| 摘要 |
<p>A pipe unit 1 having a channelled section 4, such as a bellows de-coupler, presenting to the interior of the pipe unit axially spaced channels 12 that are open 5 to the interior of the pipe unit. Located at the upstream entrance of the channelled section and projecting inwardly from the inner wall of the pipe unit is a flow modifying element 20 formed around its peripheral extent adjacent to the inner wall with a plurality of peripherally spaced flow modifying edge formations 21 22, which serve to reduce noise level otherwise created by the presence of the channelled section. Preferably the walls of gas flow channels are defined by the modifying edge formations and the inner wall of the pipe unit, where the flow modifying element may be annular and the modifying edge formations may be provided as recesses at the outer peripheral edge of the annulus.</p> |
