Experimental Investigation on Performance of Domestic Type Solar Crop Dryer Under Free Convection

Drying of food items/crops under the sun (open conditions) is presumably one of the conscious and purposeful technological activity undertaken since long. Drying of products using solar crop dryer is very much advantageous over drying done in open conditions and mechanized form of drying. Many investigations on drying of crops/food products by using the solar crop dryers with different modifications have been reported in the literature. In the same direction, it has been thought to modify the dryer in which the wiremesh type of tray is used as an alternative to perforated trays and reflector plate was also attached for having more solar radiation on to the solar crop dryer. The present solar crop dryer is fabricated in such a way that it can be used under free and forced convection conditions. However, the present experimental investigation on performance of domestic type solar crop dryer has been carried out only under free convection for drying ginger and green chilli crops. Maximum average temperature of 54.8oC was recorded inside the solar crop dryer. Moisture removal from ginger and green chilli with drying in solar crop dryer was found much higher than that found with drying of the crops in open conditions. Maximum moisture removal of 23.7% was found in the case of ginger when reflector was used and shading plate was not used. Maximum thermal efficiency of solar crop dryer has been found as 14.4% for drying of ginger crop.