Gas flow and particle deposition in the hot gas filter vessel at the Tidd 70 MWE PFBC demonstration power plant

Advanced hot-gas filtration systems for clean coal technologies have attracted considerable attention in recent years. The Tidd hot-gas filtration system was the first demonstration unit in the United States. The system was operational for about four years (1990–1994) and has provided considerable engineering information concerning the operation of the demonstration-scale hot-gas particle filtration system. The present work describes a computer simulation study of gas flow and particle transport and deposition in the Tidd filter vessel. The FLUENT™ code is used for evaluating the gas mean velocity, mean pressure, and the state of turbulence in the filter vessel. The three tiers with a total of 384 filters are modeled as three effective cylindrical filters. The particle equation of motion that includes the nonlinear drag and the gravity is used. The particle deposition patterns are evaluated, and the effect of particle size is studied. The results show that, for a clean filter system, the rate of deposition on different tiers depends on particle size. This could lead to nonuniform composition and thickness of the cakes that form on the candle filters in different tiers.