Numerical simulation of dual-layer granular bed filtration under external electric field.

In order to reveal the electrostatic enhancement filtration effect of a dual-layer granular bed filter with an external electric field, a coupled numerical model was established, including the flow field, discrete particle field, electric field and particle collision rebound effect, then the electrostatic enhancement filtration effect of each filter layer was calculated and investigated under different filtration velocities, different temperatures and different electric field intensities, respectively. The results show that the grade filtration efficiencies of the upper and lower filter layers decrease with the increase of filtration velocity, the electrostatic enhancement filtration effect of the external electric field on the fine particles is more obvious, the electrostatic enhancement filtration effect of the upper filter layer is greater at low velocity, and the electrostatic enhancement filtration effect of the lower filter layer is greater at high velocity. The grade filtration efficiencies of the upper and lower filter layers decrease with the increase in temperature, and the electrostatic enhancement filtration effect is more obvious at low temperatures. The grade filtration efficiencies of the upper and lower filter layers increase with the increase of electric field intensity. [Display omitted] • Simulation of electrostatically enhanced granular bed filter. • Local electric fields enhance at the gap and contact of the granules. • Filtration efficiency decreases with velocity increase due to particle rebound. • The electrostatic enhancement filtration effect is larger for fine particles. [ABSTRACT FROM AUTHOR]