Analysis on filtration characteristic of wall-flow filter for ash deposition in cake. (May 2016)

• Record Type: Journal Article
• Authors: Jiang, Junhao; Gong, Jinke; Liu, Weiqiang; Chen, Tao; Zhong, Chao
• Is Part Of: Journal of aerosol science. Volume 95(2016:May)
• Page Start: 73
• Page End: 83
• Publication Date: 2016-05
• Subjects: Wall-flow -- Diesel particulate filter -- Ash -- Cake deposition -- Filtration; Aerosols -- Periodicals; Aerosols -- Periodicals; Aérosols -- Périodiques; 541.34515
• DOI: 10.1016/j.jaerosci.2016.01.009
• Languages: English
• ISSNs: 0021-8502

Abstract

Abstract: Based on the characteristics of ash cake deposition, the single channel model and the packed bed model, a mathematical model of filtration process of wall-flow filter for ash deposition in cake has been proposed. The effects of the amount of ash load and the distribution of ash deposition in cake on the filtration characteristic of filter are analyzed. Results show that the filtration efficiency improves rapidly with the increase of ash load while ash layer proportion is nonzero. When ash layer proportion is zero (i.e. ash plug proportion is 100%), the filtration efficiency decreases with the increase of ash load. Otherwise, the filtration efficiency improves with the increase of ash layer proportion while the ash load is constant. Considering the effects of ash on both filtration efficiency and flow resistance, the active regeneration system is more helpful to balance the correlation between filtration efficiency and flow resistance for ash tends to build up at the end of the channels in active system. The experimental results have verified the accuracy of mathematical model. Graphical abstract: Fig. 8. Effects of ash layer proportion on filtration efficiency. Ash layer results in an additional filtration medium on the porous wall and a reduction of the flow cross section within the inlet channels, and the effective filtration length and ash layer thickness increase with the increase of ash layer proportion while ash load is constant, so the filtration efficiency of filter with high ash layer proportion is higher than the clean-filter along the whole range of particle diameter. Highlights: A mathematical model of filtration process of filter has been proposed. Increasing ash layer proportion will increase filtration efficiency. The active regeneration system can ease the effects of ash load on filter.