Absorptive sound attenuator, in particular for air ducts in paper mills
First Claim
1. An absorptive sound attenuator for use in connection with air ducts, in particular for intake and/or exhaust air ducts of paper mills, comprising:
- an enclosure having an outer wall and an aperture formed thereto;
a conduit forming an air duct for transmitting an air flow, having a perforated wall, located inside said enclosure, said perforated wall allowing acoustic vibrations from the conduit to be transmitted therethrough;
removable sound absorbing material for absorbing acoustic vibrations in the area around said conduit which are transmitted through the perforated wall, located inside said enclosure and around said conduit;
means for opening and closing said aperture for selectively inserting and removing said sound absorbing material, through said aperture, from outside of said conduit;
said enclosure having a longitudinal axis, a rectangular cross section in a plane perpendicular to the longitudinal axis, defining four outer walls, said means for opening and closing comprising at least two openable planar outer walls of said enclosure disposed parallel to said longitudinal axis, so that air flows generally parallel to said longitudinal axis of the enclosure;
said conduit having a circular cross section shape in a plane perpendicular to the longitudinal axis, so that air flows generally parallel to said longitudinal axis of the enclosure; and
said sound absorbing material in said enclosure comprising at least four pieces of absorption material, which have a cylindrical inner face and planar outer faces, said cylindrical inner face facing said perforated duct and each of said planar faces facing one of said walls of said enclosure.
1 Assignment
0 Petitions
Accused Products
Abstract
An absorptive sound attenuator, which is intended particularly for intake and/or exhaust air ducts in paper mills. The sound attenuator comprises a box-like duct housing (10), in whose interior there is an inner tube (19), which is provided with through perforations (19a) and which forms the air duct (20). Around the inner tube is placed sound absorbing material (21, 22). The inner tube (19) defines the air duct (20) in its interior, the sound being absorbed in the area of the air duct (20). In order to facilitate cleaning and/or replacing of the sound attenuator components and the absorption material (21,22,26) in the duct housing (10) the absorptive sound attenuator is provided with openable outer walls (13a,13b,14a,14b,13A,13B). When these walls are open, the absorption material (21,22,26) can be removed and/or replaced from outside the inner tube (19).
18 Citations
16 Claims
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1. An absorptive sound attenuator for use in connection with air ducts, in particular for intake and/or exhaust air ducts of paper mills, comprising:
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an enclosure having an outer wall and an aperture formed thereto; a conduit forming an air duct for transmitting an air flow, having a perforated wall, located inside said enclosure, said perforated wall allowing acoustic vibrations from the conduit to be transmitted therethrough; removable sound absorbing material for absorbing acoustic vibrations in the area around said conduit which are transmitted through the perforated wall, located inside said enclosure and around said conduit; means for opening and closing said aperture for selectively inserting and removing said sound absorbing material, through said aperture, from outside of said conduit; said enclosure having a longitudinal axis, a rectangular cross section in a plane perpendicular to the longitudinal axis, defining four outer walls, said means for opening and closing comprising at least two openable planar outer walls of said enclosure disposed parallel to said longitudinal axis, so that air flows generally parallel to said longitudinal axis of the enclosure; said conduit having a circular cross section shape in a plane perpendicular to the longitudinal axis, so that air flows generally parallel to said longitudinal axis of the enclosure; and said sound absorbing material in said enclosure comprising at least four pieces of absorption material, which have a cylindrical inner face and planar outer faces, said cylindrical inner face facing said perforated duct and each of said planar faces facing one of said walls of said enclosure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 11, 12, 14, 15, 16)
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9. A sound attenuator for use in connection with air ducts, in particular for intake and/or exhaust air ducts of paper mills, comprising an enclosure having an outer wall and an aperture formed thereto;
- a conduit forming an air duct for transmitting an air flow, having a perforated wall, located inside said enclosure, said perforated wall allowing acoustic vibrations from the conduit to be transmitted therethrough;
removable sound absorbing material for absorbing acoustic vibrations in the area around said conduit which are transmitted through the perforated wall, located inside said enclosure and around said conduit; and
means for opening and closing said aperture for selectively inserting and removing said sound absorbing material, through said aperture, from outside of said conduit, wherein said enclosure further comprises a longitudinal axis, said conduit is disposed in a plane parallel to the longitudinal axis, so that air flows generally parallel to said longitudinal axis of the enclosure, further comprising guides and at least one plate of absorption material disposed inside said conduit, said plate comprising layers of absorption material sandwiched between two perforated plate walls, said walls lying in a plane generally parallel to said longitudinal axis and wherein said absorption plate is generally planar and slidably arranged in the guides, so that said absorption plate can be removed for cleaning or replacement and inserted through said aperture of said enclosure. - View Dependent Claims (10)
- a conduit forming an air duct for transmitting an air flow, having a perforated wall, located inside said enclosure, said perforated wall allowing acoustic vibrations from the conduit to be transmitted therethrough;
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13. A sound attenuator for use in connection with air ducts, in particular for intake and/or exhaust air ducts of paper mills, comprising an enclosure having an outer wall and an aperture formed thereto;
- a conduit forming an air duct for transmitting an air flow, having a perforated wall, located inside said enclosure, said perforated wall allowing acoustic vibrations from the conduit to be transmitted therethrough;
removable sound absorbing material for absorbing acoustic vibrations in the area around said conduit which are transmitted through the perforated wall, located inside said enclosure and around said conduit; and
means for opening and closing said aperture for selectively inserting and removing said sound absorbing material, through said aperture, from outside of said conduit, wherein said enclosure further comprises a longitudinal axis, said conduit is disposed in a plane parallel to the longitudinal axis, so that air flows generally parallel to said longitudinal axis of the enclosure, further comprising at least one membrane plate which is capable of oscillating in response to ambient acoustical vibrations, disposed inside said conduit and lying in a plane generally parallel to said longitudinal axis, so that the acoustical vibrations are decreased in amplitude, and wherein said membrane plate is generally planar and slidably arranged in guides, so that said membrane plate can be removed for cleaning or replacement and inserted through said aperture of said enclosure.
- a conduit forming an air duct for transmitting an air flow, having a perforated wall, located inside said enclosure, said perforated wall allowing acoustic vibrations from the conduit to be transmitted therethrough;
Specification