External Corrosion of Superheaters in Boilers Firing High-Alkali Coals

In the past few years, corrosion of high-temperature superheaters and reheaters has become an increasingly serious problem on coal-fired boilers. A type of corrosion that has occurred on several boilers in the Chicago area which burn high-alkali coal is described. The results obtained from an experimental study of the factors influencing the rate of attack and the control measures applied are described.