the water outlet pipe at the top. In this way, the circulating water cooling has a good cooling effect, ensuring that the plasma generator works in a lower temperature working environment and prolonging its service life.

[0018] In summary, the present invention has a scientific principle, a compact structure, high safety, and a combustion-supporting range that fully covers the internal area of ​​the furnace body, and no longer has crusting, so that the garbage can be incinerated more fully, the combustion efficiency is high, and it is more energy-saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 A magnified view of the plasma torch generator and water-cooling sleeve assembly. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and examples.

[0021] Figure 1 and Figure 2 As shown, a DC arc plasma furnace of the present invention comprises a furnace body 1 and a furnace cover 2 arranged on the top of the furnace body 1, a cathode electrode 3 is provided at the center of the furnace cover 2, the lower end of which extends into the furnace body 1, a plasma torch generating device 4 is provided on the furnace cover 2, the lower end of which extends into the furnace body 1, a feed port 5 is provided on the furnace cover 2, an exhaust gas discharge port 6 is provided on the upper part of the furnace body 1, a molten liquid outlet 7 and an iron outlet 8 are provided at the lower part of the furnace body 1, and the iron outlet 8 is located lower than the molten liquid outlet 7.

[0022] The inner wall of the furnace body 1 is provided with a crucible 9 (a container for melting metal or other substances, made of refractory materials such as clay and graphite) with an open top, and the bottom of the furnace body 1 is provided with at least two anode electrodes 10 passing through the furnace body 1 and the bottom of the crucible 9. The anode electrodes 10 are arranged in a circular array around the center line of the cathode electrode 3.

[0023] A water cooling circulation pipeline system 11 (existing conventional technology) is provided outside the furnace body 1 .

[0024] There are a plurality of plasma torch generating devices 4, and the plurality of plasma torch generating devices 4 are arranged in a circular array around the cathode electrode 3; Each plasma torch generating device 4 includes a plasma generator 12 and a hinge support 13 fixed on the top of the furnace cover 2, a mounting shell 14 is rotatably connected to the hinge support 13, the interior of the mounting shell 14 is filled with refractory material 15, a fixing plate 16 is provided at the bottom around the mounting shell 14, the fixing plate 16 is connected to the furnace cover 2 by mounting bolts, a water-cooling sleeve assembly is provided on the top of the mounting shell 14, and combustion-supporting holes 17 that are transparent from top to bottom are correspondingly opened on the mounting shell 14, the refractory material 15 and the furnace cover 2, the upper end of the combustion-supporting hole 17 is connected to the interior of the water-cooling sleeve assembly, and the plasma generator 12 is arranged inside the water-cooling sleeve assembly.

[0025] The water-cooling sleeve assembly includes an outer cylinder 18, a heat insulation plate 19 is provided at the lower end of the outer cylinder 18, and the heat insulation plate 19 is provided with a through hole corresponding to the combustion-supporting hole 17. An annular positioning sleeve 20 is provided on the top surface of the furnace cover 2. The lower end of the outer cylinder 18 is interference fitted and welded in the positioning sleeve 20. A spiral water-cooling pipe 21 is provided along the circumferential direction of the inner circle of the outer cylinder 18. A cylinder cover 22 is provided at the upper end of the outer cylinder 18. A cold water inlet pipe 23 passing through the outer cylinder 18 is provided at the lower end of the water-cooling pipe 21. A water outlet pipe 24 passing through the cylinder cover 22 is provided at the upper end of the water-cooling pipe 21. The plasma generator 12 is coaxially installed in the spiral water-cooling pipe 21, and the nozzle at the lower end of the plasma generator 12 extends into the combustion-supporting hole 17.

[0026] The feed inlet 5 is disposed outside the plasma generator 12 . There are a plurality of feed inlets 5 , and the plurality of feed inlets 5 are arranged in a circular array around the cathode electrode 3 .

[0027] The working principle and technical effects of the present invention are as follows: (1) The present invention uses direct current as energy and utilizes the arc generated between the cathode electrode 3 and the anode electrode 10 to generate heat, thereby achieving the purpose of smelting. The anode electrode 10 at the bottom of the furnace body 1 plays the role of guiding current, stabilizing the arc and regulating voltage. A cathode electrode 3 (negative electrode) is arranged at the center of the upper part (furnace cover 2), and at least two anode electrodes 10 (positive electrodes) are arranged in a circular array around the cathode electrode 3 at the bottom of the furnace body 1, so that the space covered by the generated arc is larger, thereby improving the incineration efficiency.

[0028] (2) A plurality of plasma torch generating devices 4 are arranged in an array around the central circumference of the cathode electrode 3 on the furnace cover 2. In view of the characteristic that the DC plasma arc generally generates an arc at the bottom of the furnace body 1, and in view of the high-temperature arc generated by the plasma generator 12, a plurality of plasma generators 12 are provided on the furnace cover 2. To solve the problem that the material on the upper inner wall of the crucible 9 inside the furnace body 1 is crusted and cannot be discharged, the plasma torch arc sprays and melts the crusted material, so that the problem of crusting of the molten material in the furnace body 1 is completely solved. This not only solves the problem of crusting of the material in the furnace, but also increases the melting speed of the material outside the furnace body 1 that is not radiated by the arc generated by the electrode, thereby improving production efficiency and completely solving the safety accidents and economic losses caused by the burning out of the furnace body 1.

[0029] (3) A plurality of feed openings 5 ​​are evenly arranged on the furnace cover 2, so that the feed to each area in the furnace body 1 can be more even.

[0030] (4) Since the specific gravity of the molten iron after melting is greater than that of the molten garbage, the iron outlet 8 is located lower than the molten liquid outlet 7.

[0031] (5) A water cooling circulation pipeline system 11 is arranged outside the furnace body 1 to reduce the temperature of the furnace body 1 and extend the service life of the furnace body 1.

[0032] (6) The refractory material 15 disposed in the mounting shell 14 is the first barrier to protect the normal operation of the plasma generator 12. The water-cooling sleeve assembly surrounds the plasma generator 12 and cools the plasma generator 12 by water cooling, which is the second barrier to protect the normal operation of the plasma generator 12.

[0033] When inspecting the nozzle of the plasma igniter, the mounting bolts can be removed, and the mounting shell 14, the plasma generator 12 and the water-cooling sleeve assembly can be lifted up with the hinge support 13 as the fulcrum. The positioning sleeve 20 is fixed on the top of the mounting shell 14, and the outer cylinder 18 of the water-cooling sleeve assembly is interference-fitted in the positioning sleeve 20, and the outer cylinder 18 is welded to the positioning sleeve 20. The water-cooling pipe 21 is arranged along the outer circle of the plasma generator 12, and the cold water inlet pipe 23 at the bottom is passed with cold water. The hot water after cooling the plasma generator 12 (after heat exchange) is discharged through the water outlet pipe 24 at the top. In this way, the circulating water cooling has a good cooling effect, ensuring that the plasma generator 12 works in a relatively low temperature working environment and prolonging the service life.

[0034] The cathode electrode 3, the anode electrode 10 and the plasma generator 12 in the present invention are all existing mature technologies and can be purchased on the market, so their structures and working principles are not described in detail.

[0035] The above embodiments illustrate the basic principles and features of the present invention, but the above only illustrates the preferred embodiments of the present invention and is not limited to the embodiments. Under the inspiration of this patent, a person skilled in the art can make many forms of deformation and improvement without departing from the scope of protection of the present invention and the claims, which are all within the protection scope of the present invention. Therefore, the patent and protection scope of the present invention shall be subject to the attached claims.

Claims

1. A DC arc plasma furnace, comprising a furnace body and a furnace cover arranged on the top of the furnace body, characterized in that: A cathode electrode is provided at the center of the furnace cover, the lower end of which extends into the furnace body; a plasma torch generating device is provided on the furnace cover, the lower end of which extends into the furnace body; a feed port is provided on the furnace cover, a waste gas discharge port is provided on the upper part of the furnace body, a molten liquid outlet and an iron outlet are provided on the lower part of the furnace body, and the iron outlet is located lower than the molten liquid outlet.

2. A DC arc plasma furnace according to claim 1, characterized in that: The inner wall of the furnace body is provided with a crucible with an open top, and the bottom of the furnace body is provided with at least two anode electrodes passing through the furnace body and the bottom of the crucible. The anode electrodes are arranged in a circular array around the center line of the cathode electrode.

3. A DC arc plasma furnace according to claim 1 or 2, characterized in that: A water cooling circulation pipeline system is arranged outside the furnace body.

4. A DC arc plasma furnace according to claim 1 or 2, characterized in that: There are a plurality of plasma torch generating devices, and the plurality of plasma torch generating devices are arranged in an array around the circumference of the cathode electrode; Each plasma torch generating device includes a plasma generator and a hinge support fixed on the top of the furnace cover, a mounting shell is rotatably connected to the hinge support, the interior of the mounting shell is filled with refractory material, a fixing plate is provided on the bottom around the mounting shell, the fixing plate is connected to the furnace cover by mounting bolts, a water-cooling sleeve assembly is provided on the top of the mounting shell, and combustion-supporting holes which are transparent from top to bottom are correspondingly opened on the mounting shell, the refractory material and the furnace cover, the upper port of the combustion-supporting hole is connected to the interior of the water-cooling sleeve assembly, and the plasma generator is arranged inside the water-cooling sleeve assembly.

5. A DC arc plasma furnace according to claim 4, characterized in that: The water-cooling sleeve assembly includes an outer cylinder, a heat insulation plate fitted with the top surface of the furnace cover is provided at the lower end of the outer cylinder, a through hole corresponding to the combustion-supporting hole is opened on the heat insulation plate, an annular positioning sleeve is provided on the top surface of the furnace cover, the lower end of the outer cylinder is interference fitted and welded in the positioning sleeve, a spiral water-cooling pipe is provided in the circumferential direction of the inner circle of the outer cylinder, a cylinder cover is provided at the upper end of the outer cylinder, a cold water inlet pipe passing through the outer cylinder is provided at the lower end of the water-cooling pipe, a water outlet pipe passing through the cylinder cover is provided at the upper end of the water-cooling pipe, a plasma generator is coaxially installed in the spiral water-cooling pipe, and a nozzle at the lower end of the plasma generator extends into the combustion-supporting hole.

6. A DC arc plasma furnace according to claim 1 or 2, characterized in that: The feed inlet is arranged outside the plasma generator, and a plurality of the feed inlets are provided, and the plurality of feed inlets are arranged in an array around the circumference of the cathode electrode.

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