Mathematical Modelling of Banana Slices in Natural Convection Indirect Solar Dryer

The energy for drying agricultural products comes from various sources such as electricity, natural gas, biomass and fossil fuels. The practice of solar energy utilization in the agricultural sector has a potential scope to minimize the cost of operation, replace the conventional drying methods and save environment by reducing carbon foot print. In the present study, heat pipe assisted natural convection indirect solar dryer (HNISD) was used to determine the drying behaviour with respect to thickness in banana slices with three different thickness namely 2,4 and 6mm. The drying time taken for 2 and 4 mm thick slices was 12 hours whereas the slices with 6 mm thickness took 13 h of drying time. The experimental data was best fit with the Midilli-kucuk model for HNISD. For open sun drying Two-term model was found to be best model to explain the drying characteristics of banana slices.