Guillotine dampers with blade sealing means accommodative of thermal expansion forces

A guillotine damper to be incorporated in the exhaust system of a gas turbine, said damper including framework provided with a supporting frame having upper, side and bottom portions and an inner frame having side and bottom portions which are U-shaped in cross section, a pair of laterally spaced, internally insulated transverse members connected to the framework and dividing the framework into an upper bonnet and a lower rectangular gas flow passageway with the space between the members constituting the bonnet entrance, thermal insulation between the frames, a guide in a plane inclusive of the space between the members and having side and bottom sections seated against the corresponding sections of the inner frame, means connecting the guide sections to the supporting frame through the corresponding inner frame sections and the insulation therein in a manner preventing thermal expansion forces from distorting the guide, and a rectangular blade dimensioned to close the passageway and to pass through the bonnet entrance for storage in the bonnet when the passageway is to be open, means connected to the blade and mounted on the bonnet and operable to lift the blade into the bonnet and to lower the blade from the bonnet into a position closing the passageway, said blade including a marginal frame consisting of upper, side and bottom sections provided with channels, the channels of the side sections in sliding contact with the side sections of the guide, the channel of the bottom section fitting over the bottom section of the guide as the blade reaches its closed position, and the channel of the upper section dimensioned then to be within the bonnet entrance, the sections of the marginal blade frame connected to the blade in a manner preventing the distortion of the channels thereof by thermal expansion forces.