Design And Development Of Solar Seed Dryer

Abstract

Solar energy is the most promising of the renewable energy sources in view of its apparent limitless potential. Direct solar energy has been applied to grain drying for years. The sun and wind dry crops in the field, stack or windrow. Artificial drying has supplemented this process to increase the harvest rate during inclement weather or to minimize field losses. This article investigates solar grain drying as one alternative. Radiant energy from the sun reaching the earth surface is known as shortwave radiation, solar radiation, solar energy or isolation. The total radiation may be direct from the sun; diffuse, scattered by the atmosphere or reflected, from adjacent surfaces. A small scale village level solar dryer for tomato was developed under Yola weather at latitude 9°14′ N and longitude 12°26′ E using locally available materials and the performance was evaluated. On the similar approach we manufactured seed dryer which is also more useful for drying the seeds, crops i.e. maize, beans etc. The essence of the dryer was to achieve the effective method of seed preservation and eliminate the drudgery and product deterioration associated with traditional methods of open sun drying of seed. This is in view of alleviating the weather limitation experienced by farmers in crop drying especially for tomatoes. The solar dryer consists of tray, reflective walls and glass roof, a preheating air absorber plate, inner panels for removal of moisture and chimney through which air stream passes across the dryer. Evaluation of the dryer showed a raised temperature of about 470 attainable in the drying chamber. The dryer temperature and drying rate was found to be higher than the natural open sun drying method. The results showed a considerable advantage of solar dryer over the traditional open sun drying method in term of drying rate and less risk for spoilage.