Critical impeller speed for complete gas-liquid dispersion for various impeller types

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F21%3A43923790" target="_blank" >RIV/60461373:22340/21:43923790 - isvavai.cz</a>

Výsledek na webu

<a href="http://sschi.chtf.stuba.sk/data/full_papers/320.pdf" target="_blank" >http://sschi.chtf.stuba.sk/data/full_papers/320.pdf</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Critical impeller speed for complete gas-liquid dispersion for various impeller types

Popis výsledku v původním jazyce

Stirred tank reactors are widely used in various chemical and biochemical technologies. In the case of bioreactors, the effectiveness of aerobic fermentation is mostly controlled by two opposing processes – maximization of the oxygen mass transfer rate and minimization of the shear-stress damaging the microorganism cultures. The knowledge of critical conditions ensuring the sufficient supply of oxygen and simultaneously minimalizing the damaging of microorganisms is crucial for the successful design and scale-up of the bioreactor. The aim of the contribution is to obtain the critical impeller speed for the complete dispersion of various impeller types in stirred tank reactors of two sizes (0.29 and 0.59 m inner diameter). Four impeller types are used: Rushton turbine (RT, radial impeller), pitched blade impeller (PBD), Techmix 335 (TXD), and Lightnin A315 (LTN, all axial impellers pumping down). The critical impeller speed is obtained from the dependence of power number on gas flow number under aerated conditions. The used liquid phases are distilled water (coalescent batch), 0.5M Na2SO4 solution (non-coalescent batch) and 1.2 %(wt) solution of commercial thickener Sokrat 44 (viscous non-coalescent batch). The critical impeller speed of radial impeller (RT) is smaller in comparison with axial impellers. This suggests the more intense mixing and dispersion production for radial impeller but simultaneously higher shear stresses which would damage the microorganism culture.

Název v anglickém jazyce

Critical impeller speed for complete gas-liquid dispersion for various impeller types

Popis výsledku anglicky

Stirred tank reactors are widely used in various chemical and biochemical technologies. In the case of bioreactors, the effectiveness of aerobic fermentation is mostly controlled by two opposing processes – maximization of the oxygen mass transfer rate and minimization of the shear-stress damaging the microorganism cultures. The knowledge of critical conditions ensuring the sufficient supply of oxygen and simultaneously minimalizing the damaging of microorganisms is crucial for the successful design and scale-up of the bioreactor. The aim of the contribution is to obtain the critical impeller speed for the complete dispersion of various impeller types in stirred tank reactors of two sizes (0.29 and 0.59 m inner diameter). Four impeller types are used: Rushton turbine (RT, radial impeller), pitched blade impeller (PBD), Techmix 335 (TXD), and Lightnin A315 (LTN, all axial impellers pumping down). The critical impeller speed is obtained from the dependence of power number on gas flow number under aerated conditions. The used liquid phases are distilled water (coalescent batch), 0.5M Na2SO4 solution (non-coalescent batch) and 1.2 %(wt) solution of commercial thickener Sokrat 44 (viscous non-coalescent batch). The critical impeller speed of radial impeller (RT) is smaller in comparison with axial impellers. This suggests the more intense mixing and dispersion production for radial impeller but simultaneously higher shear stresses which would damage the microorganism culture.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20401 - Chemical engineering (plants, products)

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

PROCEEDINGS 47th International Conference of the Slovak Society of Chemical Engineering

ISBN

978-80-8208-057-8

ISSN

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e-ISSN

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Počet stran výsledku

8

Strana od-do

1-8

Název nakladatele

Vydavateľstvo STU v Bratislave

Místo vydání

Bratislava

Místo konání akce

Bratislava

Datum konání akce

18. 5. 2021

Typ akce podle státní příslušnosti

EUR - Evropská akce

Kód UT WoS článku

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