Analysis of operational filtration data part III: re-entrainment and incomplete cleaning of dust cake

Operational data for the hot-gas filtration system of the Integrated Gasification and Cleanup Facility (IGCF) at the Federal Energy Technology Center are carefully analyzed. A model that includes re-entrainment of filter-cake fragments following cleaning of the candle filters, as well as incomplete removal of cake from the filters by the cleaning backpulses of compressed air, is developed and used to interpret the data. The parameters of the model are evaluated with a least-square error fit procedure. It is shown that inclusion of the re-entrainment model significantly improves the fit to the data during the short interval (;50 s after each backpulse) during which re-entrainment is predicted to occur by particle-transport modeling. The re-entrainment/incomplete-cleaning model is used to evaluate the buildup of filter-cake thickness and the filter-cake permeability. Both effects were significant for the data analyzed.