Recycling device and recycling method for photovoltaic multi-layer stacked assembly

Abstract

The invention discloses a recovery device and a recovery method for a photovoltaic multi-layer stacked assembly. The recovery device comprises a dismounting unit, a pyrolysis unit and a waste gas treatment unit which are arranged in sequence, the pyrolysis unit comprises a tunnel kiln, a bearing assembly and a conveying assembly. The recycling method comprises the steps that S1, the disassembling unit is used for disassembling, and the frame is stripped; s2, the photovoltaic multi-layer laminated assembly is sent to a pyrolysis unit for pyrolysis, and a glue film layer in the photovoltaic multi-layer laminated assembly is removed; and S3, the waste gas is discharged after being treated. By means of the innovative disassembling system, the multi-plate stacking tunnel kiln pyrolysis scheme and the multi-stage waste gas treatment system, the industrial production capacity of treating 1-3 tons of photovoltaic panels per hour can be achieved, the pyrolysis effect is good, the silicon material recovery rate can reach 98.5% or above, energy consumption is low, and the tail gas emission index is superior to the national standard by 50% or above.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic solid waste recycling technology, and in particular to a recycling device and method for photovoltaic multilayer stacked modules. Background Technology

[0002] The recycling of photovoltaic modules is the last link in the photovoltaic industry chain and is also regarded as the "last mile" of the entire photovoltaic green industry chain. As a new type of solid waste, the harmless treatment and efficient recycling of retired photovoltaic modules can reduce the secondary pollution caused by the modules after retirement, and recover a large amount of valuable metals and materials, which has huge economic benefits, environmental value and social effects.

[0003] In conventional photovoltaic module recycling processes, the following problems often exist: (1) In order to avoid the problem of low silicon material recovery rate in traditional mechanical crushing methods, existing technologies generally use fixed pyrolysis furnaces to pyrolyze the film layer before recycling silicon material. However, this method has low processing capacity and cannot form continuous operation and production, which restricts industrial development; (2) Exhaust gas treatment in existing pyrolysis processes is incomplete. Often only bag filters are used, which easily generate pollutants such as dioxins and acidic gases. Direct emission will lead to environmental pollution. Summary of the Invention

[0004] This invention provides a recycling device and method for photovoltaic multilayer stacked modules to solve the technical problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows: A recycling device for a photovoltaic multilayer stacked module includes a dismantling unit, a pyrolysis unit, and an exhaust gas treatment unit arranged sequentially. The dismantling unit is used to remove the frame of the photovoltaic multilayer stacked module. The pyrolysis unit is used to pyrolyze the photovoltaic multilayer stacked module after the frame has been removed. The exhaust gas treatment unit is used to treat the exhaust gas generated during the pyrolysis process. The pyrolysis unit includes a tunnel kiln, a support component, and a transport component. The support component is used to load the photovoltaic multilayer stacked module after the frame has been removed. The transport component is used to transport the support component from one end of the tunnel kiln to the other end of the tunnel kiln at a set speed.

[0006] This invention enables fully automated processing, solving the inefficiency problem caused by the segmented and independent operation of traditional processes. It replaces the fixed pyrolysis furnace with a tunnel kiln commonly used in ceramic production, and uses a transport component to deliver the support component at a set speed, breaking through the intermittent bottleneck of the fixed pyrolysis furnace, realizing continuous production, and improving processing efficiency and output. At the same time, it avoids pollution through an end-of-pipe waste gas treatment unit.

[0007] As a further preferred embodiment of the above technical solution, the tunnel kiln is divided into a preheating zone, a pyrolysis zone, and a cooling zone; the length of the tunnel kiln is 10-100 meters, which can be adjusted and determined according to actual production capacity requirements; the tunnel kiln consists of several temperature zones with independently controllable temperatures. This invention achieves continuous production through continuous transmission via a tunnel kiln, a support assembly, and zoned temperature control. The tunnel kiln length is adjustable (10-100 meters), directly matching production capacity requirements and supporting large-scale industrial applications. Simultaneously, gradient temperature control protects the integrity of silicon wafers, improves silicon material recovery rate, optimizes pyrolysis efficiency, reduces energy waste, and prevents localized overheating and contaminant generation.

[0008] As a further preferred embodiment of the above technical solution, the transport component includes several drive rollers, and both the transport component and the support component are made of high-temperature resistant stainless steel. This design ensures structural stability under high-temperature conditions, avoids downtime for maintenance due to deformation or corrosion, extends equipment lifespan, and reduces long-term operation and maintenance costs.

[0009] As a further preferred embodiment of the above technical solution, the waste gas treatment unit includes a secondary combustion chamber, an alkaline spray tower, an electrostatic precipitator, and a CO treatment device arranged sequentially along the gas conveying direction. This invention employs a multi-stage synergistic purification design: the secondary combustion chamber thoroughly decomposes organic pollutants such as dioxins; the alkaline spray tower neutralizes acidic gases (such as HCl and SO2) to prevent corrosion and pollution; the electrostatic precipitator efficiently captures micron-sized particulate matter; and finally, the CO treatment device specifically treats residual CO to prevent the emission of toxic gases, thereby achieving near-zero pollution emissions and meeting stringent environmental standards.

[0010] As a further preferred embodiment of the above technical solution, the electrode spacing of the electrostatic precipitator is 200mm. This design optimizes the electric field distribution and dust removal efficiency, improves the removal rate of fine particulate matter, reduces equipment size, and lowers energy consumption.

[0011] As a further preferred embodiment of the above technical solution, the waste gas treatment unit and the pyrolysis unit are connected by an exhaust pipe. The exhaust pipe includes exhaust branch pipes and an exhaust main pipe connected at one end to the waste gas treatment unit. The exhaust main pipe is connected to the flue gas outlet of each temperature zone of the tunnel kiln through several exhaust branch pipes. The exhaust pipe network design allows for independent collection of waste gas in different zones, ensuring effective waste gas collection.

[0012] As a further preferred embodiment of the above technical solution, the inner wall of the exhaust branch pipe is provided with a corrosion-resistant and heat-resistant lining. The corrosion-resistant and heat-resistant lining can effectively help the exhaust branch pipe resist high-temperature acid corrosion (where the exhaust gas temperature is the highest), prevent exhaust gas leakage due to pipe damage, reduce maintenance frequency, and ensure continuous system operation.

[0013] As a further preferred embodiment of the above technical solution, the main exhaust pipe is composed of several exhaust pipe sections, and adjacent exhaust pipe sections are connected by corrugated pipe expansion joints; the corrugated pipe expansion joints are covered with an insulation layer. The corrugated pipe expansion joints can compensate for thermal expansion and contraction stress and prevent pipe cracking; the insulation layer is used to reduce heat loss, maintain exhaust gas temperature, prevent condensation and blockage, and at the same time save energy and reduce consumption.

[0014] Based on the same technical concept, the present invention also provides a method for recycling photovoltaic multilayer stacked modules, implemented using the photovoltaic multilayer stacked module recycling device described above, including the following steps: S1. The photovoltaic multilayer stacked module is disassembled using the disassembly unit, and the frame is peeled off to obtain the disassembled photovoltaic multilayer stacked module. S2. The disassembled photovoltaic multilayer stacked modules are sent to the pyrolysis unit for pyrolysis to remove the encapsulant layer in the photovoltaic multilayer stacked modules, thereby realizing the recovery of each valuable resource of the photovoltaic multilayer stacked modules. S3. Use an exhaust gas treatment unit to collect the exhaust gas generated by pyrolysis in S2 and treat the exhaust gas before discharging it.

[0015] As a further preferred embodiment of the above technical solution, in S2, the disassembled photovoltaic multilayer stacked module undergoes preheating, pyrolysis, and cooling sequentially during the pyrolysis process. The preheating temperature is 450~530℃, the pyrolysis temperature is 600~830℃, and the cooling temperature is 150℃. The total time for the pyrolysis process of the disassembled photovoltaic multilayer stacked module is 18min~40min.

[0016] As a further preferred embodiment of the above technical solution, in S3, the waste gas undergoes secondary combustion, alkaline spraying, and electrostatic dust removal sequentially in the waste gas treatment unit. The temperature of the secondary combustion is 850℃, and the secondary combustion time is greater than 2 seconds. The pH of the alkaline solution used for alkaline spraying is 9.0~9.5, and the liquid-to-gas ratio is controlled at 1.5L / m³ during the spraying process. 3 In electrostatic dust removal, the electrostatic precipitator uses a 15kV DC electric field.

[0017] As a further preferred embodiment of the above technical solution, in S3, after the waste gas is treated by the waste gas treatment unit, the dioxin emission concentration is <0.1ng-TEQ / m³, the dust emission is ≤10mg / m³, and the HF removal rate in the waste gas is ≥99.8%.

[0018] The present invention has the following beneficial effects: This invention, on the one hand, replaces the existing fixed pyrolysis furnace with a tunnel kiln to improve processing efficiency; on the other hand, it achieves environmentally friendly production by optimizing the waste gas treatment unit. Through modular collaborative innovation, it achieves technological breakthroughs in two dimensions: continuity (tunnel kiln) and environmental protection (three-stage waste gas treatment). It combines high economic efficiency with environmental compliance, providing an industrial model for the photovoltaic recycling industry. It can achieve an industrial production capacity of processing 1 to 3 tons of photovoltaic panels per hour, with good pyrolysis effect, silicon material recovery rate of over 98.5%, low energy consumption, and exhaust gas emission indicators that are more than 50% lower than national standards.

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart of the recycling method for photovoltaic multilayer stacked modules in Example 1; Figure 2 This is a schematic diagram of the pyrolysis unit and exhaust pipe of the recycling device for the photovoltaic multilayer stacked module in Example 1; Figure 3 This is a schematic diagram of the waste gas treatment unit of the recycling device for the photovoltaic multilayer stacked module in Example 1; Figure 4 This is a schematic diagram showing the arrangement of the exhaust main pipe and exhaust branch pipe of the recycling device for the photovoltaic multilayer stacked module in Example 1; Figure 5 This is a schematic diagram (cross-sectional view) of the exhaust main pipe and exhaust branch pipe arrangement of the recycling device for the photovoltaic multilayer stacked module in Example 1.

[0021] Legend: 1. Tunnel kiln; 2. Supporting components; 3. Transport components; 4. Secondary combustion chamber; 5. Alkali spray tower; 6. Electrostatic precipitator; 7. CO treatment device; 8. Exhaust pipe; 11. Temperature zone; 81. Main exhaust pipe; 82. Branch exhaust pipe; 811. Exhaust pipe section; 812. Corrugated pipe expansion joint; 821. Corrosion-resistant and heat-resistant lining material; 822. Exhaust valve. Detailed Implementation

[0022] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0023] Example 1: The photovoltaic multilayer stacked module recycling device of this embodiment includes a dismantling unit, a pyrolysis unit and an exhaust gas treatment unit arranged in sequence. The dismantling unit is used to dismantle the frame of the photovoltaic multilayer stacked module, the pyrolysis unit is used to perform pyrolysis treatment on the photovoltaic multilayer stacked module after the frame is removed, and the exhaust gas treatment unit is used to treat the exhaust gas generated by the pyrolysis unit during pyrolysis.

[0024] The disassembly unit can be any existing conventional and efficient frame removal device.

[0025] like Figure 2 As shown (top view), the pyrolysis unit includes a tunnel kiln 1, a support assembly 2 (pallets made of high-temperature resistant stainless steel 310S, each weighing 25kg, each pallet can carry up to 6 photovoltaic multilayer stacked modules) and a transport assembly 3 (transfer rollers, also made of high-temperature resistant stainless steel 310S, with a transmission speed of up to 160m / h). The support assembly 2 is used to load the photovoltaic multilayer stacked modules after the frames have been removed, and the transport assembly 3 is used to transport the support assembly 2 from one end of the tunnel kiln 1 to the other end of the tunnel kiln 1 at a set speed. The tunnel kiln 1 is 45870mm long and is divided into a preheating zone, a pyrolysis zone, and a cooling zone. The tunnel kiln 1 consists of 28 independently temperature-controlled temperature zones 11. The lengths of the preheating zone, pyrolysis zone, and cooling zone can be determined according to actual production needs. In this embodiment, the first 8 temperature zones 11 form the preheating zone, the last 4 temperature zones 11 form the cooling zone, and the remaining temperature zones 11 form the pyrolysis zone.

[0026] like Figure 3 As shown, the exhaust gas treatment unit includes a secondary combustion chamber 4 (regenerative incinerator), an alkaline spray tower 5 (cyclone tower), an electrostatic precipitator 6, and a CO treatment device 7 (CO catalytic combustion integrated machine) arranged sequentially along the gas conveying direction, wherein the electrode spacing of the electrostatic precipitator 6 is 200mm.

[0027] like Figure 4 (Side view, some perspective processing has been applied for easier observation) and Figure 5 (along Figure 4 ┘c,c ’ As shown in the cross-section in the └ direction, the exhaust gas treatment unit and the pyrolysis unit are connected by an exhaust pipe 8. The exhaust pipe 8 includes an exhaust branch pipe 82 and an exhaust main pipe 81 connected at one end to the exhaust gas treatment unit. The exhaust main pipe 81 is connected to the flue gas outlet of each temperature zone 11 of the tunnel kiln 1 through the exhaust branch pipe 82. The exhaust main pipe 81 is composed of several exhaust pipe sections 811. Adjacent exhaust pipe sections 811 are connected by a corrugated pipe expansion joint 812 (also made of high-temperature resistant stainless steel 301S, with a single length of 300mm, a corrugation number of 6, and an expansion amount of 50mm). The corrugated pipe expansion joint 812 is covered with an insulation layer (50mm carbon fiber blanket and an outermost 0.5mm stainless steel plate).

[0028] In this embodiment, both the exhaust branch pipe 82 and the exhaust main pipe 81 adopt double-layer jacketed pipes. The jacket of the exhaust branch pipe 82 is filled with corrosion-resistant and heat-resistant lining material 821. The inner pipe of the exhaust branch pipe 82 is welded to the inner pipe of the exhaust main pipe 81, and the outer pipe is welded to the outer pipe of the exhaust main pipe 81. An exhaust valve 822 is provided on the inner pipe of the exhaust branch pipe 82 near the exhaust main pipe 81.

[0029] like Figure 1 As shown, the recycling method for photovoltaic multilayer stacked modules in this embodiment includes the following steps: S1. Use the disassembly unit to disassemble the photovoltaic multilayer stacked module, peel off the frame, and obtain the disassembled photovoltaic multilayer stacked module; S2. The disassembled photovoltaic multilayer stacked modules are fed into the support module 2 located on the transport module 3 by a feeding robot, and then transported to the tunnel kiln 1 of the pyrolysis unit for pyrolysis to remove the encapsulant layer in the photovoltaic multilayer stacked modules. During the pyrolysis process, the modules are preheated, pyrolyzed and cooled in sequence. The preheating temperature is 450~530℃ (increasing sequentially in the preheating zone) and the preheating time is 12.7min. The pyrolysis temperature is 600~630℃ (increasing first and then decreasing in the pyrolysis zone) and the pyrolysis time is 20min. The cooling temperature is 150℃ and the cooling time is 7.3min. After the pyrolysis is completed, the material is unloaded by a flipper and transported to the next processing unit for screening and recycling to obtain valuable resources. S3. The waste gas generated by pyrolysis in S2 is collected through exhaust pipe 8 and treated by the waste gas treatment unit before being discharged. During the treatment process, the waste gas first enters the secondary combustion chamber 4 for secondary combustion at a temperature of 850℃. The residence time of the waste gas in the secondary combustion chamber 4 is greater than 2 seconds. After secondary combustion, the waste gas enters the alkaline spray tower 5 for spray treatment. The pH of the alkaline solution is 9.0~9.5, and the liquid-to-gas ratio is controlled at 1.5L / m³ during the spraying process. After the spraying is completed, the waste gas is then transported to the electrostatic precipitator 6 (working electric field is 15kV DC electric field) for treatment. After treatment, it is then treated by the CO treatment device 7 before being discharged.

[0030] After testing, the dioxin emission concentration was 0.87 ng-TEQ / m³, the dust emission was 6.9 mg / m³, and the HF removal rate in the exhaust gas was 99.93%.

[0031] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and modifications obtained without departing from the inventive concept should also be considered within the scope of protection of the present invention.

[0032] 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 recycling device for a multilayer photovoltaic module, characterized in that, The device includes a dismantling unit, a pyrolysis unit, and an exhaust gas treatment unit arranged sequentially. The dismantling unit is used to dismantle the frame of the photovoltaic multilayer stacked module. The pyrolysis unit is used to perform pyrolysis treatment on the photovoltaic multilayer stacked module after the frame is removed. The exhaust gas treatment unit is used to treat the exhaust gas generated during the pyrolysis of the pyrolysis unit. The pyrolysis unit includes a tunnel kiln (1), a support component (2), and a transport component (3). The support component (2) is used to load the photovoltaic multilayer stacked module after the frame is removed. The transport component (3) is used to transport the support component (2) from one end of the tunnel kiln (1) to the other end of the tunnel kiln (1) at a set speed.

2. The recycling device for photovoltaic multilayer stacked modules according to claim 1, characterized in that, The tunnel kiln (1) is divided into a preheating zone, a pyrolysis zone and a cooling zone; the length of the tunnel kiln (1) is 10 to 100 meters; the tunnel kiln (1) is composed of several temperature zones (11) whose temperature can be controlled independently.

3. The recycling device for photovoltaic multilayer stacked modules according to claim 1, characterized in that, The transport component (3) includes several drive rollers, and both the transport component (3) and the support component (2) are made of high-temperature resistant stainless steel.

4. The recycling device for photovoltaic multilayer stacked modules according to any one of claims 1-3, characterized in that, The waste gas treatment unit includes a secondary combustion chamber (4), an alkaline spray tower (5), an electrostatic precipitator (6), and a CO treatment device (7) arranged sequentially along the gas conveying direction.

5. The recycling device for photovoltaic multilayer stacked modules according to any one of claims 1-3, characterized in that, The waste gas treatment unit and the pyrolysis unit are connected by an exhaust pipe (8). The exhaust pipe (8) includes an exhaust branch pipe (82) and an exhaust main pipe (81) connected at one end to the waste gas treatment unit. The exhaust main pipe (81) is connected to the flue gas outlet of each temperature zone (11) of the tunnel kiln (1) through several exhaust branch pipes (82).

6. The recycling device for photovoltaic multilayer stacked modules according to claim 5, characterized in that, The inner wall of the exhaust branch pipe (82) is provided with a corrosion-resistant and heat-resistant lining.

7. The recycling device for photovoltaic multilayer stacked modules according to claim 5, characterized in that, The exhaust main pipe (81) is composed of several exhaust pipe sections (811), and adjacent exhaust pipe sections (811) are connected by corrugated pipe expansion joints (812); the corrugated pipe expansion joints (812) are covered with a heat insulation layer.

8. A method for recycling photovoltaic multilayer stacked modules, characterized in that, The recycling method is implemented using the photovoltaic multilayer cascaded module recycling apparatus according to any one of claims 1-7, and includes the following steps: S1. The photovoltaic multilayer stacked module is disassembled using the disassembly unit, and the frame is peeled off to obtain the disassembled photovoltaic multilayer stacked module. S2. The disassembled photovoltaic multilayer stacked modules are sent to the pyrolysis unit for pyrolysis to remove the encapsulant layer in the photovoltaic multilayer stacked modules, thereby realizing the recovery of each valuable resource of the photovoltaic multilayer stacked modules. S3. Use an exhaust gas treatment unit to collect the exhaust gas generated by pyrolysis in S2 and treat the exhaust gas before discharging it.

9. The method for recycling photovoltaic multilayer stacked modules according to claim 8, characterized in that, In S2, the disassembled photovoltaic multilayer stacked module undergoes preheating, pyrolysis, and cooling sequentially during the pyrolysis process. The preheating temperature is 450~530℃, the pyrolysis temperature is 600~830℃, and the cooling temperature is 150℃. The total time for the pyrolysis process of the disassembled photovoltaic multilayer stacked module is 18min~40min.

10. The method for recycling photovoltaic multilayer stacked modules according to claim 8, characterized in that, In S3, the waste gas undergoes secondary combustion, alkaline spraying, electrostatic dust removal, and CO catalytic combustion in the waste gas treatment unit. The temperature of the secondary combustion is 850℃, and the secondary combustion time is greater than 2s. The pH of the alkaline solution used in the alkaline spraying treatment is 9.0~9.

5. The electrostatic dust removal treatment uses a 15kV DC electric field in the electrostatic precipitator.

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