Computational study of fouling deposit due to surface-coated particles in coal-fired power utility boilers

Fouling deposits due to surface-coated particles have been calculated using computational fluid dynamics techniques. The sticking probabilities of the surface-coated particles are also evaluated on the basis of an energy balance. The sticking probabilities of the deposit surface are also included in the prediction of the deposition occurring through the multiple impaction of particles with the deposit surface. The sticking probability of an impacting particle is expressed in terms of such parameters as particle viscosity, surface tension, impact velocity, impact angle and the thickness of the sticky layer on a particle. Particulate behavior around a tube in cross-flow was studied using the Lagrangian approach. Three important parameters, i.e. impact velocity, impact angle, and particulate concentration, were used in the prediction of deposition rate. The computational predictions were found to be in good agreement with the experimental data.