Catalyzing filters and methods of making
Assignee3M Innovative Properties Company
InventorsRyan C. Shirk, Thomas E. Wood, Yuji Ishikami
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Abstract
Catalyzing filters and methods for placing catalyst onto filter media, which involve positioning the catalyst at locations on the filter media where materials to be catalyzed will make contact during the filtering process.
Claims32
A method of manufacturing a catalyzing filter medium suitable for use in an engine exhaust, the method comprising:
- providing a filter medium suitable for use in an engine exhaust;
- providing a catalyst system comprising a catalyst material and a liquid;
- dispersing the catalyst system in a gaseous medium so as to form a gaseous catalyst dispersion;
- and
- flowing the gaseous catalyst dispersion into the filter medium such that the gaseous medium flows through the filter medium and at least some of the catalyst material and liquid deposits on surfaces of the filter medium.
A catalyzing filter medium suitable for use in an engine exhaust, said filter medium comprising:
- a porous body suitable for use in an engine exhaust;
- catalyst material concentrated at locations in said porous body where material to be catalyzed flowing into said filter medium will contact said catalyst material,
- wherein said filter medium comprises a lower concentration of said catalyst material at locations in said filter medium where the material to be catalyzed flowing into said filter medium will not contact said porous body.
A catalyzing filter medium suitable for use in an engine exhaust, said filter medium having a thickness and comprising a catalyst material for catalyzing a reaction of exhaust particles flowing into said filter medium, said filter medium having a concentration profile of said catalyst material across said thickness reflecting a concentration profile of exhaust particles that occurs when the exhaust particles become deposited in said filter medium during use of said filter medium in an engine exhaust.
A catalyzing filter medium suitable for use in an engine exhaust, said filter medium comprising an inlet surface, an interior surface and an outlet surface, said filter medium having a concentration of a catalyst material at said inlet surface, a relatively lower concentration of said catalyst material at said interior surface, and a lowest concentration of said catalyst material at said outlet surface.
Dependencies are inferred from the claim text.