The following expression for the efficiency of a
fractionating column was given as

Comment on the appropriateness of each variable. Can any of
the variables or groups of variables be eliminated? The data used to obtain the
above expression were based on seven different articles in the literature.

µ_L = liquid viscosity, poise

P_L = liquid density, g/cc

D_L = liquid diffusivity, cm²/sec

 = interfacial tension, dynes/em

 = relative volatility, dimensionless
1.6-20.8

A = fraction free area, dimensionless 0.041-0.125

 = reflux ratio, dimension less
0.83-70

h = height, in. 0.25-5

G = gas velocity based on column

crossection, Ib/(hr)(ft²) 100-2000