Experimental study of dust deposition in dynamic granular filters

Abstract

The aim of the present study is to investigate the process of dust deposition and its effects on the filtration performance of dynamic granular filters. We proposed a new theoretical explanation about the model for dust cake formation and growth, especially for the compression model at higher filtration superficial velocities in dynamic granular filters. The thickness and porosity of dust cakes can be estimated by formulas. Then, the effects of cake formation and growth on filtration performance were examined. It is found that there is an optimum thickness of the cake at which the dynamic granular filter achieves excellent collection efficiency with low system resistance. Moreover, an increasing pattern of pressure drop with cake thickness under different filtration superficial velocities was observed. Experimental results show that the pressure drops across the filter system and dust cake increase exponentially with increasing filtration superficial velocity. An appropriate filtration superficial velocity should be considered to achieve optimum filtration performance in dynamic granular filters. It is expected that the results of this study could provide useful information on designing dynamic granular filters for removal of dust particulates in Integrated Gasification Combined-Cycle (IGCC) and Pressurized Fluidized-Bed Combustion (PFBC).