INNER FACE PROTECTING STRUCTURE IN EXHAUST GAS DUCT

PROBLEM TO BE SOLVED: To provide an inner face protecting structure in an exhaust gas duct capable of keeping a constant slit width to thermal expansion and preventing attachment of dust and corrosion of the duct. SOLUTION: This inner face protecting structure is composed of duct main bodies 1, 1' through which an exhaust gas passes, circular air swirling chambers 2 mounted on outer faces of lower end portions of the duct main bodies, and a plurality of air supply pipes 3 connected with outer peripheral faces of the chambers 2 at prescribed intervals in the circumferential direction, in duct units 4, 4'. Circular slit portions 5 are respectively formed between the duct main body and the chamber to supply the cooling air along an inner face of the duct. Preferably, the plurality of duct units are stacked. A plurality of slit guide plates 9 are mounted in the slit portions at prescribed intervals in the circumferential direction in a state of being inclined in the longitudinal direction of the duct. COPYRIGHT: (C)2006,JPO&NCIPI