Electrostatic precipitation of diesel PM at reduced gas temperature

Abstract

A diesel engine is one of the most fuel efficient engines and expected to save energy even it is necessary to remove particulate matter (PM) contained in the exhaust gas. Diesel particulate filter (DPF) has been established as a key technology in reducing diesel PM, however, technological improvements are still required to reduce pressure drop and to assure the regeneration. Therefore, we focused on an electrostatic precipitation by taking advantage of its small pressure drop and efficient collection of nano-sized particles. However, one of the problems with an electrostatic precipitator (ESP) is abnormal dust re-entrainment. To cope with this problem, we studied the effect of gas temperature on electrostatic precipitation of diesel PM and surface roughness of the collecting electrode. As a result, lower gas temperature showed stable collection and high collection efficiency of particles. In addition, varying the surface roughness of collecting electrode was effective for improving the collection efficiency by installing a metal mesh on it.