抄録
By using the two-dimensional rigorous numerical solution of flow and convection-diffusion equations, the 3He-4He separative performances of 0.3 mmφ hot-wire thermal diffusion column with 1, 500 mm-height, 15 mm-radius cold-wall was analyzed with pressure P, cold wall tempera-ture Tc and feed rate F being parametrically changed, while the temperature difference between hot wire and cold wall being constant 1, 200 K. Separative analysis using the Dymond-Alder potential for the cryogenic-wall (less than 77.35 K) column has revealed in comparison with the ordinary 288 K cold-wall column with the same condition except Tc that : (i) The degree of separation is remarkably larger and the total separation factor αβ exceeds 105 (at 0.020 MPa) when Tc=10 K, F=1 cm3 (converted at 288.15 K, 0.1 MPa)/min and θ=0.1, while αβ=13 (at 0.148 MPa) for Tc=288 K. (ii) Even for the higher feed rate F of 50 cm3/min, αβ remains 2.1 ×103 (at 0.024 MPa), while αβ=7 (at 0.170 MPa) for Tc-=288 K. In addition, (iii) Pressure dependence of the total separation factor given for the column with continuous feed and draw-offs were found to follow the similarity relation derived for the total reflux operation.
