Performance evaluation of solar crop dryer integrated with solar air heater

The aim of the experimental study is to develop a crop dryer with integrated solar air heater for domestic applications. Indirect drying is better than open sun drying in terms of the quality of the product achieved. The apparatus should also be economically viable for small scale farmers. The above evaluation is to be done by drying products like potatoes, tomatoes, onion, coriander and green chilies. The setup consists of collector plate of 1.3×1.6 m made of GI sheet and V-corrugated grooves with double glass cover. The drying chamber is 0.6×0.3×0.6 m (l×b×h) and has three layers of trays for keeping food items. The collector plate is inclined at 32° for year round application. The key parameters for suitable drying are temperature, humidity and flow rate levels. These parameters determine the moisture removal rates which are important to evaluate the appropriate drying duration for a particular food product.