| 摘要 |
<p>A double-walled-structure, such as a silencer for use in a ventilation duct system, comprises a perforated inner tube (10), an outer casing (30) which is arranged at a distance from the inner tube (10) and encloses the same, and a tubular, sound-absorbing element (20) which is arranged between the inner tube (10) and the casing (30). The tubular element (20) has an increasing density radially outwards from the centre axis (C) of the inner tube (10). The silencer (1) is produced by the sound-absorbing element (20) being arranged on the inner tube (10), and the inner tube (10) with the sound-absorbing element arranged thereon being enclosed in the surrounding outer casing (30). <IMAGE></p> |
