Infrared / Convection Dryer Utilization for Drying of Pomegranate Peels

Abstract

The aim of this study investigated the effects of some various variables on drying a thin layer of pomegranate peels exposed to infrared and hot air. Three different levels of infrared power, namely: 150, 200 and 250 W and three different exposure distance "the distance between infrared heater and samples" of dying are 10, 15 and 20 cm with air temperature 40 o C and air velocity 1.5 m/s were studied. Moisture ratio and drying time affected by infrared power and exposure distance, compatibility of experimental data to some drying models, effective diffusivity "Deff", Specific energy consumption "SEC "and rehydration were also studied. The results show that the higher the infrared power and the lower exposure distance the lower the moisture ratio and the total drying time reduced, and it was found that the least drying time was 30 minutes with infrared power 250 W and exposure distance 10cm. Lewis model was best fitness to the experimental data with average R 2 0.9972. The maximum values of Deff were recorded at highest infrared power 250 W. The rehydration ratios ranged between 0.80 to 2.42 under various dryin conditions.