Method and composition for the prevention of high temperature corrosion due to alkali sulfates and alkali chlorides and composition for use in the same

摘要

An additive to a flame reaction that forms noncorrosive deposits on cooler metal surfaces that are more stable than Na2SO4 or K2SO4 is disclosed. The additive preferentially combines with the sodium or potassium, and sulfates of these will not be formed. By adding tungsten, tungsten salts or tungsten percursors to the flame, a complex sodium tungstate is produced on the surface of the cooler metal object in a dense form and corrosion is inhibited. The level of tungsten preferably present at an atomic concentration is equal to 1.5 to 2 times that of the sodium in the specific flame environment and possibly a little higher for potassium. The nature of the fuel and possible alkali reduction schemes will control the quantity and mixing method of the additive. The additive may be directly mixed into the fuel or injected into the burned gas regions of the combustion, Ta and Nb also appear as possible substitutes for W.