Particulate Filter

Abstract

A particulate filter is realized in a compact size which is adaptive to forced regeneration through addition of fuel and which can prevent white fume from being generated by excessive part of the fuel. A particulate filter 12 is disclosed which captures particulates entrained in exhaust gas 2 . Plug bodies 8 at inlets of a filter body 7 are arranged in passages and inwardly of an inlet edge of the filter body by predetermined distance, added-fuel oxidation catalyst 13 with enhanced performance of promoting oxidation reaction of the added fuel being carried in a region between the inlet edge of the filter body and arranged positions of the plug bodies 8 at the inlets. Plug bodies 9 at outlets of the filter body 7 are arranged in the passages and inwardly of an outlet edge o the filter body by predetermined distance, excess-fuel oxidation catalyst 14 with enhanced performance for promoting oxidation reaction of excess fuel remaining unreacted being carried in a region between arranged positions of the plug bodies 9 at the outlets and the outlet edge of the filter body.

1 . A particulate filter comprising a filter body made of porous material and having a great number of honeycomb passages through which exhaust gas passes, inlets and outlets of the passages being alternately clogged with plug bodies, respectively, the exhaust gas being caused to pass through thin porous walls compartmentalizing said passages so as to capture particulates entrained in the exhaust gas, characterized in that the plug bodies at the inlets are arranged in the passages and inwardly of an inlet edge on the filter body by predetermined distance, added-fuel oxidation catalyst with enhanced performance for promoting oxidation reaction of added fuel being carried in a region between said inlet edge of the filter body and arranged positions of the plug bodies at the inlets, and that the plug bodies at the outlets are arranged in the passages and inwardly of an outlet edge on the filter body by predetermined distance, excess-fuel oxidation catalyst with enhanced performance for promoting oxidation reaction of excess fuel remaining unreacted being carried in a region between arranged positions of the plug bodies at the outlets and the outlet edge of the filter body.  
   
   
       2 . A particular filter as set forth in  claim 1 , wherein carbon oxidation catalyst with enhanced performance for promoting carbon oxidation reaction of the captured particulates is carried in a region between arranged positions of the plug bodies at the inlets and those at the outlets.