Abstract
Application of numerical simulation of a drying process by a computer has become an essential procedure in design of a grain dryer and for finding the optimum drying conditions, and then the drying model is required to have a high accuracy and adaptability to many different rice varieties on which the numerical simulations are based.
In this study, the drying characteristics of four Japonica and two Indica varieties of rough rice were investigated by a thin-layer drying experiment. It was proved that two-tank model presented in previous papers could predict their drying characteristics with high accuracy. Relationship between the boundary time θk defined in previous papers and the residence time of rough rice in a drying chamber of a recirculating dryer was discussed. It was proposed that the optimum residence time could be decided based on the drying characteristics of each variety. Moreover, it was mentioned that the least square method for estimating model parameters should be applied with some modifications usefully.
