Plasma melting furnace and solid waste treatment method

Abstract

The invention relates to the technical field of solid waste treatment melting furnaces, and particularly discloses a plasma melting furnace and a solid waste treatment method.The melting furnace comprises a furnace body and a furnace cover, the interior of the furnace body is divided into two melting pools through a partition wall, the lower end of the partition wall is provided with a melting pool connector, and the portion, located above the partition wall, of the furnace body is provided with a feeding port; the bottoms of the two molten pools are each provided with a metal discharge port and a bottom electrode, an electrode is arranged on the portion, over the two molten pools, of the furnace cover, a flowing channel is formed in the upper end of the furnace body, the two ends of the flowing channel communicate with the upper ends of the two molten pools, and a melt discharge port is formed in the bottom of the flowing channel; electric arc plasma and slag ohm integrated heating are organically combined together, the characteristics of high temperature and Joule heat of plasma are fully utilized, the temperature distribution of melt in a molten pool can be uniform, heat can be efficiently utilized, and the energy consumption is reduced. And the problems of difficult deslagging, low energy utilization rate and the like caused by temperature difference are solved.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste treatment melting furnaces, and specifically discloses a plasma melting furnace and a solid waste treatment method. Background Art

[0002] Plasma melting furnace is a core equipment for melting industrial solid waste. At present, the plasma melting furnace used for solid waste treatment in the industry is more based on the design of electric arc furnace.

[0003] For example, the invention patent with application number 200910184971.5 discloses a device and method for treating solid waste with thermal plasma, which includes a plasma melting pyrolysis furnace, a thermal plasma generating device, a working gas preparation and supply device, a feeding device, a slag discharge and a molten metal discharge device, an exhaust gas purification system and a corresponding measurement and control system; the device can completely destroy the toxic and harmful organic components in various solid wastes through the plasma melting pyrolysis furnace, and basically convert the waste into useful gas, stable, non-leaching toxic glassy slag and recyclable metal components, effectively realizing the effective treatment of industrial solid waste. However, this traditional plasma melting pyrolysis furnace still has some shortcomings: first, for solid waste mainly composed of non-metals, since non-molten waste slag is not conductive, when using this melting furnace to melt non-metallic waste slag, there will be great problems when encountering emergencies and needing to restart the furnace; second, even if the melting furnace adopts a circular arc furnace structure, the temperature field inside it will be unevenly distributed, and because the temperature at the slag discharge port is too low, the viscosity of the melt will be high and the fluidity will be poor, which will make slag discharge difficult, and at the same time, its scale of solid waste treatment is limited. Based on this, the present application proposes a plasma melting furnace for treating solid waste slag mainly composed of non-metals, and effectively solves the above-mentioned problems and shortcomings of traditional plasma melting pyrolysis furnaces. Summary of the invention

[0004] The purpose of the present invention is to provide a plasma melting furnace and a solid waste treatment method to solve the problems of difficulty in starting the furnace, large temperature field difference, difficulty in slag discharge, and insufficient treatment scale when traditional or existing plasma melting furnaces are used to treat non-metallic solid waste slag.

[0005] The present invention is achieved through the following technical solutions: A plasma melting furnace comprises a furnace body and a furnace cover, wherein the interior of the furnace body is divided into two molten pools by a partition wall, a molten pool connecting channel for connecting the two molten pools is arranged at the lower end of the partition wall, a feed port is arranged at the furnace body above the partition wall, a metal discharge port and a bottom electrode are arranged at the bottom of the two molten pools, and a switch is connected between the two bottom electrodes via a wire, and an electrode or an arc plasma torch for generating arc plasma is arranged on the furnace cover directly above the two molten pools; A flow channel is provided at the upper end of the furnace body, and both ends of the flow channel are connected to the upper ends of two molten pools. A molten material discharge port is provided at the bottom of the flow channel, and a plug is provided in the molten material discharge port.

[0006] As a further configuration of the above scheme, a blast port connected to the molten pool is provided on the side of the furnace body, and a fume exhaust port is provided on the furnace cover.

[0007] As a further configuration of the above scheme, the feed port is centrally located just above the partition wall, and a guide block for evenly dividing the material fed into the feed port is provided on the top of the partition wall.

[0008] As a further configuration of the above scheme, a baffle is provided at the position where the flow channel is connected to the molten pool, the upper end of the baffle is connected to the furnace cover, and the lower end is at a certain distance from the bottom wall of the flow channel.

[0009] As a further configuration of the above solution, the flow channel is in the shape of an elongated strip and is separated on both sides by a fire-resistant partition wall in the middle, and the molten material discharge port is arranged at a turning position of the flow channel.

[0010] As a further configuration of the above solution, the turning position of the flow channel is configured to be U-shaped or semicircular, and the melt outlet is configured to be in the middle of the turning position of the flow channel.

[0011] As a further configuration of the above solution, the peripheries of the two electrodes or arc plasma torches for generating arc plasma are both provided with cooling water jackets.

[0012] The present invention also discloses a solid waste treatment method using the plasma melting furnace, comprising the following steps: (1) The bottom of the two molten pools is covered with conductive material, and the switch is closed so that the two bottom electrode circuits are connected to form a loop; (2) Push the two electrodes or arc plasma torches downward until they come into contact with the conductive material, then turn on the power of the electrodes or arc plasma torches and slowly lift them upward to form a plasma arc to heat the conductive material to melt it into a molten liquid, then disconnect the bottom electrode circuit and conduct the current of the molten liquid in the two molten pools through the molten pool connecting channel; (3) The solid waste to be treated is evenly put into two melting pools so that it is melted by the heat energy generated by the plasma arc to form a molten material. The molten material rises and enters the flow channel. When the molten material completely covers the flow channel, it contacts the two electrodes or arc plasma torches to form a loop. At this time, the solid waste put in is firstly melted rapidly by the plasma sub-arc, and then continuously heated and kept warm by the Joule heat in the loop. After the molten material in the flow channel reaches a certain amount, the molten material discharge port is opened to discharge the molten material. (4) As the running time goes by, the metal layer in the molten pool will rise. At this time, the electrode or arc plasma torch is lowered to contact the bottom of the molten pool, and then the electrode or arc plasma torch is slowly lifted upward to observe the voltage change of the electrode or arc plasma torch. The depth of the metal layer is calculated based on the lifting speed. After the depth of the metal layer reaches the preset value, the metal discharge port is opened to discharge the metal layer.

[0013] As a further configuration of the above scheme, it also includes immediately stopping the feeding of solid waste when encountering an emergency and determining that it cannot be resolved in a short time, and immediately opening the metal discharge port to quickly discharge all the molten materials in the molten pool.

[0014] As a further configuration of the above scheme, when the molten pool in step (3) is melting the solid waste, air is continuously introduced into the molten pool to achieve stirring and organic matter oxidation.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The plasma melting furnace disclosed in the present invention organically combines arc plasma and ohmic integrated heating of slag, making full use of the high temperature and Joule heat characteristics of plasma. The existing plasma treatment of non-metallic solid waste mostly uses Joule heat, while in the present invention, the solid waste is first subjected to high-temperature melting treatment of the plasma arc after entering, and then subjected to the action of Joule heat after entering the molten pool, thereby maintaining a uniform temperature, thereby more effectively utilizing energy and reducing energy consumption.

[0016] The molten pool and flow channel in the furnace body of the present invention adopt an up and down stepped design, which can effectively construct an artificial slag ohmic integrated heating channel, thereby ensuring uniform temperature distribution of the molten material inside the molten pool and efficient use of heat, avoiding temperature differences in the molten material inside the molten pool, thereby leading to problems such as difficulty in slag discharge and low energy utilization.

[0017] When the molten pool in the present invention processes non-metallic solid waste, air is continuously blown into it, which not only enables the non-metallic solid waste to be effectively incinerated in the molten pool, releasing energy to reduce the energy required for its own processing, but also the blown air can form agitation inside the molten pool, making the temperature inside the molten pool more uniform.

[0018] The plasma melting furnace and the treatment method disclosed in the present invention, through the design of the bottom electrodes at the lower ends of the two melting pools, can quickly start the melting furnace to form a melt inside it when melting non-metallic solid waste, and then continuously treat the added solid waste, which greatly improves the start-up speed of the entire furnace. At the same time, its internal volume is larger than that of a traditional electric arc furnace, and the processing capacity is effectively increased, which effectively improves its processing speed and processing scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the main internal plane structure of the present invention; Figure 2 It is a schematic diagram of the internal planar structure of the present invention from a side view; Figure 3 It is a schematic diagram of the internal planar structure of the present invention when viewed from above. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Figures 1 to 3 , and describes the application in detail with reference to embodiments. Example 1

[0023] Embodiment 1 discloses a plasma melting furnace for treating non-metallic waste slag melting, comprising a furnace body 1 and a furnace cover 2. The interior of the furnace body 1 is surrounded by refractory materials to form two mirror-symmetrically arranged molten pools 3, and two electrodes 4 or arc plasma torches that can generate arc plasma are arranged on the furnace cover 2 above each molten pool 3. A metal discharge port 301 is arranged at the bottom of each of the two molten pools 3, and a bottom electrode 5 is arranged at the bottom of each of the two molten pools 3, and the two bottom electrodes 5 are connected to a switch 6 through a wire, so that after the switch 6 is closed, the two bottom electrodes 5 can form a circuit.

[0024] A partition wall 7 is provided between the two molten pools 3, through which two molten pools are formed, and a molten pool connecting channel 8 for connecting the two molten pools 3 is provided at the lower end of the partition wall 7. A feed port 9 is provided at the upper end of the side of the furnace body 1, and the feed port 9 is centrally located just above the partition wall 7, and a guide block 10 is provided at the top of the partition wall 7, so that the materials put in from the feed port 9 can be distributed as evenly as possible into the two molten pools 3 under the action of the guide block 10.

[0025] A flow channel 11 for connecting the upper ends of the two molten pools 3 is provided in the furnace body 1 located on the opposite side of the feed port 9, and the cross section of the flow channel 11 is designed in a U shape. In the specific design, the flow channel 11 is in a long strip shape, and the two sides are separated by a refractory partition wall 12 in the middle to form a U shape, and then a melt outlet 111 is opened at the bottom of the rotation position of the flow channel 11, and a plug 13 that can move up and down to block or open the melt outlet 111 is provided in the furnace cover 2 just above the melt outlet 111. In this embodiment 1, the rotation position of the flow channel 11 can be designed to be U-shaped or semicircular, and the melt outlet 111 is set at its middle position.

[0026] In addition, a baffle 14 made of refractory material is provided at the position where the flow channel 11 is connected to the upper end of the molten pool 3. The upper end of the baffle 14 is connected to the furnace cover 2, and the lower end thereof is kept at a certain height from the bottom wall of the flow channel 11. The baffle 14 is designed to intercept the unmelted solid waste on the upper layer of the molten pool 3, and prevent the solid waste from being directly discharged from the molten material discharge port 111 without being processed. At the same time, a flue gas flow hole is opened at the upper end of the baffle 14, so that the flue gas above the molten pool 3 can enter the upper part of the flow channel 11.

[0027] In this embodiment 1, an air blast port 15 connected to the molten pool 3 is also provided on the side of the furnace body 1 below the flow channel 11. The air blast port 15 is approximately located at 1 / 2 of the depth of the molten pool 3. Air is continuously input into the molten pool 3 through the air blast port 15, thereby playing the role of stirring the molten pool and oxidizing a small amount of organic matter. At the same time, a fume exhaust port 16 is also provided on the furnace cover 2, through which the fume generated during the melting process can be directed and discharged, and discharged after being treated by the subsequent fume treatment equipment.

[0028] Finally, the two electrodes 4 for generating arc plasma in this embodiment 1 are provided with cooling water jackets 17 on their peripheries. When the electrodes 4 are in operation for a long time, cooling water is continuously introduced to cool the electrodes 4, thereby avoiding high temperature and high load operation of the electrodes 4 and improving the service life of the electrodes 4. Example 2

[0029] Example 2 discloses a method for treating solid waste using the plasma melting furnace in Example 1.

[0030] In the first step, the bottom of the two molten pools 3 is covered with conductive materials such as steel plates, scrap iron or coke to cover the bottom electrode 5, and then the switch 6 is closed to connect the circuits of the two bottom electrodes 5 to form a loop.

[0031] In the second step, the two electrodes 4 or arc plasma torches that generate arc plasma are pushed downward to make them contact with the conductive material covering the bottom of the molten pool 3, and then the power of the electrodes 4 or arc plasma torches is turned on. Then, the two electrodes 4 or arc plasma torches are slowly lifted upward to form a plasma arc to heat the conductive material at the bottom of the molten pool 3 to melt it and form a molten liquid. Finally, the switch 6 is disconnected to disconnect the circuit of the bottom electrode 5, and the current of the molten liquid in the two molten pools is conducted by relying on the molten pool connecting channel 8.

[0032] In the third step, solid waste is put into the furnace body through the feed port 9, and is evenly distributed into the two molten pools under the action of the guide block 10, and then melted by the heat energy generated by the generated plasma arc, and the generated flue gas is discharged from the furnace body through the flue gas outlet 16 and connected to the subsequent flue gas treatment equipment for treatment, and the melt remains in the molten pool 3. In addition, when the solid waste is treated, air can be continuously introduced into the molten pool 3 through the air blowing port 15, so as to stir the molten material in the molten pool and oxidize a small amount of organic matter.

[0033] In the fourth step, solid waste is continuously put into the two molten pools 3. The liquid level of the molten material will rise and enter the flow channel 11. When the molten material completely covers the flow channel 11, it will contact the two electrodes 4 or the arc plasma torch to form a loop. Then, the solid waste is firstly melted rapidly by the generated plasma sub-arc, and then continuously kept warm and heated by the Joule heat in the loop. After the molten material in the flow channel 11 reaches a certain amount, the plug 13 is lifted to open the molten material discharge port 111, thereby allowing the molten material to flow out of the furnace body.

[0034] Step 5: As the operation time goes by, the metal layer in the molten pool 3 will slowly rise, thereby squeezing the capacity of the molten pool and reducing the processing volume. At this time, the electrode 4 or arc plasma torch is first lowered to make it contact with the bottom of the molten pool 3, and then the electrode 4 or arc plasma torch is slowly lifted upward, and the voltage change of the electrode 4 or arc plasma torch is observed, and the depth of the metal layer is calculated in combination with the lifting speed. When the depth of the metal layer reaches a preset value (such as more than 1 / 2 of the depth of the molten pool), the metal discharge port 301 is opened to discharge the metal layer in the molten pool 3, and when the metal layer is basically emptied, the metal discharge port 301 can be re-blocked.

[0035] In addition, when encountering an emergency and it is determined that it cannot be resolved in a short time, stop feeding immediately, and immediately open the metal discharge port 301 to quickly discharge all the molten materials in the molten pool to prevent affecting the next furnace start-up.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A plasma melting furnace, comprising a furnace body and a furnace cover, characterized in that: The interior of the furnace body is divided into two molten pools by a partition wall, a molten pool connecting channel for connecting the two molten pools is provided at the lower end of the partition wall, a feed port is provided at the furnace body above the partition wall, a metal discharge port and a bottom electrode are provided at the bottom of the two molten pools, and a switch is connected between the two bottom electrodes via a wire, and an electrode or an arc plasma torch for generating arc plasma is provided on the furnace cover directly above the two molten pools; A flow channel is provided at the upper end of the furnace body, and both ends of the flow channel are connected to the upper ends of two molten pools. A molten material discharge port is provided at the bottom of the flow channel, and a plug is provided in the molten material discharge port.

2. The plasma melting furnace according to claim 1, characterized in that: The side of the furnace body is provided with an air blowing port connected with the molten pool, and the furnace cover is provided with a fume exhaust port.

3. The plasma melting furnace according to claim 1, characterized in that: The feed inlet is centrally located just above the partition wall, and a guide block for evenly dividing the material put into the feed inlet is arranged on the top of the partition wall.

4. The plasma melting furnace according to claim 1, characterized in that: A baffle is provided at the position where the flow channel is connected to the molten pool, the upper end of the baffle is connected to the furnace cover, and the lower end is at a certain distance from the bottom wall of the flow channel.

5. The plasma melting furnace according to claim 1, characterized in that: The flow channel is in the shape of an elongated strip and is divided into two sides by a fireproof partition wall in the middle. The molten material discharge port is arranged at the turning position of the flow channel.

6. The plasma melting furnace according to claim 5, characterized in that: The turning position of the flow channel is arranged in a U shape or a semicircle, and the melt outlet is arranged in the middle of the turning position of the flow channel.

7. The plasma melting furnace according to claim 1, characterized in that: The peripheries of the two electrodes or arc plasma torches for generating arc plasma are both provided with cooling water jackets.

8. A solid waste treatment method using the plasma melting furnace according to any one of claims 1 to 7, characterized in that: The steps include: (1) The bottom of the two molten pools is covered with conductive material, and the switch is closed so that the two bottom electrode circuits are connected to form a loop; (2) Push the two electrodes or arc plasma torches downward until they come into contact with the conductive material, then turn on the power of the electrodes or arc plasma torches and slowly lift them upward to form a plasma arc to heat the conductive material to melt it into a molten liquid, then disconnect the bottom electrode circuit and conduct the current of the molten liquid in the two molten pools through the molten pool connecting channel; (3) The solid waste to be treated is evenly put into two melting pools so that it is melted by the heat energy generated by the plasma arc to form a molten material. The molten material rises and enters the flow channel. When the molten material completely covers the flow channel, it contacts the two electrodes or arc plasma torches to form a loop. At this time, the solid waste put in is firstly melted rapidly by the plasma sub-arc, and then continuously heated and kept warm by the Joule heat in the loop. After the molten material in the flow channel reaches a certain amount, the molten material discharge port is opened to discharge the molten material. (4) As the running time goes by, the metal layer in the molten pool will rise. At this time, the electrode or arc plasma torch is lowered to contact the bottom of the molten pool, and then the electrode or arc plasma torch is slowly lifted upward to observe the voltage change of the electrode or arc plasma torch. The depth of the metal layer is calculated based on the lifting speed. After the depth of the metal layer reaches the preset value, the metal discharge port is opened to discharge the metal layer.

9. The solid waste treatment method according to claim 8, characterized in that: It also includes immediately stopping the feeding of solid waste when encountering an emergency and determining that it cannot be resolved in a short time, and immediately opening the metal discharge port to quickly discharge all the molten materials in the molten pool.

10. The solid waste treatment method according to claim 8, characterized in that: When the molten pool in step (3) is melting the solid waste, air is continuously introduced into the molten pool to achieve stirring and organic matter oxidation.

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