H₂-HT Separation Using "Cryogenic-Wall" Thermal Diffusion Column with Heated-Tube

The pressure dependence of separation factors of the columns for H₂-HT mixture was measured for practical design of "cryogenic-wall" thermal diffusion columns for tritium handling system. Experiments were performed with 1,020 mm-height column with a 4.8 mm-outer-radius tube heated by hot-water and a 11.5 mm-inner-radius tube cooled by liquid nitrogen. The maximum total separation factor was 12.7 at 80 kPa for H₂-HT separation. By using another column with 9.53 mm-outer-radius tube heated by hot-water and a 14.2 mm-inner-radius tube, the separation factor was 64.4 at 144 kPa, and the separation will be larger at higher pressure.

Comparison of numerical calculations of axial and radial two-dimensional flow and concentration distribution with experimental data revealed that our code could predict the pressure dependence of separation factor of the columns well.