Fire barrier in building's air vents incorporates barrier plate, layer of intumescent material on one side, and covering

摘要

At least one barrier plate in two semicircular halves (3) is moved into a closed position for closing the ventilation-duct. At least one of the plate sides has at least one layer (8) of intumescent material which swells up at high temperatures. The side of the layer of intumescent material facing away from the barrier plate is lined with a covering plate. The barrier and covering plates are joined allowing relative lifting movement of the covering plate.