The impact of coal characteristics on the fouling of stoker-fired boiler convection surfaces

This paper presents a comparison of the degree of fouling in a hot water stoker-fired boiler after it has been fired with two types of coal with different characteristics for an extended period of time. The extent at which indices that characterise the tendency to cause slagging and fouling on boiler heating surfaces found in the literature correspond to the actual state of ash deposits in the boiler is discussed. New ranges of fouling indices values are proposed that correspond to the results from observing fouling in the boiler.