Effect of dendritic structure on the filtration performance of fibrous media during dust loading by CFD-DEM.

Abstract

Fibrous media filtration is effective to control particulate matter contamination in the air. To achieve filter performance precisely, the particle deposition with a 3-D fiber model was established based on the bag filter (F8) fibrous media and performed the effects of solid volume fraction (SVF), dust concentration and particle size on the filtration efficiency during the dust loading process by CFD-DEM. The results showed that the efficiency increased as the SVF of fibrous media increased. As particle size increased from 1 μm to 120 μm, the filtration efficiency improved from 51% to 97%. Filtration efficiency was proportional to the dust concentration and fluctuated at more than 90%. Furthermore, the dendritic structure affected filtration performance. The equivalent solid volume fraction (ESVF) was proposed, due to analyzing the collapse and reconstruction of dendritic structures during particle deposition. When the fluid velocity increased from 0.04 m/s to 0.21 m/s, the efficiency fell by around 20% because the dendritic structure of particles on the fiber was disrupted resulting in a reduction of the ESVF. These findings could provide aids to optimize the filtration performance and improve the indoor environment quality.