| 摘要 |
<p>An assembly for use in an exchange column includes a first layer of packing (22; 33) with an edge (12; 13) modified on at least one element vertically adjacent to a second layer of packing (11') in which the edges are unmodified on substantially all of the elements, whereby an unmodified edge on at least one of the elements in the second layer is adjacent one of the modified edges in the first layer.</p> |
