ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Gas holdups (∊GR) and liquid-phase volumetric oxygen transfer coefficients (kLaT) were measured for a bubble column (BC) and three different external-circulation-loop airlift (ECL-AL) fermentors of 50 to 60 L working volume, using viscous non-Newtonian aqueous solutions of various carboxymethylcelluloses. Some measurements also were done with a viscous Newtonian system (51.8 wt. % sucrose solution).Discussed in this paper are correlations of ∊GR and kLaT with riser superficial gas velocity (0.02 ≦ UGR ≦ 0.26 m/s), the ratio of the downcomer and riser crosssectional areas (0[BC] ≦ Ad/Ar ≦ 0.444), and the effective viscosity of the liquid phase (0.02 ≦ ηeff ≦ 0.5 Pa · s), over the parameter ranges indicated. It is shown that both ∊GR and KLaT are highly dependent upon UGR and Ad/Ar. The effective viscosity has a significant effect on KLaT, but has only a relatively weak affect on ∊GR. The KLaT correlation developed for non-Newtonian systems was extended to include the results obtained for the viscous Newtonian system studied by incorporating the effects of liquid-phase molecular diffusivity, density, and interfacial tension as determined by Nakanoh and Yoshida (1980).
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690350307
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