Increasingly stringent emission regulations require diesel engines to use necessary after-treatment purification devices while using clean fuel and in-machine purification. The particulate filter (DPF) is the most commonly used after-treatment technology to deal with PM emissions.
The main part of DPF is the filter carrier, which is mainly divided into two categories according to materials: ceramic base and metal base. Ceramic-based DPF carrier materials include cordierite, silicon carbide, mullite, zirconia, etc.; metal-based DPF carrier materials include sintered metal, foam metal, metal mesh, etc. Currently, the most commonly used filter materials are cordierite and silicon carbide.
The design structures of DPF include wall flow type, fluid type, etc. The most common one is wall flow type. This type of DPF usually adopts a cylindrical ceramic structure, forming many small, parallel channels in the axial direction. Different from the general flow-through structure of the collector, the wall-flow filter element structure selects any one of the two ends to block in the channel adjacent to the filter layer, thereby forcing the exhaust gas to pass through the porous wall to achieve the capture of particulate matter.
