We present a comprehensive literature review on the two-phase bubble column; in this review we deeply analyze the flow regimes, the flow regime transitions, the local and global fluid dynamics parameters, and the mass transfer phenomena. First, we discuss the flow regimes, the flow regime transitions, the local and global fluid dynamics parameters, and the mass transfer. We also discuss how the operating parameters (i.e., pressure, temperature, and gas and liquid flow rates), the operating modes (i.e., the co-current, the counter-current and the batch modes), the liquid and gas phase properties, and the design parameters (i.e., gas sparger design, column diameter and aspect ratio) influence the flow regime transitions and the fluid dynamics parameters. Secondly, we present the experimental techniques for studying the global and local fluid dynamic properties. Finally, we present the modeling approaches to study the global and local bubble column fluid dynamics, and we outline the major issues to be solved in future studies.

Two-Phase Bubble Columns: A Comprehensive Review

Two-phase bubbly flow simulation using CFD method: A review of models for interfacial forces

CFD simulations of a bubble column with and without internals by using OpenFOAM

Multiscale multiphase phenomena in bubble column reactors: A review

Abstract The effect of two structurally diverse protein emulsifiers, β-lactoglobulin and β-casein, upon the break-up behaviour of a single aqueous droplet in a Couette flow field has been studied over a wide range of protein concentrations for bulk viscosity ratios between 8 × 10−5 and 0.05. It has been found that β-casein and low concentrations (⩽10−2 g l−1) of β-lactoglobulin cause the droplets to be at least as stable as expected from conventional theories on the basis of their equilibrium interfacial tension. In such cases the presence of the emulsifier at the deforming interface is thought to enhance the interfacial elasticity. This effect can be characterized by an effective interfacial tension, which is higher than the equilibrium value. High concentrations of β-lactoglobulin (⩾ 10−1 g l−1), on the other hand, have been shown to cause droplets to be less stable than would have been predicted from the equilibrium interfacial tension. It is thought that an interfacial protein network is formed, which limits the droplet deformation and makes the droplet interface rigid with respect to tangential stresses. As a result, the critical deformation and capillary number are found to be essentially independent of the viscosity ratio. It is proposed that the interfacial structure may be probed using a combination of interfacial shear and dilational rheological measurements. From this type of analysis it may be possible to predict the break-up stability of droplets.

Behaviour of droplets in simple shear flow in the presence of a protein emulsifier Colloids and Surfaces A: Phsysicochemical and Engineering.

Bubble properties, such as local gas holdup, bubble frequency, bubble velocity, bubble size, and interfacial area concentration, are of great significance for the design and scale-up of bubble columns. In the present study, bubble properties in a 0.15 m in diameter bubble column were measured by a dual-tip conductivity probe. A new method was proposed to establish the relationship between chord length distribution (CLD) and bubble size distribution (BSD) without the assumption of fixed bubble aspect ratio. The bubble velocity and BSD measured by the probe were validated by a high speed camera in a square column. The results indicate that considering the decreasing of bubble aspect ratio with bubble diameter is required to obtain accurate BSD from measured CLD. Furthermore, the measured bubble properties at different axial positions show that the flow development is much more rapid in the churn-turbulent regime than that in the homogeneous regime. It is also found that the bubble breakage is dominant over the bubble coalescence in the homogeneous regime due to the large bubbles generated at the perforated distributor. The measured results provide a benchmark data for validation of CFD simulation.

Bubble properties measurement in bubble columns: From homogeneous to heterogeneous regime

CFD simulation of gas-liquid flow in stirred tanks: Effect of drag models

Hydrodynamics in a 0.8 m diameter bubble column with pin-fin tube internals covering 9.2% total cross-sectional area of the column is experimentally investigated. The experimental results indicated that pin-fin tube internals significantly affect gas holdup and liquid velocity. It can be inferred from the measured data that the pin fins on the tubes obviously reduce the distributor region in the column. Furthermore, non-uniform arrangement of pin-fin tube internals through symmetrically removing two tubes near column wall gives rise to severe gas short-circuiting and even no downward liquid flow there, while there is imperceptible influence for bubble column with non-uniform plain tube internals.

Hydrodynamics in bubble columns with pin-fin tube internals

Modeling the effects of solid particles in CFD-PBM simulation of slurry bubble columns

In the present study, influence of interfacial forces, including drag force and lateral forces (lift force, turbulent dispersion force and wall force) on the hydrodynamics in pilot-scale bubble columns with internals is analyzed. The results indicate that the lateral forces may be optional for the hollow columns, but they are required to accurately predict flow characteristics in the bubble columns with internals. Furthermore, it has been found that the bubbly flow behavior in the bubble columns with internals is more sensitive to the lateral forces in comparison with those without internals, and the complex geometry significantly alters the response of bubbly flow to the interfacial forces. In addition, despite the insignificant effect on gas holdup, the presence of internals gives rise to an enhancement of large-scale liquid circulation due to the remarkable decrease of turbulent viscosity.

Xiaoping Guan

Papers

Bubble properties measurement in bubble columns: From homogeneous to heterogeneous regime

CFD simulation of gas-liquid flow in stirred tanks: Effect of drag models

Hydrodynamics in bubble columns with pin-fin tube internals

Modeling the effects of solid particles in CFD-PBM simulation of slurry bubble columns

CFD simulation of pilot-scale bubble columns with internals: Influence of interfacial forces