Ceramic honeycomb structure

Patent metadata

Field	Value
Publication number	US-10399074-B2
Application number	US-201615555759-A
Country	US
Kind code	B2
Filing date	Jan 26, 2016
Priority date	Mar 24, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A ceramic honeycomb structure comprising porous cell walls defining large numbers of flow paths, the cell walls having (a) porosity of 55% or more and less than 65%, and (b) 35,000/mm3 or more of substrate branches, wherein the number of substrate branches is defined by the number of branch points (including connecting points of 3 or more branches and connecting points of different-width branches) per a unit volume, in a network structure obtained by the skeletonization of the three-dimensional structure of cell wall substrates determined by X-ray CT.

First claim

What is claimed is:

1. A ceramic honeycomb structure comprising porous cell walls defining large numbers of flow paths, said porous cell walls having
(a) porosity of 55% or more and less than 65%, and
(b) 35,000/mm 3 or more of substrate branches, wherein the number of said substrate branches is defined by the number of branch points per a unit volume, in a network structure obtained by the skeletonization of the three-dimensional structure of said cell wall substrates determined by X-ray CT, wherein the branch points comprise connecting points of 3 or more branches and connecting points of different-width branches.

2. The ceramic honeycomb structure according to claim 1 , wherein the three-dimensional structure of said cell wall substrates determined by X-ray CT meets the formula of (d90−d10)/d50≤1.25, wherein
d10, d50 and d90 are substrate diameters at cumulative substrate volumes corresponding to 10%, 50% and 90% of the total substrate volume, in a substrate volume distribution against the diameter of said substrate unit;
one substrate unit is a substrate portion between two adjacent branch points, which has the substrate diameter and the substrate volume;
said substrate diameter is determined by halving a sum of short and long diameters of said substrate unit in its transverse cross section;
and
said cumulative substrate volume is determined by cumulating the substrate volume from the minimum substrate diameter to a particular substrate diameter.

3. The ceramic honeycomb structure according to claim 1 , wherein in the three-dimensional structure of said cell wall substrates determined by X-ray CT, a substrate diameter d50 at a cumulative substrate volume corresponding to 50% of the total substrate volume, which is determined from a substrate volume distribution against the diameter of said substrate unit, is 10-20 μm, wherein
one substrate unit is a substrate portion between two adjacent branch points, which has the substrate diameter and the substrate volume;
said substrate diameter is determined by halving a sum of short and long diameters of said substrate unit in its transverse cross section; and
said cumulative substrate volume is determined by cumulating the substrate volume from the minimum substrate diameter to a particular substrate diameter.

4. The ceramic honeycomb structure according to claim 1 , wherein in the three-dimensional structure of said cell wall substrates determined by X-ray CT, a substrate diameter d10 at a cumulative substrate volume corresponding to 10% of the total substrate volume, which is determined from a substrate volume distribution against the diameter of said substrate unit, is 8 μm or more, wherein
one substrate unit is a substrate portion between two adjacent branch points, which has the substrate diameter and the substrate volume;
said substrate diameter is determined by halving a sum of short and long diameters of said substrate unit in its transverse cross section; and
said cumulative substrate volume is determined by cumulating the substrate volume from the minimum substrate diameter to a particular substrate diameter.

5. The ceramic honeycomb structure according to claim 1 , wherein said ceramic is a cordierite-type ceramic.

Assignees

• Hitachi Metals Ltd

Inventors

• Okazaki Shunji

Classifications

• C04B38/00

  Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof (treating slag with gases or gas generating material C04B5/06 {; expanded graphite C04B35/536}) · CPC title

• C04B38/0074

  expressed as porosity percentage · CPC title

• F01N3/28

  Construction of catalytic reactors · CPC title

• C04B35/195 Primary

  Alkaline earth aluminosilicates, e.g. cordierite {or anorthite} · CPC title

• B01D53/94

  by catalytic processes · CPC title