Composite catalytic converter

A composite polycellular catalytic converter for removing pollutants from an exhaust gas stream comprising (a) a housing, (b) a polycellular electrically heatable catalytic converter comprising a monolith core formed of nonnesting corrugated thin metal strips overfolded once at their midpoints and in electrically conducting relation with an electrically conducting central core located at the midpoint of each strip, and said metal strips being wound in a spiral about said central core to form a polycellular bundle, the free ends of each overfolded strip being electrically conducting, a binder ring in electrical contact with said free ends for binding the wound strips into a polycellular core, means for conducting electrical power from a voltage source to said electrically heatable catalytic core, (c) a polycellular conventional ceramic catalytic monolith in juxtaposed coaxial relation downstream of said electrically heatable catalytic converter, and (d) means for holding said conventional ceramic catalytic monolith in fixed axial relation in said housing.