Retired fan blade pyrolysis tunnel kiln device and method

Abstract

The application discloses a retired fan blade pyrolysis tunnel kiln device and method, solves the problem that the existing technology is not suitable for large size blade treatment, has the beneficial effect of realizing the treatment of large pieces of blades, and is beneficial to large-scale production, and the specific scheme is as follows: the retired fan blade pyrolysis tunnel kiln device comprises a pretreatment kiln, a pyrolysis kiln and an oxidation kiln connected in sequence, the pretreatment kiln, the pyrolysis kiln and the oxidation kiln are respectively provided with inlets and outlets, the pretreatment kiln, the pyrolysis kiln and the oxidation kiln are respectively provided with conveying mechanisms to convey material containing parts, the material with a set length enters the pretreatment kiln, the pretreatment kiln sprays a swelling agent on the material to facilitate the cracking of the material and improve the subsequent pyrolysis speed, the material discharged from the outlet of the pretreatment kiln enters the pyrolysis kiln, the pyrolysis kiln is provided with protective gas, the material in the pyrolysis kiln is pyrolyzed to generate pyrolysis solids and pyrolysis gas under anoxic or hypoxic conditions, and the working temperature in the pyrolysis kiln is higher than that in the oxidation kiln.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology, and in particular to a tunnel kiln apparatus and method for pyrolysis of decommissioned wind turbine blades. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Wind turbine blades are one of the important components of wind power generation. They are mainly composed of materials such as glass fiber, carbon fiber, balsa wood and polyvinyl chloride (PVC). Among them, glass fiber and carbon fiber are thermosetting resin composite materials. Thermosetting composite materials have stable physical and chemical properties and are difficult to degrade in natural environment. Therefore, in order to avoid environmental pollution and waste of resources, retired wind turbine blades need to be recycled.

[0004] Commonly used recycling technologies include physical methods, chemical methods, and pyrolysis methods. Physical methods mainly involve mechanical recycling. During the recycling process, fibers are easily damaged, resulting in low fiber recovery rates. This makes it impossible to utilize fibers of different particle sizes on a large scale after processing, and the recycled products can only be reused at a lower grade, failing to achieve full utilization of resources. Chemical methods are more effective at recovering fibers and resins, but the solvents used are mostly toxic and expensive, reducing the applicability of this method.

[0005] Pyrolysis is a relatively good existing technology for recycling fibers. However, current pyrolysis equipment is mostly designed for processing decommissioned wind turbine blades broken into smaller particles, resulting in short recovered fiber lengths and reduced reuse value. For example, existing technologies include crushing decommissioned wind turbine blades to less than 200×100mm before pyrolysis to recover fibers, and crushing them to less than 50mm before using a rotary kiln pyrolysis furnace. Some solutions use rotary walking beam pyrolysis furnaces, which are only suitable for small pieces of crushed material.

[0006] In other words, most existing technologies for pyrolysis of decommissioned wind turbine blades cannot meet the requirements for processing large-sized blades. Some solutions can adapt to the processing of large-sized blades, but they only have pyrolysis devices and do not form a large-scale production line. In this case, the decommissioned wind turbine blades are directly pyrolyzed without pretreatment. Direct pyrolysis requires high pyrolysis temperature and prolongs the pyrolysis time, which places high demands on the equipment, resulting in high manufacturing costs and high overall energy consumption. Therefore, the existing devices are not suitable for large-scale processing of decommissioned wind turbine blades. Moreover, direct pyrolysis can easily damage the fiber components in the decommissioned wind turbine blades due to high temperatures.

[0007] In addition, the existing pyrolysis and oxidation units are combined for processing, resulting in a complex overall structure. There is no suitable transfer device, and some transfer equipment has problems such as not being able to introduce gas or not being properly sealed during the transfer process. The inability to introduce gas results in the gas atmosphere in the transfer equipment being inconsistent with the gas atmosphere in the pyrolysis or oxidation equipment, which can easily affect the pyrolysis or oxidation results. If the seal is not tight, the gas in the pyrolysis can easily enter the oxidation unit, affecting the quality and efficiency of oxidation. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a tunnel kiln device for the pyrolysis of decommissioned wind turbine blades, which solves the problems of existing devices being unable to process large-sized blades and being difficult to scale up production, thereby achieving continuous and efficient processing of materials, recovering large-sized high-value fibers, and meeting the needs of large-scale industrialization.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0010] The decommissioned wind turbine blade pyrolysis tunnel kiln device includes a pretreatment kiln, a pyrolysis kiln, and an oxidation kiln connected in sequence. Each of the pretreatment kiln, pyrolysis kiln, and oxidation kiln has an inlet and an outlet. Each of the pretreatment kiln, pyrolysis kiln, and oxidation kiln has a conveying mechanism to transport material containers. Material of a predetermined length enters the pretreatment kiln, where a swelling agent is sprayed onto the material to facilitate material pyrolysis and increase the subsequent pyrolysis rate. The material discharged from the pretreatment kiln outlet enters the pyrolysis kiln, where a protective gas is introduced. Under anaerobic or hypoxic conditions, the material is pyrolyzed in the pyrolysis kiln to generate pyrolysis solids and pyrolysis gas. The pyrolysis solids enter the oxidation kiln to undergo an oxidation reaction. The operating temperature in the pyrolysis kiln is higher than that in the oxidation kiln.

[0011] As described above, in the decomposition tunnel kiln device for retired wind turbine blades, the pyrolysis kiln is connected to an incinerator to send the pyrolysis gas into the incinerator for combustion, the oxidation kiln is connected to the incinerator, and the gas generated by the oxidation reaction enters the incinerator for combustion, the incinerator is connected to a waste heat utilization device, the waste heat utilization device is connected to a flue gas purification device, and the incinerator is connected to the pyrolysis kiln and the oxidation kiln respectively through an induced draft device.

[0012] The waste heat utilization device is connected to the pyrolysis kiln and the oxidation kiln respectively.

[0013] As described above, in the decommissioned wind turbine blade pyrolysis tunnel kiln device, the pretreatment kiln, the pyrolysis kiln, and the oxidation kiln have the same external structure, and the connecting channels between the pretreatment kiln and the pyrolysis kiln, and between the pyrolysis kiln and the oxidation kiln, can be opened or closed.

[0014] The pretreatment kiln, pyrolysis kiln, and oxidation kiln are arranged along the same straight line, or they are arranged in an L-shape or a U-shape.

[0015] As described above, in the pyrolysis tunnel kiln device for decommissioned wind turbine blades, the pretreatment kiln includes a first kiln body. Multiple nozzles are arranged along the length of the first kiln body. A pretreatment swelling agent interface is provided on the side of the first kiln body, and the pretreatment swelling agent interface is connected to the nozzles. A first gas port is provided in the first kiln body for extracting the volatile swelling agent to promote the working shortening of the swelling agent, or for introducing flue gas to preheat the material or for introducing nitrogen to purge.

[0016] The pyrolysis tunnel kiln device for decommissioned wind turbine blades as described above includes a second kiln body. The top of the second kiln body is provided with multiple second gas ports to connect with the incinerator. The side of the second kiln body is provided with multiple first radiant heating tubes. The first radiant heating tubes pass through the second kiln body to pyrolyze the material in the pyrolysis kiln with gas at a set temperature.

[0017] As described above, the pyrolysis tunnel kiln device for decommissioned fan blades includes a third kiln body. The top of the third kiln body is provided with multiple third gas ports to connect with the incinerator. The third kiln body is provided with a hot air pipe to introduce air with a set temperature into the third kiln body. Multiple second radiant heating pipes are provided on the side of the third kiln body. The second radiant heating pipes pass through the third kiln body to heat the material in the oxidation kiln.

[0018] The third kiln body is equipped with a perforated plate with through holes that are connected to hot air pipes to facilitate the uniform entry of air into the oxidation kiln.

[0019] As described above, in the pyrolysis tunnel kiln device for decommissioned wind turbine blades, transition isolation devices are respectively provided between the pretreatment kiln and the pyrolysis kiln, and between the pyrolysis kiln and the oxidation kiln. Transition isolation devices are also provided at the inlet end of the pretreatment kiln and the outlet end of the oxidation kiln. The transition isolation device has a feed end or a discharge end. Only one feed end or discharge end of the transition isolation device is opened at a time. The feed end or discharge end of the transition isolation device is connected to and communicates with the inlet or outlet of the pretreatment kiln, pyrolysis kiln, or oxidation kiln. Valves are respectively provided at the feed end or discharge end.

[0020] The transition isolation device at the front of the pyrolysis kiln is supplied with a gas that is the same as the protective gas inside the pyrolysis kiln, and the transition isolation device at the front of the oxidation kiln is supplied with a gas that is the same as the reaction gas inside the oxidation kiln.

[0021] As described above, in the decommissioned fan blade pyrolysis tunnel kiln device, the transition isolation device includes a shell with an inlet and an outlet. A rotatable rotor is installed inside the shell. The rotor has an opening and a cavity that can accommodate the material container. When receiving the material container, the opening on the rotor can communicate with the feed end of the transition isolation device. A tray conveying mechanism is installed inside the rotor. The shell is provided with multiple fourth gas ports, which can communicate with the cavity at the rotor to introduce the protective gas into the rotor.

[0022] To ensure the sealing performance of the transition isolation device, a baffle is formed in the circumferential direction of the rotor cavity, with an opening located at the baffle. The area of ​​the baffle in the circumferential direction of the rotor is greater than 1 / 2 of the circumferential area of ​​the rotor and the area of ​​the opening, while the area of ​​the baffle is less than 4 / 5 of the circumferential area of ​​the rotor, so as to seal the inlet and / or outlet of the housing during rotor rotation.

[0023] The drive motor for the pallet conveyor is located at the bottom of the housing.

[0024] The decomposition tunnel kiln device for retired wind turbine blades described above is replaced by a transition isolation kiln. The length of the transition isolation kiln is shorter than that of the pretreatment kiln. The external structure of the transition isolation kiln is the same as that of the pretreatment kiln. The conveying mechanism is also provided inside the transition isolation kiln.

[0025] Secondly, the present invention also provides a method for pyrolyzing decommissioned wind turbine blades, using the aforementioned tunnel kiln apparatus for pyrolyzing decommissioned wind turbine blades, comprising the following:

[0026] Cut the retired wind turbine blades into materials with dimensions of 1500*1000*100mm ≤ material ≤ 2000*1500*100mm.

[0027] Materials are placed in a tray to form a material container;

[0028] The material container is conveyed to the pretreatment kiln, where a swelling agent is sprayed onto the material for pretreatment.

[0029] The pretreated material with swelling is fed into a pyrolysis kiln for pyrolysis. Under an oxygen-free / oxygen-deficient environment, the pyrolysis produces pyrolysis solids and pyrolysis gas.

[0030] After pyrolysis, the pyrolytic solids undergo an oxidation reaction inside the oxidation kiln.

[0031] The beneficial effects of the present invention are as follows:

[0032] 1) The tunnel kiln device provided by this invention includes a modular pretreatment kiln, a pyrolysis kiln, and an oxidation kiln. The pretreatment kiln sprays a swelling agent onto the material, which diffuses into the material and generates oxygen free radicals that attack the benzene ring structure of the epoxy resin. This helps to reduce the stability of the cross-linked structure of the epoxy resin in the blade and promotes subsequent pyrolysis. After the material is treated in the pretreatment kiln for a set time, it enters the pyrolysis kiln. The pyrolysis kiln pyrolyzes the pretreated material, causing the epoxy resin to gradually decompose into pyrolysis gas and pyrolysis solids. The pyrolysis solids enter the oxidation kiln for oxidation, causing the substances attached to the fiber surface to undergo an oxidation reaction to generate carbon dioxide, thus purifying the fiber. The entire process forms a continuous flow, which can realize the large-scale processing of large blades. The material is swollen first, which is beneficial to the subsequent pyrolysis operation. The pyrolysis temperature and pyrolysis time are controlled, reducing the requirements for equipment and facilitating large-scale production.

[0033] 2) In this invention, the pyrolysis kiln is connected to the incinerator, the oxidation kiln is connected to the incinerator, the incinerator is connected to the waste heat utilization device, and the waste heat utilization device is connected to the flue gas purification device. Thus, the pyrolysis gas generated by pyrolysis enters the incinerator for combustion, the gas generated by the oxidation reaction enters the incinerator for combustion, and the high-temperature flue gas generated is recovered and utilized through the waste heat utilization device. The waste heat utilization device is connected to the pyrolysis kiln and the oxidation kiln respectively to ensure the working temperature of the pyrolysis kiln and the oxidation kiln.

[0034] 3) The overall structure of this invention is reasonably arranged and adopts a modular structure. The pretreatment kiln, pyrolysis kiln and oxidation kiln are arranged along the same straight line, or the pretreatment kiln, pyrolysis kiln and oxidation kiln are arranged in an L-shape or U-shape, which is conducive to the layout in the factory and to large-scale industrial implementation.

[0035] 4) The pretreatment kiln structure in this invention is reasonably set, including a first kiln body, which is equipped with multiple nozzles and a first gas port. The first gas port can extract the volatile swelling agent vapor, or introduce nitrogen gas for purging to prevent oxygen residue, or introduce flue gas to preheat the material.

[0036] 5) The transition isolation device in this invention has a reasonable structure. A tray conveying mechanism is set inside the rotor. The rotor has a cavity, and the shell has multiple fourth gas ports. The fourth gas ports can communicate with the cavity at the rotor to introduce protective gas into the rotor. This ensures that the gas inside the transition isolation device is consistent with the gas in the next processing step, guaranteeing the smooth progress of processes such as pyrolysis and low-temperature oxidation. Only one of the feed end or discharge end of the transition isolation device is opened at a time to ensure sealing performance. The transition isolation device on the front side of the pyrolysis kiln introduces the same gas as the protective gas in the pyrolysis kiln, and the transition isolation device on the front side of the oxidation kiln introduces the same gas as the reaction gas in the oxidation kiln, so as to prevent the gas in the pyrolysis kiln from entering the oxidation kiln and affecting the oxidation efficiency and quality.

[0037] 6) The pyrolysis tunnel kiln device for decommissioned fan blades provided in this invention is suitable for processing materials (1500×1000×100mm to 2000×1500×100mm), which facilitates standardized production, assembly and expansion of the device. It is suitable for large-scale industrial continuous production. The recovered fibers are large in size and have excellent mechanical properties, which greatly improves their utilization value. The integrated design of each functional kiln reduces heat loss and improves processing efficiency. Attached Figure Description

[0038] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0039] Figure 1 This is a schematic diagram of the structural principle of the tunnel kiln device for pyrolysis of decommissioned wind turbine blades in Embodiment 1 of the present invention.

[0040] Figure 2 This is a top view of the tunnel kiln device for pyrolysis of decommissioned fan blades in Embodiment 1 of the present invention.

[0041] Figure 3 This is a three-dimensional schematic diagram of the tunnel kiln device for pyrolysis of decommissioned fan blades in Embodiment 1 of the present invention.

[0042] Figure 4 This is a side view of the pyrolysis tunnel kiln device for decommissioned fan blades in Embodiment 2 of the present invention.

[0043] Figure 5 This is a three-dimensional schematic diagram of the tunnel kiln device for pyrolysis of decommissioned fan blades in Embodiment 2 of the present invention.

[0044] Figure 6 This is a cross-sectional view of the transition isolation device in the pyrolysis tunnel kiln device for decommissioned fan blades in Embodiment 2 of the present invention.

[0045] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0046] Among them: 1. Material holding container, 11. Pallet, 12. Material;

[0047] 2. Transition isolation device; 21. Housing; 22. Rotor; 23. Support; 24. Feed end; 25. Discharge end; 26. Drive device; 27. Fourth gas port; 28. Pallet conveying mechanism; 29. ​​Driven sprocket; 210. Drive motor; 211. Drive sprocket.

[0048] 3. Pretreatment kiln; 31. First kiln body; 32. First gas inlet; 33. Pretreatment swelling agent interface; 34. First sensor assembly; 35. First conveying mechanism;

[0049] 4. Pyrolysis kiln; 41. Second kiln body; 42. Second gas inlet; 43. First radiant heating tube; 44. Second sensor assembly; 45. Second conveying mechanism.

[0050] 5. Oxidation kiln; 51. Third kiln body; 52. Third gas inlet; 53. Hot air pipe; 54. Second radiant heating pipe; 55. Third conveying mechanism; 56. Third sensor assembly.

[0051] 6. Transition isolation kiln; 61. Gate valve; 62. Transition kiln; 63. Fourth conveying mechanism;

[0052] 7. Cooling device; 8. Exhaust fan device; 9. Incinerator; 10. Waste heat recovery device; 110. Flue gas purification device. Detailed Implementation

[0053] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0054] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0055] As described in the background section, the existing technology for treating decommissioned wind turbine blades is not suitable for treating larger blades. In order to solve the above technical problem, this invention proposes a tunnel kiln device for the pyrolysis of decommissioned wind turbine blades.

[0056] Example 1

[0057] In a typical embodiment of the present invention, reference is made to Figure 1 , Figure 2 and Figure 3As shown, the decommissioned wind turbine blade pyrolysis tunnel kiln device includes a pretreatment kiln 3, a pyrolysis kiln 4, and an oxidation kiln 5 connected in sequence. The pretreatment kiln 3, pyrolysis kiln 4, and oxidation kiln 5 are respectively provided with inlets and outlets. Conveying mechanisms are respectively provided inside the pretreatment kiln 3, pyrolysis kiln 4, and oxidation kiln 5 to convey material containers 1. Material of a set length enters the pretreatment kiln 3. The pretreatment kiln 3 sprays a swelling agent on the material to facilitate material pyrolysis. The material discharged from the outlet of the pretreatment kiln 3 enters the pyrolysis kiln 4. A protective gas is introduced into the pyrolysis kiln 4. The pyrolysis kiln 4 pyrolyzes the material to generate pyrolysis solids and pyrolysis gas. The pyrolysis solids enter the oxidation kiln 5 to undergo an oxidation reaction. The working temperature inside the pyrolysis kiln 4 is higher than the working temperature inside the oxidation kiln 5.

[0058] The swelling agent used is an existing epoxy resin stripping agent. Through diffusion, the swelling agent reduces the stability of the epoxy resin cross-linking structure and generates oxygen free radicals that attack the benzene ring structure, promoting the conversion of large-molecule aromatic products into small-molecule olefins and accelerating the decomposition of the epoxy resin. The swelling treatment causes the dense structure of the blade to expand and layer, resulting in a porous surface. This effectively improves heat and mass transfer during the depolymerization process, accelerates resin decomposition, inhibits the formation of pyrolysis carbon, lowers the oxidation temperature, and significantly improves the mechanical properties of the regenerated fiber.

[0059] The pyrolysis kiln 4 is connected to the incinerator 9 to send the pyrolysis gas into the incinerator 9 for combustion. The oxidation kiln 5 is connected to the incinerator 9, and the gas produced by the oxidation reaction enters the incinerator 9 for combustion. The incinerator 9 is connected to the waste heat utilization device 10, and the waste heat utilization device 10 is connected to the flue gas purification device 110. The incinerator is connected to the pyrolysis kiln 4 and the oxidation kiln 5 respectively through an induced draft device. The waste heat utilization device 10 is connected to the pyrolysis kiln 4 and the oxidation kiln 5 respectively to utilize the temperature of the high-temperature flue gas. The waste heat utilization device 10 adopts an existing waste heat utilization device, and the flue gas purification device 110 adopts an existing treatment process and equipment adapted to the composition and characteristics of the flue gas.

[0060] In addition, transition isolation devices 2 are respectively set between the pretreatment kiln 3 and the pyrolysis kiln 4, and between the pyrolysis kiln 4 and the oxidation kiln 5. Transition isolation devices 2 are also set at the inlet end of the pretreatment kiln 3 and the outlet end of the oxidation kiln 5. The transition isolation device 2 has a feed end or a discharge end. The feed end or discharge end of the transition isolation device 2 is connected to the inlet or outlet of the pretreatment kiln 3, the pyrolysis kiln 4, or the oxidation kiln 5. Valves are respectively set at the feed end or the discharge end. A transition isolation device 2 is also set at the outlet of the oxidation kiln 5. The transition isolation device 2 is connected to the cooling device 7. The cooling device 7 is a cooling device in the prior art.

[0061] To ensure modular structure and facilitate industrial processing, the pretreatment kiln 3, pyrolysis kiln 4 and oxidation kiln 5 have the same external structure. The connecting channels between the pretreatment kiln 3 and pyrolysis kiln 4, and between the pyrolysis kiln 4 and oxidation kiln 5 can be opened or closed.

[0062] refer toFigure 1 As shown, the pretreatment kiln 3, pyrolysis kiln 4, and oxidation kiln 5 are arranged on a single processing line, all along the X-axis. Alternatively, they can be arranged in an L-shape or U-shape. To ensure the necessary environmental conditions for each kiln and to reduce heat loss, transition isolation devices 2 are installed at the front and rear ends of the processing line and between adjacent kilns (i.e., pretreatment kiln 3 and pyrolysis kiln 4, pyrolysis kiln 4 and oxidation kiln 5). The transition isolation device 2, pretreatment kiln 3, pyrolysis kiln 4, and oxidation kiln 5 together form a tunnel kiln device for decommissioned fan blades. The pretreatment kiln 3, pyrolysis kiln 4, and oxidation kiln 5 adopt a modular design, sharing the same structural form, differing only in their installation accessories.

[0063] refer to Figure 2 As shown, the material holding device 1 includes a tray 11, which is used to place the material 12. The material holding device 1 enters the tunnel kiln device along the X direction, and passes through the transition isolation device 2, the pretreatment kiln 3, the transition isolation device 2, the pyrolysis kiln 4, the transition isolation device 2, the oxidation kiln 5, and the transition isolation device 2 in sequence before being discharged.

[0064] refer to Figure 2 As shown, the transition isolation device 2 adopts a rotary valve structure, including a cylindrical housing 21 supported by a bracket 23, and a cylindrical rotor 22 disposed inside the housing 21. The rotor 22 has an opening and a cavity to accommodate the material container 1. When receiving the material container 1, the opening on the rotor 22 communicates with the feed end 24 of the transition isolation device 2, allowing the material container 1 to be conveyed into the rotor 22 through the feed end 24. During material reception, the rotor 22 and the discharge end 25 of the transition isolation device 2 are in a closed state. When receiving material, the tray conveying mechanism 28 disposed inside the rotor 22 is activated to receive the material container 1 into the internal space of the rotor 22.

[0065] Considering the layout of the structural space, refer to Figure 6 As shown, the pallet conveying mechanism 28 includes a drive motor 210. The drive shaft of the drive motor 210 passes through the bottom of the housing 21 and the bottom of the rotor 22 and enters the cavity of the rotor 22. The drive shaft is connected to the drive sprocket 211 in the pallet conveying mechanism 28 through a transmission component such as a gear transmission component. The drive sprocket 211 is located at both ends of the drive roller. The drive roller is supported by the housing 21. The drive sprocket 211 cooperates with the driven sprockets 29 at the ends of multiple rotating rollers through a chain. There are two chains. The drive sprocket 211 is set below the plane of the rotating roller. The two ends of the rotating roller pass through the driven sprockets 29 and are supported by the housing 21. The rotating roller is driven by the driven sprockets 29 to rotate. The material container 1 is received and delivered through multiple rotating rollers.

[0066] The rotary drive mechanism includes a drive unit 26, which is located on the top of the housing 21. The drive unit 26 passes through the housing 21 and is connected to the rotor 22. The housing 21 supports the rotor 22. The drive unit 26 can be a motor. The output end of the drive unit 26 passes through the top plate of the housing 21 and is connected to the rotor 22. The drive unit 26 drives the rotor 22 to rotate. Considering the closure of the inlet and outlet of the housing 21, the cavity is connected to the outside of the rotor. The rotor 22 is provided with a baffle in the circumference of the cavity. The height of the baffle and the height of the rotor 22 are greater than the height of the inlet or outlet of the housing 21. The area of ​​the baffle is greater than 1 / 2 of the circumferential area of ​​the rotor and the area of ​​the cavity opening. The area of ​​the baffle is less than 4 / 5 of the circumferential area of ​​the rotor, so as to close the inlet and / or outlet of the housing 21 during the rotation of the rotor 22.

[0067] When it is necessary to transport the material container 1 to the next process, the rotor 22 rotates 180° under the drive of the drive device 26, such as a drive motor. The opening inside the rotor 22 that accommodates the material container 1 is connected to the discharge end 25, while the feed end 24 is closed. Ribs are provided on both sides of the opening of the rotor 22, and sealing strips are provided on the top side of the ribs. During the rotation of the rotor 22, the ribs on both sides of the rotor 22, the sealing strips, and the inner wall of the housing 21 form a sealed space. After the opening inside the rotor 22 that accommodates the material container 1 is connected to the discharge end 25, the tray conveying mechanism 28 provided inside the rotor 22 is activated to transport the material container 1 to the next process.

[0068] The top of the transition isolation device 2 is provided with multiple fourth gas ports 27, which can communicate with the internal cavity of the rotor 22 during rotation or rest. These ports are used for auxiliary sealing and replacement of nitrogen / air, and can also continuously supply nitrogen to the pyrolysis kiln 4. The transition isolation device 2 on the front side of the pyrolysis kiln 4 is supplied with a gas consistent with the protective gas inside the pyrolysis kiln 4, and the transition isolation device 2 on the front side of the oxidation kiln 5 is supplied with a gas consistent with the reaction gas inside the oxidation kiln 5. This ensures the consistency between the gas in the transition isolation device 2 on the front side of the pyrolysis kiln 4 or the oxidation kiln 5 and the gas in the pyrolysis kiln 4 or oxidation kiln 5, preventing air from entering the pyrolysis kiln 4 and affecting the pyrolysis of the material 12, and also preventing the protective gas in the pyrolysis kiln 4, such as nitrogen, from entering the oxidation kiln 5.

[0069] refer to Figure 2 As shown, the pretreatment kiln 3 includes a first kiln body 31 with a set length. The top of the first kiln body 31 is provided with a first gas port 32, and multiple first gas ports 32 may be provided. Multiple first sensor assemblies 34 and multiple pretreatment swelling agent interfaces 33 are provided on the side of the first kiln body 31. The conveying mechanism supported by the first kiln body 31 is a first conveying mechanism 35.

[0070] The first gas inlet 32 ​​is used to extract the volatile swelling agent to promote the shortening of the swelling agent's working time, or to introduce high-temperature flue gas to preheat the material. Multiple first sensor assemblies 34 include, but are not limited to, temperature sensors, pressure sensors, and other sensor assemblies required for the pretreatment process. Multiple pretreatment swelling agent inlets 33 are used to connect the swelling agent and spray it onto the material surface. The first conveying mechanism 35 is used for the transfer of the material container 1 within the pretreatment kiln 3, as well as for receiving the material container 1 from the previous process and transferring it to the next process. The first conveying mechanism 35 can be a conventional conveying mechanism and is not limited to a specific structure; a chain conveyor mechanism is preferred.

[0071] refer to Figure 2 As shown, the pyrolysis kiln 4 includes a second kiln body 41. The top of the second kiln body 41 is provided with multiple second gas ports 42. The side of the second kiln body 41 is provided with multiple first radiant heating tubes 43. The side is also provided with multiple second sensor assemblies 44. The conveying mechanism provided inside the second kiln body 41 is a second conveying mechanism 45. The maximum pyrolysis temperature is ≤650℃, and the optimal temperature is 500℃. The first radiant heating tubes 43 are connected to the waste heat utilization device 10.

[0072] Multiple second gas ports 42 are used for the discharge of pyrolysis gas, the introduction of nitrogen, etc. Multiple first radiant heating tubes 43 are located above the material container 1 and are used to introduce gas at a set temperature to heat the material. Multiple second sensor assemblies 44 include, but are not limited to, temperature sensors, pressure sensors, oxygen concentration sensors, and other necessary sensor assemblies. A second conveying mechanism 45 is used for the transfer of the material container 1 within the pyrolysis kiln 4, as well as for receiving the material container 1 from the previous process and transferring it to the next process.

[0073] Material 12 is pyrolyzed in the pyrolysis kiln 4 under an oxygen-free / oxygen-deficient environment, producing pyrolysis solids and pyrolysis gas. The maximum pyrolysis temperature is ≤650℃, with 500℃ being optimal. Multiple first radiant heating tubes 43 (connected to the waste heat utilization device 10) are used to radiate heat the upper surface of material 12, but this method is not limited to this; microwave heating can also be used.

[0074] refer to Figure 2 As shown, oxidation kiln 5 is a low-temperature oxidation kiln. Oxidation kiln 5 includes a third kiln body 51, multiple third gas ports 52 provided on the top of the third kiln body 51, a hot air pipe 53 provided on the lower side of the third kiln body 51, a perforated plate provided inside the third kiln body 51, the perforated plate having through holes that communicate with the hot air pipe 53 to facilitate the uniform entry of air into the oxidation kiln 5, multiple second radiant heating pipes 54 provided on the side of the third kiln body 51, multiple third sensor assemblies 56 provided on the side of the third kiln body 51, a third conveying mechanism 55 provided inside the third kiln body 51, and the second radiant heating pipes 54 connected to the waste heat utilization device 10.

[0075] Multiple third gas inlets 52 are used for the discharge of oxidation flue gas, and hot air pipes 53 located on the lower side are used to supply oxygen into the oxidation kiln 5. However, they are not limited to being located on the lower side; for example, they can be located on the side or top to supply hot air. Multiple second radiant heating tubes 54 are located above the material container 1 for heating the material, or the second radiant heating tubes 54 are arranged in an S-shape inside the third kiln. Multiple third sensor assemblies 56 include, but are not limited to, temperature sensors, pressure sensors, oxygen concentration sensors, and other sensor assemblies. The third conveying mechanism 55 is used for the transfer of the material container 1 within the oxidation kiln 5, as well as for receiving the material container 1 from the previous process and transferring the material container 1 to the next process.

[0076] After pyrolysis, the pyrolytic carbon adhering to the fiber surface in the pyrolytic solid undergoes an oxidation reaction with oxygen in oxidation furnace 5. The temperature in oxidation furnace 5 is ≤500℃, eventually forming glass fiber.

[0077] The first conveying mechanism 35, the second conveying mechanism 45 and the third conveying mechanism 55 have the same structure. Multiple reinforcing plates can be set on the outside of the first kiln body 31, the second kiln body 41 and the third kiln body 51 to enhance the structural strength. Each reinforcing plate is set along the width direction of the corresponding kiln body.

[0078] The pyrolysis tunnel kiln device for decommissioned wind turbine blades provided in this embodiment adopts a modular structure. The material 12 moves in the tunnel kiln device under the support of the tray 11 and is processed in the pretreatment kiln 3, pyrolysis kiln 4 and oxidation kiln 5 in sequence to finally recover high-value fibers. The overall modular structure is conducive to large-scale industrial implementation.

[0079] Example 2

[0080] The difference between this embodiment and Embodiment 1 is that:

[0081] refer to Figure 4 and Figure 5 As shown, the transition isolation device 2 adopts the transition isolation kiln 6, which includes a transition kiln 62. A fourth conveying mechanism 63 is installed inside the transition kiln 62. The fourth conveying mechanism 63 has the same structure as the first conveying mechanism. Valves such as gate valves 61 are installed at both ends of the transition kiln 62. The gate valves 61 are used to control the opening or closing of the inlet and outlet at both ends of the transition kiln 62. The gate valves 61 are existing electric valves. The gate valves 61 are connected to a controller, which is a PLC controller or other type of controller. The controller controls the opening and closing of the gate valves 61.

[0082] The transition kiln 62 has the same structure as the pretreatment kiln 3, pyrolysis kiln 4, or oxidation kiln 5, but its length can only accommodate one material container 1. The pretreatment kiln 3, pyrolysis kiln 4, and oxidation kiln 5 can accommodate multiple material containers 1, for example, ≥3. The gate valves 61 at both ends of the transition isolation kiln 6 open and close alternately. When receiving materials, the upstream gate valve is open and the downstream gate valve is closed. After the material container 1 enters, the upstream gate valve closes. When conveying materials, the downstream gate valve is open and the upstream gate valve is closed. The fourth conveying mechanism 63 sends the materials to the next process. Gas isolation is achieved through the airtightness of the gate valves.

[0083] Example 3

[0084] This embodiment provides a method for pyrolysis of decommissioned wind turbine blades, including the following:

[0085] refer to Figure 1 As shown, the system for disposing of decommissioned wind turbine blades in a tunnel kiln device determines the cutting scheme based on the specific structural diagram or structural test results of the decommissioned wind turbine blades. The existing cutting equipment cuts the decommissioned wind turbine blades into materials with a size of 1500*1000*100mm ≤ 2000*1500*100mm. The materials are large pieces, and the purpose of cutting them into materials is to ensure that the internal fibers are longer and have higher recycling value.

[0086] After the decommissioned wind turbine blades are cut, the material 12 is placed in the tray 11 to form the material holding component 1, which is then used for subsequent processing. The material holding component 1 is driven by the tray conveying mechanism 28 in the transition isolation device 2, which can be an existing chain conveyor or a hydraulic / pneumatic drive mechanism. The material is then transported to the pretreatment kiln 3, where a swelling agent is sprayed onto the material for pretreatment.

[0087] The pretreated material undergoing swelling treatment enters the pyrolysis kiln 4 through another transitional isolation device 2 for pyrolysis. Under an oxygen-free / oxygen-deficient environment, pyrolysis produces pyrolysis solids and pyrolysis gas. The pyrolysis gas generated in the pyrolysis kiln 4 is extracted by the induced draft device 8 and transported to the incinerator 9 for combustion to produce high-temperature flue gas. After being heat-utilized by the waste heat utilization device 10, the high-temperature flue gas is discharged into the flue gas purification device 110 and discharged after meeting the standards. The pyrolysis solids are transported to the oxidation kiln 5 along with the material container 1 through the right-hand transitional isolation device 2.

[0088] After pyrolysis, the pyrolytic carbon adhering to the surface of the fibers in the pyrolytic solid undergoes an oxidation reaction with oxygen in the oxidation kiln, generating oxidized flue gas. This gas is extracted by the induced draft device 8 and transported to the incinerator 9 for combustion, producing high-temperature flue gas. After being processed by the waste heat utilization device 10, the high-temperature flue gas is discharged into the flue gas purification device 110 and discharged only after meeting the emission standards. The recovered fibers, after low-temperature oxidation to remove the pyrolytic carbon, are conveyed to the cooling device 7 via the transition isolation device 2 on the material container 1 for cooling. The cooling method uses cold air cooling, and the glass / carbon fiber is recovered after cooling.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A tunnel kiln device for pyrolysis of decommissioned wind turbine blades, characterized in that, The system includes a pretreatment kiln, a pyrolysis kiln, and an oxidation kiln connected in sequence. Each of the three kilns has an inlet and an outlet. Conveying mechanisms are installed inside each kiln to transport material containers. Material of a set length enters the pretreatment kiln, where a swelling agent is sprayed to facilitate material pyrolysis and increase the subsequent pyrolysis rate. The material discharged from the pretreatment kiln enters the pyrolysis kiln, where a protective gas is introduced. Under anaerobic or oxygen-deficient conditions, the material is pyrolyzed to generate pyrolysis solids and pyrolysis gas. The pyrolysis solids enter the oxidation kiln to undergo an oxidation reaction. The operating temperature inside the pyrolysis kiln is higher than that inside the oxidation kiln. The pretreatment kiln includes a first kiln body, with multiple nozzles arranged along the length of the first kiln body. A pretreatment swelling agent interface is provided on the side of the first kiln body, which is connected to the nozzles. A first gas port is provided in the first kiln body for extracting the volatile swelling agent to promote the working shortening of the swelling agent, or for introducing flue gas to preheat the material or for introducing nitrogen to purge. Transition isolation devices are set between the pretreatment kiln and the pyrolysis kiln, and between the pyrolysis kiln and the oxidation kiln. Transition isolation devices are also set at the inlet end of the pretreatment kiln and the outlet end of the oxidation kiln. The transition isolation device has a feed end or a discharge end. Only one feed end or discharge end of the transition isolation device is opened at a time. The feed end or discharge end of the transition isolation device is connected to the inlet or outlet of the pretreatment kiln, pyrolysis kiln or oxidation kiln. Valves are set at the feed end or discharge end respectively. The transition isolation device at the front of the pyrolysis kiln is introduced with the same gas as the protective gas inside the pyrolysis kiln, and the transition isolation device at the front of the oxidation kiln is introduced with the same gas as the reaction gas inside the oxidation kiln. The transition isolation device includes a housing with an inlet and an outlet. A rotatable rotor is installed inside the housing. The rotor has an opening and a cavity that can accommodate the material container. When receiving the material container, the opening on the rotor can communicate with the feed end of the transition isolation device. A tray conveying mechanism is installed inside the rotor. The housing is provided with multiple fourth gas ports, which can communicate with the cavity at the rotor to introduce the protective gas into the rotor. The rotor forms a baffle in the circumferential direction of the cavity, and the opening is located at the baffle. The area of ​​the baffle in the circumferential direction of the rotor is greater than 1 / 2 of the circumferential area of ​​the rotor and the area of ​​the opening. The area of ​​the baffle is less than 4 / 5 of the circumferential area of ​​the rotor, so as to seal the inlet and / or outlet of the shell during the rotation of the rotor. The drive motor for the pallet conveyor is located at the bottom of the housing.

2. The pyrolysis tunnel kiln apparatus for decommissioned wind turbine blades according to claim 1, characterized in that, The pyrolysis kiln is connected to the incinerator to send the pyrolysis gas into the incinerator for combustion. The oxidation kiln is connected to the incinerator, and the gas produced by the oxidation reaction enters the incinerator for combustion. The incinerator is connected to the waste heat utilization device, and the waste heat utilization device is connected to the flue gas purification device. The incinerator is connected to the pyrolysis kiln and the oxidation kiln respectively through an induced draft device.

3. The pyrolysis tunnel kiln apparatus for decommissioned wind turbine blades according to claim 1, characterized in that, The pretreatment kiln, the pyrolysis kiln, and the oxidation kiln have the same external structure, and the connecting channels between the pretreatment kiln and the pyrolysis kiln, and between the pyrolysis kiln and the oxidation kiln, can be opened or closed. The pretreatment kiln, pyrolysis kiln, and oxidation kiln are arranged along the same straight line, or they are arranged in an L-shape or a U-shape.

4. The pyrolysis tunnel kiln apparatus for decommissioned wind turbine blades according to claim 2, characterized in that, The pyrolysis kiln includes a second kiln body. The top of the second kiln body is provided with multiple second gas ports to connect with the incinerator. The side of the second kiln body is provided with multiple first radiant heating tubes. The first radiant heating tubes pass through the second kiln body to pyrolyze the material in the pyrolysis kiln with gas at a set temperature.

5. The pyrolysis tunnel kiln apparatus for decommissioned wind turbine blades according to claim 2, characterized in that, The oxidation kiln includes a third kiln body, with multiple third gas ports at the top of the third kiln body for connection to the incinerator. The third kiln body is equipped with a hot air pipe to introduce air with a set temperature into the third kiln body. Multiple second radiant heating pipes are provided on the side of the third kiln body, and the second radiant heating pipes pass through the third kiln body to heat the material inside the oxidation kiln. The third kiln body is equipped with a perforated plate with through holes that are connected to hot air pipes to facilitate the uniform entry of air into the oxidation kiln.

6. The pyrolysis tunnel kiln apparatus for decommissioned wind turbine blades according to claim 1, characterized in that, The transition isolation device is replaced by a transition isolation kiln, which is shorter than the pretreatment kiln. The external structure of the transition isolation kiln is the same as that of the pretreatment kiln, and the conveying mechanism is also installed inside the transition isolation kiln.

7. A method for pyrolyzing decommissioned wind turbine blades, characterized in that, The pyrolysis tunnel kiln apparatus for decommissioned wind turbine blades according to any one of claims 1-6 includes the following components: Cut the retired wind turbine blades into materials with dimensions of 1500*1000*100mm ≤ material ≤ 2000*1500*100mm. Materials are placed in a tray to form a material container; The material container is conveyed to the pretreatment kiln, where a swelling agent is sprayed onto the material for pretreatment. The pretreated material with swelling is fed into a pyrolysis kiln for pyrolysis. Under an oxygen-free / oxygen-deficient environment, the pyrolysis produces pyrolysis solids and pyrolysis gas. After pyrolysis, the pyrolytic solids undergo an oxidation reaction inside the oxidation kiln.

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