CPC F01N 3/2013 (2013.01) [F01N 3/027 (2013.01); F23G 7/00 (2013.01); H05B 3/48 (2013.01); F01N 2240/16 (2013.01); F01N 2450/22 (2013.01); H05B 2203/014 (2013.01); H05B 2203/022 (2013.01)] | 20 Claims |
1. An exhaust gas heating unit for an exhaust system of an internal combustion engine, the exhaust gas heating unit comprising:
a tubular housing comprising an outer peripheral wall defining a tubular shape and having an interior hollow space; and
a heating element that has a first end and a second end and extends longitudinally between the first end and the second end to form a spiral shape within the interior hollow space, wherein the heating element comprises:
an external sheath, the external sheath formed of a thermally conductive material;
an electrically conductive resistance element that extends longitudinally within the external sheath; and
electrically insulating material disposed about the resistance element between the resistance element and the sheath; and
a heat transfer member positioned within the interior hollow space, the heat transfer member being formed from one or more strips of thermally conductive material,
wherein the one or more strips contact the external sheath at a plurality of locations between the first end and the second end, and
wherein the heat transfer member has a corrugated shape that follows the spiral shape of the heating element.
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