Numerical Study of the Agglomerates Dispersion Behavior in Shear and Elongational Flow Fields in Viscous Media Using Population Balance Modeling (PBM)

Abstract

In particulate systems, formation and fragmentation of agglomerates/aggregates are the major phenomena in the case of dynamic processing of suspensions. In the present work, the dispersion of the agglomerates was studied in shear flow fields (SFF) and elongational flow fields (EFF) using population balance Method. Since there is no direct data on EFF, predicted data obtained through Discrete Element Method was used to obtain a proper break-up kernel for EFF. So, a power-law break-up kernel was proposed for EFF and an exponential one was considered for SFF. It was shown that increasing the intensity of deformation rate in both flow fields, sped upthe break-up process and the mean aggregates/agglomerates sizes shift toward the finer flocs. This effect was more pronounced for SFF showing more sensitivity to the deformation rate. It was concluded that because of the ability of EFF in agglomerate break-up, it would break the agglomerates even in lower deformation rate. Since agglomerate could rotate in SFF, the final agglomerate size would show more dependency on the deformation rate. Results depicted that EFF leads to broader agglomerate size distribution in comparison with SFF. The final fragment size showed more dependency to the agglomerates structure in SFF compared to EFF.