Modeling heterogeneous downward dense gas-particle flows



A novel approach is proposed to model heterogeneous downward dense gas-particle flows. The homogeneous behavior of the flow is described by the mass and momentum transport equations of the gas and particulate phases solved using a mono-dimension finite volume method on staggered grids. The heterogeneous features of the flow are predicted simultaneously using the bubble-emulsion formalism. The gas compressibility is taken into consideration. The model is supplemented with a new correlation to account for the wall-particle frictional effects. The predictions are compared with the vertical profiles of pressure and the amount of gas that flows up and down two standpipes and a cyclone dipleg of an industrial fluid catalytic cracking unit and of a cold small-scale circulating fluidized bed. The trends are well predicted. The model gives further information and is thus an innovative starting point for downward dense gas-particle flow hydrodynamics investigation. © 2009 American Institute of Chemical Engineers AIChE J, 2010