Honeycomb filter for exhaust gas decontamination and exhaust gas ...

(54) HONEYCOMB FILTER FOR EXHAUST GAS DECONTAMINATION AND EXHAUST GAS DECONTAMINATION APPARATUS

(76) Inventors: Noriyuki Taoka, Ibi-gun, Gifu (JP);

Yukio Oshimi, Ibi-gun, Gifu (JP)

Correspondence Address:

OBLON, SPIVAK, MCCLELLAND, MAIER &
NEUSTADT, PC.
1940 DUKE STREET
ALEXANDRIA, VA 22314 (US)

(21) Appl. No.: 10/506,438

(22) PCT Filed: Mar. 4, 2003
(86) PCT No.: PCT/JP03/02519

(30) Foreign Application Priority Data

Mar. 4, 2002 (JP) 200257887

Publication Classification

(51) Int. CI.7 BO ID 46/00

(52) U.S. CI 55/523

(57) ABSTRACT

A honeycomb filter for purifying exhaust gases that can almost completely burn and remove particulates accumulated on a wall portion by a regenerating process allowing residual ashes on the wall portion to easily move inside a through hole because the ashes are easily separated from the wall portion. In the honeycomb filter a columnar body made of porous ceramics, having parallel through holes in the length direction with a wall portion interposed therebetween, is designed so that part or all of the wall portion that separates the through holes from each other functions as a filter collecting particulates, wherein a length 1 of the longest side in a cross section perpendicular to the length direction of the through hole and a length L in the length direction of the columnar body satisfy: 60 = L/1 = 500, and a surface roughness Ra (according to JIS B 0601) of the through hole inner wall satisfies: Ra = 100 fim.