Performance of a Sand Medium Dryer for Shelled Corn
ABSTRACT A new type of recirculating solid medium grain dryer with internal helical flighting using sand as a heat transfer medium was tested for its potential in agriculture. An average moisture removal of 3.4% on the dry basis was achieved from corn grain when the sand temperature of the dryer was 150 °C with residence time ranging between 18 and 29 s and grain mass flow rate between 5 and 12 kg/min. Calculated drying efficiency ranged from 25% to 39% and fuel efficiency ranged from 60% to 95% when drying corn from an initial moisture content of 36% d.b. Correlations between the moisture removal, fuel efficiency and dryer operating conditions were established. Information gathered from this study was used to improve the design of the drying unit.