Experimental study on the pressure drop and thickness variation of carbon black particle layer during oxidation on DPF channels

Abstract

Investigating the evolution of pressure drop and particle layer thickness during oxidation is crucial for comprehending the regeneration performance of diesel particulate filters (DPFs) and optimizing the regeneration process. In this study, a visualized single-channel test bench was employed to actively regenerate carbon black particle layers on DPF channels. Online measurements and dynamic analysis of pressure drop and particle layer thickness were conducted to examine their behaviors. The results demonstrated that the particle layer regeneration process can be categorized into three stages. In the first stage, the pressure drop gradually decreased while the thickness continued to increase. In the second stage, the pressure drop reduction rate significantly accelerated with increasing deposition thickness (particularly between 112 μm and 147 μm), while the particle layer continued to thicken due to thermal expansion, reaching a peak of 193 μm before declining. For layers thicker than 273 μm, continuous thickening was observed. In the third stage, the pressure drop reached its minimum value, and the rate of thickness decrease became relatively high. Notably, a time delay was observed between the rapid decline in thickness and the steep decrease in pressure drop, which increased with the thickness of the particle layer. At a deposition thickness of 404 μm, the particle layer became suspended on the filter wall during the heating process, creating a gap .