COATINGS AND SURFACE TREATMENTS FOR PROTECTION AGAINST LOW-VELOCITY EROSION-CORROSION IN FLUIDIZED-BEDS

Surface coatings and treatments have been used to reduce material loss of components in bubbling fluidized bed combustors (FBCs). The perfor mance of protective coatings in FBC boilers and laboratory simulations is reviewed. Important coating properties to minimize wastage appear to be high hardness, low oxidation rate, low porosity, high adhesion a nd sufficient thickness to maintain protection for a long period. Econ omic considerations and criteria for choosing a suitable coating or tr eatment are discussed for the different types of bubbling FBC.