Experience of Recovery Boiler Superheater Corrosion at Carter Holt Harvey Kinleith

摘要

The cause of severe localized corrosion of hockey sticks on the 2nd and 3nd stage superheater pendants in a recovery boiler was investigated. The results suggest that the problem was likely caused by high tube surface temperatures resulting from a combination of the lack of steam temperature control in the 2nd stage superheater, direct exposure to intense radiant heat from the lower furnace, uneven gas flow distribution across the boiler, and impaction of molten and burning carryover particles on the tube surface. Of these the lack of steam temperature control appears to be the most important. The problem has been eliminated through a major boiler upgrade.