Porous sheet and substrate having porous sheet(s) for treating exhaust gases of combustion engines

Abstract

A porous sheet for treating exhaust gases of combustion engines in open channels is disclosed. At least part of the porous sheet has a covering support having pores over 10 nm and coarse particles over 1.4 μm.

1 . A porous sheet for treating exhaust gases of combustion engines in open channels, comprising: 
 a porous sheet including a plurality of openings; and    a covering support, wherein the covering support covers at least a part of a surface of the porous sheet substrate, and    wherein the covering support has pores with a median pore size over 10 nm and a coarse particles with a median particle size over 1.4 μm.    
   
   
       2 . A porous sheet according to  claim 1 , wherein essentially all of the openings are filled by the covering support.  
   
   
       3 . A porous sheet according to  claim 1  wherein said porous sheet is a mesh sheet.  
   
   
       4 . A porous sheet according to claim,  3  wherein the mesh size of said mesh sheet is from 30 to 300.  
   
   
       5 . A porous sheet according to  claim 1 , wherein said porous sheet is a corrugated sheet.  
   
   
       6 . A porous sheet according to  claim 1 , wherein the median particle size is from 1.5 to 3.5 μm.  
   
   
       7 . A porous sheet according to  claim 1 , wherein the median pore size is over 5 nm.  
   
   
       8 . A porous sheet according to  claim 1 , wherein the median pore size is over 10 nm.  
   
   
       9 . A porous sheet according to  claim 1 , wherein said covering support comprises catalytically active material.  
   
   
       10 . A porous sheet according to  claim 1 , wherein said covering support comprises catalytically inert particles having a median particle size from 10 to 200 μm.  
   
   
       11 . A porous sheet according to  claim 1 , wherein said covering support comprises catalytically inert coarse alumina-, silica, zirconia-, ceria-or/and titania-particles.  
   
   
       12 . A porous sheet according to  claim 1 , wherein at least part of said covering support has been milled.  
   
   
       13 . A porous sheet according to  claim 1 , wherein an area mass of covering support is from 20 to 200 g/m 2 .  
   
   
       14 . A porous sheet according to  claim 1 , wherein a BET specific surface area of covering support is from 30 to 300 m 2 /g.  
   
   
       15 . A porous sheet according to  claim 1 , wherein said support comprises fibres, which are projecting out from a plane of said covering support.  
   
   
       16 . A metal substrate having open channels for treating exhaust gases of combustion engines, wherein said metal substrate comprises at least one porous sheet according to  claim 1 .  
   
   
       17 . A metal substrate according to  claim 16 , wherein said metal substrate comprises at least one other sheet.  
   
   
       18 . A metal substrate according to  claim 17 , wherein said other sheet is a smooth, perforated, mesh, wire mesh or fibrous sheet.  
   
   
       19 . A metal substrate according to  claim 17 , wherein said other sheet is a flat or corrugated sheet.  
   
   
       20 . A metal substrate according to  claim 17 , wherein said other sheet has been essentially covered with the covering support.  
   
   
       21 . A metal substrate according to  claim 17 , wherein said other sheet and porous sheet have been covered with the same covering support.  
   
   
       22 . A metal substrate according to  claim 17 , wherein at least one of said porous sheet and said other sheet comprises at least one of impressions and projections.  
   
   
       23 . A metal substrate according to  claim 16 , wherein, said metal substrate is at least one of a pre-oxicatalyst, a hydrolysis catalyst and a SCR oxicatalyst.  
   
   
       24 . A method for manufacturing a porous sheet for treating an exhaust gas of a combustion engine in open channels, the method comprising at least partially covering a porous sheet with a covering support having pores with a median pore size over 10 nm and coarse particles with a median particle size over 1.4 μm.  
   
   
       25 . A method for manufacturing a porous sheet according to  claim 24 , comprising filling essentially all openings of the porous sheet with the covering support.  
   
   
       26 . A method for manufacturing a metal substrate for treating exhaust gases of combustion engines, the method comprising joining at least one porous sheet according to  claim 1  to a metal substrate to form a plurality of open channels.  
   
   
       27 - 28 . (canceled)  
   
   
       29 . A method to purify impurity particles from an exhaust gas of a combustion engine, the method comprising contacting said exhaust gas to a surface of the porous sheet according to  claim 1 .  
   
   
       30 . A method to purify impurity particles from an exhaust gas of a combustion engine, the method comprising contacting said exhaust gas to a surface of the metal substrate according to  claim 16.