Waste gas treatment device

Abstract

The embodiment of the utility model provides a waste gas treatment device, relates to the technical field of chinlon polymerization, and can be used for treating caprolactam-containing steam discharged by a strip casting system and a pelletizing system. The waste gas treatment device comprises a venturi ejector, and the input end of the venturi ejector is connected with the strip casting system and the pelletizing system. The gas-liquid separation tank is connected with the output end of the Venturi ejector; one output end of the gas-liquid separation tank is connected with the exhaust channel; the water tank is connected with the other output end of the gas-liquid separation tank; the input end of the delivery pump is connected with the water tank, and the output end of the delivery pump is connected with the input end of the Venturi ejector through a first valve; the second valve is arranged in the first pipeline, the first pipeline is used for being connected with a heating medium supply device, the first pipeline is further connected with the input end of the Venturi ejector, and the second valve is used for controlling the flow of a heating medium in the first pipeline.

Description

Technical Field

[0001] This disclosure relates to the field of nylon polymerization technology, and more particularly to a waste gas treatment device. Background Technology

[0002] Nylon 6, also known as polyamide 6, is a polymer compound. Nylon 6 possesses high strength, abrasion resistance, softness, and a gentle feel against the skin, making it widely used in clothing, silk, umbrellas, fishing net yarn, curtain yarn, carpet yarn, and engineering plastics.

[0003] In industrial production, caprolactam is used as the main raw material to produce nylon 6. In the polymerization tower, caprolactam undergoes a series of reactions, including hydrolysis and ring-opening, followed by polycondensation, to generate a polymer melt. After being pumped and filtered by a melt pump and melt filter, the polymer melt is extruded from a casting strip to form strips. These strips then enter a pelletizing system where they are cooled and solidified underwater. During this process, when the high-temperature strips come into contact with the low-temperature cooling water, a large amount of water vapor containing caprolactam is instantly generated. Utility Model Content

[0004] This disclosure provides an exhaust gas treatment device capable of treating caprolactam-containing vapors discharged from a casting strip system and a pelletizing system.

[0005] This disclosure provides an exhaust gas treatment device for nylon polymerization. The exhaust gas treatment device includes: a Venturi ejector, the input end of which is connected to a casting strip system and a pelletizing system respectively; a gas-liquid separator, the output end of which is connected to the Venturi ejector; one output end of the gas-liquid separator is connected to an exhaust channel; and a water tank, the other output end of which is connected to the gas-liquid separator. Under the negative pressure of the Venturi ejector, exhaust gas discharged from at least one of the casting strip system and the pelletizing system can enter the Venturi ejector. The gas-liquid mixture ejected by the Venturi ejector enters the gas-liquid separator for separation. The separated gas is discharged from the exhaust channel, and the separated liquid enters the water tank. A delivery pump, the input end of which is connected to the water tank, and the output end of which is connected to the input end of the Venturi injector via a first valve; when the first valve is switched to the open state, water in the water tank can be delivered to the Venturi injector under the suction action of the delivery pump; a second valve and a first pipeline, the second valve being disposed in the first pipeline, the first pipeline being used to connect to a heat medium supply device, the first pipeline also being connected to the input end of the Venturi injector, the second valve being used to control the flow rate of the heat medium in the first pipeline; when the second valve is switched to the open state, under the negative pressure action of the Venturi injector, the heat medium supplied by the heat medium supply device enters the Venturi injector through the first pipeline.

[0006] In one embodiment, the waste gas treatment device further includes: a second pipeline connected to the cast strip plate system, the second pipeline also connected to the first pipeline, and the connection point between the second pipeline and the first pipeline is located at the output end of the second valve; and a third valve for controlling the connection or disconnection between the cast strip plate system and the input end of the Venturi injector.

[0007] In one embodiment, the waste gas treatment device further includes: a third pipeline connected to the pelletizing system and also connected to the first pipeline, wherein the connection point between the third pipeline and the first pipeline is located at the output end of the second valve; and a fourth valve used to control the connection or disconnection between the pelletizing system and the input end of the Venturi injector.

[0008] In one embodiment, the second valve is connected in series with the third valve; the third valve is connected in parallel with the fourth valve.

[0009] In one embodiment, the waste gas treatment device further includes: a fourth pipeline connected between the output end of the delivery pump and the input end of the Venturi injector; and the first valve is disposed in the fourth pipeline.

[0010] In one embodiment, the waste gas treatment device further includes a fifth pipeline, which is connected between the fourth pipeline and the extraction system, and the connection between the fifth pipeline and the fourth pipeline is located at the input end of the first valve.

[0011] In one embodiment, the Venturi injector has a first input end and a second input end, the first pipeline is connected to the first input end, and the fourth pipeline is connected to the second input end; the exhaust gas treatment device further includes: a pressure gauge and a controller, the pressure gauge is disposed at the second input end, and the pressure gauge, the delivery pump, and the first valve are electrically connected to the controller.

[0012] In one embodiment, the water tank is provided with a partition for dividing the space inside the water tank into a first chamber and a second chamber. The first chamber is used to store cooling water or transport water, and the second chamber is connected to the output end of the gas-liquid separator and also to the input end of the transport pump.

[0013] In one embodiment, a flexible filter screen is provided at the end of the water tank, and the flexible filter screen is located at the top of the water tank. The flexible filter screen is used to filter the water entering the water tank. The exhaust gas treatment device further includes: a first roller, a drive motor, and a transmission belt. The first roller is used to wind the flexible filter screen. The drive motor is electrically connected to the controller in the exhaust gas treatment device. The drive motor drives the flexible filter screen to move toward the first roller through the transmission belt, so that the first roller winds the flexible filter screen, thereby updating the portion of the flexible filter screen located at the top of the water tank.

[0014] In one embodiment, the delivery pump includes a centrifugal pump; the heat transfer medium includes water vapor.

[0015] The embodiments of this disclosure employ the above-described technical solution to treat caprolactam-containing vapors discharged from the casting strip system and pelletizing system, preventing the generation of large amounts of flue gas in the workshop and avoiding abnormal conditions such as strip vibration and strip breakage caused by caprolactam crystallizing and falling off in the workshop. Furthermore, by providing a heat transfer medium to the waste gas treatment device, caprolactam crystallization can be prevented from clogging the pipelines in the waste gas treatment device.

[0016] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this disclosure will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0017] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments according to this disclosure and should not be construed as limiting the scope of this disclosure.

[0018] Figure 1 A schematic diagram of an exhaust gas treatment apparatus according to an embodiment of the present disclosure is shown;

[0019] Figure 2 A schematic diagram of a water tank according to an embodiment of the present disclosure is shown.

[0020] Explanation of reference numerals in the attached drawings: 100-Venturi ejector; 200-Gas-liquid separator; 300-Water tank; 300a-First chamber; 300b-Second chamber; 301-Baffle; 302-First drum; 303-Drive motor; 304-Transmission belt; 305-Flexible filter screen; 400-Transfer pump; 401-First valve; 402-Fourth pipeline; 403-Fifth pipeline; 501-Second valve; 502-First pipeline; 601-Second pipeline; 602-Third valve; 603-Casting strip plate system; 701-Pelletizing system; 702-Third pipeline; 703-Fourth valve. Detailed Implementation

[0021] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0022] In related technologies, when the high-temperature strip discharged from the casting plate comes into contact with the low-temperature cooling water in the pelletizing system, a large amount of water vapor containing caprolactam is instantly generated. If the water vapor containing caprolactam is not treated, a large amount of flue gas will be generated in the workshop; moreover, caprolactam will crystallize into lumps and fall off. If the lumps hit the strip, it will cause abnormal conditions such as strip vibration and strip agglomeration, generating irregularly shaped particles, affecting the extraction effect, and may even cause the pelletizer in the pelletizing system to stop, generating a large amount of waste material.

[0023] To overcome the aforementioned problems, this embodiment provides an exhaust gas treatment device. Utilizing the negative pressure provided by a Venturi ejector, caprolactam-containing vapors discharged from the casting strip system and pelletizing system are drawn into the Venturi ejector pump. Caprolactam and other substances dissolve into the spray water within the Venturi ejector. The liquid in the gas-liquid mixture discharged from the Venturi ejector enters a water tank, and the water in the tank is pumped back to the Venturi ejector for recycling. This avoids the generation of large amounts of flue gas containing caprolactam from the casting strip system and pelletizing system in the workshop, and also prevents caprolactam from crystallizing and falling off, causing abnormal conditions such as strip vibration and strip breakage. Furthermore, by providing a heat transfer medium to the exhaust gas treatment device, caprolactam crystallization can be prevented from clogging the pipes within the device.

[0024] Figure 1 A schematic diagram of an exhaust gas treatment apparatus according to an embodiment of the present disclosure is shown. Figure 1As shown, the waste gas treatment device for nylon polymerization includes: a Venturi ejector 100, the input end of which is connected to the casting strip system 603 and the pelletizing system 701 respectively; a gas-liquid separator 200, which is connected to the output end of the Venturi ejector 100; one output end of the gas-liquid separator 200 is connected to the exhaust channel; a water tank 300, which is connected to the other output end of the gas-liquid separator 200; and a transfer pump 400. The input end of the delivery pump 400 is connected to the water tank 300, and the output end of the delivery pump 400 is connected to the input end of the Venturi injector 100 through the first valve 401; the second valve 501 and the first pipeline 502 are also connected. The second valve 501 is installed in the first pipeline 502, which is used to connect to the heat medium supply device and the input end of the Venturi injector 100. The second valve 501 is used to control the flow rate of the heat medium in the first pipeline 502.

[0025] Under the negative pressure of the Venturi ejector 100, exhaust gas from at least one of the casting strip system 603 and the pelletizing system 701 can enter the Venturi ejector 100. The gas-liquid mixture ejected from the Venturi ejector 100 enters the gas-liquid separator 200 for separation. The gas in the gas-liquid mixture is discharged from the exhaust channel, and the liquid in the gas-liquid mixture enters the water tank 300. When the first valve 401 is switched to the open state, water in the water tank 300 can be transported to the Venturi ejector 100 under the suction action of the transfer pump 400 to replenish the Venturi ejector 100. When the second valve 501 is switched to the open state and the opening degree of the second valve 501 is adjusted to the correct position, under the negative pressure of the Venturi ejector 100, the heat medium provided by the heat medium supply device enters the Venturi ejector 100 through the first pipeline 502.

[0026] The Venturi ejector 100 generates a negative pressure suction at its inlet, thereby drawing caprolactam-containing vapor (or caprolactam monomer) from the casting strip system 603 or pelletizing system 701 located on its inlet side into its chamber. Inside the Venturi ejector 100 chamber, the caprolactam-containing vapor mixes with water in the Venturi ejector 100 to obtain a gas-liquid mixture; wherein caprolactam is soluble in water. The Venturi ejector 100 then sprays the gas-liquid mixture into the gas-liquid separator 200.

[0027] The gas-liquid separator 200 is a separation device that uses centrifugal separation and wire mesh filtration to remove liquid. The gas-liquid separator 200 consists of a cylinder, a separator, a demister, a drain valve, and other components. The separator can be a separation structure that employs separation methods such as gravity settling, baffle separation, centrifugal separation, wire mesh separation, ultrafiltration, or packing separation.

[0028] The gas-liquid separator 200 has two output ends. One output end can be connected to an exhaust channel to discharge the separated gas (i.e., non-condensable gas); the other output end can be connected to a water tank 300 to transport the separated liquid to the water tank 300. The exhaust channel can be a flue, through which the gas discharged from one of the output ends of the gas-liquid separator 200 can be released into the atmosphere. The water tank 300 is used to store the liquid discharged from the gas-liquid separator 200, such as water containing dissolved caprolactam.

[0029] A transfer pump 400 is connected to the output end of the water tank 300. The output end of the transfer pump 400 can be connected to the input end of the Venturi ejector 100. A first valve 401 is connected between the output end of the transfer pump 400 and the input end of the Venturi ejector 100. The first valve 401 controls the connection or disconnection of the transfer pump 400 and the Venturi ejector 100. When the first valve 401 is open, water can pass through it, and the transfer pump 400 can pump water from the water tank 300 to the Venturi ejector 100, thereby achieving water recycling. When the first valve 401 is closed, water cannot pass through it, and the transfer pump 400 is disconnected from the Venturi ejector 100. Optionally, the transfer pump 400 may be a centrifugal pump; in other examples, the transfer pump 400 may also be a piston pump, screw pump, or gear pump, as long as it can pump water from the water tank 300 to the Venturi ejector 100. In addition, the transfer pump 400 can also pump water from the water tank 300 to the extraction system.

[0030] In the above example, the water entering the water tank 300 from the gas-liquid separator 200 contains caprolactam. The water containing caprolactam can be cooled in the water tank 300 to crystallize the caprolactam, making it easier to filter out the crystallized caprolactam and thus reduce the caprolactam content in the water pumped by the delivery pump 400.

[0031] In practice, the water containing caprolactam can be allowed to stand and cool in the water tank 300 for a preset time. Alternatively, a heat exchange pipeline can be installed in the water tank 300, or a cooling device can be installed below or to the side of the water tank 300 to cool the contents of the water tank 300.

[0032] To prevent caprolactam crystallization and subsequent blockage due to excessively low temperatures in the exhaust gas treatment system's piping, a first pipe 502 is connected to the input end of the Venturi injector 100. This first pipe 502 connects to a heat transfer medium supply device. A second valve 501 is connected to the first pipe 502, controlling the flow rate of the heat transfer medium within it. When the second valve 501 is closed, the flow rate of the heat transfer medium in the first pipe 502 is zero. When the second valve 501 is open, its opening can be adjusted to regulate the flow rate of the heat transfer medium in the first pipe 502. For example, if the exhaust gas from the casting strip system 603 or the pelletizing system 701 contains a high amount of caprolactam, there may be significant caprolactam crystallization in the exhaust gas treatment system's piping. Therefore, the opening of the second valve 501 can be increased to increase the flow rate of the heat transfer medium in the first pipe 502.

[0033] Optionally, steam can be used as the heat transfer medium. During the exhaust gas treatment process, the second valve 501 can be controlled to be open and at an appropriate degree. Under the negative pressure suction of the Venturi ejector 100, the steam can pass through the second valve 501 and the first pipeline 502 and enter the Venturi ejector pump. The Venturi ejector pump can then inject the steam into the gas-liquid separator 200 and finally discharge it into the water tank 300, thus maintaining the pipeline in the exhaust gas treatment device at a relatively high temperature. In other examples, the heat transfer medium can also be hot air or hot nitrogen, or other fluids with a temperature higher than the freezing point of caprolactam.

[0034] This example directly delivers steam to the first pipeline 502, the Venturi injector 100, and other pipelines. This not only helps maintain the temperature in the pipeline above the freezing point of caprolactam (69.2℃), but also allows caprolactam to dissolve in the steam, as caprolactam is miscible with water in any proportion. This prevents the caprolactam from crystallizing due to low temperatures and causing pipeline blockage, thus keeping the pipeline unobstructed. Furthermore, this example has lower construction costs and reduces the amount of engineering work required.

[0035] The exhaust gas treatment device provided in this embodiment can utilize the negative pressure provided by the Venturi ejector 100 to draw the caprolactam-containing vapor discharged from the casting strip system 603 and the pelletizing system 701 into the Venturi ejector 100. The caprolactam and other substances are dissolved in the spray water in the Venturi ejector 100. The gas-liquid mixture discharged from the Venturi ejector 100 can be discharged after separation, reducing the emission of VOCs (volatile organic compounds) in the exhaust gas. The liquid after separation of the gas-liquid mixture discharged from the Venturi ejector 100 can enter the water tank 300. The water in the water tank 300 is transported to the Venturi ejector 100 by the transfer pump 400 for recycling. In this way, it is possible to avoid the generation of a large amount of flue gas in the workshop by the caprolactam-containing vapor discharged from the casting strip system 603 and the pelletizing system 701, and to avoid abnormal conditions such as strip vibration and strip bridging caused by the crystallization and falling of caprolactam in the workshop. Furthermore, by providing a heat transfer medium to the waste gas treatment device, it is possible to prevent caprolactam from crystallizing in the pipes of the waste gas treatment device and clogging the pipes.

[0036] In some embodiments, the exhaust gas treatment device further includes: a second pipeline 601 connected to the casting strip system 603, the second pipeline 601 also connected to the first pipeline 502, and the connection point between the second pipeline 601 and the first pipeline 502 is located at the output end of the second valve 501; and a third valve 602 for controlling the connection or disconnection between the casting strip system 603 and the input end of the Venturi injector 100.

[0037] For example, the first pipeline 502 includes a first branch, a second branch, and a first connector. The first branch is connected to one of the inlets of the first connector, and the outlet of the first connector is connected to the second branch. The second branch can be connected to the inlet of the Venturi injector 100. The second valve 501 can be connected between the first branch and the first connector, or the second valve 501 can be connected in the first branch.

[0038] The second pipe 601 can also be connected to another inlet of the first connector; the second pipe 601 can be connected in parallel with the first branch. The third valve 602 can be installed in the second pipe 601 or in the second branch of the first pipe 502. When the third valve 602 is open, the exhaust gas in the casting strip system 603 can pass through the third valve 602 and through a portion of the branch of the first pipe 502 and enter the Venturi injector 100. When the third valve 602 is closed, the casting strip system 603 is disconnected from the first pipe 502, preventing fluid from flowing from the casting strip system 603 to the first pipe 502.

[0039] In some embodiments, the exhaust gas treatment device further includes: a third pipeline 702, which is connected to the pelletizing system 701 and also connected to the first pipeline 502, with the connection point between the third pipeline 702 and the first pipeline 502 located at the output end of the second valve 501; and a fourth valve 703, which is used to control the connection or disconnection between the pelletizing system 701 and the input end of the Venturi injector 100.

[0040] The first conduit 502 also includes a third branch, which connects the second branch to the input of the Venturi injector 100. The first conduit 502 also includes a second connector, one input of which is connected to the second branch, one output of which is connected to the third branch, and the other input of which is connected to the third conduit 702. The third conduit 702 can be connected in parallel with the second branch of the first conduit 502.

[0041] The fourth valve 703 can be installed in the third pipeline 702. When the fourth valve 703 is open, the exhaust gas discharged from the pelletizing system 701 can pass through the fourth valve 703, the third branch of the first pipeline 502, and enter the Venturi injector 100. When the fourth valve 703 is closed, the pelletizing system 701 and the Venturi injector 100 are disconnected, preventing the pelletizing system 701 from supplying fluid to the Venturi injector 100.

[0042] In some examples, the third valve 602 can be located in the second branch of the first pipeline 502, with the second valve 501 and the third valve 602 connected in series, allowing the heat medium passing through the second valve 501 to flow through the third valve 602. To ensure that the exhaust gases from the casting strip system and the pelletizing system 701 can be controlled separately, the third valve 602 is connected in parallel with the fourth valve 703.

[0043] In practice, the second valve 501 can be in a slightly open state, while the first valve 401, the third valve 602, and the fourth valve 703 can be in a normally open state.

[0044] In other examples, the pelletizing system 701 can also be connected to the Venturi injector 100 via the second pipe 601 and the third valve 602, and the casting strip system can also be connected to the Venturi injector 100 via the third pipe 702 and the fourth valve 703.

[0045] In some embodiments, the exhaust gas treatment device further includes: a fourth pipeline 402 connected between the output end of the delivery pump 400 and the input end of the venturi injector 100; and a first valve 401 disposed in the fourth pipeline 402.

[0046] To further improve the utilization rate of water in the water tank 300, the exhaust gas treatment device may also include: a fifth pipeline 403, which is connected between the fourth pipeline 402 and the extraction system, and the connection between the fifth pipeline 403 and the fourth pipeline 402 is located at the input end of the first valve 401.

[0047] The fourth pipeline 402 is also equipped with a third connector, which connects two adjacent branches in the fourth pipeline 402, and another interface of the third connector is also connected to the fifth pipeline 403. The third connector is located at the input end of the first valve 401.

[0048] Optionally, a fifth valve may be provided in the fifth pipeline 403, which is used to control the connection or disconnection between the delivery pump 400 and the extraction system.

[0049] In some embodiments, the Venturi injector 100 has a first input terminal (such as...) Figure 1 The middle input terminal located on the left) and the second input terminal (such as Figure 1 The first pipe 502 is connected to the first input terminal (located at the upper end), and the fourth pipe 402 is connected to the second input terminal, which helps to avoid interference between the fourth pipe 402 and the first pipe 502 of the Venturi injector 100.

[0050] In some examples, the exhaust gas treatment device further includes a pressure gauge and a controller. The pressure gauge is located at the second input terminal, and the pressure gauge, the delivery pump 400, and the first valve 401 are electrically connected to the controller. Based on the pressure information detected by the pressure gauge, the controller controls the frequency of the delivery pump 400 and the opening degree of the first valve 401. Specifically, when the pressure information detected by the pressure gauge indicates a low current pressure, the controller can control the opening degree of the first valve 401 to be relatively large and the frequency of the delivery pump 400 to be relatively high, thereby quickly supplying water to the Venturi injector 100. When the pressure information detected by the pressure gauge indicates a high current pressure, the controller can control the opening degree of the first valve 401 to be relatively small and the frequency of the delivery pump 400 to be relatively low, to facilitate precise control of the amount of water supplied to the Venturi injector 100.

[0051] In some embodiments, a partition 301 is provided in the water tank 300 to divide at least a portion of the space in the water tank 300 into a first chamber 300a and a second chamber 300b. The first chamber 300a is used to store cooling water or transport water, and the second chamber 300b is connected to the output end of the gas-liquid separator 200 and is also connected to the input end of the delivery pump 400.

[0052] For example, the water tank 300 includes a box body and a partition 301 disposed within the box body. The box body is columnar, and the partition 301 divides the space within the box body into a first chamber 300a and a second chamber 300b. The upper end of the partition 301 is lower than the upper end of the box body, and there is a predetermined distance between the upper surface of the partition 301 and the upper surface of the box body. Therefore, when the water level in the second chamber 300b is low, water in the first chamber 300a can overflow into the second chamber 300b, ensuring that the water level in the second chamber 300b meets usage requirements.

[0053] The first chamber 300a can be connected to process systems such as the casting strip system and pelletizing system 701, and is used to store cooling water or conveying water used in the process. The second chamber 300b is used to store water discharged from the gas-liquid separator 200 and to supply water to the Venturi ejector 100 or the extraction system. Optionally, the volume of the first chamber 300a can be larger than the volume of the second chamber 300b.

[0054] Optionally, the liquid in the second chamber 300b of the water tank 300 can be demineralized water or water. A reagent capable of adsorbing VOCs can also be added to the second chamber 300b of the water tank 300. The specific composition of the reagent can be set according to actual needs, as long as it can adsorb the VOCs in the water entering the second chamber 300b. The VOCs include caprolactam gas and its oligomers, which are miscible with water in any proportion.

[0055] Optionally, a plate-shaped filter screen can also be installed in the second chamber 300b of the water tank 300. The plate-shaped filter screen can be installed in a corresponding manner to the output port in the second chamber 300b that is connected to the transfer pump 400. The plate-shaped filter screen is used to filter the water flowing from the second chamber 300b to the transfer pump 400 to remove particulate matter such as crystals from the water.

[0056] like Figure 2 As shown, in some examples, a flexible filter screen 305 is provided at the end of the water tank 300. The flexible filter screen 305 is located at the top of the water tank 300 and is used to filter the water entering the water tank 300. Specifically, the flexible filter screen 305 can be located at the top of the second chamber 300b to filter the water discharged from the gas-liquid separator 200. Alternatively, the flexible filter screen 305 can be located at the top of the first chamber 300a and the top of the second chamber 300b to filter the water entering the first chamber 300a and the second chamber 300b respectively.

[0057] The exhaust gas treatment device also includes: a first drum 302, a drive motor 303, and a transmission belt 304. The first drum 302 is used to wind the flexible filter screen 305. The drive motor 303 is electrically connected to the controller in the exhaust gas treatment device. The drive motor 303 drives the flexible filter screen 305 toward the first drum 302 through the transmission belt 304, so that the first drum 302 winds the flexible filter screen, thereby updating the part of the flexible filter screen 305 located at the top of the water tank 300.

[0058] The first reel 302 can be an electric reel. The electric reel and drive motor 303 can be electrically connected to the controller respectively. The electric reel and drive motor 303 can be positioned close to the side of the water tank 300 to prevent them from interfering with the connection between the water tank 300 and other components. Optionally, the exhaust gas treatment device also includes a mounting box, in which the electric reel and drive motor 303 can be located for protection. The side of the mounting box facing the water tank 300 can have a first opening and a second opening. The first opening can be located above the second opening. The first opening is for a flexible filter screen 305 to pass through, and the second opening is for a transmission belt 304 to pass through. The flexible filter screen 305 can be made of non-woven fabric. The transmission belt 304 can be a track.

[0059] The drive belt 304 can be positioned close to opposite sides of the water tank 300 to prevent it from interfering with the connection between the water tank 300 and other components. The drive belt 304 is used to guide the flexible filter screen 305 to remain flat, and during the winding process, it also guides the flexible filter screen 305 toward the electric drum, facilitating the winding of the flexible filter screen 305 by the electric drum.

[0060] Additionally, a second roller can be provided on the side of the water tank 300 opposite to the first roller 302. The second roller is used to release the unused portion of the flexible filter screen 305; the first roller is used to wind up the used portion of the flexible filter screen. The cooperation of the first roller 302, the second roller, and the drive belt 304 helps to ensure that the portion of the flexible filter screen 305 located at the top of the water tank 300 remains taut.

[0061] During the exhaust gas treatment process, the controller can control the drive motor 303 to drive the transmission belt at preset time intervals, and control the first drum 302 to move, so as to wind up the flexible filter screen 305 currently located at the top of the water tank 300, and cause the second drum to release the flexible filter screen 305, so that the released part of the second drum is laid on the top of the water tank 300 to filter the water entering the water tank 300. The preset time interval can be 1 hour to 2 hours. The time for the drive motor 303 to drive the transmission belt 304 can be 15 seconds to 30 seconds, just enough to wind up the used part of the flexible filter screen 305.

[0062] The waste gas treatment device provided in this embodiment has a simple structure and is easy to operate and implement. It can dissolve caprolactam in the waste gas discharged from the casting strip system and pelletizing system in water and then recover it. The absorption process of caprolactam is completed in the Venturi injector, which can reduce the emission of VOCs in the waste gas. The use of Venturi injector and centrifugal pump for transportation is cheaper and more efficient than using a vacuum pump to suck it up and then send it into the absorption tower. At the same time, water vapor is introduced into the waste gas treatment device to prevent caprolactam from crystallizing in the pipeline, which can reduce construction costs. In other embodiments, the casting strip system and pelletizing system can also be replaced by other process systems.

[0063] Other components of the exhaust gas treatment device in the above embodiments can be adopted from various technical solutions that are now and will be known to those skilled in the art, and will not be described in detail here.

[0064] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "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 used only for the convenience of describing this disclosure 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 limitations on this disclosure.

[0065] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means two or more, unless otherwise explicitly specified.

[0066] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., 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, an electrical connection, or a communication 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. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0067] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0068] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements have been described above. Of course, these are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0069] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this disclosure, and these should all be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A waste gas treatment device for nylon polymerization, characterized in that, The waste gas treatment device includes: A venturi injector, the input end of which is connected to the casting strip system and the pelletizing system respectively; A gas-liquid separator is provided, wherein the gas-liquid separator is connected to the output end of the Venturi injector; one of the output ends of the gas-liquid separator is connected to an exhaust channel. A water tank is connected to another output end of the gas-liquid separator. Under the negative pressure of the Venturi injector, the exhaust gas discharged from at least one of the casting strip system and the pelletizing system can enter the Venturi injector. The gas-liquid mixture ejected by the Venturi injector enters the gas-liquid separator for separation. The separated gas is discharged from the exhaust channel, and the separated liquid enters the water tank. A delivery pump, the input end of which is connected to the water tank, and the output end of which is connected to the input end of the Venturi injector through a first valve; The second valve is disposed in the first pipeline, which is used to connect to the heat medium supply device and is also connected to the input end of the Venturi injector. The second valve is used to control the flow rate of the heat medium in the first pipeline.

2. The waste gas treatment device according to claim 1, characterized in that, Also includes: The second pipeline is connected to the cast strip plate system and is also connected to the first pipeline. The connection point between the second pipeline and the first pipeline is located at the output end of the second valve. The third valve is used to control the connection or disconnection between the cast strip system and the input end of the Venturi injector.

3. The waste gas treatment device according to claim 2, characterized in that, Also includes: The third pipeline is connected to the pelletizing system and is also connected to the first pipeline, with the connection point between the third pipeline and the first pipeline located at the output end of the second valve; The fourth valve is used to control the connection or disconnection between the pelletizing system and the input end of the Venturi injector.

4. The waste gas treatment device according to claim 3, characterized in that, The second valve is connected in series with the third valve; the third valve is connected in parallel with the fourth valve.

5. The waste gas treatment device according to claim 1, characterized in that, Also includes: The fourth pipeline is connected between the output end of the delivery pump and the input end of the Venturi injector; The first valve is installed in the fourth pipeline.

6. The waste gas treatment device according to claim 5, characterized in that, Also includes: The fifth pipeline is connected between the fourth pipeline and the extraction system, and the connection between the fifth pipeline and the fourth pipeline is located at the input end of the first valve.

7. The waste gas treatment device according to claim 5, characterized in that, The Venturi injector has a first input end and a second input end, the first pipeline is connected to the first input end, and the fourth pipeline is connected to the second input end; The waste gas treatment device further includes a pressure gauge and a controller. The pressure gauge is installed at the second input terminal, and the pressure gauge, the delivery pump, and the first valve are electrically connected to the controller.

8. The waste gas treatment device according to claim 1, characterized in that, The water tank is equipped with a partition, which is used to divide the space inside the water tank into a first chamber and a second chamber. The first chamber is used to store cooling water or transport water. The second chamber is connected to the output end of the gas-liquid separator and is also connected to the input end of the delivery pump.

9. The waste gas treatment device according to claim 1, characterized in that, A flexible filter screen is provided at the end of the water tank, and the flexible filter screen is located at the top of the water tank. The flexible filter screen is used to filter the water entering the water tank. The exhaust gas treatment device further includes: a first drum, a drive motor, and a transmission belt. The first drum is used to wind the flexible filter screen. The drive motor is electrically connected to the controller in the exhaust gas treatment device. The drive motor drives the flexible filter screen to move toward the first drum through the transmission belt, so that the first drum winds the flexible filter screen, thereby updating the portion of the flexible filter screen located at the top of the water tank.

10. The waste gas treatment device according to claim 1, characterized in that, The delivery pump includes a centrifugal pump; the heat transfer medium includes water vapor.

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