Carbon fiber pre-oxidation device

Abstract

The present application relates to the technical field of carbon fiber production, and 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 zones by four heat insulation plates, a through groove is formed in the middle part of the side surface of the heat insulation plate, and a tension isolation buffer assembly and a material guiding assembly are fixedly installed on the heat insulation plate; a tension adjusting assembly is fixedly installed at the middle position of the bottom of the pre-oxidation zone; a heater and an oxygen introduction assembly are installed in the oxidation zone; and the present application solves the problem of carbon fiber tension mismatch under gradient temperature in the prior art through the collaborative design of the tension isolation buffer assembly, the material guiding assembly, the tension adjusting assembly and the control module.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon fiber production, in particular to a carbon fiber pre-oxidation device. BACKGROUND

[0002] In the production process of carbon fiber, the carbon fiber pre-oxidation furnace is the core equipment in the production of carbon fiber, mainly used for pre-oxidation treatment of polyacrylonitrile (PAN) precursor. In this process, PAN fiber undergoes chemical crosslinking under controlled temperature and oxidation atmosphere, forming a thermally stable ladder structure, laying the foundation for subsequent high-temperature carbonization and preventing fiber melting or deformation.

[0003] In the prior art, a carbon fiber pre-oxidation processing device is provided in the patent with application number CN202411001726.7, which includes a base, support legs are fixedly installed at the top of the four corners of the base, an oxidation box is fixedly installed at the top of the support legs, a tensioning mechanism is arranged in the oxidation box, and an oxygen supply mechanism is fixedly installed inside the oxidation box. The heater assemblies at the top and bottom of the oxidation box uniformly heat the carbon fiber through the electric heating wire. The setting of the tensioning mechanism can flexibly adjust the tensioning force of the carbon fiber.

[0004] However, the pre-oxidation processing device provided in the above patent has the following deficiencies in the use process:

[0005] According to its content, multiple tensioning mechanisms are arranged in the oxidation box, and an adjusting assembly is arranged to synchronously control the multiple 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 tensioning mechanisms in the above patent causes the carbon fiber to be subjected to the same tensioning force at different temperatures, which is mismatched with the gradient temperature. In the low-temperature stage, the fiber undergoes a severe ring-opening reaction, and the shrinkage rate is as high as 10% to 15%. If the tensioning force is insufficient, it cannot effectively inhibit the shrinkage. In the high-temperature stage, the fiber has formed a rigid ladder structure, and the toughness has decreased 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 the occurrence of broken filaments. SUMMARY

[0006] The present application aims to provide a carbon fiber pre-oxidation device to solve the problems raised in the background art.

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] A kind of carbon fiber pre-oxidation device, including pre-oxidation box and control module, the pre-oxidation box includes top plate, the top surface of the pre-oxidation box two sides are respectively fixedly installed with side plate one and side plate two, top plate is fixedly installed between the top surface of side plate one and side plate two;Heat insulation plate is arranged between the two ends of side plate one and side plate two, and two heat insulation plates are installed in the middle of pre-oxidation box, four heat insulation plates divide pre-oxidation box into three pre-oxidation zones, temperature sensor and oxygen concentration sensor are installed in the pre-oxidation zone;

[0009] The side surface middle position of the heat insulation plate is provided with a through slot, and the inner side of the two heat insulation plates at both ends is fixedly installed with tension isolation buffer assembly, the two sides of the two heat insulation plates in the middle are fixedly installed with the tension isolation buffer assembly, and the two sides of the four heat insulation plates are fixedly installed with material guiding assembly;

[0010] The middle position of the bottom of the pre-oxidation zone is fixedly installed with tension adjusting assembly;

[0011] The heater and oxygen introduction assembly are installed in the oxidation zone;

[0012] The control module is electrically connected between temperature sensor, oxygen concentration sensor, tension adjusting assembly, oxygen supply pipe and tension isolation buffer assembly.

[0013] Further, the material guiding assembly includes two lug plates fixedly installed on the side surface of the heat insulation plate, and the two lug plates are located at both ends of the through slot respectively;

[0014] Two guide rollers three are rotatably installed between the two lug plates, and the interval between the two guide rollers three is aligned with the through slot.

[0015] Further, the tension isolation buffer assembly includes a mounting plate fixedly installed vertically on the side surface of the heat insulation plate, the mounting plate is located below the through slot, the top surface of the mounting plate is provided with a movable slot at the position close to both ends, and the top surface of the mounting plate is fixedly installed with a vertical plate at both end positions, and the vertical plate is aligned with the middle position of the movable slot;

[0016] The inner side of the vertical plate is provided with a buffer assembly at the position close to the top, and a guide roller one is rotatably installed between the two buffer assemblies;

[0017] The mounting plate is also fixedly installed with an angle adjusting assembly used in cooperation with the guide roller one.

[0018] Further, the angle adjusting assembly includes two guide rollers three fixedly installed on the bottom surface of the mounting plate, a sliding rod is fixedly connected between the two guide rollers three, and a bidirectional screw rod is rotatably installed between the two guide rollers three.

[0019] A motor is fixedly installed on the outer side of the guide roller three away from the heat insulation plate. The motor is electrically connected to the control module. The end of the bidirectional screw 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.

[0020] The bidirectional lead screw has two mounting plates symmetrically distributed about the guide roller installed on its outer periphery through a threaded connection, and the mounting plates are slidably connected to the slide bar through the threaded connection.

[0021] Mounting seats are fixedly installed at both ends of the top surface of the mounting plate. The top of the mounting seat passes through the movable groove at the corresponding position to the top of the mounting plate. Guide rollers are rotatably installed on the opposite sides of the two mounting seats near the top position.

[0022] 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 surface of the mounting groove, and a slider that slides in contact with the inner wall of the mounting groove is fixedly mounted on the top of the spring damper.

[0023] One end of the guide roller near the vertical plate is rotatably connected to the side of the slider.

[0024] Furthermore, the tension adjustment assembly includes an electric push rod fixedly installed on the top surface of the top plate. A U-shaped mounting base is fixedly installed at the top of the electric push rod, and a tension sensor is provided between the U-shaped mounting base and the electric push rod. The tension sensor and the electric push rod are both electrically connected to the control module.

[0025] Telescopic rods are fixedly installed at both ends of the bottom surface of the U-shaped mounting base and between the top surface of the top plate;

[0026] Tension rollers are rotatably mounted between the two ends of the U-shaped mounting base.

[0027] Furthermore, an exhaust chamber is provided in the top plate, and multiple through holes are provided on the inner bottom surface of the exhaust chamber above the pre-oxidation zone;

[0028] An exhaust pipe communicating with the exhaust chamber is fixedly installed at the downstream end of the top plate, and the end of the exhaust pipe away from the top plate is connected to an external purification and exhaust system.

[0029] Furthermore, the top plate has three transition cavities arranged in an array along its length direction, each located directly above one of the three pre-oxidation zones, and the transition cavities are located above the exhaust chamber;

[0030] Three oxygen supply pipes, each communicating with one of the three transition cavities, are fixedly installed on the side of the top plate near the side plate. Each oxygen supply pipe is equipped with a flow valve, and the end of the oxygen supply pipe away from the top plate is connected to an external oxygen supply device.

[0031] The three air guide pipes are fixedly installed on one side of the top plate close to the second side plate and are in communication with the three transition cavities, respectively, and the ends of the air guide pipes away from the top plate are in communication with the corresponding pre-oxidation zones through the second side plate at a position close to the lower part of the second side plate.

[0032] A plurality of arrayed baffles are fixedly connected to the transition cavity along the length direction of the transition cavity, the top end of the baffle is fixedly connected to the top surface of the transition cavity, 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, the length of the baffle is less than the length of the transition cavity, the plurality of baffles at the two ends of the transition cavity are staggered, and an S-shaped oxygen channel is formed in the transition cavity.

[0033] Further, the oxygen guide assembly comprises 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 and in communication with the end of the air guide pipe away from the top plate.

[0034] A plurality of air outlets are arrayed and installed on the periphery of the oxygen supply pipe along the length direction of the oxygen supply pipe.

[0035] Further, three box doors corresponding to the three pre-oxidation zones are installed on the side surface of the first side plate.

[0036] The beneficial effects of the present application are as follows:

[0037] 1. The present application solves the problem of carbon fiber tension mismatch under gradient temperature in the prior art through the cooperation of the tension isolation buffer assembly, the material guide assembly 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] 2. The guide roller one, the guide roller two and the wrap angle adjustment assembly of the tension isolation buffer assembly, combined with the control module, realize independent adjustment of the tension of the three pre-oxidation zones. And through the buffer design of the spring damper and the sliding block, certain tension fluctuation can be absorbed to avoid broken wires.

[0039] 3. In the present application, oxygen enters the transition cavity through the oxygen supply pipe, prolongs the flow time in the S-shaped path formed by the staggered baffles, and preheats by using the high-temperature waste gas in the exhaust cavity. After preheating, the oxygen enters the oxygen supply pipe through the air guide pipe and is uniformly sprayed into the pre-oxidation zone through the multiple air outlets, ensuring the uniformity of the oxidation reaction. At the same time, the reaction waste gas enters the exhaust cavity through the through hole and is guided out to the purification system through the exhaust pipe, avoiding the accumulation of harmful gases such as HCN. The S-shaped channel design of the transition cavity significantly improves the oxygen preheating efficiency, thereby reducing external heating energy consumption and improving resource utilization. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description, obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort;

[0041] Figure 1 is a three-dimensional schematic view of the overall structure of the present application;

[0042] Figure 2 is Figure 1 a three-dimensional schematic view from another angle;

[0043] Figure 3 is a three-dimensional schematic view of the internal structure of the pre-oxidation box in the present application;

[0044] Figure 4 is a three-dimensional schematic view of the oxidation zone in the present application;

[0045] Figure 5 is a three-dimensional schematic view of the installation relationship between the tension buffer assembly and the heat insulation plate in the present application;

[0046] Figure 6 is Figure 5 an enlarged view of part A in the figure;

[0047] Figure 7 is Figure 5 a three-dimensional schematic view from another angle;

[0048] Figure 8 is Figure 7 an enlarged view of part B in the figure;

[0049] Figure 9 is Figure 5 a three-dimensional schematic view from still another angle;

[0050] Figure 10 is Figure 9 an enlarged view of part C in the figure;

[0051] Figure 11 is a three-dimensional schematic view of the tension adjusting assembly in the present application;

[0052] Figure 12 is a three-dimensional schematic view of the internal structure of the top plate in the present application Figure 1 ;

[0053] Figure 13 is a three-dimensional schematic view of the internal structure of the top plate in the present application Figure 2 ;

[0054] The reference signs in the figure are as follows:

[0055] 1-preoxidation box, 2-box door, 3-oxygen pipe, 4-flow valve, 5-exhaust pipe, 6-insulation plate, 7-air guide pipe, 8-top plate, 9-side plate one, 10-side plate two, 11-top plate, 12-oxygen supply pipe, 13-air outlet, 14-tension adjusting assembly, 15-material guiding assembly, 16-tension isolation buffer assembly, 17-mounting plate, 18-vertical plate, 19-guide roller one, 20-guide roller two, 21-mounting seat, 22-moving groove, 23-motor, 24-convex plate, 25-guide roller three, 26-sliding rod, 27-bidirectional screw rod, 28-mounting strip plate, 29-spring damper, 30-sliding block, 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 groove, 41-through groove, 42-heater. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0057] Embodiment 1

[0058] Please refer to Figures 1-11 In the embodiments of the present application, a carbon fiber pre-oxidation device includes a pre-oxidation box 1 and a control module. The pre-oxidation box 1 includes a top plate 11. Side plates one 9 and side plates two 10 are fixedly installed on both sides of the top surface of the pre-oxidation box 1. A top plate 8 is fixedly installed between the top surfaces of the side plates one 9 and the side plates two 10. The features are that the two ends of the side plates one 9 and the side plates two 10 are both provided with insulation plates 6. Two insulation plates 6 are fixedly installed in the middle of the pre-oxidation box 1. The four insulation plates 6 divide the pre-oxidation box 1 into three pre-oxidation zones. Temperature sensors and oxygen concentration sensors are installed in the pre-oxidation zones.

[0059] A through groove 41 is formed in the middle of the side surface of the insulation plate 6. Tension isolation buffer assemblies 16 are fixedly installed on the inner side surfaces of the two insulation plates 6 at both ends. Tension isolation buffer assemblies 16 are fixedly installed on both sides of the two insulation plates 6 in the middle. Material guiding assemblies 15 are fixedly installed on both sides of the four insulation plates 6.

[0060] A tension adjusting assembly 14 is fixedly installed at the middle of the bottom of the pre-oxidation zone.

[0061] A heater 42 and an oxygen introduction assembly are installed in the oxidation zone.

[0062] The control module is electrically connected with the temperature sensor, the oxygen concentration sensor, the tension adjusting assembly 14, the oxygen supply pipe 12 and the tension isolation buffer assembly 16.

[0063] The material guiding assembly 15 comprises two protruding plates 24 fixedly installed on the side of the heat insulation plate 6, and the two protruding plates 24 are respectively located at the two end positions of the through slot 41.

[0064] Two guide rollers three 25 are rotatably installed between the two protruding plates 24, and the interval between the two guide rollers three 25 is aligned with the through slot 41.

[0065] The tension isolation buffer assembly 16 comprises a mounting plate 17 vertically fixedly installed 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 a movable slot 22 at the position close to the two ends, and vertical plates 18 are fixedly installed at the two end positions of the top surface of the mounting plate 17 and aligned with the middle positions of the movable slots 22.

[0066] The inner side of the vertical plate 18 is provided with a buffer assembly at the position close to the top, and a guide roller one 19 is rotatably installed between the two buffer assemblies.

[0067] The mounting plate 17 is further fixedly installed with a wrap angle adjusting assembly used in cooperation with the guide roller one 19.

[0068] The wrap angle adjusting assembly comprises two guide rollers three 25 fixedly installed on the bottom surface of the mounting plate 17, a sliding rod 26 fixedly connected between the two guide rollers three 25, and a bidirectional screw rod 27 rotatably installed between the two guide rollers three 25.

[0069] The outer side of the guide roller three 25 away from the heat insulation plate 6 is fixedly installed with a motor 23, the motor 23 is electrically connected with the control module, and one end of the bidirectional screw rod 27 close to the motor 23 is rotatably penetrated through the corresponding position of the guide roller three 25 and fixedly connected with the output shaft end of the motor 23.

[0070] The outer periphery of the bidirectional screw rod 27 is penetratively and threadedly installed with two installation strip plates 28 symmetrically distributed with respect to the guide roller one 19, and the installation strip plates 28 are penetratively and slidably connected between the sliding rods 26.

[0071] The top surface of the installation strip plate 28 is fixedly installed with a mounting seat 21 at the two ends, the top end of the mounting seat 21 penetrates through the corresponding position of the movable slot 22 to the upper side of the mounting plate 17, and the opposite side surfaces of the two mounting seats 21 are rotatably installed with a guide roller two 20 between the positions close to the top.

[0072] The buffer assembly comprises a mounting slot 40 provided in the inner side surface of the vertical plate 18, a spring damper 29 fixedly installed on the bottom surface of the mounting slot 40, and a sliding block 30 fixedly installed on the top end of the spring damper 29 and slidably contacted with the inner wall of the mounting slot 40.

[0073] The guide roller one 19 is rotatably connected to the side surface of the sliding block 30 at one end close to the vertical plate 18.

[0074] The tension adjusting assembly 14 comprises an electric push rod 32 fixedly installed on the top surface of the top plate 11, a U-shaped mounting seat 33 fixedly installed at the top end of the electric push rod 32, and a tension sensor 35 arranged between the U-shaped mounting seat 33 and the electric push rod 32, wherein the tension sensor 35 and the electric push rod 32 are electrically connected with the control module.

[0075] The bottom surface of the U-shaped mounting seat 33 is fixedly installed with the telescopic rods 31 at both ends between the top surface of the top plate 11.

[0076] The tension rollers 34 are rotatably installed between both ends of the U-shaped mounting seat 33.

[0077] The top plate 8 is provided with an exhaust cavity 38, and a plurality of through holes 39 are arranged on the inner bottom surface of the exhaust cavity 38 above the pre-oxidation zones.

[0078] The top plate 8 is fixedly installed with an exhaust pipe 5 penetrating through the exhaust cavity 38 at one end close to the downstream, and the exhaust pipe 5 is connected to an external purification exhaust system at the end away from the top plate 8.

[0079] The oxygen supply pipe 12 is provided with a plurality of gas outlets 13 arranged along the length direction of the oxygen supply pipe 12.

[0080] When the present application is used:

[0081] The carbon fibers enter the pre-oxidation box 1 from the inlet, and pass through the three pre-oxidation zones separated by the heat insulation plates 6 in sequence. In each pre-oxidation zone, the fibers pass around the guide roller three 25 of the material guiding assembly 15 and the guide roller one 19 and the guide roller two 20 of the tension isolation and buffering assembly 16, and are finally pulled out by the winding device at the end of the process.

[0082] I. Temperature gradient setting:

[0083] Each pre-oxidation zone is independently temperature-controlled, and the three pre-oxidation zones from left to right correspond to a low-temperature zone, a medium-temperature zone, and a high-temperature zone, respectively. The low-temperature zone has a larger tension on the carbon fibers to inhibit shrinkage, and the high-temperature zone needs to reduce the tension to prevent brittle fracture.

[0084] The temperature sensor feeds back data to the control module to adjust the power of the heater 42.

[0085] II. Tension gradient adjustment suitable for the temperature gradient in different pre-oxidation zones:

[0086] The motor 23 of the wrap angle adjusting assembly drives the bidirectional screw rod 27 to drive the two installation strips 28 to slide towards or away from each other, and drives the two guide rollers 20 to move towards or away from each other, so as to change the contact wrap angle θ of the fiber and the guide roller 1 19; according to the Coulomb friction model T out =T in *e μθ , the high-temperature zone reduces the wrap angle θ and reduces the tension increase.

[0087] The spring damper 29 in the buffer assembly absorbs the tension mutation, and the sliding block 30 on the vertical plate 18 compensates the fiber length change, so as to isolate the tension interference of adjacent temperature zones.

[0088] In the tension adjusting assembly, the tension sensor 35 monitors the tension of the carbon fiber in the corresponding temperature zone in real time, the control module adjusts the electric push rod 32 to lift the tension roller 34, and the tension is dynamically balanced. Finally, the tension of the three pre-oxidation zones is sequentially reduced, for example, 100 N / m→80 N / m→60 N / m, so as to realize the tension gradient control adapting to the gradient temperature.

[0089] In the present application, through the guide roller 1 19, the guide roller 2 20 and the wrap angle adjusting assembly of the tension isolation buffer assembly 16, combined with the control module, the tension of the three pre-oxidation zones is independently adjusted. Among them, through the buffer design of the spring damper 29 and the sliding block 30, certain tension fluctuation can be absorbed, and the broken filament can be avoided.

[0090] Therefore, through the cooperation of the tension isolation buffer assembly 16, the material guiding assembly 15 and the control module, the problem of carbon fiber tension mismatch under the gradient temperature in the prior art is solved. Specifically, the physical mechanism of wrap angle adjustment and buffer isolation, combined with real-time feedback control, makes the tension gradient accurate.

[0091] Embodiment 2:

[0092] Please refer to Figures 1-4 、 Figure 12 and Figure 13 , on the basis of embodiment 1, three transition cavities 36 are arranged in the top plate 8 along the length direction of the top plate 8 and located above the three pre-oxidation zones, and the transition cavities 36 are located above the exhaust cavities 38;

[0093] The top plate 8 is fixedly installed with three oxygen supply pipes 3 on the side close to the side plate 1, the oxygen supply pipes 3 are in communication with the three transition cavities 36, flow valves 4 are arranged in the oxygen supply pipes 3, and one ends of the oxygen supply pipes 3 away from the top plate 8 are connected with external oxygen supply equipment;

[0094] Three air guide pipes 7 are fixedly installed on the top plate 8 near one side of the second side plate 10 and penetrate the three transition cavities 36, and the ends of the air guide pipes 7 far from the top plate 8 penetrate the second side plate 10 at the lower part near the second side plate 10 to be connected with the oxygen guide assembly in the corresponding pre-oxidation zone.

[0095] A plurality of arrayed baffles 37 are fixedly connected at both ends of the transition cavity 36 along the length direction of the transition cavity 36, the top ends of the baffles 37 are fixedly connected with the top surface of the transition cavity 36, the bottom ends of the baffles 37 are fixedly connected with the bottom surface of the transition cavity 36, the baffles 37 are parallel to the length direction of the transition cavity 36, the length of the baffles 37 is less than the length of the transition cavity 36, and the plurality of baffles 37 at both ends of the transition cavity 36 are staggered arranged to form an S-shaped oxygen passage in the transition cavity 36.

[0096] The oxygen guide 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 and penetratingly connected with the end of the air guide pipe 7 far from the top plate 8.

[0097] The oxygen enters the transition cavity 36 through the oxygen supply pipe 3, and the oxygen flow time is prolonged in the S-shaped path formed by the staggered baffles 37, and the oxygen is preheated by the high-temperature waste gas in the exhaust cavity 38. After preheating, the oxygen enters the oxygen supply pipe 12 through the air guide pipe 7, and is uniformly sprayed into the pre-oxidation zone through a plurality of air outlets 13, so as to ensure the uniformity of the oxidation reaction. At the same time, the reaction waste gas enters the exhaust cavity 38 through the through hole 39, and is discharged to the purification system through the exhaust pipe 5, so as to avoid the accumulation of harmful gases such as HCN.

[0098] The S-shaped passage design of the transition cavity 36 significantly improves the oxygen preheating efficiency, reduces the external heating energy consumption, and improves the resource utilization rate.

[0099] The air outlets 13 of the oxygen supply pipe 12 are optimized in spacing, the oxygen concentration deviation is reduced, and local over-oxidation is avoided.

[0100] Example 3:

[0101] Please refer to Figure 1 On the basis of example 2, three box doors 2 are installed on the side of the first side plate 9 and correspond to the three pre-oxidation zones. The box doors 2 of the first side plate 9 support quick disassembly, replacement of the guide roller or cleaning of the oxygen supply pipe 12, and improve the practicability of the device.

[0102] Example 4:

[0103] Please refer to Figures 1-13 On the basis of example 3, the control process of the control module is provided.

[0104] Temperature control: Heating element configuration: The heater 42 adjusts the heating power by current; the temperature sensor monitors the temperature in real time and transmits it to the control module. The control module has a preset gradient temperature curve; the PID algorithm is used to dynamically adjust the heater power, so as to realize the control of the gradient temperature.

[0105] II. Tension gradient generation mechanism

[0106] In the wrap angle adjustment assembly, the motor 23 drives the bidirectional screw rod 27 to rotate, so that the installation strip plate 28 moves along the slide rod 26, the distance between the two guide rollers 20 is changed, and the wrap angle θ of the fiber is adjusted.

[0107] In the buffer isolation assembly, the spring damper 29 provides stroke buffering, and the sliding block 30 slides to compensate for the change of the fiber length, so as to isolate the tension interference of adjacent temperature zones.

[0108] In the tension adjustment assembly 14,

[0109] The electric push rod 32 drives the tension roller 34 to rise and fall, changes the fiber path length, and adjusts the local tension; the tension sensor 35 feeds back data in real time, and the control module adjusts the electric push rod stroke through the PID algorithm.

[0110] Control logic example: If the temperature zone tension is lower than the set value, increase the wrap angle θ of the guide roller two 20 and the guide roller one 19, and at the same time, the electric push rod 32 is lowered to release the fiber, so as to maintain the stability of the tension.

[0111] III. Realization of automatic adjustment:

[0112] Input signal: temperature sensor, oxygen concentration sensor and tension sensor 35;

[0113] Output execution: power of the heater 42, rotating speed of the motor 23 and start-stop, stroke of the electric push rod 32, opening degree of the flow valve 4;

[0114] Specifically:

[0115] Temperature-tension coupling: According to the preset mapping table (for example, when the temperature rises by 1°C, the tension decreases by 0.5N / mm²), the wrap angle of the guide roller and the position of the electric push rod are automatically adjusted;

[0116] Feedforward compensation: When the oxygen concentration changes by more than ±5%, the oxygen supply flow valve 4 is adjusted in advance to avoid the influence of the oxidation rate fluctuation on the tension.

[0117] Among them, the control module can adopt an industrial PLC, such as Siemens S7-1200, which supports multi-channel PID control; the software logic is programmed based on the IEC61131-3 standard, and the standard library functions are called to realize sensor data processing and actuator driving, without involving self-defined algorithms;

[0118] Specific work:

[0119] Start-up phase:

[0120] The control module loads preset parameters (temperature gradient, target tension);

[0121] The heater is heated to the target temperature, and the flow valve 4 is opened to supply oxygen.

[0122] Running phase:

[0123] Temperature zone 1 (low temperature):

[0124] The included angle θ=120°, the tension is 100 N / m, and the fiber shrinkage is inhibited;

[0125] The oxygen is uniformly sprayed after preheating.

[0126] Temperature zone 2 (medium temperature):

[0127] θ=90°, tension 80 N / m, and the buffer assembly absorbs the shrinkage stress of the cyclization reaction;

[0128] The control module dynamically adjusts the electric push rod 32 to compensate for tension fluctuations.

[0129] Temperature zone 3 (high temperature):

[0130] θ=60°, tension 60 N / m, and the spring damper 29 prevents brittle fracture;

[0131] During the process, the exhaust pipe 5 discharges waste gas to maintain stable oxygen concentration.

[0132] During the process, if the tension suddenly changes, the emergency stop is triggered, and the electric push rod 32 returns to release the fiber;

[0133] Among them, PLC, PID algorithm, sensor feedback are all industrial general technologies

[0134] In the present application, through the innovative design of the tension adjusting assembly and the tension isolation buffer assembly, and the combination with the existing control technology, the independent temperature control of the partition, the dynamic adjustment of the guide roller included angle, the spring damping buffer and the existing control are realized, so that the precise matching of the temperature gradient increase and the tension gradient decrease in the carbon fiber pre-oxidation process is realized, and the pre-oxidation effect of the carbon fiber is improved.

[0135] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A carbon fiber pre-oxidation device, comprising a pre-oxidation box (1) and a control module, the pre-oxidation box (1) comprising a top plate (11), the top surface of the pre-oxidation box (1) being fixedly installed with a side plate one (9) and a side plate two (10) on both sides respectively, and the top surface of the side plate one (9) and the side plate two (10) being fixedly installed with a top plate (8); characterized in that, The both ends of the side plate one (9) and the side plate two (10) are provided with heat insulation plates (6), and two heat insulation plates (6) are arranged in the pre-oxidation box (1), and the four heat insulation plates (6) divide the pre-oxidation box (1) into three pre-oxidation areas, and temperature sensors and oxygen concentration sensors are arranged in the pre-oxidation areas; The middle part of the side surface of the heat insulation plate (6) is provided with a through groove (41), and the inner side surfaces of the two heat insulation plates (6) at both ends are fixedly provided with tension isolation buffer assemblies (16), and the both sides of the two heat insulation plates (6) in the middle are fixedly provided with the tension isolation buffer assemblies (16), and the both sides of the four heat insulation plates (6) are fixedly provided with material guiding assemblies (15); The middle part of the bottom of the pre-oxidation area is fixedly provided with a tension adjusting assembly (14); The oxidation area is provided with an electric heater (42) and an oxygen inlet assembly; The control module is electrically connected with the temperature sensor, the oxygen concentration sensor, the tension adjusting assembly (14), the oxygen supply pipe (12) and the tension isolation buffer assembly (16); The material guiding assembly (15) comprises two lug plates (24) fixedly arranged on the side surface of the heat insulation plate (6), and the two lug plates (24) are located at both ends of the through groove (41) respectively; Two guide rollers three (25) are rotatably arranged between the two lug plates (24), and the interval between the two guide rollers three (25) is aligned with the through groove (41); The tension isolation buffer assembly (16) comprises a mounting plate (17) fixedly arranged vertically on the side surface of the heat insulation plate (6), the mounting plate (17) is located below the through groove (41), the top surface of the mounting plate (17) is provided with a movable groove (22) at both ends, and the top surface of the mounting plate (17) is fixedly provided with a vertical plate (18) at both ends, and the vertical plate (18) is aligned with the middle part of the movable groove (22); The inner side of the vertical plate (18) is provided with a buffer assembly at a position close to the top, and a guide roller one (19) is rotatably arranged between the two buffer assemblies; An angle adjusting assembly is also fixedly arranged on the mounting plate (17) and cooperates with the guide roller one (19); An exhaust cavity (38) is arranged in the top plate (8), and a plurality of through holes (39) are arranged in the inner bottom surface of the exhaust cavity (38) and above the pre-oxidation area; An exhaust pipe (5) is fixedly arranged at one end of the top plate (8) close to the downstream and penetrates the exhaust cavity (38), and the other end of the exhaust pipe (5) is connected to an external purification exhaust system; Three transition cavities (36) are arranged in the top plate (8) and above the pre-oxidation area along the length direction of the top plate (8), and the transition cavities (36) are located above the exhaust cavity (38); Three oxygen supply pipes (3) are fixedly arranged at one side of the top plate (8) close to the side plate one (9) and penetrate the three transition cavities (36) respectively, and the oxygen supply pipes (3) are provided with flow valves (4), and the other ends of the oxygen supply pipes (3) are connected to an external oxygen supply device; Three air guide pipes (7) are fixedly installed on one side of the top plate (8) close to the second side plate (10), and each air guide pipe (7) penetrates through a transition cavity (36); one end of the air guide pipe (7) away from the top plate (8) penetrates through the second side plate (10) at a position close to the lower part of the second side plate (10) into the corresponding pre-oxidation area and is connected with the oxygen guide-in assembly; A plurality of arrayed baffles (37) are fixedly connected at both ends of the transition cavity (36) along the length direction of the transition cavity (36); the top end of the baffle (37) is fixedly connected with the top surface of the transition cavity (36), the bottom end of the baffle (37) is fixedly connected with the bottom surface of the transition cavity (36), the baffle (37) is parallel to the length direction of the transition cavity (36), the length of the baffle (37) is less than the length of the transition cavity (36), and the plurality of baffles (37) at both ends of the transition cavity (36) are staggered arranged to form an S-shaped oxygen passage in the transition cavity (36).

2. The carbon fiber pre-oxidation device according to claim 1, wherein The wrap angle adjusting assembly comprises two guide rollers three (25) fixedly installed on the bottom surface of the mounting plate (17), a sliding rod (26) fixedly connected between the two guide rollers three (25), and a bidirectional screw rod (27) rotatably installed between the two guide rollers three (25). A motor (23) is fixedly installed on the outer side of the guide roller three (25) away from the heat insulation plate (6); the motor (23) is electrically connected with the control module; one end of the bidirectional screw rod (27) close to the motor (23) is rotatably penetrated through the guide roller three (25) at the corresponding position and is fixedly connected with the output shaft end of the motor (23). Two installation strip plates (28) symmetrically distributed with respect to the guide roller one (19) are threadedly installed on the periphery of the bidirectional screw rod (27); the installation strip plate (28) and the sliding rod (26) are through slidingly connected. The top surface of the installation strip plate (28) is fixedly installed with an installation seat (21) at both ends; the top end of the installation seat (21) penetrates through the movable slot (22) at the corresponding position to the upper side of the mounting plate (17); the opposite side surfaces of the two installation seats (21) are rotatably installed with guide rollers two (20) at the positions close to the top.

3. The carbon fiber pre-oxidation device according to claim 1, wherein The mounting slot (40) is provided in the inner side surface of the vertical plate (18); the bottom surface of the mounting slot (40) is fixedly installed with a spring damper (29); the top end of the spring damper (29) is fixedly installed with a sliding block (30) in sliding contact with the inner wall of the mounting slot (40). The end of the guide roller one (19) close to the vertical plate (18) is rotatably connected with the side surface of the sliding block (30).

4. The carbon fiber pre-oxidation device according to claim 1, wherein The tension adjusting assembly (14) comprises an electric push rod (32) fixedly installed on the top surface of the top plate (11); the top end of the electric push rod (32) is fixedly installed with a U-shaped installation seat (33); a tension sensor (35) is arranged between the U-shaped installation seat (33) and the electric push rod (32); the tension sensor (35) and the electric push rod (32) are electrically connected with the control module; The bottom surface of the U-shaped installation seat (33) is fixedly installed with an expansion rod (31) at both ends; A tension roller (34) is rotatably mounted between the two ends of the U-shaped mounting seat (33).

5. The carbon fiber pre-oxidation device according to claim 1, wherein The oxygen introduction assembly comprises an oxygen supply pipe (12) fixedly installed in the oxidation zone, one end of the oxygen supply pipe (12) being closed and the other end being fixedly and throughly connected with the end of the gas guide pipe (7) away from the top plate (8). A plurality of gas outlets (13) are arrayed along the length direction of the periphery of the oxygen supply pipe (12).

6. The carbon fiber pre-oxidation device according to claim 1, wherein Three cabinet doors (2) corresponding to the three pre-oxidation zones are installed on the side of the side plate one (9).

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