Operating Regimes and Hydrodynamics of a Rotating‐Disc Contactor

Abstract

The operating regimes for a pilot‐scale rotating‐disc contactor (RDC) were investigated by a computational fluid dynamics/population balance model (CFD‐PBM) simulation. The model successfully predicted the critical rotor speed, which divided the entire operating range into two regions. In the low rotor speed region, the input energy was insufficient to break droplets, resulting in an almost constant droplet diameter. Therefore, the increasing revolution slightly affected the interfacial area, while the axial mixing became severe. In contrast, the interfacial area increased significantly in the high rotor speed region because of the increased breakage rate. Moreover, the axial mixing extent increased slightly because the dispersed‐phase accumulation enhanced the advection effect. The results indicate that the CFD‐PBM approach can be applied to engineering practice for extractors.

Numerical Investigation of Mass Transfer Prediction in Various Sizes of Kenics Static Mixers on Extraction: Corrected with Eddy Cell Model and Droplet Size Effect Model

“…In the liquid–liquid system, the CFD-PBM method, widely used in the CFD simulation of static mixers, was adopted to describe the distribution variation of multisize droplets under turbulent flowing conditions. − The population balance model is atop the transport equation of the number density function at a certain time, t , expressed as n ( d k , t ), where d k is the diameter of the droplet. Given that the liquid is considered incompressible during the extraction process and the catechol mass transfer amount is small, the growth of droplets can be negligible . Therefore, the ∇ [ Gn ( d k ,t )] term in the original population balance equation, which represents droplet growth, is assumed to be zero.…”

“…Given that the liquid is considered incompressible during the extraction process and the catechol mass transfer amount is small, the growth of droplets can be negligible. 43 Therefore, the ∇[Gn(d k ,t)] term in the original population balance equation, which represents droplet growth, is assumed to be zero. The transport equation for the number density function is given as eq 35…”

Design of Extractive Reaction Systems

“…Accordingly, phenomenological models can be inserted as submodels (kernels) into the CFD model, thus, allowing a space‐dependent evolution of the drop size distribution. Examples for the integration of PBM in a CFD environment have recently been published , . However, these examples do not consider reactions due to high computational demands.…”

CFD-PBM Simulation of Sauter Mean Diameter in a Stirred Sieve-Plate Extraction Column

“…In this regard, the CFD-population balance model (PBM)coupled simulation method was used by many researchers to model the evolution of DSD and calculate d 32 . After a comprehensive validation for a pilot-scale rotating disc contactor by CFD-PBM simulation, 25 Chen et al 26 investigated the operating regimes and predicted the critical rotor speed accurately based on the simulated d 32 . Sen et al 27 performed CFD-PBM simulations of a pulsed sieve-plate column with a 2D computational model, and spatial and temporal variations of d 32 and holdup were captured.…”