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Aeration and mixing in vortex fermenters
Author(s) -
Chisti Yusuf,
MooYoung Murray
Publication year - 1993
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280580404
Subject(s) - mixing (physics) , aeration , vortex , mechanics , environmental science , physics , thermodynamics , biology , ecology , quantum mechanics
The overall apparent volumetric gas—liquid mass transfer coefficient ( k 95 a ) and the mixing time ( t 95 ) were determined in a 240 dm 3 vortex aerated fermenter over stirrer speed and air flow ranges of 300–800 rpm and 10–45 normal dm 3 min −1 , respectively. The mass transfer data obtained in an aqueous salt solution (2.5 kg m −3 NaCl in water) compared well with the measurements in a fermentation medium used in culture of certain microaerophilic bacteria. Over the ranges examined, the gas‐liquid mass transfer coefficient depended only on air flow rate; the dependence was linear with flow. Mixing time declined with increasing agitation according to a power‐law relationship. The mixing and mass transfer characteristics of the vortex aerated system were compared with that of a ‘standard’ stirred tank fermenter (27 dm 3 ). The mixing time variations with respect to agitation rate were remarkably similar for the two types of fermenters examined.