Gas recovery system and coating system

Abstract

This application discloses a gas recovery system and a coating system. The gas recovery system includes a tail gas conveying unit, a waste heat recovery unit, a cryogenic liquefaction unit, a storage unit, an adsorption separation unit, and an emission unit. The solution provided in this application combines the cryogenic liquefaction unit with the adsorption separation unit. The cryogenic liquefaction unit condenses the cooled solvent-containing tail gas, converting the organic solvent in the tail gas from a gaseous state to a liquid state and collecting it in the storage unit, thus achieving resource recovery of the organic solvent; simultaneously, it reduces waste gas emissions. Furthermore, after the initial solvent removal through cryogenic liquefaction, the tail gas concentration is reduced, and it then enters the adsorption zone of the adsorption separation unit for deep purification, allowing VOCs to be adsorbed. The purified tail gas is then emitted. The overall process is highly automated, the system operates stably and reliably, and it can operate synchronously with the coating system, meeting the requirements of continuous production.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a gas recovery system and a coating system. Background Technology

[0002] The lithium battery coating machine mainly consists of a coating section and an oven section. The oven section consumes a lot of heat energy to heat the air. The coating section is responsible for coating the prepared paste-like insulating slurry, which is dissolved in NMP as a solvent, onto the electrode substrate (copper foil or aluminum foil) as required. Then, the heater in the oven section heats the ambient air to a high temperature, so that the hot air dries the NMP solvent in the slurry coated on the electrode substrate. The remaining solid organic polymer forms a solid electrode layer on the electrode substrate, which is used to make lithium battery electrodes. The waste gas containing gaseous NMP is recovered by the recycling system before being discharged.

[0003] The recovery systems in related technologies are not suitable for the recovery of solvents with low boiling points. Utility Model Content

[0004] In view of the above problems, this application provides a gas recovery system and a coating system that can solve the problem that existing recovery systems are not suitable for recovering solvents with low boiling points.

[0005] To address the aforementioned technical problems, this application proposes a gas recovery system, comprising:

[0006] An exhaust gas conveying unit, wherein the input end of the exhaust gas conveying unit is connected to the exhaust gas outlet of the coating machine;

[0007] A waste heat recovery unit is connected to the output end of the exhaust gas conveying unit, and the waste heat recovery unit is configured to recover waste heat from the solvent-containing exhaust gas.

[0008] A cryogenic liquefaction unit, wherein the input end of the cryogenic liquefaction unit is connected to the output end of the waste heat recovery unit, and the cryogenic liquefaction unit is configured to cool the solvent-containing exhaust gas.

[0009] A storage unit, wherein the storage unit is connected to the drain port of the cryogenic liquefaction unit;

[0010] An adsorption separation unit, comprising an adsorption zone, wherein the input end of the adsorption separation unit is connected to the outlet of the cryogenic liquefaction unit;

[0011] The emission unit is connected to the outlet of the adsorption separation unit.

[0012] In the technical solution of this application embodiment, a cryogenic liquefaction unit is combined with an adsorption separation unit. The cryogenic liquefaction unit condenses the cooled solvent-containing exhaust gas, converting the organic solvent in the exhaust gas from a gaseous state to a liquid state and collecting it in a storage unit, thus realizing the resource recovery of organic solvents; at the same time, it reduces waste gas emissions. Moreover, after the exhaust gas undergoes preliminary solvent removal through cryogenic liquefaction, the waste gas concentration is reduced, and it then enters the adsorption zone of the adsorption separation unit for deep purification, so that VOCs are adsorbed by the adsorption zone, and the purified exhaust gas is then emitted. Furthermore, when the exhaust gas contains solvents with low boiling points, the combined action of the cryogenic liquefaction unit and the adsorption separation unit facilitates recovery. The overall process is highly automated, the system operates stably and reliably, and can operate synchronously with the coating system, meeting the requirements of continuous production. The waste heat recovery unit recovers heat from the high-temperature solvent-containing exhaust gas discharged from the coating machine, fully utilizing the waste heat in the exhaust gas, reducing overall system energy consumption, improving energy efficiency, and making it more energy-saving and environmentally friendly.

[0013] In some embodiments, the gas recovery system further includes a heating unit, a cooling unit, and a conveying fan;

[0014] The adsorption separation unit further includes a cooling zone and a desorption zone. Under the condition that the cooling zone is connected to the outlet of the cryogenic liquefaction unit, the solvent-containing tail gas passes through the cooling zone, the heating unit, the desorption zone, the conveying fan and the cooling unit in sequence, and is then conveyed to the input end of the cryogenic liquefaction unit.

[0015] In this way, when the solvent-containing exhaust gas enters the adsorption zone, under normal temperature conditions, the organic solvent molecules in the exhaust gas are adsorbed and retained by the zeolite molecular sieve, and the purified gas is discharged. The molecular sieve with adsorbed solvent enters the cooling zone with the rotor, where it is cooled by a normal temperature airflow to restore its adsorption activity. The cooled molecular sieve enters the desorption zone, where, under the action of the heating unit, the high-temperature airflow causes the adsorbed organic solvent to be desorbed and released, forming a high-concentration solvent waste gas, thus regenerating the molecular sieve. The regenerated molecular sieve re-enters the adsorption zone for the next cycle, thereby achieving continuous and stable exhaust gas adsorption purification and solvent desorption and recovery. At the same time, the high-concentration solvent waste gas formed is transported to the input end of the refrigeration unit for recycling after passing through the conveying fan and cooling unit.

[0016] In some embodiments, the gas recovery system further includes a waste heat recovery unit adapted to the waste heat recovery unit, the waste heat recovery unit being configured to deliver the heat recovered by the waste heat recovery unit to the coating machine.

[0017] In this way, the heat recovered from the exhaust gas of the coating machine by the waste heat recovery unit is sent back into the coating machine, so that the waste heat that was originally directly emitted can be effectively reused, reducing the energy consumption required for the coating machine to heat itself, improving energy efficiency, and making it more energy-saving and environmentally friendly.

[0018] In some embodiments, the gas recovery system further includes an air intake pretreatment unit connected to the air intake end of the waste heat recovery unit, the air intake pretreatment unit being configured to dehumidify the air entering the waste heat recovery unit.

[0019] In this way, by dehumidifying the air entering the waste heat recovery unit through the air intake pretreatment unit, the moisture content of the air can be effectively reduced, preventing condensation from forming when the humid air encounters cold air in the waste heat recovery unit or delivery pipelines. This avoids pipeline corrosion, equipment failure, or safety hazards caused by water accumulation. At the same time, the dehumidified dry hot air is sent into the coating machine, which can better adapt to the coating drying process requirements and prevent humid air from affecting the drying efficiency of the coating substrate and the coating quality.

[0020] In some embodiments, the gas recovery system further includes an evaporator and a condenser, which are sequentially disposed between the cryogenic liquefaction unit and the adsorption separation unit, and the drain outlet of the evaporator and the drain outlet of the condenser are respectively connected to the storage unit.

[0021] In this way, the residual solvent vapor in the exhaust gas that has not been initially condensed is further condensed into liquid by the evaporator. The liquid solvent then flows into the storage unit through its own drain port, realizing the secondary recovery of solvent. At the same time, the exhaust gas after being deeply cooled by the evaporator enters the condenser. After being treated by the condenser, the solvent content in the exhaust gas is reduced to an extremely low level, and then it enters the adsorption zone of the adsorption separation unit, which greatly improves the total solvent recovery rate of the entire system.

[0022] In some embodiments, the gas recovery system further includes a refrigeration unit connected between the evaporator and the condenser.

[0023] In this way, a low-temperature heat exchange environment is created inside the evaporator through the refrigeration cycle, which deeply cools and condenses the solvent-containing exhaust gas, allowing the residual organic solvent vapor in the exhaust gas to be fully liquefied. At the same time, the refrigeration unit, together with the condenser, realizes the circulation compression, condensation, throttling and evaporation of the refrigerant, ensuring a stable output of the cooling capacity of the entire deep condensation system. This enables the evaporator and condenser to continuously and efficiently perform staged condensation treatment of the exhaust gas, significantly improving the system's efficiency in recovering organic solvents.

[0024] In some embodiments, the gas recovery system further includes an inert gas protection unit;

[0025] The inert gas protection unit is connected to the storage unit, and the inert gas protection unit is configured to introduce inert gas into the storage unit.

[0026] In this way, by introducing inert gas into the storage unit, an inert gas protective layer can be formed inside the storage unit, effectively isolating external air from entering, thereby preventing the organic solvent volatile gas collected in the storage unit from mixing with air to form an explosive mixture.

[0027] In some embodiments, the inert gas protection unit includes a nitrogen source and a delivery pipeline;

[0028] One end of the conveying pipeline is connected to the nitrogen source, and the other end is connected to the storage unit. A pressure regulating valve is installed on the conveying pipeline.

[0029] In this way, the pressure of nitrogen entering the storage unit is regulated by the pressure regulating valve, so that the internal pressure of the storage unit is in a positive pressure state, which can effectively prevent air from entering and avoid damage to the storage unit caused by excessive pressure.

[0030] In some embodiments, the gas recovery system further includes a first controller and a pressure sensor, the pressure sensor being disposed in the storage unit, and the pressure sensor and the pressure regulating valve being electrically connected to the first controller respectively;

[0031] When the pressure sensor detects that the pressure inside the storage unit is lower than the nitrogen sealing pressure threshold, the first controller controls the pressure regulating valve to open.

[0032] When the pressure in the storage unit reaches a threshold, the first controller controls the pressure regulating valve to close.

[0033] This allows for easy detection of the pressure within the storage unit via a pressure sensor, while the first controller can easily control the opening and closing of the pressure regulating valve based on the corresponding pressure.

[0034] In some embodiments, the gas recovery system further includes a detection element and a second controller, wherein the detection element and the exhaust gas delivery unit are electrically connected to the second controller, respectively;

[0035] The detection element is configured to detect the temperature of the liquid stored inside the cryogenic liquefaction unit;

[0036] When the coating machine is in standby mode and the liquid temperature exceeds the threshold, the second controller controls the exhaust gas delivery unit to start.

[0037] In this way, when the coating machine is in standby or the system is shut down, the temperature of the liquid inside the cryogenic liquefaction unit is monitored in real time by the detection device. When the temperature exceeds the threshold, the exhaust gas delivery unit is automatically started. This can effectively prevent the large amount of organic solvent from evaporating and the solvent concentration in the system from exceeding the standard due to excessive liquid temperature, thereby reducing the risk of combustion, explosion and leakage from the source and significantly improving the safety and reliability of the system during standby.

[0038] This application also proposes a coating system including a gas recovery system as described in any one of the embodiments of this application.

[0039] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments described below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0041] Figure 1 This is a schematic diagram of a gas recovery system provided in some embodiments of this application.

[0042] The reference numerals in the detailed embodiments are as follows:

[0043] 1. Coating machine; 2. Exhaust gas conveying unit; 3. Waste heat recovery unit; 4. Refrigeration liquefaction unit; 5. Evaporator; 6. Condenser; 7. Adsorption separation unit; 8. Heating unit; 9. Discharge unit; 10. Cooling unit; 11. Conveying fan; 12. Refrigeration unit; 121. Compressor; 122. Expansion valve; 13. Waste heat recovery unit; 14. Inlet pretreatment unit; 15. Material storage unit. Detailed Implementation

[0044] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0046] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0047] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0048] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0049] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0050] In the description of the embodiments of this application, the technical 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 only for the convenience of describing the embodiments of this application 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 the embodiments of this application.

[0051] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" 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 or an electrical connection; 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0052] The lithium battery coating machine mainly consists of a coating section and an oven section. The oven section consumes a lot of heat energy to heat the air. The coating section is responsible for coating the prepared paste-like insulating slurry, which is dissolved in NMP as a solvent, onto the electrode substrate (copper foil or aluminum foil) as required. Then, the heater in the oven section heats the ambient air to a high temperature, so that the hot air dries the NMP solvent in the slurry coated on the electrode substrate. The remaining solid organic polymer forms a solid electrode layer on the electrode substrate, which is used to make lithium battery electrodes. The waste gas containing gaseous NMP is recovered by the recycling system before being discharged.

[0053] The recovery systems in related technologies cannot recover solvents with low boiling points during use.

[0054] Based on the above considerations, in order to solve the problem that the recovery system cannot recover solvents with low boiling points during use, this application designs a gas recovery system. The gas recovery system includes a tail gas conveying unit, a waste heat recovery unit, a cryogenic liquefaction unit, a storage unit, an adsorption separation unit, and an emission unit. The input end of the tail gas conveying unit is connected to the tail gas outlet of the coating machine, the waste heat recovery unit is connected to the output end of the tail gas conveying unit, and the waste heat recovery unit is configured to recover waste heat from the solvent-containing tail gas. The input end of the cryogenic liquefaction unit is connected to the output end of the waste heat recovery unit, and the cryogenic liquefaction unit is configured to cool the solvent-containing tail gas. The storage unit is connected to the discharge port of the cryogenic liquefaction unit. The adsorption separation unit includes an adsorption zone, the input end of the adsorption separation unit is connected to the gas outlet of the cryogenic liquefaction unit, and the emission unit is connected to the gas outlet of the adsorption separation unit.

[0055] In the technical solution of this application embodiment, a cryogenic liquefaction unit is combined with an adsorption separation unit. The cryogenic liquefaction unit condenses the cooled solvent-containing exhaust gas, converting the organic solvent in the exhaust gas from a gaseous state to a liquid state and collecting it in a storage unit, thus realizing the resource recovery of organic solvents; at the same time, it reduces waste gas emissions. Moreover, after the exhaust gas undergoes preliminary solvent removal through cryogenic liquefaction, the waste gas concentration is reduced, and it then enters the adsorption zone of the adsorption separation unit for deep purification, so that VOCs are adsorbed by the adsorption zone, and the purified exhaust gas is then emitted. Furthermore, when the exhaust gas contains solvents with low boiling points, the combined action of the cryogenic liquefaction unit and the adsorption separation unit facilitates recovery. The overall process is highly automated, the system operates stably and reliably, and can operate synchronously with the coating system, meeting the requirements of continuous production. The waste heat recovery unit recovers heat from the high-temperature solvent-containing exhaust gas discharged from the coating machine, fully utilizing the waste heat in the exhaust gas, reducing overall system energy consumption, improving energy efficiency, and making it more energy-saving and environmentally friendly.

[0056] According to some embodiments of this application, such as Figure 1 As shown, this application provides a gas recovery system, which includes a tail gas conveying unit 2, a waste heat recovery unit 3, a cryogenic liquefaction unit 4, a storage unit 15, an adsorption separation unit 7, and an emission unit 9. The input end of the tail gas conveying unit 2 is connected to the tail gas outlet of the coating machine 1. The waste heat recovery unit 3 is connected to the output end of the tail gas conveying unit 2 and is configured to recover waste heat from the solvent-containing tail gas. The input end of the cryogenic liquefaction unit 4 is connected to the output end of the waste heat recovery unit 3 and is configured to cool the solvent-containing tail gas. The storage unit 15 is connected to the discharge port of the cryogenic liquefaction unit 4. The adsorption separation unit 7 includes an adsorption zone. The input end of the adsorption separation unit 7 is connected to the outlet of the cryogenic liquefaction unit 4, and the emission unit 9 is connected to the outlet of the adsorption separation unit 7.

[0057] In this embodiment, the exhaust gas conveying unit 2 can be an exhaust fan, the waste heat recovery unit 3 can be a waste heat recovery heat pump unit, the refrigeration liquefaction unit 4 can be a refrigeration surface cooler, the storage unit 15 can be a storage tank, the adsorption separation unit 7 can be a zeolite molecular sieve rotor, and the emission unit 9 can be an external exhaust fan. The specifics can be determined according to the actual situation, and this embodiment does not limit them.

[0058] In this embodiment, the exhaust outlet of the coating machine 1, the exhaust gas conveying unit 2, the waste heat recovery unit 3, the cryogenic liquefaction unit 4, the adsorption separation unit 7, and the discharge unit 9 are sequentially connected by pipelines. Simultaneously, the discharge port of the cryogenic liquefaction unit 4 is also connected to the storage unit 15 via a pipeline.

[0059] In operation, the cryogenic liquefaction unit 4 is combined with the adsorption separation unit 7. The cryogenic liquefaction unit 4 condenses the cooled solvent-containing exhaust gas, converting the organic solvent in the exhaust gas from a gaseous state to a liquid state and collecting it in the storage unit 15, thus achieving resource recovery of the organic solvent and reducing waste gas emissions. Furthermore, after the initial solvent removal through cryogenic liquefaction, the exhaust gas concentration is reduced, and it then enters the adsorption zone of the adsorption separation unit 7 for deep purification, allowing VOCs to be adsorbed. The purified exhaust gas is then discharged. Simultaneously, when the exhaust gas contains solvents with low boiling points, the combined action of the cryogenic liquefaction unit and the adsorption separation unit facilitates recovery. The overall process is highly automated, the system operates stably and reliably, and can operate synchronously with the coating system, meeting the requirements of continuous production. Moreover, the waste heat recovery unit 3 recovers heat from the high-temperature solvent-containing exhaust gas discharged from the coating machine 1, fully utilizing the waste heat in the exhaust gas, reducing overall system energy consumption, improving energy efficiency, and making it more energy-saving and environmentally friendly.

[0060] According to some embodiments of this application, such as Figure 1 As shown, the gas recovery system also includes a heating unit 8, a cooling unit 10, and a conveying fan 11. The adsorption separation unit 7 further includes a cooling zone and a desorption zone. Under the condition that the cooling zone is connected to the gas outlet of the refrigeration liquefaction unit 4, the solvent-containing tail gas passes through the cooling zone, heating unit 8, desorption zone, conveying fan 11, and cooling unit 10 in sequence before being conveyed to the input end of the refrigeration liquefaction unit 4.

[0061] In this embodiment, the heating unit 8 can be a heat source, heating wire, etc., and the cooling unit 10 can be a cooler, etc., which is not limited here.

[0062] In this embodiment, the adsorption separation unit 7 is a zeolite molecular sieve rotor. When solvent-containing exhaust gas enters the adsorption zone, under normal temperature conditions, the organic solvent molecules in the exhaust gas are adsorbed and retained by the zeolite molecular sieve, and the purified gas is discharged. The molecular sieve with adsorbed solvent enters the cooling zone with the rotor, where it is cooled by a normal temperature airflow to restore its adsorption activity. The cooled molecular sieve enters the desorption zone, where, under the action of the heating unit 8, a high-temperature airflow causes the adsorbed organic solvent to be desorbed and released, forming a high-concentration solvent waste gas, thus regenerating the molecular sieve. The regenerated molecular sieve re-enters the adsorption zone for the next cycle, thereby achieving continuous and stable exhaust gas adsorption purification and solvent desorption and recovery. At the same time, the formed high-concentration solvent waste gas is transported to the input end of the cryogenic liquefaction unit 4 for recycling after passing through the conveying fan 11 and the cooling unit 10.

[0063] According to some embodiments of this application, such as Figure 1As shown, the gas recovery system also includes a waste heat recovery unit 13, which is adapted to the waste heat recovery unit 3. The waste heat recovery unit 13 is configured to transfer the heat recovered by the waste heat recovery unit 3 to the coating machine 1.

[0064] In this embodiment, the waste heat recovery unit 13 can be a fan, which is not limited here.

[0065] During use, the heat recovered from the exhaust gas of the coating machine 1 by the waste heat recovery unit 3 is sent back into the coating machine 1 through the waste heat recovery unit 13, so that the waste heat that was originally directly emitted can be effectively reused, reducing the energy consumption required for the coating machine 1 to heat itself, improving energy utilization, and making it more energy-saving and environmentally friendly.

[0066] According to some embodiments of this application, such as Figure 1 As shown, the gas recovery system also includes an air intake pretreatment unit 14, which is connected to the air intake end of the waste heat recovery unit 13. The air intake pretreatment unit 14 is configured to dehumidify the air entering the waste heat recovery unit 13.

[0067] In this embodiment, the air intake pretreatment unit 14 can be a dehumidifier, which is not limited here.

[0068] During operation, the air entering the waste heat recovery unit 13 is dehumidified by the air intake pretreatment unit 14, which effectively reduces the air moisture content and prevents condensation from forming in the waste heat recovery unit 3 or the delivery pipeline. This avoids pipeline corrosion, equipment failure, or safety hazards caused by water accumulation. Simultaneously, the dehumidified dry hot air is sent into the coating machine 1, better meeting the requirements of the coating and drying process and preventing the introduction of humid air that could affect the drying efficiency and coating quality of the substrate.

[0069] According to some embodiments of this application, such as Figure 1 As shown, the gas recovery system also includes an evaporator 5 and a condenser 6. The evaporator 5 and the condenser 6 are arranged sequentially between the cryogenic liquefaction unit 4 and the adsorption separation unit 7, and the drain outlet of the evaporator 5 and the drain outlet of the condenser 6 are respectively connected to the storage unit 15.

[0070] In this embodiment, the cryogenic liquefaction unit 4, evaporator 5, condenser 6 and adsorption separation unit 7 are connected in sequence by pipes. At the same time, the drain outlet of evaporator 5 and the drain outlet of condenser 6 are respectively connected to the storage unit 15 by pipes.

[0071] In use, the evaporator 5 further condenses the residual solvent vapor in the exhaust gas that has not been initially condensed into liquid. The liquid solvent then flows into the storage unit 15 through its own drain port, realizing secondary solvent recovery. At the same time, the exhaust gas after being deeply cooled by the evaporator 5 enters the condenser 6. After being treated by the condenser 6, the solvent content in the exhaust gas is reduced to an extremely low level, and then it enters the adsorption zone of the adsorption separation unit 7, which greatly improves the total solvent recovery rate of the entire system.

[0072] According to some embodiments of this application, such as Figure 1 As shown, the gas recovery system also includes a refrigeration unit 12, which is connected between the evaporator 5 and the condenser 6.

[0073] The refrigeration unit 12 in this embodiment includes a compressor 121 and an expansion valve 122, wherein the evaporator 5, compressor 121, condenser 6, and expansion valve 122 are sequentially connected in a cycle. The specific working principles of the compressor 121 and expansion valve 122 can be found in the section on compressors and expansion valves in refrigeration machines, and will not be elaborated here.

[0074] During operation, a low-temperature heat exchange environment is created inside the evaporator 5 through a refrigeration cycle, which deeply cools and condenses the solvent-containing exhaust gas, allowing the residual organic solvent vapor in the exhaust gas to be fully liquefied. At the same time, the refrigeration unit 12, in conjunction with the condenser 6, realizes the circulation compression, condensation, throttling and evaporation of the refrigerant, ensuring a stable output of the refrigeration capacity of the entire deep condensation system. This enables the evaporator 5 and condenser 6 to continuously and efficiently perform staged condensation treatment on the exhaust gas, significantly improving the system's efficiency in recovering organic solvents.

[0075] According to some embodiments of this application, the gas recovery system further includes an inert gas protection unit; the inert gas protection unit is connected to the storage unit 15 and is configured to introduce inert gas into the storage unit 15.

[0076] In this embodiment, the inert gas protection unit can be nitrogen, and there is no limitation here.

[0077] In use, by introducing inert gas into the storage unit 15, an inert gas protective layer can be formed inside the storage unit 15, effectively isolating external air from entering, thereby preventing the organic solvent volatile gas collected in the storage unit 15 from mixing with air to form an explosive mixture.

[0078] According to some embodiments of this application, the inert gas protection unit includes a nitrogen source and a delivery pipeline; wherein, one end of the delivery pipeline is connected to the nitrogen source and the other end is connected to the storage unit 15, and a pressure regulating valve is provided on the delivery pipeline.

[0079] During use, the pressure of nitrogen entering the storage unit 15 is adjusted by the pressure regulating valve to keep the internal pressure of the storage unit 15 in a positive pressure state, which can effectively prevent air from entering and avoid damage to the storage unit 15 due to excessive pressure.

[0080] According to some embodiments of this application, the gas recovery system further includes a first controller and a pressure sensor, wherein the pressure sensor is disposed in the storage unit 15, and the pressure sensor and the pressure regulating valve are electrically connected to the first controller respectively; when the pressure sensor detects that the pressure in the storage unit 15 is lower than the nitrogen sealing pressure threshold, the first controller controls the pressure regulating valve to open; when the pressure in the storage unit 15 reaches the threshold, the first controller controls the pressure regulating valve to close.

[0081] In this embodiment, the threshold can be 0-5Pa, and the first controller can be a PLC controller. The specific controller can be determined according to the actual situation, and this embodiment does not limit it.

[0082] During use, the pressure inside the storage unit 15 can be easily detected by the pressure sensor. At the same time, the first controller can easily control the opening and closing of the pressure regulating valve according to the corresponding pressure.

[0083] According to some embodiments of this application, the gas recovery system further includes a detection element and a second controller, wherein the detection element and the exhaust gas delivery unit 2 are electrically connected to the second controller respectively; the detection element is configured to detect the temperature of the liquid stored inside the cryogenic liquefaction unit 4; when the coating machine 1 is in standby mode and the liquid temperature exceeds a threshold, the second controller controls the exhaust gas delivery unit 2 to start.

[0084] In this embodiment, the detection device can be a temperature sensor, and the threshold temperature of the liquid can be between 8℃ and 11℃. The specific temperature can be determined according to the actual situation, and this embodiment does not limit it.

[0085] When in use, the temperature of the liquid inside the cryogenic liquefaction unit 4 is monitored in real time by the detection device when the coating machine 1 is in standby or the system is stopped. When the temperature exceeds the threshold, the exhaust gas delivery unit 2 is automatically started. This can effectively prevent the liquid temperature from being too high, which can lead to a large amount of organic solvent volatilization and excessive solvent concentration in the system. This reduces the risk of combustion, explosion and leakage from the source and significantly improves the safety and reliability of the system during standby.

[0086] This application also proposes a coating system including a gas recovery system as described in any of the embodiments of this application.

[0087] The specific structure of the gas recovery system in this embodiment is the same as that in the above embodiments. Since the coating system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A gas recovery system, characterized in that, include: An exhaust gas conveying unit, wherein the input end of the exhaust gas conveying unit is connected to the exhaust gas outlet of the coating machine; A waste heat recovery unit is connected to the output end of the exhaust gas conveying unit, and the waste heat recovery unit is configured to recover waste heat from the solvent-containing exhaust gas. A cryogenic liquefaction unit, wherein the input end of the cryogenic liquefaction unit is connected to the output end of the waste heat recovery unit, and the cryogenic liquefaction unit is configured to cool the solvent-containing exhaust gas. A storage unit, wherein the storage unit is connected to the drain port of the cryogenic liquefaction unit; An adsorption separation unit, comprising an adsorption zone, wherein the input end of the adsorption separation unit is connected to the outlet of the cryogenic liquefaction unit; The emission unit is connected to the outlet of the adsorption separation unit.

2. The gas recovery system according to claim 1, characterized in that, The gas recovery system also includes a heating unit, a cooling unit, and a conveying fan; The adsorption separation unit further includes a cooling zone and a desorption zone. Under the condition that the cooling zone is connected to the outlet of the cryogenic liquefaction unit, the solvent-containing tail gas passes through the cooling zone, the heating unit, the desorption zone, the conveying fan and the cooling unit in sequence, and is then conveyed to the input end of the cryogenic liquefaction unit.

3. The gas recovery system according to claim 1, characterized in that, The gas recovery system also includes a waste heat recovery unit adapted to the waste heat recovery unit, which is configured to transfer the heat recovered by the waste heat recovery unit to the coating machine.

4. The gas recovery system according to claim 3, characterized in that, The gas recovery system further includes an air intake pretreatment unit, which is connected to the air intake end of the waste heat recovery unit. The air intake pretreatment unit is configured to dehumidify the air entering the waste heat recovery unit.

5. The gas recovery system according to claim 1, characterized in that, The gas recovery system also includes an evaporator and a condenser, which are sequentially arranged between the cryogenic liquefaction unit and the adsorption separation unit, and the drain outlet of the evaporator and the drain outlet of the condenser are respectively connected to the storage unit.

6. The gas recovery system according to claim 5, characterized in that, The gas recovery system also includes a refrigeration unit connected between the evaporator and the condenser.

7. The gas recovery system according to any one of claims 1 to 6, characterized in that, The gas recovery system also includes an inert gas protection unit; The inert gas protection unit is connected to the storage unit, and the inert gas protection unit is configured to introduce inert gas into the storage unit.

8. The gas recovery system according to claim 7, characterized in that, The inert gas protection unit includes a nitrogen source and a delivery pipeline; One end of the conveying pipeline is connected to the nitrogen source, and the other end is connected to the storage unit. A pressure regulating valve is installed on the conveying pipeline.

9. The gas recovery system according to claim 8, characterized in that, The gas recovery system further includes a first controller and a pressure sensor. The pressure sensor is disposed in the storage unit, and the pressure sensor and the pressure regulating valve are electrically connected to the first controller. When the pressure sensor detects that the pressure inside the storage unit is lower than the nitrogen sealing pressure threshold, the first controller controls the pressure regulating valve to open. When the pressure in the storage unit reaches a threshold, the first controller controls the pressure regulating valve to close.

10. The gas recovery system according to any one of claims 1 to 6, characterized in that, The gas recovery system further includes a detection element and a second controller, wherein the detection element and the exhaust gas delivery unit are electrically connected to the second controller. The detection element is configured to detect the temperature of the liquid stored inside the cryogenic liquefaction unit; When the coating machine is in standby mode and the liquid temperature exceeds the threshold, the second controller controls the exhaust gas delivery unit to start.

11. A coating system, characterized in that, Includes the gas recovery system as described in any one of claims 1 to 10.

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