Filtration for nano/micron-sized particulates with a moving bed filter

Particulate Matter (PM) pollution has attracted much attention as it represents a serious threat to public health. Granular bed filtration is a highly efficient gas cleaning technique at high temperatures. A counter-current moving bed granular filter with novel internal components was proposed to capture fine particulates. The effects of the moving bed filter on removing the fine dust particulates with various sizes (micron and nanometer scale) were investigated. The experimental results indicate that dust is easily captured under a low superficial gas velocity or a high capturing particle moving velocity. In a moving bed filter with the counter-current flow, diffusion is the dominant collection mechanism for the nanometer dust; on the other hand, the micron dust capturing is a combined effect with multiple mechanisms including diffusion, sedimentation, interception, and impaction. An efficiency calculation model was constructed based on the experimental results and the singleparticle filtration mechanism.