| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent diesel particulate filters (DPF) for collecting and removing a particulate matter (PM) in exhaust emission from being clogged. <P>SOLUTION: A first DPF 16 and a second DPF 18 having different permeation hole diameters are respectively provided for an exhaust emission pipe 14 connected to an exhaust emission manifold 12 of the diesel engine 10 so that the permeation hole diameter becomes gradually smaller from upstream to downstream. With the large permeation hole diameter, the first DPF 16 has a function to collect only PMs of large particle size and facilitates low pressure loss. With the small permeation hole diameter, the second DPF 18 has a function to collect PMs of particle size larger than that of the second DPF. However, as the PMs of large particle size are removed by the first DPF 16, the second DPF 18 is not clogged in a relatively short period of time by the PMs of large particle size. Thus, it is possible to prevent clogging while suppressing rise in back pressure. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
