Experimental comparison of solar drying based on evacuated tube collector with desiccant drying for dehydrating potato and ginger

Abstract

AbstractIn this article, a comparative study of different drying techniques, namely, open sun drying (OSD), desiccant drying, solar drying (SD), and solar drying with desiccant (SDWD) was done for drying potato and ginger. The thermal efficiency and air temperature differences of the solar dryer based on evacuated tube collectors were also examined. The average efficiency of the solar dryer was 29.01%. Average drying rates of OSD, desiccant drying, SD, and SDWD bed are 0.435, 0.435, 0.59, and 0.635 g/min. The moisture content of the potato was reduced from 79.6% to 32.9% by OSD, 32.6% by desiccant drying, 9.6% by SD, and 6.9% by SDWD. The moisture content of the ginger was reduced from its initial value of 82.3%–25.3% by OSD, 25% by desiccant drying, 10.1% by SD, and 3.2% by SDWD. SD assisted with a desiccant bed proved to be the best method for drying vegetables. Drying with desiccants is not feasible for drying in winter and spring seasons of the Indian climate.