Compartment Model for Liquid-Liquid Extraction Columns

ABSTRACT

The simulation of stirred liquid–liquid extraction columns with CFD still requires significant computing resources. Therefore, a CFD-based compartment model was developed for a simulation of a representative amount of drops while keeping the computing effort low. The model is based on the velocity profile of the continuous phase generated by a single-phase CFD simulation. The drop movement, mass transfer, accumulation of the dispersed phase under stators, coalescence, and breakage are modeled according to this flow profile. The simulation of the fluid dynamics is in good agreement with published experiments of a DN80 Kuehni extraction column.

KEYWORDS:

• Compartment model
• multiphase
• lagrange tracking
• time-driven constant-number monte-carlo
• CFD

Symbols

Table

Sub- and superscripts

$\mathrm{\infty }$	=	stationary
$\mathrm{a}\mathrm{x}$	=	axial
$\mathrm{d}$	=	dispersed phase
$\mathrm{c}$	=	continuous phase

Abbreviations

CFD	=	Computational Fluid Dynamics
PBE	=	Population Balance Equation
EFCE	=	European Federation Chemical Engineering