Numerical investigation of air flow in a vertically paddy bed dryer using computational fluid dynamics

This research focuses on the numerical investigation of air flow in a vertically paddy bed dryer using computational fluid dynamics - CFD. In this study, the Tubtim Chumphae paddy and perforated plates were assumed to be porous media and their properties were characterized experimentally in a 0.05 m × 0.05 m × 1 m duct. In this paper, the obtained porosity and permeability were applied to a numerical model, the air flow through a 100 kg paddy, stored in a vertical bed dryer. The results from the simulation and experiment agreed well with each other via the calibration process. The pressure drop across the dryer was found to increase when the inlet velocity gained from 0.025 to 0.1 m/s with an increment of 0.025 m/s. In this study, the results showed that air flow was controlled past the paddy with the deviation of less than 2.82% to achieve a high rice quality after the drying process. Because this drying technique used low temperature air and had low energy consumption, therefore, it is found to be one of the promising techniques and truly benefits the farmer in the future. (paper)