Research Of Intelligent Control System In Fluidized Gypsum Calcination Process

Industrial by-product gypsum is mainly utilized to produce the building plaster in fluidizedgypsum calcining craft, which is the most important way of to handle chemical gypsum in ourcountry. Gypsum calcination process is to transform the dihydrate gypsum to hemihydrategypsum. If the temperature is low, there will be too much dihydrate gypsum which will affectthe product’s hardness greatly. Oppositely, there will be too much anhydrite content and extraenergy will be wasted when the temperature is high. Therefore, temperature control ofindustrial gypsum calcinations will significantly affect the comprehensive utilization ofindustrial gypsum.At present, conventional PID control is often used in domestic gypsum calcinationsprocess. However, it is difficult to obtain better control effect owing to the load disturbance andother factors in the actual production process which lead to the obvious change of processes’model. Considering all the factors, developing an intelligent control system for a gypsumcalcining is of great significance.In this paper, the fluidized gypsum calcining system is divided into two parts: thepre-drying system and the calcined system. In the pre-drying subsystem, fuzzy-PID controllerwhich is characterized by high-precision and strong robustness is utilized considering theexistence of more uncertain disturbances. And PID parameters can be adjusted online with thechange of working condition. In calcined system, in view of the change of mathematical model,two kinds of IMC controllers are designed in order to adapt to the specific circumstances ofcalcined system. Which are conventional internal model controller and intelligent internalmodel controller with three degrees of freedom separately. The conventional internal modelcontroller is used when the disturbance is smaller and three degrees of freedom intelligentinternal model controller is adopted when the disturbance is bigger.In the pre-drying system, the simulation results show that fuzzy PID control system hashigher speed and stronger anti-disturbance compared with the conventional PID. In calcinedsystem, simulation results show that the conventional internal model controller has better effectwith lower overshoot and stronger robustness compared with traditional PID, which achievesthe requirements of temperature system. Moreover, compared with the ordinary three degrees of freedom of internal model controller, three degrees of freedom of intelligent internal modelcontroller has shorter regulation time and better anti-interference ability, can achieve fasttracking of the temperature’s set value.In this paper, the designed intelligent control algorithms are embedded into the DCScontrol system using OPC technology. a intelligent control application software is designed onthe platform of visual studio2008，and the field application results prove the effectiveness ofthe control.