JPH0812460A - Honeycomb ceramic structure - Google Patents

Abstract

PURPOSE:To obtain a honeycomb ceramic structure having high thermal shock resistance, capable of being constituted in any dimension and in a large size by laminating honeycomb ceramic modules of a fixed shape in the axial direction of their open cells. CONSTITUTION:This honeycomb ceramic structure 1 is constituted by laminating plural honeycomb ceramic modules 2 (cell walls 4) having fixed open cells 3 and fixed thickness in the axial direction of the open cells 3. The honeycomb ceramic modules 2 are generally a laminar or disklike shape. The honeycomb ceramic modules 2 have preferably >=10cm longer diameter L in the cross direction of the open cells 3, >=1mm thickness T in the axial direction of the open cells 3 and <=0.5T/L. A layer material for shock absorption having open cells is preferably arranged between the honeycomb ceramic modules 2 and/or the end face of the honeycomb ceramic structure 1 so as to absorb at least one of mechanical and/or thermal stress.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a honeycomb-shaped ceramic structure which is particularly excellent in thermal shock resistance and is suitable for use as a catalyst carrier. The major feature is that there is little pressure loss, and there is little horsepower loss in the engine. In addition, the structure has a large sound deadening effect, and is also environmentally friendly.

[0002]

2. Description of the Related Art A honeycomb-shaped ceramic structure has a large specific surface area and allows a fluid to flow through a through hole, and thus has been used as a catalyst carrier (exhaust gas purifying device) for automobiles or a chemical reaction catalyst carrier.

Particularly in the field of catalyst carriers for automobiles, which are required to have a material having a high thermal shock resistance and a structure, cordierite is crystallized by extrusion to form a honeycomb ceramic structure.

As a honeycomb-shaped ceramic structure and a manufacturing method, in addition to extrusion molding, in JP-A-48-66112, a flat ceramic sheet (ceramic material sheet) is processed to be uneven, and the uneven sheet is formed into cells (uneven parts). ) In the circumferential direction (direction in which the cross section is parallel to the surface forming the honeycomb) is stacked or rolled up and fired to obtain a honeycomb ceramic structure having open cells.

Also, in Japanese Patent Laid-Open No. 48-66112, a plurality of long tubular pipes forming open cells in a direction parallel to the surface forming the honeycomb are formed on a flat ceramic sheet (ceramic material sheet). Engage and fire,
It was a honeycomb-shaped ceramic structure provided with open cells.

In JP-A-57-179060,
In a porous ceramic structure having a three-dimensional mesh structure forming a large number of internal communication spaces communicating with the outside, rods from both ends of the structure in a plastic state,
A ceramic structure having an open (communication) cell is manufactured by forming a hole which does not penetrate the structure individually or mutually and has a three-dimensional mesh structure with the hole.

[0007]

However, in extrusion molding, the size of the structure obtained is limited. For example, an axially thick structure of an open cell is difficult to extrude because the flowability of the molding material decreases, and in order to obtain a structure with a large diameter, the mold must also be enlarged. did not become. In fact, the outer diameter of 10-15 cm was the limit.

Further, there is a problem that the capital investment amount of the extrusion molding apparatus is large, the yield of molded products is poor, and the raw material loss is large.

In addition, the structure in which the open cells are long (thickness) in the axial direction during use, for example, when used as a catalyst carrier for exhaust gas for automobiles, causes a rapid temperature rise locally, especially at the time of starting. There is a large temperature difference between the exhaust gas inlet and outlet,
The thermal shock was great. Therefore, the size of the structure is limited.

In the manufacturing process, in the honeycomb structure forming process in a state of having a predetermined plasticity, due to the limit of the self-holding force and the forming pressure, the structure having a large diameter or a long diameter has a thermal stress even when the ceramic is sintered. Therefore, it is difficult to manufacture a large-sized honeycomb-shaped ceramic structure because cracks, cracks or breakage easily occur, and the product yield decreases due to deformation due to large firing shrinkage.

Also, as the catalyst carrier, the conventional honeycomb-shaped ceramic structure is composed of one structure as a whole, so that it is difficult to support different catalysts. It required complicated steps.

In particular, the catalyst carrier for automobile exhaust gas is required to fulfill the functions of different properties (oxidation, reduction, and fine particle adsorption). Therefore, for example, unless a combustion condition of the engine and the temperature of the catalyst carrier are precisely controlled by using a three-way catalyst, the predetermined exhaust gas removal performance cannot be exhibited. However, since the above-mentioned conditions change at the time of starting or under high load, or depending on the outside temperature, it is necessary to remove all kinds of harmful substances under all operating conditions with a predetermined technical,
It was practically impossible under the constraints of space, time and cost. In particular, regarding the exhaust gas purifying device for diesel engines and large-sized engines, the technical solution is still unclear, but the solution is an urgent issue for environmental protection.

A first object of the present invention is to provide a honeycomb-shaped ceramic structure which is resistant to thermal shock, can be constructed in any size, and can be made large. As its use, for example, specifically, a catalyst carrier having high catalytic efficiency, a catalyst carrier for chemical reaction, an exhaust gas treatment device, a bioreactor, a waste water purification device, a drinking water purification device, especially an automobile exhaust gas catalyst carrier that can be used The purpose is to provide.

The second object of the present invention is to provide a plurality of functions in one structure.

A third object of the present invention is to provide an open cell structure having a high chemical reaction efficiency such as catalytic reaction or heat exchange efficiency, or a honeycomb ceramic structure fired from a raw material.

A fourth aspect of the present invention provides a structure of a honeycomb-shaped ceramic structure capable of reducing defects such as cracks and cracks at the time of forming and firing a honeycomb, that is, improving yield in manufacturing. Is an issue. The present invention is the fifth
Another object of the present invention is to provide a honeycomb-shaped ceramic structure for use in a purification device for exhaust gas, which can be applied to diesel engines such as large buses, large trucks, railways, power generation, and ships, and particularly large engines.

[0017]

The present invention achieves at least one of the above objects and problems. In the first aspect of the present invention, a honeycomb shape having a predetermined opening cell and a predetermined thickness is provided. A honeycomb ceramic structure is formed by stacking a plurality of ceramic modules in the axial direction of the open cells so as to communicate with each other in the axial direction of the open cells, and arranging a plurality of the honeycomb ceramic modules having a predetermined thickness ( Claim 1).

The predetermined open cells are the number of open cells, the open diameter, the open area per cross sectional area of the open cells, the ratio of the length or area of the cell wall to the cell, and the axis of the open cells. The shape in the direction includes a spiral shape, a zigzag shape, a step shape, a taper shape and the like having different three-dimensional shapes.

The module having a predetermined thickness includes a case where modules having different thicknesses are stacked.

[0020]

A second preferable means is the honeycomb-shaped ceramic structure according to the first means, wherein the honeycomb-shaped ceramic module has a plate shape or a disk shape. ).

A third preferable means is a large-sized and thin honeycomb-shaped ceramic structure having a transverse major axis L of the open-cells of the honeycomb-shaped ceramic module of 10 cm or more and an axial thickness T of the open-cells. Is 1 mm or more and T / L of thickness / major axis ratio is 0.5 or less.
A honeycomb-shaped ceramic structure according to the second means is provided (claim 3).

The fourth preferred means is that the other modules have different modules in the axial thickness of the open cell of the module, the outer diameter of the module, the form of the open cell, etc. A honeycomb-shaped ceramic structure which is the honeycomb-shaped ceramic structure according to any one of the means (claim 4).

A fifth preferred means is that the open-cells communicating with each other form a substantially spiral-shaped fluid passage, and the honeycomb-shaped ceramic structure according to any one of the first to fourth means. (Claim 5). The substantially helical shape includes the case where the flow path is formed in a step shape or a zigzag shape. Further, the fluid passing through the communicating open cells may form a substantially helical flow, and the communicating open cells themselves do not necessarily have to be substantially helical.

The sixth preferred means is to open or connect the honeycomb-shaped ceramic modules whose circular open-cell cross-sections are circular and are identical to each other in the circumferential direction of the open-cell cross-section coaxially or by stacking them alternately. The honeycomb-shaped ceramic structure according to any one of the first to fifth means, characterized in that the cells form a substantially helical fluid passage (claim 6).

A seventh preferable means is that a shock absorbing layer material is bonded between the modules or at the end of the structure, and the honeycomb ceramic structure according to any one of the first to sixth means. It is the body. The joining method is, for example, dipping, spraying, welding, welding, bonding, firing, fitting, or the like. The shock absorbing layer material is not limited to a normal elastic member such as a leaf spring, a disc spring, a coil spring, rubber, etc., and a metal such as the spring shape, a flat plate shape (layer shape), or a block shape, a semimetal (silicon etc.), or It may be an alloy (claim 7).

An eighth preferred means is the honeycomb-shaped ceramic structure according to any one of the first to seventh means, characterized in that the structure of the present invention is used as a catalyst carrier (claim 8). .

A ninth preferred means is the honeycomb-shaped ceramic structure according to the eighth means, wherein one module carries a catalyst different from other modules and exhibits different functions. Claim 9).

A tenth preferable means is the ninth means, in which at least one catalyst for mediating oxidation, reduction, and fine particle adsorption and decomposition is carried in at least one kind in a module constituting a structure. The honeycomb ceramic structure according to the eighth or ninth means is characterized in that (claim 9). It should be noted that a module that is, for example, a three-way catalyst carrier that performs all of the above three actions is also included in the scope of the present means.

The eleventh suitable means is a honeycomb-shaped ceramic structure according to any one of the eighth to tenth means, characterized in that it is a catalyst carrier for automobile exhaust gas which is particularly prone to thermal shock and mechanical shock. There is (claim 11).

A twelfth preferred means is a honeycomb-shaped ceramic structure according to any one of the first to eleventh means, characterized in that the modules are made of different ceramic materials. For example, cordierite and alumina. Furthermore, even if the same component is used, the case where the structure or crystal structure is different is included.

A thirteenth preferable means is that the raw material of the fired structure has a ceramic and an organic fiber as main components, and the honeycomb ceramic structure according to any one of the first to twelfth means. (Claim 13). The organic fibers are burnt out during firing to form a predetermined porosity according to the type and form of the organic fibers and the firing conditions (temperature, atmosphere).

A fourteenth preferable means is the honeycomb-shaped ceramic structure according to any one of the first to thirteenth means, characterized in that it is fired from a ceramic raw material and a raw material containing an inorganic fiber as a main component. (Claim 14).

The fifteenth preferable means is any one of the first to fourteenth means characterized in that the outer peripheral surface of the honeycomb-shaped ceramic structure is wrapped with a sheet-like body or tubular body made of metal. The honeycomb-shaped ceramic structure according to (15). The sheet-like body or the tubular body is, for example, a metal plate around a thin film (sheet-like body) having a thickness of not more than a micrometer formed by plating, etc. Up to a sheet-like body or a tubular body formed to a thickness of. Furthermore, the case where the honeycomb ceramic structure is fitted and housed in a metallic tubular body (cylindrical body) is included. Further, the tubular body made of metal may have a honeycomb structure. As the metal material forming the film or the tubular body, a material having heat resistance and corrosion resistance such as stainless steel is preferable.

[0034]

The first feature of the honeycomb-shaped ceramic structure of the present invention is that it comprises a plurality of honeycomb-shaped ceramic modules. Ceramics have excellent characteristics such as high hardness and high melting point, but on the other hand, they are brittle materials, and in the case of thermal shock (abrupt temperature change or thermal gradient), special materials and manufacturing methods must be used. For example, it was difficult to use ceramics.

For example, a catalyst carrier for automobile exhaust gas is
Cordierite, which has a very small coefficient of thermal expansion in a specific direction of the crystal, is extruded into a product by orienting the crystal direction in one direction.

However, even with such a catalyst carrier, there is a limit to the size increase of the carrier and the thinning of the cell wall (improvement of the cell degree) due to problems such as thermal shock due to the temperature difference between the exhaust gas inlet and the outlet, which is sufficient. It was not possible to obtain good mechanical strength. Also, from the viewpoint of the manufacturing process (extrusion molding, etc.), if the size is increased (particularly, the structure is elongated in the cell axial direction), the flowability and crystal orientation of the molding material deteriorate, and the cell thickness is reduced It was difficult to put the cell into practical use because it also deteriorates the fluidity of the molding material and causes breakage and deformation of the cell frame during demolding.

Furthermore, the initial investment for equipment such as an extruder is extremely large.

However, in order to improve the catalyst efficiency and performance, it becomes necessary to increase the surface area of the catalyst carrier by increasing the size of the catalyst carrier or reducing the cell thickness. In addition, in recent years, exhaust emission regulations for automobiles have become even more stringent to prevent pollution. In 1990 and 2004, regulations on nitrogen oxides in small and medium-sized diesel vehicles were tightened, and in 1994 and 2007, diesel weights were reduced. Restrictions on nitrogen oxides will be tightened for cars, medium-weight and heavy-duty gasoline trucks and buses. All of these vehicle types have large displacements, and in order to meet such regulations, development of excellent catalyst carriers has become an urgent task.

The honeycomb-shaped ceramic structure of the present invention comprises:
It is suitable as a catalyst carrier for automobiles, which can be made large and the cell thickness can be made thin, and which contributes to pollution control in response to the above strict regulations on exhaust gas.

That is, a honeycomb-shaped ceramic structure having a structure that absorbs thermal shock by being laminated in the axial direction of the open-cells and composed of the honeycomb-shaped ceramic modules having a predetermined thickness.

Since the structure is not integrated but is made up of a plurality of modules, the cell axial distance of each module is shortened, and the temperature difference between the inflow port and the outflow port in the exhaust gas flow direction in each module is shortened. , The thermal shock of the individual modules is reduced. Also, the thermal shock in the radial direction of the open cell (cross-sectional direction) is reduced.

Such a honeycomb-shaped ceramic structure composed of modules having a large major axis in the transverse direction of the open cells and being thin in the axial direction of the open cells is integrally formed as in the conventional case and has the same outer shape (open hole). Compared to a structure having a large major axis in the transverse direction of the cell and being thick in the axial direction of the open cell), the temperature difference (thermal shock degree) between the modules is small, and there is almost no possibility of cracking due to strain due to thermal shock.

Further, by integrally molding and sintering a structure having a large major axis and a large thickness, it is possible to form cracks, cracks, etc. due to the small structural retention force at the time of molding and shrinkage strain at the time of sintering.
Since poor sintering occurred, the yield was lowered and it could not be put to practical use.

However, the structure composed of the module of the present invention can be manufactured in an arbitrary size according to the purpose of use and the application (especially, the thickness in the cell axial direction can be arbitrarily selected). It is a structure that does not cause manufacturing defects during molding or sintering and is resistant to thermal shock during use.

In particular, in the case of a structure having a large diameter and a large thickness as a whole, if the module structure is used, it is effective that the above manufacturing defects do not occur and that it is resistant to thermal shock during use.

The honeycomb-shaped ceramic structure of the present invention preferably has a plate-shaped or disk-shaped structure, but preferably has a major axis L in the transverse direction of the open cells of the honeycomb-shaped ceramic module of 10 cm or more. Or a honeycomb ceramic structure in which the axial thickness T of the open cells is 0.3 to 1 cm, or the thickness / major axis ratio T / L is 0.5 or less. The structure composed of such a module exhibits the effects of not causing the above-mentioned manufacturing defects during molding or sintering and being resistant to thermal shock during use.

Further, one of preferred modes of the module forming the structure is that the major axis L in the transverse direction of the open cells of the honeycomb-shaped ceramic module is 10 cm or more, the axial thickness T of the open cells is 1 mm or more, and the thickness is 1 mm or more. It is a honeycomb-shaped ceramic structure having a T / L of the major axis ratio of 0.5 or less.

Further, as one of the more preferable forms of the module forming the structure, T / L of the thickness / major axis ratio of the honeycomb-shaped ceramic module is 1/10 or less, further preferably T / L is 1/50 to 1. It is a honeycomb-shaped ceramic structure having a ratio of / 100 or less.

By laminating a large number of such relatively thin modules, it is possible to form a structure having a size that could not be realized conventionally due to defective molding and firing. Further, by stacking a large number of modules having different types and various functions / forms, various functions can be exerted in one structure.

Further, in the present invention, the thermal expansion can be absorbed at the joint portion between the modules. That is, for example, the modules can be joined by providing a cushioning material on the joining surface between the modules.

Second, in a structure composed of a plurality of modules, a cushioning material is provided between the modules or / and at both ends of the structure. For example, in the case of a catalyst carrier for automobile exhaust gas, exhaust gas is discharged from the exhaust manifold of the engine. The can is made into the exhaust pipe between the outlet pipes.

As described above, since the structure made up of modules has a very high degree of thermal shock absorption, conventionally, a cordierite matrix having a very small thermal expansion was coated with alumina having a large surface area. According to the present invention, it is possible to use a material having a relatively large thermal expansion coefficient (8 × 10 ⁻⁶ / ° C.) such as alumina itself. Alumina also has the advantage of high strength, and thus the applicability of ceramic raw materials having various excellent properties to a honeycomb-shaped ceramic structure can be expanded by the present invention.

The modules are stacked so that the cells penetrate (communicate) in the axial direction. The communication hole of the cell penetrating therethrough need not be linear or / and the cell wall defining the hole is continuous. Curved or spiral, stepped or zigzag structures, or fluid splitting
A structure that performs re-merging and repeats is preferable because it can increase the chance of contact with gas during ventilation, and even if the cell wall is intermittent, the fluid passing through the cell becomes a substantially helical flow, A structure in which the pressure loss of the structure is reduced is also preferable, and it is a great advantage of modularizing the structure of the present invention that these can be freely selected.

According to the present invention, the spiral communication holes can be easily formed by rotating each module little by little about the axis (changing the angle) or alternately joining the modules.

Further, a step-like communication hole can be formed by changing the cell wall width little by little, or even in a module having the same cell cross-sectional shape, by shifting the modules and combining them.

Furthermore, as an advantage of modularization, different functions can be given to each module in the axial direction. For example, it is possible to combine each module that carries an optimum catalyst for adsorption of fine particles, HC, CO, NO _{X, and the} like. Conventionally, since it is an integral type, it is difficult to provide different coating layers inside the cell after molding, and a structure for binding cell tubes having different functions in the cell cross-sectional direction is also conceivable, but with this structure, Since each cell acts (absorbs or adsorbs) only one kind of target in the axial direction, the performance is very poor.

As a result, it is possible to replace only the module for adsorbing fine particles, which is particularly likely to be clogged during replacement.

The honeycomb-shaped ceramic structure of the present invention is
Due to the above characteristics, it can be used as a catalyst carrier for automobile exhaust gas, not only for gasoline engines but also for diesel engines and large-sized engines. further,
Typical applications other than the catalyst carrier for automobile exhaust gas include catalyst carriers for various chemical reactions, bioreactors, exhaust gas treatment devices for factories and power plants, water purifiers, waste water purification devices, etc. The use of the structure is not limited to these.

[0059]

【Example】

<Example 1> An outline of an example of the structure of the honeycomb-shaped ceramic structure 1 of the present invention will be described with reference to FIG.
(A) is a perspective transparent view of a honeycomb-shaped ceramic structure 1, (b) is a perspective transparent view of a disk-shaped honeycomb-shaped ceramic module, (c) is a cross-sectional view taken along the line cc 'of (a). The open cell 3 and the cell wall 4 are shown in particular.

That is, there are many open cells 3 partitioned by the cell wall 4 (FIG. 1 (c)). Honeycomb-like ceramic module 2 having open cells 3 having such a cross-sectional shape (see FIG.
(B)) is laminated in plurality (five in the figure) (FIG. 1).
(A)). In addition, the open cells 3 of the modules 2 are stacked so as to communicate with each other.

Example 2 Several methods of manufacturing the honeycomb-shaped ceramic module 2 of the present invention will be described. However, the module of the present invention is not limited to the manufacturing method described in this embodiment.

One is extrusion molding. This is a method of obtaining a honeycomb-shaped molded body by extruding a mixture (kneaded clay) to which ceramic powder and a binder have been added and kneaded through a molding die corresponding to the cross-sectional shape of an open cell. The molding die is
It is composed of a cylindrical feeding portion for feeding the kneaded material and a matrix-shaped slit forming a molded body (cell) portion. The conventional catalyst carrier for automobile exhaust gas is produced by crystallizing cordierite by this extrusion method (not shown).

Table 1 shows an example of the relationship between the composition (weight ratio) of the cordierite substrate and the firing temperature. These raw materials and the like are also used in other manufacturing methods.

[0064]

[Table 1]

Next, Table 2 shows an example of the relationship between the type and weight ratio of the ceramic raw material and the binder. These raw materials and the like are also used in other manufacturing methods.

[0066]

[Table 2]

When Wollastonite is used by substituting or mixing with these ceramic raw materials, mechanical strength and impact strength can be increased, and it is more preferable that Wollastonite is 5 to 60 wt%. .

The second is the calendering (corrugation) method. A kneaded material whose plasticity is adjusted by a molding aid is corrugated or embossed to form a corrugated or uneven sheet, and a single sheet or a flat sheet is wound (lens) and wound in concentric circles to form a honeycomb structure. (Not shown).

The third is a pipe binding method as shown in the schematic process diagram of FIG. A tubular body 22 is formed by extrusion molding, or a flexible ceramic material sheet is rolled into the tubular body 22, and a plurality of the tubular bodies are combined and wrapped with a flat ceramic material sheet 24 to open a hole. The honeycomb ceramic module 2 is formed by cutting along the cell cross section and firing. The structure of the honeycomb ceramic module 2 can be directly obtained without the cutting.

The fourth step includes the step of laminating the ceramic material perforated sheet 30 as shown in the schematic process diagram of FIG. 2 (b). That is, it is a method of obtaining a honeycomb structure having open cells by making a large number of holes in a bulk material (plate-like body) or material sheet made of kneaded clay by a press or the like. Drilling
Alternatively, laser processing may be used. It should be noted that a relatively thick sheet-like body (block body, plate-like body) can be perforated at once, or a relatively thin sheet-like body (ceramic paper, etc.) can be perforated, or it can be pre-perforated. A honeycomb-shaped structure can be obtained by producing an open sheet-like body by papermaking, stacking the perforated sheets, and firing.

As a particularly preferable manufacturing method, there is a method of manufacturing a ceramic material sheet from a mixture (kneaded clay or the like) composed of a ceramic raw material and organic fibers, and manufacturing a honeycomb structure using the ceramic material sheet as a material.

For example, in addition to the roll method as shown in FIG. 2C, a kneaded clay containing ceramics or a mixture containing ceramics and a binder is formed into a sheet by an ordinary wet papermaking method, doctor blade method, or pressing method. You can

In the roll method as shown in FIG. 2C, the ceramic / binder mixture 20 and the organic sheet 21 are compressed by a pressure roll 25 to form a sheet, and further dried by a heating roll 26. Thus, the ceramic material sheet 24 can be manufactured.

It is also possible to obtain a honeycomb structure having open cells by subjecting the mixture of the organic fiber and the ceramic raw material to a bulk by a wet or dry press and press-cutting as a thick sheet-shaped body (block-shaped body). Illustration is omitted).

The ceramic material sheet obtained by such a method is excellent in flexibility and shape-retaining power, and is one of the methods for manufacturing the honeycomb-shaped ceramic module of the present invention. It is a ceramic sheet suitable as a raw material to be used.

Table 3 shows an example of the type and weight ratio of the ceramic raw material and the organic fiber. If alumina is contained, a structure having particularly high strength can be manufactured. These are raw materials for manufacturing various ceramic material sheets and ceramic structures.

[0077]

[Table 3]

Here, as in the case of Table 2, if Wollastonite is used by substituting or mixing with these ceramic raw materials in Table 3, mechanical strength and impact strength can be increased, which is preferable. , And more preferably 5 to 6
It is 0 wt% wollastonite.

The honeycomb structure manufactured from the organic fibers and the ceramic raw material is excellent in flexibility and shape retention due to the supporting force of the organic fibers for the ceramic particles (powder) when forming the honeycomb structure before firing. Therefore, it is particularly suitable for manufacturing a honeycomb structure having a complicated cell shape.

Further, after firing, the organic fibers are burned off and the ceramic matrix becomes porous, and the surface area increases, which is particularly preferable as a catalyst carrier.

The honeycomb-shaped ceramic structure manufactured by the above method is fired to form a porous sintered body. The firing temperature depends on the material and application. For example,
The various firing conditions for cordierite are as already shown in Table 1.

Table 4 shows an example of ceramic raw materials and binders (including organic fibers) which are raw materials used in the above-mentioned manufacturing method for the honeycomb-shaped ceramic module (structure).

[0083]

[Table 4]

Table 5 shows an example of the new ceramic raw material. This new ceramic can also be a material of the module (structure) according to the present invention. Also, although organic fibers were used as a part of the raw material of the ceramic material sheet,
Inorganic fibers also serve as a raw material for the structure of the present invention, and can be used as a raw material alone or as a mixture with organic fibers. In particular, the use of inorganic fibers (ceramic fibers) is preferable because it does not burn off during firing and strengthens the toughness of the module (structure).

[0085]

[Table 5]

The raw materials for the ceramic material sheets exemplified in Tables 4 and 5 (kneaded clay, binder (organic fibers, etc.))
The so-called new ceramic raw materials (kneaded clay, ceramic fibers, etc.) are prepared in various compositions according to the purpose and application.

Further, the honeycomb-shaped ceramic module (structure) may be coated (sprayed, coated, dipped, etc.) with slurry containing a ceramic component before firing. Thereby, the porosity and the specific surface area can be adjusted. Further, after firing, it may be covered with the slurry and further fired, so that the strength is relatively increased. In particular, if it is coated with a slurry containing an alumina component and baked, it will have high strength.

Example 3 A method for manufacturing the honeycomb-shaped ceramic structure 1 by stacking a plurality of honeycomb-shaped ceramic modules 2 so that the open cells 3 of the honeycomb-shaped ceramic modules 2 communicate with each other will be described. In this embodiment, the module 2
The shape of is a disk-shaped body (plate-shaped body) having a circular cross section.
However, it is not limited to this. The cross-sectional shape includes a polygon such as a quadrangle, a pentagon, and a hexagon, an ellipse, a semicircle, a substantially circle such as a fan, and an irregular shape.

There are various conceivable ways of joining the modules. One is a mechanical assembly (fitted in an outer cylinder and absorbs thermal expansion and vibration through an elastic material as necessary.

Secondly, the outer peripheral portion of the module 2 is welded for each module, or only a part thereof is welded to the outer cylinder, and the unwelded module 2 is sandwiched or fitted by another brazed module or outer cylinder. To be dressed.

Thirdly, a paste such as silicon oxide, yttrium oxide, or titanium oxide, which is a sintering aid, is applied to the surface of the cell opening portion of the cell frame 4 of each module, and both modules are joined. .

It is also preferable to sandwich a thermal stress absorbing insert material between the modules as a joining member. For example,
Fe-Ni-Cr, Kovar and the like.

The fourth method is a method of inserting a rod-shaped body (cylindrical body) that penetrates and holds each module into at least one of the open cells 3 communicating with each other.

The fifth is a method of mechanically joining the tenons by providing tenons that fit with each other. Such tenons can easily be provided in the pre-sintering (plasticizing) stage of the module. In addition, you may use together the said joining member as an auxiliary material.

In FIG. 1, modules 2 having the same length (in the axial direction of the open cell), the same diameter, and the same open cell are stacked, but modules having different lengths, diameters, and open cells are stacked. You may laminate. Alternatively, hollow donut-shaped modules may be stacked.

<Embodiment 4> The three-dimensional structure of the open cells 3 communicating with each other will be described. In FIG. 1, a similar module 2
Since the cells are laminated coaxially and at the same angle, the aperture cells are formed linearly (square columnar shape) in the axial direction of the aperture cells.

FIG. 3 is a perspective partial cross-sectional view of the honeycomb-shaped ceramic structure 1, where (a) is stepped (stepped open cells 7) and (b) is helical (helical open cells 8). The three-dimensional structure of the open cell 3 formed in FIG.

In (a), the step in the adjacent module is enlarged and exaggerated for convenience of drawing. However, when the cell wall is thin as shown in the drawing, one cell of another module is adjacent to the adjacent module. Will be conducted to a plurality of cells.

In this way, the three-dimensional structure of the open cell 3 can be formed in a substantially spiral shape (stepwise 7 or spiral open cell 8). According to the method, when the honeycomb-shaped ceramic modules 2 having the same shape (outer diameter, open-cell shape) are combined in the spiral-shaped open cell 8, the center is rotated coaxially little by little (in both forward and reverse directions). Therefore, with the outer diameters matched, the inner open-cells 3 rotate and communicate in a spiral shape. For this reason, the volume of the entire structure 1 does not change, and the surface area or the contactability of the passing fluid is increased, and, for example, in the case of a catalyst carrier, the reaction efficiency with respect to a certain volume of the passing fluid is increased. If the fluid rotates spirally,
As a result, turbulence occurs in the flow, and the passing flow in the cell has a higher contact efficiency with the cell wall than the parallel linear flow.

Further, in the open cells 7 having a staircase-like or staggered angular offset arrangement, the modules 2 are stacked so that the open cells 3 are slightly shifted, and the open cells communicating in a stepwise manner as shown in FIG. Pore cells 7 can be formed.

The step-like structure is a method for increasing the surface area, which is suitable for the honeycomb-shaped ceramic module 2 having a rectangular cross section. The spiral open cell 8 is particularly suitable for the module 2 having a cylindrical outer shape.

FIG. 4 schematically shows the cell walls 4 of the plate-shaped modules 2 stacked in the honeycomb-shaped ceramic structure 1 with the phases of the open cells shifted, and FIG. It is a top view, (b) is a side view, and the arrow has shown typically a part of fluid flow. First-stage cell wall 4
All of a are shown by solid lines, and the cell wall 4b of the second module is shown.
Is cut at a point that intersects with 4a three-dimensionally (a point that appears to overlap) for convenience of illustration. It should be noted that P1 and P2 respectively represent the opening cell pitches of the first and second stages.

FIG. 5 is a plan view of the cell open surface of the honeycomb-shaped ceramic structure 1, showing a part of the cell walls of the disk-disk-shaped modules laminated with the open cells 4 shifted in phase. (A) is a module in which the cross-sectional shapes of the open cells are different, and (b) is a module in which the cross-sectional shapes of the open cells are the same. The cell walls 4a in the first stage are all indicated by solid lines, and the cell walls 4b in the modules in the second stage are indicated by dotted lines. The opening cell pitch in the 1st and 2nd steps is radial,
They are offset by half a pitch in the circumferential direction. Note that reference numeral 5
Is a structure (module) outer wall, and reference numeral 6 is a structure (module) core. The core 6 has a structure in which the temperature and the uniformity of components of the fluid passing through the open cell in the cross-sectional direction are increased.

As in the honeycomb-shaped ceramic structure 1 shown in FIGS. 4 and 5, if the cells are stacked by shifting the open-cells by half pitch in the vertical and horizontal directions or in the radial and circumferential directions, the open-cells in the first-stage module are The fluid that has passed through the central portion comes into contact with the lattice points of the cell wall in the second stage (the same applies to the third and fourth stages), increasing the chances of contact of the fluid with the cell wall 4, and in addition, as shown in FIG. ), The pressure loss of the fluid is small because the cross-sectional area of the fluid passage for each module does not change.

As described above, even if the fluid passages, that is, the cell walls surrounding the communicating open cells are not continuous but intermittent, the fluid passing through the open cells can be made into a substantially helical flow.

Further, the fluids that have passed through the outer peripheral portion and the central portion of the module are mixed, and the temperature and the components are made uniform. Such a structure is suitable for a chemical reaction device such as a catalyst carrier, especially for a catalyst carrier for removing exhaust gas.

By rotating a module having the same cross-sectional shape of the open cell as shown in FIG. 5B around the center of the cross section, a substantially spiral fluid passage is formed from the same module. be able to. However, the module length, the material, and the like in the axial direction of the open cell may be different.

By the way, the cell wall (frame) 4 is not easily damaged by its own weight because it is manufactured for each module (for each small portion). Further, even during sintering, breakage due to uneven thermal expansion is unlikely to occur. For example, in extrusion molding,
Cell wall thickness is 0.2 mmt (up to about 0.1 to 0.3 mmt is possible) and open cell angle is 1.2 mm □. The surface area of is increased in total.

<Embodiment 5> In particular, when the honeycomb-shaped ceramic structure 1 is used as a catalyst carrier, an alumina coating (γ-alumina) is applied to the inner wall of the open cell 3 in order to improve the specific surface area and the catalyst carrying ability. Etc.)

Alumina coating layer (overcoat)
Is carried out by baking at a predetermined temperature after sludge coating (immersion, spraying, etc.), and the supported catalyst can be attached by forming a catalyst layer or encapsulating or adsorbing on a coating layer such as alumina itself. As an example, the catalyst layer (noble metal, base metal, etc.) is formed on the base material of the honeycomb-shaped ceramic structure 1 or preferably on the alumina coating layer by CVD, the active metal method, or solid phase (or liquid phase) diffusion bonding.

In particular, as a material for increasing the surface area and increasing the chemical reaction efficiency, a catalyst 10 is supported by forming a γ-alumina coating layer on the honeycomb ceramic structure base material. Let In many cases, the catalyst 10 does not form an independent layer of the catalyst, but penetrates the particle gaps of the porous alumina coating layer and forms the surface layer of the alumina layer.

<Embodiment 6> In this embodiment, a honeycomb-shaped ceramic structure 1 having a different function for each module 2 and carrying a catalyst will be described.

Table 6 shows examples of the noble metal type catalysts, their uses, and supports.

[0114]

[Table 6]

Table 7 shows an example of the type, application and carrier of the base metal catalyst.

[0116]

[Table 7]

As a multifunctional catalyst, a rare earth element is R,
When the transition element is T (Mn, Fe, etc.) and the alkaline earth metal is D (Mg, Ca, Sr, Ba, etc.), R _1-X D _X T
A catalyst having a composition of O ₃ is also preferable because it does not use an expensive precious metal element. The range of x = 0.1 to 0.6 is preferable, and the range of x = 0.5 is more preferable.

[0118] Further, as a catalyst for effectively removing NOx, Cu ₂ obtained by firing in an N ₂ or CO atmosphere Cu ⁺ zeolite (e.g. ZSM-type) doped to a firing temperature of about 800 to 1000 ° C. It is also preferred to use an O catalyst. However, since ZSM type zeolite is expensive, it is also preferable to use other natural mordenite as the zeolite.

As an example in which catalysts having different functions as described above are carried in FIG. 6, a particulate filter suitable for use as a catalyst carrier for automobile exhaust gas (particularly for diesel) is particularly preferable. (PF) module 2a, heating element module 2b, catalyst supporting module 2
The exploded view of the honeycomb-shaped ceramic structure 1 which consists of c etc. is shown.

The module 2a is a module which is a particulate matter filter. The material is preferably an alumina substrate (γ-alumina or the like), zeolite (for example, tectoaluminosilicate), or the like, and may be a cordierite substrate. Alternatively, a mixed base material may be used in which these are mixed to increase the advantages of both base materials. In this module, in particular, solid carbide fine particles are adsorbed and removed.

The module 2b is a heating element module, and is a honeycomb ceramic structure made of TiC or B ₄ C, SiC, MoSi. Further, a honeycomb structure made of a metal or an alloy having high resistance and high heat resistance may be used. This module generates heat when energized to ensure catalyst performance after starting and under high load.
The fine particles adsorbed in a can be removed by burning. It is also preferable that this module is a metal module containing molybdenum as a main component.

The module 2c is an oxidation catalyst carrier,
An example is a Pt-Pd catalyst. CO, HC, etc. are oxidized to make them harmless and removed as CO ₂ or H ₂ O.

The module 2d is a reduction catalyst carrier,
An example is a Mn-Ce based catalyst. Reduce NO,
It is rendered harmless as N ₂ . Also, as an example of this, Ru
A system may be used.

The module 2e is a three-way catalyst carrier,
One example is a Pt-Rh-based catalyst. CO, HC, etc. are oxidized to CO ₂ or H ₂ O, and NO _x is reduced to N ₂
To make it harmless.

The modules 2d and 2e are further used as the above-mentioned or other modules if necessary. In the above case, it goes without saying that the modules 2a, 2b, and 2c are used by stacking an arbitrary number of modules. The order of arrangement can be changed as necessary.

Since each module 2 can be designed by changing the arrangement location depending on the operating temperature and relative position of each catalyst to be carried, the catalyst efficiency as a whole is greatly improved.

The properties of the fine carbide particles (weight, density,
Depending on the (specific surface area), the cell opening 3 shape, the cell cross-sectional shape,
By varying the cell diameter and the porosity of the ceramic body, it is possible to collect all the various types of carbide fine particles.

<Embodiment 7> FIG. 7 shows a cross-sectional view of the honeycomb-shaped ceramic module 2 according to an embodiment of the present invention, showing the module length L in the cross-sectional direction of the open cells 3 and the axial direction of the open cells. In particular, the module thickness T of is shown.

As shown in the figure, it is preferable for the structure of the present invention that a relatively flat plate-shaped or disk-shaped module is laminated. This is because the thickness T in the axial direction of the open cell is particularly small, so that the temperature difference in this direction is small and the thermal strain is also small. In addition, when T is thin, it is easy to manufacture, and the large-diameter (L) module 2 can be easily manufactured. Specifically, it is possible to manufacture a honeycomb-shaped ceramic module having a long diameter L in the transverse direction of the open cells of 10 cm or more, and by stacking these, a large-sized structure can be manufactured. When L is 10 cm or more, the honeycomb-shaped ceramic structure of the present invention is suitable for a field requiring a large-sized exhaust gas catalyst carrier such as a diesel vehicle.

Further, for manufacturing reasons, it is preferable that the axial thickness T of the open cells is 1 mm or more, so that cracks and the like of the cell wall 4 are reduced and the yield is improved.

Expressed in terms of the module thickness / major axis ratio (T / L), T / L is more preferably 0.5 or less, and further preferably T / L is 0.25 or less. . By stacking modules having such a T / L relationship, a structure having an arbitrary size can be obtained without causing defects such as cracks and cracks during the manufacturing process (especially during honeycomb forming and sintering). It is possible to prevent thermal damage during use by absorbing the shock for each module, and also to prevent mechanical shock between modules, or shock (thermal / mechanical) An absorption layer (material) can be provided between the modules, and the shock absorption capacity is further improved. It is preferable to mix the inorganic fibers as a raw material for the module (structure) because the mechanical strength, toughness and impact resistance as well as thermal shock are improved.

Then, T / L is 0.5 or less, and further 0.
When it is 25 or less, the thermal / mechanical shock absorption capacity is improved, and as the T / L is smaller, a large number of modules can be stacked if the structure has the same length in the axial direction of the open cell. , Each module can be provided with many different functions, or can be provided with a tilt function. Also, the degree of freedom in designing the cell communication shape is increased.

<Embodiment 8> An example of the structure in which the honeycomb-shaped ceramic structure of the present invention is actually used as a catalyst carrier in an automobile engine system will be described.

A honeycomb ceramic structure is fitted as a catalyst carrier into an exhaust pipe (exhaust pipe) connecting the exhaust gas discharge pipe and the engine.

For applications other than those related to automobiles, any large product can be easily produced by lamination and has thermal shock resistance, so that it can be used for diesel engine gas catalyst for power generation, catalytic reactor of chemical plant. Is suitable. It can also be used in bioreactors and the like. Further, since different catalyst functions can be given to each module, it is also suitable for a multi-stage reaction device (multi-stage catalyst device).

<Example 9>

The honeycomb-shaped structure of the present invention can be combined with a metal material to form a ceramic-metal composite structure. For example, strength and toughness can be improved by forming the outer peripheral portion (face) of the honeycomb-shaped ceramic structure with a metal plate-shaped body made of stainless steel as a wrapped tubular body. The strength and toughness can also be improved by welding a metal to the outer peripheral surface by plating or the like to form a sheet-shaped body.

Further, the strength and toughness can be improved by the structure in which the honeycomb ceramic structure is housed in the metal pipe (tubular body or tubular body) of stainless steel or the like. Alternatively, a honeycomb-shaped metal structure having cells may be provided on the outer peripheral portion (surface) of the honeycomb-shaped ceramic structure to further improve the shock absorption.

[0139]

Since the honeycomb-shaped ceramic structure of the present invention is composed of a plurality of modules, it is possible to increase the size by stacking the modules (claim 1).
And 2). Further, since each module is sintered, it is possible to easily realize a thin cell wall and a complicated cell shape.

In addition, when the distance in the axial direction of the open cell of each module is shortened and there is a heat flow or a temperature difference at both ends of the structure, the temperature difference between the inflow port and the outflow port is reduced for each module. The thermal shock of the individual modules is reduced, and the structure as a whole can provide a structure that is very resistant to thermal shock.
Further, the thermal expansion can be absorbed at the joint portion between the modules.

Further, by manufacturing each module, a honeycomb-shaped ceramic structure in which molding defects, defects such as cracks and cracks are reduced at the time of honeycomb molding and firing, that is, the yield at the time of manufacturing can be improved. Can be provided.

Since each module can be replaced, even if a certain module is damaged or clogged,
Only that module can be replaced.

From the above, since it is resistant to mechanical stress and thermal shock and has the above-mentioned advantages during the manufacturing process, a large-sized cell having an outer diameter in the cross-sectional direction of the open cells of the honeycomb-shaped ceramic structure is 10 cm or more. A honeycomb ceramic structure is obtained. With respect to the outer diameter, a preferable molding method other than the extrusion molding method can be used, and in particular, if it is molded from a sheet-shaped body containing organic fibers, it is possible to have a size of 30 cm or more to 50 cm, and in some cases even 1 m or more. . Also,
The axial dimension of the open cell can be virtually infinitely long (claim 1).

The form of the module is relatively thin like a plate or a disk, and has the advantage particularly in the above manufacturing process, and the form of a module having various forms and functions is one structure. It can be included (claim 2).

Specifically, in terms of the thickness / major axis ratio (T / L) of the module, L is 10 cm or more and T / L is 0.5 or less, so that a structure having an arbitrary size can be obtained. It can be obtained without cracks, cracks, and other defects during the manufacturing process (especially during honeycomb molding and sintering), and thermal shock during use can be prevented by absorbing the shock of each module. And can absorb mechanical shock between modules, or shock (thermal / mechanical)
An absorption layer (material) can be provided between the modules, and the shock absorption capacity is further improved. In addition, as the T / L is smaller, for example, if the structure has the same length in the axial direction of the open cell, a large number of modules can be stacked, so that each module has many different functions or has a tilt function. be able to. Also, the degree of freedom in designing the cell communication shape is increased. As described above, since a honeycomb-shaped ceramic structure having a large diameter (L) and an arbitrary size (T direction) can be easily obtained, the exhaust gas of a diesel engine for a diesel vehicle, a power generator, or a marine diesel engine is particularly useful as a large catalyst carrier. It is excellent as a catalyst carrier (claim 3).

Different module shapes for each module,
For example, in the outer diameter, length, and open cells, the cell degree, cell wall thickness, number of cells, cell three-dimensional structure (tapered shape, etc.), material, etc. can be changed, and different types of structure can be obtained. A variety of functions can be exhibited (Claim 4).

Each module is laminated so that the cells penetrate (communicate) in the axial direction, and the communication holes of the penetrated cells should be formed in a zigzag shape or a curved shape (helix shape, step shape). You can With this, for example, in the case of a catalyst device, it is possible to increase the contact property between the fluid passing through the cell and the catalyst carried on the cell wall, and it is excellent as a chemical reaction device, for example, a catalyst carrier. 8).

Specifically, the substantially spiral communication holes can be easily formed by coaxially rotating or staggering the modules having the same cross section of the open cell and having a circular cross section, and the mass productivity is high. Item 6).

If the modules are joined by forming a shock absorbing member (cushioning material) on the joint surface between the modules or on both ends of the structure, a honeycomb ceramic which is strong against mechanical stress (tensile, compression) and thermal stress. It becomes a structure (Claim 7).

Further, since it has a honeycomb structure, it has a large specific surface area and has a module structure that is resistant to thermal shock.
The structure of the present invention is suitable as a catalytic reactor (claim 8).

Furthermore, as an advantage of modularization, different functions can be given to each module in the axial direction. For example, it is possible to combine each module carrying an optimum catalyst for adsorption of fine particles, HC, CO, NO _X, etc., and to perform a composite function in one structure. Such a structure is extremely excellent as a catalyst carrier for automobile exhaust gas, which requires thermal shock, mechanical stress, and catalytic action of different types (claims 9, 10 and 1).
1).

Furthermore, by combining modules made of ceramics, it is possible to change the particle size, density, etc. adsorbed by the modules when different functions, for example, in the case of a dust-exhausting device, and especially when both ends of the structure have high strength. A module made of a ceramic material can be used, and a structure having a tilt function in the axial direction of the open cell can be obtained (claim 12).

By firing the organic fiber as a raw material to sinter the structure, the organic fiber is burned off at the time of sintering, so that pores on the order of micrometer, which are larger than the fine pores on the order of angstrom on the ceramic material, are formed. A porous body having a porous body can be manufactured, the surface area is increased, and it is suitable for an automobile exhaust gas purifying apparatus, and can withstand a high load such as a diesel engine. Further, for example, also in a chemical reaction device, the reaction area can be expanded and the reaction efficiency is improved (claim 13).

A honeycomb ceramic structure fired from a ceramic raw material and a raw material containing inorganic fibers as main components is
The inorganic fibers are not burned off even after firing, and the strength of supporting the ceramic material by the fibers is strong, so that the strength and toughness of the structure are improved (claim 14).

The honeycomb-shaped ceramic structure in which the outer peripheral surface of the honeycomb-shaped ceramic structure is wrapped with a sheet-shaped body or tubular body made of metal can improve strength and toughness (claim 15).

The applications other than the catalyst carrier for automobile exhaust gas include catalyst carriers for chemical reaction / decomposition, bioreactors, water purifiers, waste water purification devices, exhaust gas treatment devices for factories, power plants, ships and the like. It is not limited and has wider applications.

[Brief description of drawings]

1A and 1B show a honeycomb-shaped ceramic structure 1 according to an embodiment of the present invention, in which FIG. 1A is a perspective transparent view of a honeycomb-shaped ceramic structure 1, and FIG. 1B is a perspective transparent view of a honeycomb-shaped ceramic module. , (C) are cross-sectional views of (a) taken along the line cc ', particularly showing the open cell 3.

FIG. 2 shows a method for manufacturing a honeycomb-shaped ceramic structure and a ceramic material sheet which is a raw material thereof.
(A) is a method for manufacturing a honeycomb-shaped ceramic structure by a pipe binding method, (b) is a method for manufacturing a honeycomb-shaped ceramic structure by a press die cutting method, and (c) is a ceramic material sheet by a roll forming method. Is a manufacturing method.

[Fig. 3] Fig. 3 is a perspective partial cross-sectional view of a honeycomb-shaped ceramic structure 1, in which (a) shows a three-dimensional structure of open cells 3 formed in a staircase, and (b) shows a spiral. The three-dimensional structure of the open cell 3 formed in the shape of FIG.

[Fig. 4] Fig. 4 schematically shows cell walls 4 of plate-shaped modules 2 that are stacked by shifting the phase of open cells in a honeycomb-shaped ceramic structure 1, and (a) is a cell open surface. 2B is a plan view, FIG. 3B is a side view, and arrows schematically show part of the fluid flow.

[Fig. 5] Fig. 5 is a plan view of cell open surfaces of the honeycomb-shaped ceramic structure 1, showing a part of cell walls of disk-disk-shaped modules in which the open cells 4 are stacked out of phase. , (A) is a module having different cross-sectional shapes of open cells,
(B) is a stack of modules having the same cross-sectional shape of the open cell. The first-stage cell walls 4a all show a part of the cell walls of the disk-disk-shaped modules that are stacked by shifting the phase of the actual open-hole cells 4. The cell walls 4a in the first stage are all indicated by solid lines, and the cell walls 4b in the modules in the second stage are indicated by dotted lines.

FIG. 6 shows particulates as an example of stacking catalyst-supporting catalysts having different functions on a honeycomb-shaped ceramic module 2 which is an embodiment of the present invention.
Filter (PF) module 2a, heating element module 2
FIG. 3 shows an exploded view of a honeycomb-shaped ceramic structure 1 including b, catalyst supporting modules 2c, 2d, and 2e.

FIG. 7 is a cross-sectional view of the honeycomb-shaped ceramic module 2 which is an embodiment of the present invention, showing the open cell 3
In particular, the module length L in the cross-sectional direction and the module thickness T in the axial direction of the open cell are shown.

[Explanation of symbols]

 1 Honeycomb Ceramic Structure 2 Honeycomb Ceramic Module 3 Open Cell 4 Cell Wall (Cell Frame)

Claims (15)

[Claims] 1. A plurality of honeycomb-shaped ceramic modules each having a predetermined thickness and having a predetermined thickness are laminated in the axial direction of the open cells so that the axial directions of the open cells communicate with each other, and the honeycomb shape having a predetermined thickness is formed. A honeycomb-shaped ceramic structure formed by arranging a plurality of ceramic modules. 2. The honeycomb-shaped ceramic module,
The honeycomb ceramic structure according to claim 1, wherein the honeycomb ceramic structure has a plate shape or a disk shape. 3. The major axis L of the open cell of the honeycomb ceramic module in the transverse direction is 10 cm or more, the axial thickness T of the open cell is 1 mm or more, and the thickness / major axis ratio T / L is 0.5 or less. The honeycomb-shaped ceramic structure according to claim 1 or 2, wherein 4. The honeycomb ceramic structure according to claim 1, wherein at least one of the honeycomb ceramic modules has a different form from other modules. 5. The open cells that communicate with each other form a substantially spiral fluid passage.
4. The honeycomb-shaped ceramic structure according to any one of 4 above. 6. The cross-sections of the open-cells of the honeycomb-shaped ceramic modules are circular and identical to each other, and the respective honeycomb-shaped ceramic modules are rotated or staggered with respect to each other about the center of the cross-section of the open-cells. And the communicating open cells form a substantially helical fluid passage.
5. The honeycomb-shaped ceramic structure according to any one of 5 above. 7. A shock absorbing layer having open cells so as to absorb at least one mechanical or / and thermal stress between the honeycomb-shaped ceramic modules or / and on the end face of the honeycomb-shaped ceramic structure. 7. A honeycomb ceramic structure according to any one of claims 1 to 6, wherein a material is provided. 8. The honeycomb ceramic structure according to any one of claims 1 to 7, wherein the honeycomb ceramic structure is a catalyst carrier. 9. The honeycomb-shaped ceramic structure according to claim 8, wherein at least one of the honeycomb-shaped ceramic modules carries a catalyst different from that of other modules. 10. The honeycomb ceramic structure according to claim 8, wherein each of the honeycomb ceramic modules is one or more of an oxidation catalyst carrier, a reduction catalyst carrier and a fine particle adsorbing porous material. 11. The honeycomb-shaped ceramic structure is a catalyst carrier for automobile exhaust gas.
10. The honeycomb ceramic structure according to any one of 10 to 10. 12. The honeycomb ceramic structure according to claim 1, wherein at least one of the honeycomb ceramic modules is made of a different ceramic material from other modules. 13. A ceramic raw material and a raw material containing an organic fiber as a main component are fired.
2. The honeycomb-shaped ceramic structure according to any one of 2. 14. A ceramic raw material and a raw material containing inorganic fibers as main components are fired.
3. The honeycomb-shaped ceramic structure according to any one of 3 above. 15. The honeycomb ceramic structure according to claim 1, wherein an outer peripheral surface of the honeycomb ceramic structure is wrapped with a sheet film or a tubular body made of a metal. body.