SOLAR DRYING OF GALANGAL SLICES (ALPINIA GALANGAL (LINN.) SWARTZ.) USING HOUSEHOLD SOLAR DRYER
Keywords:
Experimental performance, galangal, polycarbonate, solar dryer, solar dryingAbstract
This paper presents a method for drying galangal slices using hot air from a household solar dryer. The solar dryer was developed and installed at the Division of Physics, Faculty of Science and Technology, Thepsatri Rajabhat University, Lopburi, Thailand (14.80°N, 100.62°E). The dryer has a parabolic shape to facilitate the construction. A polycarbonate plate covers the solar collector with an area of 0.901.90 m2. The polycarbonate cover is used to reduce heat loss while allowing the incident solar radiation to be transmitted into the solar dryer. Two direct current 12-Volt fans powered by 1 10-Watt photovoltaic module ventilate the dryer. To investigate the experimental performances of the solar dryer for drying galangal slices, 6 full-scale experimental runs were conducted. For each batch, between 5-6 kg of galangal slices were dried. The drying air temperature varied between 30C to 55C from 8:00 am to 6:00 pm during drying. The drying time in the solar greenhouse dryer was 1 day to dry the galangal from an initial moisture content of 89% (wb) to a final moisture content of 12% (wb), compared to 2-3 days with natural sun-drying under similar conditions. The payback period of the dryer is estimated to be 0.9 years. The galangal dried in this dryer was completely protected from insects, animals, and rain, and a good quality of the galangal was obtained.
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