Comparative Performance Assessment of a Solar Hybrid Dryer with Traditional Drying Techniques

Abstract

Among all the drying techniques, solar drying is one of the most ancient and simplest forms of drying known to mankind, which used even today especially in developing countries like India. However, drying the products directly under the open sun has many drawbacks such as rain, insect infestation, decolorization. Such problems can be eliminated by using dryers run by solar energy. Thus, there is a need to make the solar dryers more efficient and cheaper. The study presented here describes a comparison of solar dryer with open sun drying. A solar hybrid dryer is fabricated for experimental purpose with the provision of operating in three modes—indirect solar mode, electric mode and hybrid mode. The experiment was conducted as active system by the using of blower. The hot air generated is supplied by the blower to the drying cabinet. An air-mixing cabinet is also introduced for proper mixing of hot air from the two sources (in case of hybrid dryer). The temperature profile of the dryer is studied and compared with normal open sun drying. The results show better performance as approximately 35, 15 and 25% more moisture are removed in electric, indirect solar and hybrid mode compared to open sun drying.