A d
down-comer cross-sectional area
A r
riser cross-sectional area
C P
protein concentration in feed
C R
protein concentration in residue liquid
C S
protein concentration in foam liquid
C P *
cell concentration in feed
C R *
cell concentration in residue liquid
C S *
cell concentration in foam liquid
D
dilution rate in reactor
E
protein enrichment factor (Eq. 6)
E *
cell enrichment factor (Eq. 13)
f q
signal activity coefficient
g
acceleration of gravity
H
foam height
k L a
volumetric mass transfer coefficient of oxygen
m corr coalescence index (Eq. 3)
N
stirrer speed
P
pr od uct concen tra tion
q G
aeration rate of the reactor
R
protein recovery (Eq. 8)
R *
cell recovery (Eq. 15)
S
protein separation factor (Eq. 7)
S *
cell separation factor (Eq. 14)
SG
specific glucose uptake rate
SP
specific product concentration with regard to the cell mass
t
ti m e
u
drainage velocity of Plateau borders
V tP
volumetric flow rate of feed
V tS
volumetric flow rate of foam liquid
V tR
volumetric flow rate of residue liquid
V S
equilibrium volume of the foam above the liquid layer
v B
actual bubble velocity
v B0
original bubble velocity
V tg
volumetric gas flow rate
w SG
superficial gas velocity in the flotation column
x
antifoam concentration
X
(dry) cell mass concentration
Y X/S
yield coefficient of growth with respect to substrate consumed
e
liquid holdup
G
surface concentration of protein
m
specific growth rate
m P
viscosity of protein solution
Ç
density of protein solution
S
foaminess for batch operation (Eq. 1)
S *
foaminess for continuous operation (Eq. 10)
s
surface tension
s o
volumetric concentration of AFA
Recovery of Proteins and Microorganisms from Cultivation Media by Foam Flotation
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