Heat isolated catalytic reactor

A catalytic reactor for use in an exhaust pipe carrying exhaust gases, the exhaust pipe having an interior wall, comprising:

• catalyst means for oxidizing selected constituents of the exhaust gases;
• a heat shield exterior to said catalyst means and having an interior wall and an exterior wall and a first end and a second end;
• mounting means for positioning said heat Shield within the exhaust pipe to create a first annular insulation space between the interior wall of the exhaust pipe and the exterior wall of said heat shield and for positioning said catalyst means within said heat shield to create a second annular insulation space between said catalyst means and the interior wall of said heat shield, wherein said mounting means comprises first and second mounting rings positioned at the first and second ends of said heat shield, respectively, said first and second mounting rings being adapted to receive and position said catalyst means and said heat shield to create the first and second annular insulation spaces;
• and
• heat insulating means exterior to said heat shield and interior to the first annular insulation space for reducing heat transfer between said catalyst means and the first annular insulation space.

A heat insulated catalytic reactor for use in an exhaust manifold of an internal combustion engine, comprising:

• an elongated cylindrically-shaped outer heat shield having a first end and second end separated by a cylindrically-shaped center section, said outer heat shield having a first annular mounting boss located at about the first end and a second annular mounting boss located at about the second end, said first and second mounting bosses being adapted to position and secure said outer heat shield in the exhaust manifold, said first and second mounting bosses also defining a first annular insulation space between said outer heat shield and the exhaust manifold;
• an elongated cylindrically-shaped inner heat shield having a first end and a second end separated by a cylindrically-shaped center section, the interior of said inner heat shield defining a catalyst cavity, and wherein said first and second ends have larger diameters than the cylindrically-shaped center section and are adapted to securely position and hold said inner heat shield within said outer heat shield, said first and second ends creating a second annular insulation space between said outer heat shield and said inner heat shield when said inner heat shield is positioned within said outer heat shield;
• a catalyst disposed within the catalyst cavity of said heat shield;
• and
• heat insulating means surrounding the cylindrically-shaped center section of said inner heat shield in the second annular insulation space for reducing heat transfer between said inner heat shield and said outer heat shield.