Apparatus, vehicle and method

Abstract

An apparatus is provided for the catalytic treatment of exhaust gas from an internal combustion engine comprising: a. a casing having an exhaust gas inlet and a treated exhaust gas outlet; b. a heater disposed within the casing, through which exhaust gas may flow; and c. a catalyst article disposed within the casing adjacent to the heater, through which exhaust gas can flow; wherein the heater comprises an electrically resistive wire mounted on an electrically insulating frame.

1 . An apparatus for the catalytic treatment of exhaust gas from an internal combustion engine comprising:
 a. a casing having an exhaust gas inlet and a treated exhaust gas outlet; and   b. a heater disposed within the casing, through which exhaust gas can flow;   c. a catalyst article disposed within the casing adjacent to the heater, through which exhaust gas can flow;   wherein the heater comprises an electrically resistive wire mounted on an electrically insulating frame.   
     
     
         2 . An apparatus as claimed in  claim 1  wherein the casing comprises a metallic sleeve. 
     
     
         3 . The apparatus as claimed in  claim 1  wherein the catalyst article is selected from a diesel particulate filter (DPF), a lean NOx trap (LNT), a lean NOx catalyst (LNC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a catalysed soot filter (CSF), a selective catalytic reduction filter (SCRF™) catalyst, an ammonia slip catalyst (ASC), a cold start catalyst (dCSC), a gasoline particulate filter (GPF) and a three-way catalyst (TWC). 
     
     
         4 . The apparatus as claimed in  claim 1  wherein the catalyst article is disposed downstream of the heater. 
     
     
         5 . The apparatus as claimed in  claim 1  wherein the electrically resistive wire comprises an electrically resistive metal or metal alloy. 
     
     
         6 . The apparatus as claimed in  claim 5  wherein the electrically resistive wire comprises silver, gold, platinum, rhodium, ruthenium, iron, chrome, titanium or an alloy of one or more thereof. 
     
     
         7 . The apparatus as claimed in  claim 6  wherein the electrically resistive wire comprises a metal alloy comprising nickel and chromium. 
     
     
         8 . The apparatus as claimed in  claim 7  wherein the electrically resistive wire is a Nichrome wire. 
     
     
         9 . The apparatus as claimed in  claim 6  wherein the electrically resistive wire comprises a metal alloy comprising nickel and titanium. 
     
     
         10 . The apparatus as claimed in  claim 1  wherein the electrically resistive wire has a substantially circular cross-section having a diameter in the range ≥0.1 to ≤2 mm, preferably ≥0.2 to ≤1.5 mm. 
     
     
         11 . The apparatus as claimed in  claim 1  wherein the electrically insulating frame comprises an annular member and one or more cross-members. 
     
     
         12 . The apparatus as claimed in  claims 1  wherein the electrically insulating frame comprises a disc having a plurality of channels extending therethrough. 
     
     
         13 . The apparatus as claimed in  claims 1  wherein the electrically insulating frame takes the form of a static mixer, wherein the catalyst article is an SCR catalyst and is disposed downstream of the heater, and wherein the apparatus further comprises a means for introducing urea or ammonia precursor into the casing upstream of the heater. 
     
     
         14 . The apparatus as claimed in  claim 1  wherein the electrically insulating frame comprises a ceramic substrate. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . The apparatus as claimed in  claim 1  wherein the frame comprises catalytic material. 
     
     
         18 . The apparatus as claimed in  claim 17  where the frame comprises a ceramic substrate having a coating of catalytic material. 
     
     
         19 . The apparatus as claimed in  claim 1  wherein the axial length of the casing is greater than or equal to the sum of the axial length of the electrically insulating frame and the axial length of the catalyst article, and wherein the axial length of the catalyst article is greater than the axial length of the electrically insulating frame. 
     
     
         20 . The apparatus as claimed in  claim 19  wherein the axial length of the frame is less than 15% of the axial length of the catalyst article, preferably less than 10%. 
     
     
         21 . A method of catalytically treating an exhaust gas from an internal combustion engine, which method comprises passing the exhaust gas through an apparatus comprising:
 a. a casing having an exhaust gas inlet and a treated exhaust gas outlet;   b. a heater disposed within the casing, through which exhaust gas can flow; and   c. a catalyst article disposed within the casing adjacent to the heater, through which exhaust gas can flow;   
       wherein the heater comprises an electrically resistive wire mounted on an electrically insulating frame. 
     
     
         22 . (canceled) 
     
     
         23 . A vehicle comprising an internal combustion engine and an apparatus for the catalytic treatment of exhaust gas from the internal combustion engine, which apparatus comprises:
 a. a casing having an exhaust gas inlet and a treated exhaust gas outlet;   b. a heater disposed within the casing, through which exhaust gas can flow; and   c. a catalyst article disposed within the casing adjacent to the heater, through which exhaust gas can flow;   
       wherein the heater comprises an electrically resistive wire mounted on an electrically insulating frame. 
     
     
         24 . (canceled)