| 摘要 |
<p>A gassing apparatus (10) including a composite gas flow screen having a plurality of respective screen elements (29, 31 and 33), at least one respective flow opening (37, 39, 41) therein, the cross-sectional areas of the respective flow openings in these respective elements decreasing in a downstream direction with respect to gas flow and at least one other screen element (3) having no flow opening. A nozzle (27) preferably produces a relatively high velocity central gas stream (57) with surrounding gas streams (49, 51, 53, 55) of decreasing velocity as they are spaced further away from the central gas stream (57). Methods and apparatus are described.</p> |
