Device for uniformly conveying spinning solution at constant temperature

Abstract

The invention provides a device for uniformly conveying a spinning stock solution at a constant temperature. The device comprises a stock solution conveying system, a double-layer special-shaped jacket stock solution pipe, an iron removal filtering system and a heat preservation water system, the double-layer special-shaped jacket stock solution pipe is divided into an inner-layer pipe, an inner-layer pipe and an outer-layer pipe; the inner-layer pipe is used for stock solution flowing, and the outer-layer pipe is used for heat preservation water flowing; one end of the inner-layer pipe is connected into a stock solution conveying system, the other end of the inner-layer pipe is connected with an iron removal filtering system, the outer-layer heat preservation water flowing pipeline is connected into a heat preservation water system for circulation, and then heat preservation of stock solution in the inner-layer stock solution flowing pipeline is achieved. Compared with the prior art, the constant-temperature uniformity in the material stock solution conveying process is achieved, the pressure influence of gel and impurities on the stock solution filter is reduced through the multi-stage filtering effect of the staggered filter screens and the iron removal filter in the double-layer special-shaped jacket stock solution pipe on materials, the service life of the stock solution filter is prolonged, and the working efficiency of the stock solution filter is improved. The head stretching rate of the spinneret plate is guaranteed, and the spinning stability is further improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of dope conveying in the production process of polyacrylonitrile carbon fiber precursor, in particular to design a device for conveying dope, filtering the dope and ensuring constant temperature and uniformity in the process of dope transportation. BACKGROUND

[0002] When the precursor is produced by dry-jet wet spinning method, acrylonitrile is pumped to the spinning machine for spinning after the dosing and reaction in the polymerization section are completed. The dope is conveyed in the pipeline, and the flow rate of the material in the pipe wall and the center is different due to the influence of temperature and the like. The gel is easily formed in the pipe wall. At the same time, a large amount of rust impurities is accumulated in the pipeline due to long-term operation of the material. The non-uniformity of the material and the influence of impurities cause the high pressure of the precursor head dope filter, the easy slurry drop of the spinneret, the low spinning success rate, the high number of broken filaments, and the extremely unstable operation. In order to solve the problem, a dope conveying device and method with constant temperature and uniformity and iron removal filtering function are invented. SUMMARY

[0003] The purpose of the present application is to provide a device for constant temperature and uniformity of spinning dope conveying. Through the design of the heat preservation system and the double-layer special-shaped jacketed dope pipe, the problems of non-uniformity of the dope conveying temperature, gel formation in the material, and a large number of impurities in the existing polyacrylonitrile precursor production process are solved. In turn, the problems of high pressure of the precursor head dope filter, easy slurry drop of the spinneret, low spinning success rate, high number of broken filaments, and the like are solved, and the stability of the precursor operation is improved.

[0004] The technical solution for achieving the purpose of the present application is a device for constant temperature and uniformity of spinning dope conveying, characterized in that it comprises a dope conveying system, a double-layer special-shaped jacketed dope pipe, an iron removal filtering system, and a heat preservation water system. The double-layer special-shaped jacketed dope pipe is divided into an inner layer pipe and an outer layer pipe. The inner layer pipe is used for the flow of the dope, and the outer layer pipe is used for the flow of the heat preservation water. One end of the inner layer pipe is connected to the dope conveying system, and the other end is connected to the iron removal filtering system. The outer layer heat preservation water flow pipeline is connected to the heat preservation water system for circulation, thereby realizing the heat preservation of the dope in the inner layer dope flow pipeline.

[0005] Further, the pipe wall of the inner layer pipe of the double-layer special-shaped jacketed dope pipe is in a slanted U-shaped structure, the U-shaped structure protrudes inward, there is a smooth chamfer between the U-shaped structures, the gel dead angle is avoided, the dope conveying direction is consistent with the pipe wall, and the pipe wall and the center are staggered at an angle of 135°. When the dope flows in the inner layer pipe, a small vortex is formed inside due to the blocking of the U-shaped structure, the circulation uniformity is better, and the gel formation is avoided. The heat preservation water in the outer layer pipe extends to the inward U-shaped structure, the heat preservation water preserves the center part of the dope, and the temperature difference between the pipe wall and the center part is reduced.

[0006] Further, the metal filter screen is arranged between the zigzag-shaped structures of the inner layer pipe to filter the gel and impurities in the raw liquid, and the filter screen is separately cleaned after being removed when the pipeline is cleaned.

[0007] Further, in the layer-shaped jacketed raw liquid pipe, the flow directions of the raw liquid in the inner layer raw liquid flow pipeline and the heat preservation water in the outer layer heat preservation water flow pipeline are opposite, so as to ensure the uniformity and consistency of the raw liquid temperature, and the system of the pipeline and the heat preservation water storage tank is closed and circulated, the opposite flow direction of the cut-off in the special-shaped inner pipe and the heat preservation water can maximize the raw liquid heat exchange efficiency, and the adjustment of the heat preservation water outlet temperature can realize the adjustment of the raw liquid temperature in the raw liquid conveying process.

[0008] Further, the heat preservation water system comprises a heat preservation water storage tank, a heat preservation water conveying pump and a heat preservation water heat exchanger; the heat preservation water storage tank is connected with the heat preservation water conveying pump through valves and pipelines, the heat preservation water conveying pump is connected with the heat preservation water heat exchanger through valves and pipelines, and the two ends of the heat preservation water system are connected with the outer layer heat preservation water flow pipeline in the double-layer special-shaped jacketed raw liquid pipe, so as to form a heat preservation water circulation.

[0009] Further, the raw liquid conveying system comprises a raw liquid storage tank and a raw liquid conveying pump; the raw liquid storage tank is connected with the raw liquid conveying pump through valves and pipelines, and the raw liquid conveying pump is connected with the inner layer pipe of the double-layer special-shaped jacketed raw liquid pipe through valves and pipelines.

[0010] Further, the iron removal filter system comprises an iron removal filter and a raw liquid filter; the raw liquid filter is connected with the iron removal filter, and then the impurities in the raw liquid are filtered.

[0011] Further, the temperature sensor and the pressure sensor are arranged at the raw liquid outflow end of the inner layer pipe of the double-layer special-shaped jacketed raw liquid pipe, so as to detect the temperature and pressure of the raw liquid in real time, to judge the viscosity fluctuation trend of the material according to the temperature and pressure value changes, to timely adjust the heat preservation water temperature in the heat preservation water system, to reduce the material fluctuation, and to improve the stability of the raw silk production line.

[0012] Further, the inner layer pipe of the double-layer special-shaped jacketed raw liquid pipe is a two-semicircle combined type, the semicircle pipes are fixedly connected, and the raw liquid flow pipelines of the two inner layer pipes are switched for standby, so as to facilitate the disassembly and cleaning.

[0013] Further, an iron removal filter is additionally arranged before the raw liquid is conveyed to the raw liquid filter, for standby.

[0014] Compared with the prior art, the present application has the following advantages:

[0015] (1) The design of the heat preservation water system and the double-layer special-shaped jacketed raw liquid pipe in the present application can control the raw liquid temperature constant and uniform, and the temperature of the pipe wall and the center is consistent, so as to reduce the generation of material gel and improve the industrial applicability.

[0016] (2) The inner layer of the double-layer irregular jacketed raw liquid tube in this invention is closed by a uniformly arranged "zigzag" structure, which makes the raw liquid flow in the inner tube and form small vortices due to the obstruction of the zigzag structure, thus improving the uniformity of the raw liquid.

[0017] (3) The inner tube and the iron removal filter designed in this invention are used in pairs and can be switched and cleaned according to the production situation. The operation is convenient and the normal production is not affected during the switching and cleaning.

[0018] (4) In this invention, the outlet end of the inner layer raw liquid flow pipeline is equipped with a temperature sensor and a pressure sensor to detect the raw liquid temperature and pressure in real time. Based on the changes in temperature and pressure values, the fluctuation trend of material viscosity and other properties can be judged, and the temperature can be adjusted in time to reduce material fluctuations, thereby improving the stability of the raw silk production line.

[0019] To more clearly illustrate the functional characteristics and structural parameters of the present invention, further explanation is provided below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0020] Figure 1 A schematic diagram of a device for uniformly conveying spinning solution at a constant temperature;

[0021] Figure 2 The specific structure of the double-jacketed irregular-shaped raw liquid delivery pipeline.

[0022] Attached reference numerals: 1-Insulated water storage tank, 2-Insulated water transfer pump, 3-Insulated water heat exchanger, 4-Crude liquid storage tank, 5-Crude liquid transfer pump, 6-Double-layer irregular jacketed crude liquid pipe, 7-Iron removal filter, 8-Crude liquid filter. Detailed Implementation

[0023] The terminology used in this invention is for illustrative purposes only and is not intended to limit the invention. The following description, in conjunction with the appendix, further clarifies this concept. Figures 1-2 The following is a detailed description of some embodiments of the present invention.

[0024] The invention will be further described below with reference to specific implementation examples:

[0025] like Figure 1 As shown, a device for constant-temperature and uniform delivery of spinning solution includes a solution delivery system, a double-layer shaped jacketed solution pipe 6, an iron removal and filtration system, and a heat-insulating water system. The solution delivery system is used to deliver the solution, the iron removal and filtration system is used to remove iron from the solution, and the heat-insulating water system is used to keep the solution at a constant temperature.

[0026] Raw material delivery system: including raw material storage tank 4 and raw material delivery pump 5;

[0027] The raw solution storage tank 4 is connected with the raw solution delivery pump 5 through a valve and a pipeline, and the raw solution delivery pump 5 is connected with the double-layer special-shaped jacketed raw solution pipe 6 through a valve and a pipeline.

[0028] The double-layer special-shaped jacketed raw solution pipe 6 is of a double-layer jacketed special-shaped structure, and specifically, as shown in the figure, Figure 2 the double-layer special-shaped jacketed raw solution pipe 6 comprises an inner layer pipe (a raw solution flow pipeline) and an outer layer pipe (a heat preservation water flow pipeline), the raw solution flow pipeline of the inner layer is connected with the iron removal filter 7 in the iron removal filtration system to perform iron removal filtration on the raw solution, and the heat preservation water flow pipeline of the outer layer is connected with the heat preservation water system to perform heat preservation on the raw solution.

[0029] The pipe wall of the inner layer pipe in the double-layer special-shaped jacketed raw solution pipe 6 is of a slanting U-shaped structure, the U-shaped structure protrudes inward, there is a smooth chamfer between the U-shaped structures, a gel dead angle is avoided, the raw solution delivery direction is consistent, and the U-shaped structures are uniformly staggered, so that when the raw solution flows in the inner layer pipe, small vortexes are formed inside due to the U-shaped structure, the circulation uniformity is better, and gel production is avoided.

[0030] The slanting U-shaped structure and the pipe wall form an angle of 110°-150°, the slanting direction of the U-shaped structure is consistent with the raw solution flow direction and forms a certain angle, which can reduce the resistance when the raw solution flows and reduce the risk of gel gathering on the pipe wall.

[0031] The heat preservation water in the outer layer pipe extends inward in the U-shaped structure, the heat preservation water can perform heat preservation on the central part of the raw solution, and the temperature difference between the pipe wall and the central part is reduced

[0032] The slanting U-shaped structures of the inner layer pipe are arranged with a detachable metal filter screen in a staggered manner, which is used for filtering gel and impurities in the raw solution, and the filter screen can be separately cleaned after being detached when the pipeline is cleaned.

[0033] The raw solution flow direction and the heat preservation water flow direction are opposite, the heat exchange efficiency can be maximized, the uniformity and consistency of the raw solution temperature can be ensured, the pipeline and the heat preservation water storage tank system are in closed circulation, the temperature of the raw solution during the delivery process can be adjusted by adjusting the outlet temperature of the heat preservation water.

[0034] The heat preservation water system comprises a heat preservation water storage tank 1, a heat preservation water delivery pump 2 and a heat preservation water heat exchanger 3, the heat preservation water storage tank 1 is connected with the heat preservation water delivery pump 2 through a valve and a pipeline, the heat preservation water delivery pump 2 is connected with the heat preservation water heat exchanger 3 through a valve and a pipeline, and the two ends of the heat preservation water system are connected with the outer layer heat preservation water flow pipeline in the double-layer special-shaped jacketed raw solution pipe 6 to form heat preservation water circulation.

[0035] The iron removal filtration system comprises an iron removal filter 7 and a raw solution filter 8, the raw solution filter 8 is connected with the iron removal filter 7, and then the raw solution with consistent and constant temperature and five impurities at the pipe wall and the central part is obtained.

[0036] The temperature sensor and the pressure sensor are arranged at the dope outflow end of the inner layer pipe of the double-layer special-shaped jacketed dope pipe 6, and are used for detecting the temperature and pressure of the dope in real time.

[0037] As another implementation, the inner layer pipe of the double-layer special-shaped jacketed dope pipe 6 is a two-semicircle combined type, and the semicircle pipes are fixedly connected, and the dope flow lines of the two inner layer pipes can be switched for standby, facilitating disassembly and cleaning.

[0038] As another implementation, before the dope is delivered to the filter 8, a set of dope iron removal filter 7 is additionally arranged, and one is used and the other is standby for timely replacement, and the more rust and impurities in the pipeline can reduce the pressure of the dope filter, and the two sets of dope iron removal filters are used alternately.

[0039] The working process of the device for uniformly delivering dope at constant temperature is as follows: the polyacrylonitrile material (dope) after completing the polymerization reaction is delivered to the spinning by a dope delivery pump, and is delivered through a double-layer jacketed special-shaped dope pipe 6. Figure 2 As shown in the figure, the special-shaped pipe passes through the spinning dope, and when the dope flows in the inner layer pipe, a small vortex is formed inside due to the blocking of the U-shaped structure, the uniformity of the dope is improved, and the staggered filter screen plays a preliminary filtering role on the final gel and impurities of the dope. The temperature of the heat preservation water is set to control the temperature of the dope delivery process, and the viscosity is adjusted to a certain extent.

[0040] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. A device for uniformly conveying spinning solution at a constant temperature, characterized in that, It includes a raw liquid delivery system, a double-layer shaped jacketed raw liquid pipe (6), an iron removal filtration system, and a heat preservation water system; the double-layer shaped jacketed raw liquid pipe (6) is divided into an inner pipe, an inner tube, and an outer pipe; the inner tube is used for raw liquid flow, and the outer tube is used for heat preservation water flow; one end of the inner tube is connected to the raw liquid delivery system, and the other end is connected to the iron removal filtration system, and the outer heat preservation water flow pipeline is connected to the heat preservation water system for circulation, thereby achieving heat preservation of the raw liquid in the inner raw liquid flow pipeline.

2. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 1, characterized in that, The inner tube of the double-layer irregular jacketed original liquid tube (6) has a slanted zigzag structure on its wall, with the zigzag protruding inward and rounded corners between the zigzags to avoid forming gel dead corners; The slanted Z-shaped structure extends in the same direction as the original liquid flow and is evenly and staggered. This allows the original liquid to form vortices inside the inner tube due to the Z-shaped structure, resulting in better circulation uniformity and preventing gel formation. The heat-insulating water in the outer tube extends into the Z-shaped structure, which insulates the center of the original liquid and reduces the temperature difference between the tube wall and the center.

3. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 2, characterized in that: Metal filter screens are arranged in an alternating pattern between the slanted Z-shaped structures of the inner tubes to filter out gels and impurities in the raw solution. The filter screens are disassembled and cleaned separately when cleaning the pipeline.

4. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 1, characterized in that, In the layered irregular jacketed raw liquid pipe (6), the raw liquid in the inner layer pipe and the heat-insulating water in the outer layer heat-insulating water flow line flow in opposite directions to maximize the heat exchange efficiency.

5. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 1, characterized in that, The thermal insulation water system includes a thermal insulation water storage tank (1), a thermal insulation water delivery pump (2), and a thermal insulation water heat exchanger (3). The thermal insulation water storage tank (1) is connected to the thermal insulation water delivery pump (2) through valves and pipelines. The thermal insulation water delivery pump (2) is connected to the thermal insulation water heat exchanger (3) through valves and pipelines. Both ends of the thermal insulation water system are connected to the outer thermal insulation water flow pipeline in the double-layer irregular jacketed raw liquid pipe (6) to form a thermal insulation water circulation.

6. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 1, characterized in that, Raw material delivery system: includes raw material storage tank (4) and raw material delivery pump (5); the raw material storage tank (4) is connected to the raw material delivery pump (5) through valves and pipelines, and the raw material delivery pump (5) is connected to the inner layer of the double-layer irregular jacketed raw material pipe (6) through valves and pipelines.

7. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 1, characterized in that, The iron removal filtration system includes an iron removal filter (7) and a raw liquid filter (8); the raw liquid filter (8) is connected to the iron removal filter (7) to filter impurities in the raw liquid.

8. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 1, characterized in that, The inner tube of the double-layer irregular jacketed raw liquid tube (6) is equipped with a temperature sensor and a pressure sensor at the raw liquid outflow end. These sensors are used to detect the temperature and pressure of the raw liquid in real time, and to judge the viscosity fluctuation trend of the material based on the changes in temperature and pressure values. This allows for timely adjustment of the temperature of the insulation water in the insulation water system, reducing material fluctuations and improving the stability of the raw silk production line.

9. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 1, characterized in that, The inner tube of the double-layer irregular jacketed raw liquid tube (6) is a combination of two semicircles. The semicircles are fixedly connected and the raw liquid flow lines of the two inner tubes are switched for backup, which is convenient for disassembly and cleaning.

10. The apparatus for constant-temperature uniform delivery of spinning solution according to claim 7, characterized in that, Before the raw liquid is delivered to the raw liquid filter (8), an additional iron removal filter (7) is added for backup.

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