Improving bubble column modelling by using hybrid multiphase simulation with refined mesh and reformed sparger

Abstract

Gas-liquid contactors like bubble columns are crucial in chemical industries, yet conventional meshing methods often overlook local fluctuations, hampering accurate simulation of viscosity's damping effect on bubble behaviour. This leads to reduced gas hold-up and constrained mass transfer rates. To address these issues, a novel Computational Fluid Dynamics approach named Hybrid Multi-Phase Modelling with a Refined Mesh and Reformed Sparger is proposed. This method integrates a Refined Exterior Prismatic Hexahedral Core Mesh, combining unstructured hexahedral and prism meshes to accurately model fluid flow and bubble interactions. Global adaptive mesh refinement enhances simulation accuracy by refining mesh interfaces based on local error estimation. Additionally, a Pento-Centric Conical Orifice Sparger is introduced to produce smaller continuous bubbles and uniformly distribute them, increasing gas holdup and reducing turbulence. Finally, a Hybrid Volume of Flow with Discrete Element Method (VOF-DEM) is employed to address complex geometries, distinguishing phase interfaces with VOF and considering viscosity effects with DEM. Comparative analysis with existing techniques reveals significant improvements: skewness reduced to 0.07, orthogonal velocity increased to 0.98, and liquid velocity reached 0.25 m/s. Overall, this approach enhances gas-liquid contactor simulations, offering improved accuracy and performance in predicting bubble behaviour and mass transfer rates.