Apparatus for treating diesel exhaust gases

Abstract

The invention relates to an apparatus for treating diesel exhaust gases including a diesel particulate filter. The invention also relates to a method for manufacturing and using such an apparatus. A particulate filter (DFP) according to the invention has a coating, there is used a sol having the average particle size of the particles below 100 nm, preferably below 50 nm and that a particulate oxidation and that a particulate oxidation catalyst (POC) has been connected in front of the particulate filter in relation to the flow direction of the exhaust gas, which includes at least partially open channels for leading the exhaust gas.

1 . An apparatus for treating diesel exhaust gases comprising a diesel particulate filter (DPF), characterized in that it comprises coating manufactured with sol whose average particle size is below 100 nm, preferably below 50 nm and that a particulate oxidation catalyst (POC) has been connected in front of the particulate filter in relation to the flow direction of the exhaust gas, which comprises at least partially open channels for leading the exhaust gas. 
   
   
       2 . A treatment apparatus according to  claim 1 , characterized in that the particulate oxidation catalyst (POC) and/or the diesel particulate filter (DPF) comprises woven or meshlike metal sheets. 
   
   
       3 . A treatment apparatus according to  claim 1 , characterized in that the particulate oxidation catalyst (POC) comprises corrugated sheets situated crosswise in relation to each other, in which the smocking direction is in angle with the average flow direction of the exhaust gas (G). 
   
   
       4 . A treatment apparatus according to  claim 1 , characterized in that the apparatus is near the engine in the exhaust pipe system, such as in C-C-position. 
   
   
       5 . A treatment apparatus according to  claim 1 , characterized in that the particulate oxidation catalyst (POC) comprises manufactured with sol whose average particle size is below 100 nm, preferably below 50 nm. 
   
   
       6 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises aluminum, titanium, silicon, cerium, zirconium and/or manganese oxides. 
   
   
       7 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises an aluminum and titanium sol, where Al 2 O 3 :TiO 2 =3:1-10:1, preferably 5:1-8:1. 
   
   
       8 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises an aluminum and silicon sol, where Al 2 O 3 :SiO 2 =1:1-4:1. 
   
   
       9 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises a cerium and zirkonium sol, where CeO 2 :ZrO 2 =100:1-1:100, preferably 20:1-1:1. 
   
   
       10 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises a cerium and titanium sol, where CeO 2 :TiO 2 =10:1-2:1. 
   
   
       11 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises a cerium and manganese sol, where CeO 2 :MnO 2 =10:1-1:1, preferably within the range of 4:1-2.1. 
   
   
       12 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises iron, cobalt, nickel, copper, vanadium, tungsten, borium, tin, gallium, indium, lanthanum, prasedium and/or niobium oxides. 
   
   
       13 . A treatment apparatus according to  claim 1 , characterized in that the dry matter content in the sol is within the range 0.1-30% by weight, preferably within the range 0.5-10% by weight. 
   
   
       14 . A treatment apparatus according to  claim 1 , characterized in that the sol comprises water, organic solvent and/or surface active sol stabilizing agent. 
   
   
       15 . A treatment apparatus according to  claim 1 , characterized in that the coating is manufactured in 1-3 coating cycles by using the same sol or various different sols in each coating cycle. 
   
   
       16 . A treatment apparatus according to  claim 1 , characterized in that in the coating, there is added, as a catalytically active component, platinum, rhodium, iridium, palladium, ruthenium and/or silver, by adsorption or along with the sols. 
   
   
       17 . A treatment apparatus according to  claim 16 , characterized in that the quantity of active component in the coating is within the range 0.01-50% by weight, preferably within the range 0.1-5% by weight. 
   
   
       18 . A treatment apparatus according to  claim 1 , characterized in that in the sol, one or several components are added in solution form. 
   
   
       19 . A treatment apparatus according to  claim 1 , characterized in that the sol viscosity is 1-20 cP, preferably 5-10 cP. 
   
   
       20 . A treatment apparatus according to  claim 1 , characterized in that in the particulate filter, there are added particles with a relatively large surface area, such as preferably the following compounds: Al 2 O 3 , TiO 2 , SiO 2 , CeO 2  or ZrO 2 . 
   
   
       21 . A treatment apparatus according to  claim 1 , characterized in that the particulate filter is suction dried. 
   
   
       22 . Use of a treatment apparatus for treating exhaust or waste gases, characterized in that the an apparatus according to  claim 1  is used for collecting and oxidating of exhaust particles with NO 2 . 
   
   
       23 . A method for manufacturing a treatment apparatus equipped with a particulate filter used in the treatment of exhaust or waste gases, characterized in that the particulate filter is coated by a sol or a sol mixture having the average particle size of the particles below 100 nm, preferably below 50 nm and that a particulate oxidation catalyst (POC) is connected in front of the particulate filter in relation to the flow direction of the exhaust gas, which comprises at least partially open channels for leading the exhaust gas. 
   
   
       24 . A method according to  claim 23 , characterized in that the apparatus is arranged near the engine in the exhaust pipe system, such as to C-C-position. 
   
   
       25 . A method according to  claim 23 , characterized in that in the particulate oxidation catalyst (POC) comprises catalytic corrugated metal sheets crossed in relation to each other, in which the direction of corrugation of the folds is in angle with the average flow direction of the exhaust gas (G). 
   
   
       26 . A method according to  claim 23 , characterized in that the oxidation catalyst (POC) and/or particulate filter (DPF) comprises meshlike metal sheets. 
   
   
       27 . A method according to  claim 23 , characterized in that the particulate oxidation catalyst (POC) has a coating, there is used a sol having the average particle size of the particles below 100 nm, preferably below 50 nm.