Ceramic Hot Tubes: A Cost Effective Catalytic Converter for 2/3 Wheelers 990012

Ceramic Hot tubes are developed as a cost effective substrates for 2 and 3 wheelers Catalytic Converter. These are used instead of ceramic honeycomb substrates for the applications where, lower conversion is enough to meet the emission norms. Ceramic hot tubes are more appropriate for 4-stroke two wheelers which are marginally failing to meet Indian emission norms for year 2000. The low thermal expansion cordierite based ceramic hot tubes offer very high thermal shock resistance, high temperature strength, very low back pressure and adequate geometrical surface area. The unique design of this product can withstand severe thermal stresses up to 1200°C. This is required for long durability against mechanical vibrations and extraordinary temperature rise expected in Indian two and three wheelers. Hence ceramic hot tubes have advantage over metallic hot tubes.

Under the present work, two different configurations of ceramic hot tubes have been developed. They have surface area close to that of low cell density honeycombs, which is further increased by alumina wash coating. A catalyst coated hot tube was fitted in a 4-stroke motor cycle for evaluation of engine performance and mass emission. The properties of ceramic hot tube developed and its performance including mass emission under Indian driving cycle are presented in this paper.