Atmosphere-controlled crystalline silicon photovoltaic panel continuous pyrolysis recovery method and system

Abstract

The invention discloses an atmosphere-controlled crystalline silicon photovoltaic panel continuous pyrolysis recovery method which comprises the following steps: S1, dismantling a frame and a junction box of a waste crystalline silicon photovoltaic panel to obtain a photovoltaic laminated part; s2, continuously conveying the photovoltaic laminated part into a continuous pyrolyzing furnace, and enabling the photovoltaic laminated part to sequentially pass through a preheating area, a pyrolyzing area and a slow cooling area; s3, inert gas is introduced into the continuous pyrolyzing furnace, and the interior of the furnace is kept in an oxygen-deficient atmosphere for inhibiting oxidation; s4, the oxygen concentration in the pyrolysis area is monitored in real time, a monitoring signal is fed back to a control system, and the control system adjusts the introduction flow or introduction point location of the inert gas according to the deviation between the oxygen concentration and a set value; s5, guiding out and combusting pyrolysis gas generated in the pyrolysis process, and preferentially conveying the generated high-temperature flue gas to the pyrolysis area to provide heat for the pyrolysis reaction; and S6, sorting the pyrolyzed and slowly cooled photovoltaic laminated pieces, and separating and recycling photovoltaic glass, battery pieces and metal materials.

Description

Technical Field

[0001] This invention relates to the field of waste photovoltaic module recycling technology, specifically to a continuous pyrolysis recycling method and system for crystalline silicon photovoltaic panels with atmosphere control. Background Technology

[0002] With the rapid development of the photovoltaic industry, early-installed photovoltaic modules are about to enter their large-scale retirement period, and the recycling of these used photovoltaic modules has become an urgent environmental and resource issue. Crystalline silicon photovoltaic modules mainly consist of photovoltaic glass, solar cells (silicon wafers), EVA film, backsheet, aluminum frame, and junction box. The EVA film, through thermosetting, tightly bonds the glass and solar cells, making the modules difficult to separate and recycle.

[0003] Currently, the main methods for recycling photovoltaic modules include chemical reagent methods and pyrolysis methods. The conventional method is screening and separation, which easily leads to cell breakage and makes the mixed materials difficult to separate. While chemical reagent methods offer good separation results, the use of organic solvents can cause secondary pollution and has high processing costs. Pyrolysis utilizes high temperatures to decompose and vaporize the EVA film, thereby separating the glass from the cells. Because it does not require chemical reagents and yields high-purity recyclable materials, it has become a current research hotspot.

[0004] However, existing pyrolysis recycling technologies for crystalline silicon photovoltaic panels still have the following shortcomings in practical applications. Although EVA can undergo pyrolysis under different atmospheres, these atmospheres directly affect the reaction path and product morphology. To improve pyrolysis efficiency and facilitate subsequent product recovery, it is still necessary to reasonably control oxygen concentration and carrier gas conditions. Existing systems generally lack real-time monitoring and dynamic closed-loop adjustment mechanisms for the furnace atmosphere (especially oxygen content). If the oxygen concentration is too high, it can easily trigger a violent oxidation reaction, potentially leading to the formation of oxide films on valuable metals on the cell surface and silicon wafer surface, or even causing the silicon wafer to break due to excessive thermal stress. If the oxygen concentration is too low or the carrier gas flow design is unreasonable, it can easily lead to carbides from EVA pyrolysis remaining on the photovoltaic glass or cell surface, affecting subsequent sorting. To improve pyrolysis efficiency, the pyrolysis reaction often needs to be carried out at a high temperature, resulting in high energy consumption. Existing pyrolysis processes typically rely on natural gas or electric heating as heat sources, which is a one-way consumption mode. Although the pyrolysis of photovoltaic panels produces combustible pyrolysis gas containing hydrocarbons, current technologies often treat this as waste gas for direct emission or as simple combustion before emission, failing to reuse this high-temperature combustible pyrolysis gas for the pyrolysis furnace's own heat supply, resulting in energy waste. Intermittent (batch) pyrolysis equipment suffers significant heat loss due to repeated temperature rises and falls during batch production; conventional continuous pyrolysis equipment lacks reasonable zoned heat management, failing to achieve cascaded utilization of heat energy from the pyrolysis zone to the preheating zone within the system, leading to a large additional energy consumption during the preheating stage, further increasing overall processing costs. Summary of the Invention

[0005] In order to overcome the technical defects of low precision in pyrolysis atmosphere control and poor energy utilization efficiency of the above-mentioned technologies, the present invention provides a method and system for continuous pyrolysis recovery of crystalline silicon photovoltaic panels with atmosphere control.

[0006] To solve the above problems, the present invention is implemented according to the following technical solution:

[0007] In a first aspect, the present invention provides a method for continuous pyrolysis and recycling of crystalline silicon photovoltaic panels with controlled atmosphere, comprising the following steps:

[0008] S1: Remove the frame and junction box of the waste crystalline silicon photovoltaic panel to obtain the photovoltaic laminate;

[0009] S2: The photovoltaic laminate is continuously conveyed to a continuous pyrolysis furnace, so that it passes through the preheating zone, the pyrolysis zone and the slow cooling zone in sequence;

[0010] S3: Inert gas is introduced into the continuous pyrolysis furnace to maintain an oxygen-deficient atmosphere that inhibits oxidation.

[0011] S4: Monitor the oxygen concentration in the pyrolysis zone in real time and feed the monitoring signal back to the control system. The control system adjusts the inert gas flow rate or inlet point according to the deviation between the oxygen concentration and the set value.

[0012] S5: The pyrolysis gas generated during the pyrolysis process is extracted and burned, and the high-temperature flue gas generated is preferentially transported to the pyrolysis zone to provide heat for the pyrolysis reaction;

[0013] S6: The photovoltaic laminates after pyrolysis and slow cooling are sorted to separate and recycle photovoltaic glass, solar cells and metal materials.

[0014] In conjunction with the first aspect, the present invention provides a first specific implementation of the first aspect, specifically, in step S4, the oxygen concentration at at least one monitoring point in the pyrolysis zone is monitored in real time; wherein, the monitoring point and the inert gas inlet point are spaced apart.

[0015] In conjunction with the first aspect, the present invention provides a second specific implementation of the first aspect, specifically, step S4 includes:

[0016] When the oxygen concentration is detected to exceed the first set range, the control system increases the inert gas flow rate into the preheating zone;

[0017] When the oxygen concentration is detected to exceed the second set range and the duration exceeds 30 seconds, the control system simultaneously performs the following operations: opens the backup inert gas inlet valve located at the tail of the furnace body and starts the blower to apply negative pressure to the furnace.

[0018] Wherein, the second setting range is higher than the first setting range.

[0019] In conjunction with the first aspect, the present invention provides a third specific implementation of the first aspect. Specifically, in step S5, the high-temperature flue gas generated by combustion first flows through the heating jacket provided in the pyrolysis zone, and then flows into the heating jacket provided in the preheating zone, thereby realizing the graded utilization of thermal energy.

[0020] In conjunction with the first aspect, the present invention provides a fourth specific implementation of the first aspect, wherein the continuous pyrolysis furnace is a mesh belt furnace, a steel belt furnace, or a roller furnace.

[0021] In conjunction with the first aspect, the present invention provides a fifth specific embodiment of the first aspect, wherein the pyrolysis gas is transported through an insulated pipeline to a combustion system integrated with the continuous pyrolysis furnace.

[0022] In conjunction with the first aspect, the present invention provides a sixth specific implementation of the first aspect. Specifically, in step S6, the photovoltaic laminate after pyrolysis and slow cooling is sorted, specifically by at least one of wind sorting, gravity sorting, magnetic sorting or eddy current sorting.

[0023] In conjunction with the first aspect, the present invention provides a seventh specific embodiment of the first aspect, wherein the temperature of the pyrolysis zone is related to the residence time and satisfies the following conditions:

[0024] The pyrolysis temperature is 480-550℃, and the residence time is 18-60 minutes.

[0025] In conjunction with the first aspect, the present invention provides an eighth specific embodiment of the first aspect, wherein the oxygen-deficient atmosphere for inhibiting oxidation is to control the oxygen volume concentration in the furnace to not exceed 8%.

[0026] In a second aspect, the present invention also provides an atmosphere-controlled continuous pyrolysis recovery system for crystalline silicon photovoltaic panels, used to implement the atmosphere-controlled continuous pyrolysis recovery method for crystalline silicon photovoltaic panels described in the first aspect of the present invention, comprising:

[0027] A preprocessing unit is used to remove the photovoltaic panel frame and junction box to obtain a photovoltaic laminate.

[0028] A continuous pyrolysis furnace is provided, which has a preheating zone, a pyrolysis zone and a slow cooling zone arranged sequentially inside. The continuous pyrolysis furnace is used for continuous conveying and heat treatment of photovoltaic laminates. The tail end of the continuous pyrolysis furnace is also provided with an exhaust fan and a backup inert gas inlet valve. The control system is electrically connected to the exhaust fan and the backup inert gas inlet valve respectively.

[0029] An atmosphere control system, comprising an inert gas source, a gas delivery pipeline assembly, a flow regulating valve group, an oxygen monitoring assembly, and a control system;

[0030] The gas delivery pipeline assembly is connected to the inert gas source, and its end is provided with an air inlet that extends to the preheating zone and the slow cooling zone respectively;

[0031] The flow regulating valve assembly is installed on the gas delivery pipeline assembly and is used to regulate the flow rate of inert gas entering each zone; the oxygen monitoring assembly includes an oxygen concentration sensor installed in the pyrolysis zone;

[0032] The control system is electrically connected to the oxygen concentration sensor and the flow regulating valve group respectively, and controls the opening degree of the flow regulating valve group according to the feedback signal of the oxygen concentration sensor.

[0033] An energy recovery system includes a burner connected to the pyrolysis zone via an insulated pipe for burning pyrolysis gas and generating high-temperature flue gas. The high-temperature flue gas generated by the burner is first connected to the heating jacket of the pyrolysis zone via an insulated pipe, and then connected to the heating jacket of the preheating zone.

[0034] The sorting and recycling unit is used to sort the pyrolyzed photovoltaic laminates.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows: In step S1, by removing the frame and junction box, the volume of material and non-target materials entering the pyrolysis furnace are reduced, preventing the aluminum alloy frame and junction box materials from polluting the furnace environment or interfering with the pyrolysis reaction during subsequent high-temperature processes. In step S2, a continuous conveying method is adopted to increase the throughput per unit time. By sequentially setting up a preheating zone, a pyrolysis zone, and a slow cooling zone, the photovoltaic laminate undergoes a gradual heating and cooling process, reducing the thermal stress caused by rapid temperature changes in the photovoltaic glass and crystalline silicon cells, and reducing material breakage during heat treatment. Compared with intermittent processing, the continuous conveying method increases the throughput per unit time, making it suitable for large-scale industrial applications. In step S3, an oxygen-deficient atmosphere is maintained in the pyrolysis furnace to prevent oxidation of the metal electrodes on the surface of the crystalline silicon cells at high temperatures, improving the purity of subsequent valuable metal recovery; at the same time, it prevents the organic encapsulant film (EVA) from burning in open flame. In step S4, real-time monitoring and control of oxygen concentration are used to adjust the flow rate or introduction point of inert gas according to the actual deviation value, maintaining the oxygen concentration in the furnace. This allows the system to compensate for atmosphere changes caused by air introduced into the feed or fluctuations in the pyrolysis reaction, maintaining the process environment required for EVA pyrolysis. In step S5, the high-temperature flue gas generated after the combustion of pyrolysis gases is transported to the heating jacket of the pyrolysis zone. The chemical and thermal energy in the waste gas is used to provide the heat required for the pyrolysis reaction, reducing the consumption of external heat sources such as natural gas or electricity by the pyrolysis system. Attached Figure Description

[0036] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0037] Figure 1 This is a flowchart of the steps of a continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to the present invention;

[0038] Figure 2 This is a schematic diagram of the process flow of the continuous pyrolysis and recycling system for crystalline silicon photovoltaic panels of the present invention;

[0039] Figure 3 This is a schematic diagram of the structure and temperature zone distribution of the continuous pyrolysis furnace in an embodiment of the present invention;

[0040] Figure 4 This is a flowchart of the atmosphere monitoring and graded response control logic in step S4 of the present invention. Detailed Implementation

[0041] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0042] like Figures 1-4 As shown, the continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to the present invention includes the following steps:

[0043] S1: Remove the frame and junction box of the waste crystalline silicon photovoltaic panel to obtain the photovoltaic laminate;

[0044] S2: The photovoltaic laminate is continuously conveyed into the continuous pyrolysis furnace, so that it passes through the preheating zone, pyrolysis zone and slow cooling zone in sequence;

[0045] S3: Inert gas is introduced into the continuous pyrolysis furnace to maintain an oxygen-deficient atmosphere that inhibits oxidation.

[0046] S4: Real-time monitoring of oxygen concentration in the pyrolysis zone and feedback of the monitoring signal to the control system. The control system adjusts the inert gas flow rate or inlet point according to the deviation between the oxygen concentration and the set value.

[0047] S5: The pyrolysis gases generated during the pyrolysis process are extracted and burned, and the high-temperature flue gas generated is preferentially transported to the pyrolysis zone to provide heat for the pyrolysis reaction.

[0048] S6: The photovoltaic laminates after pyrolysis and slow cooling are sorted to separate and recycle photovoltaic glass, solar cells and metal materials.

[0049] Step S1: Remove the frame and junction box of the waste crystalline silicon photovoltaic panel to obtain the photovoltaic laminate.

[0050] Specifically, the waste crystalline silicon photovoltaic panels are placed with the back panel facing upwards on a conveyor channel and transported to the dismantling unit. Dismantling machinery is used to remove the aluminum alloy frame and junction box. The dismantling device adjusts its operating range according to the size of the photovoltaic panel to prevent damage to the photovoltaic laminate. The photovoltaic laminate obtained after dismantling mainly consists of photovoltaic glass, EVA film, solar cells, and a backsheet.

[0051] Step S2: The photovoltaic laminate is continuously conveyed into a continuous pyrolysis furnace, passing sequentially through the preheating zone, pyrolysis zone, and slow cooling zone. In this embodiment, a mesh belt furnace, steel belt furnace, or roller furnace is selected as the continuous pyrolysis furnace. If a roller furnace is used, a specially designed collection tray made of heat-resistant material is required to prevent the photovoltaic modules from falling into the furnace during pyrolysis. The photovoltaic laminate first enters the heat preservation waiting area at the front of the furnace body, and then enters the preheating zone through a sealing mechanism. The photovoltaic laminate runs continuously under the drive of the conveyor belt, ensuring that the residence time of the same module in the preheating zone and the pyrolysis zone is consistent. As a preferred process parameter, the temperature of the pyrolysis zone is set to 480℃~550℃, and the total residence time of the photovoltaic laminate in the furnace is controlled to be 20 to 60 minutes. Within this temperature range, the EVA film and backsheet undergo pyrolysis and vaporization, while the cells and glass do not melt.

[0052] Step S3: Inert gas is introduced into the continuous pyrolysis furnace to maintain an oxygen-deficient atmosphere that inhibits oxidation. Nitrogen (N2) is preferred as the inert gas. Air curtain sealing mechanisms or sealed transition chambers are installed at the inlet and outlet of the pyrolysis furnace to prevent outside air from seeping in. Nitrogen inlets are also provided in the preheating zone, pyrolysis zone, and slow cooling zone of the pyrolysis furnace. During normal operation, a slight positive pressure is maintained inside the furnace by continuously introducing nitrogen, and the oxygen volume concentration inside the furnace is controlled to not exceed 5% (preferred range) to create an oxygen-deficient environment and prevent oxidation of valuable metals on the surface of the solar cells or open flames from EVA combustion at high temperatures.

[0053] Step S4: Monitor the oxygen concentration in the pyrolysis zone in real time and feed the monitoring signal back to the control system. The control system adjusts the inert gas flow rate or inlet point based on the deviation between the oxygen concentration and the set value. This is the core control step of this embodiment. At least one online oxygen concentration monitor is installed in the pyrolysis zone, with the monitoring point positioned to avoid direct nitrogen inlet flow. The control system (such as a PLC) receives the monitoring data and makes adjustments as follows:

[0054] Level 1 Response (Slight Exceedance): When the oxygen concentration in the pyrolysis zone exceeds the first set range (e.g., 5%–7%), the control system issues a command to increase the opening of the nitrogen flow regulating valve at the preheating zone inlet (e.g., by 20%–50%) using a PID control algorithm. Increasing the flow rate in the preheating zone is chosen to rapidly dilute the infiltrated oxygen using nitrogen flow, while avoiding direct impact on the temperature field of the main reaction section of the pyrolysis zone.

[0055] Level 2 Response (Severe or Continuous Exceedance): When the oxygen concentration is detected to exceed the second set range (e.g., >7%) or the duration exceeds the set threshold (e.g., 30 seconds) within the first set range, the control system performs an emergency operation: simultaneously opening the backup inert gas inlet valve located at the tail of the furnace or on the exhaust side (injecting 1.5 times the normal value), and starting the exhaust fan to apply a slight negative pressure (e.g., -50Pa to -100Pa) to the furnace to accelerate the replacement of the furnace atmosphere.

[0056] Step S5: The pyrolysis gases generated during the pyrolysis process are extracted and combusted. The resulting high-temperature flue gas is preferentially transported to the pyrolysis zone to provide heat for the pyrolysis reaction. The mixed gas (containing gaseous tar, small molecule hydrocarbons, etc.) generated from the pyrolysis of photovoltaic laminates is extracted through insulated pipes and directly transported to the combustion system (hot blast furnace) integrated with the pyrolysis furnace. The pyrolysis gas is mixed with supplementary fuel (such as natural gas) and combusted to produce high-temperature flue gas of approximately 750℃~800℃.

[0057] High-temperature flue gas enters the heating jacket outside the pyrolysis zone through a hot air duct. Indirect heat exchange maintains the pyrolysis zone at the target reaction temperature (500℃~550℃). After heat exchange, the flue gas temperature drops to about 650℃ and then flows into the heating jacket of the preheating zone, where residual heat is used to preheat the photovoltaic laminates that have just entered. After heat exchange in the pyrolysis zone, the flue gas temperature drops and then enters the preheating zone to use residual heat to heat the materials, reducing the exhaust temperature to about 200℃.

[0058] Step S6: The photovoltaic laminates after pyrolysis and slow cooling are sorted to separate and recover the photovoltaic glass, solar cells, and metal materials. The photovoltaic laminates, cooled in the slow cooling zone, are removed from the pyrolysis furnace. The EVA film has been completely pyrolyzed, and the solar cells, solder ribbons, and glass are no longer adhered to each other, resulting in a loosely piled state. Using a wind-powered sorting device, the lighter solar cell fragments and solder ribbons are blown away from the glass surface based on the difference in specific gravity of the components. Subsequently, combined with gravity sorting, magnetic sorting (separating copper / tin from the solder ribbons), or eddy current sorting, the photovoltaic glass, silicon solar cells, and metal solder ribbons are collected separately, completing the recycling process.

[0059] In this embodiment, it should be noted that the pyrolysis gas itself is also at a high temperature. Placing the burner and the pyrolysis furnace together serves two purposes: first, to prevent the pyrolysis gas from condensing into tar, and second, to avoid wasting the heat in the pyrolysis gas.

[0060] In conjunction with the first aspect, the present invention provides a first specific implementation of the first aspect, specifically, in step S4, the oxygen concentration at at least one monitoring point in the pyrolysis zone is monitored in real time; wherein the monitoring point and the inert gas inlet point are spaced apart.

[0061] In order to obtain oxygen concentration data after the mixed atmosphere in the furnace and to prevent the sensor probe from being in a high-concentration inert gas flow field, the monitoring point and the inert gas inlet point are set at intervals.

[0062] The specific arrangement is as follows: the monitoring points and the inlet points are staggered in spatial position within the pyrolysis furnace. As an example, the inert gas inlet (inlet point) is located at the bottom or lower side wall of the pyrolysis zone furnace body to facilitate upward gas diffusion; while the oxygen concentration sensor (monitoring point) is located at the top or upper side wall of the pyrolysis zone furnace body, and the two are spaced apart in the axial distance of the furnace body.

[0063] In the initial stage after the inert gas enters the furnace through the inlet, it has not yet fully mixed with the existing pyrolysis atmosphere. A small area around the inlet is filled with high-purity inert gas. If the monitoring point is too close to the inlet point, the sensor probe will be surrounded by a high concentration of inert gas, resulting in a measured oxygen concentration lower than the average level within the furnace. This data deviation can cause the control system to misjudge that the furnace is in a safe oxygen-deficient state, thus failing to take adjustment action when the gas intake should be increased. By setting the monitoring point and the inlet point at an interval, the gas contacted by the sensor probe is the atmosphere after the inert gas has diffused and mixed with the original gas in the pyrolysis zone. This allows the signal fed back to the control system to reflect the actual oxygen concentration in the pyrolysis zone.

[0064] In conjunction with the first aspect, the present invention provides a second specific implementation of the first aspect, specifically, step S4 includes:

[0065] When the oxygen concentration is detected to exceed the first set range, the control system increases the inert gas flow rate into the preheating zone.

[0066] When the oxygen concentration is detected to exceed the second set range and the duration exceeds 30 seconds, the control system simultaneously performs the following operations: opens the backup inert gas inlet valve located at the tail of the furnace body and starts the blower to apply negative pressure to the furnace.

[0067] The second setting range is higher than the first setting range.

[0068] The first set range for the Level 1 response phase is an oxygen volume concentration of 5% to 7%. When the online oxygen concentration monitor detects that the oxygen concentration in the pyrolysis zone is within this range, the control system determines it to be in a "slightly exceeded" state. At this time, the control system issues a command to increase the inert gas flow rate into the preheating zone.

[0069] Specific adjustment method: The control system increases the opening of the electric regulating valve located on the air intake pipe in the preheating zone by 20% to 50% on the original basis.

[0070] Because the preheating zone is close to the feed inlet, it is the area where outside air (oxygen) can most easily penetrate (e.g., through door gaps or with the material). By increasing the nitrogen flow rate in the preheating zone, oxygen can be diluted and blocked before it diffuses into the high-temperature pyrolysis zone. At the same time, this localized adjustment avoids drastic disturbances to the temperature gradient of the main pyrolysis zone.

[0071] The second set range for the secondary response phase is an oxygen volume concentration exceeding 7%. When the oxygen concentration exceeds the second set range and this condition persists for more than 30 seconds, the control system determines it to be a severe exceedance or continuous leakage condition. At this time, the control system simultaneously performs the following combined operations:

[0072] Operation 1: Open the backup inert gas inlet valve located at the rear of the furnace (or on the exhaust side) to inject additional inert gas into the furnace. In one embodiment, the backup inlet flow rate is set to 1.5 times the normal operating flow rate.

[0073] Operation 2: Start the blower to apply negative pressure inside the furnace. Specifically, control the operation of the exhaust blower to maintain the furnace pressure between -50Pa and -100Pa.

[0074] When the primary response fails to suppress the rise in oxygen concentration, it indicates a possible persistent intrusion of external air or abnormal internal reactions. By opening the backup air inlet valve to purge the entire furnace at a high flow rate, and coordinating with negative pressure extraction by the blower, the gas replacement rate inside the furnace can be accelerated, the oxygen concentration reduced, and the photovoltaic module materials prevented from undergoing severe oxidation or uncontrolled combustion in an oxygen-over-oxygen environment.

[0075] In conjunction with the first aspect, the present invention provides a third specific implementation of the first aspect. Specifically, in step S5, the high-temperature flue gas generated by combustion first flows through the heating jacket located in the pyrolysis zone, and then flows into the heating jacket located in the preheating zone, thereby realizing the graded utilization of thermal energy.

[0076] High-temperature flue gas is generated, and the pyrolysis gas containing volatiles produced during the pyrolysis process is transported to the combustion system through insulated pipes. Inside the combustion system, the pyrolysis gas is mixed with supplementary fuel and burned. The high-temperature flue gas generated during combustion has a temperature of 750℃~850℃, and its residence time in the combustion chamber is greater than 2 seconds, causing the decomposition of tar and organic waste gas produced during pyrolysis.

[0077] The first stage utilizes the high-temperature flue gas (750℃~850℃) generated by combustion (heating in the pyrolysis zone). This gas is first introduced into the heating jacket located in the pyrolysis zone via a hot air duct. The high-temperature flue gas flows within the jacket, indirectly exchanging heat with the photovoltaic laminates in the pyrolysis zone through the furnace wall, providing heat for the endothermic pyrolysis reaction and maintaining the pyrolysis zone temperature at 500℃~550℃. During this process, the flue gas releases heat, and its temperature decreases. After heat exchange in the pyrolysis zone, the flue gas temperature drops to approximately 650℃.

[0078] The second stage utilizes the flue gas (approximately 650°C) flowing from the heating jacket in the pyrolysis zone (preheating zone preheating). This flue gas flows into the heating jacket in the preheating zone through guide plates or connecting pipes located between the jackets. At this stage, the flue gas uses its residual heat to heat the room-temperature photovoltaic laminates that have just entered the furnace.

[0079] Before the exhaust gas leaves the preheating jacket and enters the waste gas treatment system, the exhaust temperature is maintained at around 200℃. Maintaining this exhaust temperature above the acid dew point prevents acidic substances in the exhaust gas from condensing and corroding pipelines and post-treatment equipment.

[0080] In conjunction with the first aspect, the present invention provides a fourth specific implementation of the first aspect, specifically, the continuous pyrolysis furnace is a mesh belt furnace or a steel belt furnace.

[0081] In this embodiment, it should be noted that:

[0082] When selecting a mesh belt furnace, the conveyor belt should be made of a high-temperature resistant alloy material. The mesh belt should be configured with a fine mesh (small aperture) or a thicker wire diameter. This prevents small fragments (such as battery cell fragments or welding strips) generated after pyrolysis from passing through the mesh and falling to the bottom of the furnace, thus maintaining the material on the conveyor belt.

[0083] When selecting a steel strip furnace, a solid high-temperature resistant steel strip is used as the carrier to support powdery or fine granular pyrolysis products.

[0084] This embodiment selects a mesh belt furnace, steel belt furnace, or roller furnace to change the motion state and stress conditions of the photovoltaic module during the pyrolysis process, as detailed below:

[0085] If a rotary pyrolysis furnace (rotary kiln) is used, the rotating furnace cylinder causes the photovoltaic modules to be repeatedly lifted, dropped, and tumbled within the furnace. After the EVA film is removed, the photovoltaic cells lose their adhesive support. Under the tumbling impact of the rotary furnace, the brittle silicon cells break into fine powder and mix with the photovoltaic glass powder. Mesh belt furnaces, steel belt furnaces, or roller furnaces use a flat conveying method. The photovoltaic laminates are placed statically on the surface of the conveyor belt and move horizontally through the pyrolysis zone with the conveyor belt. Throughout the heating process, there is no relative movement between the material and the conveyor belt, and no tumbling or dropping occurs. Due to the above stable conveying method, the pyrolysis products maintain their original stacked positional relationship. Among them, glass: due to uniform heating and no impact, photovoltaic glass usually remains in the form of large fragments, possibly existing as nearly complete plates. Cells: after losing EVA bonding, they still basically maintain their original sheet or large fragment shape, lying flat on the glass. Welding strips: remain in continuous or discontinuous strips. Preserving the sheet or strip shape of the material increases the differences in aerodynamic properties between the different components. In the subsequent step S6, when using wind power or gravity screening, the sheet-like battery cells are more easily separated from the block-like glass. If the material is all broken into powder, it is difficult to distinguish them by wind or gravity.

[0086] In conjunction with the first aspect, the present invention provides a fifth specific embodiment of the first aspect, in which the pyrolysis gas is transported through an insulated pipeline to a combustion system integrated with the continuous pyrolysis furnace.

[0087] Combustion systems (such as gas-fired hot air furnaces) are not set up as independent remote units, but are arranged adjacent to the side or top of the continuous pyrolysis furnace. Insulated pipes connect the pyrolysis gas outlet of the pyrolysis furnace to the burner inlet of the combustion system. To shorten the transport path, the pipe length between the pyrolysis gas outlet and the burner inlet is minimized (e.g., the burner is directly connected or connected to the side wall of the pyrolysis section via a short pipe). The outer wall of the pipe is wrapped with high-temperature resistant insulation material (such as aluminosilicate fiber wool or rock wool) to form an insulation layer. The mixed gas generated during the pyrolysis of photovoltaic laminates contains not only small-molecule combustible gases such as methane and hydrogen, but also a large amount of gaseous macromolecular tar (derived from the pyrolysis of EVA film). Tar is gaseous at high temperatures, but undergoes a phase change when the temperature drops below the freezing point, condensing into liquid oil or even a solid gel. If long-distance uninsulated transport is used, the gaseous tar condenses inside the pipe as the temperature decreases, adhering to the inner wall of the pipe, causing the pipe diameter to narrow or even completely block the pipe. This embodiment utilizes short-distance transport combined with pipeline insulation to maintain the temperature of the pyrolysis gas above the condensation point of the tar (e.g., above 350°C) during its transport from the pyrolysis furnace outlet to the burner inlet. The gaseous tar enters the combustion chamber directly in gaseous form to participate in combustion, without undergoing phase change or sedimentation within the transport pipeline. Shortening the transport distance and maintaining insulation preserves the high sensible heat inherent in the pyrolysis gas itself. This heat is carried into the combustion system with the gas, reducing the additional fuel consumption required to reheat the gas to its ignition point.

[0088] In conjunction with the first aspect, the present invention provides a sixth specific implementation of the first aspect. Specifically, in step S6, the photovoltaic laminate after pyrolysis and slow cooling is sorted, specifically by at least one of wind sorting, gravity sorting, magnetic sorting or eddy current sorting.

[0089] After pyrolysis and slow cooling in step S5, the organic binder (EVA film) and backsheet in the photovoltaic laminate have decomposed and vaporized. The photovoltaic laminate is in a loosely stacked state: the photovoltaic glass remains in a relatively intact plate shape at the bottom, while the solar cells (silicon wafers), solder ribbons, and a small amount of pyrolysis residue are dispersed and adhered to the surface of the photovoltaic glass or scattered on the conveyor belt. There is no adhesion between the components.

[0090] Wind-driven sorting (combined with gravity sorting): Air knives or blowers are installed above or to the side of the conveyor belt in the sorting unit. The direction of the airflow is at a set angle (e.g., perpendicular) to the direction of the conveyor belt's movement. Separation is achieved by utilizing the differences in specific gravity (density) and wind-receiving area between photovoltaic glass and solar cells / welding strips.

[0091] Photovoltaic glass: Due to its large mass and high specific gravity, it maintains its original trajectory under the blowing of wind and enters the glass recycling container with the conveyor belt.

[0092] Battery cells and welding strips: Lightweight or in the form of thin sheets, they are displaced by wind, blown off the surface of the conveyor belt, and fall into the valuable material recycling container on the side.

[0093] Pyrolytic carbon deposits: These are in the form of dust and are collected by the dust removal system along with the airflow.

[0094] Separation is achieved by utilizing the difference in magnetic permeability of different materials. The mixed materials pass through a sorting zone equipped with magnetic separators or suspended iron removers.

[0095] Solder strip: It usually contains tinned copper strip or nickel, and has weak magnetic or paramagnetic properties. It is attracted by a magnetic field and carried away from the material flow.

[0096] Solar cells (silicon) and glass: These are non-magnetic materials, not attracted by magnetic fields, and discharged along a straight trajectory.

[0097] Separation is achieved by utilizing the difference in conductivity between different materials. The material passes through an alternating magnetic field region generated by high-speed rotating magnetic poles.

[0098] Metallic materials (silver electrodes, residual aluminum frame): Induced eddy currents are generated inside, producing a repulsive force opposite to the direction of the magnetic field, causing them to be ejected from the material flow.

[0099] Non-metallic materials (glass, silicon wafers): do not generate inductive force and fall naturally.

[0100] As a specific embodiment, wind separation is used to separate the photovoltaic glass from the battery cell / welding ribbon mixture; the collected battery cell / welding ribbon mixture is then subjected to magnetic separation to separate the welding ribbon; the remaining battery cell fragments and silver powder are then processed in subsequent purification steps.

[0101] In conjunction with the first aspect, the present invention provides a seventh specific embodiment of the first aspect, wherein the temperature of the pyrolysis zone is related to the residence time and satisfies the following conditions:

[0102] 480-550℃, stay for 18-60 minutes.

[0103] The control system sets the conveyor belt speed based on the target temperature in the pyrolysis zone, thereby determining the residence time of the photovoltaic laminate in the pyrolysis zone. The two satisfy one of the following correspondences:

[0104] Operating Condition 1: When the pyrolysis temperature is set to 480℃, the residence time is controlled to be about 60 minutes.

[0105] Operating Condition 2: When the pyrolysis temperature is set to 500℃, the residence time is controlled to be 22 to 30 minutes.

[0106] Operating Condition 3: When the pyrolysis temperature is set to 550℃, the residence time is controlled to be 18 to 25 minutes.

[0107] The above parameter combination is determined based on the thermogravimetric characteristics of EVA film and TPT backsheet and the thermal stress resistance of crystalline silicon solar cells.

[0108] Regarding the lower temperature limit (480℃) and residence time: EVA film and backsheet materials enter the maximum weight loss rate range after reaching 480℃. If the temperature is below 480℃, incomplete EVA decomposition may occur. Under these conditions, if the residence time is insufficient, EVA cannot be completely decomposed and vaporized, resulting in carbonized residues on the surface of photovoltaic glass or solar cells, affecting the purity of subsequent sorting. Therefore, at 480℃, a longer residence time (60 minutes) is set to compensate for the insufficient reaction rate by extending the reaction time, ensuring complete EVA decomposition.

[0109] Regarding the upper temperature limit (550℃) and residence time: As the temperature increases, the pyrolysis reaction rate of organic matter accelerates, making it easier for EVA to decompose completely and shortening the required reaction time. If the temperature exceeds 550℃ or the residence time at 550℃ is too long, the crystalline silicon solar cells will experience increased internal thermal stress due to the large temperature difference or prolonged high-temperature baking, leading to a higher probability of physical breakage and making it difficult to obtain intact silicon wafers. Simultaneously, excessively high temperatures or excessively long ineffective heating times increase fuel consumption. Therefore, under 550℃ conditions, a shorter residence time (18-25 minutes) is set to reduce the heat load and energy consumption of photovoltaic modules while ensuring EVA decomposition, thereby improving production efficiency.

[0110] Under the above temperature and time conditions, an oxygen-deficient environment is maintained in the furnace with an oxygen concentration not exceeding 8% (preferably below 5%). If the oxygen concentration is too high (e.g., exceeding 10%), it will promote the formation of coke, requiring higher temperatures or longer times to remove the coke, which conflicts with the goal of protecting the integrity of the solar cells.

[0111] In conjunction with the first aspect, the present invention provides an eighth specific embodiment of the first aspect, specifically, the oxygen-deficient atmosphere for inhibiting oxidation is to control the oxygen volume concentration in the furnace to not exceed 8%.

[0112] During the pyrolysis process, a positive pressure environment is maintained inside the furnace by continuously introducing inert gas (such as nitrogen) and by installing sealing mechanisms at the inlet and outlet. An atmosphere monitoring system monitors the oxygen content in the pyrolysis zone in real time, maintaining the oxygen volume concentration within the range of 0% to 8%. As a preferred embodiment, the oxygen volume concentration is controlled below 5%.

[0113] The above-mentioned upper limit of oxygen concentration (8%) is based on the pyrolysis characteristics of EVA film and the need to protect valuable components:

[0114] The decomposition reaction of EVA film at high temperatures is affected by oxygen concentration. If the oxygen concentration in the furnace exceeds 8% (especially close to or exceeding 10%), the EVA film will undergo a violent exothermic oxidation reaction during pyrolysis. This exothermic reaction causes a rapid increase in the local temperature of the photovoltaic module, subjecting the silicon cells to thermal shock. Due to the difference in thermal expansion coefficients between silicon wafers and glass, drastic temperature changes can cause physical fragmentation of the silicon wafers, reducing the recycling rate of intact cells. Crystalline silicon cells have silver grid lines (Ag) and aluminum back field (Al) printed on their surface. In a high-temperature environment of around 500℃, if the oxygen concentration is too high, an oxide film will form on the surface of the metal electrodes, affecting subsequent recovery of valuable metals. Controlling the oxygen concentration below 8% maintains a reducing atmosphere for the metal materials. According to the mechanism of organic carbonization reaction, excessively high oxygen concentrations (such as above 10%) will lead to the production of more coke (carbonization cross-linking products) during EVA decomposition. Coke adheres to the surface of photovoltaic glass or cells, requiring higher pyrolysis temperatures or longer residence times for removal. By controlling the oxygen concentration below 8%, the amount of coke generated is reduced, which facilitates the complete gasification and separation of EVA.

[0115] In a second aspect, the present invention also provides an atmosphere-controlled continuous pyrolysis recovery system for crystalline silicon photovoltaic panels, used to implement the continuous pyrolysis recovery method for crystalline silicon photovoltaic panels according to the first aspect of the present invention, comprising:

[0116] The preprocessing unit is used to remove the photovoltaic panel frame and junction box to obtain the photovoltaic laminate.

[0117] The continuous pyrolysis furnace has a preheating zone, a pyrolysis zone and a slow cooling zone inside. The continuous pyrolysis furnace is used for continuous conveying and heat treatment of photovoltaic laminates. The tail end of the continuous pyrolysis furnace is also equipped with an exhaust fan and a backup inert gas inlet valve. The control system is electrically connected to the exhaust fan and the backup inert gas inlet valve respectively.

[0118] Atmosphere control system, which includes inert gas source, gas delivery pipeline assembly, flow control valve assembly, oxygen monitoring assembly and control system;

[0119] The gas delivery pipeline assembly is connected to an inert gas source and has air inlets at the end that extend to the preheating zone and the slow cooling zone, respectively.

[0120] The flow control valve assembly is installed on the gas delivery pipeline assembly and is used to regulate the flow rate of inert gas entering each zone; the oxygen monitoring assembly includes an oxygen concentration sensor installed in the pyrolysis zone;

[0121] The control system is electrically connected to the oxygen concentration sensor and the flow regulating valve group respectively, and controls the opening degree of the flow regulating valve group according to the feedback signal of the oxygen concentration sensor.

[0122] The energy recovery system includes a burner connected to the pyrolysis zone via an insulated pipe, which is used to burn pyrolysis gas and generate high-temperature flue gas. The high-temperature flue gas generated by the burner is first connected to the heating jacket of the pyrolysis zone via an insulated pipe, and then connected to the heating jacket of the preheating zone.

[0123] The sorting and recycling unit is used to sort the pyrolyzed photovoltaic laminates.

[0124] 1. Pre-processing unit: Located at the very beginning of the process flow, the pre-processing unit mainly includes a feeding conveyor belt and an automated disassembly robot (or a dedicated frame removal machine). This unit receives waste photovoltaic panels, removes the aluminum alloy frame and junction box through mechanical peeling, and transports the processed photovoltaic laminate to the subsequent pyrolysis process.

[0125] 2. Continuous pyrolysis furnace. In this embodiment, a mesh belt furnace or steel belt furnace with good sealing performance is selected as the continuous pyrolysis furnace. The furnace body is divided into three temperature zones along the material conveying direction: a preheating zone, a pyrolysis zone, and a slow cooling zone. Air curtain sealing devices or double-gate transition chambers are provided at both the feed inlet and discharge outlet of the furnace body to isolate outside air. To cooperate with the secondary response logic in step S4, an exhaust fan and a backup inert gas inlet valve are provided at the tail end of the continuous pyrolysis furnace (or the end of the slow cooling zone). The exhaust fan is connected to the furnace chamber through a pipeline and is used to perform negative pressure evacuation of the furnace in an emergency; the backup inert gas inlet valve is connected to a high-pressure inert gas source for rapid replenishment of gas at a large flow rate. Both the exhaust fan and the backup inert gas inlet valve are electrically connected to the system's control system.

[0126] 3. Atmosphere control system: The atmosphere control system is the core hardware for achieving precise control of the furnace environment, including:

[0127] Inert gas source: such as liquid nitrogen storage tanks or nitrogen generators, providing high-purity nitrogen.

[0128] Gas delivery pipeline assembly: The main pipeline connects to the gas source and extends to the preheating zone and slow cooling zone of the furnace body through branch pipelines. The ends of the branch pipelines serve as gas inlets connected to the furnace, and the gas inlets are designed with multi-point distributed perforated gas distribution pipes.

[0129] Flow regulating valve assembly: Electric proportional regulating valves or mass flow controllers are installed on each branch pipeline leading to the preheating zone and the slow cooling zone to regulate the flow rate of nitrogen gas entering each temperature zone.

[0130] Oxygen monitoring components: These include a high-temperature resistant oxygen concentration sensor (such as a zirconia analyzer) mounted on the furnace wall in the pyrolysis zone. The sensor probe extends into the furnace, and its installation position avoids the direct blowing range of the nitrogen inlet.

[0131] Control system: Employs a programmable logic controller (PLC) or industrial computer. The control system is connected to the oxygen concentration sensor, flow control valve assembly, exhaust fan, and standby intake valve via signal lines. It outputs control signals to adjust valve openings or start / stop the fan.

[0132] 4. Energy recovery system: The energy recovery system realizes closed-loop utilization of pyrolysis gas and its sensible heat. Its structure includes:

[0133] Burner: Preferably a gas-fired hot air furnace, which is integrated with the main body of the pyrolysis furnace (e.g., arranged adjacent to it) to shorten the pipeline length.

[0134] Insulated transport pipeline: Connects the pyrolysis gas outlet at the top of the pyrolysis zone to the fuel inlet of the burner. The outer layer of this pipeline is wrapped with insulating rock wool to prevent gaseous tar from condensing and clogging the pipeline during transport.

[0135] Cascade heating jacket: The high-temperature flue gas outlet generated by the burner is first connected to the heating jacket (first-stage heat exchange) covering the outer wall of the pyrolysis zone through an insulated hot air duct, and then connected to the heating jacket (second-stage heat exchange) covering the outer wall of the preheating zone through a guide pipe. This series-connected jacket structure realizes the cascade utilization of thermal energy.

[0136] 5. Sorting and Recycling Unit: Located downstream of the pyrolysis furnace outlet, this unit is connected to the slow cooling zone via a cooling conveyor belt. It integrates an air-powered separator (using air knives to separate glass from solar cells), a magnetic separator (separating welding strips), and a gravity separation platform to separate the loose pyrolysis material into photovoltaic glass, crystalline silicon solar cells, and metal materials.

[0137] In summary, this invention utilizes the combination of an oxygen concentration sensor and a flow regulating valve assembly to adjust the inert gas flow rate or inlet point based on real-time monitored oxygen concentration data, maintaining an oxygen-deficient environment within the pyrolysis furnace and preventing cell oxidation or carbon residue. The high-temperature flue gas generated from pyrolysis gas combustion is sequentially introduced into the heating jackets of the pyrolysis and preheating zones, utilizing the heat from the flue gas to heat the pyrolysis and preheating processes, reducing external fuel consumption. The use of a mesh belt furnace or steel belt furnace with a flat conveying method and set temperature and residence time parameters ensures that the photovoltaic laminate maintains its layered structure after pyrolysis, facilitating subsequent separation of photovoltaic glass, cells, and metal materials.

[0138] The working principle of the atmosphere-controlled continuous pyrolysis recovery method and system for crystalline silicon photovoltaic panels described in this invention is as follows: During system operation, the pre-treated photovoltaic laminate is transported to a continuous pyrolysis furnace. The atmosphere control system uses an oxygen concentration sensor to detect the oxygen content in the pyrolysis zone. When the detected value is higher than a set threshold, the control system controls the flow regulating valve group to increase the air flow in the preheating zone, or controls the backup air inlet valve to open and starts the exhaust fan for replacement. The photovoltaic laminate is heated in the pyrolysis zone, and the EVA film decomposes to generate pyrolysis gas. The pyrolysis gas is transported to the burner for combustion through an insulated pipe. The generated high-temperature flue gas first flows through the heating jacket of the pyrolysis zone for heat exchange, and the cooled flue gas flows through the heating jacket of the preheating zone for secondary heat exchange before finally being discharged. The pyrolyzed photovoltaic laminate is output after slow cooling, and the photovoltaic glass, solar cells, and metal materials are separated using wind, magnetic, or gravity separation devices.

[0139] Other structures of the atmosphere-controlled continuous pyrolysis recovery method and system for crystalline silicon photovoltaic panels described in this embodiment are referred to in the prior art.

[0140] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for continuous pyrolysis and recycling of crystalline silicon photovoltaic panels with atmosphere control, characterized in that, Includes the following steps: S1: Remove the frame and junction box of the waste crystalline silicon photovoltaic panel to obtain the photovoltaic laminate; S2: The photovoltaic laminate is continuously conveyed to a continuous pyrolysis furnace, so that it passes through the preheating zone, the pyrolysis zone and the slow cooling zone in sequence; S3: Inert gas is introduced into the continuous pyrolysis furnace to maintain an oxygen-deficient atmosphere that inhibits oxidation. S4: Monitor the oxygen concentration in the pyrolysis zone in real time and feed the monitoring signal back to the control system. The control system adjusts the inert gas flow rate or inlet point according to the deviation between the oxygen concentration and the set value. S5: The pyrolysis gas generated during the pyrolysis process is extracted and burned, and the high-temperature flue gas generated is preferentially transported to the pyrolysis zone to provide heat for the pyrolysis reaction; S6: The photovoltaic laminates after pyrolysis and slow cooling are sorted to separate and recycle photovoltaic glass, solar cells and metal materials.

2. The continuous pyrolysis recovery method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that: In step S4, the oxygen concentration at at least one monitoring point within the pyrolysis zone is monitored in real time. The monitoring points and the inert gas inlet points are spaced apart.

3. The continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that, Step S4 specifically includes: When the oxygen concentration is detected to exceed the first set range, the control system increases the inert gas flow rate into the preheating zone; When the oxygen concentration is detected to exceed the second set range and the duration exceeds 30 seconds, the control system simultaneously performs the following operations: opens the backup inert gas inlet valve located at the tail of the furnace body and starts the blower to apply negative pressure to the furnace. The second setting range is higher than the first setting range.

4. The continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that: In step S5, the high-temperature flue gas generated by combustion first flows through the heating jacket located in the pyrolysis zone, and then flows into the heating jacket located in the preheating zone, thereby realizing the graded utilization of thermal energy.

5. The continuous pyrolysis recovery method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that: The continuous pyrolysis furnace is a mesh belt furnace, a steel belt furnace, or a roller furnace.

6. The continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that: The pyrolysis gas is transported through an insulated pipeline to a combustion system integrated with the continuous pyrolysis furnace.

7. The continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that: In step S6, the photovoltaic laminates after pyrolysis and slow cooling are sorted, specifically by at least one of wind sorting, gravity sorting, magnetic sorting or eddy current sorting.

8. The continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that, The temperature in the pyrolysis zone is related to the residence time and satisfies the following condition: The pyrolysis temperature is 480-550℃, and the residence time is 18-60 minutes.

9. The continuous pyrolysis and recycling method for crystalline silicon photovoltaic panels with atmosphere control according to claim 1, characterized in that: The oxygen-deficient atmosphere for inhibiting oxidation is achieved by controlling the oxygen volume concentration in the furnace to not exceed 8%.

10. An atmosphere-controlled continuous pyrolysis recovery system for crystalline silicon photovoltaic panels, used to implement the atmosphere-controlled continuous pyrolysis recovery method for crystalline silicon photovoltaic panels as described in any one of claims 1-8, characterized in that, include: A preprocessing unit is used to remove the photovoltaic panel frame and junction box to obtain a photovoltaic laminate. A continuous pyrolysis furnace is provided, which has a preheating zone, a pyrolysis zone and a slow cooling zone arranged sequentially inside. The continuous pyrolysis furnace is used for continuous conveying and heat treatment of photovoltaic laminates. The tail end of the continuous pyrolysis furnace is also provided with an exhaust fan and a backup inert gas inlet valve. The control system is electrically connected to the exhaust fan and the backup inert gas inlet valve respectively. An atmosphere control system, comprising an inert gas source, a gas delivery pipeline assembly, a flow regulating valve group, an oxygen monitoring assembly, and a control system; The gas delivery pipeline assembly is connected to the inert gas source, and its end is provided with an air inlet that extends to the preheating zone and the slow cooling zone respectively; The flow regulating valve assembly is installed on the gas delivery pipeline assembly and is used to regulate the flow rate of inert gas entering each zone; the oxygen monitoring assembly includes an oxygen concentration sensor installed in the pyrolysis zone; The control system is electrically connected to the oxygen concentration sensor and the flow regulating valve group respectively, and controls the opening degree of the flow regulating valve group according to the feedback signal of the oxygen concentration sensor. An energy recovery system includes a burner connected to the pyrolysis zone via an insulated pipe for burning pyrolysis gas and generating high-temperature flue gas. The high-temperature flue gas generated by the burner is first connected to the heating jacket of the pyrolysis zone via an insulated pipe, and then connected to the heating jacket of the preheating zone. The sorting and recycling unit is used to sort and recycle the pyrolyzed photovoltaic laminates.

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