Carbon fiber pre-oxidation device

Abstract

The invention relates to the technical field of carbon fiber production, in particular to a carbon fiber pre-oxidation device which comprises a pre-oxidation box and a control module, the pre-oxidation box is divided into three pre-oxidation areas through four heat insulation plates in the pre-oxidation box, and through grooves are formed in the middle positions of the side faces of the heat insulation plates; a tension isolation buffering assembly and a material guiding assembly are fixedly installed on the heat insulation plate. A tension adjusting assembly is fixedly mounted in the middle of the bottom of the pre-oxidation area; a heater and an oxygen introduction assembly are mounted in the oxidation zone; through collaborative design of the tension isolation buffering assembly, the material guiding assembly, the tension adjusting assembly and the control module, the problem of carbon fiber tension mismatch at the gradient temperature in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of carbon fiber production, in particular to a carbon fiber pre-oxidation device. Background Art

[0002] The carbon fiber pre-oxidation furnace is a core piece of equipment in the carbon fiber production process, primarily used to pre-oxidize polyacrylonitrile (PAN) precursor. During this process, the PAN fibers undergo chemical cross-linking under a controlled temperature and oxidizing atmosphere, forming a thermally stable trapezoidal structure. This paves the way for subsequent high-temperature carbonization and prevents fiber melting or deformation.

[0003] There is a patent in the prior art with application number CN202411001726.7 that provides a carbon fiber pre-oxidation processing device, including a base, with support legs fixedly installed at the four corners of the top of the base, an oxidation box fixedly installed on the top of the support legs, a tensioning mechanism provided in the oxidation box, and an oxygen supply mechanism fixedly installed inside the oxidation box. The heater assemblies at the top and bottom of the oxidation box uniformly heat the carbon fiber through electric heating wires, and the tensioning force of the carbon fiber can be flexibly adjusted through the setting of the tensioning mechanism.

[0004] However, the pre-oxidation processing device provided by the above patent still has the following deficiencies during use: According to its content, the oxidation box is equipped with multiple sets of tensioning mechanisms, and is equipped with adjustment components to synchronously control the multiple sets of tensioning mechanisms. In the actual carbon fiber oxidation process, the carbon fiber is usually heated and oxidized at a gradient temperature. The synchronous adjustment of the multiple sets of tensioning mechanisms in the above patent results in the carbon fiber being subjected to the same tension at different temperatures, which is mismatched with the gradient temperature. In the low-temperature stage, the fiber undergoes a violent cyclization reaction, with a shrinkage rate of up to 10% to 15%. If the tension is insufficient, the shrinkage cannot be effectively suppressed. In the high-temperature stage, the fiber has formed a rigid trapezoidal structure, and the toughness has dropped significantly. At this time, applying the same high tension as in the low-temperature zone will expand the surface defects of the fiber, resulting in a decrease in tensile strength and even broken wires. Summary of the Invention

[0005] The object of the present invention is to provide a carbon fiber pre-oxidation device to solve the problems raised in the above background technology.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A carbon fiber preoxidation device includes a preoxidation box and a control module. The preoxidation box includes a top plate. Side panels 1 and 2 are fixedly mounted on both sides of the top surface of the preoxidation box, and the top plate is fixedly mounted between the top surfaces of the side panels 1 and 2. A heat insulation plate is provided between both ends of the side panels 1 and 2, and two of the heat insulation plates are installed in the preoxidation box at intervals. The four heat insulation plates divide the preoxidation box into three preoxidation zones. Temperature sensors and oxygen concentration sensors are installed in the preoxidation zones. A through groove is provided in the middle of the side of the heat insulation board, and tension isolation and buffer components are fixedly installed on the inner side surfaces of the two heat insulation boards at both ends. The tension isolation and buffer components are fixedly installed on both sides of the two middle heat insulation boards, and material guide components are fixedly installed on both sides of the four heat insulation boards; A tension adjustment component is fixedly installed at the middle position of the bottom of the pre-oxidation zone; A heater and an oxygen introduction component are installed in the oxidation zone; The control module is electrically connected to the temperature sensor, the oxygen concentration sensor, the tension adjustment component, the oxygen supply pipe and the tension isolation buffer component.

[0007] Furthermore, the material guide assembly includes two convex plates fixedly mounted on the side surfaces of the heat insulation plate, and the two convex plates are respectively located at the two ends of the through groove; Two guide rollers three are rotatably mounted between the two convex plates, and the interval between the two guide rollers three is aligned with the through slot.

[0008] Furthermore, the tension isolation buffer assembly includes a mounting plate vertically fixedly mounted on the side of the heat insulation board, the mounting plate is located below the through slot, the top surface of the mounting plate is provided with movable slots near both ends, and vertical plates are fixedly mounted at both ends of the top surface of the mounting plate, and the vertical plates are aligned with the middle position of the movable slots; A buffer assembly is provided on the inner side of the vertical plate near the top, and a guide roller is rotatably installed between two groups of the buffer assemblies; An angle adjustment component used in conjunction with the guide roller 1 is also fixedly mounted on the mounting plate.

[0009] Furthermore, the wrap angle adjustment assembly includes two guide rollers three fixedly mounted on the bottom surface of the mounting plate, a slide rod is fixedly connected between the two guide rollers three, and a bidirectional screw rod is rotatably mounted between the two guide rollers three; A motor is fixedly mounted on the outer surface of the guide roller three away from the heat insulation plate, and the motor is electrically connected to the control module. The end of the bidirectional screw rod close to the motor rotates through the guide roller three at the corresponding position and is fixedly connected to the output shaft end of the motor; The outer periphery of the bidirectional screw rod is threadedly mounted with two mounting strips symmetrically distributed about the guide roller, and the mounting strips are in sliding connection with the slide rod; Mounting seats are fixedly installed at both ends of the top surface of the mounting strip, and the top ends of the mounting seats pass through the movable slots at corresponding positions to the top of the mounting plate. Guide roller 2 is rotatably installed on the opposite sides of the two mounting seats near the top position.

[0010] Furthermore, the buffer assembly includes a mounting groove formed on the inner side of the vertical plate, a spring damper is fixedly mounted on the bottom of the mounting groove, and a slider is fixedly mounted on the top of the spring damper and is in sliding contact with the inner wall of the mounting groove; One end of the guide roller close to the vertical plate is rotatably connected to the side surface of the sliding block.

[0011] Furthermore, the tension adjustment assembly includes an electric push rod fixedly mounted on the top surface of the top plate, a U-shaped mounting seat fixedly mounted on the top end of the electric push rod, and a tension sensor is provided between the U-shaped mounting seat and the electric push rod, and the tension sensor and the electric push rod are both electrically connected to the control module; Telescopic rods are fixedly installed between the two ends of the bottom surface of the U-shaped mounting seat and the top surface of the top plate; A tension roller is rotatably mounted between the two ends of the U-shaped mounting seat.

[0012] Furthermore, an exhaust cavity is provided in the top plate, and a plurality of through holes are provided on the inner bottom surface of the exhaust cavity above the pre-oxidation zone; An exhaust pipe that passes through the exhaust cavity is fixedly mounted on one end of the top plate close to the downstream, and an end of the exhaust pipe away from the top plate is connected to an external purification exhaust system.

[0013] Furthermore, three transition cavities are arranged in an array along the length direction of the top plate and are respectively located directly above the three pre-oxidation zones, and the transition cavities are located above the exhaust cavity; Three oxygen supply pipes are fixedly installed on one side of the top plate close to the side plate 1, which are connected to the three transition cavities respectively. The oxygen supply pipes are provided with flow valves. The ends of the oxygen supply pipes away from the top plate are connected to an external oxygen supply device. Three air guide tubes are fixedly installed on one side of the top plate close to the second side plate, respectively penetrating the three transition cavities. One end of the air guide tube away from the top plate passes through the second side plate near the lower part of the second side plate to the corresponding pre-oxidation zone and is then connected to the oxygen introduction assembly. A plurality of array-distributed baffles are fixedly connected to both ends of the transition cavity along its length direction. The top end of the baffle is fixedly connected to the top surface of the transition cavity, and the bottom end of the baffle is fixedly connected to the bottom surface of the transition cavity. The baffle is parallel to the length direction of the transition cavity, and the length of the baffle is less than the length of the transition cavity. The multiple baffles at both ends of the transition cavity are staggered to form an S-shaped oxygen channel in the transition cavity.

[0014] Furthermore, the oxygen introduction assembly includes an oxygen supply pipe fixedly installed in the oxidation zone, one end of the oxygen supply pipe is closed, and the other end is fixedly connected to the end of the air guide pipe away from the top plate; The periphery of the oxygen supply tube is provided with a plurality of air outlets in an array along the length direction thereof.

[0015] Furthermore, three box doors corresponding to the three pre-oxidation zones are installed on the side surface of the side panel 1.

[0016] Beneficial effects of the present invention: 1. The present invention solves the problem of carbon fiber tension mismatch under gradient temperature in the prior art through the collaboration of tension isolation and buffer components, material guide components and control modules. Specifically, the physical mechanism of wrap angle adjustment and buffer isolation, combined with real-time feedback control, enables the precise realization of tension gradient.

[0017] 2. The tension isolation and buffer assembly's guide rollers 1 and 2, as well as the wrap angle adjustment assembly, work in conjunction with the control module to independently adjust the tension in the three pre-oxidation zones. Furthermore, the spring damper and slider design absorb certain tension fluctuations to prevent wire breakage.

[0018] 3. In the present invention, oxygen enters the transition cavity through an oxygen supply tube, where it flows for a longer time in the S-shaped path formed by interlaced baffles, preheating the oxygen using the high-temperature exhaust gas in the exhaust cavity. After preheating, the oxygen enters the oxygen supply tube through an air duct and is evenly sprayed into the pre-oxidation zone through multiple outlets, ensuring uniform oxidation reaction. Simultaneously, the reaction waste gas enters the exhaust cavity through a through-hole and is directed to the purification system via an exhaust pipe, preventing the accumulation of harmful gases such as HCN. The S-shaped channel design of the transition cavity significantly improves oxygen preheating efficiency, thereby reducing external heating energy consumption and improving resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, those skilled in the art can derive other drawings based on these drawings without inventive effort. Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 A three-dimensional diagram from another angle; Figure 3 It is a three-dimensional schematic diagram of the internal structure of the pre-oxidation box in the present invention; Figure 4 is a three-dimensional schematic diagram of the oxidation zone in the present invention; Figure 5 It is a three-dimensional schematic diagram of the installation relationship between the tension buffer component and the material guide component and the heat insulation board in the present invention; Figure 6 yes Figure 5 Enlarged view of part A; Figure 7 yes Figure 5 A three-dimensional diagram from another angle; Figure 8 yes Figure 7 Enlarged view of part B; Figure 9 yes Figure 5 A three-dimensional schematic diagram from another angle; Figure 10 yes Figure 9 Enlarged view of part C; Figure 11 is a three-dimensional schematic diagram of the tension adjustment assembly of the present invention; Figure 12 This is a three-dimensional schematic diagram of the interior of the top plate in the present invention. Figure 1 ; Figure 13 This is a three-dimensional schematic diagram of the internal structure of the top plate in the present invention. Figure 2 ; The reference numerals in the figures are as follows: 1-pre-oxidation box, 2-box door, 3-oxygen supply pipe, 4-flow valve, 5-exhaust pipe, 6-heat insulation board, 7-air guide pipe, 8-top plate, 9-side panel 1, 10-side panel 2, 11-top plate, 12-oxygen supply pipe, 13-air outlet, 14-tension adjustment assembly, 15-material guide assembly, 16-tension isolation buffer assembly, 17-mounting plate, 18-vertical plate, 19-guide roller 1, 20-guide roller 2, 21-mounting seat, 22- Movable slot, 23-motor, 24-convex plate, 25-guide roller three, 26-slide rod, 27-bidirectional screw, 28-mounting strip, 29-spring damper, 30-slider, 31-telescopic rod, 32-electric push rod, 33-U-shaped mounting seat, 34-tension roller, 35-tension sensor, 36-transition cavity, 37-baffle, 38-exhaust cavity, 39-through hole, 40-mounting slot, 41-through slot, 42-heater. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] Example 1:

[0022] See also Figures 1 to 11 In an embodiment of the present invention, a carbon fiber preoxidation device includes a preoxidation box 1 and a control module. The preoxidation box 1 includes a top plate 11. Side panels 1 9 and 2 10 are fixedly mounted on both sides of the top surface of the preoxidation box 1. A top plate 8 is fixedly mounted between the top surfaces of the side panels 1 9 and 2 10. The device is characterized in that a heat insulation plate 6 is provided between both ends of the side panels 1 9 and 2 10, and two heat insulation plates 6 are installed in the preoxidation box 1 at intervals. The four heat insulation plates 6 divide the preoxidation box 1 into three preoxidation zones. Temperature sensors and oxygen concentration sensors are installed in the preoxidation zones. A through slot 41 is provided in the middle of the side of the heat insulation board 6. Tension isolation and buffer assemblies 16 are fixedly mounted on the inner side surfaces of the two heat insulation boards 6 at both ends. Tension isolation and buffer assemblies 16 are fixedly mounted on both sides of the two middle heat insulation boards 6. Material guide assemblies 15 are fixedly mounted on both sides of the four heat insulation boards 6. A tension adjustment assembly 14 is fixedly installed at the middle position of the bottom of the pre-oxidation zone; A heater 42 and an oxygen introduction assembly are installed in the oxidation zone; The control module is electrically connected to the temperature sensor, the oxygen concentration sensor, the tension adjustment assembly 14 , the oxygen supply tube 12 , and the tension isolation buffer assembly 16 .

[0023] The material guide assembly 15 includes two convex plates 24 fixedly mounted on the side of the heat insulation plate 6. The two convex plates 24 are respectively located at the two ends of the through slot 41. Two guide rollers 3 25 are rotatably mounted between the two convex plates 24 , and the interval between the two guide rollers 3 25 is aligned with the through slot 41 .

[0024] The tension isolation buffer assembly 16 includes a mounting plate 17 vertically fixedly mounted on the side of the heat insulation board 6. The mounting plate 17 is located below the through slot 41. The top surface of the mounting plate 17 is provided with movable slots 22 near both ends. Vertical plates 18 are fixedly mounted at both ends of the top surface of the mounting plate 17. The vertical plates 18 are aligned with the middle position of the movable slots 22. A buffer assembly is provided on the inner side of the vertical plate 18 near the top, and a guide roller 19 is rotatably installed between the two groups of buffer assemblies; An angle adjustment component used in conjunction with guide roller 19 is also fixedly mounted on the mounting plate 17.

[0025] The wrap angle adjustment assembly includes two guide rollers 25 fixedly mounted on the bottom surface of the mounting plate 17, a slide rod 26 is fixedly connected between the two guide rollers 25, and a bidirectional screw rod 27 is rotatably mounted between the two guide rollers 25; A motor 23 is fixedly mounted on the outer surface of the guide roller 3 25 away from the heat insulation plate 6. The motor 23 is electrically connected to the control module. The end of the bidirectional screw 27 close to the motor 23 rotates through the guide roller 3 25 at the corresponding position and is fixedly connected to the output shaft end of the motor 23. The outer periphery of the bidirectional screw rod 27 is threadedly mounted with two mounting strips 28 symmetrically distributed about the guide roller 19, and the mounting strips 28 are in sliding connection with the slide rod 26; Mounting seats 21 are fixedly installed at both ends of the top surface of the mounting strip 28. The top of the mounting seat 21 passes through the movable slot 22 at the corresponding position to the top of the mounting plate 17. Guide roller 20 is rotatably installed on the opposite sides of the two mounting seats 21 near the top position.

[0026] The buffer assembly includes a mounting groove 40 formed on the inner side of the vertical plate 18. A spring damper 29 is fixedly mounted on the bottom of the mounting groove 40. A slider 30 is fixedly mounted on the top of the spring damper 29 and is in sliding contact with the inner wall of the mounting groove 40. One end of the guide roller 19 close to the vertical plate 18 is rotatably connected to the side of the slider 30.

[0027] The tension adjustment assembly 14 includes an electric push rod 32 fixedly mounted on the top surface of the top plate 11. A U-shaped mounting seat 33 is fixedly mounted on the top of the electric push rod 32. A tension sensor 35 is provided between the U-shaped mounting seat 33 and the electric push rod 32. The tension sensor 35 and the electric push rod 32 are both electrically connected to the control module. Telescopic rods 31 are fixedly installed between the bottom ends of the U-shaped mounting base 33 and the top surface of the top plate 11; A tension roller 34 is rotatably mounted between the two ends of the U-shaped mounting seat 33 .

[0028] The top plate 8 is provided with an exhaust cavity 38, and a plurality of through holes 39 are provided on the inner bottom surface of the exhaust cavity 38 above the pre-oxidation zone. An exhaust pipe 5 that passes through the exhaust chamber 38 is fixedly mounted on one end of the top plate 8 close to the downstream, and an end of the exhaust pipe 5 away from the top plate 8 is connected to an external purified exhaust system.

[0029] A plurality of gas outlets 13 are arranged in an array along the length of the oxygen supply tube 12 .

[0030] When the present invention is used: Carbon fibers enter the pre-oxidation box 1 from the entrance and sequentially pass through three pre-oxidation zones separated by thermal insulation panels 6. In each pre-oxidation zone, the fibers pass over guide roller 3 25 of the material guide assembly 15 and guide rollers 1 19 and 20 of the tension isolation and buffer assembly 16 before being pulled out by a winding device at the end of the process.

[0031] 1. Temperature gradient setting: Each pre-oxidation zone is independently temperature-controlled, and the three pre-oxidation zones from left to right correspond to the low-temperature zone, medium-temperature zone and high-temperature zone respectively; the low-temperature zone has a greater tension on the carbon fiber to inhibit shrinkage, and the high-temperature zone needs to reduce the tension to prevent brittle fracture.

[0032] The temperature sensor feeds back data to the control module to adjust the power of the heater 42.

[0033] 2. Tension gradient adjustment to adapt to temperature gradient in different pre-oxidation zones: The motor 23 of the wrap angle adjustment assembly drives the bidirectional screw 27 to drive the two mounting strips 28 to slide closer or away, driving the two guide rollers 20 to move closer or away, thereby changing the contact wrap angle θ between the fiber and the guide roller 19; according to the Coulomb friction model T out =T in *e μθ , in the high temperature zone, the wrap angle θ is reduced and the tension increase is reduced.

[0034] The spring damper 29 in the buffer assembly absorbs sudden changes in tension, and the slider 30 on the vertical plate 18 slides to compensate for changes in fiber length, thereby isolating tension interference in adjacent temperature zones.

[0035] In the tension adjustment assembly, tension sensors 35 monitor the carbon fiber tension in the corresponding temperature zones in real time. The control module adjusts the electric push rod 32 to raise and lower the tension roller 34, dynamically balancing the tension. Ultimately, the tension in the three pre-oxidation zones decreases sequentially, for example, from 100 N / m to 80 N / m to 60 N / m, achieving tension gradient control that adapts to temperature gradients.

[0036] In the present invention, the tension isolation and buffer assembly 16, comprising guide rollers 19 and 20, and the wrap angle adjustment assembly, combined with a control module, allows independent tension adjustment in the three pre-oxidation zones. The buffering design of the spring damper 29 and slider 30 absorbs certain tension fluctuations and prevents wire breakage.

[0037] Therefore, this device solves the problem of carbon fiber tension mismatch under gradient temperature in the prior art through the collaboration of the tension isolation buffer component 16, the material guide component 15 and the control module; specifically, the physical mechanism of wrap angle adjustment and buffer isolation, combined with real-time feedback control, enables the tension gradient to be accurately realized.

[0038] Example 2:

[0039] See also Figures 1 to 4 、 Figure 12 and Figure 13 On the basis of Example 1, three transition cavities 36 are arranged in an array along the length direction of the top plate 8 and are respectively located directly above the three pre-oxidation zones, and the transition cavities 36 are located above the exhaust cavity 38; Three oxygen supply pipes 3 are fixedly mounted on one side of the top plate 8 near the side plate 9, each of which is connected to the three transition cavities 36. A flow valve 4 is provided in the oxygen supply pipe 3. The end of the oxygen supply pipe 3 away from the top plate 8 is connected to an external oxygen supply device. Three air ducts 7 are fixedly mounted on one side of the top plate 8 near the second side plate 10, each of which is connected to the three transition cavities 36. The end of the air duct 7 away from the top plate 8 passes through the second side plate 10 near the lower portion of the second side plate 10 to the corresponding pre-oxidation zone and is then connected to the oxygen introduction assembly. A plurality of array-distributed baffles 37 are fixedly connected to both ends of the transition cavity 36 along its length direction. The top of the baffle 37 is fixedly connected to the top surface of the transition cavity 36, and the bottom of the baffle 37 is fixedly connected to the bottom surface of the transition cavity 36. The baffle 37 is parallel to the length direction of the transition cavity 36, and the length of the baffle 37 is less than the length of the transition cavity 36. The multiple baffles 37 at both ends of the transition cavity 36 are staggered to form an S-shaped oxygen channel in the transition cavity 36.

[0040] The oxygen introduction assembly includes an oxygen supply pipe 12 fixedly installed in the oxidation zone. One end of the oxygen supply pipe 12 is closed, and the other end is fixedly connected to the end of the air guide pipe 7 away from the top plate 8.

[0041] Oxygen enters transition cavity 36 through oxygen delivery pipe 3, where it prolongs its flow time in the S-shaped path formed by interlaced baffles 37 and is preheated by the high-temperature exhaust gas in exhaust chamber 38. After preheating, the oxygen enters oxygen supply pipe 12 through air guide pipe 7 and is evenly sprayed into the pre-oxidation zone through multiple outlets 13, ensuring uniform oxidation reaction. Simultaneously, the reaction waste gas enters exhaust chamber 38 through through-hole 39 and is directed through exhaust pipe 5 to the purification system, preventing the accumulation of harmful gases such as HCN.

[0042] Among them, the S-shaped channel design of the transition cavity 36 significantly improves the oxygen preheating efficiency, reduces external heating energy consumption, and improves resource utilization.

[0043] The spacing between the gas outlets 13 of the oxygen supply tube 12 is optimized to reduce oxygen concentration deviation and avoid local overoxidation.

[0044] Example 3:

[0045] See also Figure 1Based on Example 2, three doors 2 corresponding to the three pre-oxidation zones are installed on the side of side panel 1 (9). The doors 2 of side panel 1 (9) support quick disassembly to replace the guide rollers or clean the oxygen supply pipe (12), improving the practicality of the device.

[0046] Example 4:

[0047] See also Figures 1 to 13 , based on Example 3, a control process of a control module is provided; Temperature Control: Heating element configuration: Heater 42 regulates heating power through current. A temperature sensor monitors temperature in real time and transmits the information to the control module. A gradient temperature curve is pre-set in the control module. A PID algorithm dynamically adjusts heater power to achieve gradient temperature control.

[0048] 2. Tension Gradient Generation Mechanism In the wrap angle adjustment assembly, the motor 23 drives the bidirectional screw 27 to rotate, so that the mounting strip 28 moves along the slide bar 26, changing the distance between the two guide rollers 20, thereby adjusting the wrap angle θ of the fiber.

[0049] In the buffer isolation assembly, the spring damper 29 provides stroke buffering, and the slider 30 slides to compensate for changes in fiber length, thereby isolating tension interference in adjacent temperature zones.

[0050] In the tension adjustment component 14, The electric push rod 32 drives the tension roller 34 to rise and fall, changing the fiber path length and adjusting the local tension; the tension sensor 35 provides real-time feedback data, and the control module adjusts the stroke of the electric push rod through the PID algorithm.

[0051] Control logic example: If the tension in the temperature zone is lower than the set value, the wrap angle θ between the guide roller 20 and the guide roller 1 19 is increased, and at the same time, the electric push rod 32 descends to release the fiber to maintain stable tension.

[0052] 3. Implementation of automatic adjustment: Input signals: temperature sensor, oxygen concentration sensor and tension sensor 35; Output execution: power of heater 42, speed and start / stop of motor 23, stroke of electric push rod 32, opening of flow valve 4; Specifically: Temperature-tension coupling: Automatically adjusts the guide roller wrap angle and electric push rod position according to a preset mapping table (for example, a 1°C increase in temperature results in a 0.5N / mm² decrease in tension); Feedforward compensation: When the oxygen concentration changes by more than ±5%, adjust the oxygen flow valve 4 in advance to avoid the influence of oxidation rate fluctuation on tension.

[0053] The control module can use an industrial PLC, such as the Siemens S7-1200, which supports multi-channel PID control. Its software logic is based on IEC61131-3 standard programming, calling standard library functions to implement sensor data processing and actuator driving, without involving custom algorithms. When working specifically: Startup phase: The control module loads the preset parameters (temperature gradient, target tension); The heater is heated to the target temperature and the flow valve 4 is opened to supply oxygen.

[0054] Operation phase: Temperature zone 1 (low temperature): Wrap angle θ = 120°, tension 100 N / m, to suppress fiber shrinkage; The oxygen is preheated and then sprayed evenly.

[0055] Temperature zone 2 (medium temperature): θ = 90°, tension 80 N / m, the buffer component absorbs the shrinkage stress of the cyclization reaction; The control module dynamically adjusts the electric push rod 32 to compensate for tension fluctuations.

[0056] Temperature zone 3 (high temperature): θ = 60°, tension 60 N / m, spring damper 29 to prevent brittle fracture; During the process, the exhaust pipe 5 discharges the exhaust gas to maintain a stable oxygen concentration.

[0057] During the process, if the tension suddenly changes, an emergency stop is triggered and the electric push rod 32 returns to release the fiber; Among them, PLC, PID algorithm and sensor feedback are all common industrial technologies. The present invention combines innovatively designed tension adjustment components and tension isolation buffer components with existing control technologies to achieve independent temperature control of partitions, dynamic adjustment of the guide roller wrap angle, spring damping buffering and existing control, thereby achieving precise matching of the increasing temperature gradient and decreasing tension gradient during the pre-oxidation process of carbon fiber, and improving the pre-oxidation effect of carbon fiber.

[0058] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A carbon fiber preoxidation device, comprising a preoxidation box (1) and a control module, wherein the preoxidation box (1) comprises a top plate (11), a side plate 1 (9) and a side plate 2 (10) are fixedly mounted on both sides of the top surface of the preoxidation box (1), and a top plate (8) is fixedly mounted between the top surfaces of the side plate 1 (9) and the side plate 2 (10); characterized in that: A heat insulation plate (6) is provided between both ends of the side plate 1 (9) and the side plate 2 (10), and two of the heat insulation plates (6) are installed in the pre-oxidation box (1). The four heat insulation plates (6) divide the pre-oxidation box (1) into three pre-oxidation zones, and a temperature sensor and an oxygen concentration sensor are installed in each pre-oxidation zone. A through groove (41) is provided in the middle of the side surface of the heat insulation board (6), and tension isolation buffer components (16) are fixedly mounted on the inner side surfaces of the two heat insulation boards (6) at both ends, and the tension isolation buffer components (16) are fixedly mounted on both sides of the two middle heat insulation boards (6), and material guide components (15) are fixedly mounted on both sides of the four heat insulation boards (6); A tension adjustment component (14) is fixedly installed at the middle position of the bottom of the pre-oxidation zone; An electric heater (42) and an oxygen introduction component are installed in the oxidation zone; The control module is electrically connected to the temperature sensor, the oxygen concentration sensor, the tension adjustment component (14), the oxygen supply tube (12), and the tension isolation buffer component (16).

2. A carbon fiber pre-oxidation device according to claim 1, characterized in that: The material guide assembly (15) comprises two convex plates (24) fixedly mounted on the side of the heat insulation plate (6), and the two convex plates (24) are respectively located at two end positions of the through groove (41); Two guide rollers (25) are rotatably mounted between the two convex plates (24), and the interval between the two guide rollers (25) is aligned with the through groove (41).

3. The carbon fiber pre-oxidation device according to claim 1, characterized in that: The tension isolation buffer assembly (16) includes a mounting plate (17) vertically fixedly mounted on the side of the heat insulation plate (6), the mounting plate (17) is located below the through slot (41), the top surface of the mounting plate (17) is provided with movable slots (22) near both ends, and vertical plates (18) are fixedly mounted at both ends of the top surface of the mounting plate (17), and the vertical plates (18) are aligned with the middle position of the movable slot (22); A buffer assembly is provided on the inner side of the vertical plate (18) near the top, and a guide roller (19) is rotatably installed between two groups of the buffer assemblies; An angle adjustment component used in conjunction with the guide roller 1 (19) is also fixedly mounted on the mounting plate (17).

4. A carbon fiber pre-oxidation device according to claim 3, characterized in that: The wrap angle adjustment assembly includes two guide rollers (25) fixedly mounted on the bottom surface of the mounting plate (17), a slide rod (26) fixedly connected between the two guide rollers (25), and a bidirectional screw rod (27) rotatably mounted between the two guide rollers (25); A motor (23) is fixedly mounted on the outer surface of the guide roller three (25) away from the heat insulation plate (6), and the motor (23) is electrically connected to the control module. The bidirectional screw rod (27) is rotated at one end close to the motor (23) to pass through the guide roller three (25) at the corresponding position and is fixedly connected to the output shaft end of the motor (23); The outer periphery of the bidirectional screw rod (27) is threadedly mounted with two mounting strips (28) symmetrically distributed about the guide roller 1 (19), and the mounting strips (28) are in sliding connection with the slide rod (26); Mounting seats (21) are fixedly mounted on both ends of the top surface of the mounting strip (28), and the top ends of the mounting seats (21) pass through the movable slots (22) at corresponding positions to the top of the mounting plate (17). A guide roller 2 (20) is rotatably mounted on the opposite sides of the two mounting seats (21) near the top position.

5. The carbon fiber pre-oxidation device according to claim 3, characterized in that: The buffer assembly includes a mounting groove (40) provided on the inner side of the vertical plate (18), a spring damper (29) is fixedly mounted on the bottom surface of the mounting groove (40), and a slider (30) is fixedly mounted on the top end of the spring damper (29) and is in sliding contact with the inner wall of the mounting groove (40); One end of the guide roller (19) close to the vertical plate (18) is rotatably connected to the side of the slider (30).

6. The carbon fiber pre-oxidation device according to claim 1, characterized in that: The tension adjustment assembly (14) includes an electric push rod (32) fixedly mounted on the top surface of the top plate (11), a U-shaped mounting seat (33) fixedly mounted on the top end of the electric push rod (32), and a tension sensor (35) is provided between the U-shaped mounting seat (33) and the electric push rod (32), and the tension sensor (35) and the electric push rod (32) are both electrically connected to the control module; Telescopic rods (31) are fixedly installed between the two ends of the bottom surface of the U-shaped mounting seat (33) and the top surface of the top plate (11); A tension roller (34) is rotatably mounted between the two ends of the U-shaped mounting seat (33).

7. The carbon fiber pre-oxidation device according to claim 1, characterized in that: An exhaust cavity (38) is provided in the top plate (8), and a plurality of through holes (39) are provided on the inner bottom surface of the exhaust cavity (38) above the pre-oxidation zone; An exhaust pipe (5) that is in communication with the exhaust chamber (38) is fixedly mounted on one end of the top plate (8) close to the downstream, and an end of the exhaust pipe (5) that is away from the top plate (8) is connected to an external purification exhaust system.

8. The carbon fiber pre-oxidation device according to claim 7, characterized in that: Three transition cavities (36) are arranged in an array along the length direction of the top plate (8) and are located directly above the three pre-oxidation zones, respectively, and the transition cavities (36) are located above the exhaust cavity (38); Three oxygen supply pipes (3) are fixedly mounted on one side of the top plate (8) close to the side plate (9), and are respectively connected to the three transition cavities (36). A flow valve (4) is provided in the oxygen supply pipe (3). One end of the oxygen supply pipe (3) away from the top plate (8) is connected to an external oxygen supply device. Three air guide tubes (7) are fixedly mounted on one side of the top plate (8) close to the second side plate (10), and are respectively connected to the three transition cavities (36). One end of the air guide tube (7) away from the top plate (8) passes through the second side plate (10) at a position close to the lower part of the second side plate (10) to the corresponding pre-oxidation zone and is then connected to the oxygen introduction assembly. A plurality of array-distributed baffles (37) are fixedly connected to both ends of the transition cavity (36) along its length direction, the top of the baffle (37) is fixedly connected to the top surface of the transition cavity (36), and the bottom of the baffle (37) is fixedly connected to the bottom surface of the transition cavity (36). The baffle (37) is parallel to the length direction of the transition cavity (36), and the length of the baffle (37) is less than the length of the transition cavity (36). The plurality of baffles (37) at both ends of the transition cavity (36) are staggered to form an S-shaped oxygen channel in the transition cavity (36).

9. The carbon fiber pre-oxidation device according to claim 8, characterized in that: The oxygen introduction assembly comprises an oxygen supply pipe (12) fixedly installed in the oxidation zone, one end of the oxygen supply pipe (12) is closed, and the other end is fixedly connected to the end of the air guide pipe (7) away from the top plate (8); A plurality of air outlets (13) are arranged in an array along the length of the oxygen supply tube (12) on its periphery.

10. The carbon fiber pre-oxidation device according to claim 1, characterized in that: Three box doors (2) corresponding to the three pre-oxidation zones are installed on the side surface of the side panel 1 (9).

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