Experimental Study of Influence of the Impeller Spacing on Flow Behaviour of Double‐Impeller Stirred Tank

Shao, Xueming; Liu, Xiaoling; Li, Yulin

doi:10.1002/cjce.5450810613

Cited by 4 publications

(2 citation statements)

References 14 publications

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“…They found that, for long spacing between the impellers, the mixing times were nearly the longest and about 40% higher than for small spacing. This influence exists for all types of impeller configurations as the spacing affects significantly the produced flow field inside tanks [19,20]. For unaerated condition, the same dependence of mixing time on the impeller, spacing has been noticed by Magelli et al [21].…”

Section: Introductionsupporting

confidence: 59%

Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing

Issa

2016

Journal of Engineering

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Multiple or dual impellers are widely implemented in stirred contactors used in various biological processes like fermentation, water treatment, and pharmaceutical production. The spacing between impellers is considered as a crucial factor in designing of these types of contactors resulting in variation of oxygen mass transfer, mixing time, or power consumption for such biological system. A study of three parts was conducted to characterize the effect of the spacing between impellers on the most important parameters that related to biological contactor performance: oxygen mass transfer coefficientklafrom the gas phase (air) to the liquid phase (water), mixing time, and power consumption for different operating rotational speeds (1.67–3.33 rps) and for three different spacing positions. The used impellers system in the study is a dual impeller system which consists of an inverted and bladed rotated cone (IBRC) and a pitched-blade up-flow propeller (PBPU). The experimental results showed that the shorter spacing (the lower PBPU in a higher position) is more convenient, as the achieved oxygen mass transfer coefficient has showed an improvement in its values with lower mixing time and with a slight alteration in power consumption.

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Section: Introductionsupporting

confidence: 59%

Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing

Issa

2016

Journal of Engineering

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“…Moreover, the correct assignment of the strong mixing regions inside the bioreactor may be essential for the development of bioprocesses that use cells sensitive to shear forces. It is well known that impeller spacing may affect the flow pattern in the stirred tanks [24]. For the double-impeller agitator, the flow pattern strongly depends on the geometry combinations (e.g., clearance from the bottom and above the upper impeller, as well as the reactor and impeller geometry) and the mutual influence of the two impellers.…”

Section: Flow Patterns In Bioflo ® Systemsmentioning

confidence: 99%

Hydrodynamics and Mass Transfer Analysis in BioFlow® Bioreactor Systems

et al. 2020

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Biotechnological processes involving the presence of microorganisms are realized by using various types of stirred tanks or laboratory-scale dual-impeller commercial bioreactor. Hydrodynamics and mass transfer rate are crucial parameters describing the functionality and efficiency of bioreactors. Both parameters strictly depend on mixing applied during bioprocesses conducted in bioreactors. Establishing optimum hydrodynamics conditions for the realized process with microorganisms maximizes the yield of desired products. Therefore, our main objective was to analyze and define the main operational hydrodynamic parameters (including flow field, power consumption, mixing time, and mixing energy) and mass transfer process (in this case, gas–liquid transfer) of two different commercial bioreactors (BioFlo® 115 and BioFlo® 415). The obtained results are allowed using mathematical relationships to describe the analyzed processes that can be used to predict the mixing process and mass transfer ratio in BioFlo® bioreactors. The proposed correlations may be applied for the design of a scaled-up or scaled-down bioreactors.

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Simulated oxygen and glucose gradients as a prerequisite for predicting industrial scale performance a priori

Kuschel

2020

Biotech & Bioengineering

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Transferring bioprocesses from lab to industrial scale without loss of performance is key for the successful implementation of novel production approaches. Because mixing and mass transfer is usually hampered in large scale, cells experience heterogeneities eventually causing deteriorated yields, that is, reduced titers, productivities, and sugar‐to‐product conversions. Accordingly, reliable and easy‐to‐implement tools for a priori prediction of large‐scale performance based on dry and wet‐lab tests are heavily needed. This study makes use of computational fluid dynamic simulations of a multiphase multi‐impeller stirred tank in pilot scale. So‐called lifelines, records of 120,000 Corynebacterium glutamicum cells experiencing fluctuating environmental conditions, were identified and used to properly design wet‐lab scale‐down (SD) devices. Physical parameters such as power input, gas hold up, , and mixing time showed good agreement with experimental measurements. Analyzing the late fed‐batch cultivation revealed that the complex double gradient of glucose and oxygen can be translated into a wet‐lab SD setup with only few compartments. Most remarkably, the comparison of different mesh sizes outlined that even the coarsest approach with a mesh density of was sufficient to properly predict physical and biological readouts. Accordingly, the approach offers the potential for the thorough analysis of realistic industrial case scenarios.

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Experimental Study of Influence of the Impeller Spacing on Flow Behaviour of Double‐Impeller Stirred Tank

Cited by 4 publications

References 14 publications

Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing

Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing

Hydrodynamics and Mass Transfer Analysis in BioFlow® Bioreactor Systems

Simulated oxygen and glucose gradients as a prerequisite for predicting industrial scale performance a priori

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