Particulate matter processing apparatus

Abstract

Aggregation of the particulate matter is facilitated. A particulate matter processing apparatus ( 1 ) comprises an electrode ( 5 ) which is provided in an exhaust gas passage ( 3 ) of an internal combustion engine, which extends from a wall surface of the exhaust gas passage ( 3 ) toward an inner side of the exhaust gas passage ( 3 ), which is bent at a bent portion ( 51 ) toward an upstream side or a downstream side in a flow direction (B) of an exhaust gas, and which extends toward the upstream side or the downstream side in the flow direction (B) of the exhaust gas, wherein the electrode ( 5 ) is formed so that a field intensity, which is provided between the electrode ( 5 ) and the wall surface of the exhaust gas passage ( 3 ) on the upstream side, is larger than that provided on the downstream side.

1 . A particulate matter processing apparatus comprising an electrode which is provided in an exhaust gas passage of an internal combustion engine, which extends from a wall surface of the exhaust gas passage toward an inner side of the exhaust gas passage, which is bent at a bent portion toward an upstream side or a downstream side in a flow direction of an exhaust gas, and which extends toward the upstream side or the downstream side in the flow direction of the exhaust gas, wherein:
 the electrode is formed so that a field intensity, which is provided between the electrode and the wall surface of the exhaust gas passage on the upstream side, is larger than that provided on the downstream side.   
     
     
         2 . The particulate matter processing apparatus according to  claim 1 , further comprising:
 a power source which supplies an electric power to the electrode, wherein:   the power source supplies the electric power to one portion of the electrode to apply an identical voltage to the entire electrode.   
     
     
         3 . The particulate matter processing apparatus according to  claim 1 , wherein:
 the electrode is provided with a plurality of protruding portions which extend toward a wall surface side of the exhaust gas passage in a direction perpendicular to the flow direction of the exhaust gas at a part extending toward the upstream side or the downstream side of the flow direction of the exhaust gas; and   the field intensity between the electrode and the wall surface of the exhaust gas passage is changed by changing at least one of a distance between the protruding portion and the wall surface of the exhaust gas passage or an installation spacing in the flow direction of the exhaust gas between the protruding portions, between the upstream side and the downstream side of the flow of the exhaust gas.   
     
     
         4 . The particulate matter processing apparatus according to  claim 3 , wherein the exhaust gas passage, which is disposed around the electrode, has an identical inner diameter, and the field intensity between the electrode and the wall surface of the exhaust gas passage is changed by changing at least one of a length of the protruding portion and the installation spacing in the flow direction of the exhaust gas between the protruding portions. 
     
     
         5 . The particulate matter processing apparatus according to  claim 4 , wherein:
 the electrode extends from the bent portion toward the downstream side in the flow direction of the exhaust gas; and   a length of the protruding portion is short and the installation spacing in the flow direction of the exhaust gas between the protruding portions is short at a portion which is disposed far from the bent portion as compared with a portion which is disposed near to the bent portion.   
     
     
         6 . The particulate matter processing apparatus according to  claim 4 , wherein:
 the electrode extends from the bent portion toward the upstream side in the flow direction of the exhaust gas; and   a length of the protruding portion is long and the installation spacing in the flow direction of the exhaust gas between the protruding portions is long at a portion which is disposed far from the bent portion as compared with a portion which is disposed near to the bent portion.   
     
     
         7 . The particulate matter processing apparatus according to  claim 3 , wherein a thickness of the protruding portion is changed between the upstream side and the downstream side of the flow of the exhaust gas. 
     
     
         8 . The particulate matter processing apparatus according to  claim 1 , further comprising:
 a detecting unit which detects a current allowed to pass through the electrode;   a judging unit which judges whether or not a pulse current is generated in the current detected by the detecting unit; and   a control unit which reduces an application voltage applied to the electrode as compared with that provided at a present point in time if it is judged by the judging unit that the pulse current is generated.