DEVELOPMENT AND EVALUATION OF SOLAR CONCENTRATOR DRYER WITH ELECTRONIC MONITORING SYSTEM

Abstract

This research work focuses on the development and evaluation of a solar concentrator dryer with electronic monitoring system that can be used to dry agricultural products. It is designed in such a way that solar radiation is not incident directly on the agricultural product. The following materials were used to construct the solar concentrator dryer: wood, aluminium sheet, convex lenses, wire mesh, net, polythene and aluminium foil. The dimension of the solar concentrator dryer is 0.85 m x 0.69 m x 0.60 m and the area is 0.59 m2. The three main components of the dryer are: the drying chamber, the solar collector and the absorber. The drying products are placed on a detachable tray in the drying chamber, incident rays of light from the sun fall on the solar collector which converges the rays at a focal point thereby generating heat. The absorber then absorbs the incident solar radiation heating the air between it in the process. This increases the inlet temperature of the dryer and speeds up the drying process. The electronic monitoring system is used to monitor the temperature, moisture content and light intensity in the solar concentrator dryer and the open sun. The dryer was loaded with 300 g of sliced Plantain and 500 g of sliced Yam. The moisture content of sliced Yam and Plantain was reduced from 65.7% wet basis to 8.9% wet basis within 7 hours and 73.2% wet basis to 2.2% wet basis within 21 hours. This solar concentrator dryer preserved the high quality and good colour of the sliced Yam and Plantain.