Device for removing moisture and DMAC from exhaust gas
By introducing a gas condensation chamber and a demister chamber into the waste gas treatment device, and combining diversion, centrifugation and filtration demister components, the problems of low DMAC removal rate and wire mesh demister blockage in polyimide fiber production waste gas are solved, achieving efficient removal of moisture and DMAC and meeting emission standards.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU AOSHEN HI TECH MATERIALS CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-07-03
AI Technical Summary
In existing technologies, organic solvents such as DMAC in the waste gas generated during the production of polyimide fibers are difficult to be completely absorbed by the spray tower, and the wire mesh demister is prone to clogging, resulting in increased pressure drop, decreased treatment efficiency, and difficulty in meeting emission standards, especially for fine mist below 5μm with a removal rate of less than 50%.
It adopts a gas condensation chamber and a demister chamber structure inside the shell, combined with a diversion demister, a centrifugal separation demister and a filter demister. It forms droplets through cooling water, and uses centrifugal force and screen filtration to remove droplets of different particle sizes, thereby achieving efficient removal of moisture and DMAC from exhaust gas.
It improves demisting efficiency, increases droplet volume for easier removal, ensures that the exhaust gas flowing out of the outlet meets emission standards, and solves the problems of clogging and insufficient removal rate of wire mesh demisters.
Smart Images
Figure CN224442523U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water mist removal technology, specifically to a device for removing moisture and DMAC from exhaust gas. Background Technology
[0002] The waste gas generated during the cyclization process in polyimide fiber production is typically treated using a combined "condensation + spraying" process. During the spraying process, organic solvents such as DMAC in the waste gas cannot be completely absorbed due to the high gas velocity. Furthermore, when the gas and liquid come into contact within the spraying tower, the high-speed airflow carries tiny droplets, forming water mist. This water mist carries PM2.5 and residual organic solvents such as DMAC. To address this, a water mist demister, such as a wire mesh demister, is generally used. However, wire mesh demisters, with their dense structure formed by multiple layers of woven metal wire mesh, are easily clogged by particulate matter in the waste gas, leading to increased pressure drop and decreased treatment efficiency. Moreover, wire mesh demisters can only effectively capture droplets larger than 10µm, and their removal rate for fine mist smaller than 5µm is less than 50%, making it difficult to meet emission standards. Utility Model Content
[0003] The main objective of this invention is to provide a device for removing moisture and DMAC from exhaust gas, aiming to solve the aforementioned problems.
[0004] To achieve the above objectives, this utility model proposes a device for removing moisture and DMAC from waste gas, comprising:
[0005] The housing includes a gas condensation chamber and a demister chamber. The gas condensation chamber is fitted around the outer periphery of the demister chamber and contains cooling water for cooling mist droplets in the exhaust gas inside the housing to form liquid droplets. The demister chamber is sequentially arranged along a first direction with a connected air inlet zone, a centrifugal desmearing zone, and an air outlet zone. The housing has an air inlet and an air outlet. The air inlet is located corresponding to and communicates with the air inlet zone to allow the exhaust gas to be treated to enter the air inlet zone. The air outlet is located corresponding to and communicates with the air outlet zone to allow the treated exhaust gas in the air outlet zone to flow out of the housing.
[0006] The demisting assembly includes a flow-diverting demisting component, a centrifugal separation demisting component, and a filter demisting component. The flow-diverting demisting component is located at the first end of the centrifugal demisting zone near the air inlet zone and is used to divert exhaust gas and trap large-diameter droplets. The centrifugal separation demisting component is located within the centrifugal demisting zone and is used to centrifugally separate gas and droplets in the exhaust gas. The filter demisting component is located at the second end of the centrifugal demisting zone near the air outlet zone and is used to trap small-diameter droplets.
[0007] Optionally, the flow splitter and demisting component is a flow splitter plate.
[0008] Optionally, the centrifugal separation demister includes:
[0009] Multiple fan blades are spaced apart along the first direction in the center of the centrifugal de-misting zone, and each fan blade is rotatable relative to the housing about its axis; and,
[0010] Multiple screens are spaced apart and fitted around the outer periphery of the multiple fan blades, and are distributed at intervals along the first direction, and are alternately arranged with the multiple fan blades along the first direction.
[0011] Optionally, the mesh count of each of the sieves is greater than or equal to 20 mesh and less than or equal to 100 mesh.
[0012] Optionally, the demisting component further includes:
[0013] A drive shaft is disposed within the housing and extends along the first direction. The input end of the drive shaft penetrates one side wall of the housing in the first direction. A plurality of fan blades are sleeved around the drive shaft.
[0014] A drive unit is disposed in the housing and is driven to the input end of the transmission shaft to drive the transmission shaft to rotate relative to the housing about its axis, so that the transmission shaft drives the plurality of fan blades to rotate.
[0015] Optionally, the filtration and demisting element includes at least one filter screen.
[0016] Optionally, the filtration and demisting component includes a plurality of filter screens, the mesh size of which increases sequentially in the direction toward the air outlet zone.
[0017] Optionally, the housing further includes a liquid storage chamber located below and connected to the demister chamber.
[0018] Optionally, a drain outlet is provided on one side wall of the liquid storage chamber, and a drain pipe is installed on the drain outlet;
[0019] The device for removing moisture and DMAC from exhaust gas also includes:
[0020] A level transmitter, disposed in the liquid storage chamber, is used to measure the liquid level of droplets within the liquid storage chamber; and,
[0021] A drain shielded pump is installed on the drain pipe.
[0022] Optionally, the device for removing moisture and DMAC from exhaust gas further includes a thermometer disposed in the housing for measuring the temperature inside the housing.
[0023] In the technical solution of this utility model, by introducing cooling water into the gas condensation chamber, the mist droplets in the exhaust gas inside the shell can be cooled to form liquid droplets, which also reduces the ability of the exhaust gas to carry liquid droplets and solid particles, which is beneficial to improving the demisting efficiency. It can also increase the volume of liquid droplets in the demisting chamber for easy removal. In the demisting chamber, large-diameter liquid droplets in the exhaust gas are removed sequentially by the diversion demisting device, gas and liquid droplets in the exhaust gas are separated by centrifugal separation demisting device, and small-diameter liquid droplets are removed by the filtration demisting device, so as to achieve efficient removal of moisture and DMAC in the exhaust gas, and the exhaust gas flowing out of the outlet meets the emission standards. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0025] Figure 1 This is a cross-sectional view of an embodiment of the device for removing moisture and DMAC from exhaust gas provided by the present invention.
[0026] Figure 2 for Figure 1 Another cross-sectional view of the device used for removing moisture and DMAC from exhaust gas.
[0027] Explanation of icon numbers:
[0028]
[0029]
[0030] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0032] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.
[0033] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0034] The waste gas generated during the cyclization process in polyimide fiber production is typically treated using a combined "condensation + spraying" process. During the spraying process, organic solvents such as DMAC in the waste gas cannot be completely absorbed due to the high gas velocity. Furthermore, when the gas and liquid come into contact within the spraying tower, the high-speed airflow carries tiny droplets, forming water mist. This water mist carries PM2.5 and residual organic solvents such as DMAC. To address this, a water mist demister, such as a wire mesh demister, is generally used. However, wire mesh demisters, with their dense structure formed by multiple layers of woven metal wire mesh, are easily clogged by particulate matter in the waste gas, leading to increased pressure drop and decreased treatment efficiency. Moreover, wire mesh demisters can only effectively capture droplets larger than 10µm, and their removal rate for fine mist smaller than 5µm is less than 50%, making it difficult to meet emission standards.
[0035] In view of this, the present invention provides a device 100 for removing moisture and DMAC from exhaust gas. Figure 1 and Figure 2 This is an embodiment of the device 100 for removing moisture and DMAC from exhaust gas provided by this utility model.
[0036] Please see Figure 1 and Figure 2The device 100 for removing moisture and DMAC from exhaust gas includes a housing 1 and a demisting assembly 2. The housing 1 includes a gas condensation chamber 11 and a demisting chamber 12. The gas condensation chamber 11 is fitted around the outer periphery of the demisting chamber 12 and contains cooling water to cool the mist droplets in the exhaust gas inside the housing 1, forming liquid droplets. The demisting chamber 12 is sequentially arranged along a first direction with a connected air inlet zone 121, a centrifugal demisting zone 122, and an air outlet zone 123. The housing 1 has an air inlet 1211 and an air outlet 1231. The air inlet 1211 is located corresponding to and communicates with the air inlet zone 121 to allow the exhaust gas to enter the air inlet zone 121. The air outlet 1231 is provided corresponding to and communicates with the air outlet area 123 so that the treated waste gas in the air outlet area 123 can flow to the outside of the housing 1. The demisting component 2 includes a diversion demisting element 21, a centrifugal separation demisting element 22, and a filter demisting element 23. The diversion demisting element 21 is provided at the first end of the centrifugal demisting area 122 near the air inlet area 121 and is used to divert waste gas and intercept large-diameter droplets. The centrifugal separation demisting element 22 is provided in the centrifugal demisting area 122 and is used to centrifugally separate gas and droplets in the waste gas. The filter demisting element 23 is provided at the second end of the centrifugal demisting area 122 near the air outlet area 123 and is used to intercept small-diameter droplets.
[0037] In this utility model, by introducing cooling water into the gas condensation chamber 11, the mist droplets in the exhaust gas inside the shell 1 can be cooled to form liquid droplets, which also reduces the ability of the exhaust gas to carry liquid droplets and solid particles, thus improving the demisting efficiency. Furthermore, it increases the volume of liquid droplets in the demisting chamber 12 for easier removal. Within the demisting chamber 12, large-diameter liquid droplets in the exhaust gas are removed sequentially by the diversion demisting component 21, the gas and liquid droplets in the exhaust gas are separated by centrifugal separation demisting component 22, and small-diameter liquid droplets are removed by the filtration demisting component 23. This achieves efficient removal of moisture and DMAC from the exhaust gas, ensuring that the exhaust gas flowing out through the outlet 1231 meets emission standards.
[0038] It should be noted that, in one embodiment of this utility model, the temperature of the cooling water introduced into the gas condensation chamber 11 is 6℃-10℃, so that the temperature inside the shell 1 reaches 8℃-12℃. This allows the mist droplets in the exhaust gas inside the shell 1 to be cooled into liquid droplets, and also increases the volume of the liquid droplets inside the demister 12. For more details, please refer to... Figure 1 The device 100 for removing moisture and DMAC from exhaust gas also includes a thermometer 6, which is installed in the housing 1 and used to measure the temperature inside the housing 1. Thus, when the temperature inside the housing 1 drops to 8℃-12℃, the exhaust gas to be treated is then introduced into the demister 12 to ensure that the mist droplets in the exhaust gas can be cooled into liquid droplets.
[0039] It should also be noted that the gas condensation chamber 11 is equipped with a water inlet pipe and a water outlet pipe, the water inlet pipe is equipped with a water inlet valve, and the water outlet pipe is equipped with a water outlet valve.
[0040] It should also be noted that, in this invention, the large-diameter droplets are droplets with a diameter of 10 μm or more, and the small-diameter droplets are droplets with a diameter of less than 5 μm.
[0041] Further, please refer to Figure 1 The flow divider demister 21 is a flow divider plate 211; thus, the exhaust gas entering the air inlet zone 121 and the small-diameter droplets formed by cooling are diverted by the flow divider plate 211 and uniformly enter the centrifugal demisting zone 122, with the same direction and reduced flow velocity. At the same time, the large-diameter droplets formed by cooling are intercepted by the flow divider demister 21, realizing the removal of large-diameter droplets, that is, completing the initial demisting.
[0042] For details, please refer to Figure 1 and Figure 2 The centrifugal demisting component 22 includes multiple fan blades 221 and multiple screens 222. The multiple fan blades 221 are distributed at intervals along the first direction in the middle of the centrifugal demisting zone 122. Each fan blade 221 can rotate relative to the housing 1 around its axis. The multiple screens 222 are spaced around the outer periphery of the multiple fan blades 221 and are distributed at intervals along the first direction, and are alternately arranged with the multiple fan blades 221 along the first direction.
[0043] Thus, as the fan blades 221 rotate, the exhaust gas flowing into the centrifugal demisting zone 122 generates centrifugal force, causing it to collide with the inner wall of the centrifugal demisting zone 122 and the screen 222 to form droplets, which then deposit and form condensate that flows downwards, completing secondary demisting. Simultaneously, multiple fan blades 221 and multiple screens 222 are arranged alternately along the first direction, forming an air duct between the fan blades 221 and the screens 222, which reduces wind resistance.
[0044] More specifically, each of the fan blades 221 includes six blades, which are evenly spaced along the circumference of the fan blade 221. Each blade is perpendicular to the two side walls of the housing 1 in the first direction and parallel to the axis extending along the first direction. Thus, under the action of the fan blades 221, the direction of exhaust gas movement forms an angle of 50°-70° with the inner wall of the centrifugal dewatering zone 122, causing the exhaust gas to collide with the inner wall of the centrifugal dewatering zone 122 and the screen 222.
[0045] Furthermore, the mesh count of each of the sieves 222 is greater than or equal to 20 mesh and less than or equal to 100 mesh.
[0046] For details, please refer to Figure 1 and Figure 2 The demisting assembly 2 further includes a drive shaft 24 and a drive member 25. The drive shaft 24 is disposed inside the housing 1 and extends along the first direction. The input end of the drive shaft 24 penetrates one side wall of the housing 1 in the first direction. A plurality of fan blades 221 are sleeved on the outside of the drive shaft 24. The drive member 25 is disposed in the housing 1 and is drivenly connected to the input end of the drive shaft 24 to drive the drive shaft 24 to rotate relative to the housing 1 around its axis, so that the drive shaft 24 drives the plurality of fan blades 221 to rotate. More specifically, the input end of the drive shaft 24 is sealed to the housing 1.
[0047] Furthermore, in one embodiment of this utility model, the driving component 25 is a drive motor. More specifically, the output shaft of the drive motor is connected to the input shaft bearing of the transmission shaft 24.
[0048] For details, please refer to Figure 1 The filtration and demisting component 23 includes at least one filter screen 231. Thus, small-diameter droplets are filtered through the filter screen 231, completing three stages of demisting.
[0049] Furthermore, the filter and demisting component 23 includes a plurality of filter screens 231, the mesh size of the plurality of filter screens 231 increasing sequentially in the direction toward the air outlet zone 123, so as to effectively trap small-diameter droplets and improve the demisting rate.
[0050] For details, please refer to Figure 1 and Figure 2 The housing 1 also includes a liquid storage chamber 13, which is located below and connected to the demister chamber 12. Thus, large-diameter droplets collected by the diverter plate 211, condensate collected by the inner wall of the centrifugal demisting zone 122 and the screen 222, and small-diameter droplets collected by the filter screen 231 all flow down to the liquid storage chamber 13 under gravity for collection.
[0051] More specifically, the lower end of the liquid outlet chamber is funnel-shaped, and the liquid outlet 131 is located at the lower end of the liquid outlet chamber to facilitate droplet collection.
[0052] Further, please refer to Figure 1 and Figure 2The storage chamber 13 has a drain port 131 on one side wall, and a drain pipe 3 is installed on the drain port 131. The device 100 for removing moisture and DMAC from waste gas also includes a level transmitter 4 and a drain shielded pump 5. The level transmitter 4 is located in the storage chamber 13 and is used to measure the level of droplets in the storage chamber 13. The drain shielded pump 5 is located in the drain pipe 3. Thus, when the level transmitter 4 detects that the liquid level in the storage chamber 13 reaches a preset height, the drain shielded pump 5 is turned on to discharge the droplets. When the level transmitter 4 detects that the liquid level in the storage chamber 13 is lower than the preset height, the drain shielded pump 5 is turned off to collect the droplets.
[0053] More specifically, the device 100 for removing moisture and DMAC from exhaust gas also includes a controller, which is electrically connected to the level transmitter 4 and the drain shielded pump 5 to control the operating state of the drain shielded pump 5 according to the measurement result of the level transmitter 4.
[0054] For details, please refer to Figure 1 and Figure 2 The liquid storage pipe is equipped with a drain valve 7, which is located between the drain shielded pump 5 and the drain port 131.
[0055] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. A device for removing water and DMAC from exhaust gas, characterized in that, The device for removing moisture and DMAC from exhaust gas includes: The housing includes a gas condensation chamber and a demister chamber. The gas condensation chamber is fitted around the outer periphery of the demister chamber and contains cooling water for cooling mist droplets in the exhaust gas inside the housing to form liquid droplets. The demister chamber is sequentially arranged along a first direction with a connected air inlet zone, a centrifugal desmearing zone, and an air outlet zone. The housing has an air inlet and an air outlet. The air inlet is located corresponding to and communicates with the air inlet zone to allow the exhaust gas to be treated to enter the air inlet zone. The air outlet is located corresponding to and communicates with the air outlet zone to allow the treated exhaust gas in the air outlet zone to flow out of the housing. The demisting assembly includes a flow-diverting demisting component, a centrifugal separation demisting component, and a filter demisting component. The flow-diverting demisting component is located at the first end of the centrifugal demisting zone near the air inlet zone and is used to divert exhaust gas and trap large-diameter droplets. The centrifugal separation demisting component is located within the centrifugal demisting zone and is used to centrifugally separate gas and droplets in the exhaust gas. The filter demisting component is located at the second end of the centrifugal demisting zone near the air outlet zone and is used to trap small-diameter droplets.
2. The apparatus for removing water and DMAC from exhaust gas according to claim 1, wherein The flow divider and demisting component is a flow divider plate.
3. The apparatus for removing water and DMAC from exhaust gas according to claim 1, wherein The centrifugal separation demister includes: Multiple fan blades are spaced apart along the first direction in the center of the centrifugal de-misting zone, and each fan blade is rotatable relative to the housing about its axis; and, Multiple screens are spaced apart and fitted around the outer periphery of the multiple fan blades, and are distributed at intervals along the first direction, and are alternately arranged with the multiple fan blades along the first direction.
4. The apparatus for removing water and DMAC from exhaust gas according to claim 3, wherein Each of the aforementioned sieves has a mesh size greater than or equal to 20 mesh and less than or equal to 100 mesh.
5. The apparatus for removing water and DMAC from exhaust gas according to claim 3, wherein The demisting component also includes: A drive shaft is disposed within the housing and extends along the first direction. The input end of the drive shaft penetrates one side wall of the housing in the first direction. A plurality of fan blades are sleeved around the drive shaft. A drive unit is disposed in the housing and is driven to the input end of the transmission shaft to drive the transmission shaft to rotate relative to the housing about its axis, so that the transmission shaft drives the plurality of fan blades to rotate.
6. The apparatus for removing water and DMAC from exhaust gas according to claim 1, wherein The filtration and demisting component includes at least one filter screen.
7. The apparatus for removing water and DMAC from exhaust gas according to claim 6, wherein The filtration and demisting component includes a plurality of filter screens, the mesh size of which increases sequentially in the direction toward the air outlet area.
8. The apparatus for removing water and DMAC from exhaust gas according to claim 1, wherein The housing also includes a liquid storage chamber, which is located below the demister and is connected to the demister.
9. The apparatus for removing water and DMAC from exhaust gas according to claim 8, wherein A drain outlet is provided on one side wall of the liquid storage chamber, and a drain pipe is installed on the drain outlet; The device for removing moisture and DMAC from exhaust gas also includes: A level transmitter, disposed in the liquid storage chamber, is used to measure the liquid level of droplets within the liquid storage chamber; and, A drain shielded pump is installed on the drain pipe.
10. The apparatus for removing water and DMAC from exhaust gas according to claim 1, wherein The device for removing moisture and DMAC from exhaust gas also includes a thermometer, which is located in the housing and is used to measure the temperature inside the housing.