Energy and exergy analysis of banana drying process with the hybrid dryer

Utilization of energy in the drying industry makes drying as one of the most energy intensive operations. In this research, energy and exergy analysis of drying of banana was performed by the hybrid dryer. The experiments were carried out in air velocities of 1, 1.5 and 2 m/s and air tempreatures of 60, 70 and 80℃ with thickness of 5 millimeter. Data was analyzed by complete randomized complete block design with factorial experiment. With increasing time of drying, weight of banana, moisture content, energy utilization, heat of evaporation, outlet exergy and exergy efficiency decreased while exergy loss increased. With increasing air temperature and air velocity energy utilization, heat of evaporation, outlet exergy and exergy loss increased while exergy efficiency decreased. The results of energy and exergy analysis showed that the maximum of utilization energy and exergy loss were 0.91 and 0.41 kJ/s, for air temperature of 80℃ and air velocity of 2 m/s, respectively, while, the minimum of utilization energy and exergy loss were 0.10 and 0.02 kJ/s, for air temperature of 60℃ and air velocity of 1 m/s, respectively. In process of drying, the maximum of exergy efficiency was 91% for air temperature of 60℃ and air velocity of 1 m/s, while, the minimum of exergy efficiency was 0.3% for air temperature of 80℃ and air velocity of 2 m/s.