Effect of the Cold-Wall Temperature on the Separative Performance of a “Cryogenic-Wall” Thermal Diffusion Column for H₂-HT Isotope Separation

Abstract

The present paper analyzes the separative performance of a “cryogenic-wall” thermal diffusion column of which the cold-wall temperature is lower than 77.35 K. Because the value of thermal diffusion factor α_T for H₂-HT mixture decreases in lower temperature region and is probably negative under ∼70 K, an estimated enhancement of the separation factor is not so large: the total separation factor (αβ)_max of the column with r_h = 0.015 cm, r_c = 1.5 cm, Z = 150 cm and ΔT = 1200 K increases from ∼3.3×10³ (T_c = 77.35 K, P_opt = ∼0.04 MPa) to ∼6.0×10³ (T_c = 30 K, P_opt = ∼0.027 MPa) when the column is operated under the feed rate of 10 cm³(converted to the value of 0.1 MPa and 288.15 K)/min and the cut θ is 0.1.