Inner-Pipe Structure to Improve Column Heterogeneity and Peak Shape

Column heterogeneity plays an important role in peak tailing and asymmetric profiles. We have designed a novel column structure (concentric column structure) that has a concentric inner-pipe nested in a column. This structure was studied by a number calculation method and wider diameter column experiments. The results showed that column heterogeneity and column efficiency were improved by inner-pipe structure. Moreover, the results showed that high-efficiency columns were stronger influenced by inner-pipe structure than low-efficiency columns. The influence of an inner-pipe was related to its size. The optimal inner-pipe diameter was nearly 0.625 times of column diameter. By using inner-pipe structure in this way, it was possible to decrease column heterogeneity and increase column efficiency of a wide-diameter column.