JP4898725B2 - Hydrogen separator - Google Patents

Description

  The present invention relates to a hydrogen separator capable of selecting and separating hydrogen from a source gas, and more particularly to a hydrogen separator having a structure capable of preventing damage to a hydrogen separator cylinder.

As one of the industrial methods for producing hydrogen, a steam reforming method of hydrocarbon gas is known. In this steam reforming method, a reformer filled with a reforming catalyst such as a granule is usually used.
However, the reformed gas obtained from the reformer contains by-products such as CO and CO ₂ and surplus H ₂ O in addition to hydrogen as the main component. If it is used as it is for a battery, battery performance will be impaired.

  That is, of the fuel cells, CO in hydrogen gas used in phosphoric acid fuel cells is limited to about 1% (vol%), and in solid polymer fuel cells, the limit is about 100 ppm (vol ppm). Since the performance deteriorates significantly, these by-products need to be removed before being introduced into the fuel cell.

As a countermeasure, a membrane reactor has been developed in which the generation of the reformed gas by the reformer and the purification of the reformed gas can be performed with one apparatus (see Patent Document 1).
However, this type of membrane reactor has a multi-tube configuration in which a hydrogen separation tube having a hydrogen permeable membrane on its surface is arranged in a reaction tube (outer tube) that is a storage container. The membrane reactor is reformed by filling the gap between the outer pipe and the hydrogen separation pipe with a granular reforming catalyst and supplying the raw material gas into the gap. At this time, since the filled catalyst repeatedly contacts the hydrogen separation tube, there was a problem that, for example, the hydrogen permeable membrane was damaged.

  In order to solve this problem, in recent years, a hydrogen separation cylinder shaped like a test tube using a reforming catalyst / support is used as a support for the hydrogen permeable membrane, and the hydrogen separation cylinder is fixedly attached. A hydrogen separator equipped with metal fittings has been proposed (see Patent Document 2).

As an example of this type of hydrogen separation apparatus, as illustrated in FIG. 6, for example, one end of a hydrogen separation cylinder P1 is fixed to a mounting bracket P2, and the hydrogen separation cylinder P1 is inserted into the hydrogen separation cylinder P1 via an internal channel P3 in the mounting bracket P2. A structure in which source gas is supplied is conceivable. In this hydrogen separator, hydrogen is separated from the raw material gas by the action of the reforming catalyst and the hydrogen permeable membrane of the hydrogen separator cylinder P1, and hydrogen is separated and discharged from the outer peripheral surface of the hydrogen separator cylinder P1 to the outside.
JP 2005-58823 A JP 2004-149332 A

  In the hydrogen separation apparatus, in order to prevent the raw material gas from leaking to the outer peripheral side of the hydrogen separation cylinder P1 (that is, the side to which hydrogen gas is supplied), for example, expanded graphite is provided between the hydrogen separation cylinder P1 and the mounting bracket P2. A seal member P4 made of metal is disposed, and this seal member P4 is pressed and fixed by a pressing metal fitting P5 and a fixing metal fitting P6. Since the main component of the hydrogen separation cylinder P1 itself is ceramics, the surface and the like are fixed during the fixing. It was sometimes damaged.

  That is, the pressing fitting P5 is pressed along the axial direction of the hydrogen separation cylinder P1 by tightening the fixing fitting P6, and further, the sealing member P4 is pressed along the coaxial direction by the pressing fitting P5. Depending on the degree of force applied, the axial direction of the pressing metal fitting P5 and the axial direction of the hydrogen separation cylinder P1 may be shifted, and the hydrogen separation cylinder P1 may be inclined. As a result, the hydrogen separation cylinder P1 may be damaged because the opening end of the pressing fitting P5 hits the outer peripheral surface of the hydrogen separation cylinder P1.

  The present invention has been made in order to solve the above-described problems, and the object thereof is to prevent the hydrogen separation cylinder from being damaged by the press fitting or the like when the seal member is pressed by the press fitting or the like. It is to provide a hydrogen separator.

  (1) The invention of claim 1 is a hydrogen separation cylinder that selects and separates hydrogen from a raw material gas, an attachment member to which an axial end of the hydrogen separation cylinder is attached, and an outer fit to the hydrogen separation cylinder. A cylindrical sealing member made of expanded graphite that is hermetically sealed between the hydrogen separation cylinder and the mounting member; and the fitting member that is externally fitted to the hydrogen separation cylinder and that moves the sealing member along the axial direction. A hydrogen separation device comprising: a cylindrical pressing member that presses toward the side; and a cylindrical fixing member that is externally fitted to the hydrogen separation tube and presses the pressing member toward the mounting member along the axial direction. It is an apparatus, Comprising: The through-hole in which the said hydrogen separation cylinder of the said press member is penetrated is set large in an internal diameter toward the said fixing member side, It is characterized by the above-mentioned.

In the present invention, since the inner diameter of the through hole of the cylindrical pressing member is set larger toward the fixed member side, even when the pressing member is inclined by the pressing of the fixing member, the corner portion of the opening end of the pressing member Is less likely to hit the outer peripheral surface of the hydrogen separation cylinder, and therefore the hydrogen separation cylinder is hardly damaged.
In addition, as a hydrogen separation apparatus of this invention, what is equipped with the reforming catalyst in the hydrogen separation cylinder etc. is mentioned, for example. In addition, those that do not have a reforming catalyst, that is, those that separate hydrogen from gases (H ₂ , CO, CO ₂ , hydrocarbons (methane, etc.), water vapor) reformed by another apparatus or the like can be mentioned. . Even when a reforming catalyst is provided, hydrogen may be separated from the reformed gas.
(2) The invention of claim 2 is characterized in that a taper portion whose inner diameter increases toward the fixed member side is provided on the inner peripheral surface of the through hole of the pressing member.

  The present invention exemplifies a preferable shape of the inner peripheral surface of the through hole. In this invention, since the internal peripheral surface of a through-hole is made into the taper shape, there exists an advantage that a hydrogen-separation cylinder is hard to damage further.

(3) In invention of Claim 3, the taper angle of the said taper part is the range of 1 degree-30 degrees, It is characterized by the above-mentioned.
The present invention exemplifies a preferable taper angle. If the taper angle is within this range, the hydrogen separation cylinder is more difficult to break.

(4) The invention according to claim 4 is characterized in that a difference between the inner diameter on the fixing member side and the inner diameter on the mounting member side in the tapered portion is 1 mm or more.
The present invention illustrates a preferred inner diameter difference. If the inner diameter difference is within this range, the hydrogen separation cylinder is more difficult to break.

  (5) In the invention of claim 5, the inner peripheral surface of the through hole of the pressing member is provided with a tapered portion on the fixing member side and a straight portion parallel to the axial direction on the mounting member side. It is characterized by.

  The present invention exemplifies a preferable shape of the inner peripheral surface of the through hole. That is, in the present invention, the inner peripheral surface of the through hole of the pressing member is provided with the taper portion on the fixing member side and the straight portion on the attachment member side, so that the hydrogen separation cylinder is prevented from being damaged and the sealing member is suitable. Both pressing can be realized.

(6) The invention of claim 6 is characterized in that a smoothly curved R portion is provided between the tapered portion and the straight portion.
The inner peripheral surface of the through-hole is bent between the taper portion and the straight portion. By providing the R portion between the taper portion and the straight portion, the hydrogen separation cylinder is damaged by the bent portion. Can be suppressed.

(7) The invention of claim 7 is characterized in that the radius of the R portion is 0.1 mm or more.
In the present invention, since the radius of the R portion is as large as 0.1 mm or more and the surface is smoothly curved, there is an advantage that even when the pressing member is largely inclined, the hydrogen separation cylinder is hardly damaged.

(8) The invention according to claim 8 is characterized in that the length of the straight portion in the axial direction is 1 mm or more.
In the present invention, since the length of the straight portion in the axial direction is as large as 1 mm or more, suitable pressing of the seal member can be realized.

<Hereinafter, each configuration of the hydrogen separator of the present invention will be described>
-Examples of the source gas include a mixed gas of hydrocarbon gas such as city gas and water vapor. Alternatively, a mixed gas containing hydrogen obtained by some method (steam reforming, partial oxidation, water electrolysis, hydrogen production from biomass, etc.) can be mentioned.

  -As the hydrogen separation cylinder, a cylindrical body in which a hydrogen permeable membrane is formed on the surface of a porous support pipe (which is a reforming catalyst and support), or a surface of the porous support pipe (to prevent metal diffusion) And a cylindrical body in which a barrier layer is formed and a hydrogen permeable film is further formed on the surface of the barrier layer.

  Among these, as a material constituting the porous support tube, for example, a sintered body of a mixture of nickel and yttria stabilized zirconia, a sintered body mainly composed of a mixture of nickel and yttria stabilized zirconia (Ni-YSZ cermet, etc.) Other examples include porous ceramics and porous cermets having both the function as a support and the function as a reforming catalyst.

Examples of the hydrogen permeable film include metal films such as a Pd film and a Pd alloy film. Or an inorganic molecular sieve membrane etc. are mentioned.
As a constituent material of the barrier layer, for example, zirconia, stabilized zirconia, partially stabilized zirconia, alumina, magnesia, or a mixture or compound of these materials can be used.

-As said attachment member, metal attachment brackets, such as stainless steel of SUS316 etc. which have heat resistance and oxidation resistance, etc. are mentioned.
-Examples of the sealing member include a member in which a sheet made of expanded graphite is wound in a cylindrical shape, a sheet in which sheets made of expanded graphite are laminated, and a composite member in which they are combined.

  This expanded graphite sealing member has a dense structure excellent in sealing performance in addition to the high heat resistance inherent in graphite, and has flexibility, high compressibility, and elastic restoring force. For example, it is desirable that the seal member itself has a heat resistance and chemical resistance that does not significantly break down or change chemically even when exposed to a high temperature of 600 ° C. or higher for a long time.

The expanded graphite preferably has the following physical property values.
Density (bulk density) is 0.6 to 1.9 g / cm ³ , compression rate (based on JIS-R3453) is 10 to 90%, restoration rate (based on JIS-R3453) is 3 to 70%, oxidation start temperature (Temperature when weight decreased by 1% by heating in air) 400 ° C. or higher.

As the pressing member, for example, a metal pressing fitting (pressing ring) such as stainless steel of SUS316 having heat resistance and oxidation resistance may be used.
-As said fixing member, metal metal fittings, such as stainless steel of SUS316 etc. which have heat resistance and oxidation resistance, etc. are mentioned.

Hereinafter, the best embodiment of the present invention will be described.
[First Embodiment]
Here, a hydrogen separator that supplies fuel gas (hydrogen gas) to the fuel cell will be described.

a) First, the overall configuration of the hydrogen separator according to this embodiment will be described.
As shown in FIG. 1, a hydrogen separation device (hydrogen separation module) 1 according to the present embodiment includes a test tubular hydrogen separation cylinder 3 closed at one end, and a cylindrical shape into which an open end side of the hydrogen separation cylinder 3 is inserted. The mounting bracket 5, the pressing bracket 9 that presses the cylindrical seal member 7 disposed between the outer peripheral surface of the hydrogen separation cylinder 3 and the inner peripheral surface of the mounting bracket 5, and the outer surface of the pressing bracket 9 for mounting. A cylindrical fixing metal fitting 11 screwed to the metal fitting 5 is provided.

  The hydrogen separation cylinder 3 selectively separates hydrogen from a raw material gas (for example, a mixed gas of hydrocarbon gas such as methane and water vapor) introduced into the central hole 13 at the axial center thereof, and the hydrogen separation cylinder 3 It is a member supplied to the outer peripheral side. The hydrogen separation cylinder 3 includes a test tube (a reforming catalyst / support) porous support tube 15 that is closed at one end, a barrier layer 19 that covers the outer surface of the porous support tube 15, and a barrier layer 19. And a hydrogen permeable membrane 21 covering the outer surface of the substrate.

  Among these, the porous support tube 15 is an air-permeable test tubular support having a role as a reforming catalyst and a role of supporting the hydrogen permeable membrane 21 and the like. The reformed gas is generated by steam reforming the gas.

The hydrogen permeable membrane 21 is a thin film that selectively permeates and purifies hydrogen from the reformed gas modified in the porous support tube 15.
In the barrier layer 19, the metal component (for example, Ni) of the porous support tube 15 and the component (for example, Pd) of the hydrogen permeable membrane 21 enter (diffuse) each other, so that the hydrogen permeable performance of the hydrogen permeable membrane 21 deteriorates. This is a porous layer (interdiffusion prevention layer) for preventing this.

  The mounting bracket 5 is a cylindrical bracket that forms the base of the hydrogen separation apparatus 1, and from the distal end side, a distal end side cylindrical portion 25 having a threaded portion 23 on the outer periphery and an annularly projecting outer periphery side. A flange portion 27 and a proximal-side cylindrical portion 29 (to which a pipe or the like for supplying a raw material gas is connected) are provided.

  A through-hole (hollow part) 31 serving as a raw material gas flow path is formed at the axial center of the mounting bracket 5, and the hollow part 31 has an end part on the base end side (right side of the figure) of the hydrogen separation cylinder 3. Is housed. Specifically, the inner diameter of the hollow portion 31 is set to be smaller on the inner side of the flange portion 27 than on the inner side of the distal end side cylindrical portion 25, and at the corner on the distal end side on the inner side of the flange portion 27, A recess 33 that is cut out in a step shape is formed, and the end of the hydrogen separation cylinder 3 is fitted in the recess 33.

  The sealing member 7 is a cylindrical airtight member made of expanded graphite, and in the space 41 between the inner peripheral surface of the front end side cylindrical portion 25 of the mounting bracket 5 and the outer peripheral surface of the hydrogen separation cylinder 3, It is arranged adjacent to the pressing fitting 9. Since the seal member 7 is held in the space 41 in a state compressed by the pressing of the pressing fitting 9, and thus in a state where the periphery is pressed, the leakage of the source gas in the space 41 is prevented. Yes. The seal member 7 includes a first seal member 43 disposed on the front end side and a second seal member 45 disposed on the rear end side.

  The fixing bracket 11 extends in the radial direction (perpendicular to the axial direction) and presses the pressing bracket 9 toward the proximal end side, and the proximal end side along the axial direction from the outer peripheral end of the pressing plate 35. And a cylindrical portion 39 having a threaded portion 37 on the inner peripheral surface. Therefore, the sealing member 7 can be pressed to the proximal end side via the pressing fitting 9 by screwing and tightening the screw portion 37 of the fixing fitting 11 and the screwing portion 23 of the mounting fitting 5.

  The pressing fitting 9 is a cylindrical tubular fitting, and in a tubular space 41 formed between the inner peripheral surface of the distal end side tubular portion 25 of the mounting bracket 5 and the outer peripheral surface of the hydrogen separation cylinder 3. Therefore, it is arranged adjacent to the seal member 7. The front end side of the pressing metal 9 is in contact with the pressing plate 35 of the fixing metal 11, and the rear end side is in contact with the seal member 7.

  Specifically, as shown in an enlarged view in FIG. 2, of the inner peripheral surface of the through hole 51 formed at the axial center of the pressing fitting 9, the right side (seal member 7 side) is parallel to the axial direction. A straight portion 53 having a surface is formed. Further, a tapered portion 55 having a tapered shape whose inner diameter increases toward the left side is formed on the left side of the drawing (on the side of the fixing bracket 11). Furthermore, between the straight part 53 and the taper part 55, the curved R part 57 which connects both smoothly is formed. In addition, C chamfered portions 59 and 61 with C chamfering are formed at corners of both opening ends of the through hole 51.

Next, the preferable dimension of each part of the press metal fitting 9 is demonstrated based on FIG. In FIG. 3, the respective parts are shown deformed for explanation.

M> N (1)
N> 1mm (2)
φD2> φD1 + 1mm (3)
Radius of radius R (radius r) ≧ 0.1 mm (4)
Chamfering dimension of C chamfered part (C chamfering) ≤ 0.2mm (5)
1 ° ≦ θ ≦ 30 (6)

L: Axial length of the press fitting M: Axial length of the tapered portion N: Axial length of the straight portion φD1: Inner diameter of the straight portion of the through hole φD2: Opening end of the through hole tapered portion on the fixing bracket side Inside diameter φD3: Outer diameter of the press fitting θ: Taper angle

As shown in FIG. 1, an internal intubation 50 is disposed inside the hydrogen separation apparatus 1 (specifically, the center hole 13 of the hydrogen separation cylinder 3). This inner tube 50 is a member that supplies the raw material gas from the base end side of the hydrogen separation device 1 to the front end side of the hydrogen separation cylinder 3, and is an off-gas after reaction (CO, CO ₂ , H ₂ , methane, water vapor). Is discharged from the proximal end side of the hydrogen separator 1 along the outer periphery of the inner intubation 50.

b) Next, the overall configuration of the hydrogen separation system to which the hydrogen separator 1 is attached will be described.
As shown in FIG. 4, a plurality of (for example, three) hydrogen separation apparatuses 1 described above are accommodated and fixed in a stainless steel cylindrical storage container (reaction tube) 71 such as SUS316.

  The reaction tube 71 includes a cylindrical outer peripheral wall 73, a substrate 75 that closes one of the outer peripheral walls 73 in the axial direction, and a lid plate 77 that closes the other. It is arranged to penetrate. Specifically, each hydrogen separator 1 is fixed to the substrate 75 by welding or the like at the flange portion 27 of each mounting bracket 5 (see FIG. 1).

  Further, a pipe 79 for supplying a source gas is attached to the lower part of the mounting bracket 5 by, for example, a nut 81. Further, a hydrogen extraction hole 83 for taking out hydrogen is provided in the outer peripheral wall 73 of the reaction tube 71.

  Therefore, in this hydrogen separation system, when the source gas is supplied into the hydrogen separation cylinder 3 from the pipe 79 attached to the lower side of the mounting bracket 5 of the hydrogen separation apparatus 1, hydrogen is separated by the hydrogen separation cylinder 3. Then, hydrogen flows into the reaction tube 71 from the outer peripheral side. Then, the hydrogen filled in the reaction tube 71 is taken out through the hydrogen take-out hole 83.

The hydrogen taken out from the hydrogen take-out hole 83 is supplied to a fuel cell (not shown) to generate power.
c) Next, the manufacturing method of the hydrogen separator 1 of this embodiment is demonstrated.
<Method for Producing Hydrogen Separation Tube 3>
For example, 60 parts by mass of nickel oxide and 40 parts by mass (8YSZ) of zirconia in which 8 mol% of yttria is dissolved are mixed. Further, graphite powder (or starch) is mixed as a pore forming agent to prepare a mixed material.

And a bottomed cylindrical tube is shape | molded by extrusion molding using this mixed material.
Next, after the bottomed cylindrical tube is dried, it is degreased and fired at 1400 ° C. for 1 hour to produce a porous support tube 15 formed of NiO—YSZ.

Separately from this, 8YSZ, a binder and ethanol are added to prepare a slurry.
Next, this slurry is applied onto the surface of the porous support tube 15 by a dip coating method (or spray spraying method, printing method, etc.) to form a coating layer.

Next, this coat layer is baked by heat treatment at 1300 ° C. to form the barrier layer 19.
The porous support tube 15 covered with the barrier layer 19 is ultrasonically cleaned with ethanol for 30 minutes and dried at 120 ° C.

Next, a hydrogen permeable film 21 made of Pd or the like is formed by an electroless plating method (or a vacuum deposition method, a sputtering method, or the like) so as to cover the barrier layer 19.
Next, reduction treatment is performed at 600 ° C. for 3 hours under a hydrogen atmosphere, thereby completing the hydrogen separation cylinder 3.
<Method for Manufacturing Seal Member 7>
When the first seal member 43 is manufactured, for example, an expanded graphite sheet is cut into an annular shape, and the annular sheet is laminated so that the respective through holes are aligned.

Next, this laminated body is oxidized with an oxidizing agent such as concentrated sulfuric acid and nitric acid to expand the expanded graphite, for example, about 100 to 300 times.
Thereafter, the expanded graphite is loaded and compressed by press molding so that the density range is, for example, 0.6 to 1.9 g / cm ³ .

When the second seal member 45 is manufactured, a tubular laminate is formed by winding a similar expanded graphite sheet (a mandrel or the like (not shown)) (the mandrel or the like is removed later).
Next, the expanded graphite is similarly expanded by oxidizing the laminate with an oxidizing agent such as concentrated sulfuric acid or nitric acid.

Thereafter, the expanded graphite is loaded and compressed so as to be in the above density range.
<Assembly method of hydrogen separator 1>
The second sealing material 45, the first sealing material 43, and the pressing metal 9 are fitted in the hollow portion 31 of the mounting metal 5 in this order.

Next, the open end side of the hydrogen separation cylinder 3 is inserted so as to pass through the through hole of the pressing fitting 9, the first sealing material 43, and the second sealing material 45, and the end of the hydrogen separation cylinder 3 is attached to the mounting fitting. 5 is fitted in the recess 33.
Next, the fixing bracket 11 is fitted from the distal end side of the hydrogen separation cylinder 3, the screw portion 37 of the fixing bracket 11 and the screw portion 23 of the mounting bracket 5 are screwed together, and the pressing bracket 9 is connected to the proximal end side by the fixing bracket 11. The hydrogen separation apparatus 1 is completed by pressing the seal member 7 by tightening to the above.

  d) As described above, in this embodiment, as the metal fitting for pressing the seal member 7, the pressure metal fitting 9 having the through hole 51 having a taper-shaped opening on the side of the metal fitting 11 is used. In this case, even if the hydrogen separation cylinder 3 is tilted, there is an effect that the outer peripheral surface of the hydrogen separation cylinder 3 is hardly damaged by the corners of the opening end of the pressing member 9.

  Further, an R portion 57 is formed between the taper portion 55 and the straight portion 53 of the pressing member 9, and C chamfered portions 59 and 61 are formed at the corners of the opening end of the pressing member 9. Also from this point, there is an advantage that the hydrogen separation cylinder 3 is hardly damaged. C chamfering also exists on the outer peripheral side of the end portion.

The hydrogen separation apparatus 1 of the present embodiment is a cantilever type in which only one end side (open end) of the hydrogen separation cylinder 3 is fixed. However, in order to increase the stability against vibrations of the hydrogen separation cylinder 3, The closed end side of the separation cylinder 3 may be fixed to the reaction tube 71 or the like.
[Second Embodiment]
Next, although the hydrogen separation apparatus of 2nd Embodiment is demonstrated, description of the content similar to the said 1st Embodiment is abbreviate | omitted.

  As shown in FIG. 5, in the hydrogen separation device 91 of the present embodiment, a cylindrical hydrogen separation cylinder 93 having both ends opened is used. As in the embodiment, a fixing structure including mounting brackets 95 and 97, seal members 99 and 101, pressing brackets 103 and 105, and fixing brackets 107 and 109 is formed.

  In other words, in the axial direction of the hydrogen separation cylinder 93, one fixing structure including the mounting bracket 95, the seal member 99, the pressing bracket 103, and the fixing bracket 107, the mounting bracket 97, the seal member 101, The other fixing structure including the pressing metal 105 and the fixing metal 109 is provided.

  In the present embodiment, for example, the raw material gas is supplied from the right side of the figure, and the raw material gas after the reaction is discharged from the left side of the figure. Further, the hydrogen separated in the hydrogen separation cylinder 93 is supplied into the reaction tube 119 from the outer peripheral side of the hydrogen separation cylinder 93.

Also in this embodiment, there exists an effect similar to the said 1st Embodiment. Further, since both ends of the hydrogen separation cylinder 93 are fixed, there is an advantage that the stability is high.
As a modification, a cylindrical hydrogen separation cylinder having both ends opened is used, but a configuration in which one of the hydrogen separation devices in the axial direction is closed by the fixing structure can also be adopted.

<Experimental example 1>
Next, an experiment in which the above-described hydrogen separation apparatus was actually manufactured and its performance was confirmed will be described.

<Sample preparation method>
As a sample (Example 1) used for the experiment, 20 hydrogen separators having a pressing member having a tapered portion, similar to the first embodiment, were produced.

In addition, the dimension of each part, such as a press member, is as follows.
L: 8 mm
M: 6 mm
N: 2 mm
φD1: 10 mm
φD2: 11.5mm
φD3: 13mm
θ: 14 °
R radius of R part: 2mm
C chamfering: 0.2mm
Diameter of hydrogen separator: 9.9mm
Further, as Comparative Example 10, ten conventional hydrogen separators having a pressing member without a tapered portion were produced. Other than the pressing member, the second embodiment is the same as the first embodiment.

<Experiment method>
Then, the fixing member was fastened to each sample described above at a fastening pressure of 35 N / mm ² , and then the hydrogen separator was disassembled to examine the degree of damage to the hydrogen separator.

<Experimental result>
As a result, in the examples within the scope of the present invention, damage to the hydrogen separation cylinder was as small as 5%, which was preferable. On the other hand, in the comparative example, the damage of the hydrogen separation cylinder is 40%, which is not preferable.

<Experimental example 2>
Samples (Examples 2 to 6) substantially the same as those of Experimental Example 1 were prepared, and the degree of damage to the hydrogen separation cylinder was examined.

  Specifically, as shown in Table 1 below, ten samples of each example with different θ ranges were prepared, and the rate at which the hydrogen separation cylinder was damaged was examined. However, other dimensions and other conditions are the same as in Experimental Example 1.

尚、本発明は前記実施形態になんら限定されるものではなく、本発明を逸脱しない範囲において種々の態様で実施しうることはいうまでもない。

In addition, this invention is not limited to the said embodiment at all, and it cannot be overemphasized that it can implement with a various aspect in the range which does not deviate from this invention.

It is sectional drawing which fractures | ruptures and shows the hydrogen separator of 1st Embodiment along an axial direction. It is sectional drawing which fractures | ruptures and expands the press metal fitting in 1st Embodiment along an axial direction. It is explanatory drawing explaining the dimension etc. of a press metal fitting. 1 shows a hydrogen separation system in which the hydrogen separation apparatus of the first embodiment is used, (a) is a cross-sectional view taken along line AA ′ of (b), and (b) is a hydrogen separation system showing a reaction tube broken in the axial direction. FIG. It is sectional drawing which fractures | ruptures and shows the hydrogen separator of 2nd Embodiment along an axial direction. It is explanatory drawing of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,91 ... Hydrogen separator 3,93 ... Hydrogen separation cylinder 5,95 ... Mounting bracket 7,99,101 ... Seal member 9,103,105 ... Pressing bracket 11,107,109 ... Fixing bracket 53 ... Straight part 55 ... Tapered portion 57 ... R portion 59, 61 ... C chamfered portion 71 ... Reaction tube (storage container)

Claims (8)

A hydrogen separation cylinder for selecting and separating hydrogen from the source gas;
An attachment member to which an axial end of the hydrogen separation cylinder is attached;
A tubular sealing member made of expanded graphite that is fitted over the hydrogen separation cylinder and hermetically seals between the hydrogen separation cylinder and the mounting member;
A cylindrical pressing member that is externally fitted to the hydrogen separation cylinder and presses the seal member toward the mounting member along the axial direction;
A cylindrical fixing member that is fitted over the hydrogen separation cylinder and presses the pressing member toward the mounting member along the axial direction;
A hydrogen separator comprising:
The through-hole through which the hydrogen separation cylinder of the pressing member is inserted has a larger inner diameter toward the fixed member.   2. The hydrogen separator according to claim 1, wherein a taper portion having an inner diameter that increases toward the fixed member is provided on an inner peripheral surface of the through hole of the pressing member.   3. The hydrogen separator according to claim 2, wherein a taper angle of the taper portion is in a range of 1 ° to 30 °.   3. The hydrogen separator according to claim 2, wherein a difference between an inner diameter on the fixing member side and an inner diameter on the mounting member side in the tapered portion is 1 mm or more.   The inner peripheral surface of the through hole of the pressing member includes a taper portion on the fixed member side and a straight portion parallel to the axial direction on the attachment member side. The hydrogen separator according to any one of the above.   6. The hydrogen separator according to claim 5, wherein a smoothly curved R portion is provided between the tapered portion and the straight portion.   The hydrogen separation apparatus according to claim 6, wherein the radius of the R portion is 0.1 mm or more. 8. The hydrogen separator according to claim 5, wherein a length of the straight portion in the axial direction is 1 mm or more.

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