Performance Investigation of a Heat Recovery Assisted Solar Dryer for Mint Drying

Drying of agricultural products is a sophisticated process with high energy consumption. Energy needed for sustainable development, is one of the biggest challenges facing humanity. The performance of a heat recovery assisted solar dryer was evaluated in this study. Drying time, collector efficiency, energy consumption, solar fraction and energy recovery fraction were investigated at different drying air temperatures (45, 55 and 65 oC) and three levels of air flow rate (0.04, 0.06 and 0.08 kg/s). The results showed that collector efficiency decreased at higher drying temperatures and lower air flow rates. Increasing the air temperature from 45 to 65 oC reduced energy consumption by 25%. Meanwhile, the air temperature rise decreased solar fraction by 24% while improved energy recovery fraction by 20%.