| 摘要 |
The purpose of the present invention is to provide a honeycomb filter capable of converting (purifying) exhaust gases and CO generated during the regenerating process by catalytic reaction: that is, a honeycomb filter comprising a pillar-shaped honeycomb fired body having a large number of cells longitudinally disposed in parallel with one another with a cell wall therebetween, with either one end of each of the cells sealed,
the honeycomb filter allowing gases having flowed in through either one end face side to flow out from the other end face side,
wherein
an outlet-side catalyst supporting area with a catalyst supporting layer formed from an end face on a gas outlet side of the honeycomb filter toward an end face on a gas inlet side of the honeycomb filter, the catalyst supporting layer having a catalyst supported thereon;
an inlet-side catalyst supporting area with a catalyst supporting layer formed from an end face on the gas inlet side of the honeycomb filter toward an end face on the gas outlet side of the honeycomb filter, the catalyst supporting layer having a catalyst supported thereon; and
a catalyst unsupporting area with no catalyst supporting layer formed between the outlet-side catalyst supporting area and the inlet-side catalyst supporting area, said catalyst unsupporting area having no catalyst supported thereon, are provided,
a thermal conductivity of the catalyst unsupporting area is higher than thermal conductivities of the outlet-side catalyst supporting area and the inlet-side catalyst supporting area, and
Y (%), Z (%), and X (%) satisfy the following inequalities (1) to (4): 1 ‰ Y ‰ 19 880 - 70 �¢ Y / 9 ‰ Z ‰ ( 825 - 15 �¢ Y ) / 9 1 ‰ Y ‰ 10 330 - 15 �¢ Y / 9 ‰ Z ‰ ( 1375 - 70 �¢ Y ) / 9 10 ‰ Y ‰ 19 X = 100 - Y - Z Y (%) indicating a ratio of a length of the outlet-side catalyst supporting area in a longitudinal direction of the honeycomb filter to an entire length of the honeycomb filter in the longitudinal direction of the honeycomb filter,
Z (%) indicating a ratio of a length of the inlet-side catalyst supporting area in the longitudinal direction of the honeycomb filter to the entire length of the honeycomb filter in the longitudinal direction of the honeycomb filter, and X (%) indicating a ratio of a length of the catalyst unsupporting area in the longitudinal direction of the honeycomb filter to the entire length of the honeycomb filter in the longitudinal direction of the honeycomb filter. |
