Developing an AC Low Voltage Electrostatic Filter For Motorcycle Exhaust System in Reducing Ultrafine Particle Emission

Particulate matters with the diameter less than $0.1\ \mu\mathrm{m}$, as known as ultrafine particles, are derived by the natural and anthropogenic sources. The ultrafine particle concentration in the ambient air has been increasing sharply due to the combustion processes, such as motor vehicles, cooking, smoking, biomass burning, and many others. Ultrafine particles have been identified as a toxic agent for human health and linked to many diseases. In this study, we developed a new technology of an ultrafine particle filtration system using an AC low voltage 12 Volt for motorcycles. For this purpose, three electrostatic filters: F1, F2, and F3 that were made of aluminum plates were tested under two different frequencies: low-frequency LF - 60 Hz and high-frequency HF - 1300 Hz. The purpose of this study was to obtain an efficient filter for motor particle emissions. There were three standard motorcycles used as the ultrafine particle sources. The concentration of ultrafine particles was measured using a TSI P-Trak Ultrafine Particle Counter Model 8525 in five sampling times. The efficiency of the filter determined as the ratio of the ultrafine particle concentrations emitted by the motorcycle samples before and after being equipped with filters. The highest efficiency, 35%, was found in the lowest gap 0.9 mm, with an LF frequency. Meanwhile, the lowest filter efficiency, 7%, was found in the frequency of HF, with the highest gap 3.6 mm. As a conclusion, the filter efficiency depended on the voltage frequency and the filter gap.