Drying behaviours of bittim (Pistacia terebinthus) in a fixed bed drying system

In this study, drying behaviours of the outer shell peeled Bittim (Pistacia terebinthus) with initial moisture content of 42.2% (dry basis (d.b)) was investigated in a novel fixed bed drying system. The drying experiments were performed at different temperatures (40 °C, 60 °C and 80 °C), ai r velocities (0.5 m/s and 1 m/s) and weights (30 g and 40 g). A constant rate period was not observed in the drying of bittims; all the drying process occurred in falling rate period. Two models in literature were selected to fit the experimental data. The fit quality of models was evaluated using the coefficient of determination (R2), sum square error (SSE) and root mean square error (RMSE). Page model has a good agreement with the experimental data and gave the best results for bittims in a fixed bed system.