Computational-fluid-dynamics (CFD) modelling of an industrial crystallizer: application to the forced-circulation reactor.

The CFD (computational fluid dynamics) technique is used to describe the mixing conditions in a pilot-scale FCC (forced-circulation crystallizer) and to study the impact of flow rate and aspect ratio on local flow conditions and RTD (residence-time distribution) in the crystallizer. The analysis adequately predicts the oscillating flow and two-phase (gas-liquid) interaction at the free surface. A comparison has been made between the CFD predictions and models of RTD. The results support the use of CFD methodology as an aid to optimization of commercial-scale FCC design.