A kind of waste tyre regeneration carbon black plasma grading purification treatment system

Abstract

The application relates to a waste tire regenerated carbon black plasma grading and purifying treatment system, belonging to the field of carbon black thermal cracking, which comprises a powder feeding system, a plasma reactor, a cooling device, a gas-solid separation device, a cooling water system and a gas supply system. A plurality of groups of plasma torch combinations are arranged on the plasma reactor, each group of plasma combinations is arranged in a polygonal tangential circle on a certain transverse section in the reactor by a plurality of tubular direct current arc plasma torches, the powder feeding device is connected with the plasma torch, powder to be treated is transported into the plasma torch, and the outlet end of the plasma reactor, the cooling device and the gas-solid separation device are sequentially connected. The cooling water system cools the plasma reactor, the plasma torch, the cooling device and the gas-solid separation device and is recycled. The gas supply system provides working gas. The waste tire regenerated carbon black is graded and purified according to different particle size grades, and high-purity carbon black products with different particle sizes are obtained.

Description

Technical Field

[0001] This application belongs to the field of carbon black pyrolysis technology, and specifically relates to a plasma-based graded purification system for recycled carbon black from waste tires. Background Technology

[0002] With rapid economic development, the widespread use of automobiles has led to a surge in tire consumption. Currently, my country is the world's largest producer of waste tires. Improper disposal of waste tires can cause significant harm to the natural environment. Large-scale accumulation of waste tires not only wastes resources and breeds insects, but also easily causes fires that are difficult to extinguish. Because waste rubber is a thermosetting polymer with high toughness and elasticity, it is difficult to degrade, and recycling processes are extremely complex and costly. Current tire recycling methods mainly include rubber powder production, incineration, and pyrolysis. Rubber powder production is costly, and its demand and growth rate cannot keep pace with the growth rate of waste tire generation. Incineration can recover the thermal energy of waste tires, but it cannot recover valuable chemical raw materials. Pyrolysis of waste tires, however, offers a high-value-added and environmentally friendly recycling route.

[0003] Because waste tires have a high carbon content, they can be used to prepare activated carbon and carbon black products. The usual method of preparing carbon black products from waste tires is to pyrolyze the waste tires and use the residue from the pyrolysis process as carbon black products. However, such carbon black products have a high degree of environmental pollution, high ash content, poor dispersibility, poor compatibility with rubber, low selling price, poor economic benefits, and weak market competitiveness. Summary of the Invention

[0004] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a plasma classification and purification system for recycled carbon black from waste tires, which realizes the classification and purification of recycled carbon black from waste tires according to different particle size grades to obtain high-purity carbon black products with different particle sizes.

[0005] This invention addresses the key purification process in the deep resource recovery of pyrolysis carbon black from waste tires. It focuses on improving the shortcomings of existing pyrolysis carbon black purification processes, solving problems such as incomplete purification and severe environmental pollution, and achieving graded purification of recycled carbon black to obtain carbon black products with different purities and particle sizes.

[0006] The technical solution provided in this application is as follows:

[0007] A plasma-based graded purification system for recycled carbon black from waste tires includes a plasma reactor. The plasma reactor comprises a cylindrical cylinder, a frustum-shaped cylinder, and a first powder collection tank. The large-diameter end of the frustum-shaped cylinder is connected to the bottom of the cylindrical cylinder, and the first powder collection tank is connected to the small-diameter end of the frustum-shaped cylinder. Multiple layers of tangentially shaped plasma torch assemblies are installed on the cylindrical cylinder from top to bottom. Each layer of the tangentially shaped plasma torch assembly includes multiple plasma torches. The outlet end of each plasma torch extends into the cylindrical cylinder, and the inlet end of the plasma torch is located outside the cylindrical cylinder. The polygonal tangential plasma torch assembly includes multiple plasma torches located at the same height along the axial direction of the cylindrical tube. The plasma torches are used to heat the gas-solid mixture to obtain a high-temperature gas-solid mixture. The solid in the gas-solid mixture is carbon black particles. The particle size of the carbon black particles ejected from different layers of the polygonal tangential plasma torch assembly gradually decreases from top to bottom. The plasma reactor also includes a top cover, which is installed at the upper end of the cylindrical tube. The top cover is equipped with a cooling structure for enriching the pyrolysis products of the carbon black particles. The side wall of the cylindrical tube near the frustum section is provided with a gas-solid mixture outlet.

[0008] Each layer of the polygonal tangential plasma torch assembly includes multiple plasma torches whose gas-solid mixture ejection direction has a common tangential circle, the diameter of which is 50%-70% of the inner diameter of the cylindrical tube.

[0009] From top to bottom, the diameter of the tangent circle in the ejection direction of the gas-solid mixture of the multiple plasma torches in the polygonal tangent plasma torch assembly increases sequentially.

[0010] Each layer of the polygonal tangent plasma torch assembly includes multiple plasma torches that are evenly distributed around the circumference of the cylindrical tube. The number of plasma torches included in each layer of the polygonal tangent plasma torch assembly is 3, 3n, 4, or 4n, where n is an integer.

[0011] The cooling structure includes multiple water-cooled fins disposed on the inner end of the top cover facing the cylindrical tube. The multiple water-cooled fins are evenly distributed around the axis of the top cover and along the direction from the top cover to the cylindrical tube. The normal of the fin surface gradually approaches the axis of the cylindrical tube, and the angle between the normal of the fin surface and the direction of the cylindrical tube axis is π / 6-π / 3. The lower end of the fin is located on the side of the uppermost polygonal tangent plasma torch assembly facing the top cover.

[0012] Each layer of the polygonal tangent plasma torch assembly includes a plasma torch connected to a powder feeding system for conveying a gas-solid mixture to the inlet end of the plasma torch.

[0013] The powder feeding system includes a silo, a powder tank, and a dispersing mechanism. The silo contains carbon black particles that have been coarsely screened according to their particle size. The bottom of the silo is connected to the powder tank, which is used to send the carbon black particles to the dispersing mechanism. The dispersing mechanism disperses the carbon black particles and sends them to the inlet of the plasma torch via air.

[0014] The outlet of the gas-solid mixture is connected to a cooling device, which is a cylindrical water-cooled structure used to cool the gas-solid mixture flowing out of the outlet. The cooling device is gradually tilted upward along the direction away from the plasma reactor. The axial direction of the cooling device forms an angle of π / 4-π / 3 with the axial direction of the cylindrical tube of the plasma reactor.

[0015] The end of the cooling device furthest from the plasma reactor is connected to a gas-solid separation device, which is used to separate the gas-solid mixture.

[0016] The gas-solid separation device is connected to a vacuum system, which includes a vacuum pump and a circulating water tank. The circulating water tank is connected to a vacuum pipeline, and the other end of the vacuum pipeline is connected to the gas-solid separation device. The vacuum pump is connected to the vacuum pipeline, and the dust in the gas-solid separation device is drawn into the circulating water tank for washing before being discharged.

[0017] In summary, this application includes at least the following beneficial technical effects:

[0018] This invention discloses a plasma-based graded purification system for recycled carbon black from waste tires. This system can quickly and efficiently achieve graded purification of recycled carbon black. By performing layered heat treatment on recycled carbon black particles of different sizes and then collecting them step by step, it can not only grade and purify recycled carbon black from waste tires according to different particle sizes to obtain high-purity carbon black products of different particle sizes, but also make good use of other particle purification processes or high-temperature heat treatment processes. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a plasma-based graded purification system for recycled carbon black from waste tires, as described in this invention.

[0020] Figure 2 This is a schematic diagram of a powder feeding system according to the present invention;

[0021] Figure 3 This is a schematic diagram of a set of polygonal tangent plasma torch assemblies according to the present invention;

[0022] Figure 4 This is a schematic diagram of the top cover of the plasma reactor described in this invention.

[0023] Explanation of reference numerals in the attached diagrams: 1. Powder feeding system; 2. Plasma reactor; 3. Cooling device; 4. Gas-solid separation device; 5. Plasma torch;

[0024] 11. Material hopper; 12. Powder hopper; 13. Powder tray; 14. Electric motor; 15. Electric switch mechanism;

[0025] 21. Top cover; 22. Ribs. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0027] like Figure 1 As shown in the embodiment of this application, a plasma-based graded purification system for recycled carbon black from waste tires is disclosed. It mainly consists of a powder feeding system 1, a plasma reactor 2, a cooling device 3, a gas-solid separation device 4, a particle collection system, a vacuum system, a cooling water system, and a gas supply system. Several plasma torches 5 are arranged on the plasma reactor 2. The powder feeding system 1 is connected to the plasma torches 5 and directly feeds the powder to be processed into the nozzles of the plasma torches. The outlet end of the plasma reactor 2 is connected to the front end of the cooling device 3, and the rear end of the cooling device 3 is connected to the inlet end of the gas-solid separation device 4. The cooling water system cools the plasma reactor 2, plasma torches 5, cooling device 3, and gas-solid separation device 4, and achieves recycling. The gas supply system provides working gas to the powder feeding system 1 and the plasma torches 5.

[0028] like Figure 2 As shown, the powder feeding system 1 is a system device consisting of a hopper 11, a powder tank 12, a powder rotary conveying mechanism 13, a motor 14, an electric switch mechanism 15, as well as pipes, valves, and an auxiliary support platform. The hopper 11 is located at the top of the system, and its bottom outlet is connected to the upper port of the powder tank 12 via a pipe. The electric switch mechanism 15 is located on the pipe between the hopper 11 and the powder tank 12. The lower port of the powder tank 12 is connected to the powder rotary conveying mechanism 13. The powder rotary conveying mechanism 13 has an air inlet and an air outlet on its exterior. The air inlet is connected to the air supply system, and the air outlet is connected to the plasma torch 5 via a pipe. Inside the powder rotary conveying mechanism 13, there is a disc. The central hole of the disc is connected to the rotating shaft of the motor 14, and an annular powder trough is provided on the upper surface of the disc. The inner cavity of the powder tank 12 and the inner cavity of the powder rotary conveying mechanism 13 are connected by a pipe to balance the air pressure inside the powder tank 12 and the powder rotary conveying mechanism 13. The powder rotary conveyor 13 controls the rotation speed of the powder tray by a motor 14 located at its lower end.

[0029] like Figure 3 As shown, the plasma reactor 2 is a cylindrical body composed of two parts: an upper cylindrical tube and a lower converging frustum-shaped cylinder. The large-diameter end of the frustum-shaped cylinder is connected to the bottom of the cylindrical tube, and the interiors of the cylindrical tube and the frustum-shaped cylinder are connected. The bottom of the frustum-shaped cylinder is connected to a first powder collection tank. On a certain cross-section of the upper cylindrical tube of the plasma reactor 2, there are 3 or 3n plasma torches 5, where n is an integer, or 4 or 4n plasma torches 5, where n is an integer. One end of the plasma torch 5 extends into the plasma reactor 2, and the other end is located outside the plasma reactor 2. The powder feeding system 1 transports the gas-solid mixture (a mixture of regenerated carbon black particles and gas) to the arc chamber between the front and rear electrodes of the plasma torch 5. The high-temperature plasma generated by the discharge between the electrodes of the plasma torch 5 heats the gas-solid mixture under the action of the high-speed rotating airflow inside. The regenerated carbon black particles are then fed into the plasma reactor 2 along with the plasma jet through the nozzle. They can then undergo a pyrolysis reaction in the high-temperature plasma zone, so that the impurities inside the carbon black are pyrolyzed and gasified, and the carbon black itself is pyrolyzed to form carbon black products of various particle sizes. The jet from the nozzle of the plasma torch is arranged tangentially around an imaginary circle on a cross-section of the upper cylindrical section of the plasma reactor 2. The diameter of the imaginary circle is 50%-70% of the inner diameter of the upper cylindrical section of the plasma reactor 2. Several plasma torches 5 at the same cross-section form a polygonal tangential plasma torch assembly. This assembly is arranged in multiple layers at different heights on the upper cylindrical section of the plasma reactor 2, specifically at least two layers; in this embodiment, four layers are arranged. Furthermore, from top to bottom, the diameter of the imaginary circle tangentially arranged around the imaginary circle on the cross-section of the corresponding polygonal tangential plasma torch assembly increases sequentially. Each layer of the polygonal tangential plasma torch assembly ejects a gas-solid mixture and forms a high-temperature zone at a corresponding position within the plasma reactor 2, which heats the carbon black particles passing through that position.

[0030] Each layer of the polygonal tangential plasma torch assembly is connected to the same powder feeding system 1. Polygonal tangential plasma torch assemblies of different layers are connected to different powder feeding systems 1. The recycled carbon black particles conveyed by the powder feeding system 1 connected to the upper layer of the polygonal tangential plasma torch assembly are larger than the recycled carbon black particles conveyed by the powder feeding system 1 of the lower layer.

[0031] The recycled carbon black to be processed is coarsely screened according to different particle sizes to obtain multi-stage carbon black particles with different particle sizes. The multi-stage carbon black particles are respectively put into the corresponding powder feeding system 1, so that the carbon black particles enter the plasma torch from the upper layer to the lower layer of the polygonal tangent plasma torch assembly in order of particle size from large to small, so as to achieve layered heat treatment of different particle sizes.

[0032] like Figure 4As shown, the plasma reactor 2 also includes a top cover 21, which is installed on the upper end of the upper cylindrical tube of the plasma reactor 2. A series of water-cooled fins 22 are arranged on the top cover 21 facing the inside of the reactor. The normal to the surface of the fins 22 is arranged at a certain angle to the axis of the cylindrical tube, with the angle being between π / 6 and π / 3. The lower end of the fins 22 is located in the cylindrical part of the plasma reactor 2, and the end of the fin is 0.5-0.8m away from the uppermost polygonal tangent plasma torch assembly cross-section. The surface of the fins is polished.

[0033] A connection port is provided at the lower part of the cylindrical part of the plasma reactor 2, which is connected to the cooling device 3. The cooling device 3 is a cylindrical water-cooled structure, which contains a series of water-cooled pipes and airflow channels. The water flow direction and the airflow direction are arranged parallel to each other along the axis of the cylindrical water-cooled structure and flow in opposite directions. The axial direction of the cooling device 3 is connected to the axial direction of the cylindrical part of the plasma reactor 2 at an angle of π / 4-π / 3.

[0034] The gas-solid separation device 4 consists of four parts, from top to bottom: a gas-solid rotary separation section, a gas-solid suspension section, a contraction section, and a particle collection tank. A tangential gas channel is provided on the gas-solid rotary separation section to guide the upstream gas-solid two-phase flow into the gas-solid rotary separation section of the gas-solid separation device 4 for gas-solid separation.

[0035] In this patent, particle collection is accomplished by a combination of multiple different devices, which are capable of collecting carbon black of different purities and particle sizes. The different devices are a high-purity nanoscale carbon black collecting device composed of a series of water-cooled fins on the top cover of the plasma reactor 2, a general-purity large particle collecting device at the bottom of the converging frustum-shaped cylinder of the plasma reactor 2, and a medium-purity medium-particle-size carbon black collecting device at the bottom of the gas-solid separation device 4.

[0036] The vacuum system includes a water ring vacuum pump and a circulating water tank. The circulating water tank is connected to a vacuum pipeline, and the other end of the vacuum pipeline is connected to a gas-solid separation device 4. The vacuum pump is connected to the vacuum pipeline, and the dust generated by the entire system is discharged in a dust-free manner after being washed with water.

[0037] The implementation principle of this application is as follows: The recycled carbon black to be treated is artificially sieved to form several different particle size grades of powder to be treated. The powders of different grades are fed into the plasma torch assembly of different levels on the plasma reactor 2 through the corresponding powder feeding system. Through this design, the carbon black particles of different sizes are subjected to layered heat treatment after entering the plasma reactor 2. Based on the polygonal tangential arrangement of each layer of plasma torch 5 assembly, the gas-solid mixture sprayed at each level forms a rotating airflow, and the rotating airflow flows downward as a whole. Since the particle size of the original carbon black particles to be treated sprayed from the upper layer is larger than that of the carbon black particles sprayed from the lower layer, the larger carbon black particles pass through more high-temperature zones and have a longer pyrolysis and pyrolysis time as they flow downward until they enter the cooling device 3. As the particle size decreases, the carbon black particles pass through relatively fewer high-temperature zones as they flow downward until they enter the cooling device 3, thus ensuring that the larger carbon black particles can be fully pyrolyzed and pyrolyzed, while the smaller original carbon black particles are ensured to be fully pyrolyzed and pyrolyzed without passing through too long a high-temperature zone and thus being overtreated. After plasma treatment, carbon black particles are converted into gaseous carbon black and solid pyrolysis carbon black of different sizes. The gaseous carbon black is enriched on the upper fins of the reactor and cooled to form nano-carbon black. When the gas-solid mixture in the plasma reactor 2 flows to the inlet of the cooling device 3, the larger particles of pyrolysis carbon black fall into the first powder collection tank, while the remaining carbon black flows further to the subsequent devices with the airflow and enters the cooling device 3. After the cooling device 3 cools the incoming gas-solid mixture, the mixture enters the gas-solid separation device 4. Carbon black particles that meet the screening size of the gas-solid separation device 4 enter the particle collection tank at its bottom, while carbon black particles and dust of other sizes enter the circulating water tank through the vacuum pipeline.

[0038] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0039] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

Claims

1. A plasma-based graded purification system for recycled carbon black from waste tires, characterized in that: The system includes a plasma reactor (2), which comprises a top cover (21), a cylindrical tube, a frustum-shaped cylinder, and a first powder collection tank. The large-diameter end of the frustum-shaped cylinder is connected to the bottom of the cylindrical tube, and the first powder collection tank is connected to the small-diameter end of the frustum-shaped cylinder. A multi-layered tangentially circular plasma torch assembly is installed on the cylindrical tube, arranged sequentially from top to bottom. Each tangentially circular plasma torch assembly includes multiple plasma torches (5). The outlet end of each plasma torch (5) extends into the cylindrical tube, and the inlet end of the plasma torch (5) is located outside the cylindrical tube. Each tangentially circular plasma torch assembly... The plasma torch assembly includes multiple plasma torches (5) located at the same height along the axis of the cylindrical tube; the plasma torches (5) are used to heat the regenerated carbon black to be treated and to enter the reactor (2) along with the plasma jet for pyrolysis and cracking reaction. The carbon black particles ejected from the polygonal tangential plasma torch assembly at different layers from top to bottom gradually decrease in size; the top cover (21) is installed at the upper end of the cylindrical tube and is provided with a cooling structure for enriching the cracking products of the carbon black particles. A gas-solid mixture outlet is provided on the side wall of the cylindrical tube near the frustum section.

2. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 1, characterized in that: Each layer of the polygonal tangential plasma torch assembly includes multiple plasma torches (5) whose gas-solid mixture ejection direction has a common tangential circle with a diameter of 50%-70% of the inner diameter of the cylindrical tube.

3. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 2, characterized in that: From top to bottom, the diameter of the tangent circle of the gas-solid mixture ejection direction of the multiple plasma torches (5) of the polygonal tangent plasma torch assembly increases sequentially.

4. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 1, characterized in that: Each layer of the polygonal tangent plasma torch assembly includes multiple plasma torches (5) that are evenly distributed around the circumference of the cylindrical tube. The number of plasma torches (5) in each layer of the polygonal tangent plasma torch assembly is 3, 3n, 4 or 4n, where n is an integer.

5. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 1, characterized in that: The cooling structure includes multiple water-cooled fins (22) disposed on the top cover (21) facing the inner end of the cylindrical tube. The multiple water-cooled fins (22) are evenly distributed around the axis of the top cover (21) and along the direction from the top cover to the cylindrical tube. The normal of the surface of the fin (22) gradually approaches the axis of the cylindrical tube. The angle between the normal of the surface of the fin (22) and the axis of the cylindrical tube is π / 6-π / 3. The lower end of the fin (22) is located on the side of the uppermost polygonal tangent plasma torch assembly facing the top cover (21).

6. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 5, characterized in that: Each layer of the multi-angled circular plasma torch assembly includes a plasma torch (5) connected to a powder feeding system (1). The powder feeding system (1) transports the gas-solid mixture to the arc chamber between the front and rear electrodes of the plasma torch (5). The gas-solid mixture is a mixture of regenerated carbon black particles and gas. The high-temperature plasma generated by the discharge between the electrodes of the plasma torch (5) heats the gas-solid mixture under the action of the high-speed rotating airflow inside. The regenerated carbon black particles are then transported into the plasma reactor (2) along with the plasma jet through the nozzle. They can then undergo pyrolysis and pyrolysis reactions in the high-temperature plasma zone, so that the impurities inside the carbon black are pyrolyzed and gasified, and the carbon black body is pyrolyzed to form carbon black products of various particle sizes. Each layer of the multi-angled circular plasma torch assembly is connected to the same powder feeding system (1). Different layers of the multi-angled circular plasma torch assembly are connected to different powder feeding systems (1). The regenerated carbon black particles transported by the powder feeding system (1) connected to the upper layer of the multi-angled circular plasma torch assembly are larger than the regenerated carbon black particles transported by the powder feeding system (1) connected to the lower layer.

7. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 6, characterized in that: The powder feeding system (1) includes a hopper (11), a powder tank (12) and a dispersing mechanism. The hopper (11) contains carbon black particles after coarse screening according to particle size. The bottom of the hopper (11) is connected to the powder tank (12). The powder tank (12) is used to send the carbon black particles to the dispersing mechanism. The dispersing mechanism disperses the carbon black particles and sends them to the inlet end of the plasma torch (5) by air.

8. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 1, characterized in that: The outlet of the gas-solid mixture is connected to a cooling device (3), which is a cylindrical water-cooled structure used to cool the gas-solid mixture flowing out of the outlet. The cooling device (3) gradually tilts upward along the direction away from the plasma reactor (2). The axial direction of the cooling device (3) forms an angle of π / 4-π / 3 with the axial direction of the cylindrical part of the plasma reactor (2).

9. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 8, characterized in that: The end of the cooling device (3) away from the plasma reactor (2) is connected to the gas-solid separation device (4), which is used to separate the gas-solid mixture.

10. The plasma-based graded purification system for recycled carbon black from waste tires according to claim 9, characterized in that: The gas-solid separation device (4) is connected to a vacuum system, which includes a vacuum pump and a circulating water tank. The circulating water tank is connected to a vacuum pipe, and the other end of the vacuum pipe is connected to the gas-solid separation device (4). The vacuum pump is connected to the vacuum pipe, and the dust in the gas-solid separation device (4) is drawn into the circulating water tank for washing and then discharged.

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