Design of a Photovoltaic Powered Forced Convection Solar Dryer in NEH Region of India

Abstract

A low cost photovoltaic powered forced convection solar dryer was developed and evaluated for drying of Chilli in the conditions of NEH region of India. The PV powered forced convection solar dryer consists of solar PV module of area (280×230) mm² connected with drying chamber. The solar panel is tilted to an angle of 45° with respect to horizontal. It was connected to the exhaust fan provided at the opposite wall of the dryer with the help of electric wire. The drying chamber was made up of M.S. angle, G.I. sheet and glazing material with the frame size of (700×700) mm², opposite wall size of (700×700) mm² and front side size of (890×700) mm² with the inclination of 45°. The two drying trays were contained inside the drying chamber which is made up of aluminium angle, aluminium strip and steel wire mess. The lower and upper tray was fitted at the height of 150 mm and 350 mm from the base of the dryer. The size of lower and upper tray was (680×490) mm² and (680×270) mm². Air inlet is provided in the one fourth area of the base with the diameter of 600 mm. The drying chamber is insulated with thermocole of 10 mm thickness. At the one side of the dryer an insulated door is provided to facilitate the loading and unloading of the trays. The dryer was capable of holding about 6 kg of chillies per batch. Average air temperature attained in the solar dryer was about 40^oC higher than the ambient temperature. Drying of chilli in a PV powered forced convection solar dryer reduces the moisture content from around 80.2% (wet basis) to the final moisture content about 10.00% in 32 h.