The flows in stage-wise liquid-liquid extraction devices include both phase segregated and dispersed flow regimes. As a additional layer of complexity, for extraction equipment such as the annular centrifugal contactor, free-surface flows also play a critical role in both the mixing and separation regions of the device and cannot be neglected. Traditionally, computional fluid dynamics (CFD) of multiphase systems is regime dependent—different methods are used for segregated and dispersed flows. A hybrid multiphase method based on the combination of an Eulerian multifluid solution framework (per-phase momentum equations) and sharp interface capturing using Volume of Fluid (VOF) on selected phase pairs has been developed using the open-source CFD toolkit OpenFOAM. Demonstration of the solver capability is presented through various examples relevant to liquid-liquid extraction device flows including three-phase, liquid-liquid-air simulations in which a sharp interface is maintained between each liquid and air, but dispersed phase modeling is used for the liquid-liquid interactions.

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Hybrid Multiphase CFD Solver for Coupled Dispersed/Segregated Flows in Liquid-Liquid Extraction

Abstract The coalescence phenomenon of drops in liquid/liquid systems is reviewed with particular focus on its technical relevance and application. Due to the complexity of coalescence, a comprehensive survey of the coalescence process and the numerous influencing factors is given. Subsequently, available experimental techniques with different levels of detail are summarized and compared. These techniques can be divided in simple settling tests for qualitative coalescence behavior investigations and gravity settler design, single-drop coalescence studies at flat interfaces as well as between droplets, and detailed film drainage analysis. To model the coalescence rate in liquid/liquid systems on a technical scale, the generic population balance framework is introduced. Additionally, different coalescence modeling approaches are reviewed with ascending level of detail from empirical correlations to comprehensive film drainage models and detailed computational fluid and particle dynamics.

/pdf/drop-coalescence-in-technical-liquid-liquid-applications-a-1g9yygoy0z.pdf

Drop coalescence in technical liquid/liquid applications: a review on experimental techniques and modeling approaches

Rational selection of MIEC materials in energy production processes

https://biblio.ugent.be/publication/4225117/file/4225123.pdf

Model-based analysis of high shear wet granulation from batch to continuous processes in pharmaceutical production - A critical review

With limits on population and economic growth (i.e. within a steady-state economy), free food, and free energy as well, would be a blessing. But in the current growth context they would be a curse; free energy would simply make it easier for a growth society to destroy the ecosystem. This consideration itself is a powerful argument against growthmania – any context that converts free energy and free food from a boon to a bane must embody some serious irrationalities.

steady state〔邦文〕

In this work, a one-group reduced population balance model based on the one primary and one secondary particle method (OPOSPM) developed recently by Attarakih et al. (In Proceedings of the 19th European Symposium on Computer Aided Process Engineering, ESCAPE-19, Cracow, Poland, June 14−17, 2009; Jezowski, J., Thullie, J., Eds.; Elsevier: New York, 2009; ISBN-13: 978-0-444-53433-0) is implemented in the commercial computational fluid dynamics (CFD) package FLUENT 6.3 for solving the population balance equation in a combined CFD−population balance model (PBM). The one-group reduced population balance conserves the total number (N) and volume (α) concentrations of the population by directly solving two transport equations for N and α and provides a one-quadrature point for closing the unclosed integrals in the population balance equation. Unlike the published two-equation models, the present method offers accuracy improvement and internal consistency (with respect to the continuous population balance equatio...

One-Group Reduced Population Balance Model for CFD Simulation of a Pilot-Plant Extraction Column

CFD-population balance modeling and simulation of coupled hydrodynamics and mass transfer in liquid extraction columns

Simulation and experimental validation of reactive bubble column reactors

Fluid dynamics of the single-phase and two-phase flow in a segment of a rotating disc contactor (RDC) liquid–liquid extraction column with 450 mm inner diameter were studied by performing computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) measurements. The fluid dynamics were investigated to test the predictivity of CFD at industrial scale. Different turbulence models in conjunction with the Eulerian approach were applied in the single-phase and two-phase simulations. The turbulent flow characteristics were analyzed by PIV measurements to validate the CFD simulations. An iso-optical system composed of CaCl2/water–butylacetate allows for the two-phase PIV measurements. Local turbulent energy dissipation was derived from velocity gradients in PIV data. In this connection, the influence of the PIV spatial resolution on the measured energy dissipation was also analyzed, and different fit functions were tested to scale the measured energy dissipation. Simulated velocity fields as well as the energy dissipation were compared with the experimental PIV data. The results from the simulations and experiments are in good agreement. The work shows that CFD can predict hydrodynamic characteristics even at bigger scales but is still subject to some minor restrictions. © 2010 American Institute of Chemical Engineers AIChE J, 2011

CFD simulations and particle image velocimetry measurements in an industrial scale rotating disc contactor

https://onlinelibrary.wiley.com/doi/pdf/10.1002/cite.201900109

Mark W. Hlawitschka

Papers

One-Group Reduced Population Balance Model for CFD Simulation of a Pilot-Plant Extraction Column

CFD-population balance modeling and simulation of coupled hydrodynamics and mass transfer in liquid extraction columns

Simulation and experimental validation of reactive bubble column reactors

CFD simulations and particle image velocimetry measurements in an industrial scale rotating disc contactor

Models for the Numerical Simulation of Bubble Columns: A Review