Metal sheet ventilation/smoke duct section and manufacturing method thereof
The invention relates to a metal sheet ( 15 ) ventilation/smoke exhaust duct section ( 10 ) for incorporation into a metal sheet ventilation/smoke exhaust duct, said metal sheets ( 15 ) being covered on the outside by a heat insulating material ( 20 ) and said duct section ( 10 ) including elongated stiffening bar members ( 30 ) located on the outside of the duct and attached to said metal sheets ( 15 ), the invention being characterized in said bar members ( 30 ) being located at a distance from said metal sheets ( 15 ), said bar members ( 30 ) being attached to said metal sheets ( 15 ) at discrete locations along the length of the bar members ( 30 ).
1. A metal sheet ventilation/smoke exhaust duct section that is a part of a metal sheet ventilation/smoke exhaust duct, said duct section comprising metal sheets covered on an outside thereof by a heat insulating material having an outer surface, elongated stiffening bar members arranged against the outer surface of the heat insulating material, said elongated stiffening bar members extending substantially transversely to an axial direction of said duct section and being attached by separate connecting means extending through said insulating material to said metal sheets at discrete locations along a length of the bar members.
2. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said bar members are metal bar members.
3. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein, said duct section includes at least two of said bar members spaced apart along the axial direction of said duct section.
4. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said bar members are rigidly connected at the ends thereof to form a frame extending peripherally around said duct section.
5. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , said bar members are received in an elongated groove formed in said insulating material.
6. The metal sheet ventilation/smoke exhaust duct section according to claim 3 , wherein said bar members are supported by said insulating material.
7. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said insulating material has a thickness of 35 mm-200 mm.
8. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said insulating material is a mineral wool product having a density of 50 kg/m 3 -350 kg/m 3 .
9. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said connecting means comprises metal screws engaging said bar members at discrete locations along the length of said bar members.
10. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said discrete locations are spaced apart by 200 mm-700 mm.
11. The metal sheet ventilation/smoke exhaust duct section according to the claim 10 , wherein said discrete locations are spaced apart by 250 mm-500 mm.
12. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said bar members have a U-shaped cross-section with a bottom of said U being located farthest from the duct section.
13. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said bar members having a T-shaped cross-section with the head of said T being located farthest from said duct section.
14. The metal sheet ventilation/smoke exhaust duct section according to claim 1 , wherein said insulating material extends between said metal sheet and said stiffening bar members.
15. A method for making a metal sheet ventilation/smoke exhaust duct section that is a part of a metal sheet ventilation/smoke exhaust duct, said duct section having metal sheets covered on an outside thereof by a heat insulating material having an outer surface, elongated stiffening bar members arranged against the outer surface of the insulating material, said bar members extending essentially transversally to an axial extension of said duct section, said method comprising applying connecting means extending through said insulating material to attach said bar members to said metal sheets at discrete locations along a length of said bar members.
16. The method according to claim 15 , including locating at least two of said bar members spaced apart along an axial direction of said duct section.
17. The method according to claim 15 , wherein said bar members are rigidly connected at the ends thereof to form a frame extending peripherally around said metal sheets.
18. The method according to claim 15 , comprising forming elongated grooves in said insulating material and locating one of said bar members within a corresponding one of said grooves.
19. The method according to claim 15 , wherein said connecting means are metal screws engaging said bar members and said metal sheets.
20. The method according to, said metal screws are applied at a mutual spacing of 200 mm-700 mm.
21. The method according to claim 15 , said bar members have a U-shaped cross-section with a bottom of said U being located farthest from said metal sheets.
22. The method according to claim 15 , wherein said bar members have a T-shaped cross-section with the head of the T being located farthest from said metal sheets.