ANALYSIS OF DIFFERENT TECHNIQUES FOR IMPROVING PERFORMANCE OF FLAT PLATE SOLAR COLLECTORS FOR FRUITS DRYING

Abstract

Fruits drying had become a broader technology in fruits and vegetables value addition.The technology is reported to be a promising way of drying without incurring higher costbut its adaptation has not been feasible in rural areas. Solar dryers have been developedbut its poor performance limits its applicability. In this study, several techniques formodifications of traditional solar collector were addressed. It was observed that, varyingcollector designs in different techniques, a range of collector performances can bearchived. The research shows that, collector efficiency can be improved by 9.6% whenemploying double duct counter flow compared to conventional collectors. Likewise,performance difference between conventional collectors and studied models were found tobe 8%, 7.2%, 6.1% and 5.2% for model parked with charcoal, 5 mm wire mesh, 4 mmglass thickness and 8 baffles respectively. This study shows that, double duct counter flowsystem is the best option for improving the performance of the collectors, followed bycharcoal and wire mesh. On the hand, using 4 mm glass thickness gave improvedperformance, however, it is recommended for collector size not exceeding 2 m in length.