Particle filter devices

Abstract

A device for reducing pollution of an internal combustion engine, including a collection of monolithic elements of honeycomb type connected by a jointing compound, each element incorporating a set of adjacent cells of mutually parallel axes separated by porous walls, which cells are plugged by plugs at one or other of their ends to delimit inlet chambers opening onto a gas intake face and outlet chambers opening onto a gas discharge face such that gas that is to be filtered passes through the porous walls, the collection being inserted in a metal casing by a compacted fibrous mat. A jointing compound has a three-point flexural modulus of rupture of between 0.5 and 6 MPa, the jointing compound has a dynamic Young's modulus less than or equal to 17 GPa, the mat has a mean density in the compacted state of between 0.30 and 0.54, and the mean thickness of the mat in the compacted state is between 2 and 8 mm.

1 - 11 . (canceled) 
     
     
         12 . A device for reducing pollution of an internal combustion engine, comprising:
 a collection of monolithic elements of honeycomb type connected by a jointing compound, each element incorporating a set of adjacent cells of mutually parallel axes separated by porous walls, which cells are plugged by plugs at one or other of their ends to delimit inlet chambers opening onto a gas intake face and outlet chambers opening onto a gas discharge face such that gas that is to be filtered passes through the porous walls, the collection being inserted in a metal casing by a compacted fibrous mat,   wherein the jointing compound has a three-point flexural modulus of rupture of between 0.5 and 6 MPa,   wherein the jointing compound has a dynamic Young's modulus less than or equal to 17 GPa,   wherein the mat has a mean density in a compacted state of between 0.30 and 0.54,   wherein the mean thickness of the mat in the compacted state is between 2 and 8 mm.   
     
     
         13 . The device as claimed in  claim 12 , wherein the modulus of rupture is between 1 and 5 MPa, or is between 2 and 4 MPa. 
     
     
         14 . The device as claimed in  claim 12 , wherein the dynamic Young's modulus is less than or equal to 10 GPa. 
     
     
         15 . The device as claimed in  claim 12 , wherein the mean density in the compacted state is less than or equal to 0.50. 
     
     
         16 . The device as claimed in  claim 12 , wherein the porous walls are made of a ceramic material based on silicon carbide (SiC). 
     
     
         17 . The device as claimed in  claim 16 , wherein thermal conductivity of the jointing compound is greater than or equal to 0.1 W/m·K between 20 and 800° C. 
     
     
         18 . The device as claimed in  claim 12 , wherein the mean thickness of the jointing compound is between 0.5 and 4 mm. 
     
     
         19 . The device as claimed in  claim 12 , wherein the monolithic elements are assembled by partial bonding. 
     
     
         20 . The device as claimed in  claim 12 , wherein the density in the compacted state and/or the thickness of the mat is non-uniform, such that the density of the mat is lower than the mean density and/or the thickness of the mat is higher than the mean thickness in contact with regions where thermomechanical stresses may become concentrated during regeneration phases. 
     
     
         21 . The device as claimed in  claim 20 , wherein the thickness of the mat in the compacted state at peripheral regions of the filter subjected to a highest thermomechanical stresses is at least 20%, or is at least 50%, or at least 100% higher than the thickness of the mat at peripheral regions subjected to lowest thermomechanical stresses, and/or the density of the mat in the compacted state at the peripheral regions of the filter subjected to the lowest stresses is at least 20%, or is at least 50%, or at least 100% higher than the density in the regions subjected to the highest stresses. 
     
     
         22 . The device as claimed in  claim 12 , further comprising a catalytic coating to treat polluting gases of CO or HC and/or NOx type.