Mass Transfer Kinetics And Control In Coagulation Bath Of Carbon Fiber Precursor

Carbon fiber has high strength, high modulus, corrosion resistance, high temperature resistance and other excellent performance, and it is widely used in military and civilian fields. On the one hand, there is a huge gap between the quality of China’s carbon fiber precursor and that of foreign countries’. On the other hand, the other countries keep secret the core technology of carbon fiber precursor. So that the study of carbon fiber precursor’s forming has great significance. The process of coagulation bath is the most important link of carbon fiber precursor’s forming so that the study on coagulation bath has direct significance on improving the quality of our carbon fiber.This paper carries a research on mass transfer kinetics and control of coagulation bath which are respectively based on double diffusion and production.Firstly, it would study on the mass transfer kinetics in the process of coagulation. Based on Fick Theory, it would introduce the classical diffusion models of solvent and non solvent, make numerical simulation analysis on the model, then study on diffusion coefficient which is the most important parameter in the diffusion process, make numerical simulation analysis and discuss the relationship between the diffusion.:; coefficient and other parameters, such as spinneret hole radius, concentration, temperature, etc.Secondly, it would make a research on and a simulation analysis on the radial diffusion model in the process of coagulation. By use of the strong numerical computing ability of MATLAB and the programming, It would obtain the mathematical model of the spinning radial diffusion and the distribution map of components’mean concentration of fiber cross-section by the finite element method, and examine the spinning conditions’effect on coagulation time.Thirdly, based on the decoupling control of the coagulation bath’s multivariable coupling system and the industrial control model of producing the carbon fiber’s coagulation bath, this paper would design and simulate the decoupling control of this typical multivariable coupling system, perform the decoupling control of the coagulation bath’s three parameters—liquid level, temperature and concentration by combining a kind of feed-forward-like decoupling controller and PID control, and compare them with the conventional PID controller. As a result, the simulation results show that the controller realizes the decoupling control on these coupling parameters in order to implement the high-quality control on the coagulating bath process.Finally, this paper would summarize the thesis, point out the deficiencies existing in my current research, and look forward to the next research direction in the related field in the future.