Materials for DPF and its Cleaning Methodologies
To be published on November 21, 2019 by SAE International in United States
Event: NuGen Summit
Accumulation of ash in the Diesel Particulate Filter (DPF) with engine operating over the time is a major concern for all vehicle manufacturers, with BS VI and BS VII emission norms mandating the use of DPF. Ash deposition leads to increase in pressure drop across the filter and more frequent regeneration pattern, which can lead to sintering. It can hamper the capacity of soot loading, properties of DPF substrate material and can lower catalyst activity in case of Catalysed-DPF. Hence, removal of ash is important by defining the DPF cleaning methods. Primary source of ash is lubricant oil, taking part in the combustion. Lubricant additives like detergents and anti-wear agents are responsible for formation of metallic ash inside the DPF. Secondary source of metallic ash is fuel and engine wear out. The present paper elucidates the preparation of DPF samples including coating and canning of DPF substrates, with proper GBD. Pressure drop and weight with and without coating is estimated and validated through actual measurement of fresh as well as soot loaded samples. Soot loading is done by accelerated artificial ash loading protocol, with engine running on lubricant doped diesel fuel on an engine dynamometer. Experiments are conducted by cleaning the ash loaded DPFs with different cleaning techniques like Pneumatic cleaning, Solvent based cleaning, Bake or thermal cleaning. These cleaning techniques are compared in terms of cleaning efficiency, based on which the best cleaning technology are recommended for Indian conditions, in order to restore the DPF’s working condition without appreciable increase in pressure drop.