Performance analysis of drying of carrot slices in a semi-industrial continuous band dryer

This paper presents the energy and exergy analysis of drying process in a semi-industrial continuous band dryer. Experiments were performed on thin layer drying of carrot slices with thickness of 5 mm, at air temperatures of 50, 60 and 70 degrees C, drying air mass flow rates of 0.61, 1.22 and 1.83 kg/s and feeding rates of 2.98 x 10(-4), 3.48 x 10(-4) and 4.16 x 10(-4) kg/s. The effects of drying variables were evaluated on weight loss of dried products, energy utilization, energy utilization ratio, exergy loss and exergy efficiency. An amount of 250 g of fresh material was used on each band for drying experiments and the weight loss of dried samples were found to be in the range of 51.6-84.4% of initial weight. The energy utilization and energy utilization ratio varied between 3.78-25.57 kJ/s and 0.1554-0.3752, respectively. The exergy loss and exergy efficiency were found to be in the range of 0.6677-14.1577 kJ/s and 0.5527-0.9329, respectively. (C) 2008 Elsevier Ltd. All rights reserved.