Diesel Exhaust Filtration using Electrostatic Precipitator with Air Distribution Plate

Abstract

The diesel engine is one of the most popular types of engine that is used in a variety of the ways such as in industrial plants, cars, buses, trucks, etc. The exhaust of a diesel engine, especially old vehicles, consists of particulate matter (PM) and toxic gases that can harm human health. The diesel particulate filter (DPF) is one of the widely used technologies that can reduce PM in the exhaust of a diesel engine. However, the DPF can cause fuel efficiency drop or engine damage due to the DPF blockage. For PM filtration, the electrostatic precipitator (ESP) is an efficient technology that uses electrostatic force to remove PM with low pressure drop and cleanability. Nonetheless, the filtration efficiency of the ESP drops abruptly for ultrafine PM and the high velocity of diesel exhaust. Therefore, this paper proposes an efficiency improvement technique for diesel exhaust filtration using ESP. An air distribution plate is applied to reduce exhaust velocity before entering the ESP that has a larger surface area. The shape and size of the opened area in the proposed air distribution plate are designed and simulated to achieve smooth airflow distribution throughout the ESP. A small-scale prototype is fabricated to investigate the airflow distribution and the filtration efficiency. After the performance confirmation, a full-scale prototype is designed for diesel vehicles. The experiment with a diesel pickup truck illustrates the PM removal efficiency improvement with an average efficiency of 79%.