A THIN-LAYER DRYING MODEL FOR PADDY DRYER

Precision control of drying conditions is very important in conducting thin-layer drying experiment on agricultural products. For control of drying it is necessary to determine drying kinetics, and obtain the moisture change during the drying process. In order to carry out the experiments a generalpurpose fully automated thin-layer dryer was designed and tested. Experiments on the drying kinetics of paddy (Fajr variety) were conducted at five drying air temperatures, ranging from 30 to 70 C o , in four air velocities, ranging from 0.25 to 1.0 m/s. During the drying the mass loss of samples measured continuously with a digital balance. Drying curves obtained from the experimental data were fitted to nine thin layer models. Results showed that two-term model predicts moisture change in drying with higher accuracy than other models.