(366d) Mass Transfer Enhancement of Non-Dispersive Solvent Extraction By Dean Vortices: Modeling, Experiments and Optimization
Dean vortices induced in helical hollow fiber membranes (HHFM) are simplest and most effective to increase the mass transfer rate of the membrane processes. As such, it is important to understand the underlying mechanisms of the mass transfer behavior of HHFM processes by modeling and simulation. This work focuses on the mass transfer enhancement of non-dispersive solvent extraction with Dean vortices in purified terephthalic acid (PTA) wastewater treatment by modeling, experiment and optimization. Experiments showed that the mass transfer rate of the HHFM extraction was doubly enhanced compared with the straight hollow fiber membrane extraction. A new mathematical model of the HHFM extraction was developed in an orthogonal helical coordinate system with a perturbation solution to describe the velocity profile. The key parameters affecting the intensity of Dean vortices of HHFM extraction are the Graetz number of the lumen side and the dimensionless curvature. Numerical analysis of the mass transfer showed that the highest concentration area exists in the area of the radial velocity vortices, where the velocity of Dean vortices is zero. An optimal group of operating parameter for PTA wastewater treatment is suggested.