Abstract
This study evaluates the drying behavior, kinetics, morphology, efficiency, and heat and mass transfer phenomena of three differently shaped samples. A refined model was used to validate experimental results. The maximum recorded solar irradiance and ambient air temperature were 775 W/m2 and 40.5°C, respectively, at 14:00. At this peak time, crop surface temperatures were 55.2°C, 63.2°C, and 70.1°C for Sample-I, Sample-II, and Sample-III, respectively, due to higher solar irradiance. The maximum drying rate for Sample-I was 0.017 g/g db.hr at 11:00, gradually decreasing thereafter. For Sample-II and Sample-III, peak drying rates were 0.012 and 0.017 g/g db.hr at 11:00, respectively. The highest drying efficiency of 26% was achieved in Case-I, with 24.5% and 22.5% observed in Case-II and Case-III. The Prakash and Kumar model, with root mean square errors of 0.0219, 0.01487, and 0.01831, effectively described the thin-layer drying kinetics. The developed drying system demonstrates superior cost-effectiveness, featuring low operating costs and a payback period of 1.25 years, outperforming other market options. Scanning electron microscopy (SEM) analysis has also been done to examine the surface morphology of the solar dried food samples and showed brittle walls due to moisture loss, as indicated by SEM testing.
