The best column number in the countercurrent-flow Frazier scheme for deuterium recovery from water-isotopes mixture by thermal diffusion with total sum of column height fixed

The effect of column number on thermal diffusion in the countercurrent-flow Frazier scheme with total sum of column heights (L = Nh) fixed, has been investigated. The equations, which may be employed to predict the proper column number for the best performance are derived. Considerable improvement in performance is obtainable if the scheme is constructed with the proper number of thermal diffusion columns, instead of using a single column with column height L (N = 1, h = L). This is because that increasing the column height in a thermal diffusion column though increases the effective separation section, the increment in performance with the increase of column height will decrease, and finally the separation efficiency reaches a limiting value.