Liquid Homogenization in Aerated Multi-Impeller Stirred Vessel

Machoň, Václav; Jahoda, M.

doi:10.1002/1521-4125(200010)23:10<869::aid-ceat869>3.0.co;2-b

Cited by 27 publications

(32 citation statements)

References 5 publications

(9 reference statements)

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“…The mixing pattern and times show essential differences. For Rushton turbines the mixing occurs in segments from top-to-bottom as described by other authors (Jahoda and Machon 1994;Machon and Jahoda 2000). A clear axial flow is visible and the last point of mixing occurs at the top in the three pitched blade-impeller system operated in the downpumping mode.…”

Section: Mixingsupporting

confidence: 81%

Equipment characterization to mitigate risks during transfers of cell culture manufacturing processes

2015

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The production of monoclonal antibodies by mammalian cell culture in bioreactors up to 25,000 L is state of the art technology in the biotech industry. During the lifecycle of a product, several scale up activities and technology transfers are typically executed to enable the supply chain strategy of a global pharmaceutical company. Given the sensitivity of mammalian cells to physicochemical culture conditions, process and equipment knowledge are critical to avoid impacts on timelines, product quantity and quality. Especially, the fluid dynamics of large scale bioreactors versus small scale models need to be described, and similarity demonstrated, in light of the Quality by Design approach promoted by the FDA. This approach comprises an associated design space which is established during process characterization and validation in bench scale bioreactors. Therefore the establishment of predictive models and simulation tools for major operating conditions of stirred vessels (mixing, mass transfer, and shear force.), based on fundamental engineering principles, have experienced a renaissance in the recent years. This work illustrates the systematic characterization of a large variety of bioreactor designs deployed in a global manufacturing network ranging from small bench scale equipment to large scale production equipment (25,000 L). Several traditional methods to determine power input, mixing, mass transfer and shear force have been used to create a data base and identify differences for various impeller types and configurations in operating ranges typically applied in cell culture processes at manufacturing scale. In addition, extrapolation of different empirical models, e.g. Cooke et al. (Paper presented at the proceedings of the 2nd international conference of bioreactor fluid dynamics, Cranfield, UK, 1988), have been assessed for their validity in these operational ranges. Results for selected designs are shown and serve as examples of structured characterization to enable fast and agile process transfers, scale up and troubleshooting.

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Section: Mixingsupporting

confidence: 81%

Equipment characterization to mitigate risks during transfers of cell culture manufacturing processes

2015

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“…The simplest structured hydrodynamic model is based on a rough compartimentalisation of the bioreactor in a few virtual fluid zones. This kind of model has been used with success to characterize axial concentration gradient in multiimpeller systems (Mayr B., 1993, Machon V., 2000, Cui Y.Q., 1996, Vasconcelos J.M.T., 1995. The advantage of such model relies on its simple physical and mathematical representation, i.e.…”

Section: Simulation Of the Concentration Gradient Fields Inside Biorementioning

confidence: 99%

Applicability of GFP Microbial Whole Cell Biosensors to Bioreactor Operations - Mathematical Modeling and Related Experimental Tools

Delvigne

Brognaux²,

Gorret³

et al. 2011

Biosensors - Emerging Materials and Applications

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“…Axial‐flow impellers such as pitched blade turbines can provide a good balance between the generated shear and bulk flow . Therefore, axial‐flow impellers have advantage over radial ones in aerated systems . It was demonstrated that the up‐pumping mode of axial impellers is better than the down‐pumping mode with regard to power and torque instabilities in the presence of gas .…”

Section: Introductionmentioning

confidence: 99%

“…18,19 Therefore, axial-flow impellers have advantage over radial ones in aerated systems. [18][19][20][21][22] It was demonstrated that the up-pumping mode of axial impellers is better than the down-pumping mode with regard to power and torque instabilities in the presence of gas. 20,23,24 These results are in good agreement with those obtained in our previous work.…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamic characteristics of an aerated coaxial mixing vessel equipped with a pitched blade turbine and an anchor

Hashemi

Ein‐Mozaffari

Upreti

et al. 2017

J of Chemical Tech & Biotech

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Background In this work, computational fluid dynamics (CFD) simulation of an aerated coaxial mixing vessel composed of a centered impeller and a wall scraping anchor was conducted to investigate the effects of speed ratio, rotation modes (co‐rotating and counter‐rotating), and fluid viscosity on the local and global gas holdup values, flow pattern within the vessel, and turbulent kinetic energy. To validate the developed model, simulated gas holdup and gassed power uptake were compared with the measured experimental values. To gather experimental gas holdup values, an electrical resistance tomography technique was utilized. Results The results demonstrated that the co‐rotating coaxial mixer with a speed ratio higher than 10 provided a higher gas volume fraction within the vessel. It was also shown that the turbulent kinetic energy attained in the counter‐rotating mode was lower than those for the co‐rotating coaxial mixer in most regions within the mixing tank, especially near the vessel walls. The size and the number of circulation loops developed within the coaxial mixer were affected by the speed ratio. Conclusion It was demonstrated that speed ratio and rotation mode of the impellers affected the hydrodynamics developed within the aerated coaxial mixer. © 2017 Society of Chemical Industry

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Liquid Homogenization in Aerated Multi-Impeller Stirred Vessel

Cited by 27 publications

References 5 publications

Equipment characterization to mitigate risks during transfers of cell culture manufacturing processes

Equipment characterization to mitigate risks during transfers of cell culture manufacturing processes

Applicability of GFP Microbial Whole Cell Biosensors to Bioreactor Operations - Mathematical Modeling and Related Experimental Tools

Hydrodynamic characteristics of an aerated coaxial mixing vessel equipped with a pitched blade turbine and an anchor

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