CFD Simulation on Influence of Superficial Gas Velocity, Column Size, Sparger Arrangement, and Taper Angle on Hydrodynamics of the Column Flotation Cell

Chakraborty, Debadi; Guha, Mriganshu; Banerjee, P. K.

doi:10.1080/00986440902897376

Cited by 17 publications

(11 citation statements)

References 28 publications

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“…Gas-lift bioreactors are provided with various devices which promote the circulation of the broths as internal or external-loop (split-cylinder or draft tube internal-loop, with or without impeller driven loop, packed bed, external loop, etc.) (Chakraborty et al, 2009;Moraveji et al, 2013). Because this flow pattern exposes the cells to fluctuating growth conditions, the uniform distributions of the nutrients, dissolved oxygen concentration, temperature, or shear stress magnitude represent the main factors controlling the gas-lift bioreactors performance.…”

Section: Introductionmentioning

confidence: 99%

Distribution of Mixing Efficiency in a Split-Cylinder Gas-Lift Bioreactor with ImmobilizedYarrowia LipolyticaCells Used for Olive Oil Mill Wastewater Treatment

Matran

Galaction

Blaga

et al. 2015

Chemical Engineering Communications

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The distribution of mixing in a split-cylinder gas-lift bioreactor has been investigated for suspensions of immobilized Y. lipolytica cells with particles diameter varying between 3 and 4.2 mm. The results indicated important variation of mixing time on the height of riser or downcomer, as well as different behavior of suspensions flows in these two regions. Therefore, for the riser, the mixing efficiency increases from its bottom to the top, the biocatalyst particles with intermediary size (3.6 mm diameter) allowing reaching the most intense circulation of suspension. The analysis of the suspension flow in the downcomer region revealed that the intermediary positions are associated with the highest mixing mainly for the largest immobilized yeast particles (4.2 mm diameter). In both cases, the influence of aeration on turbulence extent is positive only for air superficial velocity up to 1.05 -1.35x10 -3 m/s, the magnitude of this effect being correlated with the biocatalyst size and position on the riser or downcomer. By means of the experimental data, mathematical correlations for mixing time have been proposed for each circulation region, taking into consideration both the operational parameters and the Downloaded by [University of Otago] at 10:37 05 October 2015 2 distance from the bioreactor bottom. These equations offer a good concordance with the experiment, the average deviation being of 5.82 for the riser and 6.06% for the downcomer zone.

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Section: Introductionmentioning

confidence: 99%

Distribution of Mixing Efficiency in a Split-Cylinder Gas-Lift Bioreactor with ImmobilizedYarrowia LipolyticaCells Used for Olive Oil Mill Wastewater Treatment

Matran

Galaction

Blaga

et al. 2015

Chemical Engineering Communications

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confidence: 99%

“…Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD) 2009; Chakraborty, Guha, and Banerjee, 2009). For column flotation cells, CFD modelling has been applied to predict the average gas holdup for the whole column (Koh and Schwarz, 2009;Chakraborty, Guha, and Banerjee, 2009). However, the gas holdup has been observed to vary with height along the collection zone of the flotation column (Gomez et al, 1991(Gomez et al, , 1995Yianatos et al, 1995), increasing by almost 100% from the bottom to the top of the column.…”

mentioning

confidence: 99%

Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD)

Mwandawande

Akdogan

Bradshaw

et al. 2019

J. S. Afr. Inst. Min. Metall.

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“…Several numerical studies were conducted on various industrial applications of two-phase flow by using the famous Euler-Euler two-fluid model because of the complexity and immense cost involved in the experimental work. Chakraborty et al [6] used the Euler-Euler model to examine the influence of gas flow velocity, reactor geometry, and sparger arrangement on the hydrodynamic properties of the reactor. The results suggested the use of low gas flow rates and uniformly distributed gas spargers to improve the performance of the two-phase reactor [6].…”

mentioning

confidence: 99%

“…Chakraborty et al [6] used the Euler-Euler model to examine the influence of gas flow velocity, reactor geometry, and sparger arrangement on the hydrodynamic properties of the reactor. The results suggested the use of low gas flow rates and uniformly distributed gas spargers to improve the performance of the two-phase reactor [6]. Therefore, the design of the gas sparger or injecting nozzle is of considerable importance for increasing mass transfer coefficient and gas hold-up to enhance carbonation.…”

mentioning

confidence: 99%

Numerical Study on the Effects of Contraction Ratio in a Two-Phase Flow Injection Nozzle

Ali¹,

Kim²,

Kim³

et al. 2016

OJFD

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The Euler-Euler numerical method was used to investigate the effects of contraction ratio on twophase flow mixing with mass transfer in the flow injection nozzle. The geometric shape of the nozzle was modified to improve carbonation efficiency. A gas inlet hole was created to increase the flow mixing of CO 2 with water. A nozzle throat was also introduced to increase the gas dissolution by increasing flow rates. Various contraction ratios of nozzle throat, inlet gas and liquid velocities, and gas bubble sizes were employed to determine their effects on gas holdup , gas concentration, and mass transfer coefficient. Results revealed that the flow injection nozzle with high contraction ratios improved carbonation because of high gas holdup. Gas concentration was directly related to contraction ratio and gas flow velocities. Carbonation reduced when high liquid velocities and large gas bubbles were employed because of inefficient flow mixing. This study indicated that flow injection nozzle with large contraction ratios were suitable for carbonation because of their ability to increase gas holdup , gas concentration, and mass transfer coefficient.

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CFD Simulation on Influence of Superficial Gas Velocity, Column Size, Sparger Arrangement, and Taper Angle on Hydrodynamics of the Column Flotation Cell

Cited by 17 publications

References 28 publications

Distribution of Mixing Efficiency in a Split-Cylinder Gas-Lift Bioreactor with ImmobilizedYarrowia LipolyticaCells Used for Olive Oil Mill Wastewater Treatment

Distribution of Mixing Efficiency in a Split-Cylinder Gas-Lift Bioreactor with ImmobilizedYarrowia LipolyticaCells Used for Olive Oil Mill Wastewater Treatment

Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD)

Numerical Study on the Effects of Contraction Ratio in a Two-Phase Flow Injection Nozzle

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