Absorber Thickness Effect on The Effectiveness of Solar Collectors to Production Hot Air For Drying

Abstract

One way to increase the drying rate using a solar collector is to increase the air temperature of the collector and the time of circulation of hot air delivered to the drying chamber. The optimization of heat absorber by utilizing solar energy has been shown to be strongly influence by fluid flow characteristics in the collector channel. This study examined the sharp turning channel on the air passage of a solar collector. Collector size used was 305 cm x 80 cm and had 10 sharp turning channel baffles. Solar radiation absorbent material used in this collector test is iron sand with three thickness variations, namely 3, 6, and 9 cm. The measurement results show that the air temperature that can be produced by the collector with a thickness of 3 cm absorber reaches 85 degree Celsius with an effective drying time of 8 hours and the final air temperature testing on the collector out side still reaches about 40 degree Celsius at air temperature of 32 degree Celsius. At a thickness of 6 cm absorber, the air temperature inside the collector was about 83 degrees and the duration of 10 hours of drying time, with the collector-out air temperature around 39 degree Celsius at the air temperature of 30 degree Celsius. In contrast to the 9 cm thickness of the absorber, the drying air temperature was only 81 degree Celsius and the drying time was 12 hours and the final air temperature measurement was 40 degree Celsius at the ambient temperature was 27 degree Celsius. This result can be seen as the effect of thick collector absorber on solar thermal energy that can also be absorbed by absorber solar collector.