Sealing members for use in gas preheater

A sealing member for sealing a gap between an outer peripheral portion of a rotor and a housing in a gas preheater or a gap between a side face of a rotor and a radial sealing member in the gas preheater, said gas preheater being adapted to recover heat from exhaust gases emitted from a boiler using coal or heavy oil as a fuel, wherein said sealing member comprises a base body having substantially a U-shaped cross section and a surface member fixed to upper opposite edge portions of said base body such that said surface member projects above upper end faces of said base body and at least a portion of said surface member contacts said rotor, said surface member comprising at least one material selected from the group consisting of:

• a) a ceramic selected from the group consisting of alumina-containing porcelain, alumina, silicon carbide, silicon nitride, mullite, sialon and zirconia, said ceramic having a coefficient of thermal expansion of not more than 70.times.10.sup.-7 /.degree.C.;
• and
• b) an inorganic glass selected from the group consisting of a glass lining consisting essentially of at least 55 wt% silicic acid, 0-10 wt% boric acid and 10-20 wt% alkali, and an acid-resistant enamel consisting essentially of at least 40 wt% silicic acid, 0-10 wt% boric acid and 10-30 wt% alkali;
• wherein said ceramic and said inorganic glass are water insoluble and acid resistant.