Applied Microbiology and Biotechnology

, Volume 27, Issue 2, pp 159–167

Influence of antifoam agents on gas hold-up and mass transfer in bubble columns with non-newtonian fluids

  • Y. Kawase
  • M. Moo-Young
Biotechnology

Summary

Experimental studies on the effect of antifoam agents on the performance of bubble columns with non-Newtonian fluids have been conducted. It is found that the gas hold-up and volumetric mass transfer coefficient in the case of water were reduced due to the addition of antifoam agents. It was found that this decrease in volumetric mass trasfer coefficient is substantial but in the aqueous solutions of polymers the effect becomes weaker as the concentration of polymers becomes higher. When the concentration of polymers became higher than a certain value, the volumetric mass transfer coefficient in the aqueous solutions of polymers with antifoam agents was higher than that without antifoam agents.

Nomenclature

a

Specific surface area, 1/m

Dc

Column diameter, m

dmax

Diameter of the largest bubble stable against breakup, m

dmin

Diameter of the smallest bubble stable against coalescence, m

g

Gravitational acceleration, m/s2

Hl

Clear liquid height, m

h

Rupture thickness of the liquid film, m

K

Consistency index in a power-law model, Pa·sn

kl

Liquid-phase mass transfer coefficient, m/s

n

Flow index in a power-law model

usg

Superficial gas velocity, m/s

Greek letters

γ

Shear rate, 1/s

ε

Gas hold-up

\(\bar \varepsilon \)

Energy dissipation per unit mass, m2/s3

μ

Viscosity, Pa·s

p

Density, kg/m3

δ

Surface tension, N/m

τ

Shear stress-Pa

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Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • Y. Kawase
    • 1
  • M. Moo-Young
    • 1
  1. 1.Department of Chemical EngineeringUniversity of WaterlooWaterlooCanada

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