Cut-off apparatus for ducts of large cross-sections, in particular for exhaust gas and smoke gas ducts of power stations

摘要

The invention relates to a duct housing having a sealing-air duct as a stop for a cut-off flap with a double seal around the peripheral edge for blowing in sealing air. The sealing-air duct is divided into sealing-air duct sections. The sealing-air duct sections form expansion joints between them and adjoin the duct housing in the longitudinal direction with a given freedom of movement. The expansion joints are bridged by internal tube sections which are inserted in the sealing-air duct sections with a sealing effect. The longitudinally movable sealing-air duct sections guarantee satisfactory compensation of the thermal expansions occurring as a result of temperature differences. <IMAGE>