CFD modeling of bubble columns flows: implementation of population balance

Abstract The Bubble Population Balance Equation is implemented both in the two-fluid model and in the Algebraic Slip Mixture Model. Two and three-dimensional numerical simulations of two-phase (air–water) and pseudo-two-phase (air–Therminol-Glass beads) transient flows are performed for laboratory scale bubble columns of two different diameters operated over a range of superficial gas velocities (8 to 20 cm/s) in the churn turbulent regime. The ability of the simulations to predict liquid recirculation and gas radial holdup profile, which drives the recirculation, is illustrated. The simulations also capture the effects of increased superficial gas velocity and of surface tension on bubble size distribution in agreement with observations. At all conditions a uni-modal bubble size distribution is predicted.

[1]  Sailesh Kumar,et al.  A γ-ray tomographic scanner for imaging voidage distribution in two-phase flow systems , 1995 .

[2]  Milorad P. Dudukovic,et al.  Fluid dynamic parameters in bubble columns with internals , 1999 .

[3]  Shantanu Roy,et al.  Numerical simulation of gas}liquid dynamics in cylindrical bubble column reactors , 1999 .

[4]  Sailesh Kumar,et al.  Gas‐holdup measurements in bubble columns using computed tomography , 1997 .

[5]  Milorad P. Dudukovic,et al.  Three‐dimensional simulation of bubble column flows with bubble coalescence and breakup , 2005 .

[6]  Milorad P. Dudukovic,et al.  Numerical simulation of bubble columns flows: effect of different breakup and coalescence closures , 2005 .

[7]  Rajamani Krishna,et al.  Eulerian simulations for determination of the axial dispersion of liquid and gas phases in bubble columns operating in the churn-turbulent regime , 2001 .

[8]  L. Schiller.  Uber die Grundlegenden Berechnungen bei der Schwerkraftaufbereitung , 1933 .

[9]  Carlos A. Dorao,et al.  Numerical Analysis and Experimental Validation of Bubble Size Distributions in Two-Phase Bubble Column Reactors , 2005 .

[10]  H. Svendsen,et al.  Theoretical model for drop and bubble breakup in turbulent dispersions , 1996 .

[11]  Booncheng Ong,et al.  Experimental investigation of bubble column hydrodynamics: Effect of elevated pressure and superficial gas velocity , 2003 .

[12]  P. Wilkinson,et al.  Physical aspects and scale-up of high pressure bubble columns , 1991 .

[13]  B. Launder,et al.  Mathematical Models of turbulence , 1972 .

[14]  C. Tchen,et al.  Mean Value and Correlation Problems connected with the Motion of Small Particles suspended in a turbulent fluid , 1947 .

[15]  M. Duduković,et al.  Comparison of single- and two-bubble class gas–liquid recirculation models — application to pilot-plant radioactive tracer studies during methanol synthesis , 2001 .

[16]  M. Manninen,et al.  On the mixture model for multiphase flow , 1996 .

[17]  Milorad P. Dudukovic,et al.  Numerical investigation of gas‐driven flow in 2‐D bubble columns , 2000 .

[18]  Shantanu Roy,et al.  Liquid mixing based on convection and turbulent dispersion in bubble columns , 1996 .

[19]  Liang-Shih Fan,et al.  Some aspects of high-pressure phenomena of bubbles in liquids and liquid–solid suspensions , 1999 .

[20]  Milorad P. Dudukovic,et al.  Liquid backmixing in bubble columns , 1992 .

[21]  Said Elghobashi,et al.  A two‐equation turbulence model for two‐phase flows , 1983 .

[22]  D. Drew.  Mathematical Modeling of Two-Phase Flow , 1983 .

[23]  Rajamani Krishna,et al.  Gas holdup in bubble column reactors operating in the churn‐turbulent flow regime , 1996 .

[24]  M. Duduković,et al.  Flow mapping in bubble columns using CARPT , 1990 .