Particle combination characteristics on PM2.5 granular bed filtration efficiency and pressure drop

Granular bed filters are widely utilized in hot gas dust removal due to their low cost, high temperature resistance, and simple structure compared with other dust removal methods. Conventional granular bed filtration is usually only applicable to the separation of particulate matters above PM10, and its PM2.5 efficiency separation needs to be improved. A new method for efficiently separating PM2.5 is developed in this study by combining different filter media. The effects of filter deck thickness, filter mediums diameter, and granular bed combination characteristics on PM2.5 separation efficiency and separation pressure drop are systematically studied. A group of single-deck filtration experiments show that the average separation efficiency for PM2.5 can reach 92.9% with an average separation pressure drop of 0.53 kPa. Double-deck granular bed filtration can also offer an average separation efficiency for PM2.5 91.2%, but the average separation pressure drop is significantly reduced to 0.4 kPa. The results prove that compared with a single granular bed; double granular beds demonstrate evident advantages in energy consumption ratio. This study provides references for studying PM2.5 in depth separation and granular bed filtration.