JP2002349714A - Complex with sealing performance and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a complex that is suitably used in a device for manufacturing pure oxygen, oxygen-enriched air or the like, a membrane reactor typically for partial oxidation of hydrocarbon gas, a solid oxide fuel cell, an oxygen purifier, a heat exchanger and the like, by establishing a sealing technique capable of simple seal formation and excelling in reliability and a heat cycle characteristic in a high-temperature range of 800 deg.C and higher. SOLUTION: The complex comprises a structure with a storing portion formed by a combination of a plurality of members 1 and 2, and a metal member 3. The metal member 3 fills the storing portion of the structure, and the metal member 3 fills a part or the whole of a combination boundary portion 4 of the members 1 and 2 forming the structure, to provide excellent sealing performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite exhibiting excellent sealing properties at high temperatures. The composite is suitably used for production equipment for pure oxygen, oxygen-enriched air, etc., diaphragm reactors represented by partial oxidation of hydrocarbon gas, solid oxide fuel cells, oxygen purification equipment, heat exchangers, etc. You.

[0002]

2. Description of the Related Art A sealing technique in a high temperature range exceeding 800 ° C. will be described below with reference to an example. First, the production of pure oxygen and the production of oxygen-enriched air will be described. This technology is
Supplying inexpensive oxygen or oxygen-enriched air to fields that consume large amounts of oxygen, such as steelmaking, glass, and cement, has enormous economic effects. The principle of producing pure oxygen or oxygen-enriched air using mixed conductive oxides that have both oxide ion conductivity and electron conductivity is based on the isolation of two types of gases with different oxygen partial pressures. This is based on the phenomenon that oxygen permeates oxides in the form of oxide ions from the higher oxygen partial pressure side to the lower oxygen partial pressure side.

For example, by compressing an oxygen-containing mixed gas (such as air) and setting the oxygen partial pressure higher than that of a recovered gas (pure oxygen or oxygen-enriched air), the oxygen gas is separated from the oxygen-containing mixed gas. . The efficiency of separating oxygen gas greatly depends on the oxide ion conductivity when the mixed conductive oxides have the same thickness. An area is selected. If the gas sealing property is low in this temperature range, there arise problems that the purity of the obtained oxygen decreases and the production efficiency of oxygen-enriched air decreases.

[0004] As a second example, a membrane reactor typified by partial oxidation of a hydrocarbon gas using a mixed conductive oxide will be described. From the viewpoint of effective utilization of natural resources, natural gas liquid fuel technology (gas to liquid = GTL) has been attracting attention, but this technology is important as its elemental technology. The principle of the diaphragm reactor is to separate the oxygen-containing gas (for example, air) and the hydrocarbon gas (for example, natural gas mainly composed of methane) from the air side to the hydrocarbon gas side by separating them with a mixed conductive oxide. Oxygen permeates the oxide and oxidizes the hydrocarbon gas on the oxide surface on the hydrocarbon gas side to obtain a synthesis gas (mixed gas of carbon monoxide and hydrogen) and a partial oxidant. As with the oxygen production described above, the operating temperature is 800
° C or higher is selected. If the gas sealing property is low in this temperature range, not only will the reaction efficiency decrease be a major factor,
In extreme cases, complete combustion of hydrocarbons occurs at once, and there is a risk of explosion.

[0005] As a third example, a solid oxide fuel cell using an oxide ion conductive oxide, which has attracted attention for its high power generation efficiency and a clean environment-friendly power generation system, will be described. This technology uses waste heat for co-generation to operate fuel cells at high temperatures.
Ultimately, it has the advantage that a total energy efficiency of 70-80% can be expected, and it is currently being actively researched and developed. The operating principle of a solid oxide fuel cell is to separate fuel gas such as hydrogen and air from each other with an oxide ion conductive oxide, and to obtain electric power by moving oxide ions through the oxide.
Yttria stabilized zirconia currently under development
(YSZ) is known to have a high ionic conductivity among oxide ion conductive oxides, but is lower than the mixed conductive oxides described above. Therefore, the operating temperature range of the solid oxide fuel cell using YSZ is 900 ° C. or higher. Also in the present technology, if the gas sealing property is low, it may be the largest cause of the output decrease or may cause the worst situation such as explosion.

As described above, the sealing technology in a high temperature region exceeding 800 ° C. has a very important meaning, and various sealing methods have been devised, but most of them are the most developed fuel cells. You can see in the field.

[0007] In the case of a flat-type fuel cell, it is necessary to seal between the battery cell and the separator (or interconnector). As a sealing material, various types of glass such as a ceramic adhesive, borosilicate glass and sodium silicate glass, a heat-resistant metal gasket, and a sintered body obtained by firing fine oxide powder are known.

In Japanese Patent Application Laid-Open No. 5-325999, the solid phase forms a matrix in the solid-liquid coexistence range from the solidus line to the liquidus line by controlling the composition ratio of sodium silicate glass, and the liquid layer is sealed. A sealing material comprising a binary or higher oxide functioning as a material is disclosed.

Japanese Patent Application Laid-Open No. 6-231784 discloses a sealing material in which a metal foil reinforced with ceramic fibers is used as an aggregate, and the aggregate holds sodium silicate glass.

In JP-A-8-7904, the compatibility between the separator and the vitreous sealing material is improved and the sealing property is improved by preliminarily heat-treating the separator in an oxygen atmosphere to form an oxide layer on the surface. Let me.

In Japanese Patent Application Laid-Open No. Hei 9-155530, a separator and a mortise joint are provided on the upper and lower surfaces of a separator to fit them, and a gasket of a heat-resistant metal is provided between the separator and the solid electrolyte. And a method for ensuring airtightness by inserting and contacting with each other.

JP-A-10-116624, JP-A-10-12252
JP-A-11-154525 and JP-A-11-154525 disclose a solid electrolyte fuel cell using a sintered body of a raw material powder mainly composed of an ultrafine oxide having a melting point higher than the operating temperature of the solid electrolyte fuel cell as a sealing material. Is disclosed.

Japanese Patent Application Laid-Open No. 9-129251 discloses a sealing method in which a material containing both components of two materials to be joined is used as a sealing material in a solid oxide fuel cell. The above-mentioned technology is directed to a flat fuel cell. On the other hand, in the case of a cylindrical fuel cell, it is necessary to seal between a cylindrical cell and a partition plate holding the cell.

JP-A-5-29010 and JP-A-5-29011
This publication discloses a solid electrolyte fuel cell using glass for sealing between a cylindrical cell and a flange and between a flange and a gas seal plate (partition plate).

Further, regarding sealing technology in fields other than fuel cells, see PS Maiya et al. (US Patent 5,725,21).
8) discloses a sealing technique between Inconel and a solid electrolyte (SFC-2) in a diaphragm reactor for partial oxidation of methane. SrO, B ₂ O ₃ , SrFeCo as sealing material
A mixed powder of _0.5 O × oxide is selected and melted by heating to provide a sealing property.

[0016]

As described above, as described above, 800
The technology of gas sealing in a temperature region exceeding ° C. has enormous economic effects, and at the same time, is an essential technology in developing a state-of-the-art technology for solving environmental problems.

However, in the prior art, there is still room for improvement in reliability and thermal cycling, although considerable effort is required to form the seal, and the seal can be easily formed. In addition, there has been a strong demand for the establishment of a sealing technique which is excellent in reliability and thermal cyclability.

One of the factors that makes sealing technology difficult is due to the inherent coefficient of thermal expansion of the material. That is, since the operating temperature range is extremely high, even if the difference in the coefficient of thermal expansion of the bonding material is not so large, the difference becomes more pronounced at higher temperatures.

Here, for typical materials, linear thermal expansion
The coefficients are listed below. Perovskite oxide
Mixed conductive oxides generally have very large linear thermal expansion
Have a number. For example, high oxygen ion conductivity
Temperature of La-Sr-Co-Fe mixed conductive oxides
From 800 ° C to the average linear thermal expansion coefficient is (La_{0 .2}Sr_0.8) (Co
_0.8Fe_0.2) About 26 × 10 for O ×^-6/ ° C and (La_0.2Sr
_0.8) (Co_0.4Fe_0.4Cu_0.2) About 20 × 10 for O ×^-6/ ℃
You. In contrast, the metal is 17.5 stainless steel SUS310S.
× 10^-6/ ℃ (average of 0-650 ℃), Incoloy (Incoloy 800)
14.2 × 10^-6/ ° C (average of 0-100 ° C) and coefficient of linear thermal expansion
Is smaller, about 10 × 10 in YSZ^-6/ ℃ (0-1000 ℃ flat
(Average). For glass, 1 × 10^{- 6}
/ ° C (average of 20-1000 ° C), extremely small linear thermal expansion
Is shown. Conventional technology using glass as a sealing material
Because the glass part melts at an operating temperature exceeding 800 ° C,
Utilizing the fact that a highly airtight liquid seal can be realized
It is.

However, when the molten glass is used as the sealing material, the sealing material elutes from the joint during use, or the glass is isolated as in the above-described pure oxygen production.
If the pressures of the types of gases are not the same, there arises a problem that the molten glass cannot withstand the pressure difference. In addition, glass materials cannot provide high bonding strength, cannot be used for long-term use at high temperatures, and undergoes deterioration of the sealing material such as evaporation of components and crystallization, and cannot provide stable properties. For this reason, there have been problems that the sealing property cannot be maintained after several heat cycles, and a chemical reaction occurs with a material to be joined (particularly, an oxide solid electrolyte) to deteriorate the material to be joined.

The aforementioned JP-A-10-116624 and JP-A-10-116624
No. 12252, JP-A-11-154525, JP-A-9-129251
No. 5,725,218, the thermal expansion coefficient of the sealing material is close to the thermal expansion coefficient of the two types of materials to be joined, so the problem caused by the difference in the thermal expansion coefficient is solved, and long-term use at high temperature is solved. The purpose of the present invention is to provide stable gas sealability and heat cycle resistance.

However, the firing temperature of the sealing material may be close to the firing temperature of the two materials to be bonded, or may be higher than the firing temperature of one of the materials to be bonded depending on the combination. There has been a problem that the bonding material is damaged by heat. In addition, there are problems such as a time-consuming method of preparing and sintering a sealing material each time, and leaving a room for improvement in sealing properties, and have not yet been put to practical use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a seal which can be easily formed in a high temperature region of 800 ° C. or more, and has a seal excellent in reliability and heat cycle characteristics, and production of the composite. It is an object of the present invention to provide a method and an apparatus using the composite.

[0024]

The gist of the present invention for solving the above-mentioned problems is as follows. (1) A composite including a structure having a storage portion formed by combining a plurality of members, and a metal member, wherein the metal member is filled in the storage portion and forms the structure. A composite having sealing properties, characterized in that a part or all of a combination boundary of members is filled with the metal member.

(2) The composite having sealing properties according to (1), wherein the softening temperature of the metal member is lower than the softening temperature of the members constituting the structure.

(3) The composite having sealability according to (2), wherein the metal member is silver or a silver alloy.

(4) Each of the members constituting the structure is made of ceramic or metal, and the structure is formed of ceramics, metals, or a combination of ceramic and metal. A) a composite having the sealing property described in the above);

(5) The average linear thermal expansion coefficient from room temperature to 850 ° C. of the member constituting the structure is 16 × 10 ⁻⁶ / ° C.
The composite having a sealing property according to claim 4, which is not less than 26 × 10 ^-6 / ° C.

(6) The seal according to any one of claims 1 to 5, wherein a part of the member constituting the structure is an oxide material having an oxide ion permeability. Complex having properties.

(7) A composite of silver or a silver alloy and a structure having at least a combination of a hollow member and a flange member having an oxide ion-permeable oxide layer and one end of which is sealed, The structure has a storage portion formed by combining an open end of the hollow member and the flange member, and has a sealing property characterized by being filled with the silver or silver alloy in the storage portion. Complex having.

(8) A composite comprising a member having a circumferential concave portion and a member having a convex portion insertable into the concave portion, wherein each member is at least one member selected from metal and ceramics. A composite having a sealing property, comprising a seed, wherein a storage portion formed by inserting the convex portion into the concave portion is filled with silver or a silver alloy.

(9) A step of forming a structure having a storage portion by combining a plurality of members, and at least one member selected from a metal member or a metalized member softened at a lower temperature than the members constituting the structure. Inserting the metal material into the storage portion, and heating at least the storage portion to a temperature range equal to or higher than the softening temperature of the metal material inserted into the storage portion and lower than the softening temperature of the member constituting the structure. And solidifying the metal material while filling the metal material into at least one of the combination boundaries of the storage portion and the members constituting the structure. How to make the body.

(10) The metal material inserted into the storage section is selected from silver, a silver alloy, a clay containing silver, a clay containing a silver alloy, a slurry containing silver, and a slurry containing a silver alloy. The method for producing a composite having sealability according to (9), which is a seed.

(11) An oxygen separator comprising the composite having a sealing property according to any one of (1) to (8).

(12) A diaphragm reactor comprising the composite having a sealing property according to any one of (1) to (8).

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments to which the present invention is applied will be described below in detail with reference to the drawings.

-Structure of the Composite-First, the "reservoir" formed by combining a plurality of members of the present invention means that when a material that flows while only the gravitational field is working is disposed, the flowing material does not flow out. And does not include cases where a force other than gravity (eg, centrifugal force) is applied.

Next, a preferred embodiment of the present invention is shown in FIG. FIG. 1 is a schematic cross-sectional view of a composite of a metal member and a structure having a storage portion formed by combining a plurality of members. In any case, the metal member is filled in the storage portion of the structure, and the metal member is filled in a part or the entirety of a combination boundary portion of members forming the structure.

FIGS. 1A, 1B, and 1C show two members (1, 2).
The composite of the structure consisting of 2) and the metal member 3
3 seals the boundary 4 between the member 1 and the member 2.
1 (d), (e), and (f) show a composite of a metal member 8 and a structure composed of three members (5, 6, 7). The boundary 9 and / or the boundary 10 between the members 5 and 7 are sealed.

The metal member is selected to have a lower softening temperature than all the members forming the structure. That is, the metal member 3 is a member that softens at a temperature lower than any of the members 1 and 2, and the metal member 8 is a member that softens at a temperature lower than any of the members 5 to 7.

As described above, the metal member used in the present invention is not limited as long as it has a lower softening temperature than all members of the structure having the storage portion formed by combining a plurality of members. However, silver or a silver alloy is preferably used for the following two reasons, especially when all the members forming the structure are stable materials without softening at 1000 ° C. The first reason is that the melting point of silver is 961
° C, and the melting point of the silver alloy is also in the vicinity of this, so that the relationship of the softening temperature falls within the range of the present invention. The second reason silver or silver alloys are used is due to the chemical properties of silver. Silver has the property that the oxide is stable from room temperature to about 200 ° C., but above that temperature, it releases oxygen to stabilize the metal. That is, even if heat treatment is performed in the air, the metal state is maintained at a high temperature, so that the oxide grows on the interface with the members forming the structure, thereby impairing the sealing performance at the boundary between the combined members. This is because a highly reliable seal can be realized.
Further, due to the chemical stability of silver, the members to be joined do not suffer from a chemical reaction and are not deteriorated in characteristics.

The composition of the silver alloy may be any composition, but in order not to impair the characteristics of silver described here, it is desirable that the silver component is 35% by mass or more. Components other than silver include, for example, Cu, Zn, Pb, Cd, Ni, S
n, Mn, Li, In, Pd, Ti, Cr and the like can be blended.

The materials of the members 1, 2, 5 to 7 forming the structure are ceramics or metals, respectively. The structure having a storage portion formed by combining a plurality of members is made of at least two materials. Has become. When a silver-based material is used as the metal member of the present invention, the plurality of members forming the structure have an average linear thermal expansion coefficient from room temperature to 850 ° C. of 16 × 10 ⁻⁶ / ° C. or more. 26 × 10 ^-6 /
Desirably, it has a temperature of not more than ° C. This is because the average linear thermal expansion coefficient of a silver-based material from room temperature to 850 ° C is 23 × 1
Because the temperature is about 0 ⁻⁶ / ° C., if the above range is not satisfied, a stress is generated based on a difference in thermal expansion, which leads to a reduction in seal reliability. Further, it is preferable that the plurality of members forming the structure have an average linear thermal expansion coefficient as close as possible to each other. On the other hand, in the present invention, 800
In order to provide a composite characterized by a sealing structure that can maintain sealing properties even at high temperatures exceeding ℃, materials other than ceramics and metals, such as polymer materials, which do not have heat resistance, are structural members. It is not preferable as a member for forming.

When the composite of the present invention is used in an apparatus for producing pure oxygen, oxygen-enriched air, etc., a membrane reactor typified by partial oxidation of hydrocarbon gas, a solid oxide fuel cell, or the like, The member to be formed includes an oxide material that is permeable to oxide ions. Examples of oxide ion-permeable oxide materials include oxide ion conductors such as bismuth oxide, ceria, and zirconia, and oxide ions such as zirconia including perovskite oxide, pyrochlore oxide, and ceria. 1 at 850 ° C, such as electronic mixed conductors
An oxide having an oxide ion conductivity of 0 ^-2 Scm ^-1 or more is preferably used, but an oxide having a conductivity of less than this may be used depending on the application.

When the composite of the present invention is used in an apparatus for producing pure oxygen, oxygen-enriched air, etc., a membrane reactor typified by partial oxidation of hydrocarbon gas, or a solid oxide fuel cell, etc. In order to increase the amount and increase the production efficiency, reaction efficiency, or power generation efficiency, it is important to increase the oxide ion permeation area as much as possible. FIG. 2 shows a preferred specific example of the composite for that purpose.

In the embodiment shown in FIG. 2, a hollow member 11 having an oxide layer that is permeable to oxide ions is sealed at one end, and a flange member 12 having an outer diameter larger than the outer diameter of the hollow member 11 is combined. FIG. 2 is a schematic cross-sectional view of a composite of a structure and silver or a silver alloy 13. In any case, a storage portion is formed by combining the open end of the hollow member and the flange member, and the storage portion is filled with silver or a silver alloy, whereby the boundary portion 14 between the hollow member 11 and the flange member 12 is sealed. . By arranging these composites in a certain space with a high degree of integration, the transmission area can be dramatically increased.

In the composite shown in FIG. 2, the cross-sectional shape of the storage portion formed by the plurality of members is rectangular. However, the cross-sectional shape of the storage portion as shown in FIG. Other shapes may be used.

FIG. 2 (j), FIG.
Alternatively, FIG. 3 (o) shows a shape in which the flange member 12 is also inserted into the cylinder of the hollow member 11;
Can be fixed more stably. In addition, this structure not only stably fixes the hollow member, but also prevents the metal material softened in the storage portion from flowing out even when a part of the boundary portion 14 is opened for some reason. It is effective in forming a more reliable composite. As a similar structure, a core member 15 may be provided separately from the flange member 12 as illustrated in FIG. 2 (k) or FIG. 3 (p).

Further, as illustrated in FIG. 3 (q), another member 16 may be combined with the flange member 12 to form an L-shaped cross section of the storage portion formed by the plurality of members.

The hollow member 11 is in the form of a cylinder having one end sealed and containing an oxide layer permeable to oxide ions, where oxide ions are selectively permeated. Therefore, the hollow member 11
May consist only of an oxide layer that is permeable to oxide ions. In this case, the entire hollow member must be sufficiently densified so that substances other than oxide ions do not pass through the oxide layer. Otherwise, even if a composite having excellent sealing properties is provided, impurities other than oxide ions diffuse through the hollow member 11 and cause a reduction in production efficiency, reaction efficiency, or power generation efficiency. Becomes

As a method for producing a dense hollow member, a general method for producing a ceramic tube is used as it is. That is, the raw material powder is weighed and mixed so as to have a predetermined composition, calcined, pulverized, and then molded. For molding, a general method such as an isostatic pressing method (rubber press method), an extrusion molding method, a plasma casting method, or the like can be applied.

On the other hand, the oxide ion-permeable oxide layer is
It may be a hollow member having a structure formed on a cylindrical porous body having one end sealed. In this case, the thinner the oxide-ion-permeable oxide layer is, the more advantageous it is in order to increase the transmission efficiency. On the other hand, as the thickness becomes thinner, it becomes more difficult to prevent the passage of substances other than oxide ions. This is because, if defects such as slight cracks and minute pinholes exist in the oxide layer, substances other than oxide ions easily penetrate the oxide layer because the oxide layer is thin. In such a case, the oxide layer that is permeable to oxide ions may be formed thicker. Further, as described in the embodiment, partial repair processing of the oxide layer can be performed, and the hollow member 11 may have such a repair layer.

The material of the cylindrical porous body having one end sealed is not limited as long as it has heat resistance and does not cause an extreme reaction with the oxide layer formed thereon. Is an oxide of the same series as the oxide layer formed thereon. This is because the thermal expansion coefficient of the oxide layer and that of the porous body are well matched, so that the stress generated in the oxide layer can be minimized, and a more reliable oxide ion-permeable oxide layer Is formed.

In order to form an oxide ion-permeable oxide layer on a cylindrical porous body having one end sealed, first,
A porous body is manufactured as follows. After passing through a process of kneading and calcining the raw material powder, for example, a fine powder of polyvinyl alcohol is mixed with the calcined powder in the same manner as in ordinary ceramic synthesis, followed by molding and firing. This is because the polyvinyl alcohol fine powder is removed by oxidation and vaporization at the firing stage, and the remaining ceramic portion is sintered to form a rigid network and become porous. When producing porous ceramics, the fine powder to be mixed with the calcined powder need only be removed in the firing step, and thus may not be polyvinyl alcohol, and may be other organic compounds, carbon powder, or walnut. Shells and even sawdust may be used. However, the particle size of the organic material mixed with these calcined powders is appropriately selected according to the use since it depends on the ventilation performance and mechanical strength of the porous body.

There are various formation methods for the oxide ion-permeable oxide layer formed on the porous body. For example, using a slurry obtained by dispersing the calcined powder in a solvent, it may be applied or immersed in the porous body and fired, or calcined powder is deposited by an electrophoretic electrodeposition method and the like and fired. You may. In addition to these wet methods, the vapor phase method, CVD
Alternatively, a thin film manufacturing method such as the above may be used.

As the material of the flange member 12, any material having heat resistance may be used, and a wide variety of materials such as stainless steel made of iron, chromium, and nickel, a copper alloy, a heat-resistant alloy, and ceramics can be used. However, 800
Since use at a high temperature exceeding ℃ is premised, the member itself is not extremely oxidized or melted under high temperature conditions, and there is no deterioration when viewed as a structural member, which is a limitation related to the member of the flange member 12. . Desirable materials are ceramics and heat-resistant alloys, but the most desirable material is the same material as the hollow member 11. Good thermal expansion coefficient matching,
This is because the heat cycle property is particularly excellent.

FIG. 4 is a schematic cross-sectional view of a composite in which a member 17 made of metal or ceramic having a circumferential concave portion and a member 18 made of metal or ceramic having a convex portion insertable into the concave portion are combined. Show. In any case, silver or silver alloy 19 is stored in the storage portion formed by inserting the convex portion into the concave portion.
Is filled, the boundary 20 between the two members (17, 18)
Is sealed.

As shown in FIGS. 1 to 4, in the composite of the present invention, the upper surface of the metal member is a free surface. This structure makes it easy to replenish the metal members even if the metal members that maintain the sealing properties have a very small sublimation speed, but the metal members gradually decrease due to long-term use and the sealing properties cannot be maintained. Provides benefits that can be Also, depending on the combination of the composite member and the metal member to be joined, the wettability may be extremely poor. In an extreme case, the metal member cannot completely cover the boundary portion, and the sealing property may not be exhibited. In such a case, if the additive element for improving the wettability is replenished and the heat treatment is performed again, the wettability at the boundary can be improved and the sealing property can be imparted. Problems are easy to deal with.

The composite of the present invention is desirably used at a temperature lower than the softening temperature of the metal member. This is because the loss of the fluidity of the metal member enables extremely excellent differential pressure resistance. In order to use the composite at a temperature lower than the softening temperature of the metal member, a metal member having a softening temperature slightly higher than the temperature at which the composite is used may be appropriately selected. For example, when the composite is used at about 800 to 900 ° C., silver or a silver alloy is preferably used.

—Method for Producing Composite— The composite of the present invention can be produced as follows. That is, after forming a structure having a storage portion by combining a plurality of members, after inserting a metal member and / or a metalization member that softens at a lower temperature than the structure forming member into the storage portion, The storage unit is heated to a temperature range equal to or higher than the softening temperature of the metal member and / or the metallization member and lower than the softening temperature of the structure forming member, and the metal member and / or the metallization member is heated to the storage unit and / or It is made into a metal member (hardened) while filling the boundary of the combination of the members forming the structure. The reservoir functions to prevent the metal member contributing to the sealing performance from flowing out at the softening temperature.

Since the metal member is caused to flow once by heat treatment and then filled into the combined boundary portion of the members forming the storage portion and / or the structure, the metal member is ingot, powder, granular, or linear in a size corresponding to the shape of the storage portion. Or any other shape. Further, clay or slurry containing metal powder to be inserted may be used. In this case, the metal member and the softening treatment may be performed separately, but by performing the heat treatment continuously,
The metal member can be filled at one time at the combined boundary of the members forming the reservoir and / or the structure.

-Configuration of Oxygen Separator- Next, FIG. 5 shows an example of an oxygen separator using the composite having excellent sealing properties according to the present invention. This is an example of an oxygen production apparatus that transports only oxygen ions from pressurized air to obtain pure oxygen at normal pressure. Although two composites are shown in the figure for convenience, the basic configuration does not change even if more composites are installed.

The hollow member 21 has a structure in which a boundary 24 with the flange member 22 is sealed by silver or a silver alloy 23. In addition, the present device includes a core member 25 that assists in fixing the hollow member 21 and that prevents silver or silver alloy 23 from flowing out in the unlikely event that the hollow member 21 is fixed. The structure composed of 21 to 25 is attached to the stacking plate 26, and a boundary 28 with the stacking plate 26 is sealed by silver or a silver alloy 27. Further, the accumulation plate 26 is attached to the oxygen separation container 29, and by silver or silver alloy 30,
A boundary portion 31 with the oxygen separation container 29 is sealed.

In this structure, the oxygen separation vessel 29 heated to a high temperature (for example, 850 ° C.) is divided into a region 32 and a region 33 by the combination of the composite of the present invention. This device is basically present in the region 32 because oxygen is separated and recovered from the region 32 to the region 33 by the cylindrical hollow member 21 having one end sealed and containing an oxide layer permeable to oxide ions. The partial pressure of oxygen to be applied may be set higher than the partial pressure of oxygen in the region 33. For example, if air pressurized to 1MPa is introduced into the area 32, the oxygen partial pressure in the area 32 will be higher than 0.1MPa. Therefore, it is necessary to separate and collect in the area 33 at normal pressure (normal pressure oxygen = 0.1MPa). Becomes possible. At this time, since the three types of boundaries (24, 28, 31) are sealed with silver or a silver alloy (23, 27, 30), the two regions (32, 33) do not mix, Oxygen is separated and recovered. And the area
By always supplying fresh air to 32, oxygen separation can be maintained for a long time. A method of maintaining a constant pressurized state while supplying fresh air is, for example, a method in which air pressurized by a booster is supplied at a constant flow rate from the inlet 34 by a flow rate control device, and the oxygen concentration is reduced by oxygen separation. This can be realized by discharging the depleted air from the outlet 35 using a back pressure valve (not shown).

As the pressure of the pressurized air in the region 32 becomes higher, the driving force of the oxygen permeation becomes larger, so that the separation speed can be increased. There is a risk that body components may be damaged. On the other hand, if the pressure of the pressurized air is too low, the oxygen partial pressure falls below 0.1 MPa, and oxygen cannot be separated. Further, even if the oxygen partial pressure is set to a level slightly higher than 0.1 MPa, the oxygen concentration on the air side is reduced by the separation, and a driving force for effectively transmitting oxygen is hardly generated. To avoid this, the supply of fresh air to be supplied may be increased indefinitely so that the decrease in oxygen concentration can be substantially ignored, but this is not practical. Therefore, the air pressure suitable for oxygen separation (in parentheses-oxygen partial pressure) is 0.5 MPa (0.105 MPa) or more, 3 MPa (0.63 MPa) or less, more preferably 0.6 MPa (0.126 MPa) or more. 2MPa
(0.42 MPa) or less.

As described above, the hollow member 21 having an oxide ion-permeable oxide layer and closed at one end may be composed of only an oxide ion-permeable oxide layer,
A structure in which an oxide ion-permeable oxide layer is formed on a cylindrical porous body having one end sealed may be used. Further, a repair layer may be formed on the oxide layer that is permeable to oxide ions. In any case, the structure is such that only oxide ions are transported and other gas components are not permeated.

In the example shown in FIG. 5, the flange member 22 and the accumulation plate 26 are made of different materials, and silver or a silver alloy 27 is used in order to realize a sealing property between them. This structure is more convenient when it is assumed that maintenance (exchange or the like) is performed using the composite of the hollow member 21 and the flange member 22 as one unit. On the other hand, when importance is attached to the simplicity of the device structure rather than such convenience, the hollow member 21 is directly combined with the accumulation plate 26, and silver or silver alloy is used.
If the structure is used to seal the boundary using 27, 22 to 25 can be omitted.

-Constitution of Diaphragm Reactor- Next, FIG. 6 shows an example of a diaphragm reactor using the composite having excellent sealing properties according to the present invention. In this method, natural gas containing methane as a main component and air are separated by an oxide-permeable oxide, and oxygen ions transported from the air side to the natural gas side convert methane on the oxide surface on the natural gas side. This is an example of an apparatus for obtaining a synthesis gas (carbon monoxide and hydrogen) by partial oxidation.
Although two composites are illustrated in the figure for convenience, the basic structure does not change even if more composites are installed. Further, oxygen may be used instead of air.

The hollow member 37 has a structure in which the boundary 40 with the flange member 38 is sealed by silver or a silver alloy 39. In addition, the present device includes a core member 41 that assists in fixing the hollow member 37 and prevents the silver or the silver alloy 39 from flowing out in the unlikely case. The structure consisting of 37 to 41 is attached to the collecting plate 42, and the boundary 44 between the collecting plate 42 and the collecting plate 42 is sealed by silver or a silver alloy 43. Further, the stacking plate 42 is attached to the reactor container 45, and a boundary 47 between the collecting plate 42 and the reactor container 45 is sealed by silver or a silver alloy 46.

In this structure, the reactor vessel 45 heated to a high temperature (for example, 850 ° C.) is divided into a region 48 and a region 49 by the combination of the composite of the present invention. The present device supplies air from the air inlet 52, passes through the hollow member 37 having one end sealed with an oxide ion-permeable oxide layer, and the oxide ions are supplied to the region 48 where natural gas is present. The natural gas is transported and partially oxidized on the surface of the hollow member 37. Since the region 48 has a remarkably low oxygen partial pressure due to the reducing gas, the region 48 may be in a normal pressure or a pressurized state. Since the region 49 side has an extremely high oxygen partial pressure, the pressure may be increased or the atmospheric pressure may be maintained. At this time, if the sealing property of the composite is poor, the gases in both regions are mixed on the surface other than the surface of the hollow member 37, such as a complete oxidation reaction, and the desired reaction cannot be controlled, or in the worst case, Explosion hazard due to mixing. In the case of the present composite, the three kinds of boundaries (40, 44, 47) are sealed by silver or silver alloy (39, 43, 46), so that the composite can be operated as a highly efficient reactor.

When maintaining a constant pressurized state while supplying natural gas, similarly to the case of the oxygen separator, for example, pressurized natural gas is supplied at a constant flow rate from the inlet 50 by a flow rate control device. The synthesis gas generated by partial oxidation is
It can be realized by discharging from the discharge port 51 using a back pressure valve (not shown). On the other hand, when maintaining a constant pressurized state while supplying air, the pressurized air is supplied at a constant flow rate from the inlet 52 by the flow rate control device, and does not contribute to the permeation of the hollow member 37 and has poor oxygen content. It can be realized by discharging the pressurized air from the outlet 53 using a back pressure valve (not shown).

The pressure balance between the region 48 and the region 49 is not particularly limited as in the case of the oxygen separator. However, the natural gas introduced into the region 48 is originally supplied at a high pressure, and the recovered synthesis gas is often subjected to a subsequent reaction at a high pressure. To work with. The pressurizing range is selected in consideration of the load applied to the reactor, but is generally about 3 MPa or less, preferably about 2 MPa or less. On the other hand, the air to be introduced into the region 49 is desirable in that the pressure difference between the two regions can be minimized by being pressurized and introduced to the same degree as that of natural gas. The pressure conditions are determined as appropriate.

As described above, the hollow member 37 having an oxide ion-permeable oxide layer and closed at one end may be composed of only an oxide ion-permeable oxide layer,
A structure in which an oxide ion-permeable oxide layer is formed on a cylindrical porous body having one end sealed may be used. Further, a repair layer may be formed on an oxide layer permeable to oxide ions. In any case, the structure is such that only oxide ions are transported and other gas components are not permeated. Further, a catalyst layer for partially oxidizing methane is formed on the outermost surface of the hollow member 37 on the natural gas side. Any material may be used for the catalyst layer as long as it has a catalytic activity. For example, generally known materials such as Ni and Ru are preferably used.

In the example shown in FIG. 6, the flange member 38 and the accumulation plate 42 are made of different materials, and silver or a silver alloy 43 is used in order to realize a sealing property between them. This structure is more convenient when it is assumed that maintenance (exchange or the like) is performed with the composite of the hollow member 37 and the flange member 38 as one unit. On the other hand, when importance is placed on the simplicity of the device structure from such convenience, if the hollow plate 37 is directly combined with the accumulation plate 41 and the boundary portion is sealed using silver or a silver alloy, a structure 38 ~ 41 can also be omitted.

[0075]

EXAMPLE An oxygen separator illustrated in FIG. 5 was actually assembled as follows. That is, the hollow member 21 has a structure in which an oxide ion-permeable oxide layer is formed on a cylindrical porous body having one end sealed, and the flange member 22 and the core member 25 are made of SUS304, , And oxygen separation vessel 29 is SU
S310S was used. For the hollow member 21, an oxide ion-permeable oxide layer having a thickness of about 50 μm was formed on the porous body by using a slurry coating method. The porous body and the oxide layer formed thereon were oxides of the same composition. In addition, silver clay was inserted into the storage part formed by combining a plurality of members, and heat treatment was performed at the softening temperature of silver to form silver 23, 27, and 30.

The pressure of the compressed air in the region 32 is maintained at 1 MPa,
When the experiment was performed at 850 ° C., it was confirmed that 600 cc of oxygen was separated and generated per minute. The purity of the obtained oxygen is about 98%
It was found that nitrogen gas of 2% was mixed.However, when the cause was investigated in detail, it was found that the oxide ion permeable oxide layer formed on the porous body of the hollow member 21 had an extremely small amount. A slight gas leak was observed.

Therefore, the surface of the hollow member 21 except for the open end was immersed in the slurry used in the slurry coating method, and the inside of the hollow member 21 was depressurized to selectively repair the leaked portion. After the repair, the hollow member 21 obtained by firing has not changed the thickness of the oxide ion-permeable oxide layer, and confirmed in the same experiment as above that oxygen can be separated at almost the same rate. , The leak is completely suppressed, 99.999
We succeeded in obtaining oxygen with a purity of more than 10%. From this, it was confirmed that there was no leakage at the boundary existing in the composite, and complete sealing at high temperatures could be realized.

After the oxygen separator was cooled to room temperature, a heat cycle of raising the temperature to 850 ° C. again was added 10 times,
When the experiment was repeated at 50 ° C., it was confirmed that the first experiment could be completely reproduced.

[0079]

According to the present invention, it is possible to provide a composite having excellent sealability having high reliability at a high temperature, and has been put to practical use in a wide range of fields where development has been delayed due to improvement in sealability. Can be increased. In particular,
Speed up development by applying to production equipment for pure oxygen, oxygen-enriched air, etc., diaphragm reactors represented by partial oxidation of hydrocarbon gas, solid oxide fuel cells, oxygen purification equipment, heat exchangers, etc. Can greatly contribute to

[Brief description of the drawings]

FIG. 1 is a preferred specific embodiment of the present invention, and is a schematic cross-sectional view of a composite of a metal member and a structure having a storage portion formed by combining a plurality of members.

FIG. 2 is a schematic cross-sectional view of another preferred embodiment of the present invention, a composite effective to increase the permeation area of oxide ions.

3 is a schematic cross-sectional view of another preferred embodiment of the composite shown in FIG. 2, which is effective for increasing the permeation area of oxide ions.

FIG. 4 is an example of a composite including a structure in which a member made of metal or ceramic having a peripheral concave portion and a member made of metal or ceramic having a convex portion insertable into the concave portion are combined. FIG. 3 is a schematic cross-sectional view of a composite of a structural member made of a member and a metal member.

FIG. 5 is a diagram showing an example of an oxygen separator using a composite having excellent sealing properties according to the present invention.

FIG. 6 is a view showing an example of a diaphragm reactor using a composite having excellent sealing properties according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 One member which forms the structure which has a storage part 2 Another member which forms the structure which has a storage part 3 Metal member 4 The boundary part of the member 1 and the member 2 5 One which forms the structure which has a storage part Member 6 Another member forming a structure having a storage portion 7 Still another member forming a structure having a storage portion 8 Metal member 9 Boundary portion between member 5 and member 6 10 Boundary portion between member 5 and member 7 11 Hollow member 12 Flange member 13 Silver or silver alloy 14 Boundary portion between hollow member 11 and flange member 15 Middle core member 16 Another member 17 Member having peripheral concave portion 18 Member having convex portion to be engaged with member 17 19 Silver or silver alloy 20 Boundary portion between member 17 and member 18 21 Hollow member 22 Flange member 23 Silver or silver alloy 24 Boundary portion between hollow member 21 and flange member 22 25 Core member 2 Stacking plate 27 Silver or silver alloy 28 Boundary portion between flange member 22 and collecting plate 26 29 Oxygen separation container 30 Silver or silver alloy 31 Boundary portion between collecting plate 26 and oxygen separation container 29 32 One region isolated by composite 33 Another area isolated by the complex 34 Air inlet 35 Oxygen-poor air outlet 36 Separation / recovery oxygen 37 Hollow member 38 Flange member 39 Silver or silver alloy 40 Boundary part 41 between hollow member 37 and flange member 41 41 Core Member 42 Stacking plate 43 Silver or silver alloy 44 Boundary part between flange member 38 and collecting plate 42 45 Diaphragm reactor vessel 46 Silver or silver alloy 47 Boundary part between collecting plate 42 and diaphragm reactor vessel 45 48 One separated by the complex Area 49 another area isolated by the complex 50 natural gas inlet 51 syngas outlet 52 air channel Mouth 53 oxygen Hinka air outlet

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor, etc. 20-1 Shintomi, Futtsu-shi Nippon Steel Corporation Technology Development Division (72) Inventor Toru Nagai 20-1 Shintomi, Futtsu-shi Nippon Steel Corporation 4D006 GA41 HA21 JA22C JA22Z JB01 MA02 MB04 MC02X MC03X PB62 PB66 PB67 PC69 PC71 4G042 BA28 BC06 5H026 AA06 EE02 EE12 HH00 HH08

Claims (12)

[Claims] 1. A composite comprising a structure having a storage portion formed by combining a plurality of members, and a metal member, wherein the metal member is filled in the storage portion and constitutes the structure. A composite having sealability, characterized in that a part or the entirety of a combination boundary of the members is filled with the metal member. 2. The composite having sealability according to claim 1, wherein the softening temperature of the metal member is lower than the softening temperature of the members constituting the structure. 3. The composite according to claim 2, wherein the metal member is silver or a silver alloy. 4. The structure according to claim 1, wherein each of the members forming the structure is made of ceramic or metal, and the structure is formed of ceramics, metals, or a combination of ceramic and metal. A composite having a sealing property according to item 1. 5. The member constituting the structure has an average linear thermal expansion coefficient from room temperature to 850 ° C. of 16 × 10 ⁻⁶ / ° C. or more.
The composite having sealability according to claim 4, which is at most ^{6 10-6} / C. 6. The sealing property according to claim 1, wherein a part of the member constituting the structure is an oxide material having an oxide ion permeability. A composite having: 7. A composite of a structure comprising at least a hollow member having an oxide ion-permeable oxide layer, one end of which is sealed, and a flange member, and silver or a silver alloy, The structure has a storage portion formed by combining the open end of the hollow member and the flange member, and has a sealing property characterized by being filled with the silver or silver alloy in the storage portion. Complex. 8. A composite formed by combining a member having a circumferential concave portion and a member having a convex portion insertable into the concave portion, wherein each of the members is at least one selected from a metal and a ceramic. And a storage part formed by inserting the convex part into the concave part and filling the storage part with silver or a silver alloy. 9. A step of forming a structure having a storage portion by combining a plurality of members, and at least one kind selected from a metal member or a metalized member softened at a lower temperature than the members constituting the structure. A step of inserting a metal material into the storage section, and heating at least the storage section to a temperature range equal to or higher than the softening temperature of the metal material inserted into the storage section and lower than the softening temperature of the member constituting the structure. Curing the metal material while filling at least one of the combination boundary portions of the storage portion and the members constituting the structure with the metal material. Manufacturing method. 10. The metal material inserted into the storage part is one selected from silver, a silver alloy, a clay containing silver, a clay containing a silver alloy, a slurry containing silver, and a slurry containing a silver alloy. The method for producing a composite having sealability according to claim 9, wherein: 11. An oxygen separator comprising the composite having a sealing property according to claim 1. Description: 12. A diaphragm reactor comprising the composite having a sealing property according to any one of claims 1 to 8.