Heavy water enrichment in wired concentric-tube thermal-diffusion columns with transverse sampling streams

The equations which may be employed to predict the optimum wire angles of i nclination for enrichment of heavy water in a concentric-tube thermal-diffu sion column with a tight fitting wire spiral, having a diameter equal to th e annular spacing, wrapped on the entire inner tube, operating with transve rse sampling streams, have been derived. Considerable improvement in perfor mance is obtainable if wire. spiral is employed in the column at the optimu m angle, instead of the absence of wire spiral, so that the convection stre ngth can be properly reduced and controlled, resulting in suppressing the u ndesirable remixing effect while still preserving the desirable cascading e ffect. Accordingly, essential savings in fixed charges and operating expens e can be achieved, particularly for lower production rate operations or for smaller degree of separation.