CN-117702311-B - System and method for adjusting oxidation degree of fibers

CN117702311BCN 117702311 BCN117702311 BCN 117702311BCN-117702311-B

Abstract

The invention discloses a fiber oxidation degree adjusting system, namely a method, which comprises an oxidation furnace, a detection module and a gas adjusting module, wherein the oxidation furnace is used for oxidizing fibers, the detection module is arranged at a filament outlet of the oxidation furnace and used for detecting the oxygen content of the oxidized fibers in real time and generating an adjusting signal based on the oxygen content, the gas adjusting module is arranged at a position of an air inlet of the oxidation furnace and used for inputting mixed gas into the oxidation furnace, and the gas adjusting module is in communication connection with the detection module and is used for adjusting the oxygen content of the mixed gas input into the oxidation furnace according to the adjusting signal. According to the invention, the regulating signal is generated by detecting the change amount of the oxidized fiber weight in real time, so that the oxygen content of the mixed gas in the oxidation furnace is regulated, the real-time regulation of the fiber oxidation degree is realized, the regulation is convenient and quick, the occurrence of the regulation hysteresis of the fiber oxidation degree is avoided, the difference of the oxygen content of the fiber in unit volume is reduced, and the performance of the fiber is improved.

Inventors

ZHANG JIANGUO
SUN HAICHENG
ZHOU YUZHU
ZHANG HONGXIANG

Assignees

陕西天策新材料科技有限公司

Dates

Publication Date: 20260512
Application Date: 20231222

Claims (10)

1. The fiber oxidation degree adjusting system is characterized by comprising an oxidation furnace (6), a detection module and a gas adjusting module: The oxidation furnace (6) is used for oxidizing the fibers (7); the detection module is arranged at the filament outlet of the oxidation furnace (6) and is used for detecting the oxygen content of the oxidized fibers (7) in real time and generating an adjusting signal based on the oxygen content; wherein the detection module comprises a fiber winder (8) and a balancing weight (10); the fiber winder (8) is arranged at the filament outlet of the oxidation furnace (6) and is used for winding N circles of fibers (7); The fiber winder (8) is connected with one end of a lever, the other end of the lever is connected with the balancing weight (10), a sensor (9) is arranged on the lever, and the sensor (9) is used for acquiring a swinging signal of the lever to generate the adjusting signal when the weight of the fiber (7) wound on the fiber winder (8) and with a set length changes; the sensor (9) is in communication connection with the gas conditioning module, transmitting the conditioning signal to the gas conditioning module; The gas regulating module is arranged at the position of the gas inlet of the oxidation furnace (6) and is used for inputting mixed gas into the oxidation furnace (6), and the gas regulating module is in communication connection with the detection module and is used for regulating the flow of the mixed gas input into the oxidation furnace (6) and the oxygen content in the mixed gas according to the regulating signal.
2. A fibre oxidation degree adjustment system according to claim 1, characterized in that the gas adjustment module comprises a gas mixer (3), wherein two gas inlets are provided on the gas mixer (3), one of the gas inlets being connected to an oxidizing gas source and the other gas inlet being connected to a rare gas source; an air inlet of an oxygen analyzer (4) is connected to an air outlet of the gas mixer (3), and an air outlet of the oxygen analyzer (4) is connected to an air inlet of the oxidation furnace (6).
3. The fiber oxidation degree adjusting system according to claim 2, wherein a third flow controller (5) is arranged on a connecting pipeline of the air outlet of the oxygen analyzer (4) and the air inlet of the oxidation furnace (6), and the third flow controller (5) is in communication connection with the sensor (9) and is used for controlling the flow of the mixed gas entering the oxidation furnace (6) according to the adjusting signal.
4. The fiber oxidation degree adjusting system according to claim 2, wherein a first flow controller (1) is arranged between the oxidizing gas source and one of the gas inlets on the gas mixer (3), a second flow controller (2) is arranged between the rare gas source and the other gas inlet of the gas mixer (3), and the first flow controller (1) and the second flow controller (2) are respectively in communication connection with the sensor (9) for respectively adjusting the flow rate of the gas entering the gas mixer (3) according to the adjusting signal.
5. The system of claim 2, wherein the oxidizing gas is oxygen and the noble gas is one of nitrogen, argon or helium.
6. A method for regulating the oxidation degree of a fiber using the system according to any one of claims 1 to 5, comprising: Setting fiber oxidation parameters and oxidizing the initial fiber section; winding the oxidized fiber initial section on a fiber winder for a set length, then dragging the end of the fiber to a fiber lower-stage treatment procedure, adjusting a balancing weight to balance a lever, starting to prepare the fiber, and driving the fiber winder to rotate; The method comprises the steps of obtaining a swinging angle and a swinging direction of a lever based on the change of the weight of a fiber wound on a fiber winder and with a set length through a sensor in the fiber preparation process, and generating an adjusting signal based on the swinging angle and the swinging direction of the lever; and adjusting the oxygen content of the mixed gas in the oxidation furnace in real time based on the adjusting signal, so as to adjust the oxidation degree of the fiber.
7. The method according to claim 6, wherein adjusting the oxygen content of the mixed gas in the oxidation furnace in real time based on the adjustment signal comprises obtaining the adjustment signal by a third flow controller, and adjusting the flow rate of the mixed gas inputted into the oxidation furnace by the gas mixer.
8. The method of claim 6, wherein adjusting the oxygen content of the mixed gas in the oxidation oven in real time based on the adjustment signal comprises adjusting the ratio of the input gas to the gas mixer based on the adjustment signal by the second flow controller and the first flow controller to change the oxygen content of the mixed gas in the gas mixer.
9. The method according to claim 6, wherein the oxygen content is detected by using an oxygen analyzer when the mixed gas in the gas mixer is fed into the oxidation furnace.
10. The method of claim 6, wherein the fiber is wound on the fiber winding device for 5-10 turns.

Description

System and method for adjusting oxidation degree of fibers Technical Field The invention belongs to the technical field of carbon fiber production, and particularly relates to a fiber oxidation degree adjusting system and method. Background Carbon fibers are fibrous carbon materials, have a lower density than metallic aluminum, but have a higher strength than steel, and have properties such as corrosion resistance and high modulus, which have a close relationship with the processing process of carbon fibers. Among them, the oxidation treatment in the production of carbon fibers has a great influence on the characteristics of the carbon fibers. The oxidation treatment of the carbon fiber is usually carried out in an oxidizing gas atmosphere, the main technological parameters of the oxidation treatment are temperature, time, oxidant type and the like, the carbon fiber can undergo cross-linking polymerization of organic molecules in the oxidation reaction process of the carbon fiber, alkyl carbon forms active points, carbonyl groups, carboxyl groups and phenoxy groups are formed through the intervention of oxygen, the softening point of the carbon fiber is improved, and the carbon fiber cannot be fused and thermally decomposed in the subsequent carbonization graphitization treatment at a higher temperature. The oxygen content of the carbon fiber after the oxidation treatment is increased, for the mesophase pitch fiber with the diameter below 20 mu m, the oxygen content of the carbon fiber after the oxidation is 6% -10%, if the oxygen content is too low, the oxidation is insufficient, and if the oxygen content is too high, the strength of the final carbon fiber can be reduced, and meanwhile, the carbon fiber is required to be uniformly oxidized in the oxidation treatment process of the carbon fiber, namely, the oxygen content difference from the surface of the carbon fiber to the core part per 1 mu m volume depth is controlled within 1%, so that the carbon fiber is prevented from forming a sheath-core structure with low core oxygen content and high surface oxygen content. At present, carbon fibers are produced and prepared sequentially through steps of melt spinning, oxidation, carbonization, graphitization and the like, oxygen content detection is carried out on the prepared carbon fibers, visual detection on the oxygen content in the carbon fibers is carried out by detecting the density of the carbon fibers, namely, judging the density change of the carbon fibers by utilizing the weight change of the carbon fibers with specific lengths, reflecting the difference of the oxidation degrees of the carbon fibers, and then adjusting the oxidation parameters of the carbon fibers according to the reflected difference of the oxidation degrees of the carbon fibers. In the production of carbon fibers, oxidation is an intermediate step of a processing procedure, and the oxidation degree of the carbon fibers is fed back by detecting the oxygen content of the prepared carbon fibers or the final carbon fiber performance, so that serious hysteresis exists, and further the oxidation parameters in the carbon fiber production step cannot be timely adjusted in real time, and the actual effect of oxidation treatment cannot be reflected in real time in the production process, so that the oxygen content error in the unit volume of the produced carbon fibers is large, the production defective rate of the carbon fibers is high, and the production cost is high. Disclosure of Invention In order to solve the problems that in the prior art, after oxidization, the oxidization parameters of the carbon fiber cannot be regulated in real time, and oxidization feedback hysteresis exists, so that the production cost is high, the invention provides a fiber oxidization degree regulating system, and meanwhile, the invention also provides a fiber oxidization degree regulating method based on the system. In order to achieve the above purpose, the present invention provides the following technical solutions: a fiber oxidation degree adjusting system comprises an oxidation furnace, a detection module and a gas adjusting module: The oxidation furnace is used for oxidizing the fibers; the detection module is arranged at the filament outlet of the oxidation furnace and is used for detecting the oxygen content of the oxidized fibers in real time and generating an adjusting signal based on the oxygen content; The gas regulating module is arranged at the position of the gas inlet of the oxidation furnace and used for inputting mixed gas into the oxidation furnace, and is in communication connection with the detection module and used for regulating the flow of the mixed gas input into the oxidation furnace and the oxygen content in the mixed gas according to the regulating signal. Preferably, the detection module comprises a fiber winder and a balancing weight; The fiber winder is arranged at the filament outlet of the oxidation furnace and is used for windi