A system dynamic modeling to evaluate fluidized bed dryers under tempering and recirculation strategies

Grain drying control strategies aim for a rational energy use and a final product with low breakage levels. However, an experimental approach may be prohibitive due to the costs, scale, and theoretical complexity of this operation. The simulation environment is suitable to design equipment’s and plan operations strategies with low cost and high certainty. This work utilized system dynamics modelling to quantify the percentage of product breakage during drying in fluidized bed dryers under recirculation and tempering strategies. A sensitivity analysis of the model’s input parameters including different fractions of recirculation was performed, showing their effects on drying and post-drying product quality. Finally, we present optimizations from different objectives of drying operations. The recirculation strategy worked as an attenuator to the drying rates and combined with tempering strategy reached a minimum breakage level.