| 摘要 |
<p>The silencer has a casing with cylindrical sections (111,112,113,114) which increase in diameter from the inlet to the outlet (14). Each section contains a cylindrical insert (12,12',12") of porous sound absorbing material. Each insert has a larger dia. than the preceeding one. It is enclosed in a metallic sleeve with projecting ribs (116,116') which hold it off the internal lip of the casing immediately upstream of it. Its diameter is slightly less than that of the casing section it fits in. The resulting gaps (117,116,117',116',117") between and round the porous inserts allow flow to be maintained without a rise in pressure as the porous material becomes choked.</p> |
