CYLINDRICAL POROUS BODY

To provide a cylindrical porous body, which can make both strength and gas permeability compatible.SOLUTION: A cylindrical porous body comprises a cylindrical ceramic having gas cavities and dents formed thereon, which includes a plurality of specific air cavities in which a length of a first line segment is above or equal to 30 μm and a ratio of the length of the first line segment to a length of a second line segment is above or equal to 3, on a cross section including a central axis of the ceramic, where the longest line segment of line segments joining two points on a visible outline of the air cavities is defined as the first line segment and the longest line segment which is orthogonal to the first line segment is defined as the second line segment. Further the cylindrical porous body includes a plurality of specific dents in which a length of a third line segment is above or equal to 30 μm and a ratio of the length of the third line segment to a length of a fourth line segment is above or equal to 3, where the longest line segment of the line segments joining two points on an outer peripheral edge of the dents is defined as the third line segment and the longest line segments which is orthogonal to the third line segment is defined as the fourth line segment. An average length of the third line segment in the plurality of specific dents is above or equal to 110% of an average length of the first line segment in the plurality of specific air cavities.SELECTED DRAWING: Figure 3 【課題】 筒状多孔質体において、強度とガス透過性とを両立させる技術を提供する。【解決手段】 筒状多孔質体は、気孔と窪みが形成されている筒状のセラミックを備え、セラミックの中心軸を含む断面において、気孔の外形線上の２点を結ぶ線分のうち、最も長い線分を第１線分とし、第１線分に直交する最も長い線分を第２線分とすると、第１線分の長さが３０μｍ以上であり、かつ、第２線分の長さに対する第１線分の長さの比が３以上である特定気孔を複数含んでおり、窪みの外周縁上の２点を結ぶ線分のうち、最も長い線分を第３線分とし、第３線分に直交する最も長い線分を第４線分とすると、第３線分の長さが３０μｍ以上であり、かつ、第４線分の長さに対する第３線分の長さの比が３以上である特定窪みを複数含んでおり、複数の特定窪みの第３線分の平均長さは、複数の特定気孔の第１線分の平均長さの１１０％以上である。【選択図】 図３