Experimental Investigation on Characterization of Simulation Soot Deposited on Diesel Particulate Filter

Based on a visualized single channel filtration testing bench, on which a solid particle generator is used to generate particles on the diesel particulate filters'(DPF)surface, the deposition characterization of particle layer in diesel particle filter was investigated online by laser displacement measurement and offline by microscopic technology. Then, the effect of surface filtration velocity, carbon blacks' specification and ash loading was investigated in the experiment. Results show that the soot deposition process could be divided into four stages based on the particle layer thickness curve:the deep bed filtration stage, the particle tree growth stage, the particle tree connection stage and the particle layer filtration stage. It also could be divided into deep bed filtration stage, transition stage and particle layer filtration stage based on the pressure drop curve. The particle deposition process begins at the particle layer filtration stage when the layer thickness reaches about 15-30 μm under the different surface filtration velocities tested. Increasing the surface filtration velocity leads to the increase of pressure drop and layer thickness with denser soot layer. The aggregation degrees of different commercial carbon black particles(SB4A>FW200>PU)plays an important role in filtration pressure drop and bulk density. With the increase in the amount of ash deposited on the surface( 0-6 g/L), the initial pressure drop increases, but the filtration pressure drop and soot cake bulk density decrease at first and then increase gradually. When the ash deposition is 2 g/L, the final pressure drop and soot cake bulk density reach their minimum values. © 2019, Editorial Office of the Transaction of CSICE. All right reserved.