Abstract: A heat/acoustic wave conversion component having a first end face and a second end face, includes a partition wall that defines a plurality of cells extending from the first end face to the second end face, inside of the cells being filled with working fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the working fluid and energy of acoustic waves resulting from oscillations of the working fluid. Hydraulic diameter HD of the heat/acoustic wave conversion component is 0.4 mm or less, where the hydraulic diameter HD is defined as HD=4×S/C, where S denotes a cross-sectional area of each cell perpendicular to the cell extending direction and C denotes a perimeter of the cross section, and the heat/acoustic wave conversion component has three-point bending strength of 5 MPa or more.

Abstract: The honeycomb filter includes a honeycomb substrate having porous partition walls defining a plurality of cells and plugging portions. In a cross section, the cells are arranged so that a periphery of an inlet plugged cell including an open end whose shape is a square in which a length of one side is L1 is surrounded with four rectangular outlet plugged cells each including an open end whose shape is a rectangle in which a length of one side is L1 and a length of the other side is L2 (L1>L2) and four square outlet plugged cells each including an open end whose shape is a square in which a length of one side is L2. A partition wall center distance a, a partition wall center distance b and a partition wall thickness t satisfy the following equation (1): 0.95<b/at<1.90 ??(1).

Abstract: A heat/acoustic wave conversion component includes a plurality of monolithic honeycomb segments each including a partition wall that defines a plurality of cells extending between both end faces, and the plurality of monolithic honeycomb segments each mutually converts heat exchanged between the partition wall and the working fluid in the cells and energy of acoustic waves resulting from oscillations of the working fluid. In the heat/acoustic wave conversion component including the plurality of honeycomb segments each being monolithic configured, hydraulic diameter HD of the cells is 0.4 mm or less, open frontal area of the honeycomb segments is 60% or more and 93% or less, heat conductivity of the honeycomb segments is 5 W/mK or less, and a ratio HD/L of the hydraulic diameter HD to the length L of the honeycomb segment is 0.005 or more and less than 0.02.

Abstract: A heat/acoustic wave conversion component includes a partition wall that defines a plurality of cells, inside of the cells being filled with fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the fluid and energy of acoustic waves resulting from oscillations of the fluid. The plurality of cells have an average of hydraulic diameters HDs that is 0.4 mm or less in a plane perpendicular to the cell extending direction, the heat/acoustic wave conversion component has an open frontal area at each end face of 60% or more and 93% or less, and distribution of hydraulic diameters HDs of the plurality of cells has relative standard deviation that is 2% or more and 30% or less.

Abstract: A heat/acoustic wave conversion unit includes a heat/acoustic wave conversion component and two heat exchangers. Hydraulic diameter HD of the cells in the heat/acoustic wave conversion component is 0.4 mm or less, and a ratio HD/L of HD to the length L of the heat/acoustic wave conversion component is from 0.005 to 0.02. One of the heat exchangers includes a heat-exchanging honeycomb structure and an annular tube that surrounds a circumferential face of the heat-exchanging honeycomb structure. The annular tube includes a structure body that is disposed in the channel to increase a contact area with the heated fluid, an inflow port into which the heated fluid flows, and an outflow port through which the heated fluid flows out. At least one of the heat-exchanging honeycomb structure and the structure body is made of a ceramic material that contains SiC as a main component.

Abstract: In a cross section perpendicular to a central axis direction of the honeycomb substrate, cells are arranged so that a periphery of an inlet plugged cell is surrounded with four rectangular outlet plugged cells and four square outlet plugged cells, and in the cross section, a partition wall center distance a, a partition wall center distance b and a partition wall thickness t satisfy the following equation (1). Additionally, an amount of a catalyst per unit volume of partition walls which is loaded onto the partition walls defining the rectangular outlet plugged cells and the inlet plugged cells is larger than an amount of a catalyst per unit volume of the partition walls which is loaded onto the partition walls defining the rectangular outlet plugged cells and the square outlet plugged cells 0.95<b/at<1.90??(1).

Abstract: A heat/acoustic wave conversion unit includes a heat/acoustic wave conversion component and two heat exchangers. Hydraulic diameter HD of the cells in the heat/acoustic wave conversion component is 0.4 mm or less, and a ratio HD/L of HD to the length L of the heat/acoustic wave conversion component is from 0.005 to 0.02. One of the heat exchangers includes a heat-exchanging honeycomb structure and an annular tube that surrounds a circumferential face of the heat-exchanging honeycomb structure. The annular tube includes a structure body that is disposed in the channel to increase a contact area with the heated fluid, an inflow port into which the heated fluid flows, and an outflow port through which the heated fluid flows out. At least one of the heat-exchanging honeycomb structure and the structure body is made of a ceramic material that contains SiC as a main component.

Abstract: A heat/acoustic wave conversion component includes a partition wall that defines a plurality of cells, inside of the cells being filled with fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the fluid and energy of acoustic waves resulting from oscillations of the fluid. The plurality of cells have an average of hydraulic diameters HDs that is 0.4 mm or less in a plane perpendicular to the cell extending direction, the heat/acoustic wave conversion component has an open frontal area at each end face of 60% or more and 93% or less, and distribution of hydraulic diameters HDs of the plurality of cells has relative standard deviation that is 2% or more and 30% or less.

Abstract: A heat/acoustic wave conversion component having a first end face and a second end face, includes a partition wall that defines a plurality of cells extending from the first end face to the second end face, inside of the cells being filled with working fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the working fluid and energy of acoustic waves resulting from oscillations of the working fluid. Hydraulic diameter HD of the heat/acoustic wave conversion component is 0.4 mm or less, where the hydraulic diameter HD is defined as HD=4×S/C, where S denotes a cross-sectional area of each cell perpendicular to the cell extending direction and C denotes a perimeter of the cross section, and the heat/acoustic wave conversion component has three-point bending strength of 5 MPa or more.

Abstract: A heat/acoustic wave conversion component includes a plurality of monolithic honeycomb segments each including a partition wall that defines a plurality of cells extending between both end faces, and the plurality of monolithic honeycomb segments each mutually converts heat exchanged between the partition wall and the working fluid in the cells and energy of acoustic waves resulting from oscillations of the working fluid. In the heat/acoustic wave conversion component including the plurality of honeycomb segments each being monolithic configured, hydraulic diameter HD of the cells is 0.4 mm or less, open frontal area of the honeycomb segments is 60% or more and 93% or less, heat conductivity of the honeycomb segments is 5 W/mK or less, and a ratio HD/L of the hydraulic diameter HD to the length L of the honeycomb segment is 0.005 or more and less than 0.02.

Abstract: In a cross section perpendicular to a central axis direction of the honeycomb substrate, cells are arranged so that a periphery of an inlet plugged cell is surrounded with four rectangular outlet plugged cells and four square outlet plugged cells, and in the cross section, a partition wall center distance a, a partition wall center distance b and a partition wall thickness t satisfy the following equation (1). Additionally, an amount of a catalyst per unit volume of partition walls which is loaded onto the partition walls defining the rectangular outlet plugged cells and the inlet plugged cells is larger than an amount of a catalyst per unit volume of the partition walls which is loaded onto the partition walls defining the rectangular outlet plugged cells and the square outlet plugged cells. 0.95<b/at<1.

Abstract: The honeycomb filter includes a honeycomb substrate having porous partition walls defining a plurality of cells and plugging portions. In a cross section, the cells are arranged so that a periphery of an inlet plugged cell including an open end whose shape is a square in which a length of one side is L1 is surrounded with four rectangular outlet plugged cells each including an open end whose shape is a rectangle in which a length of one side is L1 and a length of the other side is L2 (L1>L2) and four square outlet plugged cells each including an open end whose shape is a square in which a length of one side is L2. A partition wall center distance a, a partition wall center distance b and a partition wall thickness t satisfy the following equation (1): 0.95<b/at<1.90 ??(1).

Abstract: A ceramics structure body having chemical composition of 42 to 56 wt % of SiO2, 30 to 45 wt % of Al2O3 and 12 to 16 wt % of MgO, crystalline phase mainly composed of cordierite, a porosity of 55 to 65%, an average pore size of 15 to 30 &mgr;m; and the total area of pores exposed on surfaces of partition walls constituting the honeycomb ceramics structure body being 35% or more of the total area of partition wall surfaces. Fifteen to 25 wt % of graphite and 5 to 15 wt % of a synthetic resin are added as a pore forming agent to a cordierite-forming raw material; the resultant is kneaded and molded into a honeycomb shape; and the resultant is dried and fired to produce above-mentioned honeycomb ceramics structure body. According to this honeycomb ceramics structure body, a low pressure loss and a high collection efficiency can be attained.

Abstract: A honeycomb structure in which the structure has a reinforced part having been loaded with a cordierite powder at least on one end surface of the frontal openings of the substrate of a honeycomb structure made of cordierite. This honeycomb structure does not decrease merits of a small pressure loss and the like as a thin-walled honeycomb structure, and is also excellent in abrasive resistance of the end surfaces of the frontal openings.

Abstract: A ceramics structure body having chemical composition of 42 to 56 wt % of SiO2, 30 to 45 wt % of Al2O3 and 12 to 16 wt % of MgO, crystalline phase mainly composed of cordierite, a porosity of 55 to 65%, an average pore size of 15 to 30 &mgr;m; and the total area of pores exposed on surfaces of partition walls constituting the honeycomb ceramics structure body being 35% or more of the total area of partition wall surfaces. Fifteen to 25 wt % of graphite and 5 to 15 wt % of a synthetic resin are added as a pore forming agent to a cordierite-forming raw material; the resultant is kneaded and molded into a honeycomb shape; and the resultant is dried and fired to produce above-mentioned honeycomb ceramics structure body. According to this honeycomb ceramics structure body, a low pressure loss and a high collection efficiency can be attained.

Abstract: The raw materials for forming a cordierite composition are dissolved into water with a dispersing agent to prepare a slurry, and the thus prepared slurry is passed through the sieve having a mesh of 45 &mgr;m or less. After that, the slurry after sieving is dried by means of the spray drying to obtain dry powders, and the batch for forming is obtained by using the dry powders. Or, the batch for forming is obtained by the filter pressing. That is to say, the batch for forming is obtained by using the raw material powders which are passed through the sieve in a wet state. Therefore, it is possible to prevent agglutination of the raw material particles and to remove the coarse raw material particles effectively. As a result, if the extrusion molding is performed by using the thus obtained batch for forming, it is possible to form the ceramic honeycomb structural body having an extremely thin wall thickness with no defects.

Abstract: A filter for exhaust gas purification has a honeycomb structure made of a porous ceramic material and having a large number of channels, both given channels at one end of the honeycomb structure and the remaining channels at the other end of the honeycomb structure being plugged so as to be able to use the partition walls of the honeycomb structure surrounding the channels, as a filter layer for exhaust gas, wherein the thickness of the partition walls is 250 &mgr;m or less, the porosity is 40% or more, the average pore diameter is 3 to 7 &mgr;m, and the volume of the pores having diameters of 10 &mgr;m or more is 20% or less relative to the volume of the total pores. This exhaust gas purification filter has improved trapping efficiency for fine solid particulates of 0.08 &mgr;m or less while giving rise to no increase in pressure loss.

Abstract: A honeycomb structure in which the structure has a reinforced part having been loaded with a cordierite powder at least on one end surface of the frontal openings of the substrate of a honeycomb structure made of cordierite. This honeycomb structure does not decrease merits of a small pressure loss and the like as a thin-walled honeycomb structure, and is also excellent in abrasive resistance of the end surfaces of the frontal openings.

Abstract: The raw materials for forming a cordierite composition are dissolved into water with a dispersing agent to prepare a slurry, and the thus prepared slurry is passed through the sieve having a mesh of 45 &mgr;m or less. After that, the slurry after sieving is dried by means of the spray drying to obtain dry powders, and the batch for forming is obtained by using the dry powders. Or, the batch for forming is obtained by the filter pressing. That is to say, the batch for forming is obtained by using the raw material powders which are passed through the sieve in a wet state. Therefore, it is possible to prevent agglutination of the raw material particles and to remove the coarse raw material particles effectively. As a result, if the extrusion molding is performed by using the thus obtained batch for forming, it is possible to form the ceramic honeycomb structural body having an extremely thin wall thickness with no defects.

Abstract: A honeycomb regenerator is constructed by (a) honeycomb structural bodies arranged in a high temperature portion, in which a temperature is over 1250° C. during a normal operation, made of aluminum-titanate or a combination of aluminum-titanate and mullite, and (b) honeycomb structural bodies arranged in a low temperature portion, made of cordierite and/or mullite, or by (a) honeycomb structural bodies arranged in a high temperature portion, to which an exhaust gas having a high temperature is contacted, made of aluminum-titanate or a combination of aluminum-titanate and mullite, (b) honeycomb structural bodies arranged in a middle temperature portion made of alumina and (c) honeycomb structural bodies arranged in a low temperature portion made of one material or a combination of materials selected from a group of cordierite, mullite and a porcelain.