Modelling ash deposition in pulverized coal-fired applications

A predictive scheme based on CCSEM flyash data and computational fluid dynamics (CFD) was developed to study the slagging propensity of coals. The model was applied to predict the deposition potential of three UK coals; Bentinck, Daw Mill and Silverdale, in a pilot scale single burner ash deposition test facility. The project is part of a collaborative research programme sponsored by the UK Department of Trade and Industry and involved various industrial organizations and universities. The objective is to understand the fundamental aspects of slagging in pulverized coal-fired combustion systems. The present model predicts the relative slagging propensity of the three coals successfully, and the predicted deposition patterns are also consistent with the observations. The results from the model indicate a preferential deposition of iron during the initial stage of ash deposition. The average compositions of the deposits become closer to that of the bulk ash when the accumulation of ash deposits is taken into account. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.