Estimation de I'Influence du Mode d'Ecoulement du Gaz sur le Facteur de Separation d'une Colonne de Diffusion Thermique

Abstract

The transport equation relevant to the heavier of two elements forming a gaseous mixture was derived from the following equations.
Heat balance: d²T/dr²+(1/r)•(dT/dr)=0
Material balance: d²υ_z/dr²+(1/r)•(dυ_z/dr)=α•(T-T_c)
Diffusion equation concerning the heavier element:
∂(rJ_c)∂z+∂(rJ_DZ)/∂z+∂(rJ_DR)+∂(rJ_TD)/∂r=0
Concentration of the heavier element in the radial direction:
C₁(r, z)=C₁(R_i, z)+(r-R_i)K₁.
The transport equation thus derived became that of Jones & Furry when the smaller terms were neglected.
The influence on the separation factor brought by the axial gas velocity υi along the hot wire surface was then analyzed. The results were as follows:
The maximum separation factor displaces toward lower operating pressures when the gas velocity υ_i is increased to a certain degree. It would appear from the present calculation that to obtain maximum separation, lower operating pressures should be combined with higher gas velocity υ_i, while with increasing operating pressure, υt, should have to be gradually reduced, finally to reach zero at a certain pressure.