Performance Evaluation of the Desiccant Bed Solar Dryer

Abstract

Desiccant bed solar dryer is a solar dryer that has dehumidification system used for decreasing drying air humidity by install silica gel beds (SGB) for continuously drying process. Each SGB has width of 0.55 m, length of 0.95 m. and thickness of 0.01 m. The collector area is 2.5 m2 with 17 degree tilted angles. From the experiments can conclude that the top SGB has highest adsorption rate, average 0.073kg water/hr, the west SGB has lower adsorption rate, average 0.062kg water/hr and the east SGB has lowest adsorption rate, average 0.032kg water/hr. The parameters that effects to adsorption rate are air temperature and humidity ratio of humid air. The results shows that with-load test, the conditions that suitable for drying chili are 0.08kg/s mass flow rate and 60 oC drying temperature, drying chili 8kg from initial moisture content 82%wb to final moisture content 13%wb. The experiments were carried out by continuously operated and divided into two parts, with-dehumidification system and without-dehumidification system. The drying time of with-dehumidification system is shorter than without-dehumidification system 20.83%.