Investigations on fouling rate in convective bundles of coal-fired boilers in relation to optimization of sootblower operation

The article deals with results of full-scale investigations on fouling in convective bundles of chosen types of coal-fired boilers. The boilers tested were: conventional pulverized-coal fired two-pass boilers (two types), a single-pass subcritical (a tower shape) boiler and CFB boiler. Mechanisms of deposit formation and basics of deposit modeling are shortly discussed. An own approach to predict build-up of loose powdery sediments was developed on the basis of the results of full-scale measurements. The correlation for maximum fouling time was obtained by statistical processing of measurement data and is applied in optimization of sootblower system operation. The obtained correlation depends on the following variables: geometric properties of the bundle, fly ash size distribution and basic parameters of the flue gases - all of them are easily accessible in boiler operation.