Design and Performance Evaluation of a Solar Dryer

Abstract

Abstract One of the ways to combat food insecurity as world population rises is the reduction of food losses. Drying is one of the oldest methods of food preservation and hence reduces food losses. Solar drying uses energy from the sun and an absorber material to carry out drying of produce. In this project, a solar dryer was designed, constructed and its performance was evaluated. The dryer has overall dimensions of 1000mm by 410mm by 700mm. The inner part of the dryer compartment was lagged with aluminum foil to act as an insulator. The solar collector made of galvanized sheet and the glass on top of it have an area of 800mm by 380mm. Fresh scotch bonnet pepper was used as the produce of choice. The pepper was dried in 2 experiments for 3 weeks each. 200g of pepper was used and weighed to measure weight loss periodically. Temperature and humidity of the drying chamber and the surrounding were measured with data loggers throughout the periods of the experiments. The results showed that the ambient temperature during the experiments was higher than the temperature of the drying chamber in the early hours of the morning between 4am and 10am. During every other period, the temperature in the drying chambers was higher than the ambient temperature. An average moisture content of 81.3% w.b. was removed from the pepper during the experiments. The average efficiency of the dryer was 28.4%.