Characteristics of Particulate Matter Collection in a Diesel Engine Using a Fluidized-bed DPF

Abstract

A fluidized bed filter was applied to filtrate particulate matter (PM) in diesel engine exhaust gas. Experiment was carried out using a single-cylinder DI diesel engine to investigate the effects of gas velocity, bed particle diameter and bed height on PM and smoke filtration efficiencies and pressure drops. A theoretical work has been also conducted for further investigation of the effects of the mentioned parameters on PM filtration. The experimental results show that the fluidized-bed DPF provides high PM filtration efficiency and low-pressure drop especially under lower gas flow rates. Smaller diameter bed particles provide higher filtration efficiency under the low gas flow rate ; however, the filtration efficiency drastically decreases with the increase in gas flow rate due to excessive fluidization of the bed particles. The increase in bed height gives higher PM filtration efficiency while it causes an increase in pressure drop. The calculation results indicate that the diffusion collection is a dominant mechanism for PM filtration under the conditions of this study. The lower PM filtration ratios at high exhaust gas flow rates are caused by reduction of the filtration efficiency in diffusion collection.