Particle deposition and detachment in capillary sphere packings

Flow simulations in a random sphere packing are used to investigate particulate filtration processes. The local wall shear stress is used to calculate an angular dependent distribution for particle detachment. Simulations of particle deposition by interceptions yield the angular dependent number of impacts. The results from particle detachment calculations and the interception analysis are combined to estimate local particle deposition rates, employing probabilities for detachment and impact. Comparison with X-ray computer tomography of deposited particles within a sphere packing shows good agreement. Therefore, the presented simulation procedure can be used for the design of, e.g., particle filtration apparatus.

► Particle deposition on a single sphere collector is simulated.
► Trajectory analysis delivers particle impact rate and positions.
► Particle detachment due to wall shear stress and a sliding or rolling mechanism.
► Single collector efficiencies are estimated.
► Particle deposition curve is confirmed by X-ray tomography.