Influence of the gas distributor on the local hydrodynamic behavior of an external loop airlift reactor

Lin, Jing; Han, Minghan; Wang, Tiefeng; Zhang, Tongwang; Wang, Jinfu; Ye, Jin

doi:10.1016/j.cej.2004.01.023

Cited by 44 publications

(27 citation statements)

References 32 publications

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“…The dependence of the bubble diameter on the void fraction has been shown in previous studies. The higher bubble sizes measured at the central region could be due to the coalescence phenomena [5,19]. In our case, coalescence and break-up are in equilibrium in the central zone.…”

Section: The Lateral Profiles Of the Bubble Diametermentioning

confidence: 76%

Local hydrodynamic investigation of the aeration in a submerged hollow fibre membranes cassette

Duc

Fournier

Levecq

et al. 2008

Journal of Membrane Science

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Section: The Lateral Profiles Of the Bubble Diametermentioning

confidence: 76%

Local hydrodynamic investigation of the aeration in a submerged hollow fibre membranes cassette

Duc

Fournier

Levecq

et al. 2008

Journal of Membrane Science

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“…However, high aeration rates may result in severe foaming problems and gas-stripping effects (CO 2 , ethylene or other volatile metabolites) which can inhibit plant cell growth [114,115], particularly for pneumatically agitated bioreactors. Thus, the design of an aeration system to generate as many small bubbles as possible (to increase the gas-liquid interfacial area), resulting in enhancing oxygen mass transfer, has been investigated [116]. Additionally, head-space gassing, aeration with oxygen-enriched air or increasing bioreactor pressure may be a convenient way to maintain dissolved oxygen concentration control under lower aeration rate conditions.…”

Section: Plant Cell Growth and Oxygen Demandmentioning

confidence: 99%

Bioreactor engineering for recombinant protein production in plant cell suspension cultures

Huang

McDonald

2009

Biochemical Engineering Journal

162

105

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“…Calculations of the K L /d B ratio using Equation (16), together with experimental K L a L and ε g values are measured, show that this ratio is nearly constant and is independent of U gr (Chisti, 1989;Lin et al, 2004 demonstrated that the plot of K L a L versus 6ε g /(1 -ε g ) was nearly linear in the split-rectangular reactor used in this work for the air-water system, confi rming that the K L /d B ratio, the slope of the curve, was almost constant and equal to 0.088 (R 2 = 0.994). These authors explained that the increase in K L a L was mainly due to an increase in interfacial area, while the change in K L remained weak.…”

Section: Gas-liquid Mass Transfermentioning

confidence: 99%

Study of Hydrodynamics, Mixing and Gas-Liquid Mass Transfer in a Split-Rectangular Airlift Reactor

Gourich¹,

Azher²,

Vial

et al. 2008

Can. J. Chem. Eng.

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Until recently, most investigations were focused on the effects of the downcomer-to-riser cross-section area (Snape et al., 1995), the clear liquid height and the gas-liquid separator confi guration (Siegel et al., 1986;Siegel and Merchuk, 1988;Choi and Lee, 1993), or the gas distributor type and location (Merchuk, 1986) on local and global hydrodynamic parameters. The infl uence of the physicochemical properties of the liquid phase was also taken into account, for example by Kernnard and Janekeh (1991), Li et al. (1995), Lu and Hang (1995), Molina et al. (1999) and Lin et al. (2004). Similarly, many experimental Global hydrodynamic characteristics, liquid mixing and gas-liquid mass transfer for a 63 L split-rectangular airlift reactor were studied. Correlations for gas holdup and overall liquid circulation velocity were derived for the air-water system as a function of the specifi c power input; these were compared to data and correlations for reactor volumes between 4.7 L and 4600 L. A partial recirculation of small bubbles in the riser was observed when U gr > 0.03 m/s, which was attributed to the use of a single-orifi ce nozzle as the gas phase distributor. The dimensionless mixing time and the overall axial dispersion coeffi cient were nearly constant for the range of gas fl ow rates studied. However, values of K L /d B were greater than those reported in previous studies and this is caused by the partial recirculation of the gas phase in the riser. While scale effects remain slight, the use of a gas distributor favouring this partial recirculation seems adequate for mass transfer in split-rectangular airlift reactors.On a étudié les caractéristiques hydrodynamiques globales, le mélange de liquide et le transfert de matière gaz-liquide pour un réacteur à air ascendant rectangulaire divisé. Des corrélations pour la rétention de gaz et la vitesse de circulation de liquide globale ont été calculées pour le système air-eau en fonction de la puissance spécifi que; ces corrélations ont été comparées aux données ainsi qu'à des corrélations pour des volumes de réacteur compris entre 4,7 L et 4600 L. Une recirculation partielle des petites bulles dans la colonne montante a été observée quand U gr > 0,03 m/s, qui est attribuée à l'utilisation d'un seul orifi ce pour la distribution de la phase gazeuse. Le temps de mélange adimensionnel et le coeffi cient de dispersion axiale globale sont presque constants dans la gamme de débits de gaz étudiés. Toutefois, les valeurs de K L /d B sont plus grandes que celles des études antérieures, en raison de la recirculation partielle de la phase gazeuse dans la colonne montante. Tandis que les effets d'échelle demeurent légers, l'utilisation d'un distributeur de gaz favorisant cette recirculation partielle semble adéquate pour le transfert de matière dans les réacteurs à air ascendant rectangulaire divisés.

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Influence of the gas distributor on the local hydrodynamic behavior of an external loop airlift reactor

Cited by 44 publications

References 32 publications

Local hydrodynamic investigation of the aeration in a submerged hollow fibre membranes cassette

Local hydrodynamic investigation of the aeration in a submerged hollow fibre membranes cassette

Bioreactor engineering for recombinant protein production in plant cell suspension cultures

Study of Hydrodynamics, Mixing and Gas-Liquid Mass Transfer in a Split-Rectangular Airlift Reactor

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