Study on the filtration behavior of a metal fiber filter as a function of filter pore size and fiber diameter

•We report empirical results of deposition characteristics of metal fiber filter.•The pore size decrease affected on the filtration efficiency increase.•Fiber diameter increase enhanced the faster particle deposition rate.

The filtration characteristics of a metal fiber filter on dry soot particles have been investigated empirically as a function of the filter pore size and fiber diameter. Six types of metal fiber filters, having various pore sizes and fiber diameters, were examined experimentally, with a focus on the pressure drop, deposited mass, and filtration efficiency. Filtration efficiency was calculated based on the particle number concentration and expressed as a function of the electrical mobility diameter and time. Dry soot particles were generated by a soot generator (mode diameter: 100 nm; total number concentration: 3.48×1010/cm3). The deposition temperature, total flow rate, and deposition time were set to 250 °C (equivalent to a particle approach velocity of 1.7 m/s), 29.2 sLPM, and 1 h, respectively.Our results showed that the pressure drop, mass, and particle number concentration-based filtration efficiency exhibited the same tendencies. Specifically, the filter pore size influenced the initial and final filtration efficiencies, while the fiber diameter had a significant effect on the rate of increase of the filtration efficiency.