SOLAR DRYER FOR FOOD PRESERVATION

Abstract

Drying is one of the most significant preservation techniques for preservation of fruits and vegetable but also an energy consuming process. Current deficiencies of fossil fuels have encouraged the world to shift focus towards the renewable energy. Solar energy is one of the most important types of renewable energy and it is more desirable because it is abundant, infinite, and environment friendly. The solar drying system uses energy from sun to heat up air and to dry any fruits vegetables loaded and helps in preservation of fruits and vegetables. According to the boundaries of the natural sun drying such as exposure to straight sunlight, liability to pests, absence of proper monitoring, and the increased cost of the mechanical dryers, a solar dryer was therefore established to cater for these limitations. This project presents the design and construction of a passive solar dryer, the dryer consists of solar air collector and a drying chamber containing rack of 2 trays both being integrated together. The air enters through inlet, then heated in solar collector after that it is passed through drying chamber when it dries the crop. The temperature of dryer can be controlled with the help of fans installed on the inlet and outlet, and an optimum temperature range can be maintained which is in around 45-55 degrees centigrade. It was observed that the use of this type of solar dryer reduced the drying time considerably and basically provides better product quality compared with conventional drying method. The method of drying, parameters affecting it, types of dryers and the relation of temperature, moisture contents with rate of drying are also studied.