PERFORMANCE EVALUATION OF AN INDIRECT NATURAL CONVECTION SOLAR DRYER FOR OKRA DRYING IN ABECHE, CHAD

Abstract

This study presents the design, construction, and performance evaluation of an indirect natural-convection solar dryer used for drying okra under the Sahelian climatic conditions of Abeche, Chad. Post-harvest losses of vegetables remain a major challenge in the region due to inadequate preservation techniques. Experimental drying tests were conducted to monitor temperature, relative humidity, moisture content, and drying time. The results show that the solar dryer achieved higher drying temperatures than ambient conditions, leading to a significant reduction in moisture content from fresh okra to safe storage levels within a reduced drying time compared to open sun drying. The developed system demonstrates an efficient, low-cost, and environmentally friendly solution suitable for rural areas in arid regions.