Polyacrylonitrile-based carbon fiber polymerization raw material feeding system

Abstract

The invention discloses a polyacrylonitrile-based carbon fiber polymerization raw material feeding system, and belongs to the technical field of carbon fiber production equipment. Which comprises an IA preparation tank, an MA preparation tank and an AIBN preparation tank, and is characterized in that polymerization kettles are arranged on pipelines at the output ends of the IA preparation tank, the MA preparation tank and the AIBN preparation tank, and output liquids of the IA preparation tank, the MA preparation tank and the AIBN preparation tank are conveyed into the polymerization kettles; the automatic signal interlocking device is arranged according to key parameters, if technological parameters exceed an allowable range, before an accident is about to occur, a signal system automatically sends out an acousto-optic signal, an operator is warned to pay attention, measures are taken in time, and if the working condition reaches a dangerous state, the interlocking system immediately and automatically takes emergency measures, so that the safety of the accident is ensured. And an emergency cut-off valve is arranged, so that accidents are prevented from occurring and expanding.

Description

Technical Field

[0001] The patent of this invention belongs to the technical field of carbon fiber production equipment, and specifically relates to a feeding system for polyacrylonitrile-based carbon fiber polymer raw materials. Background Art

[0002] Polyacrylonitrile-based (PAN) carbon fiber accounts for 90% of the total carbon fiber production. The first polymerization monomer of PAN carbon fiber is acrylonitrile. Methyl acrylate and itaconic acid as comonomers can effectively improve the catalytic cyclization in the production process of PAN carbon fiber. Azobisisobutyronitrile as an initiator can effectively accelerate the reaction speed. Dimethyl sulfoxide is used as a solvent for synthesizing PAN copolymers. These five main raw materials contain a large amount of inorganic impurities, which have a great impact on the polymerization reaction itself and even the performance of the final product carbon fiber. They will break the regularity of the polymer chain, cause fiber pore defects, destroy the continuity of carbon fiber crystallization, and reduce the performance of carbon fiber. High-quality precursor with few defects is the premise for the preparation of high-performance carbon fiber. The development of high-purity and high-performance precursors and the reduction of congenital defects to a minimum have become the key to carbon fiber production. Therefore, the feeding system of the polymerization raw materials is very important for the industrial production of PAN-based carbon fiber.

[0003] At present, the raw material ratio in the production of polyacrylonitrile-based carbon fiber is not precise enough, which leads to differences in the production volume of each kettle and ultimately leads to unstable quality of carbon fiber precursor.

[0004] Invention patent content

[0005] The invention mainly solves the technical problems existing in the above-mentioned prior art and provides a feeding system for polyacrylonitrile-based carbon fiber polymerization raw materials.

[0006] The above technical problems of the present invention are mainly solved by the following technical solutions: a feeding system for polyacrylonitrile-based carbon fiber polymerization raw materials, including an IA preparation tank, an MA preparation tank and an AIBN preparation tank, characterized in that: the pipelines at the output ends of the IA preparation tank, the MA preparation tank and the AIBN preparation tank are all provided with polymerization kettles, and the output liquids of the IA preparation tank, the MA preparation tank and the AIBN preparation tank are all sent to the polymerization kettle, and the pipeline from the output end of the IA preparation tank to the input end of the polymerization kettle is sequentially provided with an IA preparation tank discharge valve, an IA first filter, an IA second filter, a FE1 mass flowmeter, an FE2 mass flowmeter, an FV1 regulating valve and an FV2 switch valve, the pipeline from the output end of the MA preparation tank to the input end of the polymerization kettle is sequentially provided with an MA preparation tank discharge valve, a MA first filter, an MA second filter, a FE3 mass flowmeter, a FE4 mass flowmeter, an FV3 regulating valve and an FV4 switch valve, and the AIB The pipeline from the output end of the N preparation tank to the input end of the polymerization kettle is sequentially provided with an AIBN preparation tank discharge valve, an AIBN first filter, an AIBN second filter, a FE5 mass flowmeter, an FE6 mass flowmeter, an FV5 regulating valve and an FV6 switch valve; the branch pipes of the liquid inlet pipeline of the polymerization kettle are respectively connected with an acrylonitrile liquid inlet pipe and a dimethyl sulfoxide liquid inlet pipe; the pipeline from the feed end to the input end of the polymerization kettle of the acrylonitrile liquid inlet pipe is sequentially provided with an AN pipeline feed valve, an FV7 regulating valve, a FV7 regulating valve sub-line valve, an AN first filter A, an AN second filter A, an FE7 mass flowmeter, an FE8 mass flowmeter and an FV9 switch valve; the pipeline from the feed end to the input end of the polymerization kettle of the dimethyl sulfoxide liquid inlet pipe is sequentially provided with a DMSO pipeline feed valve, an FV10 regulating valve, a DMSO first filter, a DMSO second filter, an FE9 mass flowmeter, an FE10 mass flowmeter, an FV11 regulating valve and an FV12 switch valve.

[0007] Preferably, the FV7 regulating valve is connected in parallel with a FV7 regulating valve secondary line valve via a pipeline.

[0008] Preferably, the AN first filter A is connected in parallel with an AN first filter B through a pipeline, the AN second filter A is connected in parallel with an AN second filter B through a pipeline, and the AN first filter B and the AN second filter B are interconnected through a pipeline.

[0009] Preferably, the FV10 regulating valve is connected in parallel with a FV10 regulating valve secondary line valve via a pipeline.

[0010] The patent of this invention has the following beneficial effects:

[0011] 1. The key parameters of the present invention are equipped with automatic signal interlocking devices. If the process parameters exceed the allowable range, before the accident is about to occur, the signal system will automatically send out sound and light signals to alert the operator and take timely measures. If the working condition has reached a dangerous state, the interlocking system will immediately and automatically take emergency measures and set an emergency shut-off valve to prevent the occurrence and expansion of the accident.

[0012] 2. The patented feeding method of the present invention adopts dual flow meters. The first flow meter is used as the on-site display and the DCS is remotely transmitted to accumulate the flow. It is calibrated with the second flow meter to ensure the measurement accuracy. At the same time, the second flow meter is interlocked with the regulating valve and the switch valve to control the feed amount. Once the accumulated amount reaches the high alarm, the interlock cuts off the cut-off valve.

[0013] 3. The raw materials are filtered twice before entering the polymerization reactor for reaction. The first one is coarse filtration and the second one is fine filtration to ensure that inorganic impurities are filtered out, dirt is reduced, and turbidity is reduced;

[0014] 4. The acrylonitrile feed pipeline is equipped with a regulating valve with the function of regulating and remote switching to prevent the pressure of opening the regulating valve from being too high. Open the secondary line valve first, and the secondary line can also participate in regulating and controlling the flow. At the same time, the dimethyl sulfoxide feed pipeline is equipped with a regulating valve with the function of regulating and remote switching to prevent the pressure of opening the regulating valve from being too high. Open the secondary line valve first, and the secondary line can also participate in regulating and controlling the flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of equipment installation of the patent of this invention.

[0016] In the figure: 1, IA preparation tank; 2, MA preparation tank; 3, AIBN preparation tank; 4, polymerization kettle; 5, IA preparation tank discharge valve; 6, IA first filter; 7, IA second filter; 8, FE1 mass flowmeter; 9, FE2 mass flowmeter; 10, FV1 regulating valve; 11, FV2 switch valve; 12, MA preparation tank discharge valve; 13, MA first filter; 14, MA second filter; 15, FE3 mass flowmeter; 16, FE4 mass flowmeter; 17, FV3 regulating valve; 18, FV4 switch valve; 19, AIBN preparation tank discharge valve; 20, AIBN first filter; 21, AIBN second filter; 22, FE5 mass flowmeter; 23, FE6 mass flowmeter; 24, F V5 regulating valve; 25, FV6 switching valve; 26, AN pipeline feed valve; 27, FV7 regulating valve; 28, FV7 regulating valve bypass valve; 29, AN first filter A; 30, AN first filter B; 31, AN second filter A; 32, AN second filter B; 33, FE7 mass flowmeter; 34, FE8 mass flowmeter; 35, FV8 regulating valve; 36, FV9 switching valve; 37, DMSO pipeline feed valve; 38, FV10 regulating valve; 39, FV10 regulating valve bypass valve; 40, DMSO first filter; 41, DMSO second filter; 42, FE9 mass flowmeter; 43, FE10 mass flowmeter; 44, FV11 regulating valve; 45, FV12 switching valve. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described in detail below through embodiments and in combination with the accompanying drawings.

[0018] Embodiment: A feeding system for polyacrylonitrile-based carbon fiber polymer raw material, such as Figure 1 As shown, it includes an IA preparation tank 1, an MA preparation tank 2 and an AIBN preparation tank 3. The pipelines at the output ends of the IA preparation tank 1, the MA preparation tank 2 and the AIBN preparation tank 3 are all provided with a polymerization kettle 4. The output liquids of the IA preparation tank 1, the MA preparation tank 2 and the AIBN preparation tank 3 are all sent to the polymerization kettle 4. The output liquids of the IA preparation tank 1, the MA preparation tank 2 and the AIBN preparation tank 3 are all sent to the polymerization kettle 4. The raw materials inside the IA preparation tank 1 are Itaconic acid, the internal temperature is controlled at 25 ° C, the internal pressure is 0.005 MPa (G), the IA preparation tank 1 is connected to the IA preparation tank discharge valve 5 on the pipeline from the output end to the input end of the polymerization kettle 4, and then the itaconic acid raw material is filtered through the IA first filter 6 and the IA second filter 7. The filtration accuracy of the IA first filter 6 is 0.8-1 μm, the filtration accuracy of the IA second filter 7 is 0.4-0.6 μm, and the flow rate of the two is 2.5-3.0 m 3 / h, the filtered itaconic acid raw material is sent to FE1 mass flowmeter 8, and then sent to FE2 mass flowmeter 9 through FE1 mass flowmeter 8. FE1 mass flowmeter 8 and FE2 mass flowmeter 9 are mutually calibrated and connected in series to reduce errors. The control requires DCS to provide instantaneous display and remote accumulation. In the pipeline on the rear side of FE2 mass flowmeter, FV1 regulating valve 10 is installed. The rear side of FV1 regulating valve 10 is connected with FV2 switch valve 11 in the front section pipeline entering polymerization kettle 4, and the flow rate is 2.5~3.0m 3 / h, temperature is 25℃, pressure is 0.6MPa (G), closing pressure difference is 0.05MPa, interlocking flow regulation, if the accumulated value shows high liquid level alarm interlocking cuts off FV2 switch valve 11.

[0019] The raw material inside the MA preparation tank 2 is methyl acrylate, the internal temperature is controlled at 25°C, and the internal pressure is 0.005MPa(G). The MA preparation tank 2 is connected to the MA preparation tank discharge valve 12 on the pipeline from the output end to the input end of the polymerization kettle 4. Then the methyl acrylate raw material is filtered through the MA first filter 13 and the MA second filter 14. The filtration accuracy of the MA first filter 13 is 0.8-1μm, and the filtration accuracy of the MA second filter 14 is 0.4-0.6μm. The flow rate of the two is 3.3-4.0m 3 / h, the temperature is 40℃, the filtered methyl acrylate raw material is sent to FE3 mass flowmeter 15, and then sent to FE4 mass flowmeter 16 through FE3 mass flowmeter 15, FE3 mass flowmeter 15 and FE4 mass flowmeter 16 are mutually calibrated, and the error is reduced by series connection. The control requires DCS, which provides instantaneous display and remote accumulation. FV3 regulating valve 17 is set in the pipeline on the rear side of FE4 mass flowmeter 16, and FV4 switch valve 18 is connected to the rear side of FV3 regulating valve 17 in the front section pipeline entering polymerization kettle 4, and the flow rate is 3.3~4.0m 3 / h, temperature is 40℃, pressure is 0.6MPa (G), closing pressure difference is 0.05MPa, interlocking flow regulation, if the accumulated value shows high liquid level alarm interlocking cuts off FV4 switch valve 18.

[0020] The raw material inside the AIBN preparation tank 3 is azobisisobutyronitrile, the internal temperature is controlled at 25°C, and the internal pressure is 0.005MPa(G). The AIBN preparation tank 3 is connected to the AIBN preparation tank discharge valve 19 on the pipeline from the output end to the input end of the polymerization kettle 4. Then the azobisisobutyronitrile raw material is filtered through the AIBN first filter 20 and the AIBN second filter 21. The filtration accuracy of the AIBN first filter 20 is 0.8-1μm, and the filtration accuracy of the AIBN second filter 21 is 0.4-0.6μm. The flow rate of the two is 1.7-2.0m 3 / h, the temperature is 25℃, the filtered azobisisobutyronitrile raw material is sent to FE3 mass flowmeter 15, and then sent to FE6 mass flowmeter 23 through FE5 mass flowmeter 22. FE5 mass flowmeter 22 and FE6 mass flowmeter 23 are mutually calibrated and connected in series to reduce errors. The control requires DCS to provide instantaneous display and remote accumulation. FV5 regulating valve 24 is set in the pipeline on the rear side of FE6 mass flowmeter 23. FV6 switch valve 25 is connected to the rear side of FV5 regulating valve 24 in the front section pipeline entering polymerization kettle 4, and the flow rate is 1.7~2.0m 3 / h, temperature is 25℃, pressure is 0.6MPa(G), closing pressure difference is 0.05MPa, interlocking flow adjustment, if the accumulated value shows high liquid level alarm, interlocking cuts off FV6 switch valve 25

[0021] The pipelines at the output ends of the IA preparation tank 1, the MA preparation tank 2 and the AIBN preparation tank 3 are all output to the feed pipe of the polymerization kettle 4. The feed pipe of the polymerization kettle 4 is also connected with an acrylonitrile inlet pipe and a dimethyl sulfoxide inlet pipe. The input end of the acrylonitrile inlet pipe is connected to the acrylonitrile raw material kettle, and the feed end of the pipeline is provided with an AN pipeline feed valve 26 to control the feed of acrylonitrile. When feeding is required, the FV7 regulating valve secondary line valve 28 is opened first, and then the FV7 regulating valve 27 is opened again. The FV7 regulating valve 27 also has a remote control function, and the flow of the AN feed pipeline can be remotely closed. The pipeline flow rate at this location is 15-20m 3 / h, the temperature is 25℃, the pressure is 0.6MPa(G), the closing pressure difference is 0.05MPa, to prevent the pressure from being too high when opening the FV7 regulating valve 27, first open the FV7 regulating valve secondary line valve 28, and at the same time, the secondary pipeline of the FV7 regulating valve secondary line valve 28 connected in parallel with the FV7 regulating valve 27 can also participate in regulating the flow rate, and then the acrylonitrile raw material is sent to the AN first filter A29, whose filtration accuracy is 0.8~1μm, and then flows to the AN second filter A31 again, whose filtration accuracy is 0.4~0.6μm, and the flow rate is 15~20m 3 / h, the temperature is 25℃, the pressure is 0.6MPa(G), and at the same time, the AN first filter B30 is connected in parallel to the AN first filter A29, and the AN second filter B32 is connected in parallel to the AN second filter A31, and the AN first filter B30 and AN second filter B32 pipelines are also interconnected. Since AN is a highly hazardous medium, spare filters are set to prevent emergencies. Then the acrylonitrile raw material passes through the FE7 mass flow meter 33 on the pipeline backward, and the flow rate is 15-20m 3 / h, the temperature is 25℃, the pressure is 0.6MPa(G), the control requires DCS, provides instantaneous display, remote accumulation, and then the acrylonitrile raw material passes through the FE8 mass flow meter 34 on the pipeline, the FE7 mass flow meter 33 and the FE8 mass flow meter 34 are calibrated with each other, and the series flow meters are connected to reduce the error and then sent to the polymerization kettle 4 through the FV8 regulating valve 35 and the FV9 switch valve 36. The FV8 regulating valve 35 is closed with a pressure difference of 0.05Mpa, and the interlock is used to adjust the flow rate. Finally, if the accumulated value of the acrylonitrile raw material shows a high liquid level alarm, the FV9 switch valve 36 is interlocked to close the pipeline for sending the acrylonitrile raw material to the polymerization kettle 4.

[0022] The input end of the dimethyl sulfoxide inlet pipe is connected to the raw material kettle of dimethyl sulfoxide, and the feeding end of the pipeline is provided with a DMSO pipeline feeding valve 37 to control the feeding of dimethyl sulfoxide. When feeding is required, the FV10 regulating valve secondary line valve 39 is opened first, and then the FV10 regulating valve 38 is opened again. The FV10 regulating valve 38 also has a remote control function, which can remotely close the flow of the DMSO feeding pipeline. The pipeline flow rate at this location is 25-30m 3 / h, the temperature is 50℃, the pressure is 0.6MPa(G), the closing pressure difference is 0.05MPa, to prevent the pressure from being too high when opening the FV10 regulating valve 38, first open the FV10 regulating valve secondary line valve 39, and at the same time, the secondary pipeline of the FV10 regulating valve secondary line valve 39 connected in parallel with the FV10 regulating valve 38 can also participate in regulating the flow rate, and then the dimethyl sulfoxide raw material is sent to the DMSO first filter 40, whose filtration accuracy is 0.8~1μm, and then flows to the DMSO second filter 41 again, whose filtration accuracy is 0.4~0.6μm, and the flow rate is 30~40m 3 / h,, the temperature is 50℃, the pressure is 0.6MPa(G), and then the dimethyl sulfoxide raw material passes through the FE9 mass flow meter 42 on the pipeline, with a flow rate of 30~40m 3 / h, the temperature is 50℃, the pressure is 0.6MPa(G), the control requires DCS, provides instantaneous display, remote accumulation, and then the dimethyl sulfoxide raw material passes through the FE10 mass flowmeter 43 on the pipeline, the FE9 mass flowmeter 42 and the FE10 mass flowmeter 43 are calibrated with each other, and the series flowmeters reduce the error and are sent to the polymerization kettle 4 through the FV11 regulating valve 44 and the FV12 switch valve 45. The FV11 regulating valve 44 is closed with a pressure difference of 0.05Mpa, and the interlock is used to adjust the flow rate. Finally, if the accumulated value of the dimethyl sulfoxide raw material shows a high liquid level alarm, the interlock cuts off the FV12 switch valve 45 to close the pipeline for sending the dimethyl sulfoxide raw material to the polymerization kettle 4.

[0023] Finally, all the raw materials are sent to the polymerization kettle through the feeding pipe of the polymerization kettle for polymerization reaction.

[0024] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention should be considered to fall within the protection scope of the present invention.

Claims

1. A feeding system for polyacrylonitrile-based carbon fiber polymer raw materials, comprising an IA preparation tank (1), an MA preparation tank (2) and an AIBN preparation tank (3), characterized in that: A polymerization kettle (4) is arranged on the pipelines at the output ends of the IA preparation tank (1), the MA preparation tank (2) and the AIBN preparation tank (3); the output liquids of the IA preparation tank (1), the MA preparation tank (2) and the AIBN preparation tank (3) are all sent to the polymerization kettle (4); and an IA preparation tank discharge valve (5), an IA first filter (6), an IA second filter (7), an FE1 mass flow meter (8), an FE2 mass flow meter (9) are arranged in sequence on the pipeline from the output end of the IA preparation tank (1) to the input end of the polymerization kettle (4). ), FV1 regulating valve (10) and FV2 switch valve (11); the pipeline from the output end of the MA preparation tank (2) to the input end of the polymerization kettle (4) is provided with an MA preparation tank discharge valve (12), a MA first filter (13), an MA second filter (14), an FE3 mass flow meter (15), an FE4 mass flow meter (16), an FV3 regulating valve (17) and an FV4 switch valve (18); the pipeline from the output end of the AIBN preparation tank (3) to the input end of the polymerization kettle (4) is provided with an AIBN preparation tank discharge valve ( 19), AIBN first filter (20), AIBN second filter (21), FE5 mass flow meter (22), FE6 mass flow meter (23), FV5 regulating valve (24) and FV6 switch valve (25); the branch pipes of the liquid inlet pipeline of the polymerization kettle (4) are respectively connected to an acrylonitrile liquid inlet pipe and a dimethyl sulfoxide liquid inlet pipe; the pipeline of the acrylonitrile liquid inlet pipe from the feed end to the input end of the polymerization kettle (4) is sequentially provided with an AN pipeline feed valve (26), an FV7 regulating valve (27), an AN first filter A (29), an AN A second filter A (31), a FE7 mass flowmeter (33), a FE8 mass flowmeter (34) and a FV9 switch valve (36); a DMSO pipeline feed valve (37), a FV10 regulating valve (38), a DMSO first filter (40), a DMSO second filter (41), a FE9 mass flowmeter (42), a FE10 mass flowmeter (43), a FV11 regulating valve (44) and a FV12 switch valve (45) are sequentially arranged on the dimethyl sulfoxide inlet pipe from the feed end to the input end of the polymerization kettle (4).

2. The feeding system of a polyacrylonitrile-based carbon fiber polymer raw material according to claim 1, characterized in that: The FV7 regulating valve (27) is connected in parallel with an FV7 regulating valve secondary line valve (28) via a pipeline.

3. The feeding system of a polyacrylonitrile-based carbon fiber polymer raw material according to claim 1, characterized in that: The AN first filter A (29) is connected in parallel with an AN first filter B (30) through a pipeline, and the AN second filter A (31) is connected in parallel with an AN second filter B (32) through a pipeline. The AN first filter B (30) and the AN second filter B (32) are interconnected through a pipeline.

4. The feeding system of a polyacrylonitrile-based carbon fiber polymer raw material according to claim 1, characterized in that: The FV10 regulating valve (38) is connected in parallel with an FV10 regulating valve secondary line valve (39) via a pipeline.

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