Mixing, reaction and precipitation: An interplay in continuous crystallizers with unpremixed feeds

A process involving elementary chemical reaction between two reactant species and subsequent precipitation of product in a continuous crystallizer with unpremixed feeds at the entry is modelled by the three- and four-environment models. The sensitivity of these models to Damkohler number and dimensionless micromixing parameter is explored. The computationally efficient environment models appear to characterize satisfactorily the micromixing effects in a continuous reactive precipitator, while the IEM model description in a continuous MSMPR (mixed suspension mixed product removal) crystallizer is better suited to a nearly segregated system. Generally, the micromixing effects are much more important when the reactants enter separately than when they are initially premixed just before entry. Both reaction and crystallization performance are significantly influenced by the feed conditions.