Double-walled structure in a ventilation duct system
AssigneeLindab AB
InventorsKent Hultberg, Teuvo Ranta, Hans Larsson
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Abstract
A double-walled structure in a ventilation duct system has an inner tube and an outer tube and, arranged therebetween, a sound-absorbing material. The inner tube is a helically-wound lock-seam tube formed from a sheet metal strip having parallel longitudinal areas of expanded metal.
Claims15
A double-walled structure in a ventilation duct system, comprising:
- an inner tube;
- an outer casing spaced from and enclosing said inner tube;
- and
- a sound-absorbing material provided between said inner tube and said casing;
- wherein said inner tube is a helically-wound lock-seam tube formed from a sheet metal strip having at least one longitudinal area of expanded metal.
A double-walled silencer for use in a ventilation duct system, comprising:
- an inner tube;
- an outer tube spaced from and enclosing said inner tube;
- a tubular space defined by said inner tube and said outer tube;
- and
- a sound-absorbing material provided in and filling up said space between said inner tube and said outer tube;
- wherein said inner tube is a helically-wound lock-seam tube formed from a sheet metal strip having at least one longitudinal area of expanded metal.
A sheet metal strip having at least one longitudinal area of expanded metal, adapted for producing a helically-wound lock-seam tube as an inner tube in a double-walled structure in a ventilation duct system, and preferably acting as a silencer.
Dependencies are inferred from the claim text.