6533b86dfe1ef96bd12caa99

RESEARCH PRODUCT

Gas-liquid mass transfer rates in unbaffled tanks stirred by PBT: scale-up effects and pumping direction

Tomáš MouchaRadim PetříčekLibor LabíkFrancesca ScargialiAlberto Brucato

subject

Mass transfer coefficientMaterials scienceViscosityGeneral Chemical EngineeringScale-upChemistry (all)Pitched blade turbineBaffleUnbaffled02 engineering and technologyGeneral ChemistryMechanicsDissipation021001 nanoscience & nanotechnologyImpellerViscosity020401 chemical engineeringMass transferSCALE-UPMass transferChemical Engineering (all)0204 chemical engineering0210 nano-technologyIntensity (heat transfer)Fermenter

description

Abstract Unbaffled stirred tanks are increasingly recognized as a viable alternative to common baffled tanks for a range of applications such as biochemical, food or pharmaceutical processes where the presence of baffles is undesirable for some reason. In this work, the mass transfer performance of unbaffled stirred tanks with pitched blade turbine, operating either in up-pumping or down-pumping mode, was investigated. The influence of impeller size and liquid viscosity were also investigated. The mass transfer intensity was measured by means of the Simplified Dynamic Pressure. Method The measurements concerned both coalescent and non-coalescent (viscous) batches. Results confirm that increasing apparatus size has a slightly positive effect on gas-liquid mass transfer coefficient. It was also found that when the PBT is operating in the up-pumping mode the formation of surface oscillations, which lead to undesired instabilities of the whole apparatus, is conveniently minimized. In the super-critical regime, the unbaffled tanks provide a performance comparable with that of the standard (baffled) bioreactors at the same power dissipation, which makes them a viable alternative for general fermentation operations and other gas–liquid reactions.

yearjournalcountryeditionlanguage
2018-09-01
10.1016/j.cherd.2018.07.006http://hdl.handle.net/10447/295104