Effect of Cold Wall Temperature of Thermal Diffusion Column on¹⁴N¹⁵N—¹⁴N₂Isotope Separation

Abstract

The effect of cold wall temperature on separative performances for 14 N 15 N-14 N 2 separation was studied with the thermal diffusion column of an effective height of 950 mm, a hot wire of 0.15 mm in radius and a cold wall of 5.0 mm in radius. The column was maintained at a constant pressure 0.1 MPa with feed flow rate of 10 cm 3 -min-1 (at 0.1 MPa and 298.15 K). The temperature of the cold wall was changed from 223 to 283 K by 20 K keeping at the same temperature difference 235 K between the hot and cold walls. The total separation factor became larger as the cold wall temperature decreased, but had almost the same value at 223 K and 243 K. The experimentally obtained separation factors were compared with the results of the numerical analyses of a convection-diffusion equation. The solutions of numerical analyses with thermal diffusion factor incorporated with inelastic effect gave a good reproduction of dependence of separation factors on cut and cold wall temperature rather than those without inelastic effect. The discrepancy between experimental and analytical results, however, became larger as the cold wall temperature decreased.