NUMERICAL SIMULATION OF GAS-SOLID HEAT TRANSFER AND MOISTURE EVAPORATION PROCESS IN PREHEATING SHAFT KILN FOR FERROMAGNESIUM PELLETS

The arc furnace is an important equipment in the production of manganese ferroalloys. In the smelting process, it produces high temperature flue gas above 700 K, which has high utilization value. During the pelleting process, moisture exists on the surface and inside of the pellets, which, if directly fed into the arc furnace, will lower the temperature of the furnace, affecting the production, and will also cause the pellets to burst, resulting in pressure fluctuations in the furnace and other hazards. The preheating shaft kiln reduces the moisture content of the pellet while preheating the pellet by utilizing high temperature flue gas. In this paper, through the establishment of porous media and shrinking core coupling mathematical model, to achieve the prediction of the heating and drying process of the pellets of various particle sizes, which is in good agreement with the production monitoring data. The results show that 9 similar to 11 mm pellets have the best preheating effect in terms of tail gas temperature, pellet temperature and preheating time.