0585697 - ÚH 2025 CZ eng C - Conference Paper (international conference)
Gebouský, Ondřej - Haidl, Jan - Bodnár, J. - Pivokonský, Martin
Improvement of an unbaffled stirred tank mixing characteristics using variable speed impeller.
Topical Problems of Fluid Mechanics. Prague: Institute of Thermomechanics AS CR, v. v. i., 2024 - (Šimurda, D.; Bodnár, T.), s. 54-60. ISBN 978-80-87012-88-8. ISSN 2336-5781.
[Topical Problems of Fluid Mechanics 2024. Prague (CZ), 21.02.2024-23.02.2024]
Grant - others:AV ČR(CZ) StrategieAV21/20; AV ČR(CZ) AP2201
Program: StrategieAV; Akademická prémie - Praemium Academiae
Institutional support: RVO:67985874
Keywords : unbaffled mixing tanks * variable rotational speed * vortex destabilization * mixing time improvement
OECD category: Chemical engineering (plants, products)
http://www2.it.cas.cz/fm/im/im/proceeding/2024/8

Unbaffled mixing tanks with magnetically driven impellers are increasingly used in biotechnological and pharmaceutical industries, combining the benefits of a closed, sterile environment with easy equipment cleanability. On the other hand, missing internals, such as baffles or cooling coils, have an adverse effect on the equipment mixing characteristics, namely the batch
homogenization time. In our previous research, we uncovered that the eccentricity and inclination of the impeller – both employed routinely to enhance the mixing characteristics of unbaffled vessels – are not fully effective in the suppression of central vortex formation resulting in the increase in the homogenization time. In this work, we propose a simple solution to counteract the central vortex formation – a periodical variation of impeller rotational speed. This approach destabilizes the central vortex, significantly reducing homogenization time while maintaining the benefits of the original unbaffled setup. This innovation can seamlessly integrate into existing industrial setups, promising efficiency gains for biotech and pharmaceutical production.
Permanent Link: https://hdl.handle.net/11104/0353398