MELTAL SHEET VENTILATION/SMOKE DUCT SECTION AND MANUFACTURING METHOD THEREOF

摘要

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 characterised 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).