Page 88 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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2
Di- diffusivity for the liquid phase, m /s;
2
D G - axial mixing coefficient for the gas phase, m /s;
2
D L - axial mixing coefficient for the liquid phase in m /s;
D a = 6(1 — e) / a - arithmetical hydraulic diameter of the packing, m;
d- diameter of the packing elements or other characteristic geometrical value of
the packing, m;
dt - bubble diameter, m;
d e = 4 e/a- equivalent (hydraulic) packing diameter, m;
dp- packing size, m;
dt
temperature gradient, K/m;
dn
Ed=z£iJL -Edtvos number;
a a
2
F - mass transfer area in m ;
:
Fr L = — — Froude number for the liquid phase;
g
F G = WQ^PG - vapour (gas) capacity factor, without taking into account the
1
liquid density, kg^m'^s" ;
w
F"w- aJ— vapour (gas) capacity factor, taking into account the

liquid density, m/s;
s0
/ = se~ - function depending on the distribution of the contact time;
2 2
G - mass of the transferred substance, kg/m s or mol /m s;

Ga L = —z— Galilei number for the liquid phase;
n
2
Gj- mol flow of liquid phase, kmol/(m .s);
2
G r- mol flow of gas phase, kmol/(m .s);
G g — mass flow rates of the gas phase, kg/s;
G m - mol flow rates of the gas phase, kmol/s;
2 1
G m - mol velocities of the gas phase, kmol. m" . s" ;
2
Gk - mass flow of the dry gas - kg/(m .s);
g- gravity constant, m/s ;
H- packing height, m;