Origin

China

With popularity of diesel engine automobiles, the particulate from emission, mainly containing carbon, enhances the air pollution . The US Environmental Office promulgated the particulate regulation for diesel engine in 1980, stipulating the particulate in diesel passenger car's emission should meet the criterion of less 2.0 gram per mile. The diesel particulate filter (DPF) is able to filter above 80% carbon smoke particulate .For practical application, it would be a great help to solve the problem of air pollution in city. The basic working principle of PDF is that If the DPF is coated with noble metal (such as Pt, Pd and Rh), black smoke with carbon particulate from diesel engine ,passes through a special tube and enters the filter. The carbon smoke particulate is absorbed to the filter made of metallic fibre felt, when passing the inner dense set and bag-style filter. When particulate absorption reaches to certain degree, the tail burner would be ignited to burn automatically. In this case, the absorbed particulate is burned out and turned into nontoxic CO2 then discharges. The full device is designed as double room structure, and filtration and recycle are going in different areas, making them non-disturbed. The system can work automatically whatever working condition the engine in. The special filter made by honeycomb ceramic, in some extent, can capture the carbon particle which diameter is less than 30 micron. Characteristic : Large and compact area per unit volume. Small pressure loss and excellent capturing performance. Excellent heat resistance and heat shock resistance. If the DPF is coated with noble metal (such as Pt, Pd and Rh), The particulate of emission is captured inside thin gas hole or entrance. As it lasts, the cumulated layer becomes thicker and thicker, and pressure loss increases. To ensure the performance of engine, when pressure loss reaches to some extent, the filter must be regenerated. The regeneration is to make the particulate burning, by raising the gas temperature of filter. The particulate condition is related to the oxygen concentration. Normally, it is burning at 550-650 ??.It's adopted to raise emission temperature by adjusting throttle, and increase gas temperature with burner. The particulate burning temperature can be decreased by catalyzer. Such device makes cumulative particulate burned as soon as possible, thus recover the pressure loss and fitter's performance, then the filter is regenerated.