Experimental Evaluation of Drying Kinetics and Thermal Performance of Potato Chips Using Hybrid and Conventional Solar Drying Systems

Abstract The present study involves an experimental examination of drying kinetics and thermal performance of the potato slices in three solar drying systems, namely, hybrid greenhouse solar drying (H-GSD), greenhouse solar drying (GSD), and open sun drying (OSD). The objectives of the investigation were to identify the best drying conditions and determine the moisture content, rate of drying, moisture ratio, effective moisture diffusivity (EMD), convective heat transfer coefficient (CHTC), and maximum temperature profiles. It was shown that H-GSD had a greater drying efficiency with a moisture reduction of 84–7.5% (wet basis) in 10 h. H-GSD had a higher drying rate of 20.08 g water/g solid/h with a corresponding moisture ratio of 0.44, which was superior to that of GSD (0.56) and OSD (0.75). EMD values were 1.25 × 10−07 to 2.52 × 10−07 m/s, CHTC was 3.02 × 10−04 in H-GSD, showing the forced convection was increasing mass transfer. In H-GSD, drying cabin temperature went as high as 46.75 °C in the loaded condition, which was considerably greater than the ambient conditions. A good fit of the drying kinetics in all systems was obtained with the best fit used by Prakash and Kumar, with R2 values of above 0.99. These results confirm the efficiency of the solar drying systems that involve the use of heat exchangers in enhancing the drying process and the quality of the products. The results of this study contribute to the achievement of the sustainable and energy-saving drying technology to be used in agriculture, especially in the rural and semi-urban conditions.