Design And Analysis Of Hot Mill Grinding Blade Gap Control System Based On Current Signal

The grinding pad gap refers to the vertical distance between the surface of the movable grinding disc and the fixed grinding disc in the grinding chamber of the hot mill,and its size is one of the important reasons affecting the fiber separation quality and energy consumption.In actual production,in order to ensure the fiber separation quality,the grinding plate gap should be controlled within the range of 0.2～0.5mm,but the pre-set grinding plate gap will change due to the wear of grinding plate,grinding pressure and change of feeding volume,which will affect the stability of fiber separation quality.In order to improve the fiber separation quality and meet its production requirements,a grinding blade gap automatic control system is designed to automatically adjust the grinding blade gap size during the operation of the hot mill.The gap automatic control system designed in this paper adopts mechanical transmission device to adjust the grinding blade gap,with the input current of the main motor of the hot mill as the main control parameter,and after using PSO-PID controller correction and optimization,it can realize the automatic adjustment and control of the grinding blade gap to improve the fiber separation quality and the working efficiency of the hot mill.The main research contents of this paper are as follows:The scatter plot and linear regression equation of the process parameters and operation parameters of the hot mill on fiber separation quality,energy consumption per unit power and output were established separately using Excel to verify the effects of steam pressure,material level height,discharge valve opening size,discharge screw speed and grinding blade clearance on fiber quality,and to illustrate the importance of grinding blade clearance in controlling fiber quality and affecting fiber output and energy consumption of the hot mill.According to the mechanical hot mill transmission device,the transfer functions of the grinding blade gap control system transmission device,gap adjustment device and other links are established and the parameters are calculated to obtain the mathematical model of the gap control system.Using Matlab/simulink numerical simulation software to build the system simulation model,analyze the stability,rapidity and accuracy of the system,and judge the system performance.For the instability of the system,the mathematical model of the control system is established by using AMEsim software,and the system model is corrected by using the PSO-PID controller combining PID control and PSO particle swarm algorithm.Analyze the control performance of the corrected system: analyze the steady-state response of the system input sinusoidal input signal to verify the system response speed;analyze the regulation effect of the system input unit error to verify the system control accuracy;analyze the system gap regulation ability when the system input different loads to verify the system anti-interference ability.The results show that the automatic control system of hot mill grinding gap based on current signal designed in this paper has the advantages of fast response,high control accuracy and strong anti-interference ability,which meets the requirements of the control system of hot mill grinding gap and can realize the automatic adjustment of the grinding gap of hot mill.