AbstractThe influence of hydrodynamic conditions in dual‐impeller crystallizers at different impeller spacings on nucleation kinetics was investigated. Dual‐pitched‐blade turbine (2 PBT) and dual‐straight‐blade turbine (2 SBT) impeller configurations were used. To analyze hydrodynamic conditions at different impeller spacings, a computational fluid dynamics model was developed and validated by experimentally determining mixing time and power input. Results show that nucleation kinetics in the 2 SBT impeller system is affected by the characteristic microscale parameters. The same was not observed in the 2 PBT impeller system. Also, as a consequence of higher shear stress values, smaller but less agglomerated crystals were obtained in 2 SBT impeller systems.