Bioprocess Engineering

, Volume 9, Issue 2, pp 61–75

Oxygenation of cell cultures

Authors

  • H.-J. Henzler
    • Zentrale Forschung/Bioverfahrenstechnik BAYER AG
  • D. J. Kauling
    • Zentrale Forschung/Bioverfahrenstechnik BAYER AG
Originals

DOI: 10.1007/BF00369033

Cite this article as:
Henzler, H. & Kauling, D.J. Bioprocess Eng. (1993) 9: 61. doi:10.1007/BF00369033

Abstract

Submersed cultures are increasingly being used for fermentation with animal cells. Reactor design is particularly important in these operations, because of the sensitivity of the cells to shear. In addition to the usual aeration methods, open-pore membranes or pure diffusion membranes are used for oxygenation in order to avoid gas bubbles. The various oxygenation methods are described in the present article [1]. Design principles for surface aeration, bubble columns, loop reactors, and stirred tanks, as well as oxygenation with Accurel or silicone membranes, are presented and discussed specifically for the low oxygen inputs desired in cell cultures. The scale laws are formulated, and special reference is made to problems of scale up. The various oxygenation methods are finally compared on the basis of the design principles presented, with particular attention to mechanical stress on the cells and to the laws of scale translation.

List of Symbols

A

Interfacial area

a

=A/V, Specific interfacial area

c*

Saturation concentration

c

Gas concentration in the liquid phase

d

Impeller diameter

d2

Outside diameter of tubular membrane

d1

Inside diameter of tubular membrane

d

Diameter under stretched conditions

dp

Particle diameter

dL

Diameter of sparger holes

D

Reactor diameter

DL

Draught tube diameter

\(\mathbb{D}\)

Gas/liquid diffusion coefficient

e

Eccentricity

Fr

Froude number

G

Mass flow

g

Acceleration due to gravity

h

Height of impeller blade

H

Filling height

Hy

Henry constant for the liquid phase

Hys

Henry constant of the membrane material

k

Overall mass transfer coefficient

kL

Gas-liquid interface mass transfer coefficient

L

Length of the tubular membrane

L

Length of the streched turbulare membrane

n

Impeller speed

Ne

P/ϱ n3d5, Newton number

\(\mathcal{P}{\text{o}}_{\text{2}} \)

O2-partial pressure in the membrane

\({\text{(}}\mathcal{P}{\text{o}}_{\text{2}} )_R \)

O2-partial pressure in the reactor

P

Impeller power

q

Gas throughput

r

Cell specific respiration rate

Re

Reynolds number

Sc

\(v/\mathbb{D}\), Schmidt number

Sh

\(/\mathbb{D}\), Sherwood number

u

Liquid velocity

\(\sqrt {u'^2 } \)

Root mean square velocity of turbulent fluctuations Superficial gas velocity

V

Filled reactor volume

Vs

Sparged volume

X

Cell concentration

ɛ

Energy dissipation

η

Dynamic viscosity

ϑ

Temperature

ν

Kinematic viscosity

ϱ

Density of the liquid

σ

Surface tension

τ

Shear stress

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Copyright information

© Springer-Verlag 1993