Evaluation of a Simulation Model for Deep-Bed Drying of Hybrid Rice Seeds

Abstract

This study evaluates a simulation model for drying hybrid rice seeds in deep-bed set-up. This model is based on a heterogeneous diffusion model for predicting grain moisture at different levels on a deep-bed drying set-up was developed. To evaluate this, hybrid rice seeds were dried in a laboratory dryer with a 50-cm depth test cell. Three drying setups (45°C, 55°C, and stepwise) were used. During drying, moisture content was measured at different levels of the cell and at specified time intervals. Around four months after storage, germination percentage of samples from different drying setting and grain locations were obtained. The drying experiment revealed that the fastest drying time is achieved with the 55°C drying temperature. Parameter estimation and model validation of the simulation have revealed that the model used can well predict the moisture content of the seeds across the deep-cell drying bin at any given time. This can be further supported by the mean relative error of the model which is below its acceptable values. Germination results have also shown that the drying procedures used have no negative effect on the seed quality. Thus, using the simulation model could be an accurate way to predict the moisture content with no effect on its seed quality.