This content is not included in your SAE MOBILUS subscription, or you are not logged in.
A New Metallic Catalyst
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 04, 2002 by SAE International in United States
Annotation ability available
To meet ever tightening exhaust emission limits, improved engines and exhaust gas after treatment systems must be developed. The principal trend is to install the catalytic converter as close as practically possible to the engine to hasten light-off performance of the catalyst. A second trend is to reduce the thermal mass of the converter by reducing wall thickness of the substrate, and thirdly, increasing the cell density to improve mass and heat transfer from the bulk gas to the catalyst surface.
At the same time, demands for improved mechanical durability of the converter are required. These improvements most not only withstand higher temperatures but also higher accelerations caused by engine vibration and exhaust gas pulsation.
A new type of metallic substrate is introduced to meet more stringent requirements. The essential feature of the substrate is that flow channel is not straight and is specifically designed to keep the gas flow partly turbulent and mixed instead of the traditional laminar flow pattern. This factor improves heat and mass transfer.
Essentially, using thinner shell material reduces thermal mass and this has become possible with a new shell structure. These improvements mean that the converter can be warmed up to normal operating temperatures very quickly. The new substrate has excellent mechanical durability and superior performance durability compared to that of conventional metallic and ceramic substrates.
Theoretical calculations related to mechanical durability, mass and heat transfer together with practical emission and mechanical durability tests are presented.
CitationTuomola, H., Lylykangas, R., Matilainen, P., and Lievonen, A., "A New Metallic Catalyst," SAE Technical Paper 2002-01-0357, 2002, https://doi.org/10.4271/2002-01-0357.
- www.unifrax.com., unifrax Product Information Sheet
- Määttänen M. and Lylykangas R., Mechanical Strength of a Metallic Catalytic Converter Made of Pre-coated Foil
- Määttänen M. and Avikainen T., Metallic Catalytic Converter Cross Axis Strength Considerations
- Luoma M., Lappi P. and Lylykangas R., Evaluation of High Cell Density Z-Flow Catalyst
- Luoma M., Härkönen M., Lylykangas R. and Sohlo J., Optimisation of the Metallic Three-Way Catalyst Behaviour
- Chandrupatala T.R.. Belegandu A. D.. Introduction To Finite Elements In Engineering. Present Hall, Engelwood Cliffs, New Jersey 07632
- Elspass W. Dr.. Design of high precision sandwich structure using analytical and finite element models. MSC World User's Conference Los Angeles, California March 26 - 30, 1990.
- Woodmansee Paul R. Master Student, Gans Howard D. Ph.D, Assistant Professor of Aerospace Engineering Air Force Institute of Technology. Finite Element Analysis of Porosity on Material Properties Using MSC/Nastran.
- Collier Craig S., P.E and Spoth Kevin A. Lockheed Engineering and Sciences Co. Thermomechanical Finite Element Analysis of Stiffened Unsymmetric Composite Panels With Two Dimenssional Models. NASA Langley research Center Hampton, VA.
- MSC/Nastran The Nastran Theoretical Manual Level 15.5. The Mac Neal-Schwendler Corporation
- Nagel Thomas, Diringer Joachim. Emitec GmbH Lohmar. Minimum Test Requirements for High Cell-Density, Ultra-Thin Wall Catalyst Supports; Part I.
- Brück Rolf, Diewald Robert, Maus Wolfgang, Wieres Ludwig, Kaiser Friedrich-Wilhelm. Emitec GmbH Lohmar. New Ultra Thin Wall Metal Catalyst for Close-Coupled Applications.
- Nagel Thomas, Maus Wolfgang and Breuer Jürgen, Emitec GmbH Lohmar. Development of more Exacting Test Conditions for Close-Coupled Converter Applications.