Modelling of crystal growth of KDP in a 100 dm3 suspension crystallizer using combination of CFD and multiblock model

In this study a combination of computational fluid dynamics (CFD) and multiblock model is used for modelling crystal growth in a 100 dm3 suspension crystallizer equipped with two turbine impellers. Local hydrodynamics and crystal suspension densities were modelled using CFD. Simulation results were compared with experimental results to verify flow profile and slip velocities (Hatakka et al., 2008, 2009), and classification of crystals. Results from CFD simulations were then translated to a proper form and used as input data for the multiblock model.The same multiblock model has previously been used successfully for modelling gas–liquid systems (Laakkonen, 2006). For this study a growth model for potassium dihydrogen phosphate (KDP) was imported into the multiblock model. We used the power-law growth model including activity-based driving force. The growth model was developed based on single crystal experiments of KDP (Liiri et al., 2006). Growth of KDP crystals in the 100 dm3 suspension crystallizer was simulated with the multiblock model. Verification was done by comparing the simulated results with results from crystal growth experiments.