Thermodynamic analysis of drying process in a diagonal-batch dryer developed for batch uniformity using potato slices

Optimized air distribution is important for the energy consumption in a batch drying process. Energy and exergy analyses for an innovative diagonal-batch dryer were performed using potato slices of 5 mm and 8 mm thicknesses at 55 °C and 65 °C. The exergetic efficiency, improvement potential rate (IP) and exergetic factor (f) were taken as performance parameters. The main component for improving the system efficiency was found to be the fan-heater combination, possessing low exergy efficiency, high IP and high f values. The energy utilization, energy utilization ratio, exergy losses and exergy efficiency varied between 1.82 and 12.52 kJ/s, 0.04-0.59, 1.3-4.89 kJ/kg and 0.41-0.94, respectively for potato slices. The specific evaporation energy and specific product energy were found to be in the range of 4.78-6.13 MJ/kg and 16.24-20.63 MJ/kg respectively. The outcomes of the analysis will provide insights into the optimization of a batch dryer for the maximum retention of quality parameters and energy saving.