MATHEMATICAL MODELLING AND SIMULATION OF FLUIDISED-BED DRYING, TEMPERING AND VENTILATION OF GRAINS

Abstract

The fluidized-bed grain dryer is now fully conunercialized and exported to several countries. Its potential is great especially for high moisture grains such as paddy, parboiled rice. maize and soybean. Its drying rate is very fast as compared to conventional grain dryers. Consequently, the size of drying unit is very compact relative to its capacity. Its energy consumption is relatively low While grain quality is maintained. In this paper, the research and development effort on fluidised bed grain drying is described, starting with an experimental batch dryer and culminating with a commercial continuous-flow dryer. A mathematical model of the fluidised bed grain drying system including a series of drying, tempering, ambient air ventilation and head-rice equation is derived. The model provides the useful infonnation about designing and operating condition for the drying system in order to optimize the drying capacity and quality, both of which show the contradict results.