The Dehydrative Capacity of Solar Rice Dryer for Rural Application in Nigeria

Abstract

A detailed method for determining the dehydrative capacity of solar dryer is presented in this paper. A solar drying system working on the principles of natural heat flow was developed using mainly inexpensive locally available materials to make it relatively affordable. The dryer was evaluated by the dehydrating temperature and relative humidity attained, rate of moisture removal from the food item and its overall dehydrative capacity. The results obtained during the period of test revealed that the dehydrating temperature inside the drying chamber was higher than the ambient temperature by an average of 64% during most hours of the daylight. The dryer was able to reduce the moisture content of the wet rice from 33.0% (dry basis) to 1.4% (dry basis) in 13 hours of effective dehydration time. The system overall dehydrative capacity and drying efficiency during the test period were 0.5 kg/kg.h of atmospheric air and 52.2%, respectively