Mixed type plasma electric arc furnace

Abstract

The electric furnace comprises a furnace body and a furnace cover arranged at the top, an electrode hole is formed in the center of the furnace cover, an ignition electrode is inserted into the electrode hole, a plurality of plasma combustion devices are arranged on the furnace cover, and the plasma combustion devices are evenly arranged along the circumference of the furnace cover. The ignition electrode is arranged in the center of the furnace cover, and the multiple plasma combustion devices are evenly arranged on the outer edge of the furnace cover to support combustion of garbage on the inner edge and the outer edge of the furnace body, so that the garbage incineration efficiency is improved, and garbage incineration is more sufficient. The plasma combustion device adopts a mode of bottom heat insulation and circumferential water cooling to ensure that the plasma generator is at a good working temperature.

Description

Technical Field

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

[0002] The waste incineration electric arc furnace is a type of industrial electric furnace. 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 waste near the center of the furnace body burn efficiently and burn more fully. The waste around the furnace body has a relatively low combustion efficiency and is not burned very fully, which affects the waste incineration efficiency and wastes more electricity. In addition, the traditional plasma DC furnace only relies on the arc generated between the positive electrode and the negative electrode, and the traditional DC plasma arc furnace generates an arc inside the furnace body. After the material is melted, it is very easy to form a crust on the upper part of the inner wall of the furnace body, which makes it impossible for the material to enter the furnace body from the feed port of the furnace cover, resulting in empty burning. Once the melt is drained, the furnace body will be burned, causing serious accidents and economic losses.

[0003] Therefore, there is an urgent need to optimize and improve the existing electric arc furnace structure. Summary of the invention

[0004] In order to solve the above technical problems existing in the prior art, the present invention provides a hybrid plasma arc furnace in which an ion generator is arranged along the center of the furnace cover to assist combustion of garbage around the outer circle inside the furnace body to improve the incineration efficiency and avoid crusting.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: a hybrid plasma arc furnace, the electric furnace includes a furnace body and a furnace cover arranged on the top, an electrode hole is opened in the center of the furnace cover, an ignition electrode is inserted in the electrode hole, and a plurality of plasma combustion devices are arranged on the furnace cover, and the plurality of plasma combustion devices are evenly arranged along the circumference of the furnace cover.

[0006] The furnace cover includes a central disc part and six sector-shaped parts. The central angle of each sector-shaped part is 60°. The six sector-shaped parts are evenly arranged along the outer circle of the disc part. The electrode hole is opened in the center of the disc part. A plasma combustion device is provided on each of the six sector-shaped parts, and two of the sector-shaped parts are also provided with a feed port and a smoke exhaust port.

[0007] The plasma combustion device includes 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 bricks, a fixing plate is provided at the bottom around the mounting shell, the fixing plate is connected to the furnace cover through mounting bolts, a water-cooling sleeve assembly is provided on the top of the mounting shell, and combustion-supporting holes that are transparent from top to bottom are correspondingly opened on the mounting shell, the refractory bricks 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.

[0008] The water-cooling sleeve assembly includes an outer cylinder, a heat insulation plate fitted with the top surface of the mounting shell 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 of the mounting shell, the lower end of the outer cylinder is interference fitted in the positioning sleeve, a spiral water-cooling pipe is provided on the inner circle of the outer cylinder along the circumferential direction, 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.

[0009] By adopting the above technical solution, the present invention has the following technical effects: 1) The refractory bricks installed in the installation shell are 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.

[0010] 2) The ignition and combustion in the center of the furnace body relies on the ignition electrode, and the combustion outside the furnace body relies on the plasma generator. This basically covers the entire internal space of the furnace body, greatly improving the combustion efficiency and making the garbage in the furnace body burn more fully.

[0011] 3) When inspecting the nozzle of the ion 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. The outer cylinder is then welded to the positioning sleeve. The water cooling pipe is set along the outer circle of the plasma generator. Cold water is introduced into the cold water inlet pipe at the bottom, and the hot water after heat exchange is discharged through the water outlet pipe at the top, which has a good cooling effect and ensures that the plasma generator has a good working environment.

[0012] 4) Combined with the characteristics of DC plasma arc that generally generates arc at the bottom of the furnace body, combined with the high-temperature arc generated by the transferred arc plasma torch, multiple plasma generators are opened from the furnace cover to solve the problem that the material in the upper part of the furnace body cannot be unloaded due to crusting. The plasma torch arc sprays and melts the crusted material, so that the problem of material crusting in the furnace body is completely solved. In this way, not only the problem of material crusting in the furnace is solved, but also the material melting speed can be increased, the production efficiency can be improved, and the safety accidents and economic losses caused by the furnace body burning dry can be completely solved.

[0013] In summary, the present invention arranges an ignition electrode in the center of the furnace cover and evenly arranges multiple plasma combustion devices on the outer edge to assist the combustion of garbage at the inner and outer edges of the furnace body, thereby improving the incineration efficiency of garbage and making the garbage incineration more complete. The plasma combustion device adopts the method of bottom insulation and circumferential water cooling to ensure that the plasma generator is at a good working temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the top view of the structure of the present invention; Figure 2 It is a schematic diagram of the vertical cross-sectional structure of the furnace cover in the present invention; Figure 3 yes Figure 2 A magnified view of the plasma combustion device. DETAILED DESCRIPTION

[0015] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and examples.

[0016] Figure 1-Figure 3 As shown, a hybrid plasma arc furnace of the present invention comprises a furnace body (not shown, conventional and unimproved) and a furnace cover arranged on the top, an electrode hole 2 is opened in the center of the furnace cover, an ignition electrode (not shown, conventional and unimproved) is inserted in the electrode hole 2, and a plurality of plasma combustion devices 3 are arranged on the furnace cover, and the plurality of plasma combustion devices 3 are evenly arranged along the circumference of the furnace cover.

[0017] The furnace cover includes a central disc portion 4 and six sector-shaped portions 5. The central angle of each sector-shaped portion 5 is 60°. The six sector-shaped portions 5 are evenly arranged along the outer circle of the disc portion 4. The electrode hole 2 is opened in the center of the disc portion 4. A plasma combustion device 3 is respectively provided on the six sector-shaped portions 5, and two of the sector-shaped portions 5 are also provided with a feed port 6 and a smoke exhaust port 7, respectively.

[0018] The plasma combustion device 3 includes a hinge support 8 fixed on the top of the furnace cover, a mounting shell 9 is rotatably connected to the hinge support 8, the mounting shell 9 is filled with refractory bricks 10, a fixing plate 11 is provided at the bottom around the mounting shell 9, the fixing plate 11 is connected to the furnace cover by mounting bolts, a water-cooling sleeve assembly is provided on the top of the mounting shell 9, and combustion-supporting holes 12 that are transparent from top to bottom are correspondingly opened on the mounting shell 9, the refractory bricks 10 and the furnace cover, the upper port of the combustion-supporting hole 12 is connected to the inside of the water-cooling sleeve assembly, and a plasma generator 13 is arranged inside the water-cooling sleeve assembly.

[0019] The water-cooling sleeve assembly includes an outer cylinder 14, a heat insulation plate 15 is provided at the lower end of the outer cylinder 14, which is fitted with the top surface of the mounting shell 9, and a through hole corresponding to the combustion-supporting hole 12 is opened on the heat insulation plate 15. An annular positioning sleeve 16 is provided on the top of the mounting shell 9, and the lower end of the outer cylinder 14 is interference-fitted in the positioning sleeve 16. A spiral water-cooling pipe 17 is provided along the circumferential direction of the inner circle of the outer cylinder 14, and a cylinder cover 18 is provided at the upper end of the outer cylinder 14. A cold water inlet pipe 19 is provided at the lower end of the water-cooling pipe 17 passing through the outer cylinder 14, and a water outlet pipe 20 passing through the cylinder cover 18 is provided at the upper end of the water-cooling pipe 17. The plasma generator 13 is coaxially installed in the spiral water-cooling pipe 17, and the nozzle at the lower end of the plasma generator 13 extends into the combustion-supporting hole 12.

[0020] The working principle and technical effects of the present invention are as follows: 1) The refractory bricks 10 disposed in the mounting shell 9 are the first barrier to protect the normal operation of the plasma generator 13. The water-cooling sleeve assembly surrounds the plasma generator 13 and cools the plasma generator 13 by water cooling, which is the second barrier to protect the normal operation of the plasma generator 13.

[0021] 2) The ignition and combustion in the center of the furnace body relies on the ignition electrode, and the combustion outside the furnace body relies on the plasma generator 13, so that the entire internal space of the furnace body is basically covered, the combustion efficiency is greatly improved, and the garbage in the furnace body is burned more fully.

[0022] 3) When inspecting the nozzle of the ion igniter, the mounting bolts can be removed, and the mounting shell 9, plasma generator 13 and water cooling sleeve assembly can be lifted up with the hinge support 8 as the fulcrum. The positioning sleeve 16 is fixed on the top of the mounting shell 9, and the outer cylinder 14 of the water cooling sleeve assembly is interference-fitted in the positioning sleeve 16. The outer cylinder 14 is then welded to the positioning sleeve 16. The water cooling pipe 17 is arranged along the outer circle of the plasma generator 13. The cold water inlet pipe 19 at the bottom is passed with cold water, and the hot water after heat exchange is discharged through the water outlet pipe 20 at the top, which has a good cooling effect and ensures that the plasma generator 13 has a good working environment.

[0023] The ignition electrode and plasma generator 13 (plasma igniter) in the present invention are both existing technologies, which can be purchased on the market, and their working principles are also conventional. The working principle of the ignition electrode is to generate sparks through high-voltage arcs to ignite fuel. The plasma generator 13 is an important part of the plasma ignition technology, and its main working principle is: under certain output current conditions, when the cathode moves forward and contacts the anode, the system is in a short-circuit state; when the cathode slowly leaves the anode, an arc is generated, and the arc is pulled out of the nozzle under the action of the coil magnetic field, and the compressed air is ionized into high-temperature plasma under the action of the arc; the plasma forms a local high-temperature fire core with a core temperature of >5000°C and a large gradient in the ignition burner. When the coal powder particles pass through the plasma fire core, the volatile components in the coal powder are precipitated in a very short time, and the coal powder particles burn rapidly.

[0024] 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 hybrid plasma arc furnace, comprising a furnace body and a furnace cover arranged on the top, an electrode hole is opened in the center of the furnace cover, an ignition electrode is inserted in the electrode hole, and the characteristics are: A plurality of plasma combustion devices are arranged on the furnace cover, and the plurality of plasma combustion devices are evenly arranged along the circumference of the furnace cover.

2. A hybrid plasma arc furnace according to claim 1, characterized in that: The furnace cover includes a central disc part and six sector-shaped parts. The central angle of each sector-shaped part is 60°. The six sector-shaped parts are evenly arranged along the outer circle of the disc part. The electrode hole is opened in the center of the disc part. A plasma combustion device is provided on each of the six sector-shaped parts, and two of the sector-shaped parts are also provided with a feed port and a smoke exhaust port.

3. A hybrid plasma arc furnace according to claim 1 or 2, characterized in that: The plasma combustion device includes 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 bricks, a fixing plate is provided at the bottom around the mounting shell, the fixing plate is connected to the furnace cover through mounting bolts, a water-cooling sleeve assembly is provided on the top of the mounting shell, and combustion-supporting holes that are transparent from top to bottom are correspondingly opened on the mounting shell, the refractory bricks 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.

4. A hybrid plasma arc furnace according to claim 3, characterized in that: The water-cooling sleeve assembly includes an outer cylinder, a heat insulation plate fitted with the top surface of the mounting shell 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 of the mounting shell, the lower end of the outer cylinder is interference fitted in the positioning sleeve, a spiral water-cooling pipe is provided on the inner circle of the outer cylinder along the circumferential direction, 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.

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