Experimental Verification of the Thermal Diffusion Column Theory as Applied to the Separation of Isotopically Substituted Nitrogen and Isotopically Substituted Oxygen

Abstract

By means of techniques previously developed, column transport coefficients were measured for the ¹⁴N¹⁴N–¹⁴N¹⁵N and ¹⁶O¹⁶O–¹⁶O¹⁸O separations in a 7.32‐m hot‐wire thermal diffusion column at wire temperatures of 500° and 800°C. These data and several sets of column data from the recent literature were compared with predicted values calculated from the Jones and Furry theory with integrations based on carefully selected tables of smoothed transport properties. On the basis of measurements for nitrogen reported in the literature it was assumed that the isotopic thermal diffusion factors for both gases were 0.7 times the value given by the Lennard‐Jones potential. Good agreement was obtained between theory and experiment. The average ratios of the measured values of the column coefficients to the corresponding predicted values were found to be unity within essentially twice the standard deviation of the experimental determinations. There were negligible differences between column coefficients calculated from tabulated transport properties and those calculated from Lennard‐Jones shape factors.