Organic gas recovery purifier

Abstract

The application provides an organic gas recovery and purification device, which comprises a waste gas source, a heat exchange assembly, a condensation assembly, an absorption and distillation tower, an air outlet circuit and an air return circuit. The air outlet circuit comprises a gas path from the gas outlet of the waste gas source to the gas inlet of the condensation assembly through the heat exchange assembly. The air return circuit comprises a gas path from the gas outlet of the condensation assembly to the gas inlet of the waste gas source through the heat exchange assembly. The gas outlet of the waste gas source is communicated with the first inlet of the heat exchange assembly. The first outlet of the heat exchange assembly is communicated with the gas inlet of the condensation assembly. The gas outlet of the condensation assembly is communicated with the second inlet of the heat exchange assembly. The second outlet of the heat exchange assembly is communicated with the gas inlet of the waste gas source. The gas inlet arranged at the bottom of the absorption and distillation tower is communicated with the air outlet circuit or the air return circuit. The temperature of the gas entering the gas inlet of the absorption and distillation tower is 60-80 DEG C. The application can fully utilize the heat energy of the gas discharged from the waste gas source, so that the gas discharged from the absorption and distillation tower is thoroughly purified and meets the emission standard.

Description

Technical Field

[0001] This application relates to the field of waste gas recovery and treatment technology, and in particular to an organic gas recovery and purification device. Background Technology

[0002] Coating ovens are crucial equipment in the manufacturing processes of lithium batteries and other products. During operation, they generate high-temperature N-methylpyrrolidone (NMP) waste gases. NMP is costly, harmful to human health, and poses safety risks in production. Direct emission of NMP not only pollutes the environment but also wastes energy. Therefore, it is essential to recycle and treat the NMP waste gases generated during production to achieve compliant emissions.

[0003] The existing process for recovering NMP waste gas generated by the coating machine oven typically involves first passing the NMP waste gas through a heat exchanger into a condensation recovery device for condensation recovery. After condensation recovery, part of the gas is passed into the treatment zone of the adsorption rotor for adsorption treatment before being discharged, part is passed into the cooling zone of the adsorption rotor for cooling treatment, and another part is passed back into the coating machine oven through a heat exchanger. However, both the coating machine oven itself and the regeneration zone of the adsorption rotor require heating components to heat the gas into them to their set temperature. Therefore, a large amount of external heat energy is required for normal operation during the process, and the above method cannot guarantee that the emitted gas can meet the emission requirements.

[0004] Therefore, how to save energy required in the waste gas recovery and treatment process as much as possible, and how to ensure that the emitted gas meets emission requirements, has become an urgent problem for those skilled in the art. Summary of the Invention

[0005] In order to solve one or more of the technical problems existing in the prior art, the present application provides a new organic gas recovery and purification device. Compared with the prior art, it can make full use of the heat energy of the gas discharged from the waste gas source, so that the gas discharged from the absorption distillation tower is thoroughly purified and meets the emission standards.

[0006] To achieve the above objectives, the technical solution adopted by this application to solve its technical problem is as follows:

[0007] This application provides an organic gas recovery and purification device, which includes a waste gas source, a heat exchange component, a condensation component, an absorption distillation tower, an exhaust air circuit, and a return air circuit.

[0008] The air outlet circuit includes an air path from the outlet of the exhaust gas source through the heat exchange component to the inlet of the condensation component.

[0009] The return air circuit includes an air path from the outlet of the condenser assembly through the heat exchange assembly to the inlet of the exhaust gas source.

[0010] The outlet of the exhaust gas source is connected to the first inlet of the heat exchange component, the first outlet of the heat exchange component is connected to the inlet of the condensation component, the outlet of the condensation component is connected to the second inlet of the heat exchange component, the second outlet of the heat exchange component is connected to the inlet of the exhaust gas source, and the inlet of the absorption distillation tower is connected to the air outlet circuit or the air return circuit.

[0011] The absorption distillation tower includes a distillation section and an absorption section arranged sequentially along the gas flow direction. The gas inlet is located in the distillation section, and the temperature of the gas entering the gas inlet of the absorption distillation tower is 60-80℃.

[0012] This application achieves the distillation and concentration of the absorbent in the stripping section by automatically adjusting the flow rates of two gases at different temperatures entering the absorption and stripping tower, thereby maintaining the gas temperature in the tower within the range of 60-80°C.

[0013] Preferably, the temperature of the gas entering the inlet of the absorption distillation tower is 65-75°C.

[0014] In one specific embodiment, the stripping section includes a first spraying mechanism, a first absorption mechanism, and a first medium circulation path;

[0015] The first medium circulation path includes a drain port, a circulation pump, and a liquid inlet. The inlet of the circulation pump is connected to the drain port, the outlet of the circulation pump is connected to the liquid inlet, and the liquid inlet is connected to the first spraying mechanism. The first absorption mechanism enables the gas to fully contact the first medium.

[0016] In one specific embodiment, the outlet of the circulating pump is provided with a branch pipeline, which is connected to an intermediate storage tank for the concentrated absorbent.

[0017] In one specific embodiment, the organic gas recovery and purification device is characterized in that the absorption section includes a second spraying mechanism, a second absorption mechanism, a second medium flow path, and an exhaust port;

[0018] The second spraying mechanism is connected to the second medium flow path, and the second absorption mechanism ensures that the gas and the second medium are in full contact.

[0019] In one specific embodiment, after being sprayed, the flow direction of the first medium and / or the second medium in the absorption distillation tower forms an angle of 90-180° with the gas flow direction.

[0020] In one specific embodiment, the stripping section and the absorption section are arranged in a vertical direction.

[0021] In one specific embodiment, the device further includes a concentration sensor for detecting the concentration of the first medium and an automatic regulating solenoid valve. The concentration sensor is disposed between the circulating pump and the inlet, and the automatic regulating solenoid valve is disposed on the branch pipeline.

[0022] In one specific embodiment, the outlet of the condensation component and the second outlet of the heat exchange component are both connected to the inlet of the absorption distillation tower. The gas treated by the condensation component is mixed with the gas from the heat exchange component and then enters the absorption distillation tower.

[0023] In one specific embodiment, the outlet of the waste gas source and the first outlet of the heat exchange component are both connected to the inlet of the absorption distillation tower. The gas from the waste gas source and the gas from the heat exchange component are mixed and then enter the absorption distillation tower.

[0024] In one specific embodiment, the condensation assembly includes a cooling water coil and a chilled water coil. The air inlet of the cooling water coil is connected to the first outlet of the heat exchange assembly, the air outlet of the cooling water coil is connected to the air inlet of the chilled water coil, and the air outlet of the chilled water coil is connected to at least the second inlet of the heat exchange assembly.

[0025] In one specific embodiment, the device further includes:

[0026] A first fan, the air inlet of which is connected to the air outlet of the condensation assembly, and the air outlet of which is connected to the second inlet of the heat exchange assembly; and / or,

[0027] The second fan has its inlet connected to the outlet air circuit or the return air circuit, and its outlet connected to the inlet of the absorption distillation tower.

[0028] In one specific embodiment, the exhaust gas source is a coating machine oven.

[0029] The beneficial effects of the technical solutions provided in this application are:

[0030] The organic gas recovery and purification device provided in this application includes a waste gas source, a heat exchange component, a condensation component, an absorption distillation tower, an outlet air circuit, and a return air circuit. The outlet air circuit includes a gas path from the outlet of the waste gas source through the heat exchange component to the inlet of the condensation component. The return air circuit includes a gas path from the outlet of the condensation component through the heat exchange component to the inlet of the waste gas source. The outlet of the waste gas source is connected to the first inlet of the heat exchange component, the first outlet of the heat exchange component is connected to the inlet of the condensation component, the outlet of the condensation component is connected to the second inlet of the heat exchange component, the second outlet of the heat exchange component is connected to the inlet of the waste gas source, and the inlet of the absorption distillation tower is connected to either the outlet air circuit or the return air circuit. The absorption distillation tower includes a distillation section and an absorption section arranged sequentially along the gas flow direction. The inlet is located in the distillation section, and the temperature of the gas entering the inlet of the absorption distillation tower is 60-80°C. This application can fully utilize the thermal energy of the gas discharged from the waste gas source, so that the gas discharged from the absorption distillation tower can be thoroughly purified and meet the emission standards.

[0031] Furthermore, this application introduces a high-temperature mixed gas into the bottom of an absorption distillation tower. Simultaneously, absorbent (including a first medium and a second medium) sprayed from the upper spraying mechanism is sprayed onto the surface of the absorption mechanism. As the liquid flows downwards, it comes into countercurrent contact with the high-temperature gas introduced from the bottom of the tower, heating the mixed liquid. This causes the low-boiling-point substance, water, in the mixed liquid to continuously evaporate into water vapor, rising upwards in the tower, ultimately resulting in a high-boiling-point concentrated NMP solution at the bottom. Simultaneously, during this contact distillation process, since the latent heat of vaporization required for water evaporation is entirely absorbed by the sensible heat of the high-temperature gas, the gas temperature after this distillation section has decreased to a level sufficient for the absorption operation in the upper absorption section. The pure water absorbent sprayed at the top of the tower can absorb almost all the remaining NMP in the rising gas, ensuring that the gas discharged from the top of the tower is thoroughly purified, meets emission standards, and is released into the atmosphere. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the organic gas recovery and purification device provided in Embodiment 1 of this application;

[0034] Figure 2 It is the relationship between the evaporation rate of water and temperature;

[0035] Figure 3 This is the relationship between the evaporation rate of NMP and temperature;

[0036] Figure 4 This is a schematic diagram of the organic gas recovery and purification device provided in Embodiment 2 of this application. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0039] The organic gas recovery and purification device of this application generally includes a waste gas source 100, a heat exchange component 200, a condensation component 300, an absorption distillation tower 400, an outlet air circuit, and a return air circuit. The waste gas source 100 includes, but is not limited to, a coating machine oven, and the waste gas discharged from the waste gas source includes, but is not limited to, NMP. The outlet air circuit includes a gas path from the outlet of the waste gas source 100 through the heat exchange component 200 to the inlet of the condensation component 300. The return air circuit includes a gas path from the outlet of the condensation component 300 through the heat exchange component 200 to the inlet of the waste gas source 100. The outlet of the waste gas source 100 is connected to the first inlet 210 of the heat exchange component 200, and the first inlet 210 of the heat exchange component 200... An outlet 220 is connected to the inlet of the condenser assembly 300, the outlet of the condenser assembly 300 is connected to the second inlet 230 of the heat exchange assembly 200, the second outlet 240 of the heat exchange assembly 200 is connected to the inlet of the waste gas source 100, and the inlet of the absorption distillation tower is connected to the outlet air circuit or the return air circuit; the absorption distillation tower includes a distillation section and an absorption section arranged sequentially along the gas flow direction, the inlet is located in the distillation section, and the temperature of the gas entering the inlet of the absorption distillation tower is 60-80℃.

[0040] A coating machine oven typically consists of several oven units, each interconnected. The substrate being coated moves forward in the same direction within the oven, continuously subjected to high-temperature baking within each oven unit during its movement, and is then dried.

[0041] For ease of description, the exhaust gas source in each of the following preferred embodiments is a coating machine oven, and the exhaust gas is NMP. However, it should be understood that the exhaust gas source described in this application is not limited to the coating machine oven. Any production device that generates organic gases or other exhaust gases during production and requires ventilation, such as lithium battery coating ovens, printing, semiconductor, and adhesive tape manufacturing, can use the solution of this application. The coating machine oven should not be construed as a limitation on the exhaust gas source in this application, and NMP should also not be construed as a limitation on the exhaust gas in this application. Other coating-related organic gases, such as toluene, N,N-dimethylacetamide (DMAC), and N,N-dimethylformamide (DMF), can also be recovered and treated using the organic gas recovery and treatment system of this application.

[0042] Example 1

[0043] Figure 1 This is a schematic diagram of the organic gas recovery and purification device provided in Embodiment 1 of this application, with reference to... Figure 1 As shown, the organic gas recovery and treatment device generally includes a waste gas source 100, a heat exchange assembly 200, a condensation assembly 300, an absorption distillation tower 400, an outlet air circuit, and a return air circuit. The outlet air circuit includes a gas path from the outlet of the waste gas source 100 through the heat exchange assembly 200 to the inlet of the condensation assembly 300. The return air circuit includes a gas path from the outlet of the condensation assembly 300 through the heat exchange assembly 200 to the inlet of the waste gas source 100.

[0044] The absorption and stripping tower 400 in this embodiment is mainly divided into two parts: an absorption section and a stripping section, arranged sequentially along the gas flow direction. The absorption section and stripping section are arranged vertically. The upper absorption section mainly performs the function of an absorption tower, absorbing waste gas from the mixed gas entering the tower. The lower stripping section mainly performs the function of a stripping tower, stripping the waste gas. The absorption operation refers to the process of converting the absorbent (such as NMP) from the gas phase to the liquid phase. This mainly utilizes the different solubilities of gas components in the absorbent liquid (usually called the absorbent) to separate a certain component (called the absorbent) from other components in the gas mixture. An absorption tower is a gas-liquid mass transfer device used for absorption operations. The tower provides a sufficiently large contact area (packing or trays) and contact time for the gas and liquid to interact. The absorbent is added from the top and uniformly dispersed on the packing surface, flowing downwards. Simultaneously, the gas is introduced from the bottom and flows counter-currently upwards, contacting the liquid. During this contact process, the absorbent (such as NMP) is continuously absorbed into the absorbent. The purified gas exits from the top, and the liquid that has absorbed the absorbent exits from the bottom. For a physical absorption process, since low temperatures favor gas absorption while high temperatures cause desorption of the absorbent from the absorbent, absorption operations typically need to be carried out at relatively low temperatures. Conversely, distillation refers to the gas-liquid mass transfer process that occurs in the lower section of a distillation tower. It mainly utilizes the difference in evaporation and condensation temperatures of the components in a liquid mixture. Through repeated heating and condensation of the liquid mixture, the low-boiling-point liquid continuously evaporates into gas and moves towards the top of the tower, while the high-boiling-point liquid is continuously concentrated and flows towards the bottom, thereby increasing the concentration of the high-boiling-point liquid.

[0045] To achieve the above-mentioned absorption and distillation functions, further refer to Figure 1As shown, in a preferred embodiment of this application, the absorption and distillation column 400 includes a column body 410, with an absorption section disposed in the upper half of the column body 410 and a stripping section disposed in the lower half of the column body 410. An air inlet 470 is disposed at the bottom of the column body 410 corresponding to the stripping section. The stripping section includes a first spray mechanism 420, a first absorption mechanism 430, and a first medium circulation path. The first spray mechanism 420 and the first absorption mechanism 430 are arranged from top to bottom inside the column body 410 corresponding to the stripping section. The first medium circulation path includes a drain port 450, an inlet port 460, and a circulation pump 500. The drain port 450 is located at the bottom of the column body 410 corresponding to the stripping section, away from the air inlet 470 of the absorption and distillation column. The inlet port 460 is disposed on the column body 410 corresponding to the stripping section and located above the first absorption mechanism 430. A circulating pump 500 is disposed between a drain port 450 and an inlet port 460. The inlet of the circulating pump 500 is connected to the drain port 450, and the outlet of the circulating pump 500 is connected to the inlet port 460. The inlet port 460 is connected to the first spraying mechanism 420. The first absorption mechanism 430 enables the gas to come into full contact with the first medium, which includes, but is not limited to, a solution containing NMP.

[0046] The absorption section includes a second spraying mechanism 480, a second absorption mechanism 490, a second medium flow path, and an exhaust port 440. The second spraying mechanism 480 and the second absorption mechanism 490 are arranged from top to bottom inside the corresponding tower body 410 of the absorption section, and the exhaust port 440 is located at the top of the corresponding tower body 410. The second spraying mechanism 480 is connected to an external medium source (not shown) and is used to spray a second medium (including but not limited to pure water) from the external medium source from top to bottom within the tower body 410, so that the second medium is sprayed onto the surface of the second absorption mechanism 490.

[0047] In operation, the second spraying mechanism 480 sprays the second medium from an external medium source into the tower body 410 from top to bottom, causing the second medium to be sprayed onto the surface of the second absorption mechanism 490 and continue to be sprayed downwards onto the surface of the first absorption mechanism 430. Simultaneously, the first spraying mechanism 420 sprays a solution containing NMP (i.e., the first medium) from the liquid inlet 460 onto the surface of the first absorption mechanism 430, mixing it with the second medium to form a mixed liquid. High-temperature gas entering through the gas inlet 470 of the absorption distillation tower is introduced from bottom to top within the tower body 410, making countercurrent contact with the mixed liquid on the first absorption mechanism 430 to further purify the mixed liquid. The mixture is heated, causing the low-boiling-point substances in the mixture to continuously evaporate into water vapor and rise to the top of the column. Eventually, a high-boiling-point NMP concentrated solution is obtained at the bottom of the column. At the same time, during this contact distillation process, since the latent heat of vaporization required for water evaporation is entirely absorbed by the sensible heat of the high-temperature gas, the gas temperature after this distillation section has been reduced to a temperature that meets the absorption operation requirements of the upper absorption section. The second medium sprayed at the top of the column can absorb almost all the remaining NMP in the rising gas, so that the gas discharged from the exhaust port 440 at the top of the column is thoroughly purified, meets the emission standards, and is discharged into the atmosphere.

[0048] Furthermore, the organic gas recovery and purification device provided in this application embodiment also includes a concentration sensor 600 and an automatic regulating solenoid valve 700. The concentration sensor 600 is disposed between the circulating pump 500 and the liquid inlet 460, and the automatic regulating solenoid valve 700 is disposed on one of the branch pipes connected to the outlet of the circulating pump 500. When the concentration sensor 600 detects that the concentration of NMP in the first medium from the drain port 450 does not meet the recovery conditions, the automatic regulating solenoid valve 700 is closed, allowing the liquid from the drain port 450 to enter the tower body 410 through the liquid inlet 460 for continued circulation. When the concentration sensor 600 detects that the concentration of NMP in the liquid from the drain port 450 meets the recovery conditions, the automatic regulating solenoid valve 700 is opened to recover NMP.

[0049] It should be noted that the first absorption mechanism 430 and the second absorption mechanism 480 in this embodiment can be liquid dispersers, such as stainless steel wire mesh corrugated packing, stainless steel perforated corrugated packing, etc. There are no restrictions here, and users can choose according to their actual needs.

[0050] Further reference Figure 1As shown, in a preferred embodiment of this application, the condensing assembly 300 includes a cooling water coil 310 and a chilled water coil 320 arranged sequentially along the airflow direction. It should be understood that this embodiment is merely a preferred example, and those skilled in the art can select at least one of a cooling water coil, a chilled water coil, a heat pipe, or a direct expansion coil as the condensing assembly in this application according to actual needs. The cooling water coil and chilled water coil should not be considered as limitations on the scope of protection of the condensing assembly in this application.

[0051] It should be noted that, in this embodiment, the specific components included in the condenser assembly 300 are not limited. Users can select one or more of the cooling water coil 310 and chilled water coil 320 according to actual needs. Furthermore, this embodiment also does not limit the specific number of cooling water coils 310 and chilled water coils 320; users can set them according to actual needs.

[0052] Further reference Figure 1 As shown, in a preferred embodiment of this application, the air inlet 470 of the absorption distillation tower is connected to the return air circuit. Specifically, the air inlet 470 of the absorption distillation tower is connected to both the air outlet of the condensation assembly 300 and the second outlet 240 of the heat exchange assembly 200. It is understood that when the condensation assembly 300 consists of a cooling water coil 310 and a chilled water coil 320, the air outlet of the condensation assembly 300 specifically refers to the air outlet of the chilled water coil 320. The low-temperature gas treated by the condensation assembly 300 mixes with the high-temperature gas from the heat exchange assembly 200 and enters the absorption distillation tower through the air inlet 470.

[0053] The temperature of the mixed gas is preferably 60% to 80% of the boiling point temperature of the low-boiling liquid in the mixed liquid in the absorption distillation tower. Taking pure water as the absorbent as an example, as a preferred example, in the embodiments of this application, the temperature of the mixed gas entering the absorption distillation tower is any value between 60 and 80°C, such as 60°C, 65°C, 70°C, 75°C, 80°C, etc., which will not be listed exhaustively here. Preferably, the temperature of the mixed gas entering the absorption distillation tower is any value between 65 and 75°C.

[0054] Reference Figure 2 As shown, under the same operating conditions, if the evaporation rate of water at its boiling point under normal pressure is taken as 100%, we find that when the water temperature is below 55℃, its evaporation rate is less than 4%, and the critical range where the evaporation rate rapidly increases is when the water temperature reaches 60-80℃. Furthermore, referring to... Figure 3As shown, within this temperature range, the evaporation rate of NMP remains at a relatively low level, while when the temperature exceeds 120℃, the evaporation rate of NMP reaches a rapid inflection point. Therefore, on the one hand, if the temperature of the mixed gas entering the absorption and distillation tower is below 55℃, the evaporation rate of moisture is too low to meet the operating requirements of the distillation tower. On the other hand, considering the purification efficiency of the upper absorption tower, excessively high temperatures will reduce the absorption efficiency, and may even cause the exhaust gas emissions from the top of the tower to fail to meet emission standards. Considering the temperature requirements of both the absorption tower and the distillation tower, this application proposes an inlet air temperature range of 60-80℃ for the absorption and distillation tower.

[0055] To facilitate control of the flow rate and temperature of the gas entering the relevant components, a fan may also be installed at the relevant location in this embodiment. Further reference... Figure 1 As shown, when the inlet 470 of the absorption distillation tower is connected to the return air circuit, to facilitate the control of the flow rate and temperature of the mixed gas entering the absorption distillation tower, a first fan 810 and a second fan 820 can be respectively installed between the outlet of the condenser assembly 300 and the inlet 470 of the absorption distillation tower, and between the second outlet 240 of the heat exchange assembly 200 and the inlet 470 of the absorption distillation tower. Taking the condenser assembly 300 as being composed of a cooling water coil 310 and a chilled water coil 320 as an example, the inlet of the first fan 810 is connected to the outlet of the chilled water coil 320, the outlet of the first fan 810 is connected to both the second inlet 230 of the heat exchange assembly 200 and the inlet of the second fan 820, the inlet of the second fan 820 is connected to the outlet of the chilled water coil 320, and the outlet of the second fan 820 is connected to the inlet 470 of the absorption distillation tower.

[0056] To further control the mixed gas entering the absorption and distillation tower 400, as a preferred embodiment, a temperature sensor 900 can be installed on the mixed gas duct. By adjusting the flow rates of the first fan 810 and the second fan 820 in conjunction with the temperature sensor 900, the temperature of the mixed gas entering the absorption and distillation tower 400 can be automatically adjusted.

[0057] During operation, the high-temperature exhaust gas generated in the exhaust gas source 100 is discharged from the outlet of the exhaust gas source 100 and enters the heat exchange component 200 through the first inlet 210. There, it exchanges heat with the low-temperature exhaust gas flowing in through the second inlet 230 of the heat exchange component 200. The high-temperature exhaust gas, after heat exchange, is converted into low-temperature exhaust gas, which enters the air inlet of the condensing component 300 (in this embodiment, the air inlet of the cooling water coil 310) from the first outlet 220 of the heat exchange component 200. NMP is then condensed and recovered in the condensing component 200. The recovered low-temperature gas flows out from the air outlet of the condensing component 300 (in this embodiment, the air outlet of the chilled water coil 320). At this point, the gas still contains NMP. The NMP gas, after being partially condensed and recovered by the first fan 810, enters the second inlet 230 of the heat exchange component 200 and exchanges heat with the high-temperature exhaust gas from the first inlet 210 of the heat exchange component 200, thereby realizing the recycling of heat energy and achieving energy saving. The high-temperature gas flowing out of the second outlet 240 of the heat exchange component 200 and another part of the condensed and recovered low-temperature gas are mixed by the second fan 820 to form a mixed gas, which is sent to the inlet 470 of the absorption and distillation tower. After absorption and distillation treatment in the absorption and distillation tower 400, the NMP concentrate obtained by distillation that meets the recovery conditions is recovered at the outlet 450, and the purified gas is discharged into the atmosphere from the exhaust port 440 at the top of the tower.

[0058] As a preferred embodiment, the heat exchange assembly 200 in this application includes, but is not limited to, at least one of a corrugated plate gas-to-gas exchanger or a heat pipe heat exchanger. A corrugated plate gas-to-gas exchanger is preferred, and it is inclined at a 45° angle to the bottom surface of the shell. It should be understood that the type, quantity, and arrangement of heat exchangers in this application are merely preferred examples, and any other conventional heat exchangers in the prior art, such as shell-and-tube heat exchangers, double tube sheet heat exchangers, ceramic heat exchangers, and regenerative heat exchangers, should also be included within the scope of protection of this application.

[0059] In a preferred embodiment of this application, the apparatus may further include an intermediate storage tank 1000 for concentrated absorbent, which is connected to the drain port 450 of the absorption distillation tower, the heat exchange assembly 200, and the condensation assembly 300, so as to recover waste liquid containing NMP generated by the absorption distillation tower, the heat exchange assembly 200, and the condensation assembly 300.

[0060] Example 2

[0061] The difference from Embodiment 1 is that, referring to Figure 4As shown in the embodiment of this application, the air inlet 470 of the absorption distillation tower is connected to the air outlet circuit. Specifically, the air inlet 470 of the absorption distillation tower is connected to the air outlet of the waste gas source 100 and the first outlet 220 of the heat exchange component 200. The high-temperature gas from the waste gas source 100 and the low-temperature gas from the heat exchange component 200 are mixed and then enter the absorption distillation tower through the air inlet 470. Similarly, the temperature of the mixed gas is preferably 60% to 80% of the boiling point temperature of the low-boiling-point liquid in the mixed liquid within the absorption distillation tower. As a preferred example, in this embodiment of the application, the temperature of the mixed gas entering the absorption distillation tower is any value between 60 and 80°C, such as 60°C, 65°C, 70°C, 75°C, 80°C, etc., which will not be listed exhaustively here. Preferably, the temperature of the mixed gas entering the absorption distillation tower is any value between 65 and 75°C.

[0062] Further reference Figure 4 As mentioned above, when the air inlet 470 of the absorption distillation tower is connected to the air outlet circuit, in order to facilitate the control of the flow rate and temperature of the mixed gas entering the absorption distillation tower, on the one hand, a first fan 810' and a second fan 820' can be respectively installed between the air outlet of the condensing component 300 and the second inlet 230 of the heat exchange component 200, the air outlet of the waste gas source 100, and between the first outlet 220 of the heat exchange component 200 and the air inlet 470 of the absorption distillation tower. Taking the condenser assembly 300, which consists of a cooling water coil 310 and a chilled water coil 320, as an example, the air inlet of the first fan 810' is connected to the air outlet of the chilled water coil 320, the air outlet of the first fan 810' is connected to the second inlet 230 of the heat exchange assembly 200, the air inlet of the second fan 820' is connected to the air outlet of the waste gas source 100 and the first outlet 220 of the heat exchange assembly 200, and the air outlet of the second fan 820' is connected to the air inlet 470 of the absorption distillation tower.

[0063] Further reference Figure 4 In this embodiment of the application, the temperature sensor 900' is installed on the duct at the outlet of the exhaust gas source 100. By adjusting the flow rate of the second fan 820' in conjunction with the temperature sensor 900', the temperature of the mixed gas entering the absorption and distillation tower 400 is automatically adjusted.

[0064] In the description of this application, it should be understood that the terms "vertical," "parallel," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0065] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0066] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An organic gas recovery and purification device, characterized in that, The device includes a waste gas source, a heat exchange assembly, a condensation assembly, an absorption distillation tower, an exhaust circuit, and a return circuit. The air outlet circuit includes an air path from the outlet of the exhaust gas source through the heat exchange component to the inlet of the condensation component. The return air circuit includes an air path from the outlet of the condenser assembly through the heat exchange assembly to the inlet of the exhaust gas source. The outlet of the exhaust gas source is connected to the first inlet of the heat exchange component, the first outlet of the heat exchange component is connected to the inlet of the condensation component, the outlet of the condensation component is connected to the second inlet of the heat exchange component, the second outlet of the heat exchange component is connected to the inlet of the exhaust gas source, and the inlet of the absorption distillation tower is connected to the air outlet circuit or the air return circuit. The absorption and distillation tower includes a distillation section and an absorption section arranged sequentially along the gas flow direction. The absorption section and the distillation section are arranged vertically. The absorption section is configured to absorb waste gas in the mixed gas entering the tower, and the distillation section is configured to distill the waste gas. The gas inlet is located at the lower part of the distillation section, and the temperature of the gas entering the absorption and distillation tower at the gas inlet is 60-80℃.

2. The organic gas recovery and purification device according to claim 1, characterized in that, The distillation section includes a first spraying mechanism, a first absorption mechanism, and a first medium circulation path; The first medium circulation path includes a drain port, a circulation pump, and a liquid inlet. The inlet of the circulation pump is connected to the drain port, the outlet of the circulation pump is connected to the liquid inlet, and the liquid inlet is connected to the first spraying mechanism. The first absorption mechanism enables the gas to fully contact the first medium.

3. The organic gas recovery and purification device according to claim 2, characterized in that, The outlet of the circulating pump is provided with a branch pipeline, which is connected to the intermediate storage tank of the concentrated absorbent.

4. The organic gas recovery and purification device according to claim 2, characterized in that, The absorption section includes a second spraying mechanism, a second absorption mechanism, a second medium flow path, and an exhaust port; The second spraying mechanism is connected to the second medium flow path, and the second absorption mechanism ensures that the gas and the second medium are in full contact.

5. The organic gas recovery and purification device according to claim 4, characterized in that, After being sprayed, the flow direction of the first medium and / or the second medium in the absorption distillation tower forms an angle of 90-180° with the gas flow direction.

6. The organic gas recovery and purification device according to claim 3, characterized in that, The device further includes a concentration sensor for detecting the concentration of the first medium and an automatic regulating solenoid valve. The concentration sensor is disposed between the circulating pump and the inlet, and the automatic regulating solenoid valve is disposed on the branch pipeline.

7. The organic gas recovery and purification device according to any one of claims 1 to 6, characterized in that, The outlet of the condensing component and the second outlet of the heat exchange component are both connected to the inlet of the absorption distillation tower. The gas treated by the condensing component is mixed with the gas from the heat exchange component and then enters the absorption distillation tower.

8. The organic gas recovery and purification device according to any one of claims 1 to 6, characterized in that, The outlet of the waste gas source and the first outlet of the heat exchange component are both connected to the inlet of the absorption and distillation tower. The gas from the waste gas source and the gas from the heat exchange component are mixed and then enter the absorption and distillation tower.

9. The organic gas recovery and purification device according to any one of claims 1 to 6, characterized in that, The condensation assembly includes a cooling water coil and a chilled water coil. The air inlet of the cooling water coil is connected to the first outlet of the heat exchange assembly, the air outlet of the cooling water coil is connected to the air inlet of the chilled water coil, and the air outlet of the chilled water coil is connected to at least the second inlet of the heat exchange assembly.

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