Improved oxygen delivery in a continuous-roller-bottle reactor

Berson, R. Eric; Mane, Trupti V.; Svihla, C. Kurt; Hanley, Thomas R.

doi:10.1007/bf02920173

Cited by 3 publications

(2 citation statements)

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“…(1) and (2) to include other physical effects such as swirl, buoyancy or compressibility, for example. The reference values of the model constants were the consensus ones C µ =0.09, C 1 =1.44, C 2 =1.92, σ k =1.0, and σ ε =1.3.…”

Section: The K-ε Mathematical Modelsmentioning

confidence: 99%

“…The process of designing, building and evaluating bioreactors for high-substrate concentration fermentation is both costly and time consuming [1,2]. The use of a computational fluid dynamics (CFD) model can aid in bioreactor development by providing detailed information on the hydrodynamic and chemical environments necessary for optimal hydrolysis and cell growth.…”

Section: Introductionmentioning

confidence: 99%

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A CFD model for predicting the flow patterns of viscous fluids in a bioreactor under various operating conditions

Hanley

2008

Korean J. Chem. Eng.

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Computational fluid dynamics simulation is becoming an increasingly useful tool in the analysis and design of simultaneous saccharification fermentation (SSF) and saccharification followed by fermentation process (SFF). To understand and improve mixing and mass transfer in a highly viscous non-Newtonian system, it was necessary to simulate the flow behavior in this bench scale bioreactor (BioFlo 3000). This study focused on designing a high concentration medium agitation system for such a process using the commercial computational fluid dynamics package Fluent (V. 6.2.20) and its preprocessor Mixsim (V. 2.1.10). The objective of this study is to compare performance of various designs of a bioreactor and identify the flow pattern and related phenomena in the bench scale tank. The configuration of the physical model for simulating a mixing tank with a Rushton impeller consists of an ellipsoidal cylindrical tank with four equally spaced wall mounted baffles extending the vessel bottom to the free surface, stirred by a centrally located six-blade Rushton turbine impeller. Simulations were performed with the original and a modified design in which the lower bottom shaft mounted a Lightnin A200 impeller. The results suggest that there is a potential for slow or stagnant flow between top impellers and bottom of the tank region, which could result in poor nitrogen and heat transfer for highly viscous fermentations. The results also show that the axial velocity was significantly improved for the modified geometry in the bottom of the tank.

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Section: The K-ε Mathematical Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A CFD model for predicting the flow patterns of viscous fluids in a bioreactor under various operating conditions

Hanley

2008

Korean J. Chem. Eng.

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Oxygen mass transfer and scale-up studies in baffled roller bioreactors

Nikakhtari

Song

Nemati

et al. 2013

Bioprocess Biosyst Eng

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Oxygen mass transfer was studied in conventional, bead mill and baffled roller bioreactors. Using central composite rotational design, impacts of size, rotation speed and working volume on the oxygen mass transfer were evaluated. Baffled roller bioreactor outperformed its conventional and bead mill counterparts, with the highest k(L)a obtained in these configurations being 0.58, 0.19, 0.41 min(-1), respectively. Performances of the bead mill and baffled roller bioreactor were only comparable when a high bead loading (40%) was applied. Regardless of configuration increase in rotation speed and decrease in working volume improved the oxygen mass transfer rate. Increase in size led to enhanced mass transfer and higher k(L)a in baffled roller bioreactor (0.49 min(-1) for 2.2 L and 1.31 min(-1) for 55 L bioreactors). Finally, the experimentally determined k(L)a in the baffled roller bioreactors of different sizes fit reasonably well to an empirical correlation describing the k(L)a in terms of dimensionless numbers.

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