Electrically heated catalytic apparatus

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, comprising an electrically conductive catalyst carrier including laminated metal sheets having insulation layers formed on the surfaces thereof, the catalyst carrier including local hot spots which are electrically heated, wherein the local hot spots include deformations in edge portions of adjacent laminated metal sheets which are in contact with an adjacent metal sheet to nullify the insulation layers so that adjacent metal sheets are electrically joined at the deformations through the nullified insulation layers and wherein the carrier includes an upstream potion and a downstream portion and the hot spots are located in the upstream portion.

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, comprising an electrically conductive catalyst carrier, including an upstream portion and a downstream portion, the carrier including a plurality of laminated metal sheets and a corresponding plurality of insulation layers, wherein an insulation layer is disposed between adjacent laminated metal sheets and wherein each insulation layer includes a plurality of notches and wherein edge portions of the adjacent laminated metal sheets have deformations that bend toward each other through the notches of each insulating layer so that each laminated metal sheet is electrically joined through the notches to an adjacent laminated metal sheet, and wherein edge portions of adjacent laminated metal sheets are joined to each other only in the upstream portion of the carrier.

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, comprising an electrically conductive catalyst carrier, having an upstream portion and a downstream portion, the carrier including laminated metal sheets, each laminated metal sheet including an insulation layer formed thereon, wherein adjacent laminated metal sheets coupled together by brazing, and wherein a first brazing material is used in a first portion of the catalyst carrier and a second brazing material is used in a second portion of the catalyst carrier, and wherein a resistance of the first brazing material is different from the resistance of the second brazing material to form electrically heated hot spots in the second portions of the catalyst carrier, the second portions of the carrier being located in the upstream portion of the carrier.

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, the apparatus comprising an electrically conductive catalyst carrier, having an upstream portion and a downstream portion, the carrier including laminated metal sheets, first portions of each laminated metal sheet including an insulation film formed thereon, wherein second portions of each metal sheet include no insulation film thereon wherein the second portions of adjacent metal sheets are coupled to each other to form electrically heated local hot spots, and wherein the hot spots are located only in the upstream portion of the carrier.

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, the apparatus comprising an electrically conductive catalyst carrier having an upstream portion and a downstream portion, the carrier including a plurality of layered metal sheets, each metal sheet having an insulating layer formed on first portions of the surface of the metal sheet, wherein at least one of the metal sheets is corrugated and wherein the insulating layer has been removed from second portions of the surfaces of each metal sheet and adjacent sheets are electrically connected to each other at predetermined positions within the second portions, and wherein the second portions are located only in the upstream portion of the carrier.

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, the apparatus comprising a catalytic carrier including an upstream portion and a downstream portion, the carrier being made of an electrically conductive material, wherein the upstream portion of the carrier is provided with localized electrically heatable spots, the apparatus further including an exhaust gas biasing means for channelling the flow of exhaust gas from the portion of the carrier including the electrically heatable spots to an unheated portion of the carrier.

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, the apparatus comprising an electrically conductive catalytic carrier including layers of metal panels, wherein each panel comprises a corrugated sheet coupled to a flat sheet, and wherein each flat sheet includes a plurality of projections protruding from a surface of the panel, and wherein adjacent panels are electrically connected to each other at the projections, and wherein adjacent panels are electrically connected to each other only in the upstream portion of the carrier.

An electrically heated catalytic apparatus, through which exhaust gas flows from an upstream end to a downstream end, the apparatus comprising a catalytic carrier having an upstream portion and a downstream portion and including layers of laminated metal panels, wherein each panel includes a metal corrugated sheet coupled to a flat sheet, wherein each corrugated sheet includes at least one crest having a projection protruding from a surface of the panel, and wherein adjacent panels are electrically connected to each other at the projections only in the upstream portion of the carrier.