Hydrodynamics of air–kerosene bubble column under elevated pressure in homogeneous flow regime

Abstract

A multiphase computational fluid dynamics (CFD) model coupled with the population balance equation (PBE) was developed in a homogeneous air–kerosene bubble column under elevated pressure ( P ). The specific pressure drop (Δ P / L ), gas holdup ( α G ), and Sauter mean diameter ( d 32 ) were experimentally measured in the bubble column with 1.8 m height and 0.1 m inner diameter, which was operated at a superficial gas velocity of 12.3 mm·s −1 , and P = 1–35 bar (1 bar = 10 5 Pa). A modified drag coefficient model was proposed to consider the effect of bubble swarm and pressure on hydrodynamics of the bubble column. The Luo breakage model was modified to account for liquid density, viscosity, surface tension and gas density. The Δ P / L , α G , and d 32 obtained from the CFD model were compared with experimental data, and the gas density-dependent parameters of the CFD model were identified. With increasing P from 1 to 35 bar, the α G varied from 5.4% to 7.2% and the d 32 decreased from 2.3 to 1.5 mm. The CFD-PBE model is applicable to predict hydrodynamics of pressurized bubble columns for gas–organic liquid in the homogeneous regime.