Experimental studies on drying characteristics of green chilies in a solar dryer

Abstract

Green and clean technology is the demand of today’s world. Solar dryer, for drying agriculture produce is one of the major applications of the solar energy. The flat plate air collector plays crucial role for drying the agricultural produce in solar dryer application. This research work, focuses on the design and development a solar collector for drying agriculture produces using waste aluminum cans of beverages. A solar air collector is designed and developed in the laboratory as per IS 1933, 2003 standard. A solar collector developed has been tested and an overall performance of the system is evaluated for three different mass flow rates (0.01 kg/s, 0.008 kg/s and 0.006 kg/s) for drying 15 kg of green chilies. The selective coating material made by mixing activated charcoal and black board paint is applied on the cylindrical curved surface of the tubes considering the critical radius of insulation. The inlet and outlet temperature of air has been recorded for different mass flow rate and the overall collector efficiency is calculated. Further, the moisture removal rate from green chilies is evaluated for every 30 minutes of time interval in a day. It is found that the efficiency is decrease with increase in mass flow rate. A maximum moisture removal rate of 88% is observed for a mass flow rate of 0.01 kg/s and the maximum efficiency of solar collector of 50.27%. is attained for a mass flow rate of 0.006 kg/s.