Apparatus and method for gaseous emissions treatment using front end induction heating
An assembly for treating gaseous emissions includes a substrate body having a front and a rear and cells for the passage of emissions gas. Inductance heating metal is located in the substrate body and an induction heating coil is mounted adjacent the substrate body for generating a varying electromagnetic field for inductively heating the metal and thereby heating the substrate body. A greater concentration of the metal is located near the front of the substrate body than near the rear.
1. An assembly for treating gaseous emissions comprising a substrate body having a front end, a rear end, a plurality of cells for the passage of emissions gas, inductance heating metal located in the substrate body, and an induction heating coil mounted adjacent the substrate body for generating a varying electromagnetic field, thereby inductively to heat the metal and thereby to heat the substrate body, wherein a greater concentration of the metal is located near the front end of the substrate body than near the rear end of the substrate body;
wherein the inductance heating metal is respective lengths of metal wire located in each of a first set of the plurality of cells; and
wherein at least some of the lengths of metal wire are wire segments shorter than the full length of the substrate body.
2. The assembly of claim 1 , wherein, the inductance heating metal is confined to a front part of the substrate body and the induction heating coil is mounted adjacent only a front part of the substrate body.
3. The assembly of claim 1 , wherein end portions of the lengths of wire project from a front face of the substrate body at the front end.
4. The assembly of claim 3 , wherein the induction heating coil extends beyond said front face so that a part thereof is mounted adjacent the projecting wire end portions.
5. The assembly of claim 3 , wherein the projecting wire end portions taper towards the ends of the wires.
6. The assembly of claim 3 , wherein at least two of the projecting wire end portions are joined to each other by a spiral heating element wherein the element is mounted in front of the front face for inductive heating thereof by the induction coil.
7. The assembly as claimed in claim 3 , wherein wire segments are located at the front of the substrate body but not at the back of the substrate body, the induction heating coil mounted adjacent the substrate body at the front of the assembly.
8. The assembly as claimed in claim 3 , wherein wire segments in a first subset of the first set of cells are longer than wire segments in a second subset of the first set of cells.
9. The assembly, of claim 1 , there being a greater concentration of wire per unit volume of the substrate body towards the center of the substrate body than at the perimeter thereof.
10. The assembly as claimed in claim 1 , the metallic composition of one wire being different from the metallic composition of at least one other wire.
11. The assembly as claimed in claim 1 , the substrate body made of a ceramic honeycomb material.
12. The assembly as claimed in claim 1 , the metal being a ferromagnetic metal.
13. The assembly as claimed in claim 1 , the wires having one of a hollow and an open cross-section configuration.
14. A process for treating gaseous emissions using an assembly having an induction coil mounted adjacent a substrate body, the substrate body having a plurality of cells for the passages of emissions gas, inductance heating metal located in the substrate body with a greater concentration of the inductance heating metal being located near a front end of the substrate body than near a rear end of the substrate body, wherein the inductance heating metal is respective lengths of metal wire located in each of a first set of the plurality of cells and wherein at least some of the lengths of metal wire are wire segments shorter than the full length of the substrate body and an induction heating coil mounted adjacent the substrate body, the method comprising passing gaseous emissions along the cells, generating a varying electromagnetic field at the coil thereby to cause induction heating of the metal, heat from the heating heated metal being transferred to the substrate body and to the gaseous emissions passing along the cells, the heating being greater at the front end of the substrate body than at the rear end thereof.
15. The process as claimed in claim 14 , walls of the cells having a catalyst surface layer, the induction heating acting to heat the layer to promote a catalytic reaction in the gaseous emissions passing along the cells.
16. The process as claimed in claim 15 , the catalytic reaction being an exothermic reaction.
17. The process as claimed in claim 14 , further comprising generating the varying electromagnetic field when an engine which is the source of the emission gases is operating and when the substrate body is below a predetermined threshold temperature.
18. The process as claimed in claim 14 , further comprising generating the varying electromagnetic field for an engine which is to be the source of the emission gases before start-up of the engine.
19. The process as claimed in claim 14 , further comprising inductively preheating gaseous emissions before the gaseous emissions enter the substrate body.