HEAT-TRANSFER SIMULATION ON DRYING PROCESSES OF NONFIRED PELLETS CONTAINING COMBINED WATER IN THE MOVING BED REACTOR

Attention has been focussed on nonfired pellets used in ironmaking industries from the point of view of energy saving. Heat transfer experiments for nonfired pellets were carried out for the better understanding of the fundamental process characteristics which would provide the basis for utilization technology of nonfired pellets. Heat transfer characteristics were investigated by both numerical simulation and experiments using moving beds. Decomposition rate of combined water contained in the nonfired pellets and temperature dependence of effective thermal conductivity were measured by means of TG-DTA and laser flash method, respectively. Heat transfer coefficient between gas and solid in the moving bed was determined by using fired pellets and a correlated equation was proposed. One dimensional mathematical model developed here provided excellent agreement between estimated temperature distribution in the moving beds and observed data.