Development of a low-cost wind-powered active solar dryer integrated with glycerol as thermal storage

Abstract

The paper presents an active mix-mode wind-powered fan solar dryer (AWPFS) with a passive mix-mode non-wind-powered solar dryer (PNWPS) evaluated with pre-treated potato slices. The two dryers were tested with and without glycerol as thermal energy storage. The objective was to present a non-electricity powered active solar dryer using only clean energy sources. Evaluation of the dryer took place at ambient temperature range of 24–50 °C and humidity of 10–52%. The results indicate that drying with AWPFS integrated with glycerol showed shorter drying time than drying with AWPFS only or PNWPS. Dipping the potato in a salt solution and blanching for 30 s before drying quickened the drying rate of the potato compared to other treatments. The energy consumed for drying ranged from 4.10 to 4.98 MJ, while the specific energy consumption ranged from 2.846 to 3.686 kWh/kg. The drying efficiencies ranged from 25.031% to 31.5%, while the exergy efficiency ranged from 14.5 to 80.9%. With low electricity penetration density across Africa, this dryer with naturally powered fan will help crop processors dry their product faster and about 15.3–290.4 $/year could be saved at 10–100% rate of usage