Performance Evaluation of a Solar Tunnel Dryer For Around The Year Use

Abstract

This study was done to evaluate the performance of a walk-in type solar tunnel dryer for around the year use. In the present study, the performance of solar tunnel dryer was evaluated at no load and at full load conditions. Full loading was done with garlic, chili, fenugreek and aonla candy according to their seasonal availability in Hisar, India. At no load condition, performance was evaluated during three seasons i.e summer, winter, and autumn. During full load, the dryer reduces the moisture content of garlic from 65% (w.b.) to about 8.5% (w.b.) in 8 days, chilli from 77%(w.b.) to 7% (w.b.) in 7 days, fenugreek from 86% (w.b.) to 7.2% (w.b.) in 5 days and aonla candy from 44% (w.b.) to a safe moisture content of 16%(w.b.).The thermal efficiency of the dryer was also measured and was found between 8.89% to 17.63%. A temperature of 15-30 ºC higher than the atmospheric temperature was recorded inside the dryer. Products dried were hygienic and their sensory evaluation showed that they were of good quality and highly acceptable.