Investigation of Thermal Efficiency of the Double Pass Oscillating Bed Solar Dryer

Solar energy is abundant and more useful for various applications like power productions, battery charging and drying food product etc. The aim of the project is to develop a solar dryer for drying of agricultural produce like paddy, sunflower seeds and maize for improve their quality. In olden days open Sun drying is the most common method used to preserve agricultural produce in most countries. But it has some problem like unprotected from rain, wind-borne dirt and dust, infestation by insects etc. Some of the problems associated with open-air sun drying can be solved in this new solar dryer. A typical solar dryer comprises two major components viz, a solar collector and a drying chamber. In the present work, a double-pass solar flat plate collector is used to produce hot air and this hot air is supply to two pass oscillating-bed drying chamber through centrifugal blower for drying of agricultural produce. Many Drying test has been conducted using this solar dryer. The drying rate, drying efficiency and pick up efficiency are calculated. From the result, some suggestions are given to improve the efficiency of this solar dryer.