(362a) Motion of a Large Solid in Bubbling Fluidized Bed

In the practical applications of fluidized bed such as gasification, combustion, separation and granulation, the size of solid materials is not uniform and large solids are coexisting with small emulsion solids.  The large size-difference induces characteristic motion of solids in the beds and results in segregation phenomena.  It is difficult to reproduce the behavior of these systems by the existing numerical models and a new numerical model is proposed in the present study.  The model is based on the DEM-CFD mesoscopic model and extended by introducing an idea appeared in Volume penalization method (Kolomensky & Schneider 2009).In the present study, the behavior of single large solid in bubbling fluidized beds is investigated by using the proposed model. Forces working on the large solid during fluidization can be decomposed into pressure gradient, viscous and contact forces. In the study, the relations between these forces and the motion of the large solid are discussed in detail.