(216c) Calculation of Column Height Using Computational Fluid Dynamics

Application of the Dispersion Model on the HTU-NTU concept makes it possible to consider the non ideal flow regime in an Rotating Disk Contactor (RDC) beyond idealized plug flow regime. As axial dispersion effects for continuous and disperse phase can take strong influence on the extraction efficiency of an extractor, knowledge of these layout parameters is essential. In his work it could be shown that a prediction of the axial dispersion coefficient using CFD is possible. Therefore a 150mm RDC column was set up and measurements of residence time distribution using the transient tracer method were realized. For the simulation of the complex flow pattern in the RDC numerous simulations, implementing investigation of mesh resolution (up to 10mio cells) and turbulence models (favourably realizable k-epsilon and RSM) were compared. The tracer experiments for single phase flow could be verified using the Discrete Phase Model (DPM). Therefore, mass less particles were tracked through the flow field. For the investigations of the two phase flow, the Euler-Euler Model has been successfully applied. Subsequent comparison of simulation results with experimentally obtained data from LDA, PIV and pressure based hold-up measurements showed a good correlation.