Evaluation of Specific Energy Consumption During Solar Drying of Cylindrical Potato Samples for Different Thickness and Loading Densities

The knowledge of specific energy consumption (SEC) during drying of food product is necessary to estimate the potential energy saving possible with the use of solar dryer vis-à-vis fossil fuel operated dryers. In the present study, a laboratory model of forced convection mixed-mode solar dryer is designed and constructed. Drying experiments on cylindrical potato samples as a food product have been performed for a wide range of food product characteristic parameters namely, food product loading density (1.08 to 4.33 kg/m2) and sample thickness (5 to 18 mm). The experimental data of amount of moisture removal from food product, temperatures of hot and ambient air for each drying test condition has been utilised to compute specific energy consumption (SEC). Results of present study reveal that for each parameter investigated, SEC increases with the drying period. It is noticed that increase in loading density has reducing influence on SEC whereas the reverse trend is observed for food sample thickness. The study further indicates that increase in load density from 1.08 to 4.33 kg/m2 and decrease in sample thickness from 18 to 5 mm causes in reduction in SEC by 67.3% and 72.4% respectively.