A batch drying system was developed by the Faculty of
Engineering, Mahasarakham University, Thailand. The system
consists of a vertical cylinder shape drying chamber with a
dimension of 15 cm in diameter and 60 cm in height, 18 kW
electrical heater and a backward curve fan driven by 2 kW
electrical motor as shown in Fig. 1 and 2. Drying-air
temperature was controlled by a proportional integral
derivative controller with an accuracy of +1o
C. A frequency
inverter regulated airflow rate.