Modeling of Microbubble Flow and Coalescence Behavior in the Contact Zone of a Dissolved Air Flotation Tank Using a Computational Fluid Dynamics–Population Balance Model

Chen, Aqiang; Yang, Wensan; Geng, Shujun; Gao, Fei; He, Taobo; Wang, Zhenbo; Huang, Qingshan

doi:10.1021/acs.iecr.9b03604

Cited by 10 publications

(2 citation statements)

References 52 publications

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“…Despite its simple construction, it is hard to anticipate the behavior inside a BCR because of the highly chaotic nature of bubble swarms. Therefore, studies on bubble dynamics inside BCRs have attracted many research groups and became a major area of interest in the field of multiphase flow reactors [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Bubble Column CFD Model with Effects of Forced Oscillations on Bubble Dynamics

2021

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Bubble size distribution has a significant effect on gas holdup, residence time distribution, and mass transfer in bubble column reactors (BCRs). The occurrence of small gas bubbles has potential advantages such as a limited residence time distribution and perfect gas‐liquid phase contact. Gas‐liquid mass transfer in bubble columns can be significantly enhanced by subjecting the liquid phase to low‐frequency vibrations. However, the effect of vibration frequency on bubble formation and hydrodynamic characteristics in BCRs is still not well understood. Herein, a 3D numerical model of a BCR was developed to study the effect of vibration frequency on bubble dynamics under different operating conditions. The Sauter mean bubble diameter was found to be approximately inversely proportional to the vibration frequency.

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Section: Introductionmentioning

confidence: 99%

Bubble Column CFD Model with Effects of Forced Oscillations on Bubble Dynamics

2021

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“…This depends on the advantages of the E–E approach that can simulate the flow of bubbles with variable sizes. The population balance model (PBM) has been introduced to consider the breakup and coalescence of bubbles of set size 72,73 . However, it should be noted that in available researches, due to the lack of in‐depth understanding of the mechanism related to gas–liquid–solid multiphase interactions, many calculation models are established based on many assumptions and empirical parameters, which are less universal.…”

Section: Theories Of Computational Fluid Dynamics Numerical Simulation In Studying Flotationmentioning

confidence: 99%

Recent advances in computational fluid dynamics simulation of flotation: a review

Wang

Yan

et al. 2021

Asia-Pacific J Chem Eng

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Flotation process is a multi‐phase and multi‐scale complex flow system, in which hydrodynamics plays an indispensable role. In recent years, computational fluid dynamics (CFD) numerical simulation has gradually become a powerful tool for studying flotation. In this review, the theories of CFD numerical simulation in flotation research were reviewed, involving various turbulence models and multi‐phase flow simulation approaches. An attempt has been made to analyze and discuss the characteristics and applicability of different turbulence models and multi‐phase flow simulation approaches in flotation researches in detail. The CFD simulation of two commonly used flotation devices, that is, mechanically agitated flotation machine and flotation column, has been reviewed in detail. The detailed principles, operation, and hydrodynamic of flotation devices were discussed from the viewpoint of CFD. The advances made in CFD simulation for studying flotation process, including particle suspension, bubble dispersion, particle–bubble collision, attachment, and detachment subprocesses have been critically analyzed. Focused analysis was given on the influence mechanism of turbulence on the particle–bubble interactions. Finally, the gaps in the available literature are discussed and potential research directions are also proposed.

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Numerical investigation on mixing behaviour in the contact zone of an industrial‐scale dissolved air flotation tank

Chen,

Huang,

Hao

2024

Can J Chem Eng

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The mixing behaviour of the wastewater and the recycle bubbly water in the contact zone could affect the separation performance of dissolved air flotation systems. In this study, the mixing characteristics in the contact zone of an industrial‐scale dissolved air flotation tank were investigated using the computational fluid dynamics method. At first, the influence of the turbulence model on the simulation results was clarified. It is demonstrated that the realizable k‐ε model could predict the gas holdup distribution with better accuracy, and the maximum relative deviation between the predicted gas holdup and the experimental results is only 10%. The influence of the geometry and operating parameters on the mixing process was then studied numerically. It is found that the mixing performance in the contact zone could be improved by decreasing the height position of the nozzle inlet in a certain range. The reason is that microbubbles disperse better in the bottom region and a double circulation flow state forms in the contact zone when the nozzle inlet is installed at a low height. Additionally, the mixing process could be further enhanced by decreasing the diameter of the nozzle inlet. As to the operating conditions, increasing the recycle ratio could not only increase the gas holdup but also improve the mixing performance in the contact zone. When the recycle flow rate remains constant, increasing the wastewater flow rate will lead to a decrease in gas holdup and deterioration of the mixing effect.

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Modeling of Microbubble Flow and Coalescence Behavior in the Contact Zone of a Dissolved Air Flotation Tank Using a Computational Fluid Dynamics–Population Balance Model

Cited by 10 publications

References 52 publications

Bubble Column CFD Model with Effects of Forced Oscillations on Bubble Dynamics

Bubble Column CFD Model with Effects of Forced Oscillations on Bubble Dynamics

Recent advances in computational fluid dynamics simulation of flotation: a review

Numerical investigation on mixing behaviour in the contact zone of an industrial‐scale dissolved air flotation tank

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