Abstract
It is very important to understand the mechanisms of the slagging and the fouling on the pulverized coal combustion in order to avoid the troubles due to ash depositions on furnace walls and tube surfaces. This review shows the fundamentals of ash deposition mechanisms and indices for predicting slagging and fouling propensities based on bulk compositions of coal. The new evaluation methods are also summarized, which use advanced coal analyses. A lot of indices based on bulk compositions of coal are widely used for prediction of ash depositions. These are, however, not applicable to determine the positions, where ash depositions occur, and the effect of combustion conditions. The advanced method by use of the numerical simulation techniques, which incorporate the models of ash formation process and ash deposition behavior during pulverized coal combustion, is desirable for precise evaluation.
