Evaluation of metallic filter media for sub-micrometer soot particle removal at elevated temperature

Abstract

Soot particle removal performance of two types of metallic filter media, sintered metal powder and sintered metal fiber, is experimentally evaluated as potential improvements to conventional ceramic filtration media for gasoline direct injection (GDI) engine PM after-treatment application. Soot collection efficiency and flow resistance of several grades of metallic media are measured at temperatures of 25, 350, and 650 C and a range of representative filtration velocities for submicrometer soot particles generated from a propane flame. Theoretical collection efficiency based on single fiber efficiency theory shows good agreement with experimental data for nearly spherical KCl particles at 350 C. Improved collection efficiency is observed for soot particles in the interception-dominated size range above »100 nm due to enhanced interception length. Soot collection is slightly enhanced at higher temperature, which is consistent with model predictions. Sintered metal fiber media are found capable of removing »75% of soot particles by mass with an incremental flow resistance of less than 1.5 kPa under 10 cm/s and 350 C, which is promising for gasoline particulate filter (GPF) application. The media level figure of merit (FOM) is used to quantify the soot collection efficiency versus flow resistance tradeoff of all media tested. It is found that due to their more open structure (higher porosity) sintered metal fiber media have FOMs nearly one order of magnitude higher than those of sintered metal powder media, and by analogy those of conventional wall flow ceramic media. This suggests that sintered metal fiber media represents an attractive alternative to ceramic media for designing GPFs; however, further research into creating comparable surface area to the honeycomb structures used for wall flow filters is needed to extract the full potential of metal fiber media.

Alternative Face Masks Made of Common Materials for General Public: Fractional Filtration Efficiency and Breathability Perspective

“…Air filtration is not as simple as sieving, and there are several filtering mechanisms, including inertial impaction, interception, diffusion, electrostatic deposition, etc. With different filtration mechanisms dominating particle size less than 0.1 µm or particle size in the range of 0.3-1 µm, overall fractional filtration efficiency curve will be a U-shape (Spurny, 1986;Yang, 2012;Ou et al, 2017). The particle filtration efficiency strongly depends on the particle size (Spurny, 1986;Ou et al, 2017).…”

“…With different filtration mechanisms dominating particle size less than 0.1 µm or particle size in the range of 0.3-1 µm, overall fractional filtration efficiency curve will be a U-shape (Spurny, 1986;Yang, 2012;Ou et al, 2017). The particle filtration efficiency strongly depends on the particle size (Spurny, 1986;Ou et al, 2017). The fraction filtration efficiency is defined as the number of particles of a given size penetrating the filter medium, divided by the total number of particles challenged on it.…”

An Experimental and Numerical Study on the Cleaning of Pleated Bag Filters Using Low-Pressure Pulsed-Jets

“…Many scholars [11][12][13][14] improved the dust cleaning effect by changing the structure of the pulsed-jet cleaning system, such as built-in rotation, injection distance, nozzle diameter, nozzle type, pulsed-jet cleaning type, pleated structure and so on. Some studies [15][16][17][18][19] indicated that changing the parameters of the pulsed-jet cleaning system, such as the cleaning algorithms, tank pressure, pulse width, filter media, maximum allowable pressure drop, and cleaning mode, can improve the dust cleaning performance. Chen et al [20][21][22] and other scholars studied the transient static pressure field of four-fold pleated filter cartridges during pulsed-jet cleaning.…”

An efficient and continuous filter operation for dust‐laden flue gas based on a self‐cleaning stainless steel weaved filter

“…30 Currently, stainless steel filters are formed by sintering stainless steel fibers and pressing to form a certain thickness of stainless steel fiber felt. 10 Ou et al 31 compared the filtration efficiency of sintered stainless steel filters and ceramic filters for high-temperature flue gas, and the former performs better than ceramic ones in both filtration efficiency and flow resistance. Li et al 15 showed that the porous sintered stainless steel fiber filters made at high temperatures and pressures met requirements of environmental emission standards and downstream heat recovery.…”