Gaseous emissions treatment structures with induction heating
A gaseous emissions treatment assembly has a honeycomb ceramic substrate body with a plurality of cells for passage of exhaust gases. Respective lengths of metal wire are located in a number of the cells. An induction heating coil is mounted adjacent the substrate body for generating a varying electromagnetic field, thereby inductively to heat the lengths of wire and thereby to heat the substrate body.
1. An assembly for treating gaseous emissions comprising a honeycomb ceramic substrate body having a plurality of cells, a first set of the plurality of cells for the passage of emissions gas, discrete lengths of metal wire located in respective ones of each of a second set of the plurality of cells, and an induction heating coil mounted adjacent the substrate body for generating a varying electromagnetic field, to thereby inductively heat the discrete lengths of wire and to thereby heat the substrate body and the emissions gas.
2. The assembly as claimed in claim 1 , wherein at least some of the discrete lengths of metal wire are held in the respective cells of the second set thereof by a bonding material to bond the metal wire lengths to the interior surfaces of the respective cells.
3. The assembly as claimed in claim 1 , wherein at least some of the discrete lengths of metal wire are held in the respective cells of the second set thereof by a friction fit.
4. The assembly as claimed in claim 3 , at least one of the discrete lengths of metal wire formed with a non-linear element, at least a part of the non-linear element bearing against bounding surfaces of the respective cells of the second set thereof.
5. The assembly as claimed in claim 1 , the metal being a ferromagnetic metal.
6. The assembly as claimed in claim 1 , further comprising a layer of material immediately outside the coil for limiting electromagnetic field radiated outside the assembly when the varying electromagnetic field is generated at the coil.
7. The assembly as claimed in claim 1 , further comprising a layer of material immediately outside the coil for increasing inductive coupling between the coil and the discrete lengths of metal wire when the varying electromagnetic field is generated at the coil.
8. The assembly as claimed in claim 1 , the cells bounded by walls of the honeycomb ceramic substrate body, the walls coated with catalyst-containing material for promoting a pollution-reducing chemical reaction.
9. The assembly as claimed in claim 1 , at least one of the discrete lengths of metal wire being one of round, square, hexagonal and triangular cross-section.
10. The assembly as claimed in claim 1 , the cells of said plurality thereof in a regular array and having a cell density across the substrate body of from 400 to 900 cells per square inch.
11. The assembly as claimed in claim 1 , further comprising a temperature sensor mounted at the substrate body and connected into a circuit for providing feedback to a control system for controlling an engine operable to generate the gaseous emissions to be treated.
12. A process for treating gaseous emissions comprising passing the gaseous emissions through a first set of a plurality of cells in a honeycomb ceramic substrate body, and generating a varying electromagnetic field in an induction heating coil mounted adjacent the honeycomb ceramic substrate body to thereby inductively heat discrete lengths of metal wire located in respective ones of a second set of the plurality of cells, thereby to heat the ceramic substrate body and the passing gaseous emissions.
13. The process as claimed in claim 12 , wherein at least one of the discrete lengths of wire is held in a respective cell of the second set thereof by a bonding material to bond said discrete length of metal wire to the interior surface of the cell.
14. The process as claimed in claim 12 , wherein at least one of the discrete lengths of metal wire is held in a respective cell of the second set thereof by a friction fit.
15. The process as claimed in claim 12 , further comprising generating the varying electromagnetic field when an engine operable to generate the gaseous emissions to be treated is operating and when the ceramic substrate body is below a predetermined threshold temperature.
16. The process as claimed in claim 12 , further comprising generating the varying electromagnetic field for a period before start-up of an engine operable to generate the gaseous emissions to be treated.