Diesel Particulate Trap of Corrugated Honeycomb Fabricated with Mullite Fiber Ceramics 860010
High temperature capability filter traps have typically been employed for the collection of the solid particulates from the diesel exhaust (1,2,3,4,5,6)*. Our efforts have concentrated on trying to apply the sintered textile structure of ceramic fibers as filtering elements of diesel particulate traps, Mullite fiber ceramics is prepared by sintering as composites of Mullite fibers and silica-alumina clay. Mullite fiber ceramics has a porosity of up to 80%. Generally the higher porosity trap element would exhibit lower filtration efficiency (7). However, diesel particulate traps composed of the porous Mullite fiber ceramics show significantly high filtration efficiency of around 75%. Mullite has a higher working temperature than Cordierite, but its relatively larger thermal expansion coefficient (5.0×10−6/°C) results in poor thermal shock resistivity. Nevertheless, the thermal shock resistivity of Mullite fiber ceramics is extraordinarily improved by its very high porosity of up to 80% and its textile structure. As diesel particulates accumulate on the porous textile structure of Mullite fiber ceramics, the back pressure rise rate is fairly low. This paper describes some characteristics, performance and evaluation of the Mullite fiber ceramic diesel particulate trap of corrugated honeycomb.