| abstract |
A combustion engine catalytic converter comprises porous mesh sheet material made of metal fibers having a diameter of about 1-30 microns coated with a catalyst and formed into corrugations, the material having a void volume of preferably about 80-95 %. Adjacent sheets have corrugations in one example at 45° in opposite directions relative to the gas inlet and outlet flow directions. The sheets create turbulence creating a pressure drop across the sheet material and causing exhaust gas to flow through the sheet material interstices in contact with the catalyst in the interstices. The material is light weight, has low mass and exhibits good cold start up heating in less than 1 minute. The pressure drop across the converter, with turbulence in the gas flow, is comparable to honeycomb prior art converter structures exhibiting laminar flow, uses less catalyst, is more efficient and is lighter. Various embodiments are shown employing vortex generators for providing turbulence in addition to the zigzag corrugated channel orientation or to provide tortuous channel paths for the gas flow to create the desired turbulence. |