Stability Issues for Gas-Liquid Flows in Bubble Columns

Law, Deify; Battaglia, Francine; Heindel, Theodore J.

doi:10.1115/imece2007-43517

Cited by 3 publications

(4 citation statements)

References 11 publications

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“…The BP+BIT model predicts a slightly larger gas holdup as compared to the multiphase k-c model but neither 2D case compares well with the experiments. The simulation predicts the experiment well at 1 crnls superficial gas velocity that employs the BP+BIT model, which is expected for a homogeneous flow [30,34].…”

Section: Results and Discussion Bubble Column (Bc) Studymentioning

confidence: 99%

Simulating Gas-Liquid Flows in an External Loop Airlift Reactor

Law

Battaglia

Heindel

2008

Volume 10: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B, and C

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The external loop airlift reactor (ELALR) is a modified bubble column reactor that is composed of two vertical columns that are connected with two horizontal connectors. Airlift reactors are utilized in fermentation processes and are preferred over traditional bubble column reactors because they can operate over a wider range of conditions. Computational fluid dynamics (CFD) simulations can be used to enhance our understanding of the hydrodynamics within these reactors. In the present work, the gas-liquid flow dynamics in an external loop airlift reactor are simulated using CFDLib with an Eulerian-Eulerian ensembleaveraging method in two-dimensional (2D) and three-dimensional (3D) coordinate systems. In addition, models are employed for the interphase momentum transfer drag coefficient and turbulence behavior. The CFD simulations for temporal and spatial averaged gas holdup are compared to the experimental measurements of Jones and Heindel [1] who used a 10.2 cm diameter ELALR over a range of superficial gas velocities from 0.5 to 20 cm/s. The effect of specifying a mean bubble diameter size for the CFD modeling is examined. The objectives are to validate 2D and 3D CFD simulations with experimental data in order to predict the hydrodynamics in an airlift reactor for future studies on scale-up and design. ABSTRACTThe external loop airlift reactor (ELALR) is a modified bubble column reactor that is composed of two vertical columns that are connected with two horizontal connectors. Airlift reactors are utilized in fermentation processes and are preferred over traditional bubble column reactors because they can operate over a wider range of conditions. Computational fluid dynamics (CFD) simulations can be used to enhance our understanding of the hydrodynamics within these reactors. In the present work, the gas-liquid flow dynamics in an external loop airlift reactor are simulated using CFDLib with an Eulerian-Eulerian ensemble-averaging method in twodimensional (2D) and three-dimensional (3D) coordinate systems. In addition, models are employed for the interphase momentum transfer drag coefficient and turbulence behavior. The CFD simulations for temporal and spatial averaged gas holdup are compared to the experimental measurements of Jones and Heindel [I] who used a 10.2 em diameter ELALR over a range of superficial gas velocities from 0.5 to 20 cm/s. The effect of specifying a mean bubble diameter size for the CFD modeling is examined. The objectives are to validate 2D and 3D CFD simulations with experimental data in order to predict the hydrodynamics in an airlift reactor for future studies on scale-up and design.

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Section: Results and Discussion Bubble Column (Bc) Studymentioning

confidence: 99%

Simulating Gas-Liquid Flows in an External Loop Airlift Reactor

Law

Battaglia

Heindel

2008

Volume 10: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B, and C

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“…Therefore, CFD simulation substituted full-scale experimentations in the bubble column, which are expensive. Hence, validating CFD models is essential for studying bubble columns and gas–liquid systems to consider a more cost-effective approach …”

Section: Introductionmentioning

confidence: 99%

“…Hence, validating CFD models is essential for studying bubble columns and gas−liquid systems to consider a more cost-effective approach. 25 Two approaches of Eulerian−Lagrangian, 26−28 and Eulerian− Eulerian 29−33 approaches have been employed for the CFD simulations of bubble columns or gas−liquid flow systems. In the Eulerian−Lagrangian model, the continuous phase is described by a Eulerian representation.…”

Section: Introductionmentioning

confidence: 99%

3D CFD Simulation of a Bubble Column with Internals: Validation of Interfacial Forces and Internal Effects for Local Gas Holdup Predictions

Al-Naseri,

Schlegel,

Al-Dahhan

2023

Ind. Eng. Chem. Res.

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“…For example, bubble columns reactors are used in a wide spectrum of chemical and energy applications (van Sint Annaland et al, 2005, Darmana et al, 2007, Law et al, 2008, Chen et al, 2009, with typical examples including Fischer-Tropsch synthesis (Guillen et al, 2011), methanol and dimethylether syntheses (Wu & Gidaspow, 2000), coal liquefaction (Law et al, 2007, Law et al, 2011, or algae bioreaction (Singh & Sharma, 2012) etc. Also, nucleate pool boiling is applied in different industrial processes such as distillation or thermal transport (Arndt, 1981, Blake & Gibson, 1987.…”

Section: Introductionmentioning

confidence: 99%

Spherical bubble dynamics in a bubbly medium using an Euler–Lagrange model

Chahine

Hsiao

2015

Chemical Engineering Science

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For applications involving large bubble volume changes such as in cavitating flows and in bubbly two-phase flows involving shock and pressure wave propagation, the dynamics, relative motion, deformation, and interaction of bubbles with the surrounding medium play crucial roles and require accurate modeling. We present in this paper a fundamental study of the dynamic oscillations of a 'primary' bubble in a bubbly mixture using a two-way coupled Euler-Lagrange model. It addresses a simplified spherical configuration while using the full three-dimensional code. A main objective of the study is to investigate how the dynamics of a 'primary' bubble is affected by the presence of a surrounding bubbly medium and how it differs from its behavior in a pure liquid. This The simulations clearly indicate that the surrounding microbubbles absorb energy emitted from the primary bubble during its oscillations. This results in a reduction of the maximum radius and the period of oscillations of the primary bubble as compared to the dynamics in the pure liquid. Also, accounting for the dynamics of the field bubbles brings out the presence in the two-phase medium of a phase shift between density and pressure distributions. Such a shift is not captured by two-phase homogeneous medium models. These effects increase with increase in the mixture void fraction and in the initial bubble sizes in the mixture. The numerical observations are found to be in good qualitative agreements with previously published experimental data (Jayaprakash et al., 2011) investigating spark generated bubble dynamics in a bubbly medium.

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Stability Issues for Gas-Liquid Flows in Bubble Columns

Cited by 3 publications

References 11 publications

Simulating Gas-Liquid Flows in an External Loop Airlift Reactor

Simulating Gas-Liquid Flows in an External Loop Airlift Reactor

3D CFD Simulation of a Bubble Column with Internals: Validation of Interfacial Forces and Internal Effects for Local Gas Holdup Predictions

Spherical bubble dynamics in a bubbly medium using an Euler–Lagrange model

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