Modelling drying kinetics of paddy in swirling fluidized bed dryer

Drying kinetic model of paddy at specific drying time under different capacities drying conditions were studied under swirling fluidized bed (SFB) dryer. The drying was performed at capacities of 1, 2, and 3 kg, temperatures of 55 °C, drying time of 45 min, and initial moisture content of 31.23 ± 0.26% (d.b.). Temperature measurements, relative humidity, pressure drop, and moisture content were carried out at 1, 2, 3, 4, 5, 10, 15, 25, 35, and 45 min. The obtained drying data were fitted to six mathematical drying kinetics models. The paddy moisture content was reduced to the final moisture content of 14.04 ± 0.75% (d.b.). In general, for all types of treatment capacity evaluated, the drying rate of a paddy utilizing an SFB dryer decreased as the drying time increased. Among examined models, the linear-plus-exponential model Its novelty that can describe paddy drying kinetics using SFB dryer. Its model considers the effect of drying capacity provided good fitting of the predicted moisture with the determination coefficient (R2) of 0.986676 and root mean square error (RMSE) of 0.039478. Besides, the best model constant and the coefficient was a polynomial type with a determination coefficient (R2) of 1.00, and the root means the square error is close to zero. The results indicate, capacity during the drying significantly affected the drying behavior of paddy using SFB dryer.