A waste plastic grading carbonization device and a waste plastic treatment method

Abstract

This invention relates to the field of waste plastic treatment technology, specifically a waste plastic grading and carbonization device and a waste plastic treatment method. The waste plastic grading and carbonization device includes a feeding hopper, a crushing device, a grinding device, a screening device, a catalyst adaptive proportioning device, a first screw conveyor, a primary carbonization chamber, a secondary carbonization chamber, an activation chamber, a second screw conveyor, a solid product collection device, a liquefaction device, a liquefied product collection device, a cooling water circulation device, a third screw conveyor, a return hopper, and a tail gas treatment device. This invention, through the synergistic innovation of "grading carbonization" and "catalyst adaptive proportioning device," solves the problems of incomplete and uneven carbonization of waste plastics and the incomplete utilization of gaseous products during the pyrolysis process, providing an industrially feasible path for the chemical recycling of waste plastics. The overall structure of this invention is rationally designed, has high processing efficiency, and achieves continuous, complete, and efficient pyrolysis and high-value conversion of waste plastics.

Description

Technical Field

[0001] This invention belongs to the field of waste plastic treatment technology, specifically relating to a waste plastic grading and carbonization device and a waste plastic treatment method. Background Technology

[0002] Plastics are widely used in daily life and industry, including machinery manufacturing, packaging, and coatings. They are a major component of municipal solid waste, characterized by large storage capacity and wide applications. Currently, the main methods for treating waste plastics are landfill, incineration, and physical recycling. Landfill occupies a large amount of land and may pollute soil and groundwater. Incineration, while recovering some energy, wastes inherent hydrocarbon resources and inevitably produces secondary pollutants. Physical recycling requires complex sorting processes and has a low recycling rate. Therefore, developing an effective recycling and reuse process and related equipment for waste plastics is of significant practical importance for alleviating environmental pollution and achieving comprehensive and efficient resource utilization.

[0003] Pyrolysis is a process for recycling waste plastics. However, existing waste plastic pyrolysis technologies have significant shortcomings in heat transfer efficiency, product quality, and operational continuity. Furthermore, the reaction process in existing waste plastic pyrolysis technologies is difficult to precisely control, easily leading to localized overheating and pyrolysis producing large amounts of non-condensable gases, or incomplete pyrolysis generating waxy residues. This results in low pyrolysis oil yield, unstable quality, and inefficient utilization of pyrolysis gas. In addition, traditional fixed-bed catalytic systems in existing waste plastic pyrolysis technologies suffer from problems such as catalyst carbon buildup and deactivation, requiring shutdowns for replacement, and poor continuous operation capability. Existing waste plastic pyrolysis processes generally suffer from lengthy processes, low by-product utilization rates, and high energy consumption, hindering their large-scale promotion. Summary of the Invention

[0004] To address the above problems, this invention provides a waste plastic grading and carbonization device and a waste plastic treatment method. Through the synergistic innovation of "grading carbonization" and "catalyst adaptive proportioning device", it solves the problems of incomplete and uneven carbonization of waste plastics, insufficient utilization of gaseous products, high process energy consumption, and large pollutant emissions during the pyrolysis of waste plastics. It provides an industrially feasible path for the effective recycling and resource utilization of waste plastics. The overall structure is reasonably designed and has high processing energy efficiency, realizing continuous, full, and efficient pyrolysis and high-value conversion of waste plastics.

[0005] This invention is specifically achieved through the following technical solution: A waste plastic grading and carbonization device proposed according to this invention includes a feeding hopper, a crushing device, a grinding device, a screening device, a catalyst adaptive proportioning device, a first screw conveyor, a primary carbonization chamber, a secondary carbonization chamber, an activation chamber, a second screw conveyor, a solid product collection device, a liquefaction device, a liquefied product collection device, a cooling water circulation device, a third screw conveyor, a return hopper, and a tail gas treatment device. The feeding hopper, crushing device, and grinding device are arranged sequentially from top to bottom inside the casing. The bottom of the casing is connected to the screening device. The device consists of a catalyst adaptive proportioning device and a first screw conveyor connected from top to bottom. The first screw conveyor is also connected to the first-stage carbonization chamber via a first star feeder. The first-stage carbonization chamber, the second-stage carbonization chamber, the activation chamber, the second screw conveyor, and the solid product collection device are connected from top to bottom. The first-stage carbonization chamber and the second-stage carbonization chamber are also connected to the liquefaction device. The liquefaction device is connected to the liquefied product collection device and the cooling water circulation device. The cooling water circulation device is also connected to the second screw conveyor. The screening device is also connected to the return silo via a third screw conveyor. The exhaust gas treatment device is connected to the second-stage carbonization chamber.

[0006] The aforementioned waste plastic grading and carbonization device includes a screening device comprising a spherical outer shell and a spherical inner shell. The top of the spherical outer shell is connected to the bottom of the machine casing, and a flow guiding chamber is connected to the bottom of the spherical outer shell. The bottom of the flow guiding chamber is inclined downward. The flow guiding chamber is also connected to a third screw discharge machine. A porous screen is provided on the top of the spherical inner shell in the horizontal direction, and the bottom of the spherical inner shell is connected to a catalyst adaptive proportioning device.

[0007] The aforementioned waste plastic grading and carbonization device includes a catalyst adaptive proportioning device comprising a shell, a sliding member inside the shell, the top of the sliding member being a bearing surface, the bearing surface being inclined towards the center to form a funnel shape; the bottom of the sliding member being a horizontally arranged support panel, at least two springs being installed between the bottom of the support panel and the bottom of the shell, the outer wall of the sliding member being perpendicular to the horizontal plane, and the outer wall of the sliding member being slidably connected to the inner wall of the shell; a bearing surface outlet is provided in the middle of the bearing surface, the bottom of the bearing surface outlet being connected to an inner sleeve, the inner sleeve being fitted inside an outer sleeve and slidably connected to the outer sleeve, the bottom of the outer sleeve being connected to a collection bin, and the collection bin being connected to the inlet of the first screw conveyor.

[0008] Furthermore, a catalyst storage tube is vertically inserted through the sliding component, and the bottom of the catalyst storage tube is fixedly connected to the bottom of the shell. Multiple catalyst outlets are provided in the upper part of the side wall of the catalyst storage tube. When there is no material on the bearing surface of the sliding component, the catalyst outlets are blocked in the sliding component. After the bearing surface is subjected to the gravity of the material, the sliding component compresses the spring and slides downward along the inner side wall of the shell. After the sliding component moves down, the catalyst outlets are exposed on the bearing surface. The catalyst is released onto the bearing surface and mixes with the material on the bearing surface. The mixed material enters the collection bin through the bearing surface outlet, inner sleeve, and outer sleeve, and then sequentially enters the first screw conveyor and the first star feeder. The first star feeder then transports the material to the primary carbonization chamber. Each catalyst storage tube is connected to a catalyst loading pipe at the top, and the catalyst loading pipe is connected to the catalyst feeding bin through a catalyst conveying pipe.

[0009] The aforementioned waste plastic grading and carbonization device comprises: a primary carbonization chamber including a primary carbonization chamber shell and multi-stage guide plates II arranged alternately within the primary carbonization chamber shell; a primary electric heating layer and a primary insulation layer arranged sequentially outside the primary carbonization chamber shell; a secondary carbonization chamber including a secondary carbonization chamber shell and multi-stage guide plates III arranged alternately within the secondary carbonization chamber shell; a combustion chamber, a secondary electric heating layer, and a secondary insulation layer arranged sequentially outside the secondary carbonization chamber shell; an igniter located in the lower part of the combustion chamber; an activation chamber including an activation chamber shell; a tertiary electric heating layer and a tertiary insulation layer arranged sequentially outside the activation chamber shell; multi-stage guide plates IV arranged alternately within the activation chamber; a tertiary carbon outlet located at the bottom of the activation chamber, which is connected to the feed inlet of a second screw conveyor, and the discharge outlet of the second screw conveyor is connected to a solid product collection device.

[0010] Furthermore, a non-condensable gas pipeline exhaust port is provided above the igniter, and the non-condensable gas pipeline is connected to the non-condensable gas outlet on the liquefaction device; an air pipeline exhaust port is provided below the igniter, and the air pipeline is connected to the blower; a nitrogen inlet is also provided on the side wall of the secondary carbonization chamber shell, and the nitrogen inlet is connected to the second nitrogen cylinder; a second star-shaped feeder is also connected between the secondary carbonization chamber and the activation chamber.

[0011] The aforementioned waste plastic grading and carbonization device also includes a cooling circulating water jacket on the outer wall of the second screw discharge machine housing. The cooling circulating water jacket has a first cooling water inlet and a first cooling water outlet. Both the first cooling water inlet and the first cooling water outlet are connected to the cooling water circulation device.

[0012] The aforementioned waste plastic grading and carbonization device includes a first pyrolysis gas discharge pipe connected to the side wall of the primary carbonization chamber shell, and a second pyrolysis gas discharge pipe connected to the side wall of the secondary carbonization chamber shell. The first and second pyrolysis gas discharge pipes merge and connect to the pyrolysis gas inlet on the liquefaction device. The liquefaction device includes a condensation chamber, a liquefaction chamber, and a baffle plate. A second cooling water inlet is provided at the lower part of the side wall of the condensation chamber, and a second cooling water outlet is provided at the upper part of the side wall of the condensation chamber. The second cooling water inlet is connected to a cooling water circulation device, and the second cooling water outlet is connected to a high-temperature water storage device. The liquefaction chamber is located inside the condensation chamber, with its top closed and its bottom connected to a liquefaction product collection device. The baffle plate is located at the top of the liquefaction chamber. An arc-shaped gas channel is provided in the baffle plate, and the non-condensable gas outlet communicates with the arc-shaped gas channel.

[0013] Furthermore, the first outlet of the high-temperature water storage unit is connected to the inlet of the spiral coil, which is coiled within the secondary insulation layer of the secondary carbonization chamber. The outlet of the spiral coil is connected to the gas-liquid separator, the gas outlet of the gas-liquid separator is connected to the first inlet of the gas mixing chamber, the second inlet of the gas mixing chamber is connected to the second nitrogen cylinder, and the outlet of the gas mixing chamber is connected to the activation chamber. The liquid outlet of the gas-liquid separator is connected to the high-temperature water storage unit, and the second outlet of the high-temperature water storage unit is connected to the cooling water circulation device.

[0014] This invention also provides a method for treating waste plastics, which uses the waste plastic grading and carbonization device described above, and the specific treatment method includes:

[0015] S1. Waste plastic enters the crushing device from the feed hopper for primary crushing, and then enters the grinding device for further particle size refinement. The ground material falls onto the porous screen of the screening device under gravity. Fine particles pass through the mesh of the porous screen into the inner cavity of the spherical inner shell and fall onto the bearing surface of the catalyst adaptive proportioning device connected to the bottom of the spherical inner shell. Large particles fall along the cavity between the spherical inner shell and the outer shell and enter the guide chamber, and then enter the third screw conveyor. After being output by the third screw conveyor, the large particles enter the return hopper. The large particles in the return hopper are periodically fed into the feed hopper by the operator for further crushing and grinding until the particle size is small enough and finally falls onto the bearing surface of the catalyst adaptive proportioning device.

[0016] S2. After the screened fine-particle material falls onto the bearing surface of the sliding part, a certain gravity is applied to the bearing surface, causing the sliding part to compress the spring and slide downward along the inner wall of the shell. After the sliding part moves down, the catalyst outlet on the catalyst storage tube is exposed on the bearing surface. The catalyst is released onto the bearing surface and mixes with the material on the bearing surface. The mixed material enters the collection bin through the bearing surface outlet, inner sleeve, and outer sleeve, then enters the first screw conveyor, and finally enters the first-stage carbonization chamber.

[0017] S3. Waste plastics and catalysts are fully carbonized in the primary carbonization chamber. The solid products from the primary carbonization chamber enter the secondary carbonization chamber for further carbonization. The solid products from the secondary carbonization chamber enter the activation chamber, where high-quality activated carbon and water gas, mainly composed of CO and H2, are formed. The high-quality activated carbon is discharged into the solid product collection device via the second screw conveyor. The water gas, excess water vapor, and a small amount of nitrogen generated during activation enter the combustion chamber of the secondary carbonization chamber. After combustion, they provide heat to the secondary carbonization chamber and help maintain the carbonization temperature. The exhaust gas generated during combustion enters the tail gas treatment device and is discharged into the atmosphere. The gaseous products generated in the primary and secondary carbonization chambers enter the liquefaction unit via the first pyrolysis gas discharge pipe and the second pyrolysis gas discharge pipe, respectively.

[0018] S4. The condensable gas entering the liquefaction unit is liquefied under the action of cooling water. The liquefied products enter the liquefaction product collection device, while the non-condensable gas is discharged from the non-condensable gas outlet and then enters the combustion chamber, where it is ignited by the igniter to generate heat and help maintain the carbonization temperature of the secondary carbonization chamber. The high-temperature water discharged from the second cooling water outlet of the liquefaction unit enters the high-temperature water storage tank and then enters the spiral coil coiled in the secondary insulation layer of the secondary carbonization chamber. Under the action of high temperature, the temperature of the high-temperature water further rises and vaporizes to form high-temperature water vapor. It enters the gas-liquid separator through the outlet of the spiral coil. The high-temperature water vapor separated by the gas-liquid separator enters the gas mixing chamber and mixes with nitrogen before entering the activation chamber, providing a nitrogen environment and high-temperature water vapor for the activation chamber. The high-temperature water vapor and the secondary carbonization products in the activation chamber undergo a carbon-water vapor activation reaction at high temperature to form high-quality activated carbon and water gas with CO and H2 as the main components. The high-temperature water separated by the gas-liquid separator enters the high-temperature water storage tank for recycling.

[0019] Compared with existing technologies, this invention has significant advantages and beneficial effects. Through the above technical solution, this invention achieves considerable technological advancement and practicality, and has broad application value, possessing at least the following advantages:

[0020] (1) In this invention, waste plastics are crushed and ground to obtain small-particle materials, which are then further screened to return large-particle materials to the feed hopper for further crushing and grinding. The fully crushed and ground materials can be more fully used for subsequent graded carbonization and activation. In the waste plastic graded carbonization device of this invention, the temperature of the first-stage carbonization chamber is slightly lower to perform preliminary carbonization of the materials. The solid products of the first-stage carbonization then enter the second-stage carbonization chamber for full carbonization. The solid products of the second-stage carbonization are pyrolytic carbon. The pyrolytic carbon enters the activation chamber and undergoes a controllable carbon-water vapor activation reaction with high-temperature water vapor. The water vapor reacts with some of the carbon in the pyrolytic carbon, etching a well-developed microporous structure inside the pyrolytic carbon to form high-quality activated carbon. At the same time, water gas with CO and H2 as the main components is generated. The generated water gas is introduced into the combustion chamber of the second-stage carbonization chamber and ignited by an igniter to generate heat, providing temperature support for the second-stage carbonization chamber. In the later stage of the reaction, the heating power of the second-stage electric heating layer can be appropriately reduced to realize the high-value utilization of high-value-added gases in the waste plastic treatment process. On the one hand, energy saving and consumption reduction are achieved, and on the other hand, the harm to the atmosphere is reduced. The solid products generated after activation can be collected and further activated to produce higher-quality activated carbon products for use in waste gas and wastewater treatment. The condensable gas can be condensed and liquefied into liquefied products, the main components of which are a mixture of C5-C20 hydrocarbons, which can be utilized at high value. This invention achieves the high-value utilization of solids, gases, and liquids generated during waste plastic treatment.

[0021] (2) Through ingenious design, this invention reuses the high-temperature cooling water discharged from the liquefaction unit. The high-temperature cooling water, already at a certain temperature, is introduced into a spiral coil coiled within the secondary insulation layer of the secondary carbonization chamber. Upon entering the spiral coil, the high-temperature cooling water absorbs heat from the secondary insulation layer, causing its temperature to rise further and vaporize into high-temperature water vapor. After passing through a gas-liquid separator, the separated high-temperature water vapor mixes with nitrogen and enters the activation chamber. This provides an oxygen-deficient environment and sufficient high-temperature water vapor for the activation reaction of the pyrolytic carbon in the activation chamber, promoting the carbon-water vapor activation reaction. The water gas produced by the activation reaction, with CO and H2 as its main components, is a high-quality fuel that can be directly introduced into the combustion chamber for combustion, becoming one of the fuel sources for the combustion chamber. The temperature of the subsequent secondary carbonization chamber can be maintained by the heat generated from fuel combustion in the combustion chamber, thereby reducing the consumption of electrical energy for electric heating. Therefore, this invention fully utilizes the products and cooling circulating water at each stage, achieving full recycling of resources and greatly reducing energy consumption and pollutant emissions.

[0022] (3) The catalyst adaptive proportioning device designed in this invention can realize the automatic release of the catalyst. The catalyst is mixed with the material and discharged through the funnel-shaped support surface. The mixing ratio of the catalyst and the material can be appropriately adjusted by replacing the springs with different elastic coefficients or using different numbers of springs to achieve the best catalytic effect. By adjusting the height of the catalyst feeding chamber, the catalyst can be automatically fed into the catalyst storage pipe, which improves the convenience of the process.

[0023] (4) This invention, through the synergistic innovation of "staged carbonization" and "catalyst adaptive proportioning device," solves the problems of incomplete and uneven carbonization of waste plastics, insufficient utilization of gaseous products, high energy consumption, large pollutant emissions, and complex process steps in the pyrolysis of waste plastics. It provides an industrially feasible path for the effective recycling and resource utilization of waste plastics. The overall structure of this invention is reasonably designed, has high processing energy efficiency, and realizes continuous, full, and efficient pyrolysis and high-value conversion of waste plastics. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the waste plastic grading and carbonization device of the present invention.

[0025] Figure 2 yes Figure 1 A magnified view of part A in the middle.

[0026] Figure 3 yes Figure 1 and Figure 2 Enlarged view of the catalyst adaptive proportioning device.

[0027] Figure 4 yes Figure 1 A magnified view of part B in the middle.

[0028] Figure 5 This is a schematic diagram of the structure of the primary carbonization chamber, the secondary carbonization chamber, and the activation chamber.

[0029] Figure 6 This is a schematic diagram of the liquefaction unit.

[0030] Figure 7 This is a schematic diagram of the spoiler structure.

[0031] In the diagram: 1-Feed hopper; 2-Crushing device; 3-Grinding device; 4-Screwing device; 5-Catalyst adaptive proportioning device; 6-First screw conveyor; 7-First-stage carbonization chamber; 8-Second-stage carbonization chamber; 9-Activation chamber; 10-Second screw conveyor; 11-Solid product collection device; 12-Liquefaction device; 13-Liquefaction product collection device; 14-Cooling water circulation device; 15-Third screw conveyor; 16-Return hopper ; 17-Exhaust gas treatment device; 18-Machine casing; 19-Collection bin; 20-Single valve; 21-First star feeder; 22-Thermocouple; 23-High temperature water storage tank; 24-Spiral coil; 25-Gas-liquid separator; 26-Gas mixing chamber; 27-Second nitrogen cylinder; 28-Second star feeder; 29-Valve; 30-Water pump; 31-Support frame; 32-Pressure relief valve; 33-Guide plate V; 34-Pressure gauge;

[0032] 2.1 - First drive motor;

[0033] 3.1-Moving grinding disc, 3.2-Stationary grinding disc, 3.3-Guide plate I, 3.4-Gap;

[0034] 4.1-Spherical outer shell, 4.2-Spherical inner shell, 4.3-Flow guiding chamber, 4.4-Porous screen, 4.5-Vibration rod, 4.6-Vibrator;

[0035] 5.1-Shell, 5.2-Sliding component, 5.3-Bearing surface, 5.4-Support panel, 5.5-Spring, 5.6-Slide groove, 5.7-Bearing surface outlet, 5.8-Inner sleeve, 5.9-Catalyst storage pipe, 5.10-Catalyst outlet, 5.11-Catalyst loading pipe, 5.12-Catalyst conveying pipe, 5.13-Connection point A, 5.14-Catalyst feeding bin, 5.15-Guide plate, 5.16-Outer sleeve;

[0036] 6.1 - Ring-shaped component; 6.2 - First nitrogen cylinder;

[0037] 7.1 - Primary char inlet, 7.2 - Baffle plate II, 7.3 - Primary electric heating layer, 7.4 - Primary insulation layer, 7.5 - Primary char outlet, 7.6 - First pyrolysis gas discharge pipe;

[0038] 8.1-Secondary char inlet, 8.2-Baffle plate III, 8.3-Secondary char outlet, 8.4-Combustion chamber, 8.5-Secondary electric heating layer, 8.6-Secondary insulation layer, 8.7-Igniter, 8.8-Secondary pyrolysis gas discharge pipe, 8.9-Exhaust gas discharge pipe, 8.10-Air pipeline, 8.11-Blower, 8.12-Regulating valve, 8.13-Flow meter, 8.14-Nitrogen inlet;

[0039] 9.1-Third-stage carbon inlet, 9.2-Third-stage electric heating layer, 9.3-Third-stage insulation layer, 9.4-Guide plate IV, 9.5-Third-stage carbon outlet, 9.6-Activation chamber exhaust pipe;

[0040] 10.1 - Cooling water jacket; 10.2 - First cooling water inlet; 10.3 - First cooling water outlet;

[0041] 12.1 - Pyrolysis gas inlet, 12.2 - Condensation chamber, 12.3 - Liquefaction chamber, 12.4 - Baffle plate, 12.5 - Second cooling water inlet, 12.6 - Second cooling water outlet, 12.7 - Non-condensable gas outlet, 12.8 - Arc-shaped gas passage, 12.9 - First opening of arc-shaped gas passage, 12.10 - Second opening of arc-shaped gas passage, 12.11 - Non-condensable gas pipeline;

[0042] 23.1 - First outlet of high-temperature water storage tank; 23.2 - Second outlet of high-temperature water storage tank. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The present invention provides a waste plastic treatment method through a waste plastic grading and carbonization device, which includes a feeding hopper 1, a crushing device 2, a grinding device 3, a screening device 4, a catalyst adaptive proportioning device 5, a first screw conveyor 6, a primary carbonization chamber 7, a secondary carbonization chamber 8, an activation chamber 9, a second screw conveyor 10, a solid product collection device 11, a liquefaction device 12, a liquefied product collection device 13, a cooling water circulation device 14, a third screw conveyor 15, a return hopper 16, and a tail gas treatment device 17.

[0045] like Figure 1As shown, the feed hopper 1, crushing device 2, and grinding device 3 are arranged sequentially from top to bottom inside the casing 18. The bottom of the casing 18 is connected to the screening device 4. The screening device 4, catalyst adaptive proportioning device 5, and first screw conveyor 6 are connected sequentially from top to bottom. The first screw conveyor 6 is also connected to the primary carbonization chamber 7 via the first star feeder 21. The primary carbonization chamber 7, secondary carbonization chamber 8, activation chamber 9, second screw conveyor 10, and solid product collection device 11 are connected sequentially from top to bottom. The primary carbonization chamber 7 and secondary carbonization chamber 8 are also connected to the liquefaction device 12. The liquefaction device 12 is connected to the liquefied product collection device 13 and the cooling water circulation device 14. The cooling water circulation device 14 is also connected to the second screw conveyor 10. The screening device 4 is also connected to the return hopper 16 via the third screw conveyor 15.

[0046] like Figure 2 As shown, in one embodiment, the crushing device 2 is equipped with rotating blades, which are connected to a rotating shaft. The rotating shaft is connected to a first drive motor 2.1. The first drive motor 2.1 drives the rotating blades to rotate through the rotating shaft, thereby performing primary crushing on the waste plastic raw materials (hereinafter referred to as "materials") that come in from the feed hopper 1. After primary crushing, the particle size of the waste plastic is approximately 5-10 mm.

[0047] like Figure 2 As shown, in one embodiment, the grinding device 3 includes a toothed moving grinding disc 3.1 and a toothed stationary grinding disc 3.2. A small gap exists between the moving grinding disc 3.1 and the stationary grinding disc 3.2 to allow the ground material to pass through. The central rotating shaft of the moving grinding disc 3.1 is connected to the output shaft of a second drive motor (not shown in the figure). The output shaft of the second drive motor drives the moving grinding disc 3.1 to rotate at high speed. The rotating moving grinding disc 3.1 and the stationary grinding disc 3.2, fixed inside the housing 18, generate relative motion, compressing and shearing the material. Under the action of high-speed compression, shearing, friction, and tearing, the material is rapidly ground and refined. The ground material (waste plastic) falls into the screening device 4 through the small gap between the moving grinding disc 3.1 and the stationary grinding disc 3.2. The particle size of the ground material is approximately 1-5 mm.

[0048] Furthermore, a guide plate I 3.3 is provided above each of the moving grinding disc 3.1 and the stationary grinding disc 3.2. The guide plate I 3.3 is inclined downwards, and a gap 3.4 is provided between the two guide plates I 3.3. The gap 3.4 is located above the gap between the moving grinding disc 3.1 and the stationary grinding disc 3.2, corresponding to the gap position. The material crushed by the crushing device 2 falls onto the two guide plates I 3.3. Under the guiding action of the guide plates I 3.3, it is concentrated from the gap 3.4 and falls into the gap position between the moving grinding disc 3.1 and the stationary grinding disc 3.2. Subsequently, the material is squeezed and ground into smaller particles by the moving grinding disc 3.1 and the stationary grinding disc 3.2 in the gap, and then falls into the screening device 4.

[0049] like Figure 2 As shown, the screening device 4 includes a spherical outer shell 4.1 and a spherical inner shell 4.2. The top of the spherical outer shell 4.1 is connected to the bottom of the housing 18. A flow guide chamber 4.3 is connected to the bottom of the spherical outer shell 4.1, and the bottom of the flow guide chamber 4.3 is inclined downward. The flow guide chamber 4.3 is also connected to the feed inlet of the third screw conveyor 15, and the discharge outlet of the third screw conveyor 15 is connected to the return hopper 16.

[0050] A porous screen 4.4 is horizontally arranged at the top of the spherical inner shell 4.2, and the bottom of the spherical inner shell 4.2 is connected to the catalyst adaptive proportioning device 5. The upper part of the spherical inner shell 4.2 is connected to the vibrator 4.6 via a rigid vibration transmission rod 4.5. Under the vibration of the vibrator 4.6, the material is screened through the porous screen 4.4. The material ground by the grinding device 3 falls onto the porous screen 4.4 under gravity. After screening, fine particles smaller than the aperture of the porous screen 4.4 pass through the mesh of the porous screen 4.4 into the inner cavity of the spherical inner shell 4.2 and fall onto the bearing surface 5.3 of the catalyst adaptive proportioning device 5 connected to the bottom of the spherical inner shell 4.2. Large particles larger than the aperture of the porous screen 4.4 fall along the cavity between the spherical inner shell 4.2 and the spherical outer shell 4.1 and enter the spherical outer shell 4. In the bottom-connected guide chamber 4.3, the bottom of the guide chamber 4.3 is inclined downward, and the end connected to the third spiral discharge machine 15 is lower, so that large-diameter materials enter the third spiral discharge machine 15. After being output by the third spiral discharge machine 15, the large-diameter materials enter the return hopper 16. The large-diameter materials in the return hopper 16 are periodically fed into the feed hopper 1 by the operator for further crushing and grinding until the material particle size is small enough and finally falls onto the bearing surface 5.3 of the catalyst adaptive proportioning device 5.

[0051] Furthermore, after the vibration transmission rod 4.5 passes through the mounting hole of the spherical outer shell 4.1, it is fixedly connected to the upper part of the spherical inner shell 4.2. A vibration isolation pad is also provided between the vibration transmission rod 4.5 and the mounting hole of the spherical outer shell 4.1. The vibration isolation pad can be a rubber ring, which is tightly attached to the outer wall of the vibration transmission rod 4.5 and the inner wall of the mounting hole of the spherical outer shell 4.1.

[0052] In one embodiment, a guide plate V33 may be provided inside the pipe connecting the spherical outer shell 4.1 and the housing 18 to guide the material falling from the grinding device 3 so that it falls onto the porous screen 4.4 as much as possible.

[0053] In one embodiment, the aperture of the porous screen 4.4 is 3 mm, but this description is not intended to limit the invention.

[0054] like Figure 3As shown, the catalyst adaptive proportioning device 5 includes a housing 5.1 with a circular bottom. Inside the housing 5.1 is a sliding member 5.2 with a circular cross-section. The top of the sliding member 5.2 is a bearing surface 5.3, which is inclined towards the center to form a funnel shape. The bottom of the sliding member 5.2 is a horizontally positioned support panel 5.4. At least two springs 5.5 are installed between the bottom of the support panel 5.4 and the bottom of the housing 5.1; the number can be four, six, or eight, with no specific limitation, but ensuring even distribution of the springs 5.5. The outer wall of the sliding member 5.2 is perpendicular to the horizontal plane and fits against the inner wall of the housing 5.1. The inner wall of the housing 5.1 has a longitudinally extending groove 5.6, and the outer wall of the sliding member 5.2 has a longitudinally extending slide rail. Under external force, the sliding member 5.2 compresses the springs 5.5 and slides downwards along the groove 5.6. After the external force disappears, the sliding member 5.2 returns to its original position under the action of the springs 5.5.

[0055] A discharge port 5.7 is provided at the center of the funnel-shaped bearing surface 5.3 of the sliding component 5.2. The bottom of the discharge port 5.7 is connected to the inner sleeve 5.8. The inner sleeve 5.8 is fitted inside the outer sleeve 5.16 and is slidably connected to the outer sleeve 5.16. A limiting mechanism is also provided between the inner sleeve 5.8 and the outer sleeve 5.16 to prevent the inner sleeve 5.8 from completely dislodging from the outer sleeve 5.16, or to ensure that the lengths of the inner sleeve 5.8 and the outer sleeve 5.16 are long enough to keep the inner sleeve 5.8 always fitted inside the outer sleeve 5.16. The bottom of the outer sleeve 5.16 is integrally connected to the collection bin 19, and the bottom of the collection bin 19 is connected to the feed port of the first screw conveyor 6.

[0056] like Figure 3As shown, a catalyst storage tube 5.9 is vertically inserted through the sliding member 5.2, and the sliding member 5.2 can slide up and down relative to the catalyst storage tube 5.9. The number of catalyst storage tubes 5.9 is 2-10, or more than 10, with no specific limit, depending on the actual process. The bottom of the catalyst storage tube 5.9 is fixedly connected to the bottom of the shell 5.1 (e.g., by bolts). Multiple catalyst outlets 5.10 are provided in the upper part of the side wall of the catalyst storage tube 5.9. When there is no material on the bearing surface 5.3 of the sliding member 5.2, the sliding member 5.2 is in its initial position, at which time the catalyst outlets 5.10 are sealed in the sliding member 5.2. After the screened fine-particle material (waste plastic) falls from the spherical inner shell 4.2 onto the bearing surface 5.3 of the sliding member 5.2, a certain gravity is applied to the bearing surface 5.3. Under the action of the material's gravity, the bearing surface 5.3 of the sliding member 5.2 compresses the spring 5.5 and slides downward along the groove 5.6 on the inner wall of the shell 5.1. During the downward sliding of the sliding member 5.2 as a whole, the inner sleeve 5.8 slides downward synchronously along the outer sleeve 5.16, while the catalyst storage tube 5.9 remains stationary. After the sliding member 5.2 moves downward as a whole, the catalyst outlet 5.10 is exposed. On the bearing surface 5.3, the catalyst is automatically released and mixed with the material on the bearing surface 5.3. The mixed material enters the collection bin 19 through the bearing surface outlet 5.7, inner sleeve 5.8, and outer sleeve 5.16. The mixed material in the collection bin 19 enters the first screw conveyor 6 through the single valve 20. After being output by the first screw conveyor 6, the mixed material enters the first star feeder 21 located below the outlet of the first screw conveyor 6. The outlet of the first star feeder 21 is connected to the first carbon inlet 7.1 of the first carbonization chamber 7. Feeding through the first star feeder 21 can prevent gas from escaping from the first carbonization chamber 7 and also prevent air from entering the first carbonization chamber 7.

[0057] Preferably, in order to enable the slider 5.2 to slide down in time under gravity, the slider 5.2 is preferably designed as a hollow structure and made of lightweight material to reduce weight. At the same time, the contact surface between the slider 5.2 and the catalyst storage tube 5.9 should be smooth enough so that the slider 5.2 can slide down in time after being subjected to external force.

[0058] Each catalyst storage tube 5.9 is connected to a catalyst loading tube 5.11 at its top. The number of catalyst loading tubes 5.11 equals the number of catalyst storage tubes 5.9. The catalyst loading tubes 5.11 are connected to the catalyst delivery tubes 5.12 at connection point A5.13. The catalyst delivery tubes 5.12 are also connected to the bottom of the catalyst feeding hopper 5.14. The bottom of the catalyst feeding hopper 5.14 is higher than the position of connection point A5.13, which is higher than the top of the catalyst storage tubes 5.9. When the catalyst in the catalyst storage tube 5.9 decreases, the catalyst in the catalyst feeding hopper 5.14 is released through the catalyst delivery tubes 5.12 into each catalyst loading tube 5.11, and finally transported to the corresponding catalyst storage tube 5.9, completing the automatic catalyst feeding process.

[0059] Furthermore, connecting plates can be installed between each catalyst charging pipe 5.11. The connecting plates form a downward inclined guide plate 5.15. After the screened fine particles fall, they fall onto the bearing surface 5.3 through the guide plate 5.15. This can prevent the central material from falling directly into the discharge port 5.7 of the bearing surface without being mixed with the catalyst.

[0060] Preferably, the connection between the catalyst charging pipe 5.11 and the catalyst delivery pipe 5.12 is an arc transition to facilitate catalyst discharge. In one embodiment, the outlet of the catalyst charging pipe 5.11 extends into the corresponding catalyst storage pipe 5.9.

[0061] In one embodiment, the catalyst in the catalyst feeding bin 5.14 and the catalyst loading pipe 5.11 is one or more of ZSM-5 molecular sieve, calcium oxide, and waste FCC catalyst. The mass ratio of the catalyst to waste plastic is 1-8:100.

[0062] Preferably, an annular component 6.1 is installed in the connecting pipe between the discharge port of the first screw conveyor 6 and the inlet of the first star feeder 21. Multiple nozzles are evenly arranged on the wall of the annular component 6.1. The annular component 6.1 is connected to the first nitrogen cylinder 6.2, and a valve is installed on the connecting pipe between the two. After the annular component 6.1 is connected to the first nitrogen cylinder 6.2, a nitrogen gas flow is blown into the connecting pipe between the discharge port of the first screw conveyor 6 and the inlet of the first star feeder 21. The nitrogen gas flow is tilted downwards, forming an annular funnel-shaped nitrogen curtain. This nitrogen curtain provides an oxygen-deficient atmosphere to the first star feeder 21, preventing air from entering the primary carbonization chamber 7 due to wear and tear on the parts of the first star feeder 21 after prolonged operation.

[0063] The primary carbonization chamber 7, secondary carbonization chamber 8, and activation chamber 9 are connected sequentially from top to bottom. The primary carbonization chamber 7 includes a primary carbonization chamber shell and a multi-stage guide plate II 7.2 disposed within the shell. A primary electric heating layer 7.3 and a primary insulation layer 7.4 are sequentially disposed outside the shell, with the insulation layer 7.4 located on the outermost side. The insulation layer 7.4 can be made of ceramic fiber board. A primary carbon inlet 7.1 is located on the upper side wall of the primary carbonization chamber shell, and a primary carbon outlet 7.5 is located at the bottom of the shell. The primary carbon outlet 7.5 is connected to the secondary carbon inlet 8.1 at the top of the secondary carbonization chamber 8. The carbonization temperature of the primary carbonization chamber 7 is maintained at 200~300℃ by heating through the primary electric heating layer 7.3.

[0064] The multi-stage guide plates II 7.2 are arranged in an alternating manner. One end of each guide plate II 7.2 is fixed to the inner wall of the primary carbonization chamber shell, defined as the fixed end, while the other end is suspended, defined as the suspended end. The suspended end of the guide plate II 7.2 is the discharge end. The suspended end of the upper-level guide plate II 7.2 is close to the fixed end of the lower-level guide plate II 7.2, and the suspended end of the upper-level guide plate II 7.2 does not contact the lower-level guide plate II 7.2. After the material enters the primary carbonization chamber 7 from the primary carbon inlet 7.1, it flows through different levels of guide plates II 7.2 in sequence, thereby allowing the material to remain in the primary carbonization chamber 7 for a sufficient time for carbonization. The bottom of the primary carbonization chamber 7 is funnel-shaped, and the center of the funnel-shaped bottom is the primary carbon outlet 7.5. The primary carbonization product finally enters the secondary carbonization chamber 8, which is connected to the primary carbonization chamber 7, through the primary carbon outlet 7.5.

[0065] The secondary carbonization chamber 8 includes a secondary carbonization chamber shell and multi-stage guide plates III 8.2 disposed within the shell. The structure of the multi-stage guide plates III 8.2 is the same as that of the multi-stage guide plates II 7.2 in the primary carbonization chamber 7, both being staggered and oppositely arranged, and will not be described further. After entering the secondary carbonization chamber 8, the primary carbonization product flows sequentially through different levels of guide plates III 8.2, allowing it to remain in the secondary carbonization chamber 8 for a sufficient time for secondary carbonization. The bottom of the secondary carbonization chamber 8 is also funnel-shaped, with a secondary carbon outlet 8.3 located in the center of the funnel-shaped bottom. The secondary carbonization product ultimately enters the activation chamber 9, which is connected to the secondary carbonization chamber 8, through the secondary carbon outlet 8.3.

[0066] The secondary carbonization chamber shell is sequentially arranged with a combustion chamber 8.4, a secondary electric heating layer 8.5, and a secondary insulation layer 8.6, with the insulation layer 8.6 located on the outermost side. The insulation layer 8.6 can be made of ceramic fiber board. An igniter 8.7 is located in the lower part of the combustion chamber 8.4, and is connected to the combustion chamber 8.4. Above the igniter 8.7 is a non-condensable gas pipe 12.11 exhaust port, which connects to the non-condensable gas outlet 12.7 on the liquefaction device 12. Below the igniter 8.7 is an air pipeline 8.10 exhaust port, which connects to a blower 8.11. The air pipeline 8.10 is also equipped with a regulating valve 8.12 and a flow meter 8.13. At the beginning of the waste plastic treatment process, the secondary electric heating layer 8.5 maintains the carbonization temperature inside the secondary carbonization chamber 8 at 500~600℃. After the waste plastic treatment process has been running for a period of time, the combustible gas generated by the system is introduced into the combustion chamber 8.4 and burned to generate heat to maintain the carbonization temperature of the secondary carbonization chamber 8. At this time, the heating power of the secondary electric heating layer 8.5 can be appropriately reduced. In addition, after the heat from the secondary carbonization chamber 8 enters the primary carbonization chamber 7 through the secondary carbon inlet 8.1, the heating power of the primary electric heating layer 7.3 can be appropriately reduced as needed to maintain the carbonization temperature of the primary carbonization chamber 7 at 200~300℃.

[0067] The secondary carbonization chamber 8 is also equipped with a nitrogen inlet 8.14 on its side wall. The nitrogen inlet 8.14 is connected to the second nitrogen cylinder 27. Nitrogen is introduced into the secondary carbonization chamber 8 and the primary carbonization chamber 7 through the second nitrogen cylinder 27 to maintain an oxygen-deficient atmosphere in the secondary carbonization chamber 8 and the primary carbonization chamber 7, so that the waste plastic can be carbonized.

[0068] The activation chamber 9 is located below the secondary carbonization chamber 8, and the secondary carbon outlet 8.3 is connected to the tertiary carbon inlet 9.1 at the top of the activation chamber 9. The activation chamber 9 includes an activation chamber shell, outside which are arranged a tertiary electric heating layer 9.2 and a tertiary insulation layer 9.3, with the tertiary insulation layer 9.3 located on the outermost side. The tertiary insulation layer 9.3 can be made of ceramic fiber board. The temperature of the activation chamber 9 is maintained at 800~900℃ by heating through the tertiary electric heating layer 9.2. The activation chamber 9 is equipped with multi-stage guide plates IV 9.4, whose arrangement is the same as that of the multi-stage guide plates II 7.2 in the primary carbonization chamber 7, both being staggered and opposite, and will not be described again. After entering the activation chamber 9, the secondary carbonization product flows through different levels of guide plates IV 9.4 in sequence, allowing the secondary carbonization product to remain in the activation chamber 9 for a sufficient time for activation. The bottom of the activation chamber 9 is funnel-shaped, and the bottom of the funnel-shaped chamber is provided with a three-stage carbon outlet 9.5. The three-stage carbon outlet 9.5 is connected to the feed port of the second screw conveyor 10. The discharge port of the second screw conveyor 10 is connected to the solid product collection device 11. The activated solid product enters the second screw conveyor 10 through the three-stage carbon outlet 9.5 and then enters the solid product collection device 11 through the second screw conveyor 10.

[0069] The outer wall of the casing of the second screw conveyor 10 is also provided with a cooling circulating water jacket 10.1, which has a first cooling water inlet 10.2 and a first cooling water outlet 10.3. Both the first cooling water inlet 10.2 and the first cooling water outlet 10.3 are connected to the cooling water circulation device 14. Since the material output from the third-stage carbon outlet 9.5 has a high temperature, the cooling circulating water jacket 10.1 is used to cool the second screw conveyor 10 in a timely manner to prevent the temperature from being too high and affecting the operation of the second screw conveyor 10.

[0070] Furthermore, thermocouples 22 and pressure gauges 34 are installed in the primary carbonization chamber 7, the secondary carbonization chamber 8, and the activation chamber 9. The thermocouples 22 and pressure gauges 34 are connected to an external controller to facilitate the detection of temperature and pressure in the primary carbonization chamber 7, the secondary carbonization chamber 8, and the activation chamber 9.

[0071] The first spiral discharger 6, the second spiral discharger 10, and the third spiral discharger 15 are all connected to drive motors, which drive the spiral blades inside the corresponding spiral dischargers to rotate and complete the material conveying.

[0072] The side wall of the primary carbonization chamber 7 is connected to the first pyrolysis gas discharge pipe 7.6, and the side wall of the secondary carbonization chamber 8 is connected to the second pyrolysis gas discharge pipe 8.8. The first pyrolysis gas discharge pipe 7.6 and the second pyrolysis gas discharge pipe 8.8 merge and are connected to the pyrolysis gas inlet 12.1 on the liquefaction device 12.

[0073] The liquefaction device 12 includes a condensation chamber 12.2, a liquefaction chamber 12.3, and a baffle plate 12.4. The condensation chamber 12.2 is closed at the top and bottom. A second cooling water inlet 12.5 is located on the lower part of the side wall of the condensation chamber 12.2, and a second cooling water outlet 12.6 is located on the upper part of the side wall of the condensation chamber 12.2. The second cooling water inlet 12.5 is connected to a cooling water circulation device 14, and the second cooling water outlet 12.6 is connected to a high-temperature water storage tank 23. The liquefaction chamber 12.3 is located inside the condensation chamber 12.2 (preferably in the center of the condensation chamber 12.2). Its top is closed, and its bottom is connected to a liquefaction product collection device 13 via a pipe, with a valve installed on the connecting pipe. The pyrolysis gas inlet 12.1 is preferably located in the lower part of the liquefaction chamber 12.3. The pyrolysis gas generated in the primary carbonization chamber 7 and the secondary carbonization chamber 8 enters the liquefaction chamber 12.3 through the pyrolysis gas inlet 12.1. Under the action of cooling circulating water, the condensable gas is condensed into liquid and enters the liquefaction product collection device 13, while the non-condensable gas is discharged from the non-condensable gas outlet 12.7. The liquefaction products in the liquefaction product collection device 13 are mainly composed of a mixture of C5 to C20 hydrocarbons, which can be utilized for high-value purposes, such as as fuel oil, chemical raw materials, or further processed into chemicals.

[0074] The baffle 12.4 is disposed at the top of the liquefaction chamber 12.3, and the outer diameter of the baffle 12.4 is equal to the inner diameter of the liquefaction chamber 12.3, so that the sidewall of the baffle 12.4 is in close contact with the inner sidewall of the liquefaction chamber 12.3. An arc-shaped gas channel 12.8 is provided in the baffle 12.4. The first opening 12.9 of the arc-shaped gas channel is located at the bottom of the baffle 12.4 and communicates with the liquefaction chamber 12.3. The second opening 12.10 of the arc-shaped gas channel is located on the sidewall of the baffle 12.4. The non-condensable gas outlet 12.7 is located on the upper part of the sidewall of the liquefaction chamber 12.3 and is located at the second opening 12.10 of the arc-shaped gas channel. The non-condensable gas outlet 12.7 communicates with the arc-shaped gas channel 12.8. The gas in liquefaction chamber 12.3 rises to the top of liquefaction chamber 12.3 and is then blocked by baffle 12.4. The baffle 12.4 allows the gas to remain in liquefaction chamber 12.3 for a longer time, thus ensuring complete liquefaction. The non-condensable gases (mainly composed of CO, H2, CH4, etc.) eventually enter the non-condensable gas outlet 12.7 through the arc-shaped gas channel 12.8 and are discharged through the non-condensable gas pipe 12.11.

[0075] Non-condensable gas pipe 12.11 connects to combustion chamber 8.4 of the secondary carbonization chamber 8, and the exhaust port of non-condensable gas pipe 12.11 is located above igniter 8.7. Air supplied through air pipe 8.10 provides oxygen to combustion chamber 8.4, while non-condensable gases (mainly composed of CO, H2, CH4, etc.) discharged from non-condensable gas pipe 12.11 enter combustion chamber 8.4 for combustion, thereby providing heat to the secondary carbonization chamber 8 and ensuring full utilization of non-condensable gases. The temperature of the secondary carbonization chamber 8 can be moderately adjusted and maintained within the set temperature range by regulating the flow rate of combustible gas and air entering combustion chamber 8.4.

[0076] The second cooling water outlet 12.6 is connected to the high-temperature water storage tank 23, and the high-temperature water discharged from it enters the high-temperature water storage tank 23. The first outlet 23.1 of the high-temperature water storage tank is connected to the inlet of the spiral coil 24, which is coiled and installed inside the secondary insulation layer 8.6 of the secondary carbonization chamber 8. The outlet of the spiral coil 24 is connected to the gas-liquid separator 25. The gas outlet of the gas-liquid separator 25 is connected to the first inlet of the gas mixing chamber 26, the second inlet of the gas mixing chamber 26 is connected to the second nitrogen cylinder 27, and the outlet of the gas mixing chamber 26 is connected to the activation chamber 9. The liquid outlet of the gas-liquid separator 25 is connected to the high-temperature water storage tank 23, and the second outlet 23.2 of the high-temperature water storage tank is connected to the cooling water circulation device 14. The spiral coil 24 is installed inside the secondary insulation layer 8.6. The high-temperature water in the high-temperature water storage tank 23 enters the spiral coil 24 and absorbs the heat of the secondary insulation layer 8.6, causing the temperature of the high-temperature water to rise further and vaporize into high-temperature water vapor, which enters the gas-liquid separator 25 through the outlet of the spiral coil 24.

[0077] The high-temperature water vapor separated by the gas-liquid separator 25 enters the gas mixing chamber 26 and mixes with nitrogen before entering the activation chamber 9, providing a nitrogen environment and high-temperature water vapor for the activation chamber 9. The water vapor volume in the gas mixing chamber 26 accounts for 20% to 50% of the total mixed gas volume, preferably 30% to 40%, thereby controlling the activation reaction within the activation chamber 9. The high-temperature water vapor reacts with the secondary carbonization products (mainly pyrolytic carbon) in the activation chamber 9 at high temperature to undergo a controllable carbon-water vapor activation reaction. This reaction takes place under an inert atmosphere in the activation chamber 9. By controlling the concentration of water vapor and the reaction time, the water vapor reacts with some of the carbon in the pyrolytic carbon, etching a well-developed microporous structure inside the pyrolytic carbon to form high-quality activated carbon. Simultaneously, water gas with CO and H2 as its main components (also containing a small amount of CO2 gas) is generated. The high-quality activated carbon enters the second screw conveyor 10 through the third-stage carbon outlet 9.5, and finally enters the solid product collection device 11 through the second screw conveyor 10. An activation chamber exhaust pipe 9.6 is installed on the side wall of the activation chamber 9, and the activation chamber exhaust pipe 9.6 is connected to the non-condensable gas pipe 12.11. The mixed gas (mainly CO, H2, and a small amount of CO2), excess water vapor, and a small amount of nitrogen generated in the activation chamber 9 enter the combustion chamber 8.4 of the secondary carbonization chamber 8 sequentially through the activation chamber exhaust pipe 9.6 and the non-condensable gas pipe 12.11. After combustion, it provides heat to the secondary carbonization chamber 8 and helps maintain the carbonization temperature of the secondary carbonization chamber 8. The exhaust gas generated by combustion enters the tail gas treatment device 17 through the exhaust gas discharge pipe 8.9, and the treated tail gas is discharged into the atmosphere.

[0078] In one embodiment, a flame arrester is also provided on the connecting pipe between the activation chamber exhaust pipe 9.6 and the non-condensable gas pipe 12.11 to prevent the flame from the combustion chamber 8.4 from spreading back to the activation chamber 9.

[0079] In one embodiment, the exhaust gas treatment device 17 is equipped with an alkaline spray absorption tower. The exhaust gas generated in the combustion chamber 8.4 enters the exhaust gas treatment device 17, and the acidic gas in the exhaust gas is absorbed and treated by the alkaline spray absorption tower. The purified gas meets the standards and is discharged into the air.

[0080] The high-temperature water separated by the gas-liquid separator 25 is pumped into the high-temperature water storage tank 23 by the water pump 30 for recycling. If there is too much high-temperature water in the high-temperature water storage tank 23, the water pump 30 at the second outlet 23.2 of the high-temperature water storage tank can be turned on to lead the high-temperature water in the high-temperature water storage tank 23 to the cooling water circulation device 14. The cooling water circulation device 14 is equipped with a cooler to cool the high-temperature water before recycling.

[0081] Preferably, a second star-shaped feeder 28 is connected between the secondary carbonization chamber 8 and the activation chamber 9. The inlet of the second star-shaped feeder 28 is connected to the secondary carbon outlet 8.3, and its outlet is connected to the tertiary carbon inlet 9.1. The secondary carbonization product is conveyed to the activation chamber 9 by the second star-shaped feeder 28. The second star-shaped feeder 28 serves to prevent gases (especially water vapor) in the activation chamber 9 from entering the secondary carbonization chamber 8, thus preventing any impact on the carbonization reaction in the secondary carbonization chamber 8.

[0082] Furthermore, valves 29 are installed on the first pyrolysis gas discharge pipe 7.6, the second pyrolysis gas discharge pipe 8.8, the gas outlet pipe of the first nitrogen cylinder 6.2, the gas outlet pipe of the second nitrogen cylinder 27, the gas inlet pipe of the gas mixing chamber 26, the gas outlet pipe of the gas mixing chamber 26, the exhaust pipe of the activation chamber 9.6, the non-condensable gas pipe 12.11, and the water inlet pipe of the spiral coil 24. Water pumps 30 are installed on the water outlet of the spiral coil 24, the liquid outlet pipe of the gas-liquid separator 25, and the water outlet pipe of the second outlet 23.2 of the high-temperature water storage tank. Valves and water pumps can be reasonably installed on other pipes according to actual conditions and needs.

[0083] Support frames 31 (only one shown in the figure) are provided at the bottom or lower part of components such as the spherical outer shell 4.1, the shell 5.1, the return hopper 16, the first screw conveyor 6, the second screw conveyor 10, the third screw conveyor 15, the secondary carbonization chamber 8, the activation chamber 9, the liquefaction device 12, the first star feeder 21, the second star feeder 28, and the high-temperature water storage tank 23, serving a supporting function. It should be noted that the support frame 31 is not limited to the structure shown in the figure, and the actual support frame structure can be designed according to the components to be supported.

[0084] In one embodiment, the cross-sections of the primary carbonization chamber 7, the secondary carbonization chamber 8, and the activation chamber 9 are all circular, but this description is not intended to limit the invention.

[0085] Furthermore, the shell of the primary carbonization chamber can be made of 304 stainless steel, the shell of the secondary carbonization chamber can be made of 310S stainless steel, the shell of the activation chamber can be made of 310S stainless steel, the spiral coil 24 can be made of 304 stainless steel, and the inner wall of the activation chamber shell is also provided with a refractory lining, the refractory lining material can be high alumina castable or corundum brick.

[0086] The methods for treating waste plastics using the above-mentioned waste plastic grading and carbonization devices include:

[0087] S1. Waste plastic enters the crushing device 2 from the feed hopper 1 for primary crushing. After primary crushing, the particle size of the waste plastic is approximately 5-10 cm. It then enters the grinding device 3 to further refine the particle size. After grinding, the particle size of the waste plastic is approximately 1-5 mm. The ground material falls onto the porous screen 4.4 of the screening device 4 under gravity. The material with a particle size smaller than the mesh size of the porous screen 4.4 (fine particle size material) passes through the mesh size of the porous screen 4.4 and enters the inner cavity of the spherical inner shell 4.2 of the screening device 4, and falls onto the bearing surface 5.3 of the catalyst adaptive proportioning device 5 connected to the bottom of the spherical inner shell 4.2. The material with a particle size larger than the mesh size of the porous screen 4.4 (large particle size material) falls along the cavity between the spherical inner shell 4.2 and the spherical outer shell 4.1 and enters the guide chamber 4.3 connected to the bottom of the spherical outer shell 4.1, and then enters the third screw conveyor 15. After being output by the third screw conveyor 15, the large particle size material enters the return hopper 16. The large particle size material in the return hopper 16 is periodically fed into the feed hopper 1 by the operator for further crushing and grinding until the particle size is small enough and finally falls onto the bearing surface 5.3 of the catalyst adaptive proportioning device 5.

[0088] S2. After the screened fine-particle material falls onto the bearing surface 5.3 of the sliding member 5.2 of the catalyst adaptive proportioning device 5, a certain gravity is applied to the bearing surface 5.3 of the sliding member 5.2, causing the entire sliding member 5.2 to compress the spring 5.5 and slide downward along the groove 5.6 on the inner side wall of the shell 5.1. After the entire sliding member 5.2 moves downward, the catalyst outlet 5.10 on the catalyst storage tube 5.9 is exposed on the bearing surface 5.3. The catalyst is automatically released to the bearing surface 5.3 and initially mixed with the material on the bearing surface 5.3. The initially mixed material enters the collection bin 19 through the bearing surface outlet 5.7, the inner sleeve 5.8, and the outer sleeve 5.16. Then it enters the first screw conveyor 6 through the one-way valve 20, and then enters the first star feeder 21 located below the outlet of the first screw conveyor 6. The first star feeder 21 transports the mixed material (including waste plastic and catalyst) to the first-stage carbonization chamber 7.

[0089] S3, waste plastics, and catalyst flow sequentially through different levels of guide plates II 7.2 in the primary carbonization chamber 7 for thorough carbonization. The primary carbonized solid product enters the secondary carbonization chamber 8 through the primary carbon outlet 7.5 and flows sequentially through different levels of guide plates III 8.2 within the secondary carbonization chamber 8 for thorough secondary carbonization. The secondary carbonized solid product enters the second star feeder 28 through the secondary carbon outlet 8.3, which transports the secondary carbonized solid product to the activation chamber 9. In the high-temperature activation chamber 9, the secondary carbonized solid product undergoes a controllable carbon-water vapor activation reaction with high-temperature water vapor. The water vapor reacts with some of the carbon in the pyrolytic carbon, etching a well-developed microporous structure inside the pyrolytic carbon to form high-quality activated carbon. Simultaneously, water gas with CO and H2 as the main components (also containing a small amount of CO2 gas) is generated. The high-quality activated carbon enters the second screw conveyor 10 through the tertiary carbon outlet 9.5 and finally enters the solid product collection device 11 through the second screw conveyor 10. The water gas (containing a small amount of CO2 gas), mainly composed of CO and H2, generated in the activation chamber 9, along with excess water vapor and a small amount of nitrogen, sequentially enters the combustion chamber 8.4 of the secondary carbonization chamber 8 via the activation chamber exhaust pipe 9.6 and the non-condensable gas pipe 12.11. After combustion, it provides heat to the secondary carbonization chamber 8, helping to maintain the carbonization temperature of the secondary carbonization chamber 8. The exhaust gas generated by combustion enters the tail gas treatment device 17 via the exhaust gas discharge pipe 8.9, and the treated tail gas is discharged into the atmosphere.

[0090] The gaseous products generated in the primary carbonization chamber 7 and the secondary carbonization chamber 8 enter the liquefaction unit 12 through the first pyrolysis gas discharge pipe 7.6 and the second pyrolysis gas discharge pipe 8.8, respectively.

[0091] S4. The condensable gas entering the liquefaction unit 12 is liquefied under the action of cooling water. The liquefied products enter the liquefied product collection device 13, where they can be utilized for high-value purposes. Non-condensable gases (mainly composed of CO, H2, CH4, etc.) are discharged from the non-condensable gas outlet 12.7 above the liquefaction chamber 12.3 and enter the combustion chamber 8.4 through the non-condensable gas pipeline 12.11. At the same time, air is introduced into the combustion chamber 8.4 through the air pipeline 8.10. The non-condensable gases are ignited by the igniter 8.7 to generate heat, which helps maintain the carbonization temperature of the secondary carbonization chamber 8.

[0092] The high-temperature water discharged from the second cooling water outlet 12.6 of the liquefaction unit 12 enters the high-temperature water storage tank 23, and then enters the spiral coil 24 coiled within the secondary insulation layer 8.6 of the secondary carbonization chamber 8. Under high temperature, the temperature of the high-temperature water further rises and vaporizes to form high-temperature water vapor. The high-temperature water and high-temperature water vapor enter the gas-liquid separator 25 through the outlet of the spiral coil 24. The high-temperature water vapor separated by the gas-liquid separator 25 enters the gas mixing chamber 26 and mixes with nitrogen before entering the activation chamber 9, providing a nitrogen environment and high-temperature water vapor for the activation chamber 9. The high-temperature water vapor reacts with the secondary carbonization products (mainly pyrolytic carbon) in the activation chamber 9 under high temperature to form high-quality activated carbon and water gas with CO and H2 as the main components (also containing a small amount of CO2 gas). The high-temperature water separated by the gas-liquid separator 25 is pumped into the high-temperature water storage tank 23 by the water pump 30 for recycling. If there is too much high-temperature water in the high-temperature water storage tank 23, turn on the water pump 30 at the second outlet 23.2 of the high-temperature water storage tank to lead the high-temperature water in the high-temperature water storage tank 23 to the cooling water circulation device 14. The cooling water circulation device 14 is equipped with a cooler to cool the high-temperature water and then recycle it.

[0093] It should be noted that at the beginning of the reaction, the primary electric heating layer 7.3, secondary electric heating layer 8.5, and tertiary electric heating layer 9.2 can be activated first to maintain the primary carbonization chamber 7, secondary carbonization chamber 8, and activation chamber 9 within the set temperature range. Nitrogen gas is then circulated through the first nitrogen cylinder 6.2 and the second nitrogen cylinder 27 for a period of time to maintain an oxygen-deficient environment in the primary carbonization chamber 7, secondary carbonization chamber 8, and activation chamber 9. After the reaction has continued for a period of time, with the generation of pyrolysis gas, non-condensable gas, and water gas, the igniter 8.7 of the combustion chamber 8.4 is activated. Combustible gases (mainly non-condensable gas and water gas) burn in the combustion chamber 8.4 to generate heat. At this time, the heating power of the primary electric heating layer 7.3 and secondary electric heating layer 8.5 can be appropriately reduced, relying on the heat generated by combustion in the combustion chamber 8.4 to maintain the carbonization temperature of the primary carbonization chamber 7 and secondary carbonization chamber 8. After the reaction has continued for a period of time, the nitrogen flow rate into the secondary carbonization chamber 8 can be appropriately reduced as needed. If the gas pressure in the primary carbonization chamber 7, the secondary carbonization chamber 8, and the activation chamber 9 is too high, the pressure can be appropriately released through the pressure relief valve 32.

[0094] This invention achieves graded carbonization of waste plastics through the above scheme, obtaining high-value-added activated carbon, combustible gas and liquefied products, thus realizing the resource utilization of waste plastics.

[0095] The above description is merely an embodiment of the present invention and is not intended to limit the present invention in any way. The present invention can also have other embodiments based on the above structure and function, which will not be listed hereafter. Therefore, any simple modifications, equivalent changes, and alterations made by those skilled in the art to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A waste plastic grading and carbonization device, characterized in that, The system includes a feed hopper (1), a crushing device (2), a grinding device (3), a screening device (4), a catalyst adaptive proportioning device (5), a first screw conveyor (6), a primary carbonization chamber (7), a secondary carbonization chamber (8), an activation chamber (9), a second screw conveyor (10), a solid product collection device (11), a liquefaction device (12), a liquefied product collection device (13), a cooling water circulation device (14), a third screw conveyor (15), a return hopper (16), and a tail gas treatment device (17). The feed hopper (1), crushing device (2), and grinding device (3) are arranged sequentially from top to bottom inside the casing (18). The bottom of the casing (18) is connected to the screening device (4). The screening device (4), the catalyst adaptive proportioning device (5), and the first screw conveyor (6) are all part of the system. The spiral discharge machine (6) is connected from top to bottom. The first spiral discharge machine (6) is also connected to the first carbonization chamber (7) through the first star feeder (21). The first carbonization chamber (7), the second carbonization chamber (8), the activation chamber (9), the second spiral discharge machine (10), and the solid product collection device (11) are connected from top to bottom. The first carbonization chamber (7) and the second carbonization chamber (8) are also connected to the liquefaction device (12). The liquefaction device (12) is connected to the liquefied product collection device (13) and the cooling water circulation device (14). The cooling water circulation device (14) is also connected to the second spiral discharge machine (10). The screening device (4) is also connected to the return silo (16) through the third spiral discharge machine (15). The tail gas treatment device (17) is connected to the second carbonization chamber (8). The catalyst adaptive proportioning device (5) includes a housing (5.1), a sliding member (5.2) is provided inside the housing (5.1), the top of the sliding member (5.2) is a bearing surface (5.3), the bearing surface (5.3) is inclined towards the center to form a funnel shape; the bottom of the sliding member (5.2) is a horizontally arranged support panel (5.4), at least two springs (5.5) are installed between the bottom of the support panel (5.4) and the bottom of the housing (5.1), and the outer wall of the sliding member (5.2) is perpendicular to the horizontal plane. The sliding part (5.2) is slidably connected to the outer wall of the housing (5.1); the bearing surface (5.3) is provided with a bearing surface outlet (5.7) in the middle, the bottom of the bearing surface outlet (5.7) is connected to the inner sleeve (5.8), the inner sleeve (5.8) is fitted inside the outer sleeve (5.16) and is slidably connected to the outer sleeve (5.16), the bottom of the outer sleeve (5.16) is connected to the collection bin (19), and the collection bin (19) is connected to the feed port of the first spiral discharge machine (6); A catalyst storage tube (5.9) is vertically inserted through the sliding member (5.2). The bottom of the catalyst storage tube (5.9) is fixedly connected to the bottom of the shell (5.1). Multiple catalyst outlets (5.10) are provided in the upper part of the side wall of the catalyst storage tube (5.9). When there is no material on the bearing surface (5.3) of the sliding member (5.2), the catalyst outlets (5.10) are blocked in the sliding member (5.2). After the bearing surface (5.3) is subjected to the gravity of the material, the sliding member (5.2) compresses the spring (5.5) and slides downward along the inner side wall of the shell (5.1). After the sliding member (5.2) moves downward as a whole, the catalyst outlets (5.10) are blocked. 0) The exposed bearing surface (5.3) is released to the bearing surface (5.3) and mixed with the material on the bearing surface (5.3). The mixed material enters the collection bin (19) through the bearing surface outlet (5.7), inner sleeve (5.8) and outer sleeve (5.16), and then enters the first screw feeder (6) and the first star feeder (21) in sequence. It is then transported to the first carbonization chamber (7) by the first star feeder (21). Each catalyst storage pipe (5.9) is connected to a catalyst loading pipe (5.11) at the top. The catalyst loading pipe (5.11) is connected to the catalyst feeding bin (5.14) through the catalyst conveying pipe (5.12).

2. The waste plastic grading and carbonization device as described in claim 1, characterized in that, The screening device (4) includes a spherical outer shell (4.1) and a spherical inner shell (4.2). The top of the spherical outer shell (4.1) is connected to the bottom of the casing (18). The bottom of the spherical outer shell (4.1) is connected to a flow guide chamber (4.3). The bottom of the flow guide chamber (4.3) is inclined downward. The flow guide chamber (4.3) is also connected to the third screw conveyor (15). The top of the spherical inner shell (4.2) is provided with a perforated screen (4.4) in the horizontal direction. The bottom of the spherical inner shell (4.2) is connected to the catalyst adaptive proportioning device (5).

3. The waste plastic grading and carbonization device as described in claim 1, characterized in that, The primary carbonization chamber (7) includes a primary carbonization chamber shell and multi-stage guide plates II (7.2) arranged alternately inside the primary carbonization chamber shell. A primary electric heating layer (7.3) and a primary insulation layer (7.4) are sequentially arranged outside the primary carbonization chamber shell. The secondary carbonization chamber (8) includes a secondary carbonization chamber shell and multi-stage guide plates III (8.2) arranged alternately inside the secondary carbonization chamber shell. A combustion chamber (8.4), a secondary electric heating layer (8.5), and a secondary insulation layer (8.6) are sequentially arranged outside the secondary carbonization chamber shell. An igniter (8.7) is installed in the lower part of the combustion chamber (8.4); the activation chamber (9) includes an activation chamber shell, and a three-stage electric heating layer (9.2) and a three-stage heat preservation layer (9.3) are arranged in sequence outside the activation chamber shell. The activation chamber (9) is equipped with a multi-stage guide plate IV (9.4) arranged in a staggered manner; a three-stage carbon outlet (9.5) is provided at the bottom of the activation chamber (9), and the three-stage carbon outlet (9.5) is connected to the feed port of the second screw conveyor (10), and the discharge port of the second screw conveyor (10) is connected to the solid product collection device (11).

4. The waste plastic grading and carbonization device as described in claim 3, characterized in that, An exhaust port for a non-condensable gas pipe (12.11) is provided above the igniter (8.7), and the non-condensable gas pipe (12.11) is connected to the non-condensable gas outlet (12.7) on the liquefaction device (12); an exhaust port for an air line (8.10) is provided below the igniter (8.7), and the air line (8.10) is connected to the blower (8.11); A nitrogen inlet (8.14) is also provided on the side wall of the secondary carbonization chamber, and the nitrogen inlet (8.14) is connected to the second nitrogen cylinder (27); a second star feeder (28) is also connected between the secondary carbonization chamber (8) and the activation chamber (9).

5. The waste plastic grading and carbonization device as described in claim 1, characterized in that, The outer wall of the casing of the second screw conveyor (10) is also provided with a cooling circulation water jacket (10.1). The cooling circulation water jacket (10.1) is provided with a first cooling water inlet (10.2) and a first cooling water outlet (10.3). The first cooling water inlet (10.2) and the first cooling water outlet (10.3) are both connected to the cooling water circulation device (14).

6. The waste plastic grading and carbonization device as described in claim 1, characterized in that, The first carbonization chamber (7) is connected to a first pyrolysis gas discharge pipe (7.6) on its side wall, and the second carbonization chamber (8) is connected to a second pyrolysis gas discharge pipe (8.8) on its side wall. The first pyrolysis gas discharge pipe (7.6) and the second pyrolysis gas discharge pipe (8.8) merge and connect to the pyrolysis gas inlet (12.1) on the liquefaction device (12). The liquefaction device (12) includes a condensation chamber (12.2), a liquefaction chamber (12.3), and a baffle plate (12.4). A second cooling water inlet (12.5) is provided on the lower part of the side wall of the condensation chamber (12.2), and a second cooling water inlet (12.5) is provided on the upper part of the side wall of the condensation chamber (12.2). A second cooling water outlet (12.6) is provided; a second cooling water inlet (12.5) is connected to a cooling water circulation device (14), and a second cooling water outlet (12.6) is connected to a high-temperature water storage device (23); a liquefaction chamber (12.3) is located in the inner cavity of a condensation chamber (12.2), with its top closed and its bottom connected to a liquefaction product collection device (13); a baffle plate (12.4) is located on top of the liquefaction chamber (12.3); an arc-shaped gas channel (12.8) is provided in the baffle plate (12.4), and a non-condensable gas outlet (12.7) is connected to the arc-shaped gas channel (12.8).

7. The waste plastic grading and carbonization device as described in claim 6, characterized in that, The first outlet (23.1) of the high-temperature water storage unit is connected to the inlet of the spiral coil (24). The spiral coil (24) is coiled and installed in the secondary insulation layer (8.6) of the secondary carbonization chamber (8). The outlet of the spiral coil (24) is connected to the gas-liquid separator (25). The gas outlet of the gas-liquid separator (25) is connected to the first air inlet of the gas mixing chamber (26). The second air inlet of the gas mixing chamber (26) is connected to the second nitrogen cylinder (27). The gas outlet of the gas mixing chamber (26) is connected to the activation chamber (9). The liquid outlet of the gas-liquid separator (25) is connected to the high-temperature water storage unit (23). The second outlet (23.2) of the high-temperature water storage unit is connected to the cooling water circulation device (14).

8. A method for treating waste plastics, characterized in that, The waste plastic grading and carbonization device according to any one of claims 1-7 is used for the treatment, and the specific treatment method includes: S1. Waste plastic enters the crushing device (2) from the feed hopper (1) for primary crushing, and then enters the grinding device (3) for further particle size refinement. The ground material falls onto the porous screen (4.4) of the screening device (4) under gravity. Fine particles pass through the mesh of the porous screen (4.4) into the inner cavity of the spherical inner shell (4.2) and fall onto the bearing surface (5.3) of the catalyst adaptive proportioning device (5) connected to the bottom of the spherical inner shell (4.2). Large particles... The material falls through the cavity between the spherical inner shell (4.2) and the spherical outer shell (4.1) and enters the guide chamber (4.3), and then enters the third screw conveyor (15). After being output by the third screw conveyor (15), the large-diameter material enters the return hopper (16). The large-diameter material in the return hopper (16) is periodically fed into the feed hopper (1) by the operator for further crushing and grinding until the material particle size is small enough and finally falls onto the bearing surface (5.3) of the catalyst adaptive proportioning device (5). S2. After the screened fine-particle material falls onto the bearing surface (5.3) of the sliding part (5.2), a certain gravity is applied to the bearing surface (5.3), causing the sliding part (5.2) to compress the spring (5.5) and slide downward along the inner wall of the shell (5.1). After the sliding part (5.2) moves down, the catalyst outlet (5.10) on the catalyst storage tube (5.9) is exposed on the bearing surface (5.3). The catalyst is released to the bearing surface (5.3) and mixed with the material on the bearing surface (5.3). The mixed material enters the collection bin (19) through the bearing surface outlet (5.7), inner sleeve (5.8), and outer sleeve (5.16), then enters the first screw conveyor (6), and finally enters the first-stage carbonization chamber (7). S3. Waste plastics and catalysts are fully carbonized in the primary carbonization chamber (7). The primary carbonization solid products enter the secondary carbonization chamber (8) for full secondary carbonization. The secondary carbonization solid products enter the activation chamber (9). After activation, high-quality activated carbon and water gas with CO and H2 as the main components are formed. The high-quality activated carbon enters the solid product collection device (11) through the second screw conveyor (10). The water gas, excess water vapor and a small amount of nitrogen generated during activation enter the combustion chamber (8.4) of the secondary carbonization chamber (8). After combustion, they provide heat to the secondary carbonization chamber (8) and help maintain the carbonization temperature of the secondary carbonization chamber (8). The exhaust gas generated during combustion enters the tail gas treatment device (17). The treated tail gas is discharged into the air. The gaseous products generated by the primary carbonization chamber (7) and the secondary carbonization chamber (8) enter the liquefaction device (12) through the first pyrolysis gas discharge pipe (7.6) and the second pyrolysis gas discharge pipe (8.8), respectively. S4. The condensable gas entering the liquefaction device (12) is liquefied under the action of cooling water. The liquefied products enter the liquefied product collection device (13). The non-condensable gas is discharged from the non-condensable gas outlet (12.7) and then enters the combustion chamber (8.4). It is ignited by the igniter (8.7) to generate heat and help maintain the carbonization temperature of the secondary carbonization chamber (8). The high-temperature water discharged from the second cooling water outlet (12.6) of the liquefaction unit (12) enters the high-temperature water storage tank (23), and then enters the spiral coil (24) coiled in the secondary insulation layer (8.6) of the secondary carbonization chamber. Under the action of high temperature, the temperature of the high-temperature water rises further and vaporizes to form high-temperature water vapor. It enters the gas-liquid separator (25) through the outlet of the spiral coil (24). The high-temperature water vapor separated by the gas-liquid separator (25) enters the gas mixing chamber (26) and mixes with nitrogen before entering the activation chamber (9). It provides the activation chamber (9) with nitrogen environment and high-temperature water vapor. The high-temperature water vapor and the secondary carbonization products in the activation chamber (9) undergo a carbon-water vapor activation reaction at high temperature to form high-quality activated carbon and water gas with CO and H2 as the main components. The high-temperature water separated by the gas-liquid separator (25) enters the high-temperature water storage tank (23) for recycling.

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