Filtration characteristics of a binary multi-layer granular bed flter based on CFD-DEM coupling simulation

The coupled CFD-DEM method with the JKR(Johnson-Kendall-Roberts)model for describing the contact adhesion of dust to filter particles(FPs)is used to simulate the distribution pattern of dust particle deposition in the granular bed filter(GBF)with multi-layer media.The minimum inlet flow velocity must meet the requirement that the contact probability between dust and FPs is in the high contact probability region.The air flow forms vortices on the leeward side of the FPs and changes abruptly at the intersection of different particle size FPs layers.Dust particles form large deposits at the intersection of the first and second layers and the different particle size filter layers.Dual element multilayer GBF can further optimize the bed structure by interlacing filter layers with different particle sizes.Compared with single particle size multi-layer GBF,the bed pressure drop is reduced by 40.24%-50.65%and the dust removal efficiency is increased by 21.93%-55.09%.