Improvement of the Control Process of the Heat Treatment of Iron Ore Pellets in the Preheating Area of the Conveyor-type Roasting Machine

The object of research is the process of heat treatment of iron ore pellets. To study it, a technological zone of pre-heating of a conveyor-type roasting machine was used. Technological process control is performed on the basis of fuzzy and incomplete information about the state of this zone. One of the main requirements regarding the functioning of the technological preheating zone is to ensure the regulatory values of the thermal and gas modes when changing the speed of movement of the conveyor belt carts. Efficiency improvement of control of these modes is provided thanks to the automatic control system, implemented on the basis of fuzzy and incomplete information on the state of the technological parameters of the zone.In the course of the study, the analysis of scientific and technical information was carried out and the analytical method determined the importance of improving the process of controlling the thermal process of processing iron ore pellets in the technological preheating zone. On the basis of experimental studies, the features of the technological process have been taken into account, it requires the improvement of the process of controlling the operation of the technological preheating zone. The mathematical model uses the temperature of the coolant of the gas-air flow, the flow rate of natural gas and air, the temperature of the pellet bed and their mass on the carriages of the conveyor belt of the machine. At the same time, the output technological parameters of the drying zone and the input parameters of the firing zone are taken into account.On the basis of solving systems of fuzzy functions and the principles of parametric identification, a mathematical model is proposed that approximates the dynamics of the thermal process of processing iron ore pellets in the technological preheating zone. The characteristics of transient processes of heat treatment of pellets obtained on mathematical models are analyzed taking into account the variable parameters of the adjacent technological zones of the machine, the consumption of natural gas and air. On the basis of mathematical modeling, studies have been carried out to determine the optimal distribution of the coolants of the gas-air flow over the technological preheating zone. The hardware and software for the automatic control system for the heat treatment of pellets taking into account the variable parameters of the coolants of the gas-air flows in the technological preheating zone has been implemented