ECOCAT ®SUBSTRATE WITH AIR GAP INTEGRATED CANNING FOR LD DIESEL

To meet ever tightening exhaust emission limits, a new canning system for metallic substrates was developed. The developed system includes half shells that have tortuous locking tongues and integrated air gap insulation. The metallic EcoCat^® type substrate is a self-supporting light matrix, having channel shape corresponding to channels of half shells which lock its longitudinal movement and, more importantly breaks the boundary layer and forces gas flow to swirl, improving the heat and mass transfer. With the developed canning principle a complete catalytic converter can be produced by using only three components. The new design has been found especially suitable for light duty diesel applications in which it is essential to ensure maximum working temperature also for the outermost channel layers which are close to the half shells. Two EcoCat^® substrates were canned so that the reference product was without air gap between the half shells and the second product by using the new canning principle with integrated air gap insulation. The substrate channel inside temperatures were monitored in the centerline of the product and at the outermost channel layer from end face of substrates during FTP-75, ECE + EUDC and Indian driving cycles. EURO-2 and EURO-3 level turbo charged light duty diesel vehicles were used for emission tests. The new type of product showed improved conversion efficiency especially during the urban driving phase.