Simulation of fine particle formation by precipitation using computationalfluid dynamics

The Lt-environment generalized micromixing (4-EGM) model is applied to desc ribe turbulent mixing and precipitation of barium sulfate in a tubular reac tor. The model is implemented in the commercial computational fluid dynamic s (CFD) software Fluent. The CFD code is first used to solve for the hydrod ynamic fields (velocity, turbulence kinetic energy, turbulent energy dissip ation). The species concentrations and moments of the crystal size distribu tion (CSD) are then computed using user-defined transport equations. CFD si mulations are performed for the tubular reactor used in an earlier experime ntal study of barium sulfate precipitation. The 4-EGM CFD results are shown to compare favourably to CFD results found using the presumed beta PDF mod el. The latter has previously been shown to yield good agreement with exper imental data for the mean crystal size at the outlet of the tubular reactor .