Multiphase Bioreactor Design

velocity corresponding for particular plate geometry to the onset of its stable and uniform
distributing performance, characterised by the critical value of Weber number, (Wen)crit =
[(uoG)crit^2 ρG dn/φ^2 σ]=3, determined experimentally in our former study (Zahradník et al.,
1982b). For the plates used in the present study (φ=0.0025, dn=0.0018 m) and air-water
system, (uoG)crit equals to 0.025 m s−^1.

Table 1.1 Liquid holdup in the staged bubble

column (cs=0)

VL

m^3

(^) N=
uoL,
3 m/s^ N=
uoL,
uoG 6 m/s^
m/s
0 0.004 0.008 0.012 0.017 0.029 0 0.004 0.008 0.012 0.017 0.029
0.025 0.099 0.100 0.101 0.101 0.102 0.106 0.096 0.095 0.095 0.096 0.097 0.101
0.033 0.098 0.099 0.099 0.100 0.101 0.105 0.091 0.092 0.092 0.093 0.094 0.097
0.042 0.096 0.097 0.098 0.098 0.099 0.103 0.087 0.088 0.088 0.089 0.090 0.094
0.050 0.094 0.094 0.095 0.096 0.097 0.100 0.081 0.082 0.082 0.083 0.084 0.088
0.058 0.091 0.091 0.092 0.093 – – 0.074 0.075 0.075 0.076 – –

Table 1.2 Average value of liquid backflow

coefficient in multistage bubble columns

a) This work: Dr=0.292 m,=0.25%, dn=1.8 mm

uoL
m/s

uoG

m/s

E

N=3

v

N=6

0.025 0.34 0.28

0.033 0.52 0.49

0.042 0.75 0.61

0.050 1.09 1.14

0.004

0.058 1.92 1.89

0.025 0.04 0.04

0.033 0.13 0.06

0.042 0.17 0.11

0.050 0.22 0.30

0.010

0.058 0.32 0.55

0.013 0.025 0.03 0.02

0.033 0.05 0.04

New methodologies for multiphase bioreactors 1 7