A device for reducing the cost of water drawing of pan precursors

Abstract

This invention relates to a device for reducing the cost of water-drawing PAN raw fibers, solving the problem of high costs in existing water-washing and water-drawing processes. The device includes an insulated storage tank, a hot water transfer device, and an in-tank coil device. Drying condensate and demineralized water are mixed and sequentially passed through the PAN raw fiber water-drawing system, which consists of the insulated storage tank, the hot water transfer device, and the in-tank coil device, achieving temperature control during the water-drawing process. This invention's device for reducing the cost of water-drawing PAN raw fibers utilizes drying condensate and demineralized water, reducing water consumption during water-drawing, improving washing efficiency, and lowering production costs.

Description

Technical Field

[0001] This utility model belongs to the field of carbon fiber manufacturing technology, specifically relating to a device for reducing the cost of water-drawing PAN precursor fibers. Background Technology

[0002] Carbon fiber is a high-molecular-weight fiber material with a carbon content of over 90%. It possesses high strength, high modulus, acid and alkali resistance, and corrosion resistance, and is widely used in aerospace, transportation, and new energy fields, serving as a crucial material foundation for national economic development. High-strength, high-modulus carbon fiber has a tensile strength exceeding 7000 MPa and an elastic modulus exceeding 350 GPa, exhibiting extremely high stiffness, excellent specific modulus, and good environmental and dimensional stability. The production process of PAN carbon fiber involves polymerization, spinning, heat treatment, and carbonization. However, the production cost of the precursor fiber accounts for 50-60% of the total cost of carbon fiber. Reducing the waste of dimethyl sulfoxide (DMSO) solvent requires advanced water washing and water drawing processes to lower the DMSO content within the precursor fiber.

[0003] Traditional PAN raw yarn washing equipment employs a multi-stage, flow-controlled washing method. This involves injecting hot demineralized water into a water-drawing tank, utilizing potential energy to achieve automatic flow of the demineralized water. While simple and efficient, this method struggles to precisely control the water-drawing temperature and consumes a large amount of water, resulting in high costs. Current technologies utilize heat exchange devices, but these are also costly. Therefore, there is an urgent need for a device that reduces the cost of water-drawing. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a device for reducing the cost of water-drawing PAN raw yarn. This device maintains the temperature in the water-drawing tank by recycling the drying condensate, reducing the amount of flowing hot water and loss, improving the washing effect, and reducing production costs.

[0005] The technical solution to achieve the purpose of this utility model is as follows:

[0006] A device for reducing the cost of water-drawing PAN precursor fibers, the device

[0007] By utilizing the condensate from the drying process, the temperature inside the tank is maintained, reducing the amount of hot water flowing and its loss, improving the washing effect, and lowering production costs.

[0008] By reducing the number of heat exchange devices and maintaining the temperature in the water traction and washing tanks through the installation of coil structures within the tanks, the amount of hot water flowing and its loss are reduced, thereby improving the washing effect and lowering production costs.

[0009] The device includes:

[0010] Insulated storage tank equipment, hot water transmission equipment and in-tank coil equipment;

[0011] The insulated storage tank unit is connected to the coil unit inside the tank via a hot water transfer device;

[0012] The insulated storage tank, hot water transfer device, and in-tank coil device are all equipped with a two-stage structure.

[0013] In the first stage of the structure, the insulated storage tank device includes a flow meter, a pneumatic valve, a thermometer, a level gauge, an insulated storage tank, and a demineralized water pipeline.

[0014] The hot water transmission device includes a pressure gauge, a motor pump, and a pneumatic valve;

[0015] The in-tank coil device includes an in-tank coil and a temperature sensor; the in-tank coil is installed inside the water-pulling tank, and the temperature sensor is installed on the side wall of the water-pulling tank.

[0016] In the second-level structure, the insulated storage tank device includes a flow meter, a pneumatic valve, a thermometer, a level gauge, an insulated storage tank, and a demineralized water pipeline;

[0017] The hot water transmission device includes a pressure gauge, a motor pump, and a pneumatic valve;

[0018] The in-tank coil device includes an in-tank coil and a temperature sensor; the in-tank coil is installed inside the washing tank, and the temperature sensor is installed on the side wall of the washing tank.

[0019] The two-stage structure is connected by a pipe.

[0020] This device uses a PAN raw yarn water-pulling system, consisting of an insulated storage tank, a hot water delivery system, and an in-tank coil system, to sequentially pass the dried condensate and demineralized water (hereinafter referred to as hot demineralized water) through the in-tank coils. The hot demineralized water enters a two-stage water-pulling and washing system through the in-tank coils, and exits the multi-stage washing system from the final washing tank end. The hot demineralized water is then led from the outlet end of each stage of the water-pulling and washing device to the inlet end of the next stage of the demineralized water washing device.

[0021] In this invention, the inner coils of the water-lifting tank and the inner coils of the water-washing tank are provided with elliptical holes, with a length-to-diameter ratio of 2:1 to 2 and a length of 5 to 10 mm. The distance between the holes is 5 to 10 cm, and the hole size adopts a variable diameter design, with the diameter of the channel being smaller near the water inlet and gradually increasing as it moves away. This makes the pressure distribution of the water flow in the coil more uniform, thereby improving the uniformity of water intake. Designing the channels as elliptical can improve the outflow characteristics of the water flow, reduce eddies and turbulence at the channel outlet, and make the water flow into the tank more smoothly and evenly, reducing the risk of local blockage caused by uneven water flow.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] This invention provides a device for reducing the cost of water-drawing PAN raw yarn, realizing the recycling of drying condensate, reducing heat desalination water loss, improving washing efficiency, and reducing production costs. By setting a coil structure inside the tank, the pressure distribution of water flow within the coil is made more uniform, thereby improving the uniformity of water intake.

[0024] The coil structure of this utility model has an elliptical channel design, which improves the outflow characteristics of water, reduces eddies and turbulence at the channel outlet, and allows water to enter the water tank more smoothly and evenly, reducing the risk of local blockage caused by uneven water flow and further improving the uniformity of temperature space in the tank. Attached Figure Description

[0025] Figure 1 A schematic diagram of a device for reducing the cost of water-drawing PAN precursor fibers.

[0026] 1. Flow meter; 2. Pneumatic valve; 3. Thermometer; 4. Level gauge; 5. Insulated storage tank one; 6. Pressure gauge; 7. Pump; 8. Coil inside the water traction tank; 9. Temperature sensor; 10. Insulated storage tank two; 11. Coil inside the water washing tank; 12. Demineralized water pipeline. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0028] This utility model relates to a device for reducing the cost of water-drawing PAN raw fibers. The device includes:

[0029] Insulated storage tank equipment, hot water transmission equipment and in-tank coil equipment;

[0030] The insulated storage tank unit is connected to the coil unit inside the tank via a hot water transfer device;

[0031] The insulated storage tank, hot water transfer device, and in-tank coil device are all equipped with a two-stage structure.

[0032] In the first stage structure, the insulated storage tank device includes a flow meter 1, a pneumatic valve 2, a thermometer 3, a level gauge 4, an insulated storage tank 5, and a demineralized water pipeline 12.

[0033] The hot water transmission device includes a pressure gauge 6, a motor pump 7, and a pneumatic valve 2;

[0034] The in-tank coil device includes an in-tank coil 8 and a temperature sensor 9; the in-tank coil 8 is installed inside the water-pulling tank, and the temperature sensor 9 is installed on the side wall of the water-pulling tank.

[0035] In the second-level structure, the insulated storage tank device includes a flow meter 1, a pneumatic valve 2, a thermometer 3, a level gauge 4, an insulated storage tank 10, and a demineralized water pipeline 12.

[0036] The hot water transmission device includes a pressure gauge 6, a motor pump 7, and a pneumatic valve 2;

[0037] The in-tank coil device includes an in-tank coil 11 and a temperature sensor 9; the in-tank coil 11 is installed inside the washing tank, and the temperature sensor 9 is installed on the side wall of the washing tank.

[0038] The two-stage structure is connected by a pipe.

[0039] The present invention provides the following specific solution: In the insulated storage tank device in the first-stage structure and the second-stage structure, a flow meter, a pneumatic valve, a thermometer, and a level gauge are respectively installed on the insulated storage tank.

[0040] The present invention provides the following specific solution: In the first-stage structure and the second-stage structure, a pipeline is provided to inject the drying condensate into the first insulated storage tank 5 or the second insulated storage tank 10. The demineralized water pipeline 12 is connected to the first insulated storage tank 5 or the second insulated storage tank 10, which can mix the condensate and the demineralized water.

[0041] The present invention provides the following specific solution: the pressure gauge, motor pump and pneumatic valve in the hot water transmission device are respectively installed on the pipeline between the insulated storage tank device and the coil device in the tank.

[0042] The specific solution provided by this utility model is as follows: the water-pulling tank inner coil 8 and the water washing tank inner coil 11 of the inner coil device are both 316L stainless steel inner coils.

[0043] The specific solution provided by this utility model is as follows: the length of the inner coil 8 in the water traction tank and the inner coil 11 in the water washing tank is 15-20m; the flow rate is 900-1500L / h;

[0044] The present invention provides the following specific solution: elliptical holes are provided on the inner coil 8 of the water traction tank and the inner coil 11 of the water washing tank, with a length-to-diameter ratio of 2:1 to 2 and a length of 5 to 10 mm; the distance between the holes is 5 to 10 cm, and the hole size adopts a variable hole diameter design, with the hole diameter being smaller near the water inlet and gradually increasing as it moves away from the inlet.

[0045] When the device is in operation: It uses a PAN raw yarn water-pulling device, consisting of an insulated storage tank, a hot water delivery device, and an in-tank coil device, to sequentially pass the dried condensate and demineralized water (hereinafter referred to as hot demineralized water) through the in-tank coils. The hot demineralized water enters the two-stage water-pulling and washing system through the in-tank coils, and exits the multi-stage washing system from the final washing tank end. The hot demineralized water is then led from the outlet end of each stage of the water-pulling and washing device to the inlet end of the next stage of the demineralized water washing device.

[0046] The specific implementation parameters are as follows:

[0047] In the first stage structure, the flow rate of the drying condensate water is 800-900 L / h, and the condensate water temperature is 80-85℃; the flow rate of the demineralized water is 200-300 L / h, and the water temperature is 15-20℃.

[0048] In the second stage structure, the wash water in storage tank 210 is a mixture of water-drawing water and demineralized water.

[0049] The water flow rate is 700–800 L / h, and the temperature is 65–70℃. The desalinated water inlet flow rate is 1000–1500 L / h, and the water temperature is 15–20℃.

[0050] After the dried condensate and demineralized water are mixed, the temperature of the insulated storage tank 15 is controlled at 70-75℃; the temperature of the insulated storage tank 210 is controlled at 35-40℃.

[0051] Example

[0052] The temperature of the drying condensate is 82℃; the flow rate is 900L / h; the flow rate of the 15℃ demineralized water is 200L / h; and the water temperature inside the insulated storage tank is 70±1℃.

[0053] The inner coil is 15m long and has a flow rate of 1100L / h.

[0054] 900 L / h of overflow water from the water-drawing tank (reduced due to water being carried away by the fiber bundle) and 1500 L / h of demineralized water at 15°C are injected into the insulated storage tank 2 through pipelines;

[0055] The water at 40±1℃ inside the insulated storage tank exits the multi-stage washing system from the end of the final water washing tank.

Claims

1. A device for reducing the cost of water-drawing PAN raw fibers, characterized in that, The device includes: Insulated storage tank equipment, hot water transmission equipment and in-tank coil equipment; The insulated storage tank unit is connected to the coil unit inside the tank via a hot water transfer device; The insulated storage tank, hot water transfer device, and in-tank coil device are all equipped with a two-stage structure. In the first stage structure, the insulated storage tank device includes a flow meter (1), a pneumatic valve (2), a thermometer (3), a level gauge (4), an insulated storage tank (5), and a demineralized water pipeline (12). The hot water transmission device includes a pressure gauge (6), a motor pump (7), and a pneumatic valve (2); The in-tank coil device includes an in-tank coil (8) and a temperature sensor (9); the in-tank coil (8) is installed inside the water-pulling tank, and the temperature sensor (9) is installed on the side wall of the water-pulling tank. In the second-level structure, the insulated storage tank device includes a flow meter (1), a pneumatic valve (2), a thermometer (3), a level gauge (4), an insulated storage tank (10), and a demineralized water pipeline (12); The hot water transmission device includes a pressure gauge (6), a motor pump (7), and a pneumatic valve (2); The in-tank coil device includes an in-tank coil (11) and a temperature sensor (9); the in-tank coil (11) is installed inside the in-tank, and the temperature sensor (9) is installed on the side wall of the in-tank. The two-stage structure is connected by a pipe.

2. The apparatus for reducing the cost of water-drawing PAN raw fibers according to claim 1, characterized in that, Within the insulated storage tank devices of the first and second stage structures, flow meters, pneumatic valves, thermometers, and level gauges are respectively installed on the insulated storage tanks.

3. The apparatus for reducing the cost of water-drawing PAN raw fibers according to claim 2, characterized in that, In the first and second stage structures, pipes are installed to inject the drying condensate into the insulated storage tank (5). The demineralized water pipe (12) is connected to the insulated storage tank (5) to mix the condensate and demineralized water.

4. The apparatus for reducing the cost of water-drawing PAN raw fibers according to claim 1, characterized in that, The pressure gauge, motor pump, and pneumatic valve in the hot water transmission device are respectively installed on the pipeline between the insulated storage tank and the coil device inside the tank.

5. The apparatus for reducing the cost of water-drawing PAN raw fibers according to claim 1, characterized in that, The water-pulling tank inner coil (8) and the water washing tank inner coil (11) of the inner coil device are both 316L stainless steel inner coils.

6. The apparatus for reducing the cost of water-drawing PAN precursor fibers according to claim 1, characterized in that, The length of the coil (8) in the water traction tank and the coil (11) in the water washing tank is 15-20m; the flow rate is 900-1500L / h.

7. The apparatus for reducing the cost of water-drawing PAN raw fibers according to claim 1, characterized in that, Elliptical holes are provided on the inner coil (8) of the water traction tank and the inner coil (11) of the water washing tank. The length-to-diameter ratio is 2:1~2 and the length is 5~10mm. The distance between the holes is 5~10cm. The hole size adopts a variable hole diameter design. The diameter of the hole is small when it is close to the water inlet and gradually increases when it is far away.

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