Experimentally-assessed multi-phase CFD modeling of segregating gas–solid fluidized beds

Abstract

Eulerian–Eulerian modeling is widely applied in simulations of multi-phase flows in fluidized beds. However, the validity of this model is questionable, especially with the limitation of gas–solid drag closures. In this study, CFD simulations were performed to investigate the validity of the numerical model for segregating fluidized bed. The numerical model was tested with experimental data from the literature to select the most appropriate gas–solid drag model. It was found that the Gidaspow drag model is generally better than the Syamlal–O’Brien, the BVK, and the Di Felice models. However, all the drag models showed poor agreement with experimental data of size segregating systems. Also, all the investigated gas–solid drag models mispredicted the minimum fluidization velocity of various fluidized bed systems. The Gidaspow and Di Felice models had an acceptable error, while the BVK and the SB always under-predicted the minimum fluidization velocity with high error. A new correlation was proposed to correct the computational superficial velocity to mitigate the effect of the error of fluidization velocity prediction by the Wen-Yu gas–solid drag model.