A pyrolytic recycling system and method for wind turbine blade glass fiber bundles

Abstract

The application discloses a pyrolysis recycling system and method for a wind power blade glass fiber bundle. The pyrolysis recycling system comprises feeding devices, a pyrolysis reactor, conveying devices and an oxidation reactor arranged in sequence in the transverse direction, a flue gas purification system, a first heat exchange device, a second heat exchange device, a pyrolysis oil recycling system and a burner. A double-chamber pyrolysis reactor is formed by horizontally combining a pyrolysis chamber and an oxidation reaction chamber arranged in sequence in the transverse direction. The gas phase components of the wind power blade pyrolyzed in the pyrolysis chamber are subjected to condensation treatment through the pyrolysis oil recycling system. The completely pyrolyzed materials are transferred to the oxidation reactor. The pyrolysis chamber is heated by using the hot air rising in the oxidation reaction chamber. The high-temperature flue gas generated after the pyrolysis gas is combusted is used to heat the oxidation reaction chamber through the second heat exchange device. A self-heating pyrolysis process is realized. The glass fiber bundle of the wind power blade is recycled and harmlessly treated.

Description

Technical Field

[0001] This invention relates to the field of resource recycling technology, and in particular to a pyrolysis recycling system and method for glass fiber bundles in wind turbine blades. Background Technology

[0002] Wind turbine blades are a crucial component of wind turbine units. The design life of wind turbine units is typically 20-25 years, and the ever-increasing installed capacity of wind power will inevitably lead to the replacement of a large number of decommissioned blades. Therefore, the disposal, treatment, and recycling of decommissioned wind turbine blades are urgently needed.

[0003] Currently, my country mainly relies on landfill and incineration for the disposal and recycling of retired wind turbine blades. While landfill is simple to operate and has low disposal costs, it pollutes groundwater and exacerbates the greenhouse effect. Incineration produces toxic gases such as dioxins, which pollute the atmosphere and affect human health. Pyrolysis involves heat-treating composite materials in air or an inert gas atmosphere, decomposing the organic matter into smaller organic molecules or gases, thereby recovering the fibers. The advantages of pyrolysis are its large processing capacity, relatively good fiber recovery performance, high resource utilization rate, and significant volume reduction, making it a technology with great application and promotion prospects among current wind turbine blade resource utilization technologies.

[0004] Currently, the pyrolysis recycling of retired wind turbine blades mostly involves crushing the blades and then pyrolyzing them, resulting in the recovery of short fibers. This pyrolysis method damages the fibers during the crushing process, leading to varying degrees of impairment in the quality and mechanical strength of the recovered short glass fibers. Therefore, designing a pyrolysis device that minimizes the loss of mechanical properties and strength in the recovered glass fibers is a pressing technical problem that needs to be solved in this field.

[0005] Therefore, a new pyrolysis recovery system and method for wind turbine blade glass fiber bundles is needed to solve the above problems. Summary of the Invention

[0006] The main objective of this invention is to provide a new pyrolysis recovery system and method for wind turbine blade glass fiber bundles, which can effectively recover glass fiber bundles, improve the recovery efficiency of wind turbine blades, and facilitate the reuse of retired wind turbine blades.

[0007] To achieve the above objectives, the present invention provides a pyrolysis recovery system for glass fiber bundles in wind turbine blades, comprising a feeding device, a pyrolysis reactor, a conveying device, and an oxidation reactor arranged transversely in sequence. The pyrolysis recovery system further includes a flue gas purification system, a first heat exchanger, a second heat exchanger, a pyrolysis oil recovery system, and a burner; wherein:

[0008] The feeding device includes a conveyor belt;

[0009] The pyrolysis reactor includes a first shell and a first conveyor chain plate disposed on the bottom surface inside the first shell. The first shell has a first feed inlet and a first discharge outlet disposed opposite to each other. The first conveyor chain plate is disposed between the first feed inlet and the first discharge outlet. The inner cavity of the first shell forms a pyrolysis chamber. A pyrolysis gas outlet is disposed above the first shell. The pyrolysis oil recovery system is connected to the pyrolysis chamber through the pyrolysis gas outlet. A first heat exchange device is disposed in the pyrolysis chamber. The first heat exchange device includes multiple longitudinally arranged first heat exchange tubes. The upper end of the first heat exchange tubes is connected to the flue gas purification system, and the lower end of the first heat exchange tubes is connected to the oxidation reactor. The first heat exchange tubes are not connected to the gas in the pyrolysis chamber.

[0010] The conveying device includes a second conveyor chain plate, the feed end of which is located below the first discharge port;

[0011] The oxidation reactor includes a third shell and a third conveyor chain plate mounted inside the third shell. The inner cavity of the third shell forms an oxidation reaction chamber. A second feed inlet is provided below the material drop end of the third shell near the second conveyor chain plate, and a second discharge outlet is provided near the material drop end of the third shell. An oxidation gas outlet is provided above the third shell and is connected to the lower opening of the first heat exchange tube. The lower part of the oxidation reaction chamber is connected to an air supply system, which provides upward airflow to the oxidation reaction chamber. A second heat exchange device is disposed above the third conveyor chain plate and includes multiple second heat exchange tubes arranged along the conveying direction of the third conveyor chain plate. Each second heat exchange tube includes an inlet and an outlet. The inlet is connected to the burner, and the outlet is directly or indirectly connected to the lower opening of the first heat exchange tube.

[0012] The pyrolysis oil recovery system includes a condenser and a pyrolysis oil collection tank connected to the condensate outlet of the condenser. The air inlet of the condenser is connected to the pyrolysis gas outlet, and the air outlet of the condenser is connected to the burner. The burner is used to burn the passing gas and deliver it to the air inlet.

[0013] Movable heat-insulating baffles are provided at the first feed inlet, the first discharge inlet, the second feed inlet, and the second discharge inlet; the conveyor belt, the first conveyor chain plate, the second conveyor chain plate, and the third conveyor chain plate have the same conveying direction in the horizontal direction.

[0014] Optionally, the first heat exchange device further includes an upper gas collecting cover and a lower gas collecting cover disposed opposite to each other. Both the upper and lower gas collecting covers are hollow plates. The bottom surface of the upper gas collecting cover has multiple upper openings corresponding to the first heat exchange tubes, and the upper opening of the first heat exchange tubes is connected to the upper openings. The top surface of the lower gas collecting cover has multiple lower openings corresponding to the first heat exchange tubes, and the lower opening of the first heat exchange tubes is connected to the lower openings. The bottom surface of the lower gas collecting cover has a first gas port communicating with the oxidation gas outlet. The upper gas collecting cover is located above the first conveyor belt, and the lower gas collecting cover is located below the first conveyor belt.

[0015] Optionally, the bottom of the first housing is further provided with a gas supply pipe, which connects the first gas port to the oxidizing gas outlet, or the gas supply pipe connects the first gas port to the oxidizing gas outlet and the gas outlet.

[0016] Optionally, the feeding device further includes a second housing, the conveyor belt is disposed inside the second housing, the second housing is provided with a third inlet and a third outlet, the third outlet is disposed directly opposite the first inlet; the height of the third inlet is lower than the height of the third outlet, and the conveyor belt includes a first horizontal conveyor belt, an inclined lifting conveyor belt and a second horizontal conveyor belt arranged in sequence laterally.

[0017] Optionally, the third discharge port is further provided with two flexible rollers with flexible material wrapped on their surfaces, which are arranged opposite each other. The wind turbine blades on the conveyor belt are guided into the pyrolysis chamber through the gap between the two flexible rollers; wherein the distance between the two flexible rollers is less than the thickness of the wind turbine blades.

[0018] Optionally, an air distribution device is provided below the third conveyor chain plate, and an air supply system is provided between the air distribution device and the bottom surface of the second housing. The air supply system includes an air compressor. The air distribution device is an air guide plate with uniform holes or multiple upward air guide wheels.

[0019] Optionally, both the first and third conveyor chains are provided with ventilation holes.

[0020] Optionally, the movable heat insulation baffle is respectively hung at the corresponding first inlet, first outlet, second inlet and second outlet via lifting transmission rope; each movable heat insulation baffle includes two heat insulation panels arranged opposite each other and a cooling pipe sandwiched between the two heat insulation panels, the cooling pipe being connected to a coolant circulation device.

[0021] Optionally, the second heat exchange device includes a plurality of heat exchange sub-tube assemblies, each of the heat exchange sub-tube assemblies including the air inlet, the second heat exchange tube arranged on a plane and bent back and forth along the conveying direction of the third conveyor chain plate, and the air outlet.

[0022] The present invention also provides a method for pyrolysis recovery of glass fiber bundles from wind turbine blades based on the pyrolysis recovery system described above, comprising the following steps:

[0023] S1, during initial startup, delivers combustible gas to the burner and, after combustion, transfers it to the second heat exchange device so that the temperature of the oxidation reaction chamber reaches 500℃-700℃ and the reaction temperature of the pyrolysis chamber reaches 400℃-600℃.

[0024] S2, the recovered wind turbine blades are fed through the feeding device, and the transmission rate of the first conveyor chain plate is controlled so that the pyrolysis time of the wind turbine blades in the pyrolysis chamber is 2-4 hours. The transmission rate of the third conveyor chain plate is controlled so that the oxidation time of the wind turbine blades in the oxidation reaction chamber is 2-4 hours. After the temperature of the pyrolysis chamber and the oxidation reaction chamber stabilizes, the supply of combustible gas to the burner is stopped.

[0025] S3, start the flue gas purification system and pyrolysis oil recovery system;

[0026] S4 controls the intermittent opening and closing of the movable heat insulation baffle, so that the wind turbine blades that have completed pyrolysis in the pyrolysis chamber fall into the oxidation reaction chamber, and the glass fibers that have completed oxidation and decarbonization are discharged through the discharge port.

[0027] The pyrolysis recovery system and method for glass fiber bundles in wind turbine blades described in this invention have at least the following advantages:

[0028] (1) Movable heat insulation baffles that can move up and down are respectively installed at the connection between the feeding device and the pyrolysis reactor, the connection between the conveying device and the pyrolysis reactor, the connection between the conveying device and the oxidation reactor, and the outlet of the recycled fiber. When the decommissioned fan blades pass by, they approach the movable heat insulation baffles through the chain plate device, and the heat insulation baffles move upward. After the fan blades pass by, they automatically close, which can minimize the heat loss of the pyrolysis chamber and maintain the inert atmosphere of the pyrolysis chamber.

[0029] (2) By setting a first heat exchange device inside the pyrolysis chamber and setting a first heat exchange tube around the first conveyor chain plate, it is beneficial to the pyrolysis of the fan blades.

[0030] (3) The high-temperature pyrolysis gas generated by the pyrolysis reaction in the pyrolysis chamber is condensed and separated into pyrolysis oil. The remaining non-condensable gas is fully burned by the burner and then introduced into the second heat exchange device in the oxidation reaction chamber to provide heat for the oxidation reaction in the oxidation reaction chamber. The heat and flue gas generated by the oxidation reaction in the oxidation reaction chamber are introduced into the first heat exchange device in the pyrolysis chamber together with the gas of the second heat exchange device to provide heat for the pyrolysis reaction. They are isolated from each other and can also be used for heat recycling, which further improves the thermal efficiency of the system.

[0031] (4) The pyrolysis recovery system for wind turbine blade glass fiber bundles can process wind turbine blades of a certain length, cut retired wind turbine blades to a specific length, and closely combine the pyrolysis and oxidation processes, resulting in glass fiber bundles with good mechanical properties.

[0032] (5) By installing flexible rollers or flexible serrated rollers, on the one hand, the flexible rollers allow the fan blades to enter the conveyor completely; on the other hand, the distance between the upper and lower flexible rollers can be set to be less than the thickness of the fan blades, which effectively reduces gas exchange and ensures an inert atmosphere between the chambers.

[0033] (6) Wide range of raw materials applicable and flexible and adjustable reaction process: By adjusting the transmission speed of the conveyor chain plate, the temperature of the flue gas generated by the burner, and the position and angle of the air distribution device and fan outside each stage of the reaction chamber in the flue, the working state of the reaction chamber can be flexibly changed to adapt to the efficient pyrolysis of retired wind turbine blades of different parts and different components.

[0034] (7) High degree of product resource utilization: In addition to recycling glass fiber, the pyrolysis gas generated by the pyrolysis of retired wind turbine blades can be used for combustion to provide heat for reactor pyrolysis and realize the self-heating pyrolysis process.

[0035] After condensation, a liquid product is obtained, which can be used as a liquid fuel or further purified to synthesize high-value chemicals;

[0036] (8) Clean emissions: All flue gas generated is treated by dust removal and purification devices before being discharged, achieving the harmless treatment of retired wind turbine blades. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0038] Figure 1This is a cross-sectional structural schematic diagram of a pyrolysis recovery system for glass fiber bundles in wind turbine blades according to an embodiment of the present invention;

[0039] Figure 2 for Figure 1 Left view of the pyrolysis recovery system in the image;

[0040] Figure 3 for Figure 1 Top view of the pyrolysis recovery system in the middle;

[0041] Figure 4 This is a partial structural schematic diagram of the heat exchange tube assembly of the second heat exchanger and the oxidation reactor provided in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of a movable heat-insulating baffle provided in an embodiment of the present invention;

[0043] Figure 6 for Figure 5 A schematic diagram of the internal structure of the movable heat insulation baffle in the middle;

[0044] Figure 7 This is a schematic diagram of the structure of a first heat exchange device provided in an embodiment of the present invention;

[0045] Figure 8 for Figure 7 A schematic diagram of the internal structure of the first heat exchanger in the diagram.

[0046] Label Explanation:

[0047] Feeding device 1, second housing 10, conveyor belt 12, first horizontal conveyor belt 121, inclined lifting conveyor belt 122, second horizontal conveyor belt 123, flexible roller shaft 13;

[0048] Movable heat insulation baffle 14, heat insulation panel 141, cooling pipe 142, lifting transmission rope 143, coolant circulation device 144, coolant inlet 1441, coolant outlet 1442;

[0049] Pyrolysis reactor 2, pyrolysis chamber 200, first heat exchange device 20, first feed inlet 201, first discharge outlet 202, first conveyor chain plate 21, third gas outlet 22, pyrolysis gas outlet 23, gas transmission pipe 24, first heat exchange pipe 25, upper opening 251, lower opening 252, first shell 26, upper gas collecting cover 721, lower gas collecting cover 722, first gas outlet 723;

[0050] Conveying device 3, second conveyor chain plate 31;

[0051] Oxidation reactor 4, oxidation reaction chamber 400, second heat exchange device 40, second feed inlet 401, second discharge outlet 402, third conveyor chain plate 41, second heat exchange tube 42, air inlet 43, oxidation gas outlet 44, air distribution device 45, air outlet 46, hole 451;

[0052] Air supply system 5;

[0053] 6. Air extraction device;

[0054] 7. Pyrolysis oil recovery system; 71. Condenser; 72. Pyrolysis oil collection box; 73. Pyrolysis gas pipeline;

[0055] Burner 8;

[0056] 9. Flue gas purification system; 91. Flue gas purifier; 92. Dust collector.

[0057] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0058] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0059] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this embodiment are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicator will also change accordingly.

[0060] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0063] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0064] Please combine Figure 1 As shown, the pyrolysis recovery system provided by the present invention includes a feeding device 1, a pyrolysis reactor 2, a conveying device 3 and an oxidation reactor 4 arranged in sequence in a horizontal direction. The pyrolysis recovery device also includes a flue gas purification system 9, a first heat exchange device 20, a second heat exchange device 40, a pyrolysis oil recovery system 7 and a burner 8.

[0065] The feeding device 1 includes a conveyor belt 12.

[0066] In this embodiment, the conveyor belt 12 is used to transport wind turbine blades cut to a suitable length from a low position to a high position; alternatively, the conveyor belt 12 can also be used for horizontal transport, and the cut wind turbine blades can be transported by other hoisting or lifting mechanisms.

[0067] The pyrolysis reactor 2 includes a first shell 26 and a first conveyor chain plate 21 disposed on the bottom surface inside the first shell 26. The first shell 26 has a first feed inlet 201 and a first discharge outlet 202 disposed opposite to each other. The first conveyor chain plate 21 is disposed between the first feed inlet 201 and the first discharge outlet 202. The inner cavity of the first shell 26 forms a pyrolysis chamber 200. A pyrolysis gas outlet 23 is provided above the first shell. The pyrolysis oil recovery system 7 is connected to the pyrolysis chamber 200 through the pyrolysis gas outlet 23.

[0068] Furthermore, in a preferred embodiment, the pyrolysis oil recovery system 7 can be located on one side of the pyrolysis reactor 2, and the pyrolysis gas outlet 23 is connected to the pyrolysis oil recovery system 7 via a pyrolysis gas pipeline 73. The number of pyrolysis gas outlets 23 can be one or more.

[0069] Those skilled in the art can also, as needed, appropriately install an exhaust fan on the pyrolysis gas pipeline to provide the suction pressure for the pyrolysis gas to flow from the pyrolysis chamber 200 to the pyrolysis oil recovery system 7, which will not be elaborated here. Furthermore, in other parts of this embodiment, blower and exhaust devices can be installed as needed to provide the necessary pneumatic power for the gas circulation of the entire pyrolysis recovery system. The specific embodiments mainly describe the technical features that address the technical problem actually intended to be solved by this invention. Contents related to the pyrolysis recovery system that overlap with existing technologies and can be selected by those skilled in the art as needed are not elaborated upon; however, this does not mean that the technical solution of the pyrolysis recovery system in this invention is incomplete.

[0070] The first heat exchange device 20 is disposed in the pyrolysis chamber 200. The first heat exchange device 20 includes multiple longitudinally arranged first heat exchange tubes 25. The upper opening 251 of the first heat exchange tubes 25 is connected to the flue gas purification system 9, and the lower opening 252 of the first heat exchange tubes 25 is connected to the oxidation reactor 4. The first heat exchange tubes 25 are not in communication with the gas in the pyrolysis chamber 200.

[0071] Optionally, the first heat exchange tube 25 is arranged around the first conveyor chain plate 21.

[0072] Furthermore, in a specific example, the upper opening 251 of the first heat exchange tube 25 can be connected to the flue gas purification system 9 set outside the pyrolysis reactor 2 through a pipe, only needing to ensure the overall airtightness of the pyrolysis chamber 200.

[0073] The conveying device 3 includes a second conveyor chain plate 31, the feed end of which is located below the first discharge port 201.

[0074] In one specific example, the conveying direction of the second conveyor chain 31 may be slightly downward along the conveying direction. In other embodiments, the conveying direction of the second conveyor chain 31 may also be horizontal.

[0075] The oxidation reactor 4 includes a third shell 47 and a third conveyor chain plate 41 disposed within the third shell 47. The inner cavity of the third shell 47 forms an oxidation reaction chamber 400. A second feed inlet 401 is provided below the material drop end of the third shell 47 near the material drop end of the second conveyor chain plate 31. A second discharge outlet 402 is provided near the material drop end of the third shell 47 near the material drop end of the third conveyor chain plate 41. An oxidation gas outlet 44 is provided above the third shell 47 and is connected to the lower opening of the first heat exchange tube 25. The lower part of the oxidation reaction chamber 400 is connected to an air supply system 5, which provides upward airflow to the oxidation reaction chamber 400.

[0076] The second heat exchange device 40 is disposed above the third conveyor chain plate 41. The second heat exchange device 40 includes a plurality of second heat exchange tubes 42 arranged along the conveying direction of the third conveyor chain plate 41. The second heat exchange tube 42 includes an air inlet 43 and an air outlet 46. The air inlet 43 is connected to the burner 8, and the air outlet 46 is directly or indirectly connected to the lower end of the first heat exchange tube 25.

[0077] The gas discharged from the second heat exchange tube 42 through the outlet 46 can be connected to the first heat exchange tube 25 through a separate pipe; it can also be discharged directly into the oxidation reaction chamber 400 and flow together with the flue gas after the oxidation reaction into the first heat exchange tube 25; or it can be discharged directly into the flue gas purification system 9.

[0078] The pyrolysis oil recovery system 7 includes a condenser 71 and a pyrolysis oil collection tank 72 connected to the condensate outlet of the condenser 71. The air inlet of the condenser 71 is connected to the pyrolysis gas outlet 23 by the action of the air extraction device 6, and the air outlet of the condenser 71 is connected to the burner 8.

[0079] The burner 8 is used to burn the passing gas and deliver it to the inlet 43 of the second heat exchange tube 42.

[0080] Movable heat-insulating baffles 14 are provided at the first feed inlet 201, the first discharge outlet 202, the second feed inlet 401, and the second discharge outlet 402; the conveyor belt 12, the first conveyor chain plate 21, the second conveyor chain plate 31, and the third conveyor chain plate 41 have the same conveying direction in the horizontal direction.

[0081] During initial startup, combustible gas is supplied to the burner 8 to provide initial heat to the overall pyrolysis recovery system. After the pyrolysis reaction begins, the pyrolysis gas enters the condenser 71 (which can be a shell-and-tube heat exchanger) through the pyrolysis gas channel for condensation, thereby separating into pyrolysis oil and non-condensable gas. The non-condensable gas typically includes combustible gases such as hydrogen and methane. No additional fuel supply is required afterward, and the pyrolysis reaction can continuously maintain the pyrolysis energy and oxidation reaction energy required by the pyrolysis recovery system.

[0082] Specifically, the high-temperature flue gas from combustion, delivered by burner 8, undergoes heat exchange in oxidation reaction chamber 400 via second heat exchange tube 42, raising the reaction temperature in oxidation reaction chamber 400 to 500℃-700℃. Powered by the air supply system 5, the pyrolyzed solid material on third conveyor chain plate 41 comes into full contact with oxygen at high temperature, undergoing oxidation and decarbonization, leaving behind glass fiber bundles. The high-temperature reaction flue gas from oxidation reaction chamber 400 is then transported by airflow through oxidation gas outlet 44 into first heat exchange tube 25. First heat exchange tube 25 exchanges heat with pyrolysis chamber 200, raising the temperature in pyrolysis chamber 200 to 400℃-600℃. The wind turbine blades on first conveyor chain plate 21 undergo pyrolysis, and the pyrolyzed solid material enters oxidation reaction chamber 400 via conveyor device 3, while pyrolysis gas is discharged to pyrolysis oil recovery system 7.

[0083] The working principle of the pyrolysis recovery system is explained below through a specific workflow.

[0084] First, during initial startup, combustible gas is supplied to the burner 8, generating high-temperature flue gas of 800℃-1000℃. This flue gas enters the second heat exchange tube 42 of the second heat exchange device 40 through the inlet 43, and then heats the oxidation reaction chamber 400 of the oxidation reactor 4 through heat exchange. By adjusting the burner 8 and the air supply system 5, the high-temperature flue gas in the oxidation reaction chamber 400 is transported by the wind through the oxidation gas outlet 44 into the first heat exchange tube 25. The first heat exchange tube 25 exchanges heat with the pyrolysis chamber 200, raising the temperature of the pyrolysis chamber 200 to 400℃-600℃. Then, the cut wind turbine blades are fed into the feed device 1 at a suitable feed rate. The first conveyor chain 21 moves at a uniform speed according to the designed speed, and the decommissioned wind turbine blades are uniformly heated and decomposed in the pyrolysis chamber 200. The generated pyrolysis gas enters the condenser through the pyrolysis gas channel 23. The pyrolysis reactor 71 separates the decomposing wind turbine blades into pyrolysis oil and non-condensable gas. After passing through the pyrolysis reactor 2, the decomposed wind turbine blades are discharged through the opening of the movable heat insulation baffle 14, falling onto the second conveyor chain plate 31 via the first discharge port 201 and then onto the third conveyor chain plate 41. They are then oxidized and decarbonized in the oxidation reaction chamber 400 under aerobic conditions. The high-temperature gas generated after oxidation is exchanged through the first heat exchange tube 25 to help maintain the temperature of the pyrolysis chamber 200. After the decomposed wind turbine blades are completely oxidized in the oxidation reaction chamber, the remaining recycled glass fiber bundles are discharged through the second discharge port 402 to the external solid collection device. In addition, the non-condensable gas obtained after pyrolysis separation is used as fuel gas and fed into the burner 8 for combustion and heating to continuously generate high-temperature flue gas to heat the second heat exchange device 40, thereby maintaining the temperature of the pyrolysis and oxidation reactions required by the pyrolysis recovery system.

[0085] Specifically, in a preferred embodiment, the feeding device 1 can be a closed structure, for example, it may also include a second housing 10, the conveyor belt 12 is disposed inside the second housing 10, the second housing 10 is provided with a third inlet and a third outlet, the third outlet is disposed directly opposite the first inlet; the height of the third inlet is lower than the height of the third outlet, and the conveyor belt 12 includes a first horizontal conveyor belt 121, an inclined lifting conveyor belt 122 and a second horizontal conveyor belt 123 arranged in sequence laterally.

[0086] The third discharge port is also equipped with two flexible rollers 13, each with a flexible material covering its surface, arranged vertically opposite each other. The wind turbine blades on the conveyor belt 12 are guided into the pyrolysis chamber 200 through the gap between the two flexible rollers 13. The gap between the two flexible rollers 13 is less than the thickness of the wind turbine blade. The two flexible rollers 13, arranged vertically from top to bottom, allow the wind turbine blades to enter the pyrolysis chamber 200 completely. The gap between the two flexible rollers 13 can be set to be less than the thickness of the wind turbine blades to be recycled, such as 0.5-1 times. The two flexible rollers 13 can effectively reduce the entry of outside air into the pyrolysis chamber, which is beneficial for maintaining the inert atmosphere inside the pyrolysis chamber 200.

[0087] Meanwhile, the sizes of the pyrolysis reactor 2 and the oxidation reactor 4 can be set as needed. The main reference quantities for the design can be calculated based on the length of the maximum processable fiber bundle, their respective reaction temperatures, and the transmission rates of each conveyor chain plate. The two can be designed to be similar in size or to have different sizes.

[0088] Optionally, in this embodiment, the flue gas purification system 9 includes a dust collector 92 and a flue gas purifier 91; wherein, the flue gas purifier can be selected and configured as needed by those skilled in the art, for example, according to the proportion of nitrogen and sulfur in the flue gas, as well as the proportion of other harmful components such as carbon dioxide, such as selecting a denitrification device.

[0089] Optionally, in this embodiment, an air distribution device 45 is provided below the third conveyor chain plate 41, and an air supply system 5 is provided between the air distribution device 45 and the bottom surface of the third housing 47. The air supply system 5 may include an air compressor. In this embodiment, the air distribution device 45 is an air guide plate with uniformly spaced holes 451. In other embodiments, the air distribution device 45 may also be multiple upward-directing air guide wheels, etc.

[0090] Please combine them together Figure 7 and Figure 8Optionally, in this embodiment, the first heat exchange device 20 further includes an upper gas collecting cover 721 and a lower gas collecting cover 722 disposed opposite to each other. Both the upper gas collecting cover 721 and the lower gas collecting cover 722 are hollow plates. The bottom surface of the upper gas collecting cover 721 has a plurality of upper openings corresponding to the first heat exchange tube 25. The upper opening 251 of the first heat exchange tube 25 is connected to the upper opening (e.g., by welding). The top surface of the lower gas collecting cover 722 has a plurality of lower openings corresponding to the first heat exchange tube 25. The lower opening 252 of the first heat exchange tube 25 is connected to the lower opening (e.g., by welding). The bottom surface of the lower gas collecting cover 722 has a first gas port 723 communicating with the oxidation gas outlet 44. The upper gas collecting cover 721 also has a third gas port 22 communicating with the flue gas purification system 3.

[0091] Correspondingly, a gas supply pipe 24 is also provided at the bottom of the first housing 26. The gas supply pipe 24 connects the first gas port 723 and the oxidizing gas outlet 44, or the gas supply pipe 24 connects the first gas port 723 to both the oxidizing gas outlet 44 and the gas outlet 46.

[0092] The upper gas collecting cover 721 is located above the first conveyor chain plate 21, and the lower gas collecting cover 722 is located below the first conveyor chain plate 21. Optionally, the lower gas collecting cover 722 is located below the bottom plate of the first housing 26 below the first conveyor chain plate 21, or the top surface of the lower gas collecting cover 722 is shared as the bottom surface of the first housing 26.

[0093] Optionally, please combine them together. Figure 6 In this embodiment, both the first conveyor chain plate 21 and the third conveyor chain plate 41 are chain plate type conveying devices, and ventilation holes (not shown in the figure) are provided on the conveyor chain plates.

[0094] Alternatively, as a preferred embodiment of the chain plate, the conveying surfaces of the first conveyor chain plate 21 and the third conveyor chain plate 41 in the above embodiments are arranged horizontally.

[0095] Optionally, in this embodiment, the second heat exchange device 40 includes a plurality of heat exchange sub-tube assemblies, each of the heat exchange sub-tube assemblies including the air inlet 43, the second heat exchange tube 42 which is arranged on a plane and bends back and forth along the conveying direction of the third conveyor chain plate, and the air outlet 46.

[0096] Optionally, in a specific example, the movable heat insulation baffle 14 can be suspended by a lifting transmission rope 143 at the corresponding first feed inlet 201, first discharge outlet 202, second feed inlet 401, and second discharge outlet 402 respectively; each movable heat insulation baffle 14 includes two heat insulation panels 141 arranged opposite to each other and a cooling pipe 142 sandwiched between the two heat insulation panels. The cooling pipe 142 is connected to a coolant circulation device 144, and the coolant circulation device 144 is connected to the cooling pipe 142 through a coolant inlet 1441 and a coolant outlet 1442 to circulate the coolant.

[0097] It is understandable that the structure of the movable heat insulation baffle 14 can also be in other ways, such as by using two compartment doors set at the top and bottom, which can also achieve a certain degree of sealing and material conveying.

[0098] The present invention also provides a method for pyrolysis recovery of glass fiber bundles from wind turbine blades based on the pyrolysis recovery system described above, comprising the following steps:

[0099] S1, during initial startup, delivers combustible gas to the burner and, after combustion, transfers it to the second heat exchange device so that the temperature of the oxidation reaction chamber reaches 500℃-700℃ and the reaction temperature of the pyrolysis chamber reaches 400℃-600℃.

[0100] S2, the recovered wind turbine blades are fed through the feeding device, and the transmission rate of the first conveyor chain plate is controlled so that the pyrolysis time of the wind turbine blades in the pyrolysis chamber is 2-4 hours. The transmission rate of the third conveyor chain plate is controlled so that the oxidation time of the wind turbine blades in the oxidation reaction chamber is 2-4 hours. After the temperature of the pyrolysis chamber and the oxidation reaction chamber stabilizes, the supply of combustible gas to the burner is stopped.

[0101] S3, start the flue gas purification system and pyrolysis oil recovery system;

[0102] S4 controls the opening and closing of the movable heat insulation baffle so that the wind turbine blades that have completed pyrolysis in the pyrolysis chamber fall into the oxidation reaction chamber, and the glass fibers that have completed oxidation and decarbonization are discharged through the outlet.

[0103] Specifically, during initial startup, combustible gas is supplied to the burner 8, generating high-temperature flue gas of 800℃-1000℃. This flue gas enters the second heat exchange tube 42 of the second heat exchange device 40 through the inlet 43, and then heats the oxidation reaction chamber 400 of the oxidation reactor 4 through heat exchange. By adjusting the burner 8 and the air supply system 5, the high-temperature flue gas in the oxidation reaction chamber 400 is transported by the airflow through the oxidant outlet 44 into the first heat exchange tube 25. The first heat exchange tube 25 then connects with the pyrolysis chamber 200. Heat exchange is performed to raise the temperature of the pyrolysis chamber 400 to 400℃-600℃; the flue gas purification system 9 and the pyrolysis oil recovery system 7 are activated; then, the cut wind turbine blades are fed into the pyrolysis chamber 200 through the feeding device 1 at a suitable feeding rate; the first conveyor chain plate 21 moves at a uniform speed according to the design, and the transmission rate of the first conveyor chain plate 21 is controlled so that the pyrolysis time of the wind turbine blades in the pyrolysis chamber 200 is 2-4 hours. The decommissioned wind turbine blades are uniformly heated and decomposed in the pyrolysis chamber 200, and the generated pyrolysis gas is decomposed by the pyrolysis... Gas enters the condenser 71 through the gas channel 23, where it is separated into pyrolysis oil and non-condensable gas. After passing through the pyrolysis reactor 2, the decommissioned wind turbine blades, after pyrolysis, fall through the first discharge port 202 onto the second conveyor chain plate 31 and are then conveyed to the third conveyor chain plate 41 via the opening of the movable heat insulation baffle 14. There, they undergo oxidation and decarbonization under aerobic conditions in the oxidation reaction chamber 400. By controlling the transmission rate of the third conveyor chain plate 41, the oxidation time of the wind turbine blades in the oxidation reaction chamber 400 is set to 2-4 hours. The generated high-temperature gas undergoes heat exchange through the second heat exchange tube 25 to help maintain the temperature of the pyrolysis chamber 200. After the decommissioned wind turbine blades are completely oxidized in the oxidation reaction chamber 400, the remaining recycled glass fiber bundles are discharged to the external solid collection device through the second discharge port 402. In addition, the non-condensable gas obtained after pyrolysis separation is used as fuel gas and fed into the burner 8 for combustion and heating to continuously generate high-temperature flue gas to heat the second heat exchange device 40 and maintain the temperature of the pyrolysis and oxidation reactions required by the pyrolysis recovery system.

[0104] The pyrolysis recovery system and method for glass fiber bundles in wind turbine blades described in this invention have at least the following advantages:

[0105] (1) Movable heat insulation baffles that can move up and down are respectively installed at the connection between the feeding device and the pyrolysis reactor, the connection between the conveying device and the pyrolysis reactor, the connection between the conveying device and the oxidation reactor, and the outlet of the recycled fiber. When the decommissioned fan blades pass by, they approach the movable heat insulation baffles through the chain plate device, and the heat insulation baffles move upward. After the fan blades pass by, they automatically close, which can minimize the heat loss of the pyrolysis chamber and maintain the inert atmosphere of the pyrolysis chamber.

[0106] (2) By setting a first heat exchange device inside the pyrolysis chamber and setting a first heat exchange tube around the first conveyor chain plate, it is beneficial to the pyrolysis of the fan blades.

[0107] (3) The high-temperature pyrolysis gas generated by the pyrolysis reaction in the pyrolysis chamber is condensed and separated into pyrolysis oil. The remaining non-condensable gas is fully burned by the burner and then introduced into the second heat exchange device in the oxidation reaction chamber to provide heat for the oxidation reaction in the oxidation reaction chamber. The heat and flue gas generated by the oxidation reaction in the oxidation reaction chamber are introduced into the first heat exchange device in the pyrolysis chamber together with the gas of the second heat exchange device to provide heat for the pyrolysis reaction. They are isolated from each other and can also be used for heat recycling, which further improves the thermal efficiency of the system.

[0108] (4) The pyrolysis recovery system for wind turbine blade glass fiber bundles can process wind turbine blades of a certain length, cut retired wind turbine blades to a specific length, and closely combine the pyrolysis and oxidation processes, resulting in glass fiber bundles with good mechanical properties.

[0109] (5) By installing flexible rollers or flexible serrated rollers, on the one hand, the flexible rollers allow the fan blades to enter the conveyor completely; on the other hand, the distance between the upper and lower flexible rollers can be set to be less than the thickness of the fan blades, which effectively reduces gas exchange and ensures an inert atmosphere between the chambers.

[0110] (6) Wide range of raw materials applicable and flexible and adjustable reaction process: By adjusting the transmission speed of the conveyor chain plate, the temperature of the flue gas generated by the burner, and the position and angle of the air distribution device and fan outside each stage of the reaction chamber in the flue, the working state of the reaction chamber can be flexibly changed to adapt to the efficient pyrolysis of retired wind turbine blades of different parts and different components.

[0111] (7) High degree of product resource utilization: In addition to recycling glass fiber, the pyrolysis gas generated by the pyrolysis of retired wind turbine blades can be used for combustion to provide heat for reactor pyrolysis and realize the self-heating pyrolysis process; after condensation, liquid products are obtained, which can be used as liquid fuel or further purified to synthesize high-value chemicals;

[0112] (8) Clean emissions: All flue gas generated is treated by dust removal and purification devices before being discharged, achieving the harmless treatment of retired wind turbine blades.

[0113] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A pyrolysis recovery system for glass fiber bundles in wind turbine blades, characterized in that, The system includes a feeding device, a pyrolysis reactor, a conveying device, and an oxidation reactor arranged horizontally in sequence. The pyrolysis recovery system also includes a flue gas purification system, a first heat exchanger, a second heat exchanger, a pyrolysis oil recovery system, and a burner; wherein: The feeding device includes a conveyor belt; The pyrolysis reactor includes a first shell and a first conveyor chain plate disposed on the bottom surface inside the first shell. The first shell has a first feed inlet and a first discharge outlet disposed opposite to each other. The first conveyor chain plate is disposed between the first feed inlet and the first discharge outlet. The inner cavity of the first shell forms a pyrolysis chamber. A pyrolysis gas outlet is disposed above the first shell. The pyrolysis oil recovery system is connected to the pyrolysis chamber through the pyrolysis gas outlet. A first heat exchange device is disposed in the pyrolysis chamber. The first heat exchange device includes multiple longitudinally arranged first heat exchange tubes. The upper end of the first heat exchange tubes is connected to the flue gas purification system, and the lower end of the first heat exchange tubes is connected to the oxidation reactor. The first heat exchange tubes are not connected to the gas in the pyrolysis chamber. The conveying device includes a second conveyor chain plate, the feed end of which is located below the first discharge port; The oxidation reactor includes a third shell and a third conveyor chain plate mounted inside the third shell. The inner cavity of the third shell forms an oxidation reaction chamber. A second feed inlet is provided below the material drop end of the third shell near the second conveyor chain plate, and a second discharge outlet is provided near the material drop end of the third shell. An oxidation gas outlet is provided above the third shell and is connected to the lower opening of the first heat exchange tube. The lower part of the oxidation reaction chamber is connected to an air supply system, which provides upward airflow to the oxidation reaction chamber. A second heat exchange device is disposed above the third conveyor chain plate and includes multiple second heat exchange tubes arranged along the conveying direction of the third conveyor chain plate. Each second heat exchange tube includes an inlet and an outlet. The inlet is connected to the burner, and the outlet is directly or indirectly connected to the lower opening of the first heat exchange tube. The pyrolysis oil recovery system includes a condenser and a pyrolysis oil collection tank connected to the condensate outlet of the condenser. The air inlet of the condenser is connected to the pyrolysis gas outlet, and the air outlet of the condenser is connected to the burner. The burner is used to burn the passing gas and deliver it to the air inlet. Movable heat insulation baffles are provided at the first feed inlet, the first discharge inlet, the second feed inlet, and the second discharge inlet. Each movable heat insulation baffle includes two heat insulation panels arranged opposite each other and a cooling pipe sandwiched between the two heat insulation panels. The cooling pipe is connected to a coolant circulation device, which is connected to the cooling pipe through a coolant inlet and a coolant outlet to circulate the coolant. The conveyor belt, the first conveyor chain plate, the second conveyor chain plate, and the third conveyor chain plate all have the same horizontal conveying direction. The bottom of the first housing is also provided with a gas supply pipe, which connects the lower end of the first heat exchange tube to the oxidizing gas outlet; An air distribution device is provided below the third conveyor chain plate, and the air supply system is located between the air distribution device and the bottom surface of the third housing. The air supply system includes an air compressor. The air distribution device is an air guide plate with uniform holes or multiple upward air guide wheels. During initial startup, combustible gas is supplied to the burner, generating high-temperature flue gas of 800ºC-1000ºC. This flue gas enters the second heat exchange tube of the second heat exchange device through the inlet, and then heats the oxidation reaction chamber of the oxidation reactor through heat exchange. By adjusting the burner and the air supply system, the high-temperature flue gas in the oxidation reaction chamber is transported by wind through the oxidation gas outlet into the first heat exchange tube. The first heat exchange tube exchanges heat with the pyrolysis chamber, raising the temperature of the pyrolysis chamber to 400ºC-600ºC. The flue gas purification system and the pyrolysis oil recovery system are then activated. Cut wind turbine blades are then fed at a suitable feeding rate through the feeding device. The first conveyor... The conveyor belt moves at a uniform speed according to the design, and the transmission speed of the first conveyor belt is controlled to ensure that the pyrolysis time of the wind turbine blades in the pyrolysis chamber is 2-4 hours. The decommissioned wind turbine blades are uniformly heated and decomposed in the pyrolysis chamber, and the generated pyrolysis gas enters the condenser through the pyrolysis gas channel, thereby separating into pyrolysis oil and non-condensable gas. After passing through the pyrolysis reactor, the pyrolyzed decommissioned wind turbine blades fall onto the second conveyor belt through the opening of the movable heat-insulating baffle via the first discharge port and are then conveyed to the third conveyor belt. There, they undergo oxidation and decarbonization under aerobic conditions in the oxidation reaction chamber. The oxidation time of the wind turbine blades in the oxidation reaction chamber is controlled by the transmission speed of the third conveyor belt to ensure that the oxidation time is 2-4 hours. h, the high-temperature gas generated after oxidation is heat-exchanged through the second heat exchange tube to help maintain the temperature of the pyrolysis chamber; after the decommissioned wind turbine blades are completely oxidized in the oxidation reaction chamber, the remaining recycled glass fiber bundles are discharged to the external solid collection device through the second discharge port; in addition, the non-condensable gas obtained after pyrolysis separation is used as fuel gas and fed into the burner for combustion and heating to continuously generate high-temperature flue gas to heat the second heat exchange device and maintain the temperature of the pyrolysis and oxidation reaction required by the pyrolysis recovery system.

2. The pyrolysis recovery system according to claim 1, characterized in that, The first heat exchange device further includes an upper gas collecting cover and a lower gas collecting cover arranged opposite to each other. Both the upper and lower gas collecting covers are hollow plates. The bottom surface of the upper gas collecting cover has multiple upper openings corresponding to the first heat exchange tubes, and the upper opening of the first heat exchange tubes is connected to the upper openings. The top surface of the lower gas collecting cover has multiple lower openings corresponding to the first heat exchange tubes, and the lower opening of the first heat exchange tubes is connected to the lower openings. The bottom surface of the lower gas collecting cover has a first gas port communicating with the oxidation gas outlet. The upper gas collecting cover is located above the first conveyor chain plate, and the lower gas collecting cover is located below the first conveyor chain plate.

3. The pyrolysis recovery system according to claim 2, characterized in that, The gas supply pipe connects the first gas inlet to the oxidizing gas outlet, or the gas supply pipe connects the first gas inlet to the oxidizing gas outlet and the gas outlet.

4. The pyrolysis recovery system according to claim 1, characterized in that, The feeding device further includes a second housing, and the conveyor belt is disposed inside the second housing. The second housing is provided with a third inlet and a third outlet, and the third outlet is disposed directly opposite the first inlet. The height of the third inlet is lower than the height of the third outlet. The conveyor belt includes a first horizontal conveyor belt, an inclined lifting conveyor belt, and a second horizontal conveyor belt arranged in sequence.

5. The pyrolysis recovery system according to claim 4, characterized in that, The third discharge port is also provided with two flexible rollers with flexible material on their surfaces, which are arranged opposite each other. The wind turbine blades on the conveyor belt are guided into the pyrolysis chamber through the gap between the two flexible rollers. The distance between the two flexible rollers is less than the thickness of the wind turbine blades.

6. The pyrolysis recovery system according to claim 1, characterized in that, Both the first and third conveyor chains have ventilation holes.

7. The pyrolysis recovery system according to claim 1, characterized in that, The movable heat insulation baffles are respectively hung at the first feed inlet, the first discharge inlet, the second feed inlet, and the second discharge outlet via lifting transmission ropes.

8. The pyrolysis recovery system according to claim 1, characterized in that, The second heat exchange device includes multiple heat exchange sub-tube assemblies, each of which includes the air inlet, a second heat exchange tube arranged on a plane and bent back and forth along the conveying direction of the third conveyor chain plate, and the air outlet.

9. A method for pyrolysis recovery of glass fiber bundles from wind turbine blades based on a pyrolysis recovery system as described in any one of claims 1-8, characterized in that, Including the following steps: S1, during initial startup, delivers combustible gas to the burner and, after combustion, transfers it to the second heat exchange device so that the temperature of the oxidation reaction chamber reaches 500ºC-700ºC and the reaction temperature of the pyrolysis chamber reaches 400ºC-600ºC. S2, the recovered wind turbine blades are fed through the feeding device, and the transmission rate of the first conveyor chain plate is controlled so that the pyrolysis time of the wind turbine blades in the pyrolysis chamber is 2-4 hours. The transmission rate of the third conveyor chain plate is controlled so that the oxidation time of the wind turbine blades in the oxidation reaction chamber is 2-4 hours. After the temperature of the pyrolysis chamber and the oxidation reaction chamber stabilizes, the supply of combustible gas to the burner is stopped. S3, start the flue gas purification system and pyrolysis oil recovery system; S4 controls the intermittent opening and closing of the movable heat insulation baffle, so that the wind turbine blades that have completed pyrolysis in the pyrolysis chamber fall into the oxidation reaction chamber, and the glass fibers that have completed oxidation and decarbonization are discharged through the discharge port.

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