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Experiments and Analyses on Stability/Mid-Channel Collapse of Ash-Deposit Wall Layers and Pre-Mature Clogging of Diesel Particulate Filters
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 2, 2019 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
The conventional concept of soot and ash wall deposits (i.e. cake-layers) gradually building up along the channels of a ceramic honeycomb and then periodically or continuously being swept downstream toward the end-plugs of the channels may not always occur in practice. When deposits irregularly form on or detach from the walls, causing premature clogging usually around the mid-sections of the channels (also known as Mid-Channel Collapse), and the particulate filter is prone to experiencing significantly elevated back pressure, resulting in the need for earlier repair or replacement than desired. Here we describe related experiments that were performed, accompanied by analysis and simulation, in order to investigate the factors that contribute to the patterns of wall deposits that form-particularly of ash-and the effects of these irregular patterns.
Experiments attempting to duplicate conditions in which irregular deposits occur were carried out with a combination of actual engine and diesel-burner exhaust to achieve a variety of exhaust conditions, such as changing soot and ash concentrations and their relative ratios, flow rates (space velocities), and exhaust temperatures. In this study, the particulate filter was loaded with different soot ash ratios in the exhaust and periodically regenerated. X-Ray Computed Tomography (CT) was used to scan the spatial distributions of the ash deposits, radially and axially along the channels for the various conditions. In addition, HRSEM (High Resolution Scanning Electron Microscopy) and FIB (Focused Ion Beam) were employed to monitor the filter wall surface and deep-bed area respectively, and then related images were analyzed to study the detailed morphology of the ash deposits and their interactions with the substrate.
Computer simulations were also conducted, in conjunction with the image analyses, to correlate the results of the physical plugging and deposit distribution information, and to decipher the plausible connections to the soot/ash deposit conditions. The ultimate objective is to isolate the causes of Mid-Channel Collapse and control the stability and progression of the deposits.
Experiments have explored only a relatively small portion of the full test matrix we have generated that was intended to elucidate all potentially contributing factors. However, interesting data have already begun to emerge. Results thus far indicate that the observed patterns of irregular deposits are consistent with the corresponding measured pressure-drop data, and that the exhaust and soot/ash accumulation parameters affecting local temperatures (peak, duration, frequency) do appear to affect the properties of the cake layer and DPF performance as well.
CitationWang, Y., Obuchi, Y., Zhang, J., Tracy, I. et al., "Experiments and Analyses on Stability/Mid-Channel Collapse of Ash-Deposit Wall Layers and Pre-Mature Clogging of Diesel Particulate Filters," SAE Technical Paper 2019-01-0972, 2019, https://doi.org/10.4271/2019-01-0972.
Data Sets - Support Documents
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- Konstandopoulos, A.G. and Johnson, J.H., “Wall-Flow Diesel Particulate Filters-Their Pressure Drop and Collection Efficiency,” SAE Technical Paper 890405, 1989, doi:10.4271/890405.
- Konstandopoulos, A.G., Skaperdas, E., Warren, J., and Allansson, R., “Optimized Filter Design and Selection Criteria for Continuously Regenerating Diesel Particulate Traps,” SAE Technical Paper 1999-01-0468, 1999, doi:10.4271/1999-01-0468.
- Gaiser, G. and Mucha, P., “Prediction of Pressure Drop in Diesel Particulate Filters Considering Ash Deposit and Partial Regenerations,” SAE Technical Paper 2004-01-0158, 2004, doi:10.4271/2004-01-0158.
- Sappok, A. et al., “Characteristics and Effects of Ash Accumulation on Diesel Particulate Filter Performance: Rapidly Aged and Field Aged Results,” SAE Technical Paper 2009-01-1086, 2009, doi:10.4271/2009-01-1086.
- Sappok, A. and Wong, V.W., “Ash Effects on Diesel Particulate Filter Pressure Drop Sensitivity to Soot and Implications for Regeneration Frequency and DPF Control,” SAE Int. J. Fuels Lubr. 3(1):380-396, 2010, doi:10.4271/2010-01-0811.
- Wang, Y., Wong, V., Sappok, A., and Munnis, S., “The Sensitivity of DPF Performance to the Spatial Distribution of Ash Inside DPF Inlet Channels,” SAE Technical Paper 2013-01-1584, 2013, doi:10.4271/2013-01-1584.
- Dittler, A., “Ash Transport in Diesel Particle Filters,” SAE Technical Paper 2012-01-1732, 2012, doi:10.4271/2012-01-1732.
- Aravelli, K. and Heibel, A., “Improved Lifetime Pressure Drop Management for Robust Cordierite (RC) Filters with Asymmetric Cell Technology (ACT),” SAE Technical Paper 2007-01-0920, 2007, doi:10.4271/2007-01-0920.
- Ishizawa, T., Yamane, H., Satoh, H., Sekiguchi, K. et al., “Investigation into Ash Loading and Its Relationship to DPF Regeneration Method,” SAE Int. J. Commer. Veh. 2(2):164-175, 2009, doi:10.4271/2009-01-2882.
- Kim, K., Mital, R., Higuchi, T., Chan, S. et al., “An Investigative Study of Sudden Pressure Increase Phenomenon Across the DPF,” SAE Technical Paper 2014-01-1516, 2014, doi:10.4271/2014-01-1516.
- Fukui, R., Okamoto, Y., and Nakao, M., “Experimental Analysis of Sudden Pressure Increase Phenomenon by Real-Time Internal Observation of Diesel Particulate Filter,” Journal of Engineering for Gas Turbines and Power 138(10):102803-102807, 2016.
- Wang, Y. and Kamp, C., “The Effects of Mid-Channel Ash Plug on DPF Pressure Drop,” SAE Technical Paper 2016-01-0966, 2016, doi:10.4271/2016-01-0966.
- Ogyu, K., Ohno, K., Hong, S., and Komori, T., “Ash Storage Capacity Enhancement of Diesel Particulate Filter,” SAE Technical Paper 2004-01-0949, 2004, doi:10.4271/2004-01-0949.
- Nitschke, D. and Schmidt, E., “A New Approach to Model the Re-Entrainment of Settled Particles Based on Film Theory of Fluid Mass Transfer Processes,” Particle & Particle Systems Characterization 26(1-2):58-68, 2009.
- Nitschke, D. and Schmidt, E., “Untersuchung und Modellierung der Aufwirbelung von auf Oberflächen abgelagerten Partikelschichten,” Chemie Ingenieur Technik 82(12):2119-2127, 2010.
- Konstandopoulos, A.G., Kostoglou, M., Housiada, P., Vlachos, N. et al., “Multichannel Simulation of Soot Oxidation in Diesel Particulate Filters,” SAE Technical Paper 2003-01-0839, 2003, doi:10.4271/2003-01-0839.
- Kamp, C.J., Sappok, A., Wang, Y., Bryk, W. et al., “Direct Measurements of Soot/Ash Affinity in the Diesel Particulate Filter by Atomic Force Microscopy and Implications for Ash Accumulation and DPF Degradation,” SAE Int. J. Fuels Lubr. 7(1):307-316, 2014, doi:10.4271/2014-01-1486.
- Sappok, A., Govani, I., Kamp, C., Wang, Y. et al., “In-Situ Optical Analysis of Ash Formation and Transport in Diesel Particulate Filters During Active and Passive DPF Regeneration Processes,” SAE Int. J. Fuels Lubr. 6(2):336-349, 2013, doi:10.4271/2013-01-0519.
- Sappok, A., Wang, Y., Wang, R., Kamp, C. et al., “Theoretical and Experimental Analysis of Ash Accumulation and Mobility in Ceramic Exhaust Particulate Filters and Potential for Improved Ash Management,” SAE Int. J. Fuels Lubr. 7(2):511-524, 2014, doi:10.4271/2014-01-1517.
- Harris, T., Kozlov, A., Ayyappan, P., and Combs, J., “Engine Test Protocol for Accelerated Ash Loading of a Diesel Particulate Filter,” SAE Technical Paper 2011-01-0607, 2011, doi:10.4271/2011-01-0607.
- Sappok, A.G., Beauboeuf，, D., and Wong, V.W., “A Novel Accelerated Aging System to Study Lubricant Additive Effects on Diesel Aftertreatment System Degradation,” SAE Int. J. Fuels Lubr. 1(1):813-827, 2008, doi:10.4271/2008-01-1549.
- Sappok, A., Santiago, M., Vianna, T., and Wong, V., “Characteristics and Effects of Ash Accumulation on Diesel Particulate Filter Performance: Rapidly Aged and Field Aged Results,” SAE Technical Paper 2009-01-1086, 2009, doi:10.4271/2009-01-1086.
- Sappok, A. and Wong, V., “Ash Effects on Diesel Particulate Filter Pressure Drop Sensitivity to Soot and Implications for Regeneration Frequency and DPF Control,” SAE Int. J. Fuels Lubr. 3(2):380-396, 2010, doi:10.4271/2010-01-0811.
- Froelund, K. and Ross, M.G., “Laboratory Benchmarking of Seven Model Year 2003-2004 Heavy-Duty Diesel Engines Using a CI-4 Lubricant,” SAE Technical Paper 2005-01-3715, 2005, doi:10.4271/2005-01-3715.