Some design aspects of the assisted solar drying system with double-pass finned solar collectors

-The drying of material means removal of the moisture from the interior of the material to the surface and then followed by the removal of the moisture from the surface of the drying material. Open air sun-drying require large space and depend on the weather, so much of post harvest looses and quality degradation. Using solar drying system may reduce the lost. The system consists of solar air heating collector array, blower, auxiliary heater, and drying chamber. The solar air heating collector with high efficiency is needed for this system. The double-pass finned collector is used, its array in series. The collector size is 120 cm in width and 480 cm in length. The outlet temperature from collector is about of 85 C on solar radiation of about 650 W/m and air flow rate of about 0.08 kg/s. This solar drying system may dry 100 kg wet oil palm front from 70% to 15% moisture content in 8 hours.