Collection of Particulate Matters in Diesel Exhaust Gas by Uneven Potential Distribution Created along a Dielectric Surface

A novel type of an electrostatic precipitator, in which dielectric surface works as a collection electrode, has been developed as a technique to collect and decompose soot in exhaust gas from incineration devices including diesel engines. In an experiment using real exhaust gas, a biased AC high voltage was applied to the discharge electrode attached on the glass surface intermittently so that the potential was 0 V at the discharge electrode and a at certain positive value on the glass surface. This variation in the potential along the surface generated electric fields that led particles selectively to the glass surface, avoiding their adhesion on discharge electrode. As a result, a PM removal efficiency of 0.64 (1.0 means 100%) was obtained for 42 NL/min of exhaust gas. Numerical simulation was performed to find charged particle trajectories in the PM reactor. The results on particle adhesion area and removal efficiencies obtained agreed with those in the experiment.