JP2020135925A - Manufacturing method of cylindrical workpiece - Google Patents

Abstract

To efficiently manufacture multiple cylindrical work-pieces by collectively reducing inner peripheral sides of multiple cylindrical precursors.SOLUTION: Multiple cylindrical precursors which are precursors of cylindrical bodies are prepared. A box-shaped gas supply body in which a space is formed is prepared. The gas supply body comprises: a first wall on which multiple exhaust holes communicating to the space are formed; a second wall which is disposed while facing the first wall with the space interposed in a first direction and on which one introduction hole communicating to the space is formed; and a sidewall connecting a circumference of the first wall and a circumference of the second wall. Next, each of the exhaust holes formed on the first wall of the gas supply body and an inner peripheral side of each of the multiple cylindrical precursors are individually coupled, and a reduction gas is introduced to the introduction hole which is formed on the second wall of the gas supply body.SELECTED DRAWING: Figure 5

Description

The techniques disclosed herein relate to methods of manufacturing tubular workpieces.

As a tubular work having a tubular body in which a through hole is formed, a tubular modified structure including an oxygen permeable layer is known (see, for example, Patent Document 1). The reformed structure produces a reformed gas containing carbon monoxide and hydrogen from a fuel gas containing a hydrocarbon (for example, methane). The reformed structure is a technique for producing a liquid hydrocarbon fuel (GTL (Gas to Liquid), for example, in order to obtain hydrogen to be supplied to a fuel cell, or by further converting hydrogen and carbon monoxide into hydrocarbons. Used for (called).

Specifically, the reformed structure includes an oxygen permeable layer and a reformed catalyst layer. The oxygen permeable layer has oxide ion conductivity and electron conductivity or hole conductivity, and is located in the inner peripheral space located on the inner peripheral side of the modified structure and on the outer peripheral side of the modified structure. It is a layer that allows oxygen ions to permeate between the outer peripheral side space and the inner peripheral side space of the modified structure by using the oxygen partial pressure difference with the located outer peripheral side space as a driving force. The reforming catalyst layer is, for example, a layer that is arranged on the inner peripheral side space side with respect to the oxygen permeable layer and contains a catalyst that promotes the partial oxidation reforming reaction. In the reformed structure including the oxygen permeable layer, for example, air is supplied to the outer peripheral side space along the axial direction of the reformed structure, and the fuel gas containing hydrocarbons is contained in the inner peripheral side space along the axial direction. Is supplied, oxygen in the air supplied to the outer peripheral space permeates the oxygen permeable layer and enters the inner peripheral space, and a partial oxidation reforming reaction between hydrocarbons and oxygen occurs in the inner peripheral space. , This reforms the hydrocarbon. In addition, the reforming catalyst layer promotes the partial oxidation reforming reaction.

Japanese Patent Application No. 2018-2558

In the method for producing a tubular modified structure provided with the oxygen permeable layer, a reducing gas is introduced into the through hole of the tubular precursor before the inner peripheral side of the modified structure is reduced, and the tubular precursor is introduced. It includes the step of reducing the inner circumference of the body. Conventionally, when manufacturing a plurality of reformed structures, one gas supply source is connected to the through hole of one tubular precursor, and the inner peripheral side of the tubular precursor is reduced one by one. It was. Therefore, there is a problem that a plurality of modified structures cannot be efficiently produced.

It should be noted that such a problem is not limited to the tubular modified structure including the oxygen permeable layer, but is also a common problem when manufacturing a plurality of tubular workpieces having a tubular body having through holes formed therein. is there.

This specification discloses a technique capable of solving the above-mentioned problems.

The techniques disclosed herein can be realized, for example, in the following forms.

(1) The method for manufacturing a tubular work disclosed in the present specification is a method for manufacturing a tubular work having a tubular body having through holes, and is a tubular precursor which is a precursor of the tubular body. The first preparatory step of preparing a plurality of these, and the first wall of a box-shaped gas supply body having a space formed inside and having a plurality of discharge holes communicating with the space. A second wall, which is arranged to face the first wall through the space in the first direction and has one introduction hole communicating with the space, a peripheral edge of the first wall, and the above. A second preparatory step for preparing a gas supply body having a side wall connecting the peripheral edges of the second wall, and each of the plurality of discharge holes formed in the first wall of the gas supply body. A connecting step of individually connecting the inner peripheral sides of the plurality of tubular precursors, and after the connecting step, a reducing gas is applied to the introduction hole formed in the second wall of the gas supply body. By introducing the mixture, the process comprises a reduction step of reducing the inner peripheral side of the plurality of tubular precursors to form the plurality of tubular precursors.

In the method for manufacturing the tubular work, each of the plurality of discharge holes formed in the first wall of the gas supply body and the inner peripheral side of each of the plurality of tubular precursors are individually connected. After that, the reducing gas is introduced into one introduction hole formed in the second wall of the gas supply body. As a result, the inner peripheral side of the plurality of tubular precursors is reduced, and a plurality of tubular workpieces are formed. As a result, according to the method for manufacturing this tubular work, the inner peripheral side of a plurality of tubular precursors can be collectively reduced by using one gas feeder, so that a plurality of tubular workpieces can be efficiently produced. Can be manufactured.

(2) In the method for manufacturing a tubular work, at least a part of the plurality of discharge holes is located outside the outer shape of the introduction hole in the first directional view, and the gas supply body further comprises. It may be configured to include an opposing body arranged in the space of the gas supply body and partially facing the introduction hole.

In the method for manufacturing the tubular work, at least a part of the plurality of discharge holes is located outside the outer shape of the introduction hole in the first directional view. In such a configuration, there is a possibility that the discharge flow rate of the reducing gas per unit time (hereinafter, referred to as “reduction gas discharge flow rate”) varies in the plurality of discharge holes. That is, from the discharge flow rate of the reducing gas from the discharge hole formed in the peripheral portion of the first wall facing the position facing the introduction hole and the discharge hole formed in the outer portion located further outside the peripheral portion. There may be a difference in the discharge flow rate of the reducing gas from the above, and as a result, the discharge flow rate of the reducing gas from each of the plurality of discharge holes may vary. However, in the method for manufacturing this tubular work, the space of the gas supply body is provided with an opposing body whose part faces the introduction hole. As a result, most of the reducing gas introduced into the space of the gas supply body from the introduction hole spreads in the space after hitting the opposing body, and then is discharged from the plurality of discharge holes. For this reason, the reduced gas introduced into the space of the gas supply body from the introduction hole directly hits the first wall, so that the discharge flow rate of the reduced gas from each of the plurality of discharge holes varies. It can be suppressed. As a result, it is possible to efficiently manufacture a plurality of tubular workpieces while suppressing variations in the degree of reduction on the inner peripheral side of the plurality of tubular precursors.

(3) In the method for manufacturing a tubular work, the facing body is a first portion of the first wall in which at least all of the plurality of discharge holes are formed in the space of the gas supply body. The first space facing the surface and the second space facing at least the second portion of the second wall on which the introduction hole is formed are arranged so as to be partitioned from the first space. It may be configured as a porous body in which a plurality of communication holes communicating from the surface on the space side of 1 to the surface on the second space side are formed.

In the method for manufacturing the tubular workpiece, the opposing body has the space of the gas supply body as at least one of the first space facing at least the first portion of the first wall and the second wall. It is arranged so as to partition into a second space facing the second portion where the introduction hole is formed. Further, the opposing body is a porous body in which a plurality of communication holes communicating from the surface on the first space side to the surface on the second space side are formed. As a result, the reducing gas introduced into the space of the gas supply body from the introduction hole passes through the plurality of communication holes of the opposing body, so that the difference in the discharge flow rate of the reducing gas is reduced, and then the reduced gas is discharged from the plurality of discharge holes. Will be done. As a result, it is possible to suppress variations in the discharge flow rate of the reducing gas in the plurality of discharge holes.

(4) In the method for manufacturing a tubular work, a hole which is a ratio of the total area of the plurality of communication holes to the outer area of the facing body in at least one cross section orthogonal to the thickness direction of the facing body. The area ratio may be 20% or less. According to the method for manufacturing the tubular work, it is possible to more effectively suppress the variation in the discharge flow rate of the reducing gas in the plurality of discharge holes as compared with the case where the hole area ratio of the facing body is higher than 20%. ..

(5) In the method for manufacturing a tubular work, the hole area ratio of the plurality of communication holes may be 5% or more. According to the method for manufacturing the tubular work, it is possible to suppress an increase in the pressure in the space of the gas supply body due to the presence of the porous body as compared with the case where the pore area ratio of the porous body is lower than 5%.

(6) In the method for manufacturing a tubular work, the thickness of the facing body may be 1 mm or more. According to the method for manufacturing the tubular work, the thickness of the facing body can more effectively suppress the variation in the discharge flow rate of the reducing gas in the plurality of discharge holes as compared with the case where the thickness of the facing body is thinner than 1 mm.

It is explanatory drawing which shows the structure of the oxygen permeable membrane structure 100 of this embodiment. It is explanatory drawing which shows the detailed structure of an oxygen permeable membrane structure 100. It is a flowchart which shows an example of the manufacturing method of an oxygen permeable membrane structure 100. It is a perspective view which shows the state which disassembled the gas supply body 200. It is explanatory drawing which shows the XZ cross-sectional structure of the gas supply body 200. It is explanatory drawing which shows typically the flow of the reduction gas RG in the space R of the 1st gas supply body 200A. It is explanatory drawing which shows typically the flow of the reduction gas RG in the space R of the 2nd gas supply body 200B. The variation (%) of the discharge flow rate of the reducing gas RG, the hole area ratio (%) of the communication hole 310, the thickness (mm) of the perforated plate 300, and the introduction flow rate (m / s) from the introduction hole 222. It is explanatory drawing which shows the relationship.

A. Embodiment:
A-1. Composition of oxygen permeable membrane structure 100:
1 and 2 are explanatory views showing the configuration of the oxygen permeable membrane structure 100 of the present embodiment. FIG. 1 shows the XY cross-sectional structure of the oxygen permeable membrane structure 100, and FIG. 2 shows a part of the YZ cross-sectional structure of the oxygen permeable membrane structure 100 at the position II-II of FIG. ing. 1 and 2 show XYZ axes that are orthogonal to each other to identify the direction. In the present specification, for convenience, the Z-axis positive direction is referred to as an upward direction, and the Z-axis negative direction is referred to as a downward direction. The same applies to FIGS. 3 and later. The oxygen permeable membrane structure 100 corresponds to a tubular work in the claims, and the vertical direction (Z-axis direction) corresponds to the first direction in the claims.

The oxygen permeable membrane structure 100 is a substantially cylindrical member in which a through hole 110 is formed. The space outside the oxygen permeable membrane structure 100 constitutes the air chamber S1, and the space inside the oxygen permeable membrane structure 100 constitutes the fuel chamber S2. As shown in FIGS. 1 and 2, the oxygen permeable membrane structure 100 includes a support 114, a modified catalyst layer (also referred to as “fuel electrode”) 112, an oxygen permeable membrane 111, and an oxygen dissociation catalyst layer (air). It is composed of 113 (also called a pole). The support 114 is arranged on the innermost peripheral side (the side facing the fuel chamber S2) of the oxygen permeable membrane structure 100, and is modified in order from there toward the outer peripheral side (the side facing the air chamber S1). The quality catalyst layer 112, the oxygen permeation membrane 111, and the oxygen dissociation catalyst layer 113 are laminated adjacent to each other.

The support 114 is a porous substantially cylindrical member, and supports other layers (modified catalyst layer 112, oxygen permeable membrane 111, oxygen dissociation catalyst layer 113) constituting the oxygen permeable membrane 111. The support 114 is formed of, for example, stabilized zirconia or the like. In particular, the support 114 is partially stabilized zirconia and stabilized zirconia (ScSZ, YSZ, CSZ, etc.) is formed of a material containing at least one kind of the magnesium oxide (MgO) and spinel (MgAl ₂ O ₄₎ It is preferable to have. As a result, the chemical stability is high, and the occurrence of mechanical cracks due to the difference in the coefficient of thermal expansion between the support 114 and the oxygen permeable membrane 111 can be suppressed. Further, when the oxygen permeable membrane 111 contains lantern chromite and the support 114 contains partially stabilized zirconia or stabilized zirconia, the reaction between the forming material of the oxygen permeable membrane 111 and the forming material of the support 114 is suppressed, and oxygen is suppressed. The durability of the permeable membrane structure 100 can be increased.

The oxygen dissociation catalyst layer 113 is a porous substantially cylindrical member, and serves as a catalyst layer that promotes a reaction (1 / 2O ₂ + 2e ⁻ → O ^2- ) for ionizing oxygen in the air supplied to the air chamber S1. Function. The oxygen dissociation catalyst layer 113 is formed of, for example, a composite oxide such as La _0.8 Sr _0.2 MnO ₃ or La _0.8 Sr _0.2 CrO ₃ .

The oxygen permeable membrane 111 is a gas-impermeable, substantially cylindrical membrane having oxide ion conductivity and electron conductivity or hole conductivity. In the following description, electron conductivity and hole conductivity are collectively referred to as electrical conductivity. The oxygen permeable film 111 uses the oxygen partial pressure difference between the air chamber S1 and the fuel chamber S2 separated by the oxygen permeable film 111 as a driving force to drive the air chamber S1 on the high oxygen partial pressure side to the fuel chamber S2 on the low oxygen partial pressure side. Selectively permeates oxygen into. The oxygen permeable membrane 111 is made of, for example, a mixture of a substance having oxide ion conductivity (hereinafter referred to as “oxide ion conductor”) and a substance having electrical conductivity (hereinafter referred to as “electric conductor”). It is formed. The oxygen permeable membrane 111 may be formed of a substance having both oxide ion conductivity and electrical conductivity (hereinafter, referred to as “mixed conductor”). Further, the oxygen permeable membrane 111 may be formed by a mixture of at least one of an oxide ion conductor and an electric conductor and a mixed conductor.

As the oxide ion conductor, for example, stabilized zirconia, partially stabilized zirconia, a ceria-based solid solution, or the like can be used. As the electric conductor, for example, an oxide having a perovskite structure, a ferrite having a spinel-type crystal structure, a metal material such as a noble metal, or the like can be used. Mixing The conductor additive, for example, in LaGaO ₃ type compounds, LSGF based oxide having a perovskite structure with the addition of Fe to the Ga site with the addition of Sr to La sites, the SrCoO ₃ based compound, a Ba to Sr site BSCF-based oxides having a perovskite structure, oxides having a layered perovskite structure, oxides having a fluorite-type structure, oxides having an oxyapatite structure, oxides having a merylite structure, etc. Can be used.

The reforming catalyst layer 112 is a porous substantially cylindrical member, and contains hydrocarbons in the fuel gas FG supplied from the fuel chamber S2 through the support 114 which is the porous member, and the oxygen permeable film 111. the transmitted partial oxidation reforming reaction with getting the oxygen (oxide ^{_{ions) (C n H m + nO}} 2- → nCO + (m / 2) H 2 + 2ne -) functions as a catalyst layer to promote. Reforming catalyst layer 112 is, for example, a LaCrO ₃ type oxide having a perovskite structure, with the addition of Sr to La site, is formed of a composite oxide or the like is added to the Cr site Ni.

A-2. Operation of oxygen permeable membrane structure 100:
When air is supplied to the air chamber S1, a reaction (1 / 2O ₂ + 2e ⁻ → O ^2- ) that ionizes oxygen in the air occurs due to the catalytic effect of the oxygen dissociation catalyst layer 113 facing the air chamber S1. The oxide ions generated by this reaction move to the fuel chamber S2 side in the oxygen permeable membrane 111 having oxide ion conductivity (see FIG. 3).

Further, when the fuel gas FG is supplied to the fuel chamber S2, the fuel gas FG passes through the inside of the support 114 which is a porous member and reaches the reforming catalyst layer 112, and due to the catalytic effect of the reforming catalyst layer 112, partial oxidation reforming reaction with oxygen that has passed through the hydrocarbon and oxygen-permeable membrane 111 of the fuel gas FG (oxide ^{_{ions) (C n H m + nO}} 2- → nCO + (m / 2) H 2 + 2ne -) is Occur. By this reaction, the fuel gas FG containing hydrocarbons is reformed into hydrogen and carbon monoxide. The electrons generated by the partial oxidation reforming reaction move to the air chamber S1 side in the oxygen permeable membrane 111 having electrical conductivity, and are subjected to the above-mentioned oxygen ionization reaction (see FIG. 3).

A-3. Method for manufacturing oxygen permeable membrane structure 100:
Next, an example of the method for producing the oxygen permeable membrane structure 100 in the present embodiment will be described. FIG. 3 is a flowchart showing an example of a method for manufacturing the oxygen permeable membrane structure 100.

(First preparation process)
As shown in FIG. 3, first, a plurality of tubular precursors 100P (preferably 5 or more) are prepared (S110). The tubular precursor 100P is a precursor of the oxygen permeable membrane structure 100 which becomes the oxygen permeable membrane structure 100 by the reduction treatment. Specifically, the tubular precursor 100P is different from the oxygen permeable membrane structure 100 in that the reformed catalyst layer precursor 112P is provided instead of the reformed catalyst layer 112. The reformed catalyst layer precursor 112P contains nickel oxide (NiO) before the Ni contained in the reformed catalyst layer 112 is reduced. The tubular precursor 100P is produced, for example, by the following method.

To the calcium-stabilized zirconia (CSZ) powder, add a cellulosic binder and polymethylmethacrylate (PMMA) bead powder as a pore-forming material, mix well, and add water to make clay. Mixed up to. The amount of the pore-forming material added was set so that 60 (vol%) was pores with respect to the volume of the CSZ powder. The clay-like mixture was put into an extrusion molding machine to prepare a cylindrical support molded body having an outer diameter of 12 mm.

Next, La _0.8 Sr _0.2 Cr _0.85 Ni _0.15 O _3-z was prepared as a material for forming the reformed catalyst layer. As raw materials, powders of lanthanum oxide (La ₂ O ₃ ), strontium carbonate (SrCO ₃ ), chromium oxide (Cr ₂ O ₃ ), and nickel oxide (NiO) were used. These raw material powders were weighed so that the ratio of metal elements was the ratio of the above composition formula. In addition, z in the composition formula is an oxygen non-stoichiometric ratio representing the amount of oxygen deficiency (the same applies hereinafter). Ethanol was added to these raw material powders, and wet mixing and pulverization was carried out using ceramic balls and a resin pot for 15 hours. Then, it was dried in hot water to remove ethanol, and the obtained mixed powder was calcined at 1500 ° C. for 24 hours to obtain La _0.8 Sr _0.2 Cr _0.85 Ni _0.15 O, which is a calcined powder. _{A 3-z} powder was obtained. The obtained La _0.8 Sr _0.2 Cr _0.85 Ni _0.15 O _3-z powder and a commercially available ScSZ (Sc _0.1 Ce _0.01 Zr _0.89 O ₂ ) powder were used. Weighed so that the volume ratio was 50:50, polyvinyl butyral, an amine-based dispersant, and a plasticizer were mixed with methyl ethyl ketone and ethanol as solvents to prepare a coating slurry for forming a modified catalyst layer. ..

Further, in order to form an oxygen permeable membrane, a mixed powder of ScSZ and La _0.8 Sr0.2CrO _3-z , polyvinyl butyral, an amine-based dispersant, and a plasticizer are used as solvents, and methyl ethyl ketone and ethanol are used as solvents. The mixture was mixed to prepare a coating slurry for forming an oxygen permeable membrane.

Next, the above-mentioned molded body for a support was cut to a predetermined length, masked at a position where the reformed catalyst layer was not formed, and then immersed in the above-mentioned slurry for coating for forming a reformed catalyst layer. After that, the reformed catalyst layer unfired body was formed on the surface of the support molded body by slowly pulling it up. Further, after masking the position where the oxygen permeable film is not formed, the film is immersed in the oxygen permeable film forming coating slurry, and then slowly pulled up to modify the surface of the support molded body. An oxygen permeable membrane unfired body was formed on the surface of the catalyst layer unfired body. Then, at 1500 ° C., the modified catalyst layer 112, the oxygen permeable film 111, and the support 114 are formed by simultaneously firing the molded body for the support, the unfired body of the modified catalyst layer, and the unfired body of the oxygen permeable film. A tubular sintered body comprising the above was obtained.

Further, in order to form an oxygen dissociation catalyst layer, a commercially available La _0.8 Sr _0.2 MnO ₃ powder and a commercially available ScSZ (Sc _0.1 Ce _0.01 Zr _0.89 O ₂ ) powder are mixed in a volume ratio. The powder mixed so as to be 70:30, polyvinyl butyral, an amine-based dispersant, and a plasticizer were mixed with methyl ethyl ketone and ethanol as solvents to prepare a slurry for forming an oxygen dissociation catalyst layer. The above-mentioned tubular sintered body is masked at a position where the oxygen dissociation catalyst layer is not formed, immersed in the slurry for forming the oxygen dissociation catalyst layer, and then slowly pulled up to unfire the oxygen dissociation catalyst layer. Formed a body. Then, the oxygen dissociation catalyst layer 113 was prepared by performing a baking treatment at 1300 ° C. By the above method, a tubular precursor 100P (see FIG. 5 described later) including the support 114, the reformed catalyst layer precursor 112P, the oxygen permeable membrane 111, and the oxygen dissociation catalyst layer 113 was produced. The tubular precursor 100P is a tubular body having one through hole extending in the longitudinal direction, like the oxygen permeable membrane structure 100. Further, regarding the tubular precursor 100P, for example, the axial length is 1200 mm or more and 2000 mm or less, the outer diameter is 6 mm or more and 25 mm or less, the inner diameter is 5 mm or more and 20 mm or less, and the wall thickness is 1 mm. It is 5 mm or less.

As in the production method of the present embodiment, first, a modified catalyst layer unfired body is formed using a material containing NiO as a reformed catalyst layer constituent material, and the reformed catalyst layer unfired body is fired. A tubular precursor 100P is produced. Then, as described below, it is preferable to prepare the oxygen permeable membrane structure 100 by introducing the reducing gas RG on the inner peripheral side of the tubular precursor 100P. However, the reducing gas RG is not introduced on the outer peripheral side of the tubular precursor 100P. An oxygen dissociation catalyst layer 113 is arranged on the outer peripheral side of the tubular precursor 100P, and if a reducing gas RG is introduced on the outer peripheral side of the tubular precursor 100P, the material forming the oxygen dissociation catalyst layer 113 is reduced. As a result, the performance of the oxygen permeable membrane structure 100 may deteriorate.

In the manufacturing method of the present embodiment, the reduction gas RG is introduced only on the inner peripheral side (inside the through hole 110) of the plurality of tubular precursors 100P, and the reduction on the inner peripheral side of the plurality of tubular precursors 100P is performed. Are done together. The details will be described below.

(Second preparation process)
As shown in FIG. 3, the gas supply body 200 is prepared (S120). FIG. 4 is a perspective view showing a state in which the gas supply body 200 is disassembled, and FIG. 5 is an explanatory view showing an XZ cross-sectional configuration of the gas supply body 200. FIG. 5 shows a plurality of tubular precursors 100P connected to the gas supply body 200. Further, FIG. 5 shows an enlarged XZ cross-sectional structure of the X1 portion of the tubular precursor 100P and one tubular precursor 100P.

The gas supply body 200 is a box-shaped body having a space R formed inside. Specifically, as shown in FIG. 4, the gas supply body 200 includes a first lid portion 201, a second lid portion 202, and a perforated plate 300.

The first lid 201 has a box shape with an open upper side, and specifically, a first side wall 232 having a substantially rectangular frame shape in the vertical direction (Z-axis direction) and a vertical view. A bottom wall 210 having a substantially rectangular flat plate shape is provided. The bottom wall 210 is arranged so as to close the entire lower end side of the first side wall 232. Further, a plurality of discharge holes 212 are formed in the bottom wall 210. Each discharge hole 212 penetrates the bottom wall 210 in the vertical direction (see also FIG. 5). The plurality of discharge holes 212 are arranged at equal intervals in two directions (X direction and Y direction in FIG. 4) in which the diameters of the holes are substantially the same and are orthogonal to each other in the vertical direction. ing.

The second lid portion 202 has a box shape with an opening on the lower side, and specifically, a second side wall 234 having a substantially rectangular frame shape in the vertical direction (Z-axis direction) view and a vertical view view. A ceiling wall 220 having a substantially rectangular flat plate shape is provided. The ceiling wall 220 is arranged so as to close the entire upper end side of the second side wall 234. Further, when viewed in the vertical direction, one introduction hole 222 is formed substantially in the center of the ceiling wall 220. The introduction hole 222 penetrates the ceiling wall 220 in the vertical direction (see also FIG. 5). The diameter of the introduction hole 222 is larger than the diameter of each discharge hole 212 formed in the bottom wall 210.

The perforated plate 300 is a flat plate-like member having a substantially rectangular shape in the vertical direction (Z-axis direction). A plurality of communication holes 310 are formed in the perforated plate 300. However, in FIG. 5, the communication hole 310 is omitted. Each communication hole 310 communicates from the upper surface S3 of the perforated plate 300 to the lower surface S4 of the perforated plate 300. The plurality of communication holes 310 are arranged at equal intervals in two directions (X direction and Y direction in FIG. 4) in which the diameters of the holes are substantially the same and are orthogonal to each other in the vertical direction. ing. Further, the diameter of each communication hole 310 is smaller than the diameter of each discharge hole 212 formed in the bottom wall 210. Further, the number of communication holes 310 formed in the perforated plate 300 is larger than the number of discharge holes 212 formed in the bottom wall 210. Further, the arrangement interval between the communication holes 310 in the perforated plate 300 is preferably narrower than the arrangement interval of the discharge holes 212 in the bottom wall 210.

The perforated plate 300 is arranged so as to be sandwiched between the bottom wall 210 and the ceiling wall 220 at the top and bottom. The perforated plate 300 closes the entire upper end side of the first lid portion 201 and also closes the entire lower end side of the second lid portion 202. The perforated plate 300 corresponds to an opposing body or a perforated body within the scope of claims.

With the above configuration, the bottom wall 210 of the first lid portion 201 constitutes the bottom wall of the gas supply body 200, and the ceiling wall 220 of the second lid portion 202 constitutes the ceiling wall of the gas supply body 200. .. Further, the first side wall 232 of the bottom wall 210, the second side wall 234 of the ceiling wall 220, and the outer peripheral surface 236 of the perforated plate 300 form a peripheral edge of the bottom wall and a peripheral edge of the ceiling wall in the gas supply body 200. The side wall 230 to be connected is formed. The side wall of the gas supply body 200 is not formed with an introduction hole and a discharge hole. The bottom wall 210 corresponds to the first wall in the claims. Further, the ceiling wall 220 arranged so as to face the bottom wall 210 through the space R in the vertical direction (Z-axis direction) corresponds to the second wall in the claims. Further, the side wall 230 of the gas supply body 200 corresponds to the side wall in the claims.

Further, as described above, a part of the perforated plate 300 faces the introduction hole 222 of the ceiling wall 220. In other words, a part of the perforated plate 300 is located within the outer shape (contour line) of the introduction hole 222 in the vertical direction (Z-axis direction). Further, when viewed in the vertical direction (Z-axis direction), at least a part of the plurality of discharge holes 212 is located outside the outer shape (contour line) of the introduction hole 222.

Further, as shown in FIG. 5, the perforated plate 300 is arranged so as to partition the space R of the gas supply body 200 into a first space R1 and a second space R2. The first space R1 is a space facing the bottom wall 210 in which the discharge hole 212 is formed, and specifically, is a space formed by the first lid portion 201 and the perforated plate 300. The second space R2 is a space facing the ceiling wall 220 in which the introduction hole 222 is formed, and specifically, is a space formed by the second lid portion 202 and the perforated plate 300. Further, in the present embodiment, the bottom wall 210 and the ceiling wall 220 are substantially parallel to each other, and the perforated plate 300 is arranged so as to be substantially parallel to both the bottom wall 210 and the ceiling wall 220. Further, the perforated plate 300 is arranged at a position substantially in the vertical direction (Z-axis direction) (equidistant distance from both the bottom wall 210 and the ceiling wall 220) in the space R of the perforated plate 300. As a result, the pressure loss in the second space R2 becomes high due to the short distance between the introduction hole 222 and the perforated plate 300, and the reducing gas RG introduced from the introduction hole 222 becomes difficult to spread in the plane direction. Can be suppressed.

Further, in at least one XY plane orthogonal to the thickness direction (vertical direction) of the perforated plate 300, the area of the perforated plate 300 (in the perforated plate 300, the first space R1 or the second space R1 in the state of the gas supply body 200). The area exposed to the space R2, in other words, the area excluding the portion overlapping the first side wall 232 of the first lid portion 201 or the second side wall 234 of the second lid portion 202 in the vertical direction). The hole area ratio, which is the total ratio of the areas of all the communication holes 310, is 20% or less. Further, the pore area ratio is more preferably 5% or more. The thickness direction is a direction orthogonal to the perforated plate 300.

Further, the thickness (vertical dimension) of the perforated plate 300 is preferably 1 mm or more.

(Connecting process)
Next, as shown in FIGS. 3 and 5, each of the plurality of discharge holes 212 formed in the bottom wall 210 of the gas supply body 200 and the inner peripheral side of each of the plurality of tubular precursors 100P. , Are individually connected (S130). Specifically, a tubular connecting portion 214 communicating with each discharge hole 212 is formed on the lower surface of the bottom wall 210 so as to project, and the tip of the connecting portion 214 is formed from the connecting portion 214. A tubular joint portion 215 having a large diameter is provided. By press-fitting the upper end portion of each tubular precursor 100P into the joint portion 215, each discharge hole 212 and the inner peripheral side of each tubular precursor 100P are connected.

(Reduction process)
As shown in FIG. 3, by introducing the reducing gas RG into the introduction hole 222 formed in the gas supply body 200 after the connecting step, the inner peripheral side (reform catalyst layer precursor) of a plurality of tubular precursors 100P is introduced. The body 112P) is reduced to form a plurality of oxygen permeable membrane structures 100 (S140). Specifically, the gas supply body 200 and a plurality of tubular precursors 100P connected to the gas supply body 200 are arranged in a furnace (not shown), and the reducing gas RG is gas while being heated by the furnace. It is introduced from the introduction hole 222 formed in the ceiling wall 220 of the feeder 200. The reduced gas RG introduced into the introduction hole 222 flows into the second space R2 of the gas supply body 200, flows into the first space R1 through the plurality of communication holes 310 formed in the perforated plate 300, and supplies the gas. It is discharged from each of the plurality of discharge holes 212 formed in the bottom wall 210 of the body 200. The reducing gas RG discharged from each discharge hole 212 is introduced into the through hole 110 of each tubular precursor 100P via the connecting portion 214. When the introduced reducing gas RG reaches the reformed catalyst layer precursor 112P via the support 114, NiO contained in the reformed catalyst layer 112 is reduced to form the reformed catalyst layer 112. As described above, the production of a plurality of oxygen permeable membrane structures 100 is completed.

A-4. Effect of this embodiment:
As described above, in the method for producing the oxygen permeable membrane structure 100 of the present embodiment, each of the plurality of discharge holes 212 formed in the bottom wall 210 of the gas supply body 200 and the plurality of tubular precursors 100P Is individually connected to each of the inner peripheral sides of the gas (S130 in FIG. 3), and then the reduced gas RG is introduced into one introduction hole 222 formed in the ceiling wall 220 of the gas supply body 200 (FIG. 3). S140). As a result, the inner peripheral side of the plurality of tubular precursors 100P is reduced, and a plurality of oxygen permeable membrane structures 100 are formed. As a result, according to the present embodiment, the inner peripheral side of the plurality of tubular precursors 100P can be reduced together by using one gas supply body 200, so that the plurality of oxygen permeable membrane structures 100 can be efficiently reduced. Can be manufactured well.

Further, according to the present embodiment, a part of the perforated plate 300 faces the introduction hole 222 of the ceiling wall 220. Further, when viewed in the vertical direction (Z-axis direction), at least a part of the plurality of discharge holes 212 is located outside the outer shape (contour line) of the introduction hole 222. As a result, most of the reducing gas RG introduced into the space R of the gas supply body 200 from the introduction hole 222 spreads to the second space R2 after hitting the perforated plate 300, and then is discharged from the plurality of discharge holes 212. As a result, the reduced gas RG introduced into the space R of the gas supply body 200 from the introduction hole 222 directly hits the bottom wall 210, so that the discharge flow rate of the reduced gas RG per unit time in each discharge hole 212 ( It is possible to suppress the occurrence of variation in g / s) (hereinafter referred to as “reduced gas RG discharge flow rate”).

Further, in the present embodiment, the perforated plate 300 is arranged so as to partition the space R of the gas supply body 200 into the first space R1 and the second space R2. Further, the perforated plate 300 is a porous body in which a plurality of communication holes 310 communicating with each other from the upper surface S3 to the lower surface S4 of the perforated plate 300 are formed. As a result, the reducing gas RG introduced from the introduction hole 222 into the space R of the gas supply body 200 passes through the plurality of communication holes 310 of the perforated plate 300, thereby reducing the difference in flow velocity, and then the plurality of discharge holes. It is discharged from 212. As a result, it is possible to suppress variations in the discharge flow rate of the reducing gas RG in the plurality of discharge holes 212. Hereinafter, a specific description will be given.

FIG. 6 is an explanatory diagram schematically showing the flow of the reducing gas RG in the space R of the first gas supply body 200A, and FIG. 7 is an explanatory diagram showing the flow of the reducing gas RG in the space R of the second gas supply body 200B. It is explanatory drawing which shows the flow of. The plurality of arrows shown in the gas feeders 200A and 200B in FIGS. 6A and 7 indicate the flow of the reducing gas RG, and the higher the density of the arrows, the more the discharge flow rate of the reducing gas RG ( It means that there is a lot of g / s). In FIG. 6A, the discharge hole 212 is omitted. In FIGS. 6A and 7, the inflow velocity of the reducing gas RG in the introduction hole 222 is 10 m / s, and in FIG. 7, the thickness of the perforated plate 300 is 10 mm. Further, FIG. 6B shows the discharge flow rate of the reducing gas RG of the plurality of discharge holes 212 formed in the bottom wall 210. The numerical values on the horizontal axis of FIG. 6B indicate the positions of the plurality of discharge holes 212. The plurality of discharge holes 212 referred to here are 18 discharge holes 212 belonging to two rows located at the center of the bottom wall 210 in the Y-axis direction.

As shown in FIG. 6, the first gas supply body 200A differs from the gas supply body 200 described above (see FIGS. 4 and 5) in that it does not have the perforated plate 300, and is the same in other respects. Is. That is, in the space R of the first gas supply body 200A, there is no object facing the introduction hole 222 between the ceiling wall 220 and the bottom wall 210. Here, in the first gas supply body 200A, similarly to the gas supply body 200, one introduction hole 222 is formed in the ceiling wall 220, and a plurality of discharge holes 212 are formed in the bottom wall 210. Therefore, it is possible to reduce the inner peripheral side of a plurality of tubular precursors 100P together by using one first gas supply body 200A.

However, the first gas supply body 200A does not include the perforated plate 300. Therefore, in the first gas supply body 200A, the reduced gas RG introduced into the space R of the gas supply body 200 from the introduction hole 222 directly hits the bottom wall 210. Therefore, although a part of the reducing gas RG is discharged from the discharge hole 212 located directly below the introduction hole 222, the discharge flow rate of the reducing gas RG from the discharge hole 212 is extremely small. The other part of the reducing gas RG spreads in the plane direction (XY plane direction) orthogonal to the vertical direction along the upper surface of the bottom wall 210, and the discharge hole located on the peripheral side of the bottom wall 210 while the flow velocity decreases. It is discharged from 212. As a result, the discharge flow rate of the reducing gas RG of the discharge hole 212 located on the peripheral side of the bottom wall 210 is larger than the discharge flow rate of the reducing gas RG of the discharge hole 212 located at the center of the bottom wall 210. The discharge flow rate of the reducing gas RG from each of the discharge holes 212 of the above varies (see FIG. 6B). As a result, the degree of reduction on the inner peripheral side of the plurality of tubular precursors 100P may vary.

On the other hand, the second gas supply body 200B has the same configuration as the gas supply body 200 (see FIGS. 4 and 5) described above. Therefore, as shown in FIGS. 7A and 7B, in the second gas supply body 200B, the reducing gas RG introduced into the space R (second space R2) of the gas supply body 200 from the introduction hole 222. Directly hits the perforated plate 300, not the bottom wall 210. Therefore, a part of the reducing gas RG passes through the communication hole 310 located directly below the introduction hole 222 and flows into the first space R1. At this time, since the diameter of each communication hole 310 is smaller than the diameter of the introduction hole 222, the flow velocity of the reducing gas RG passing through the communication hole 310 located directly below the introduction hole 222 is lowered by the flow path resistance of the communication hole 310. To do. Further, the other part of the reducing gas RG spreads in the plane direction (XY plane direction) orthogonal to the vertical direction along the upper surface of the perforated plate 300, and is located on the peripheral side of the perforated plate 300 while decreasing the flow velocity. It passes through the communication hole 310 and flows into the first space R1. As a result, the inflow amount of the reducing gas RG from the communication hole 310 located in the central portion of the perforated plate 300 to the first space R1 and the communication hole 310 located on the peripheral side of the perforated plate 300 to the first space R1. The difference from the inflow of the reducing gas RG is relatively small. After that, when the reducing gas RG that has flowed into the first space R1 from each of the plurality of communication holes 310 of the perforated plate 300 passes through the first space R1, the flow velocity difference between them is further reduced, and the bottom is It is discharged from a plurality of discharge holes 212 formed in the wall 210. As a result, as compared with the first oxygen permeable membrane structure 100A, the discharge flow rate of the reducing gas RG of the discharge hole 212 located at the center of the bottom wall 210 and the discharge hole 212 located on the peripheral side of the bottom wall 210. The difference from the discharge flow rate of the reducing gas RG is small, and it is possible to suppress the variation in the discharge flow rate of the reducing gas RG from each of the plurality of discharge holes 212. As a result, it is possible to efficiently manufacture the plurality of oxygen permeable membrane structures 100 while suppressing the variation in the degree of reduction on the inner peripheral side of the plurality of tubular precursors 100P.

In FIG. 7A, the hole area ratio of the communication hole 310 in the perforated plate 300 is 50%, and in FIG. 7B, the hole area ratio of the communication hole 310 in the perforated plate 300 is 10%. As shown in FIGS. 7A and 7B, the lower the pore area ratio of the communication holes 310 in the perforated plate 300, the more the reducing gas RG flows into the first space R1 from the plurality of communication holes 310 of the perforated plate 300. Since the effect of reducing the amount difference is improved, it can be seen that the variation in the discharge flow rate of the reducing gas RG from each of the plurality of discharge holes 212 can be suppressed more effectively.

FIG. 8 shows the degree of variation (%) in the discharge flow rate of the reducing gas RG, the hole area ratio (%) of the communication hole 310, the thickness (mm) of the perforated plate 300, and the introduction flow rate (m) from the introduction hole 222. It is explanatory drawing which shows the relationship with / s). FIG. 8A shows each of the plurality of discharge holes 212 when a plurality of gas feeders having different hole area ratios of the communication holes 310 in the perforated plate 300 are used with reference to the gas supply body 200 described above. The experimental results of measuring the variation in the discharge flow rate of the reduced gas RG from the above are shown. In FIG. 8A, it is assumed that the inflow velocity of the reducing gas RG in the introduction hole 222 is 10 m / s, and the thickness of the perforated plate 300 is 10 mm. According to FIG. 8A, when the hole area ratio of the communication hole 310 is 20% or less, the variation in the discharge flow rate of the reducing gas RG is suppressed to the reference value (1%) or less, and the hole area of the communication hole 310 is suppressed. When the rate exceeds 20%, it can be seen that the variation in the discharge flow rate of the reducing gas RG exceeds the reference value. Further, it can be seen that when the hole area ratio of the communication hole 310 exceeds 20%, the slope of the increase in the variation in the discharge flow rate of the reducing gas RG becomes large. Therefore, it can be seen that the hole area ratio of the communication hole 310 is preferably 20% or less.

FIG. 8B shows the reducing gas RGs from each of the plurality of discharge holes 212 when a plurality of gas feeders having different thicknesses of the perforated plates 300 are used with reference to the gas feeder 200 described above. The experimental results of measuring the variation in the discharge flow rate of the gas are shown. In FIG. 8B, it is assumed that the inflow velocity of the reducing gas RG in the introduction hole 222 is 10 m / s, and the hole area ratio of the communication hole 310 is the same. According to FIG. 8B, when the thickness of the perforated plate 300 is 1 mm or more, the variation in the discharge flow rate of the reducing gas RG is suppressed to the reference value (1%) or less, and the thickness of the perforated plate 300 is 1 mm. If it is less than, it can be seen that the variation in the discharge flow rate of the reducing gas RG exceeds the reference value. Therefore, it can be seen that the thickness of the perforated plate 300 is preferably 1 mm or more.

FIG. 8C shows the reduction gas RG from each of the plurality of discharge holes 212 when the introduction flow rate (m / s) from the introduction hole 222 is changed while using the gas supply body 200 described above. The experimental results of measuring the variation of the discharge flow rate are shown. In FIG. 8C, it is assumed that the hole area ratios of the communication holes 310 are the same and the thickness of the perforated plate 300 is 10 mm. According to FIG. 8C, when the introduction flow rate from the introduction hole 222 is 10 m / s or less, the variation in the discharge flow rate of the reducing gas RG is suppressed to the reference value (1%) or less, and the thickness of the perforated plate 300 is suppressed. It can be seen that when the value exceeds 10 m / s, the variation in the discharge flow rate of the reducing gas RG exceeds the reference value. Therefore, it can be seen that the introduction flow rate from the introduction hole 222 is preferably 10 m / s or less.

B. Modification example:
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be transformed into various forms without departing from the gist thereof. For example, the following modifications are also possible.

The configuration of the oxygen permeable membrane structure 100 in the above embodiment is merely an example and can be variously deformed. For example, in the above embodiment, the oxygen permeable membrane structure 100 is composed of a support 114, a modified catalyst layer 112, an oxygen permeable membrane 111, and an oxygen dissociation catalyst layer 113. The structure 100 may not include the support 114 or may not include the oxygen dissociation catalyst layer 113. For example, the oxygen permeable film structure 100 does not have an independent support, but the oxygen permeable film 111 (oxygen permeable layer) has a support function, and the modified catalyst layer 112 has a support function. (Including the form in which the material for forming the modified catalyst layer is not contained in the axial end of the support and the material for forming the modified catalyst layer is contained in the portion other than the end). The oxygen dissociation catalyst layer 113 may have the function of a support. Further, the oxygen permeable membrane structure 100 is exemplified as the tubular work, but the present invention is not limited to this, and the tubular work has a tubular body having through holes, and the inner peripheral side of the tubular precursor is reduced. Anything that is formed by doing so may be used. The outer peripheral side of the tubular work is preferably formed of a material (for example, an oxide) that should not be reduced.

Further, in the above embodiment, the oxygen permeable membrane structure 100 is a member having a substantially cylindrical shape, but the shape of the oxygen permeable membrane structure 100 can be variously deformed, and may be, for example, a square cylinder. ..

Further, the bottom wall 210, the ceiling wall 220 and the perforated plate 300 of the gas supply body 200 are not limited to the flat plate shape, and may be curved, for example. Further, the shape of the bottom wall 210, the ceiling wall 220, and the perforated plate 300 in the vertical direction is not limited to a rectangular shape, and may be, for example, a circular shape. Further, the plurality of discharge holes 212 and the plurality of communication holes 310 may not be arranged at equal intervals. Further, the introduction hole 222 may be formed at a position deviated from the center of the ceiling wall 220. Further, the gas supply body 200 may have a configuration (see FIG. 6) that does not include the perforated plate 300.

Further, as the facing body, the perforated plate 300 that partitions the space R of the gas supply body 200 is illustrated, but the facing body faces the introduction hole 222 in the space R of the gas supply body 200 and is viewed in the vertical direction. It may be configured to be arranged in a part of the space R. Further, the opposing body is not limited to a punching board such as the perforated plate 300, and may be, for example, a porous body in which a plurality of pores are formed, or a dense body in which no pores or communication holes are formed. Good. Further, in the above embodiment, the perforated plate 300 may be arranged so as to be inclined with respect to the bottom wall 210 and the ceiling wall 220. Further, the perforated plate 300 may be arranged at a position deviated from the substantially center of the space R in the vertical direction.

In the above embodiment, as the first space, the space facing the entire upper surface of the bottom wall 210 is illustrated as the first space R1, but the first space is at least the discharge hole 212 of the upper surface of the bottom wall 210. Any space may be used as long as it faces the portion (first portion) that surrounds all of the above. Further, in the above embodiment, as the second space, the space facing the entire lower surface of the ceiling wall 220 is illustrated as the second space R2, but the second space is at least introduced from the lower surface of the ceiling wall 220. Any space may be used as long as it faces the portion (second portion) in which the hole 222 is formed.

Further, the hole area ratio of the communication hole 310 in the perforated plate 300 may be higher than 20%. Further, the thickness of the perforated plate 300 may be 1 mm or less. The arrangement interval between the communication holes 310 in the perforated plate 300 is preferably larger than the diameter of one communication hole 310. For example, the arrangement interval between the communication holes 310 is 10 mm, and the diameter of the communication holes 310 is 1 mm or more and 6 mm or less.

Further, the material constituting each member in the above embodiment is merely an example, and each member may be composed of another material. For example, the oxygen dissociation catalyst layer 113 is a LaCrO ₃ type oxide, may be formed by perovskite oxide containing at least one of Ni and noble metals, it is formed of a material containing Ni and noble metals It may be.

100: Oxygen permeable membrane structure 100A: First oxygen permeable membrane structure 100P: Cylindrical precursor 110: Through hole 111: Oxygen permeable membrane 112: Modified catalyst layer 112P: Modified catalyst layer precursor 113: Oxygen dissociation Catalyst layer 114: Support 200: Gas feeder 200A: First gas feeder 200B: Second gas feeder 201: First lid 202: Second lid 210: Bottom wall 212: Discharge hole 214 : Connecting part 220: Ceiling wall 222: Introduction hole 230: Side wall 232: First side wall 234: Second side wall 236: Outer peripheral surface 300: Perforated plate 310: Communication hole FG: Fuel gas R1: First space R2: Second space R: Space RG: Reducing gas S1: Air chamber S2: Fuel chamber S3: Top surface S4: Bottom surface

Claims (6)

In a method for manufacturing a tubular work having a tubular body having a through hole formed therein,
The first preparatory step of preparing a plurality of tubular precursors, which are the precursors of the tubular body, and
A box-shaped gas supply body in which a space is formed inside, the first wall in which a plurality of discharge holes communicating with the space are formed, and the first wall in a first direction through the space. It has a second wall that is arranged to face the wall and has one introduction hole that communicates with the space, and a side wall that connects the peripheral edge of the first wall and the peripheral edge of the second wall. The second preparatory step to prepare the gas feeder and
A connecting step of individually connecting each of the plurality of discharge holes formed in the first wall of the gas supply body and the inner peripheral side of each of the plurality of tubular precursors.
After the connecting step, the reducing gas is introduced into the introduction hole formed in the second wall of the gas supply body to reduce the inner peripheral side of the plurality of tubular precursors, and the plurality of tubular precursors are reduced. And the reduction process to form the tubular body of
To prepare
A method for manufacturing a tubular work, which is characterized in that. In the method for manufacturing a tubular work according to claim 1,
In the first directional view, at least a part of the plurality of discharge holes is located outside the outer shape of the introduction hole.
The gas supply body further includes an opposing body that is arranged in the space of the gas supply body and partially faces the introduction hole.
A method for manufacturing a tubular work, which is characterized in that. In the method for manufacturing a tubular work according to claim 2,
The opposing body
The space of the gas supply body is the first space of the first wall facing the first portion of the first wall in which at least all of the plurality of discharge holes are formed, and the second wall of the second wall. It is arranged so as to partition at least a second space facing the second portion where the introduction hole is formed.
Moreover, it is a porous body in which a plurality of communication holes communicating from the surface on the first space side to the surface on the second space side are formed.
A method for manufacturing a tubular work, which is characterized in that. In the method for manufacturing a tubular work according to claim 3,
In at least one cross section orthogonal to the thickness direction of the facing body, the hole area ratio, which is the total ratio of the areas of the plurality of communicating holes to the outer area of the facing body, is 20% or less.
A method for manufacturing a tubular work, which is characterized in that. In the method for manufacturing a tubular work according to claim 4,
The hole area ratio of the plurality of communication holes is 5% or more.
A method for manufacturing a tubular work, which is characterized in that. In the method for manufacturing a tubular work according to any one of claims 3 to 5.
The thickness of the opposing body is 1 mm or more.
A method for manufacturing a tubular work, which is characterized in that.

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