Particle Transport and Deposition in a Hot-Gas Cleanup Pilot Plant

ABSTRACT

Development of hot-gas filtration systems for advanced clean coal technologies has attracted considerable attention in recent years. The Integrated Gasification and Cleanup Facility (IGCF), which is an experimental pilot plant for testing performance of ceramic candle filters for hot-gas cleaning, has been operational at the Federal Energy Technology Center (FETC) in Morgantown, West Virginia, for several years. The present work describes a computer simulation study of gas flow and particle transport and deposition in the IGCF filter vessel with four filters. The stress transport model of FLUENT? code is used for evaluating the gas mean velocity and the root mean-square fluctuation velocity fields in the IGCF filter vessel. The instantaneous fluctuation velocity vector field is simulated by a filtered Gaussian white-noise model. Ensembles of particle trajectories are evaluated using the recently developed PARTICLE code. The model equations of the code include the effects of lift and Brownian motion in addition to gravity. The particle deposition patterns on the ceramic filters are evaluated, and the effect of particle size is studied. The results show that, for a clean filter (just after the backpulse), the initial deposition rate of particles on the candle filters is highly nonuniform. Furthermore, particles of different sizes have somewhat different deposition patterns, which could lead to nonuniform cake compositions and thicknesses along the candle filters. The effects of variations in the filter permeability on the vessel gas flow patterns and the pressure drop, as well as on particle transport patterns, are also studied.