SIMULATION OF LOW-TEMPERATURE ROUGH RICE DRYING AND REWETTING IN SHALLOW BEDS

Equilibrium simulation model was used for estimating the drying and re wetting of long-grain rough rice in shallow beds due to forced aeratio n. Limitations of the simulation model were examined for the relative influences of grain layer thickness, time step, and airflow rate on pr edicted moisture content profiles in grain beds. A value of grain dry matter-to-air ratio equal to or greater than 0.27 based on 1-h time st ep was determined to yield close agreement between experimental and si mulated moisture content profiles. Under such conditions, the simulate d moisture content profiles were insensitive to the changes either in layer thickness or time step for a fixed value of grain dry matter-to- air ratio based on 1-h time step. Results showed that equilibrium mode l predicted rough rice drying and rewetting in shallow-beds reasonably well when the developed criterion for grain dry matter-to-air ratio w as applied in the simulation scheme.