DEVELOPMENT OF A TRAY DRYER FOR FRUITS AND VEGETABLES USING ZIG-ZAG AIR FLOW CONFIGURATION
Post harvest losses in fruits and vegetables in developing countries like Nigeria is high due to poor storage and processing facilities. The use of cabinet dryer for dehydration of fruits and vegetables to improve their shelf life has a drawback of non-uniformity in drying along the length of trays. Hence an effort was made to solve this problem by using a zigzag air flow pattern configuration. A cabinet dryer of capacity21kg/batch was designed and developed. The dryer was tested with okra slices using zigzag air flow pattern configuration. At an air flow rate of 8.8m3/s and 600c it took about 9 hours to reduce the moisture content from 79.55% (w.b) to 6.03%(w.b). Results obtained showed that drying of the okra slices took place in the falling rate period. The drying efficiency of the dryer was found to be 70%.