System and method for preparing glass fibers from fan blades

Abstract

The invention provides a system and method for preparing glass fibers through fan blades, the system comprises a pretreatment unit, a pyrolysis unit, an oxidation unit, a purification unit and a heat exchanger, the pretreatment unit is suitable for crushing the fan blades into fragments of 5-10 cm and screening out impurities; the pyrolysis unit is connected with the pretreatment unit to pyrolyze the fragments; the oxidation unit is connected with the pyrolysis unit and is used for carrying out oxidation treatment on the pyrolyzed fragments and removing residual carbon on the surface; the purification unit is respectively connected with an exhaust port of the pyrolysis unit and an exhaust port of the oxidation unit so as to purify pyrolysis gas generated by pyrolysis and flue gas generated by oxidation and then discharge the purified pyrolysis gas and flue gas; the heat exchanger is connected with an exhaust port of the purification unit so as to recover heat of purified waste gas. According to the invention, the resin on the surface of the glass fiber can be effectively removed, the high-strength retention rate of the glass fiber is maintained, the energy consumption is reduced, and continuous and environment-friendly production is realized.

Description

Technical Field

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

[0002] With the rapid development of the wind power industry, early-installed wind turbines are gradually entering their decommissioning period. Wind turbine blades are primarily made of glass fiber reinforced polymer (GFRP) composites, which include a thermosetting resin matrix (such as epoxy resin or unsaturated polyester resin) and glass fiber reinforcement. These composite materials have high chemical stability and are difficult to degrade naturally, posing a significant challenge to recycling and disposal.

[0003] Currently, the main methods for treating wind turbine blades include landfill, incineration, physical pulverization, and thermochemical recovery. Among these, pyrolysis technology has become a research hotspot due to its ability to separate resin from fibers. However, existing pyrolysis technologies still have many limitations, such as:

[0004] (1) Excessive pyrolysis temperature: Traditional pyrolysis is usually carried out at temperatures above 850℃, which leads to severe loss of glass fiber strength (tensile strength retention rate is only 50-60%), resulting in low quality of recycled fibers and difficulty in achieving high-value utilization.

[0005] (2) Incomplete resin removal: Although low-temperature pyrolysis reduces fiber damage, it can easily lead to incomplete resin decomposition, resulting in carbon deposits on the surface, which requires secondary treatment and increases energy consumption and cost.

[0006] (3) High energy consumption and low efficiency: The pyrolysis process requires continuous heating, which consumes a lot of energy. Although there is a waste heat recovery design, the overall economic efficiency is still not ideal.

[0007] (4) Secondary pollution problem: The pyrolysis gas produced by pyrolysis has a complex composition and contains harmful substances such as brominated flame retardants. Improper handling can easily cause environmental pollution.

[0008] (5) Low degree of continuity: Most devices operate intermittently, resulting in low processing efficiency and difficulty in meeting the needs of large-scale blade processing. Summary of the Invention

[0009] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention provide a system and method for preparing glass fibers for wind turbine blades, which can reduce energy consumption and improve the quality of recycled glass fibers.

[0010] One embodiment of the present invention provides a system for preparing glass fiber from wind turbine blades, comprising: a pretreatment unit, a pyrolysis unit, an oxidation unit, a purification unit, and a heat exchanger. The pretreatment unit is adapted to crush the wind turbine blades into fragments of 5-10 cm and screen out impurities. The pyrolysis unit is connected to the pretreatment unit to pyrolyze the fragments. The oxidation unit is connected to the pyrolysis unit to oxidize the pyrolyzed fragments to remove residual carbon from the surface. An openable gate is connected between the outlet of the pyrolysis unit and the inlet of the oxidation unit. The purification unit is connected to the exhaust ports of the pyrolysis unit and the oxidation unit respectively to purify the pyrolysis gas generated by pyrolysis and the flue gas generated by oxidation before discharge. The heat exchanger is connected to the exhaust port of the purification unit to recover heat from the purified waste gas.

[0011] In some embodiments, the pretreatment unit includes a cutter, a biaxial shear crusher, and a vibrating screen. The cutter is used to cut the fan blades into blocks, the biaxial shear crusher is used to crush the block fan blades into fragments, and the vibrating screen is used to remove impurities from the fragments.

[0012] In some embodiments, the pyrolysis unit includes a pyrolysis furnace having an inert gas inlet connected to a gas source via an inert gas pipeline connected to a heat exchanger, wherein the heat recovered by the heat exchanger preheats the inert gas.

[0013] In some embodiments, inert gas protection devices are connected to the feed inlet and discharge outlet of the pyrolysis furnace to prevent damage to the inert atmosphere inside the pyrolysis furnace.

[0014] In some embodiments, the purification unit includes a multi-stage condenser and an activated carbon adsorption device. The multi-stage condenser is used to condense and recover the oil in the pyrolysis gas, and the activated carbon adsorption device is used to adsorb the dust in the pyrolysis gas and flue gas.

[0015] In some embodiments, the pyrolysis furnace is a low-temperature pyrolysis furnace with a heating temperature below 600°C.

[0016] In some embodiments, the oxidation unit includes an oxidation furnace and a gas distributor, the gas distributor being disposed inside the furnace cavity of the oxidation furnace and connected to the gas inlet of the oxidation furnace.

[0017] Another embodiment of the present invention provides a method for preparing glass fibers for wind turbine blades, which utilizes the above-mentioned system for preparing glass fibers for wind turbine blades and includes the following steps:

[0018] S1. The pretreatment unit is used to break the fan blades into fragments with a side length of 5-10cm and remove impurities.

[0019] S2. The fragments are fed into the pyrolysis unit and heated to 400-600°C under an inert atmosphere to pyrolyze the fragments, obtaining pyrolysis products and oil and gas. The oil and gas are then fed into the purification unit to remove pollutants and recover chemicals.

[0020] S3. The pyrolysis products are passed into the oxidation unit and heated to 300-500°C in an oxygen atmosphere to oxidize the pyrolysis products, remove residual carbon on the surface, and obtain glass fiber and flue gas. The flue gas is then passed into the purification unit to remove pollutants and recover chemicals, and then discharged into the atmosphere.

[0021] In some embodiments, in step S2, the pyrolysis time is 30-60 min and the oxidation time is 20-40 min.

[0022] In some embodiments, in step S3, the exhaust gas discharged from the purification unit preheats the inert gas introduced into the pyrolysis unit. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings.

[0024] in:

[0025] Figure 1 This is a schematic diagram of the system for preparing glass fibers for wind turbine blades according to an embodiment of the present invention;

[0026] Figure label:

[0027] 1. Pretreatment unit; 2. Pyrolysis unit; 3. Oxidation unit; 4. Purification unit; 5. Heat exchanger. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] The system and method for preparing glass fiber for wind turbine blades according to embodiments of the present invention are described below with reference to the accompanying drawings.

[0030] like Figure 1As shown, one embodiment of the present invention proposes a system for preparing glass fiber from wind turbine blades, comprising: a pretreatment unit 1, a pyrolysis unit 2, an oxidation unit 3, a purification unit 4, and a heat exchanger 5. The pretreatment unit 1 is adapted to crush the wind turbine blades into fragments of 5-10 cm and screen out impurities; the pyrolysis unit 2 is connected to the pretreatment unit 1 to pyrolyze the fragments; the oxidation unit 3 is connected to the pyrolysis unit 2 to oxidize the pyrolyzed fragments to remove surface carbon residue; an openable gate is connected between the outlet of the pyrolysis unit 2 and the inlet of the oxidation unit 3; the purification unit 4 is connected to the exhaust ports of the pyrolysis unit 2 and the oxidation unit 3 respectively to purify the pyrolysis gas generated by pyrolysis and the flue gas generated by oxidation before discharge; the heat exchanger 5 is connected to the exhaust port of the purification unit 4 to recover heat from the purified waste gas.

[0031] This invention, through the inclusion of a pyrolysis unit 2 and an oxidation unit 3, ensures thorough resin removal from fan blade fragments, reduces surface residue, and improves the quality of recycled glass fiber. The inclusion of a heat exchanger 5 allows for the recovery of waste heat from exhaust gas, reducing overall energy consumption and improving economic efficiency. The inclusion of a purification unit 4 effectively treats pollutants generated during the pyrolysis process, preventing atmospheric pollution.

[0032] Furthermore, it also includes a conveying device that runs through the discharge port of the pretreatment unit 1, the pyrolysis unit 2, and the oxidation unit 3 to transport the fan blade fragments, thereby achieving continuous operation, automated operation, and improved processing efficiency.

[0033] Furthermore, it also includes a PLC automatic control system to monitor parameters such as temperature, pressure, and flow rate of the pyrolysis unit 2 and the oxidation unit 3 in real time, so as to achieve precise control.

[0034] In some embodiments, the pretreatment unit 1 includes a cutter, a biaxial shear crusher, and a vibrating screen. The cutter is used to cut the fan blades into blocks, the biaxial shear crusher is used to crush the block fan blades into fragments, and the vibrating screen is used to remove impurities from the fragments.

[0035] Furthermore, the fragments are fed into pyrolysis unit 2 via a screw feeder.

[0036] In some embodiments, the pyrolysis unit 2 includes a pyrolysis furnace having an inert gas inlet connected to a gas source via an inert gas pipeline connected to a heat exchanger 5, wherein the heat recovered by the heat exchanger 5 preheats the inert gas.

[0037] Furthermore, the pyrolysis furnace is an indirect heating pyrolysis furnace with controllable temperature.

[0038] In some embodiments, inert gas protection devices are connected to the feed inlet and discharge outlet of the pyrolysis furnace to prevent damage to the inert atmosphere inside the pyrolysis furnace.

[0039] In some embodiments, the purification unit 4 includes a multi-stage condenser and an activated carbon adsorption device. The multi-stage condenser is used to condense and recover the oil in the pyrolysis gas, and the activated carbon adsorption device is used to adsorb the dust in the pyrolysis gas and flue gas.

[0040] In some embodiments, the pyrolysis furnace is a low-temperature pyrolysis furnace with a heating temperature below 600°C. This can reduce thermal damage to the glass fibers, maintain their mechanical properties, and improve the recycling quality.

[0041] In some embodiments, the oxidation unit 3 includes an oxidation furnace and a gas distributor, wherein the gas distributor is disposed inside the furnace cavity of the oxidation furnace and connected to the gas inlet of the oxidation furnace.

[0042] Another embodiment of the present invention provides a method for preparing glass fibers for wind turbine blades, which utilizes the above-mentioned system for preparing glass fibers for wind turbine blades and includes the following steps:

[0043] S1. Using pretreatment unit 1, the fan blades are broken into fragments with a side length of 5-10cm, and impurities are removed.

[0044] S2. The fragments are introduced into the pyrolysis unit 2 and heated to 400-600°C under an inert atmosphere to pyrolyze the resin in the fragments, obtaining pyrolysis products and oil and gas. The oil and gas are then introduced into the purification unit 4 to remove pollutants and recover chemicals (such as pyrolysis oil, which can be used as chemical raw materials).

[0045] S3. The pyrolysis products are passed into oxidation unit 3 and heated to 300-500°C in an oxygen atmosphere to oxidize the pyrolysis products, remove residual carbon on the surface, and obtain glass fiber and flue gas. The glass fiber is recycled, and the flue gas is passed into purification unit 4 to remove pollutants and recover chemicals, and then discharged into the air.

[0046] The method of this invention, through a pyrolysis-oxidation coupled process, ensures thorough resin removal from wind turbine blade fragments, reduces surface residue to <3%, and improves the quality of recycled glass fiber. By lowering the pyrolysis temperature, thermal damage to the glass fiber is reduced, preserving its mechanical properties, with a tensile strength retention rate of ≥75%. This enables efficient, continuous production and meets environmental standards.

[0047] Furthermore, the aerobic atmosphere is air or oxygen.

[0048] Furthermore, the inert atmosphere is a nitrogen atmosphere.

[0049] In some embodiments, in step S2, the pyrolysis time is 30–60 min and the oxidation time is 20–40 min. These times can be adjusted according to the size of the fragments.

[0050] In some embodiments, in step S3, the exhaust gas discharged from the purification unit 4 preheats the inert gas introduced into the pyrolysis unit 2. This can reduce energy consumption (<0.8 kWh / kg), and the overall energy consumption is reduced by more than 30% compared to traditional pyrolysis.

[0051] The present invention will be further illustrated by specific embodiments below.

[0052] Example 1

[0053] Experimental materials: Fragments of decommissioned wind turbine blades (epoxy resin-based GFRP, size 5cm×5cm).

[0054] Experimental setup: Laboratory-scale pyrolysis-oxidation coupled apparatus (processing capacity 1 kg / h).

[0055] Experimental methods:

[0056] Fragments of the wind turbine blades are placed in the feed hopper and fed into the pyrolysis furnace via a screw feeder. The temperature is increased to 500°C at a rate of 10°C / min under a nitrogen atmosphere and held for 30 minutes. The pyrolysis solid product is transferred to an oxidation furnace and oxidized at 400°C with air for 30 minutes. The oxidized glass fibers are collected and their performance is tested. The oil in the pyrolysis gas is collected by condensation, and the non-condensable gases are purified before being discharged.

[0057] Experimental results:

[0058] The recycled glass fiber surface is clean, with a resin residue rate of 2.5%. Tensile strength testing shows a strength retention rate of 78%. The pyrolysis oil yield is 15%, with a calorific value of 25 MJ / kg.

[0059] Example 2

[0060] Experimental scale: A pilot plant with a processing capacity of 50 kg / h was continuously operated for 72 hours.

[0061] Experimental conditions: pyrolysis temperature: 550℃, oxidation temperature: 450℃, throughput: 50kg / h.

[0062] Waste heat recovery: Preheating nitrogen to 300°C using flue gas.

[0063] The test results are shown in the table below:

[0064]

[0065]

[0066] Data analysis: Pilot-scale tests show that the system for preparing glass fiber for wind turbine blades according to the present invention can achieve continuous and stable operation, with stable quality of recycled fibers, significantly reduced energy consumption, and compliance with environmental protection standards.

[0067] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying 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.

[0069] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to 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.

[0070] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0071] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0072] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A system for preparing glass fibers for wind turbine blades, characterized in that, include: The pretreatment unit is suitable for breaking the fan blades into fragments of 5-10cm and removing impurities. The pyrolysis unit is connected to the pretreatment unit to pyrolyze the fragments; The oxidation unit is connected to the pyrolysis unit to oxidize the pyrolysis fragments and remove surface carbon residue. An openable gate is connected between the discharge port of the pyrolysis unit and the feed port of the oxidation unit. The purification unit is connected to the exhaust port of the pyrolysis unit and the exhaust port of the oxidation unit respectively, so as to purify the pyrolysis gas generated by pyrolysis and the flue gas generated by oxidation before discharge. A heat exchanger is connected to the exhaust port of the purification unit to recover heat from the purified waste gas.

2. The system for preparing glass fiber for wind turbine blades according to claim 1, characterized in that, The pretreatment unit includes a cutter, a twin-shaft shear crusher, and a vibrating screen. The cutter is used to cut the fan blades into blocks, the twin-shaft shear crusher is used to crush the block fan blades into fragments, and the vibrating screen is used to remove impurities from the fragments.

3. The system for preparing glass fiber for wind turbine blades according to claim 1, characterized in that, The pyrolysis unit includes a pyrolysis furnace, which has an inert gas inlet. The inert gas inlet is connected to a gas source through an inert gas pipeline, which is connected to a heat exchanger. The heat recovered by the heat exchanger preheats the inert gas.

4. The system for preparing glass fiber for wind turbine blades according to claim 3, characterized in that, Inert gas protection devices are connected to the feed inlet and discharge outlet of the pyrolysis furnace to prevent damage to the inert atmosphere inside the pyrolysis furnace.

5. The system for preparing glass fiber for wind turbine blades according to claim 1, characterized in that, The purification unit includes a multi-stage condenser and an activated carbon adsorption device. The multi-stage condenser is used to condense and recover the oil in the pyrolysis gas, and the activated carbon adsorption device is used to adsorb the dust in the pyrolysis gas and flue gas.

6. The system for preparing glass fiber for wind turbine blades according to claim 1, characterized in that, The pyrolysis furnace is a low-temperature pyrolysis furnace with a heating temperature below 600℃.

7. The system for preparing glass fiber for wind turbine blades according to claim 1, characterized in that, The oxidation unit includes an oxidation furnace and a gas distributor. The gas distributor is located inside the furnace cavity of the oxidation furnace and is connected to the gas inlet of the oxidation furnace.

8. A method for preparing glass fiber for wind turbine blades, characterized in that, The system for preparing glass fiber using the wind turbine blades according to any one of claims 1-7 comprises the following steps: S1. The pretreatment unit is used to break the fan blades into fragments with a side length of 5-10cm and remove impurities. S2. The fragments are fed into the pyrolysis unit and heated to 400-600°C under an inert atmosphere to pyrolyze the fragments, obtaining pyrolysis products and oil and gas. The oil and gas are then fed into the purification unit to remove pollutants and recover chemicals. S3. The pyrolysis products are passed into the oxidation unit and heated to 300-500°C in an oxygen atmosphere to oxidize the pyrolysis products, remove residual carbon on the surface, and obtain glass fiber and flue gas. The flue gas is then passed into the purification unit to remove pollutants and recover chemicals, and then discharged into the atmosphere.

9. The method for preparing glass fiber for wind turbine blades according to claim 8, characterized in that, In step S2, the pyrolysis time is 30–60 min and the oxidation time is 20–40 min.

10. The method for preparing glass fiber for wind turbine blades according to claim 8, characterized in that, In step S3, the exhaust gas discharged from the purification unit preheats the inert gas introduced into the pyrolysis unit.

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