Device and method for treating VOCs waste gas

Abstract

The invention discloses a VOCs waste gas treatment device and method, and relates to the technical field of VOCs treatment. The device comprises two adsorbers arranged side by side, waste gas distribution pipes are fixedly mounted at the bottoms of the adsorbers, a same waste gas three-way valve is fixedly mounted at one ends of the two waste gas distribution pipes, and a same discharge three-way pipe is fixedly mounted at the tops of the two adsorbers; first desorption gas-distributing pipes are fixedly mounted at the tops of the adsorbers, and the same first desorption three-way pipe is fixedly mounted at one ends of the two first desorption gas-distributing pipes. The two adsorbers are arranged, so that treated ultralow-concentration tail gas is discharged through the discharge three-way pipe, after the waste gas discharged by the discharge three-way pipe is purified, when the concentration of VOCs in the waste gas still reaches 20 mg / m < 3 >, the second adsorber is switched to perform adsorption, the first adsorber starts to perform desorption, alternate adsorption purification and desorption regeneration of the two adsorbers are achieved, and the adsorption efficiency is improved. And continuous ultra-low emission and water-free recovery of the VOCs are completed.

Description

Technical Field

[0001] This invention relates to the field of VOCs treatment technology, and specifically to a device and method for treating VOCs waste gas. Background Technology

[0002] Most volatile organic compounds (VOCs) are toxic and carcinogenic. To prevent direct emissions from harming human health and the environment, common VOCs treatment methods are divided into destructive treatment methods, such as high-temperature incineration and biodegradation, and recycling treatment methods, such as adsorption, absorption, and condensation. Although VOCs are harmful, they are also important industrial resources. Using recycling methods for treatment is more in line with the current needs of dual-carbon energy conservation and circular economy. In view of the high energy consumption and compliance issues in recycling methods, adsorption concentration + condensation recovery is a promising VOCs treatment method.

[0003] The currently used nitrogen desorption-condensation recovery technology often uses activated carbon for adsorption. Due to the properties of activated carbon itself, moisture is inevitably adsorbed during the adsorption process. Although the water content of the recovered solvent is lower than that of water vapor desorption, it is still impossible to completely remove moisture. At the same time, the adsorber desorption is incomplete, making it difficult to achieve ultra-low emissions. Therefore, a VOCs waste gas treatment device and method are proposed. Summary of the Invention

[0004] The purpose of this invention is to address the problem that current nitrogen desorption-condensation recovery technologies for VOCs cannot achieve ultra-low emissions and complete dehydration. This invention provides a device and method for treating VOCs waste gas.

[0005] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0006] A VOCs waste gas treatment device includes two adsorbers arranged side by side. Each adsorber has a waste gas distribution pipe fixedly installed at its bottom. One end of each waste gas distribution pipe is fixedly installed with the same waste gas three-way valve. The tops of both adsorbers are fixedly installed with the same discharge three-way pipe. Each adsorber has a first desorption distribution pipe fixedly installed at its top. One end of each of the two first desorption distribution pipes is fixedly installed with the same first desorption three-way valve. A second desorption distribution pipe connected to each waste gas distribution pipe is fixedly installed on one side of each waste gas distribution pipe. One end of each of the two second desorption distribution pipes is fixedly installed with the same second desorption three-way valve. The first desorption three-way valve and the second desorption three-way valve... One end of the three-way pipe is fixedly installed with a first desorption gas supply pipe and a second desorption gas supply pipe. A switching box and a recovery integration device are arranged sequentially on one side of the two adsorbers. One end of the first desorption gas supply pipe and the second desorption gas supply pipe both extend into the interior of the switching box. An inert gas pipe and a recovery pipe are fixedly installed on the side of the switching box away from the adsorber. One end of the recovery pipe extends into the interior of the recovery integration device. A first desorption control valve is provided on each of the first desorption gas distribution pipes. A second desorption control valve is provided on each of the second desorption gas distribution pipes. A recovery control valve is provided on the recovery pipe. An emission control valve is provided at the end of the emission three-way pipe located inside the waste gas distribution pipe.

[0007] Furthermore, each of the adsorbers is equipped with a spiral gas film tube inside, and the two ends of the spiral gas film tube are respectively connected to the waste gas distribution pipe and the first desorption gas distribution pipe.

[0008] Furthermore, the switching box is equipped with a circulating desorption mechanism connected to the first desorption gas supply pipe and the second desorption gas supply pipe. The circulating desorption mechanism is used to switch the nitrogen supply pipeline and the VOCs recovery pipeline. The circulating desorption mechanism includes two switching pipes disposed inside the switching box. The positions of the two switching pipes correspond to the positions of the first desorption gas supply pipe and the second desorption gas supply pipe, respectively. A metal bellows is fixedly installed at the end of each switching pipe away from the first desorption gas supply pipe and the second desorption gas supply pipe. One end of each metal bellows is fixedly connected to the end of the inert gas pipe and the recovery pipe located inside the switching box, respectively. The same switching gear is fixedly sleeved on the two switching pipes. A C-shaped slide rail is fixedly installed inside the switching box. The switching gear is slidably installed on the C-shaped slide rail. A switching motor is fixedly installed inside the switching box. A switching gear that meshes with the switching gear is fixedly sleeved on the output shaft of the switching motor.

[0009] Furthermore, both ends of the spiral gas film tube are screwed with pressurizing spiral buckets, and one end of each of the two pressurizing spiral buckets is fixedly connected to the first desorption gas separator and the end of the waste gas separator located inside the adsorber, respectively. The interior of the pressurizing spiral bucket is provided with multiple evenly distributed spiral grooves.

[0010] Furthermore, each of the spiral air film tubes contains a scraping ball that is compatible with the spiral air film tube.

[0011] Furthermore, the first desorption gas supply pipe, the second desorption gas supply pipe, and the two switching pipes are all fixedly fitted with sealing rings at their respective ends, with the four sealing rings fitting together in pairs.

[0012] Furthermore, the internal components of the integrated recycling equipment are sequentially arranged as a heater, a gas heat exchanger, a dehydrator, a VOCs condenser, and a desorption fan. The heater, the gas heat exchanger, the dehydrator, the VOCs condenser, the desorption fan, and the recycling control valve are connected to the circulation pipeline through a control valve group.

[0013] A method for treating VOCs waste gas includes the following steps:

[0014] S1. Waste gas adsorption: Waste gas enters the interior of one of the adsorbers through the waste gas three-way valve for adsorption. The VOCs contained in the waste gas are retained on the inner wall of the spiral gas membrane tube. The filtered tail gas passes through the spiral gas membrane tube and is discharged through the exhaust three-way pipe.

[0015] S2, Adsorption Switching: When the concentration of VOCs inside the emission tee still reaches 20 mg / m³ 3 At this time, the three-way valve for exhaust gas is switched to allow the second adsorber to engage in adsorption and purification.

[0016] S3, Desorption and Regeneration: The first desorption control valve and the second desorption control valve on the side of the first adsorber are connected, the discharge control valve is closed, and the first desorption tee and the second desorption tee are switched to the pipeline where the first adsorber is located, so that the first adsorber can start desorption and regeneration.

[0017] S4. Bidirectional desorption: After a certain period of unidirectional desorption, the position of the two switching tubes driven by the switching motor is exchanged, so that the inlet pipe and outlet pipe of the inert gas are switched, and the inert gas flows in reverse inside the spiral gas film tube to achieve bidirectional desorption.

[0018] S5. Concentration and Recovery: The desorbed high-concentration VOCs enter the integrated recovery equipment, are pre-cooled by the heat recovery of the gas heat exchanger, then enter the dehydrator to remove moisture, and then enter the VOCs condenser for liquefaction and recovery. They are then sent back to the gas heat exchanger to recover cold energy for preheating, and finally sent to the heater by the desorption fan for circulation until concentrated VOCs are obtained.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. This invention uses two adsorbers to ensure that the treated ultra-low concentration exhaust gas is discharged through a three-way exhaust pipe. Even after purification, the VOCs concentration in the exhaust gas discharged through the three-way exhaust pipe still reaches 20 mg / m³. 3 When the first adsorber starts to desorb, the second adsorber is switched to the second adsorber for adsorption, and the first adsorber starts to desorb, realizing the alternating adsorption purification and desorption regeneration of the two adsorbers, and completing the uninterrupted ultra-low emission and waterless recovery of VOCs.

[0021] 2. This invention, by setting up a spiral air film tube, allows exhaust gas to enter the spiral air film tube, where the VOCs contained inside are retained on the inner wall of the spiral air film tube. The filtered exhaust gas passes through the spiral air film tube and is discharged through the emission control valve and the emission tee. The spiral structure with ultra-small gaps of the spiral air film tube greatly increases the area where VOCs are filtered and retained, and increases the amount of VOCs retained, thereby achieving ultra-low concentration exhaust gas emissions.

[0022] 3. This invention sets up a circulating desorption mechanism so that inert gas enters the spiral gas film tube for desorption, and then enters the recovery integration equipment for concentration, condensation and dehydration recovery. After a certain period of unidirectional desorption, the position of the two switching tubes is exchanged by the switching motor, so that the inert gas flows in the opposite direction inside the spiral gas film tube, realizing bidirectional desorption, increasing the desorption amount, and making the desorption of the spiral gas film tube more thorough.

[0023] 4. This invention, by setting up an integrated recovery device, allows high-concentration VOCs desorbed by inert gas to enter the integrated recovery device through a recovery pipe and a recovery control valve. They are pre-cooled by heat recovery in a gas heat exchanger, then enter a dehydrator to further remove moisture from the VOCs, and then enter a VOCs condenser for liquefaction and recovery, reducing the concentration. After that, they are sent back to the gas heat exchanger for heat recovery and preheating, and finally sent to a heater by a desorption fan, thus circulating until concentrated VOCs are obtained, achieving waterless recovery of VOCs. Attached Figure Description

[0024] Figure 1 This is a first-view three-dimensional structural diagram of the present invention;

[0025] Figure 2 This is a schematic diagram of the second-view three-dimensional structure of the present invention;

[0026] Figure 3 This is a schematic diagram of the three-dimensional structure of the adsorber of the present invention;

[0027] Figure 4 This is a schematic diagram of the three-dimensional structure of the spiral air film tube and the pressurizing spiral bucket of the present invention;

[0028] Figure 5 This is a schematic diagram of the three-dimensional structure of the pressurized spiral bucket of the present invention;

[0029] Figure 6 This is a schematic diagram of the internal three-dimensional structure of the spiral air film tube of the present invention;

[0030] Figure 7 This is a schematic diagram of the three-dimensional structure of the scraping ball of the present invention;

[0031] Figure 8 This is a schematic diagram of the internal three-dimensional structure of the switching box of the present invention;

[0032] Figure 9 This is a three-dimensional structural diagram of the switching tube of the present invention in conjunction with the first desorption gas delivery tube and the second desorption gas delivery tube;

[0033] Figure 10 This is a schematic diagram of a VOCs waste gas treatment method according to the present invention;

[0034] Reference numerals: 1. Adsorber; 2. Exhaust gas distribution pipe; 3. Exhaust gas three-way valve; 4. Discharge three-way pipe; 5. First desorption distribution pipe; 6. First desorption three-way pipe; 7. First desorption gas supply pipe; 8. Switching box; 9. Inert gas pipe; 10. Second desorption distribution pipe; 11. Second desorption three-way pipe; 12. Second desorption gas supply pipe; 13. Recovery pipe; 14. Recovery integrated equipment; 15. First desorption control valve; 16. Second desorption control valve; 17. Recovery control valve; 18. Spiral gas film pipe; 19. Pressurized spiral bucket; 1901. Spiral groove; 20. Scraping ball; 21. Switching pipe; 22. Switching gear plate; 23. C-shaped slide rail; 24. Metal bellows; 25. Switching motor; 26. Switching gear; 27. Sealing ring; 28. Discharge control valve. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] In the description of the embodiments of the present invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention 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. Therefore, they should not be construed as limiting the present invention.

[0039] like Figures 1 to 9 As shown, a VOCs waste gas treatment device includes two adsorbers 1 arranged side by side, such as... Figure 1 , Figure 2 As shown, specifically, each of the two adsorbers 1 has a waste gas distribution pipe 2 fixedly installed at its bottom. One end of each waste gas distribution pipe 2 is fixedly installed with the same waste gas three-way valve 3. The tops of both adsorbers 1 have the same discharge three-way pipe 4 fixedly installed. Each adsorber 1 has a first desorption distribution pipe 5 fixedly installed at its top. One end of each of the two first desorption distribution pipes 5 is fixedly installed with the same first desorption three-way pipe 6. Each of the waste gas distribution pipes 2 has a second desorption distribution pipe 10 fixedly installed on one side, communicating with the waste gas distribution pipe 2. One end of each of the two second desorption distribution pipes 10 is fixedly installed with the same second desorption three-way pipe 11. Figure 9 As shown, a first desorption gas supply pipe 7 and a second desorption gas supply pipe 12 are fixedly installed at one end of the first desorption tee pipe 6 and the second desorption tee pipe 11, respectively. A switching box 8 and a recovery integration device 14 are sequentially arranged on one side of the two adsors 1. One end of the first desorption gas supply pipe 7 and the second desorption gas supply pipe 12 both extend into the interior of the switching box 8, as shown. Figure 8 As shown, an inert gas pipe 9 and a recovery pipe 13 are fixedly installed on the side of the switching box 8 away from the adsorber 1. One end of the recovery pipe 13 extends into the interior of the recovery integration device 14. A first desorption control valve 15 is installed on each of the first desorption gas distribution pipes 5, a second desorption control valve 16 is installed on each of the second desorption gas distribution pipes 10, and a recovery control valve 17 is installed on the recovery pipe 13. Figure 3 As shown, an exhaust control valve 28 is installed at one end of the exhaust tee 4 located inside the exhaust gas distribution pipe 2.

[0040] In this embodiment, one end of the exhaust gas three-way valve 3 can be connected to a dry filter and a pre-cooling surface cooler. The dry filter and the pre-cooling surface cooler are connected to the air inlet. The dry filter is used to initially remove particulate matter from the exhaust gas, and the pre-cooling surface cooler is used to cool the exhaust gas. One end of the inert gas pipe 9 is connected to an inert gas output source, and the inert gas output source is connected to the pipeline inside the recycling integration device 14.

[0041] More specifically, in the VOCs waste gas treatment device, the waste gas passes through a dry filter and a pre-cooling surface cooler sequentially through the inlet. After the particulate matter concentration and temperature of the waste gas meet the adsorption requirements, it enters one of the adsorbers 1 through the three-way valve 3 for adsorption. The ultra-low concentration tail gas after adsorption treatment is discharged through the three-way exhaust pipe 4. The filtered organic matter in the waste gas is adsorbed and retained inside the adsorber 1. Even after purification, the concentration of VOCs in the waste gas discharged through the three-way exhaust pipe 4 still reaches 20 mg / m³. 3 When this occurs, it indicates that desorption is needed inside the current adsorber 1. At this time, the exhaust gas three-way valve 3 is switched, allowing the second adsorber 1 to engage in adsorption and purification. Meanwhile, the first desorption control valve 15 and the second desorption control valve 16 on the side of the first adsorber 1 are connected, the emission control valve 28 is closed, and the first desorption three-way pipe 6 and the second desorption three-way pipe 11 are switched to the pipeline where the first adsorber 1 is located, causing the first adsorber 1 to begin desorption and regeneration. At this time, inert gas is introduced into the inert gas pipe 9, passing through the switching box 8 and the first... A desorption gas supply pipe 7, a first desorption tee pipe 6, and a first desorption gas distribution pipe 5 are introduced into the interior of the adsorber 1 to desorb VOCs. The VOCs mixed with nitrogen gas are then transported through the second desorption control valve 16, the second desorption gas distribution pipe 10, the second desorption tee pipe 11, the second desorption gas supply pipe 12, the switching box 8, and the recovery pipe 13 to the integrated recovery equipment 14 for concentration, dehydration, and recovery. This achieves alternating adsorption purification and desorption regeneration of the two adsorbers 1, completing uninterrupted ultra-low emissions and waterless recovery of VOCs.

[0042] like Figure 3 , Figure 4 As shown, specifically, each of the adsorber 1 is equipped with a spiral gas film tube 18, and the two ends of the spiral gas film tube 18 are connected to the waste gas distribution tube 2 and the first desorption distribution tube 5, respectively.

[0043] More specifically, by setting up a spiral gas membrane tube 18, the exhaust gas enters the spiral gas membrane tube 18, and the VOCs contained inside are retained on the inner wall of the spiral gas membrane tube 18. The filtered exhaust gas passes through the spiral gas membrane tube 18 and is discharged through the emission control valve 28 and the emission tee 4. The spiral structure with ultra-small gaps of the spiral gas membrane tube 18 greatly increases the area where VOCs are filtered and retained, and increases the amount of VOCs retained, thereby achieving ultra-low concentration exhaust gas emissions. When inert gas is introduced into the spiral gas membrane tube 18, the inert gas contacts the inner wall of the spiral gas membrane tube 18 and carries out the VOCs. Then, the mixed VOCs are discharged through the exhaust gas separator 2 for desorption.

[0044] The switching box 8 is internally equipped with a circulating desorption mechanism connected to the first desorption gas supply pipe 7 and the second desorption gas supply pipe 12. This circulating desorption mechanism is used to switch between the nitrogen supply pipeline and the VOCs recovery pipeline 13. Figure 8 , Figure 9 As shown, specifically, the circulating desorption mechanism includes two switching pipes 21 disposed inside the switching box 8. The positions of the two switching pipes 21 correspond to the positions of the first desorption gas supply pipe 7 and the second desorption gas supply pipe 12, respectively. A metal bellows 24 is fixedly installed on the end of the switching pipe 21 away from the first desorption gas supply pipe 7 and the second desorption gas supply pipe 12. One end of the two metal bellows 24 is fixedly connected to the end of the inert gas pipe 9 and the recovery pipe 13 located inside the switching box 8, respectively. The same switching gear 22 is fixedly sleeved on the two switching pipes 21. A C-shaped slide rail 23 is fixedly installed inside the switching box 8. The switching gear 22 is slidably installed on the C-shaped slide rail 23. A switching motor 25 is fixedly installed inside the switching box 8. A switching gear 26 that meshes with the switching gear 22 is fixedly sleeved on the output shaft of the switching motor 25.

[0045] More specifically, by setting up a circulating desorption mechanism, the inert gas sequentially passes through the inert gas pipe 9, the first metal bellows pipe 24, the first switching pipe 21, the first desorption gas supply pipe 7, the first desorption tee pipe 6, and the first desorption gas distribution pipe 5 into the spiral gas film pipe 18 for desorption. Then, it passes through the waste gas distribution pipe 2, the second desorption control valve 16, the second desorption gas distribution pipe 10, the second desorption tee pipe 11, the second desorption gas supply pipe 12, the second switching pipe 21, the second metal bellows pipe 24, and the recovery pipe 13 into the return pipe. The collection device 14 performs concentration, condensation, and dehydration recovery. Simultaneously, after a certain period of unidirectional desorption, the switching motor 25 drives the switching gear 26 to rotate the switching toothed disc 22, which in turn drives the two switching tubes 21 to rotate alternately. The two metal bellows 24 intertwine with each other, causing the positions of the two switching tubes 21 to be exchanged. This switches the inert gas inlet and outlet pipelines, allowing the inert gas to flow in reverse into the spiral gas film tube 18, achieving bidirectional desorption, increasing the desorption amount, and making the desorption of the spiral gas film tube 18 more thorough.

[0046] like Figure 4 , Figure 5 As shown, specifically, both ends of the spiral gas film tube 18 are screwed to the pressurizing spiral buckets 19. One end of each of the two pressurizing spiral buckets 19 is fixedly connected to the first desorption gas separator 5 and the exhaust gas separator 2 located inside the adsorber 1. The interior of the pressurizing spiral buckets 19 is provided with multiple evenly distributed spiral grooves 1901.

[0047] More specifically, by setting up a pressurizing spiral bucket 19, the pressurizing spiral bucket 19 can increase the inlet speed and pressure of the inert gas by means of its gradually narrowing diameter and the spiral grooves 1901 set on the inner wall, thereby increasing the desorption capacity of the inert gas for VOCs.

[0048] like Figure 6 , Figure 7 As shown, specifically, each spiral air film tube 18 contains a scraping ball 20 that is compatible with the spiral air film tube 18.

[0049] In this embodiment, the outer diameter of the scraping ball 20 is slightly smaller than the inner diameter of the spiral film tube 18.

[0050] More specifically, by setting up scraping balls 20, the tiny particles that are not completely removed by the dry filter will adhere to the inner wall of the spiral air film tube 18. The scraping balls 20 are subjected to the action of inert gas pressurized by the pressurized spiral bucket 19, and roll back and forth inside the spiral air film tube 18, thereby scraping the inner wall of the spiral air film tube 18, and scraping off the tiny particles, which are then desorbed and discharged with the VOCs surging out of the inert gas.

[0051] like Figure 9 As shown, specifically, the first desorption gas supply pipe 7, the second desorption gas supply pipe 12 and the two switching pipes 21 are all fixedly fitted with sealing rings 27 at their ends, and the four sealing rings 27 are in pairs.

[0052] More specifically, by setting a sealing ring 27, the two switching pipes 21 can be fitted with the ports of the first desorption gas pipe 7 and the second desorption gas pipe 12 through the sealing ring 27 before and after rotation switching, thereby ensuring the sealing performance during gas transmission.

[0053] like Figure 2 As shown, specifically, the internal components of the recycling integrated equipment 14 are arranged in sequence as follows: a heater, a gas heat exchanger, a dehydrator, a VOCs condenser, and a desorption fan. The heater, gas heat exchanger, dehydrator, VOCs condenser, desorption fan, and recycling control valve 17 are connected to the circulation pipeline through a control valve group.

[0054] More specifically, by setting up a recycling integrated device 14, high-concentration VOCs desorbed by inert gas enter the recycling integrated device 14 through the recycling pipe 13 and the recycling control valve 17. They are pre-cooled by the heat recovered by the gas heat exchanger, and then enter the dehydrator to further remove the moisture from the VOCs. They then enter the VOCs condenser for liquefaction and recovery, and the concentration is reduced. After that, they are sent back to the gas heat exchanger to recover the cold energy for preheating. Finally, they are sent to the heater by the desorption fan to circulate until concentrated VOCs are obtained, thus achieving waterless recovery of VOCs.

[0055] like Figure 10 As shown, a method for treating VOCs waste gas includes the following steps:

[0056] S1. Waste gas adsorption: Waste gas enters the interior of one of the adsorbers 1 through the waste gas three-way valve 3 for adsorption. The VOCs contained in the waste gas are retained on the inner wall of the spiral gas membrane tube 18. The filtered tail gas passes through the spiral gas membrane tube 18 and is discharged through the exhaust three-way pipe 4.

[0057] S2, Adsorption Switching: When the concentration of VOCs inside the emission tee 4 still reaches 20 mg / m³ 3 At this time, the three-way valve 3 for exhaust gas is switched to allow the second adsorber 1 to engage in adsorption and purification.

[0058] S3, Desorption and Regeneration: The first desorption control valve 15 and the second desorption control valve 16 on one side of the first adsorber 1 are connected, the discharge control valve 28 is closed, and the first desorption tee pipe 6 and the second desorption tee pipe 11 are switched to the pipeline where the first adsorber 1 is located, so that the first adsorber 1 begins desorption and regeneration.

[0059] S4. Bidirectional desorption: After a certain period of unidirectional desorption, the switching motor 25 drives the two switching tubes 21 to exchange positions, thereby switching the inert gas inlet pipe and outlet pipe, and causing the inert gas to flow in reverse inside the spiral gas film tube 18 to achieve bidirectional desorption.

[0060] S5. Concentration and Recovery: The desorbed high-concentration VOCs enter the recovery integrated equipment 14, are pre-cooled by the heat recovery of the gas heat exchanger, then enter the dehydrator to remove moisture, and then enter the VOCs condenser for liquefaction and recovery. They are then sent back to the gas heat exchanger to recover cold energy for preheating, and finally sent to the heater by the desorption fan for circulation until concentrated VOCs are obtained.

[0061] In summary: Waste gas adsorption: Waste gas passes sequentially through a dry filter and a pre-cooling surface cooler via the inlet. After the particulate matter concentration and temperature of the waste gas meet the adsorption requirements, it enters one of the adsorbers 1 via the waste gas three-way valve 3 for adsorption. The waste gas then enters the spiral membrane tube 18, where the VOCs contained within are retained on the inner wall of the spiral membrane tube 18. The filtered exhaust gas passes through the spiral membrane tube 18 and is discharged via the emission control valve 28 and the emission three-way pipe 4. When the VOCs concentration inside the emission three-way pipe 4 still reaches 20 mg / m³... 3 When the time is right, it indicates that desorption needs to be performed inside the current adsorber 1. At this time, the exhaust gas three-way valve 3 is switched so that the second adsorber 1 can start adsorption and purification. Meanwhile, the first desorption control valve 15 and the second desorption control valve 16 on the side of the first adsorber 1 are connected, the emission control valve 28 is closed, and the first desorption three-way pipe 6 and the second desorption three-way pipe 11 are switched to the pipeline where the first adsorber 1 is located, so that the first adsorber 1 can start desorption and regeneration. At this time, inert gas is introduced into the inert gas pipe 9 and enters the adsorber 1 through the switching box 8 and the first desorption gas supply pipe 7, the first desorption three-way pipe 6, and the first desorption gas distribution pipe 5 to desorb VOCs. The VOCs mixed with nitrogen is transported to the recovery integration equipment 14 through the second desorption control valve 16 and the second desorption gas distribution pipe 10, the second desorption three-way pipe 11, the second desorption gas supply pipe 12, the switching box 8, and the recovery pipe 13 for concentration, dehydration and recovery, so as to realize the alternating adsorption purification and desorption regeneration of the two adsorbers 1.

[0062] Desorption and regeneration: Inert gas sequentially enters the spiral gas film tube 18 through the inert gas tube 9, the first metal bellows tube 24, the first switching tube 21, the first desorption gas supply tube 7, the first desorption tee tube 6, and the first desorption gas distribution tube 5 for desorption. Then, it enters the recovery integration equipment 14 through the waste gas distribution tube 2, the second desorption control valve 16, the second desorption gas distribution tube 10, the second desorption tee tube 11, the second desorption gas supply tube 12, the second switching tube 21, the second metal bellows tube 24, and the recovery tube 13 for concentration, condensation, and dehydration recovery. At the same time, after a certain period of unidirectional desorption, the switching motor 25 drives the switching gear 26 to rotate the switching gear disk 22, which in turn drives the two switching tubes 21 to rotate alternately. The two metal bellows tubes 24 are intertwined, so that the positions of the two switching tubes 21 are exchanged, thereby switching the inert gas inlet and outlet pipelines, and allowing the inert gas to flow in reverse inside the spiral gas film tube 18 to achieve bidirectional desorption.

[0063] Concentration and recovery: High-concentration VOCs desorbed by inert gas enter the integrated recovery equipment 14 through recovery pipe 13 and recovery control valve 17. They are pre-cooled by heat recovery in the gas heat exchanger, and then enter the dehydrator to further remove moisture from the VOCs. They then enter the VOCs condenser for liquefaction and recovery, and the concentration is reduced. After that, they are sent back to the gas heat exchanger to recover cold energy for preheating. Finally, they are sent to the heater by the desorption fan to circulate until concentrated VOCs are obtained, thus achieving waterless recovery of VOCs.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A VOCs waste gas treatment device, characterized in that, The device includes two adsorbers (1) arranged side by side. Each adsorber (1) has a waste gas distribution pipe (2) fixedly installed at its bottom. One end of each waste gas distribution pipe (2) is fixedly fitted with the same waste gas three-way valve (3). The tops of both adsorbers (1) are fixedly fitted with the same discharge three-way pipe (4). Each adsorber (1) has a first desorption distribution pipe (5) fixedly installed at its top. One end of each of the two first desorption distribution pipes (5) is fixedly fitted with the same first desorption three-way pipe (6). One side of each waste gas distribution pipe (2) is fixedly fitted with a second desorption distribution pipe (10) connected to the waste gas distribution pipe (2). One end of each of the two second desorption distribution pipes (10) is fixedly fitted with the same second desorption three-way pipe (11). The first desorption three-way pipe (6) and the second desorption three-way pipe (11) are connected together. 1) One end is fixedly installed with a first desorption gas supply pipe (7) and a second desorption gas supply pipe (12). A switching box (8) and a recovery integration device (14) are arranged sequentially on one side of the two adsorbers (1). One end of the first desorption gas supply pipe (7) and the second desorption gas supply pipe (12) both extend into the interior of the switching box (8). An inert gas pipe (9) and a recovery pipe (13) are fixedly installed on the side of the switching box (8) away from the adsorber (1). One end of the recovery pipe (13) extends into the interior of the recovery integration device (14). The interior of the switching box (8) is provided with a circulating desorption mechanism that is connected to the first desorption gas supply pipe (7) and the second desorption gas supply pipe (12). The circulating desorption mechanism is used to switch the nitrogen delivery pipeline and the VOCs recovery pipeline (13).

2. The VOCs waste gas treatment device according to claim 1, characterized in that, The adsorber (1) is equipped with a spiral gas film tube (18) inside. The two ends of the spiral gas film tube (18) are connected to the waste gas distribution pipe (2) and the first desorption distribution pipe (5) respectively. The first desorption distribution pipe (5) is equipped with a first desorption control valve (15). The second desorption distribution pipe (10) is equipped with a second desorption control valve (16). The recovery pipe (13) is equipped with a recovery control valve (17). The end of the discharge tee pipe (4) located inside the waste gas distribution pipe (2) is equipped with a discharge control valve (28).

3. The VOCs waste gas treatment device according to claim 2, characterized in that, Both ends of the spiral gas film tube (18) are screwed with pressurizing spiral buckets (19). One end of each of the two pressurizing spiral buckets (19) is fixedly connected to the first desorption gas separator (5) and the exhaust gas separator (2) located inside the adsorber (1). The interior of the pressurizing spiral bucket (19) is provided with a plurality of evenly distributed spiral grooves (1901).

4. The VOCs waste gas treatment device according to claim 2, characterized in that, Each of the spiral air film tubes (18) contains a scraping ball (20) that is compatible with the spiral air film tube (18).

5. The VOCs waste gas treatment device according to claim 1, characterized in that, The circulating desorption mechanism includes two switching pipes (21) disposed inside the switching box (8). The positions of the two switching pipes (21) correspond to the positions of the first desorption gas supply pipe (7) and the second desorption gas supply pipe (12), respectively. A metal corrugated pipe (24) is fixedly installed at the end of the switching pipe (21) away from the first desorption gas supply pipe (7) and the second desorption gas supply pipe (12). One end of the two metal corrugated pipes (24) is connected to the inert gas pipe (9) and the recovery... One end of the tube (13) is fixedly connected inside the switching box (8). The same switching gear (22) is fixedly sleeved on the two switching tubes (21). A C-shaped slide rail (23) is fixedly installed inside the switching box (8). The switching gear (22) is slidably installed on the C-shaped slide rail (23). A switching motor (25) is fixedly installed inside the switching box (8). The output shaft of the switching motor (25) is fixedly sleeved with a switching gear (26) that meshes with the switching gear (22).

6. The VOCs waste gas treatment device according to claim 5, characterized in that, The first desorption gas supply pipe (7), the second desorption gas supply pipe (12), and the two switching pipes (21) are all fixedly fitted with sealing rings (27) at their ends, and the four sealing rings (27) are in pairs.

7. The VOCs waste gas treatment device according to claim 1, characterized in that, The integrated recycling equipment (14) is equipped with a heater, a gas heat exchanger, a dehydrator, a VOCs condenser, and a desorption fan in sequence. The heater, the gas heat exchanger, the dehydrator, the VOCs condenser, the desorption fan, and the recycling control valve (17) are connected to the circulation pipeline through a control valve group.

8. A method for treating VOCs waste gas using the treatment apparatus according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Waste gas adsorption: Waste gas enters the interior of one of the adsorbers (1) through the waste gas three-way valve (3) for adsorption. The VOCs contained in the waste gas are retained on the inner wall of the spiral gas membrane tube (18). The filtered tail gas passes through the spiral gas membrane tube (18) and is discharged through the discharge three-way pipe (4). S2, Adsorption Switching: When the concentration of VOCs inside the emission tee (4) still reaches 20 mg / m³ 3 At this time, the three-way valve (3) is switched to allow the second adsorber (1) to be put into adsorption and purification. S3, Desorption and Regeneration: The first desorption control valve (15) and the second desorption control valve (16) on one side of the first adsorber (1) are connected, the discharge control valve (28) is closed, and the first desorption tee (6) and the second desorption tee (11) are switched to the pipeline where the first adsorber (1) is located, so that the first adsorber (1) can start desorption and regeneration. S4. Bidirectional desorption: After a certain period of unidirectional desorption, the switching motor (25) drives the two switching tubes (21) to exchange positions, so that the inert gas inlet pipe and outlet pipe are switched, so that the inert gas flows in reverse inside the spiral gas film tube (18) to achieve bidirectional desorption. S5. Concentration and recovery: The high-concentration VOCs desorbed enter the integrated recovery equipment (14), are pre-cooled by the heat recovery of the gas heat exchanger, then enter the dehydrator to remove moisture, and then enter the VOCs condenser for liquefaction and recovery. They are then sent to the gas heat exchanger again to recover the cold energy for preheating, and finally sent to the heater by the desorption fan for circulation until concentrated VOCs are obtained.

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