Spinning solution filtration and exhaust gas recovery system

Abstract

This utility model discloses a spinning solution filtration and exhaust gas recovery system, belonging to the field of spinning technology. The technical solution is as follows: the spinning solution filtration and exhaust gas recovery system includes a spinning solution tank, a first filter, a second filter, a condenser, a gas-liquid separator, an activated carbon adsorption tower, a catalytic oxidation furnace, and a controller, connected sequentially by pipelines. The spinning solution tank stores the spinning solution. The outlet of the spinning solution tank is connected to the inlet of the first filter via an inlet pipe. A screw pump is installed on the inlet pipe. Inlet valves are installed at the inlets of both the first and second filters. The screw pump pumps the spinning solution from the spinning solution tank into the first and second filters for filtration, removing impurities and large molecules from the spinning solution. This utility model significantly improves the efficiency of staged filtration, ensuring high purity of the spinning solution.

Description

Technical Field

[0001] This utility model belongs to the field of spinning technology, specifically relating to a spinning solution filtration and exhaust gas recovery system. Background Technology

[0002] Acrylic fiber possesses excellent properties such as softness, warmth retention, light resistance, and antibacterial properties, and is widely used in textiles, clothing, and home furnishings. With the improvement of people's living standards and the increasing demands for textile quality, the market has placed higher requirements on the performance of acrylic fibers, such as higher strength, better elasticity, and superior dyeing properties. This has spurred the continuous development and improvement of PAN solution spinning technology. Beyond traditional textile applications, PAN fibers also show great potential in high-performance fibers and carbon fiber precursors. Carbon fiber possesses excellent properties such as high strength, high modulus, and low density, and is widely used in aerospace, automotive, and sporting goods. PAN fiber is the main precursor for carbon fiber production; therefore, improving the quality of PAN solution spinning and producing high-performance PAN fiber precursors is crucial for the development of the carbon fiber industry.

[0003] PAN dope solutions often contain unreacted monomers, gel particles, and mechanical impurities after polymerization. The purity of the spinning dope solution directly affects fiber quality. Traditional spinning dope solution filtration systems mostly use a single-stage filtration structure, requiring frequent filter replacements, increasing downtime for maintenance, resulting in low filtration efficiency, and also causing exhaust gas pollution. Utility Model Content

[0004] This invention provides a spinning solution filtration and exhaust gas recovery system, which significantly improves the efficiency of staged filtration and ensures high purity of the spinning solution.

[0005] The technical solution of this utility model is as follows: The spinning solution filtration and tail gas recovery system includes a spinning solution tank, a first filter, a second filter, a condenser, a gas-liquid separator, an activated carbon adsorption tower, a catalytic oxidation furnace, and a controller, which are connected in sequence by pipelines. The spinning solution tank contains the spinning solution. The outlet of the spinning solution tank is connected to the inlet of the first filter through an inlet pipe. A screw pump is installed on the inlet pipe. Inlet valves are installed at the inlets of the first filter and the second filter. The screw pump pumps the spinning solution in the spinning solution tank into the first filter and the second filter for filtration, filtering out impurities and macromolecular substances in the spinning solution. The first filter includes a filter body, and the side wall of the filter body is provided with an inlet pipe and an outlet pipe. The inlet pipe and the outlet pipe are located on both sides of the filter body. The first filter is provided with a filter screen, which includes a first filter screen and a second filter screen. The first filter screen is horizontally arranged, and the second filter screen is inclined. The first filter screen is arranged above the second filter screen. The second filter includes a filter body two. The side wall of the filter body two is provided with an inlet pipe two and an outlet pipe two, located on opposite sides of the filter body two. The outlet pipe two and the inlet pipe two are connected by a pipe. The second filter is equipped with a filtration unit, which includes a guide plate, a filter element, and an ultrasonic transducer. The guide plate is located below the inlet pipe two. The filter element is located below the guide plate. The ultrasonic transducer is located below the filter element and is electrically connected to the controller. A differential pressure sensor is installed inside the filter body two and is electrically connected to the controller. The bottom of the filter body two is equipped with a sewage discharge pipe two, and the bottom of the filter body two is equipped with a backwash water inlet pipe. The end of the backwash water inlet pipe is equipped with a backwash water outlet. The first filter and the second filter are connected to the exhaust gas outlet pipe, which is connected to the air inlet of the condenser. The liquid phase outlet of the gas-liquid separator is connected to the spinning doss reactor through the liquid phase recovery pipe. The discharge pipe two is connected to the spinning doss storage tank. The condenser is connected to a circulating water inlet pipe and a circulating water outlet pipe; The catalytic oxidation furnace is connected to a gas outlet pipeline.

[0006] Preferably, the first filter is further provided with a cleaning mechanism, which includes an inlet pipe at the top of the first filter, an outlet of the inlet pipe connected to a water distributor, and a drain pipe at the bottom of the first filter, with a drain valve installed on the drain pipe.

[0007] Preferably, the guide plate is provided with a guide grid, and the surface of the filter element is wavy.

[0008] Preferably, the backwash water outlet is connected to a funnel-shaped water nozzle.

[0009] Preferably, both the first filter and the second filter are provided with a housing, the housing is provided with a double-layer jacket, and both the first filter and the second filter are provided with a temperature sensor, which is electrically connected to the controller.

[0010] Preferably, the acute angle formed between the second filter screen and the side wall of the first filter body is 45°-75°.

[0011] Compared with the prior art, this utility model has the following advantages: 1. This utility model employs a first filter and a second filter. The first filter uses a plain-weave filter screen and the second filter uses a twill-weave filter screen. The second filter uses an alumina ceramic membrane filter element to achieve a significant improvement in the graded filtration efficiency and ensure the high purity of the spinning solution.

[0012] 2. The filter screen in the first filter is flushed with water, while the second filter uses an ultrasonic transducer and backwash nozzle to improve the regeneration rate of the filter screen and filter element, extend their service life, and reduce production costs.

[0013] 3. Exhaust gas recovery enhances environmental benefits. The condenser and gas-liquid separator recover high-boiling-point organic compounds (DMF), reducing the load on subsequent treatment. The activated carbon adsorption tower adsorbs low-concentration VOCs, which are then concentrated and sent to the catalytic oxidation furnace. The catalytic oxidation furnace completely decomposes high-concentration VOCs into CO2 and H2O. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the spinning solution filtration and exhaust gas recovery system of this utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the first filter of this utility model.

[0016] Figure 3 This is a schematic diagram of the structure of the second filter of this utility model.

[0017] In the diagram, 1. Spinning solution tank; 2. First filter; 3. Second filter; 4. Condenser; 5. Gas-liquid separator; 6. Activated carbon adsorption tower; 7. Catalytic oxidation furnace; 8. Screw pump; 9. Filter body one; 10. Feed pipe one; 11. Discharge pipe one; 12. First filter screen; 13. Second filter screen; 14. Filter body two; 15. Feed pipe two; 16. Discharge pipe two; 17. Baffle plate; 18. Filter element; 19. Ultrasonic transducer; 20. Sewage pipe two; 21. Backwash water inlet pipe; 22. Gas outlet pipe; 23. Water inlet pipe one; 24. Water distributor; 25. Sewage pipe one; 26. Water nozzle; 27. Waste gas outlet pipe; 28. Liquid phase recovery pipe; 29. ​​Spinning solution storage tank. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model.

[0019] Example 1 like Figure 1-3 As shown, this embodiment provides a spinning solution filtration and tail gas recovery system. The spinning solution filtration and tail gas recovery system includes a spinning solution tank 1, a first filter 2, a second filter 3, a condenser 4, a gas-liquid separator 5, an activated carbon adsorption tower 6, a catalytic oxidation furnace 7, and a controller, which are connected in sequence through pipelines. The spinning solution tank 1 contains the spinning solution. The outlet of the spinning solution tank 1 is connected to the inlet of the first filter 2 through an inlet pipe. A screw pump 8 is installed on the inlet pipe. Inlet valves are installed at the inlets of the first filter 2 and the second filter 3. The screw pump 8 pumps the spinning solution in the spinning solution tank 1 into the first filter 2 and the second filter 3 for filtration, filtering out impurities and macromolecular substances in the spinning solution. The first filter 2 includes a filter body 9. The side wall of the filter body 9 is provided with an inlet pipe 10 and an outlet pipe 11, located on opposite sides of the filter body 9. The first filter 2 contains filter screens, including a first filter screen 12 and a second filter screen 13. The first filter screen 12 is horizontally positioned, and the second filter screen 13 is inclined, forming an acute angle of 45° with the side wall of the first filter body. The first filter screen 12 is positioned above the second filter screen 13. The first filter 2 also includes a cleaning mechanism, comprising a water inlet pipe 23 located at the top of the first filter 2, with its outlet connected to a water distributor 24. A drain pipe 25 is located at the bottom of the first filter 2, and a drain valve is installed on the drain pipe 25.

[0020] The second filter 3 includes a filter body 14. The sidewall of the filter body 14 is provided with an inlet pipe 15 and an outlet pipe 16, located on both sides of the filter body 14. The outlet pipe 11 and the inlet pipe 15 are connected by a pipe. The second filter 3 is equipped with a filtration unit, which includes a guide plate 17, a filter element 18, and an ultrasonic transducer 19. The guide plate 17 is located below the inlet pipe 15 and has a flow guide grid. The surface of the filter element 18 is corrugated and located below the guide plate 17. The ultrasonic transducer 19 is located below the filter element 18 and is electrically connected to the controller. A differential pressure sensor is installed inside the filter body 14 and is electrically connected to the controller. The bottom of filter body 214 is equipped with a drain pipe 20 and a backwash water inlet pipe 21. The end of the backwash water inlet pipe 21 is equipped with a backwash water outlet, which is connected to a funnel-shaped water nozzle 26. The condenser 4 is connected to a circulating water inlet pipe and a circulating water outlet pipe. The catalytic oxidation furnace is connected to a gas outlet pipe 22. The first filter 2 and the second filter 3 are connected to a waste gas outlet pipe 27, which is connected to the condenser's inlet. The liquid phase outlet of the gas-liquid separator 5 is connected to the spinning solution tank 1 via a liquid phase recovery pipe 28. The discharge pipe 216 is connected to the spinning solution storage tank 29. Both the first filter 2 and the second filter 3 are equipped with a housing, and the housing is provided with a double-layer jacket. Both the first filter 2 and the second filter 3 are equipped with a temperature sensor, and the temperature sensor is electrically connected to the controller.

[0021] Working process: The polyamide spinning solution in the spinning dosing tank 1 is pumped into the first filter 2 by a screw pump. The spinning solution passes sequentially through a first plain-weave filter screen and a second oblique-weave filter screen arranged at a 45° angle. Colloidal aggregates are separated by turbulence effect, and the trapped material is periodically discharged through the bottom drain valve. The pretreated spinning solution enters the second filter 3. The guide plate 17 evenly distributes the liquid flow to the corrugated filter element 18. When the differential pressure sensor detects the set differential pressure, the feed valve of the second feed pipe 15 is closed, the ultrasonic transducer 19 is activated, and the backwash water inlet pipe 21 backwashes through the horn-shaped water nozzle 26. Waste residue is periodically discharged through the second drain pipe. When the differential pressure drops to the normal operating set value, the feed valve of feed pipeline 15 is opened for normal filtration. The exhaust gas generated by the first filter 2 and the second filter 3 enters the condenser 4 and the gas-liquid separator 5 to recover high-boiling-point organic compounds (DMF), reducing the load on subsequent processing. The condensate (containing DMF) is pumped back to the spinning solution tank 1 for recycling. The non-condensable gas (containing acrylonitrile and methyl acrylate) enters the activated carbon adsorption tower 6 for secondary adsorption. The activated carbon adsorption tower 6 adsorbs low-concentration VOCs, concentrates them, and sends them to the catalytic oxidation furnace. The catalytic oxidation furnace completely decomposes high-concentration VOCs into CO2 and H2O and discharges them.

Claims

1. A system for the filtration of a spinning dope and the recovery of its off-gas, characterized in that, It includes a spinning solution tank (1), a first filter (2), a second filter (3), a condenser (4), a gas-liquid separator (5), an activated carbon adsorption tower (6), a catalytic oxidation furnace (7), and a controller, all connected in sequence by pipelines. The spinning solution tank (1) contains the spinning solution. The outlet of the spinning solution tank (1) is connected to the inlet of the first filter (2) through an inlet pipe. A screw pump (8) is installed on the inlet pipe. Inlet valves are installed at the inlets of the first filter (2) and the second filter (3). The screw pump (8) pumps the spinning solution in the spinning solution tank (1) into the first filter (2) and the second filter (3) for filtration, filtering out impurities and macromolecular substances in the spinning solution. The first filter (2) includes a filter body (9), and the side wall of the filter body (9) is provided with a feed pipe (10) and a discharge pipe (11). The feed pipe (10) and the discharge pipe (11) are located on both sides of the filter body (9). The first filter (2) is provided with a filter screen, which includes a first filter screen (12) and a second filter screen (13). The first filter screen (12) is horizontally arranged, and the second filter screen (13) is inclined. The first filter screen (12) is arranged above the second filter screen (13). The second filter (3) includes a filter body two (14), the side wall of the filter body two (14) is provided with a feed pipe two (15) and a discharge pipe two (16), the feed pipe two (15) and the discharge pipe two (16) are located on both sides of the filter body two (14), and the discharge pipe one (11) and the feed pipe two (15) are connected by a pipe; the second filter (3) is provided with a filter unit, the filter unit includes a guide plate (17), a filter element (18) and an ultrasonic transducer (19), the guide plate (17) is located below the feed pipe two (15); the filter element (18) is located below the guide plate (17); the ultrasonic transducer (19) is located below the filter element (18) and is electrically connected to the controller, a differential pressure sensor is provided in the filter body two (14), and the differential pressure sensor is electrically connected to the controller; The bottom of the filter body 2 (14) is provided with a sewage discharge pipe 2 (20), the bottom of the filter body 2 (14) is provided with a backwash water inlet pipe (21), and the end of the backwash water inlet pipe (21) is provided with a backwash water outlet; The condenser (4) is connected to a circulating water inlet pipe and a circulating water outlet pipe; the first filter (2) and the second filter (3) are connected to a waste gas outlet pipe (27), which is connected to the air inlet of the condenser; the liquid phase outlet of the gas-liquid separator (5) is connected to the spinning solution kettle (1) through a liquid phase recovery pipe (28); the second discharge pipe (16) is connected to the spinning solution storage tank (29); The catalytic oxidation furnace is connected to a gas outlet pipeline (22).

2. The dope filtration and its off gas recovery system according to claim 1, wherein, The first filter (2) is also equipped with a cleaning mechanism, which includes an inlet pipe (23) located at the top of the first filter (2), the outlet of the inlet pipe (23) is connected to a water distributor (24), and a drain pipe (25) is located at the bottom of the first filter (2), with a drain valve.

3. The spin dope filtration and its off gas recovery system of claim 1, wherein, The guide plate (17) is provided with a guide grid, and the surface of the filter element (18) is wavy.

4. The spin dope filtration and its off gas recovery system of claim 1, wherein, The backwash water outlet is connected to a funnel-shaped water nozzle (26).

5. The spin dope filtration and its off gas recovery system of claim 1, wherein, Both the first filter (2) and the second filter (3) are provided with a housing, and the housing is provided with a double-layer jacket. Both the first filter (2) and the second filter (3) are provided with a temperature sensor, and the temperature sensor is electrically connected to the controller.

6. The spin dope filtration and its off gas recovery system of claim 1, wherein, The acute angle formed between the second filter screen (13) and the side wall of the first filter (2) is 45°-75°.

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