With the large numbers of diesel vehicles being used, carbon-based particulate from diesel engine exhaust increases the pollution of the environment. Many governments around the world release diesel particulate specification requirements. For diesel passenger vehicle, exhausting particles should be consistent with the specified value or less than 2.0 g / mile. The diesel engine exhaust particulate filter can filter out more than 80% of the soot particles, so if they can be practical applied, the urban air pollution problem will be greatly improved.

The basic principle

Diesel particulate filter (DPF) was spraying-coated by the metal platinum, rhodium, palladium, diesel engine exhaust containing carbon particles, black smoke, pass through a special pipeline into the engine’s internal-intensive exhaust particulate filter and bag filter, the soot particles are adsorbed on the metal fiber mat-like filter; when the adsorption capacity of the particles reaches a certain level, at the end of the device, the burner automatically ignites and starts to combust, soot particles in the above adsorption are burned and become harmless carbon dioxide to discharge to air. The entire device is designed for dual-chamber structure, filtration and regeneration partition, making the filtration and regeneration without disturbing each other, regardless of the engine in what conditions the system can work automatically. Specially made honeycomb ceramic - ceramic particulate filter play an important role to trap the particulate emissions to a certain extent.

The diesel particulate filter has the following characteristics:

1. Compact, each unit volume of filter has large specific surface area

2. Pressure loss low, excellent capture performance

3. Excellent heat and thermal shock resistance

Filter regeneration

If the diesel particulate filter is spray-coated by the metal platinum, rhodium or palladium, the diesel particulate emissions is first captured in the thin pores inside or at the entrance. With the extension of the time, the accumulation layer is thicker and the pressure loss increases, the filter must be "reborn," in order to ensure the performance of the engine when the pressure loss reaches a certain value. Filter regeneration is achieved by raising the gas temperature of the filter, so that the particles are burned. The Characters of the particles in diesel emissions is close related to the concentration of oxygen and they are usually burned in the 550 ~ 650 ° C.

Commonly, the exhaust temperature is increased by adjusting the throttle; the gas temperature is increased by burner and the particulate combustion temperature is reduced by catalyst, so that the accumulation of particles are burned as soon as possible, and the pressure loss is recovered, the function of the filter is restored, and the filter is regenerated.