Modeling of correlations for stirred tank bioreactor agitated with atypical helical ribbon impeller

Mohamed, Mohd S. and Mohamad, Rosfarizan and Ramakrishnan, N. Ramanan and Manan, Musaalbakri A. and Ariff, Arbakariya (2009) Modeling of correlations for stirred tank bioreactor agitated with atypical helical ribbon impeller. American Journal of Applied Science, 6 (5). pp. 848-856. ISSN 1546-9239

Full text not available from this repository.

Abstract

Problem Statement: Mixing filamentous fungi entails delicate balance between promoting high volumetric oxygen transfer coefficient (kLa) while keeping low hydrodynamic stresses in the microenvironment of cultures. This study examined the oxygen transfer capability of a prototype low shear helical impeller as a potential replacement for the standard Rushton turbine. Approach: The dependence of kLa upon specific power uptake, superficial gas velocity and apparent viscosity were examined under coalescent, non-coalescent and viscous pseudoplastic fluids scenario using dynamic gassing out technique. Subsequently, collected data were treated under historical data design of response surface methodology. Results: Three empirical power law kLa correlations were developed for each fluid. Correlation comparison with literature models for single turbine agitation suggest higher kLa augmentation within 1.5-3.6 folds for helical impeller in distilled water and as high as 78% improvement in electrolytes fluid. However impeller performance is comparatively 10% lower against theoretical kLa of triple turbines arrangement for power uptake between 0-1600 W m-3. In case of carboxymethylcellulose, better oxygen transfer is expected for design with higher proportionality of impeller-to-tank internal diameter. Conclusions: Helical impeller performance as gas-liquid contactor is comparable to single and triple Rushtons turbines, with superficial gas velocity proved to be more influential than power uptake in non-viscous liquids and vice versa in viscous pseudoplastic fluids.

Item Type:Article
Keyword:Oxygen transfer; Impeller; Stirred Tank Bioreactor; Response Surface Methodology
Subject:Bioreactor
Subject:Response surfaces (Statistics)
Faculty or Institute:Faculty of Biotechnology and Biomolecular Sciences
Publisher:Science Publications
DOI Number:DOI: 10.3844/ajassp.2009.848.856
ID Code:15664
Deposited By: Nida Hidayati Ghazali
Deposited On:24 Jul 2012 01:39
Last Modified:31 Oct 2012 03:13

Repository Staff Only: item control page

Document Download Statistics

This item has been downloaded for since 24 Jul 2012 01:39.

View statistics for "Modeling of correlations for stirred tank bioreactor agitated with atypical helical ribbon impeller"


Universiti Putra Malaysia Institutional Repository

Universiti Putra Malaysia Institutional Repository is an on-line digital archive that serves as a central collection and storage of scientific information and research at the Universiti Putra Malaysia.

Currently, the collections deposited in the IR consists of Master and PhD theses, Master and PhD Project Report, Journal Articles, Journal Bulletins, Conference Papers, UPM News, Newspaper Cuttings, Patents and Inaugural Lectures.

As the policy of the university does not permit users to view thesis in full text, access is only given to the first 24 pages only.