Page 89 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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HTU X = —— height of one mass transfer unite, calculated for the liquid

phase, m;

HTU Y = —- — height of one mass transfer unite, m;
K rM e
3
3
Hj - dynamic liquid holdup, m /m ;
3 3
Hat - liquid holdup under the loading point, m /m ;
3
Hk - liquid holdup of the packing, m /m ;
3
H s - static liquid holdup of the packing, mVm ;
He- Henry constant, Pa;
HETP - height equivalent to one theoretical stage (theoretical plate);
HETPx - height equivalent to one theoretical stage {theoretical plate) for the
liquid phase;
HETPY - height equivalent to one theoretical stage (theoretical plate) for the gas
phase;
3
3
H h - liquid holdup, m /m ;
3
3
H s - static liquid holdup m /m ;
h- packing height, current coordinate, m;
a - index for the absorbed component;
2
K- overall heat transfer coefficient, W/(m °C);
KG- overall mass transfer coefficient for the gas phase, m/s;
2
2
Ky overall mass transfer coefficient for the gas phase, kg/(s,m ) or kmol/(s.m );
K Ga = K G.a e - volumetric mass transfer coefficient for the gas phase, 1/s;
Ki~ overall mass transfer coefficients for the liquid phase, m/s;
2
K x- overall mass transfer coefficients for the liquid phase, kg/(s.m ) or
2
kmol/(s.m );
K La = K L.a e - volumetric mass transfer coefficient for the liquid phase, 1/s;
Kg- coefficient of radiation of an absolutely black body;
her partial mass transfer coefficient, for the gas phase, m/s;
k L- partial mass transfer coefficient for liquid phase, m/s;
2
3
L- liquid, superficial velocity in m /(m s);
£/, L 2, L3 L m - geometrical sizes, m;
L g - flow rates of the liquid phase in kg/s;
Zga, - mol flow rates of the liquid phase in kmol/s;
2 1
L m - mol velocities of the liquid phase, kmol m" . s" ;
la - ratio between the molar flow rates of the liquid and of the gas phase;
//, I2,13, 4-geometrical sizes, m;
M L -mol mass of the liquid phase;