Honeycomb structure, method for manufacturing honeycomb structure, and exhaust gas purification system using honeycomb structure

A method for manufacturing a honeycomb structure comprising a plurality of through channels extending in an axial direction of the honeycomb structure, porous partition walls separating through channels one another, and plugging portions;

• said plugging portion plugging predetermined through channels at one end and the rest of through channels at other end opposite to the plugged end of the predetermined through channels, wherein a through-hole is formed in at least a part of the plugging portion, and a diameter of the through-hole is 0.2 mm or more, but not more than a value which is smaller between 1 mm and 75% of a diameter of an inscribed circle of the through channel;
• said method comprising the steps of:
• injecting a ceramic paste forming a plugging portion into predetermined through channels from one of their end faces;
• and
• subsequently subjecting either the ceramic paste thus injected or a plugging portion formed from the ceramic paste thus injected to a processing to form a through-hole in the plugging portion, wherein the processing to form a through-hole in the plugging portion is to spray a fluid onto the ceramic paste injected.

A method for manufacturing a honeycomb structure comprising a plurality of through channels extending to an axial direction of a honeycomb structure, porous partition walls separating through channels one another, and plugging portions;

• said plugging portion plugging predetermined through channels at one end and the rest of through channels at other end opposite to the plugged end of the predetermined through channels, wherein a through-hole is formed in at least a part of the plugging portion, and a diameter of the through-hole is 0.2 mm or more, but not more than a value which is smaller between 1 mm and 75% of a diameter of an inscribed circle of the through channel;
• said method comprising the steps of:
• mixing a melting point lowering component for lowering a melting point of cordierite into solvent to prepare a mixed solution;
• attaching the mixed solution to the end of the honeycomb structure of cordierite;
• and
• subsequently calcining the honeycomb structure to increase a thickness of a portion to which the mixed solution has been attached, so that the plugging portion including a through-hole is formed.

An exhaust gas purification system for trapping/collecting/removing particulate materials containing carbon as a major component included in dust-containing fluids of an internal combustion engine, the system comprising:

• a honeycomb structure comprising a plurality of through channels extending to an axial direction of the honeycomb structure, porous partition walls separating through channels one another, and plugging portions;
• said plugging portion plugging predetermined through channels at one end and the rest of through channels at other end opposite to the plugged end of the predetermined through channels, wherein a through-hole is formed in at least a part of the plugging portion, and a diameter of the through-hole is 0.2 mm or more, but not more than a value which is smaller between 1 mm and 75% of a diameter of an inscribed circle of the through channel, which is used as a filter for trapping/collecting the particulate materials;
• and
• heating means for burning the particulate materials trapped/collected by the honeycomb structure to regenerate a filtering capacity,
• wherein a through-hole in a plugging portion of the honeycomb structure is such a structure that the honeycomb structure is closed by the trapping/collecting and depositing of the particulate materials, that the closed through-hole opens by the burning of the particulate materials by heating at the time of the regeneration, and that at least some of unburnt materials such as ashes deposited in the honeycomb structure are discharged from the honeycomb structure with flow of the dust-containing fluids, when the through-hole opens, and wherein a sectional area of the through-hole of the plugging portion in the vicinity of an outer peripheral portion of the honeycomb structure is larger than that of the through-hole of the plugging portion in a central portion of the honeycomb structure.