PURPOSE: To prepare an exhaust gas filter capable of being regenerated by a reduced quantity of energy, excellent in heat stress resistance and having durability by using a raw material wherein a ratio of a heat-resistant inorg. fiber to an inorg. powder is different and by changing the densities on the exhaust gas inflow and outflow sides of a honeycomb structure.
CONSTITUTION: A slurry wherein a ratio of a heat-resistant inorg. fiber such as an alumina-silica fiber or an alumina fiber to an inorg. powder such as sericite clay or silica is adjusted in a range of 1-2, pref., 1.3-1.7 is supplied to a papermaking machine in a different compounding ratio so as to be distributed laterally and formed into a ceramic sheet. A corrugated sheet and a flat sheet are produced from the ceramic sheet and bonded to be formed into a honeycomb structure. By this constitution, the densities on the inflow and outflow sides of exhaust gas of this honeycomb structure are mutually different. Since the density of the ignition surface of soot at the time of the regeneration of a filter is low, heat conductivity is low and heat diffusion is reduced and energy allowing soot to reach ignition temp. is reduced. The combustion of soot is stabilized and, since the filter becomes high in density toward the rear part thereof, the filter is high in strength.
MURANO YUICHI
WADA SHINJI
NAGAI NOBUAKI
WATANABE KOICHI
MATSUEDA SEI
IKEDA YUKINORI
