INFLUENCE OF MIXING ON THE PRODUCT QUALITY IN PRECIPITATION

Precipitation of barium sulfate has been studied in a rectangular flat reactor with jet mixing, both experimentally and with Computational F luid Dynamics (CFD) modeling. The precipitation kinetics and mass bala nces were implemented in the CFD software (Fluent(R) version 4.25). Th e influence of the hydrodynamics on the quality of the precipitate has been Studied by changing the inlet velocity ratio while keeping the r esidence time and species concentration in the reactor constant. The C FD model was able to predict the influence of the inlet velocity ratio on the area mean particle size, the coefficient of variation of the p article size distribution, and the degree of conversion. Flow visualiz ation experiments show that the simulated flow pattern was in good agr eement with the experiments. A non-symmetric flow pattern was found, w hich was in agreement with the study of Murai e.a., 1989.