Energy Consumption of Yam Slice Drying in an Exhaust Gas Waste Heat Recovery Hot AIr Tray Dryer

Evaluation of the energy consumption during the thin-layer drying of yam slices in an exhaust gas waste heat recovery dryer is presented. The study took cognizance of some energy parameters such as the electric power consumption, thermal energy consumption and specific energy consumption during the drying process. Blanched white yam samples of different thicknesses were subjected to varying conditions of drying air temperatures and velocities of 55, 65, and 75C; and 1.0, 1.5, and 2.0 m/s. The minimum value of electric power consumption (44.63 W-hr) was achieved at the drying air temperature and velocity of 75 and 1.0 m/s, and slice thickness of 1.0 cm; whereas a maximum value of 157.70 W-hr was obtained at the drying air temperature and velocity of 55 , 2.0 m/s, and 1.0 cm slice thickness, respectively. The specific energy consumption values were in the range of 40.25 to 97.80, 52.33 to 108.79 and 58.77 to 124.16 kW-hr/kg, respectively for 1.0, 1.5 and 2.0 cm slice thicknesses. The results obtained revealed that the drying air temperature and velocity had an appreciable influence on the values of the energy consumption parameters of the dryer for the yam slice drying. It was observed that for all the experimental treatments, the higher the slice thickness of the yam samples, the higher the obtained energy consumption values.