JP6421139B2 - Monolith type separation membrane structure - Google Patents

Description

  The present invention relates to a monolithic separation membrane structure.

  Conventionally, a filtration film-forming method has been widely used as a method for forming a porous film on the inner surfaces of a plurality of through holes formed in a monolithic substrate (see, for example, Patent Document 1). The filtration film-forming method is a technique for depositing a porous material on the inner surface of a through-hole by lowering the outer peripheral surface side of the monolith substrate while circulating the slurry containing the porous material through the through-hole. .

International Publication No. 2008/010452

  However, in the filtration film forming method, a non-uniform negative pressure is likely to be generated on the inner surface of the through hole, so that the thickness of the porous film in a region where the negative pressure is small may be reduced. When such a porous membrane is used for the separation of a mixed fluid (liquid mixture or gas mixture), the load is concentrated on a thin portion of the porous membrane, so that the durability of the monolith type separation membrane structure is lowered. is there.

  This invention is made | formed in view of the above-mentioned situation, and aims at providing the monolith type separation membrane structure which can improve durability.

  The monolith type separation membrane structure according to the present invention includes a monolith type substrate and a porous membrane. The monolith substrate has a plurality of through holes including a first through hole adjacent to an outflow surface through which a permeation component flows out. The porous membrane has a plurality of porous membranes including the first porous membrane formed inside the first through hole. The ratio of the second average thickness of the first porous membrane opposite to the outflow surface to the first average thickness of the outflow surface of the first porous membrane is 0.6 or more.

  ADVANTAGE OF THE INVENTION According to this invention, the monolith type separation membrane structure which can improve durability can be provided.

The perspective view of the monolith type separation membrane structure concerning a 1st embodiment AA sectional view of FIG. Partial enlarged view of FIG. BB sectional view of FIG. The perspective view of the monolith type separation membrane structure concerning a 2nd embodiment FF sectional view of FIG. Partial enlarged view of FIG.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  In the following description, “monolith” means a shape having a plurality of through-holes formed in the longitudinal direction, and is a concept including a honeycomb.

1. First Embodiment (Configuration of Monolith Separation Membrane Structure 100)
FIG. 1 is a perspective view of a monolithic separation membrane structure 100 according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. In FIG. 1, the internal structure of the monolith type separation membrane structure 100 is partially shown. The arrows in FIG. 1 indicate the flow of permeation components (for example, water vapor).

  The monolith type separation membrane structure 100 includes a monolith type substrate 10, a plurality of porous membranes 20, a first seal part 26, and a second seal part 27.

  The monolith type substrate 10 includes a main body portion 11, a plurality of first pluggings 12, and a plurality of second pluggings 13.

  The main body 11 is formed in a cylindrical shape. The length of the main body 11 in the longitudinal direction can be 150 to 2000 mm. The diameter of the main body 11 can be 30 to 220 mm. The main body 11 may be formed in an elliptical column shape or a polygonal column shape.

The main body 11 is made of a porous material. As the porous material of the main body 11, a ceramic material, a metal material, a resin material, or the like can be used. As the aggregate of the ceramic material, alumina (Al ₂ O ₃ ), titania (TiO ₂ ), mullite (Al ₂ O ₃ .SiO ₂ ), cerven and cordierite (Mg ₂ Al ₄ Si ₅ O ₁₈ ) are used. In view of availability, stability of clay, and corrosion resistance, alumina is preferable. The main body 11 may include an inorganic binder in addition to the porous material. As the inorganic binder, at least one of titania, mullite, easily sinterable alumina, silica, glass frit, clay mineral, and easily sinterable cordierite can be used. The porosity of the main body 11 is not particularly limited, but can be 25% to 50%.

  The average pore diameter of the main body 11 is not particularly limited, but can be 0.1 μm to 50 μm. The average pore diameter of the main body 11 is preferably 1 μm or more, and more preferably 2.5 μm or more. Thereby, the pressure loss inside the main body 11 can be reduced. The average pore diameter of the main body 11 is preferably 30 μm or less, and more preferably 20 μm or less. As a result, the number of necking portions between the constituent material particles can be increased, so that the strength of the main body 11 can be improved. The average pore diameter of the main body 11 can be measured by a mercury intrusion method. The average particle diameter of the porous material constituting the main body 11 can be 1 μm to 100 μm. In the present embodiment, the “average particle diameter” is an arithmetic average value of the maximum diameters of 30 measurement target particles measured by cross-sectional microstructure observation using a scanning electron microscope (SEM).

  The main body 11 includes a first end surface 21, a second end surface 22, a side surface 23, a plurality of through holes 24, and a plurality of discharge channels 25. The first end surface 21 is provided on the opposite side of the second end surface 22. The side surface 23 continues to the outer edges of the first end surface 21 and the second end surface 22. Each of the plurality of through holes 24 penetrates the main body 11 from the first end surface 21 to the second end surface 22. Each of the plurality of through holes 24 is formed along the longitudinal direction of the main body 11. The inner diameter of each of the plurality of through holes 24 can be 1 mm to 5 mm.

  As shown in FIG. 2, the plurality of porous films 20 are formed inside some of the plurality of through holes 24. The porous film 20 is formed in a cylindrical shape. The inner diameter of the porous membrane 20 can be set to 0.5 mm to 5 mm, for example.

  The porous film 20 is a film formed through a film forming process using a filtration method. The filtration method may be used in a step of forming a film material, or may be used in a step of forming a seed crystal-containing material. Examples of such a porous membrane 20 include an MF membrane, a UF membrane, a gas separation membrane, a pervaporation membrane, and a vapor permeable membrane. Specific examples include ceramic membranes (for example, see JP-A-3-267129 and JP-A-2008-246304), carbon monoxide separation membranes (for example, see Japanese Patent No. 4006107), helium separation membranes (for example, Patent No. 3953833), hydrogen separation membrane (see, for example, Japanese Patent No. 3933907), carbon membrane (see, for example, JP-A-2003-286018), zeolite membrane (see, for example, JP-A-2004-66188) ), A silica film (see, for example, pamphlet of International Publication No. 2008/050812), an organic-inorganic hybrid silica film (Japanese Patent Laid-Open No. 2013-203618), and a p-tolyl group-containing silica film (Japanese Patent Laid-Open No. 2013-226541). Can be mentioned.

  FIG. 3 is a partially enlarged view of FIG. In FIG. 3, the cross section of the main-body part 11 and the porous membrane 20 is shown in figure. Since the porous film 20 is formed through a film forming process using a filtration method, the outer peripheral layer 20 a of the porous film 20 enters the inside of the main body 11. As a result, the outer peripheral layer 20 a of the porous film 20 forms a mixed layer with the main body 11. The average thickness of the porous film 20 and the average thickness of the outer peripheral layer 20a can be appropriately set according to the film type. Representative examples of the average thickness of the porous film 20 and the average thickness of the outer peripheral layer 20a are shown in Table 1 below, but are not limited thereto. In addition, the thickness of the porous film 20 includes the thickness of the outer peripheral layer 20a.

  As shown in FIG. 3, the porous film 20 formed by the filtration method is formed along the inner surface of the through hole 24. Thereby, since it is suppressed that the film thickness of the porous film 20 becomes thick locally in the recessed part of the inner surface of the through-hole 24, generation | occurrence | production of a crack can be suppressed. The surface roughness Ra on the surface 20S of the porous membrane 20 is 0.1 μm or more. The surface roughness Ra on the surface 20S is preferably 3.0 μm or less. Thereby, the fluid resistance of the mixed fluid with respect to the surface 20S can be reduced. The surface roughness Ra on the surface 20S can be measured by a method based on JIS B 0601-2001 from a 25 μm long cross-sectional curve obtained by SEM.

  In addition, when the porous film is formed by a film forming method other than the filtration method (for example, a flow-down method or a dip method), the surface roughness Ra of the porous film can be less than 0.1 μm, Since the thickness of the porous film locally increases in the concave portion on the inner surface of the through hole 24, cracks are likely to occur.

  Here, as shown in FIG. 2, the space inside the porous membrane 20 is a filtration cell Cf through which a liquid mixture or gas mixture (hereinafter referred to as “mixed fluid”) to be separated flows. Both ends of the filtration cell Cf are open to the first and second end faces 21 and 22. In the present embodiment, as shown in FIG. 1, a predetermined number of filtration cells Cf that form a row along a predetermined direction are formed in 12 rows.

  Moreover, as shown in FIG. 2, the space inside the through-hole 24 in which the porous membrane 20 is not formed among the plurality of through-holes 24 is a water collection cell Cw in which permeated components are collected. Both ends of the water collection cell Cw are sealed by the first and second plugs 12 and 13. Both ends of the water collection cell Cw are not open to the first and second end faces 21 and 22. In the present embodiment, as shown in FIG. 1, a predetermined number of water collecting cells Cw arranged in a predetermined direction are formed in three rows. The three rows of water collecting cells Cw are arranged so as to divide the twelve rows of filtration cells Cf into every three rows. The first and second pluggings 12 and 13 can be made of a porous material similar to that of the main body 11. The porosity of the first and second pluggings 12 and 13 is not particularly limited, but is preferably 25 to 50%. The filling depth of the first and second pluggings 12 and 13 is not particularly limited, but can be about 1 to 20 mm.

  Here, the inner surface 11S of the water collection cell Cw is an example of the “outflow surface” according to the present embodiment. The permeation component (for example, water vapor) contained in the mixed fluid flowing through the filtration cell Cf passes through the porous membrane 20 and then passes through the pores of the main body 11 to enter the water collection cell Cw from the inner surface 11S. It is divided into a flow that flows out and a flow that flows out directly from the side surface 23 of the main body 11. At this time, since the same negative pressure is generated on the inner surface 11S and the side surface 23, it can be said that the inner surface 11S and the side surface 23 have the same pressure field.

  Each of the plurality of discharge channels 25 penetrates the main body 11 from one side of the side surface 23 to the other side. Two discharge channels 25 are formed in one row of water collection cells Cw. Each of the two discharge flow paths 25 communicates with all the water collection cells Cw in one row. The two discharge flow paths 25 are separated in the longitudinal direction. The permeated component that has flowed into the water collection cell Cw flows out through the discharge channel 25 and through the opening formed in the side surface 23.

  The first seal portion 26 covers the entire first end surface 21 and a part of the side surface 23. The first seal portion 26 prevents the mixed fluid from infiltrating the first end surface 21. The first seal portion 26 is formed so as not to block the inlet of the filtration cell Cf. The first seal portion 26 covers the first plugging 12. As a material constituting the first seal portion 26, glass, metal, rubber, resin, or the like can be used. In consideration of consistency with the thermal expansion coefficient of the main body portion 11, glass is preferable.

  The second seal portion 27 covers the entire second end surface 22 and a part of the side surface 23. The second seal portion 27 suppresses the mixed fluid from infiltrating the second end surface 22. The second seal portion 27 is formed so as not to block the outlet of the filtration cell Cf. The second seal portion 27 covers the second plugging 13. The second seal portion 27 can be made of the same material as the first seal portion 26.

(Thickness of porous membrane 20)
Next, the thickness of the porous film 20 will be described with reference to the drawings. 4 is a cross-sectional view taken along line BB in FIG.

  In the following description, the three filtration cells Cf disposed between the two water collection cells Cw are sequentially referred to as “first filtration cell Cf1”, “second filtration cell Cf2”, and “third filtration cell Cf3”. Of the two water collection cells Cw, those adjacent to the first filtration cell Cf1 are referred to as “first water collection cells Cw1”, and those adjacent to the third filtration cell Cf3 are referred to as “second water collection cells Cw2”. Called.

  Further, the through hole 24 in which the first filtration cell Cf1 is disposed is referred to as “first through hole 241”, the through hole 24 in which the second filtration cell Cf2 is disposed is referred to as “second through hole 242”, and the third The through hole 24 in which the filtration cell Cf3 is disposed is referred to as a “third through hole 243”. The second through hole 242 is located between the first through hole 241 and the third through hole 243.

  Further, the porous membrane 20 formed on the inner surface of the first through-hole 241 and forming the first filtration cell Cf1 is referred to as “first porous membrane 201”, and is formed on the inner surface of the second through-hole 242. The porous membrane 20 forming the second filtration cell Cf2 is referred to as “second porous membrane 202”, and the porous membrane 20 formed on the inner surface of the third through-hole 243 and forming the third filtration cell Cf3 is “ This is referred to as the third porous membrane 203 ″.

  In the following description, the “average thickness” of the porous film 20 is the thickness measured 20 mm inside from one end of the porous film 20 in the longitudinal direction of the main body 11 (see FIG. 1), The arithmetic mean value of the thickness measured 20 mm inside from the other end and the thickness measured at the center in the longitudinal direction of the porous membrane 20 is meant.

  As shown in FIG. 4, the first porous membrane 201 has a first average thickness t1 on the first water collection cell Cw1 side, and a second average thickness t2 on the side opposite to the first water collection cell Cw1. The first average thickness t1 of the first porous membrane 201 is the thickness of the portion of the first porous membrane 201 that is closest to the inner surface 11S (that is, the outflow surface) of the first water collection cell Cw1. The second average thickness t2 of the first porous membrane 201 is the thickness of the portion of the first porous membrane 201 farthest from the first water collection cell Cw1.

  Each of the first average thickness t1 and the second average thickness t2 of the first porous film 201 can be appropriately set depending on the film type of the first porous film 201 (see Table 1). In the present embodiment, the ratio (t2 / t1) of the second average thickness t2 to the first average thickness t1 is 0.6 or more. That is, the second average thickness t2 is not less than 0.6 times the first average thickness t1. Thereby, when the mixed fluid is circulated through the first filtration cell Cf1, it is possible to prevent the load from being concentrated on the portion of the first porous membrane 201 farthest from the first water collection cell Cw1 and causing damage. The ratio of the second average thickness t2 to the first average thickness t1 (t2 / t1) is preferably 0.7 or more, and more preferably 0.9 or more. Further, the second average thickness t2 may be equal to the first average thickness t1, or may be larger than the first average thickness t1.

  As shown in FIG. 4, the second porous membrane 202 has a third average thickness t3 on the first water collection cell Cw1 side. The third average thickness t3 of the second porous membrane 202 is the thickness of the portion of the second porous membrane 202 that is closest to the inner surface 11S of the first water collection cell Cw1.

  The third average thickness t3 of the second porous film 202 can be appropriately set depending on the film type of the second porous film 202 (see Table 1). In the present embodiment, the ratio (t3 / t1) of the third average thickness t3 of the second porous membrane 202 to the first average thickness t1 of the first porous membrane 201 is 0.6 or more. That is, the third average thickness t3 of the second porous film 202 is 0.6 times or more the first average thickness t1 of the first porous film 201. As a result, when the mixed fluid is circulated through the second filtration cell Cf2, it is possible to prevent the load from concentrating on the portion close to the first water collection cell Cw1 in the second porous membrane 202 and causing damage. It is possible to suppress a difference between the durability of the first porous film 201 and the durability of the second porous film 202. The ratio (t3 / t1) of the third average thickness t3 of the second porous membrane 202 to the first average thickness t1 of the first porous membrane 201 is preferably 0.7 or more, and is 0.9 or more. More preferably. Further, the third average thickness t3 may be equal to the first average thickness t1, or may be larger than the first average thickness t1.

  The second porous membrane 202 has a fourth average thickness t4 on the side opposite to the first water collection cell Cw1. The fourth average thickness t4 of the second porous membrane 202 is the thickness of the portion of the second porous membrane 202 farthest from the inner surface 11S of the first water collection cell Cw1.

  The fourth average thickness t4 of the second porous membrane 202 can be appropriately set depending on the type of the second porous membrane 202 (see Table 1). In the present embodiment, the ratio (t4 / t1) of the fourth average thickness t4 of the second porous membrane 202 to the first average thickness t1 of the first porous membrane 201 is 0.6 or more. That is, the fourth average thickness t4 of the second porous membrane 202 is 0.6 times or more the first average thickness t1 of the first porous membrane 201. As a result, when the mixed fluid is circulated through the second filtration cell Cf2, it is possible to suppress the load from being concentrated on the portion of the second porous membrane 202 away from the first water collection cell Cw1 to cause damage. It is possible to further suppress the difference between the durability of the first porous film 201 and the durability of the second porous film 202. The ratio (t4 / t1) of the fourth average thickness t4 of the second porous membrane 202 to the first average thickness t1 of the first porous membrane 201 is preferably 0.7 or more, and is 0.9 or more. More preferably. Further, the fourth average thickness t4 may be equal to the first average thickness t1, or may be larger than the first average thickness t1. The ratio of the fourth average thickness t4 to the third average thickness t3 (t4 / t3) is preferably 0.6 or more, more preferably 0.7 or more, and 0.9 or more. Is particularly preferred. The fourth average thickness t4 may be equal to the third average thickness t3, or may be greater than the third average thickness t3.

  As shown in FIG. 4, the first porous membrane 201 has a fifth average thickness t5 at the center when the first water collection cell Cw1 is used as a reference. The fifth average thickness t5 of the first porous membrane 201 is the thickness between the portion of the first porous membrane 201 close to the inner surface 11S of the first water collection cell Cw1 and the portion away from the first water collection cell Cw1. It is.

  The fifth average thickness t5 of the first porous film 201 can be appropriately set depending on the film type of the first porous film 201 (see Table 1). The ratio (t5 / t1) of the fifth average thickness t5 to the first average thickness t1 of the first porous membrane 201 is preferably 0.6 or more, more preferably 0.7 or more, and It is particularly preferable that the number is 9 or more. Thereby, the durability of the first porous film 201 can be further improved.

  As shown in FIG. 4, the second porous membrane 202 has a sixth average thickness t6 at the center when the first water collection cell Cw1 is used as a reference. The sixth average thickness t6 of the second porous membrane 202 is a thickness between a portion of the second porous membrane 202 close to the inner surface 11S of the first water collection cell Cw1 and a portion away from the first water collection cell Cw1. It is.

  The sixth average thickness t6 of the second porous film 202 can be appropriately set depending on the film type of the second porous film 202 (see Table 1). The ratio (t6 / t1) of the sixth average thickness t6 to the first average thickness t1 of the first porous membrane 201 is preferably 0.6 or more, more preferably 0.7 or more, and It is particularly preferable that the number is 9 or more. Thereby, the durability of the second porous film 201 can be further improved. Further, the ratio (t6 / t5) of the sixth average thickness t6 to the fifth average thickness t5 of the second porous membrane 202 is preferably 0.6 or more, more preferably 0.7 or more, It is especially preferable that it is 0.9 or more.

  In addition, as shown in FIG. 4, the space | interval L1 of the 1st through-hole 241 and the inner surface 11S of the water collection cell Cw can be 5 micrometers-1500 micrometers. The interval L1 is preferably 50 μm or more, and more preferably 250 μm or more. Thus, when the first porous film 201 is formed by the filtration film formation method, it is possible to suppress the clogging of the porous material between the first through-hole 241 and the water collection cell Cw. The film thickness uniformity can be improved. The space | interval L1 is the thickness of the part pinched | interposed into 1st water collection cell Cw1 and 1st filtration cell Cf1 among the main-body parts 11. FIG.

  Further, the distance L2 between the first through hole 241 and the second through hole 242 can be set to 5 μm to 1500 μm. The interval L2 is preferably 50 μm or more, and more preferably 250 μm or more. Accordingly, when the second porous film 202 is formed by the filtration film formation method, it is possible to suppress the clogging of the porous material between the first through hole 241 and the second through hole 242, and thus the second porous film The uniformity of the film thickness of 202 can be improved. The interval L2 is the thickness of the portion of the main body 11 that is sandwiched between the first filtration cell Cf1 and the second filtration cell Cf2.

(Manufacturing method of monolithic separation membrane structure 100)
Next, the manufacturing method of the monolith type separation membrane structure 100 will be described. Hereinafter, a case where an MF film or a UF film is formed as the porous film 20 will be described as an example.

  First, a porous material is prepared, and a molded body of the main body 11 having a plurality of through holes 24 is formed. As a method for forming a molded body, a press molding method or a cast molding method can be used in addition to an extrusion molding method using a vacuum extrusion molding machine.

  Next, the discharge channel 25 is formed in the molded body of the main body 11 using a sharp jig.

  Next, an organic binder, a sintering aid, a pH adjuster, a surfactant, and the like are added to the porous material to prepare a plugging slurry.

  Next, a film of polyester or the like is attached to both end faces of the molded body of the main body portion 11, and holes are formed in portions corresponding to the through holes 24 that form the water collecting cells Cw among the plurality of through holes 24.

  Next, the molded body of the 1st and 2nd pluggings 12 and 13 is formed by pressing the both ends of the molded body of the main body part 11 against the plugging slurry.

  Next, the molded body of the main body portion 11 and the molded bodies of the first and second pluggings 12 and 13 are fired (for example, 500 ° C. to 1500 ° C., 0.5 hours to 80 hours) to form a monolith type substrate. 10 is formed. A water collection cell Cw is formed between the first and second pluggings 12 and 13. The average pore diameter of the main body 11 can be 0.1 μm to 50 μm, and preferably 1 μm or more. The distances L1 and L2 (see FIG. 4) between the through holes 24 can be 5 μm to 1500 μm, preferably 50 μm or more, and more preferably 250 μm or more.

  Next, a first porous material containing particles having a particle size of 1/3 or less of the average pore diameter of the main body 11 (hereinafter referred to as “small particles”) at a frequency of 40% or more and 60% or less, and the main body A second porous material containing particles having a particle size equal to or larger than the average pore size of the portion 11 (hereinafter referred to as “large particles”) at a frequency of 40% to 70% is prepared.

  Next, a filtration resistance agent and water are added to the first porous material to produce a slurry for the first porous membrane, and a filtration resistance agent and water are added to the second porous material to obtain a second porous membrane. A slurry is prepared. And the slurry for porous membranes is prepared by mixing the slurry for 1st porous membranes, and the slurry for 2nd porous membranes. At this time, in the slurry for a porous membrane, it is preferable to adjust the frequency of large particles to a range of 2 to 8 times the frequency of small particles.

  Next, a molded body of the porous film 20 is formed on the inner surface of the through hole 24 not sealed by the first and second pluggings 12 and 13 by a filtration film forming method using the slurry for the porous film. Form. Specifically, the porous material is deposited on the inner surface of the through hole 24 by evacuating the outer periphery of the main body 11 while circulating the slurry for the porous film through the through hole 24. As described above, since small particles and large particles are mixed in a well-balanced manner in the slurry for the porous membrane, it is possible to suppress the occurrence of non-uniform negative pressure on the inner surface of the through hole 24. Accordingly, as described with reference to FIG. 4, the ratio (t2 / t1) of the second average thickness t2 to the first average thickness t1 of the first porous film 201 can be 0.6 or more.

  Further, when it is desired to independently adjust the third average thickness t3 of the second porous membrane 202, the following method can be used. First, the opening at both ends of the first filtration cell Cf1 and the third filtration cell Cf3 is closed with tape or the like, and the opening at both ends of the discharge channel 25 penetrating the second water collection cell Cw2 is closed with tape or the like. Next, the outer periphery of the main body 11 is evacuated while circulating the slurry for the porous membrane through the second filtration cell Cf2. Accordingly, since the porous material is deposited only on the first water collection cell Cw1 side in the second through hole 242, the third average thickness t3 of the second porous film 202 can be increased.

  Similarly, when it is desired to independently adjust the fourth average thickness t4 of the second porous membrane 202, the following method can be used. First, both end openings of the first filtration cell Cf1 and the third filtration cell Cf3 are closed with a tape or the like, and both end openings of the discharge channel 25 penetrating the first water collection cell Cw1 are closed with a tape or the like. Next, the outer periphery of the main body 11 is evacuated while circulating the slurry for the porous membrane through the second filtration cell Cf2. Accordingly, since the porous material is deposited only on the second water collection cell Cw2 side in the second through hole 242, the fourth average thickness t4 of the second porous film 202 can be increased.

  Next, the porous membrane 20 is formed by firing the molded body of the porous membrane 20 (for example, 500 ° C. to 1450 ° C., 0.5 hours to 80 hours).

  Next, water and an organic binder are mixed in a glass frit to prepare a slurry for glass sealing.

  Next, slurry for glass sealing is applied to the first end surface 21 and the second end surface 22 of the main body 11 to form molded bodies of the first and second seal portions 26 and 27. Subsequently, the molded bodies of the first and second seal portions 26 and 27 are fired (800 to 1000 ° C., 1 hour to 100 hours) to form the first and second seal portions 26 and 27.

2. Second Embodiment (Configuration of Separation Membrane Structure 101)
FIG. 5 is a perspective view of the separation membrane structure 101. 6 is a cross-sectional view taken along line FF in FIG.

  The separation membrane structure 101 includes a monolithic substrate 30, a plurality of porous membranes 40, a first seal portion 32, and a second seal portion 33.

  The monolithic substrate 30 is a rod-like member that extends in the longitudinal direction about the central axis AX.

  The monolith type substrate 30 is made of a porous material. As the porous material of the monolith type substrate 30, the same material as that of the main body 11 according to the first embodiment can be used. The monolithic base material 30 has a first end surface 41, a second end surface 42, a side surface 43, and a plurality of through holes 44. The side surface 43 is an example of an “outflow surface” according to the present embodiment. A permeation component (for example, water vapor) contained in a mixed fluid flowing through a filtration cell Cf, which will be described later, passes through the porous membrane 40, then passes through the pores of the monolith substrate 30 and directly flows out from the side surface 23 to the outside. To do.

  The configurations of the first seal portion 32 and the second seal portion 33 are the same as those of the first seal portion 26 and the second seal portion 27 according to the first embodiment.

  As shown in FIG. 6, the plurality of porous films 40 are formed inside all the through holes 44. The porous film 40 is formed in a cylindrical shape. The porous film 40 may be a film formed through a film forming process using a filtration method. As a specific example of the porous film 40, a film similar to the porous film 20 according to the first embodiment can be used. The space inside the porous membrane 40 is a filtration cell Cf through which the mixed fluid to be separated flows. Both ends of the filtration cell Cf open to the first and second end faces 41 and 42.

  The porous film 40 formed by the filtration method is formed along the inner surface of the through hole 44. The surface roughness Ra on the surface of the porous membrane 40 is not particularly limited, but can be 0.1 μm or more, and preferably 3.0 μm or less. The surface roughness Ra can be measured by a technique based on JIS B 0601-2001 from a 25 μm long cross-sectional curve obtained by SEM.

(Thickness of porous film 40)
Next, the thickness of the porous film 40 will be described with reference to the drawings. FIG. 7 is a partially enlarged view of FIG.

  In the following description, the two filtration cells Cf arranged in this order from the side surface 43 side are referred to as “first filtration cell Cf1” and “second filtration cell Cf2”. Further, the through hole 44 in which the first filtration cell Cf1 is disposed is referred to as “first through hole 441”, and the through hole 44 in which the second filtration cell Cf2 is disposed is referred to as “second through hole 442”.

  The porous film 40 formed on the inner surface of the first through hole 441 and forming the first filtration cell Cf1 is referred to as “first porous film 401”, and is formed on the inner surface of the second through hole 442. The porous membrane 40 forming the two filtration cell Cf2 is referred to as a “second porous membrane 402”.

  In the following description, the “average thickness” of the porous film 40 means the thickness measured 20 mm inside from one end of the porous film 40 in the longitudinal direction of the monolithic substrate 30 (see FIG. 5), and the porous film. The arithmetic mean value of the thickness measured 20 mm inside from the other end of 40 and the thickness measured at the center in the longitudinal direction of the porous membrane 40 is meant.

  As shown in FIG. 7, the first porous membrane 401 has a first average thickness s1 on the side surface 43 side and a second average thickness s2 on the side opposite to the side surface 43. The first average thickness s1 of the first porous membrane 401 is the thickness of the portion of the first porous membrane 401 that is closest to the side surface 43 (that is, the outflow surface). The second average thickness s2 of the first porous membrane 401 is the thickness of the portion of the first porous membrane 401 that is farthest from the side surface 43.

  Each of the first average thickness s1 and the second average thickness s2 of the first porous film 401 can be appropriately set depending on the film type of the first porous film 401 (see Table 1). In the present embodiment, the ratio (s2 / s1) of the second average thickness s2 to the first average thickness s1 is 0.6 or more. That is, the second average thickness s2 is not less than 0.6 times the first average thickness s1. Thereby, when the mixed fluid is circulated through the first filtration cell Cf1, it is possible to suppress the load from being concentrated on the portion of the first porous membrane 401 farthest from the side surface 43 and causing damage. The ratio (s2 / s1) of the second average thickness s2 to the first average thickness s1 is preferably 0.7 or more, and more preferably 0.9 or more. Further, the second average thickness s2 may be equal to the first average thickness s1, or may be larger than the first average thickness s1.

  As shown in FIG. 7, the second porous membrane 402 has a third average thickness s3 on the side surface 43 side. The third average thickness s3 of the second porous membrane 402 is the thickness of the portion of the second porous membrane 402 that is closest to the side surface 43.

  The third average thickness s3 of the second porous film 402 can be appropriately set depending on the film type of the second porous film 402 (see Table 1). In the present embodiment, the ratio (s3 / s1) of the third average thickness s3 of the second porous membrane 402 to the first average thickness s1 of the first porous membrane 401 is 0.6 or more. That is, the third average thickness s3 of the second porous membrane 402 is 0.6 times or more the first average thickness s1 of the first porous membrane 401. Thus, when the mixed fluid is circulated through the second filtration cell Cf2, it is possible to prevent the load from concentrating on the portion close to the side surface 43 of the second porous membrane 402 and causing damage, so that the first porous membrane It is possible to suppress a difference between the durability of 401 and the durability of the second porous film 402. The ratio (s3 / s1) of the third average thickness s3 of the second porous membrane 402 to the first average thickness s1 of the first porous membrane 401 is preferably 0.7 or more, and is 0.9 or more. More preferably. Further, the third average thickness s3 may be equal to the first average thickness s1, or may be larger than the first average thickness s1.

  The second porous membrane 402 has a fourth average thickness s4 on the side opposite to the side surface 43. The fourth average thickness s4 of the second porous film 402 is the thickness of the portion of the second porous film 402 farthest from the side surface 43.

  The fourth average thickness s4 of the second porous film 402 can be appropriately set depending on the film type of the second porous film 402 (see Table 1). In the present embodiment, the ratio (s4 / s1) of the fourth average thickness s4 of the second porous membrane 402 to the first average thickness s1 of the first porous membrane 401 is 0.6 or more. That is, the fourth average thickness s4 of the second porous film 402 is 0.6 times or more the first average thickness s1 of the first porous film 401. Thus, when the mixed fluid is circulated through the second filtration cell Cf2, it is possible to prevent the load from being concentrated on the portion of the second porous membrane 402 away from the side surface 43 and causing damage. A difference between the durability of the membrane 401 and the durability of the second porous membrane 402 can be further suppressed. The ratio (s4 / s1) of the fourth average thickness s4 of the second porous membrane 402 to the first average thickness s1 of the first porous membrane 401 is preferably 0.7 or more, and preferably 0.9 or more. More preferably. Further, the fourth average thickness s4 may be equal to the first average thickness s1, or may be larger than the first average thickness s1. The ratio of the fourth average thickness s4 to the third average thickness s3 (s4 / s3) is preferably 0.6 or more, more preferably 0.7 or more, and 0.9 or more. Is particularly preferred. The fourth average thickness s4 may be equal to or greater than the third average thickness s3.

  As shown in FIG. 7, the first porous membrane 401 has a fifth average thickness s <b> 5 at the central portion when the side surface 43 is used as a reference. The fifth average thickness s5 of the first porous membrane 401 is a thickness between a portion near the side surface 43 and a portion away from the side surface 43 in the first porous membrane 401.

  The fifth average thickness s5 of the first porous film 401 can be appropriately set depending on the film type of the first porous film 401 (see Table 1). The ratio (s5 / s1) of the fifth average thickness s5 to the first average thickness s1 of the first porous membrane 401 is preferably 0.6 or more, more preferably 0.7 or more, and It is particularly preferable that the number is 9 or more. Thereby, the durability of the first porous membrane 401 can be further improved.

  As shown in FIG. 7, the second porous film 402 has a sixth average thickness s <b> 6 at the center when the side surface 43 is used as a reference. The sixth average thickness s6 of the second porous membrane 402 is a thickness between a portion close to the side surface 43 and a portion away from the side surface 43 in the second porous membrane 402.

  The sixth average thickness s6 of the second porous film 402 can be appropriately set depending on the film type of the second porous film 402 (see Table 1). The ratio (s6 / s1) of the sixth average thickness s6 to the first average thickness s1 of the first porous membrane 401 is preferably 0.6 or more, more preferably 0.7 or more, and It is particularly preferable that the number is 9 or more. Thereby, the durability of the second porous membrane 401 can be further improved. The ratio (s6 / s5) of the sixth average thickness s6 to the fifth average thickness s5 of the second porous membrane 402 is preferably 0.6 or more, more preferably 0.7 or more, It is especially preferable that it is 0.9 or more.

  In addition, as shown in FIG. 7, the space | interval M1 of the 1st through-hole 441 and the side surface 43 can be 5 micrometers-1500 micrometers. The interval L1 is preferably 50 μm or more, and more preferably 250 μm or more. The interval L1 is the thickness of the portion of the monolithic substrate 30 outside the first filtration cell Cf1.

  Further, the interval M2 between the first through hole 441 and the second through hole 442 can be set to 5 μm to 1500 μm. The interval M2 is preferably 50 μm or more, and more preferably 250 μm or more. The interval M2 is the thickness of the portion sandwiched between the first filtration cell Cf1 and the second filtration cell Cf2 in the monolithic substrate 30.

(Manufacturing method of the separation membrane structure 101)
The manufacturing method of the separation membrane structure 101 is the same as that of the separation membrane structure 100 according to the first embodiment except that the porous membrane 40 is formed inside all the through holes 44 without forming a water collection cell. This is the same as the manufacturing method.

  Note that the third average thickness s3 of the second porous membrane 402 can be independently controlled by performing the filtration film formation method in a state in which both end openings of the first filtration cell Cf1 are closed.

  In addition, the fourth average thickness s4 of the second porous membrane 402 is set so that the second filtration cell Cf2 is placed in the horizontal direction so that the second filtration cell Cf2 is positioned vertically below the first filtration cell Cf1. It can be controlled independently by carrying out the filtration film forming method while supplying the slurry for the porous film to about half the height of the cell Cf2.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

  In the above embodiment, the inner diameters of the plurality of through holes 24 are all equal, but the present invention is not limited to this. For example, the inner diameter may be different between the through hole 24 in which the filtration cell Cf is formed and the through hole 24 in which the water collection cell Cw is formed.

  In the first embodiment, the monolithic separation membrane structure 100 includes 12 rows of filtration cells Cf and 3 rows of water collection cells Cw, and 3 rows of filtration cells Cf between the 2 rows of water collection cells Cw. The arrangement is not limited to this. The number of the filtration cells Cf arranged between the two water collection cells Cw is not particularly limited and may be one or more. However, the through-hole 24 when the porous membrane 20 is formed by filtration. In order to suppress the negative pressure difference between the inner and the through holes 24, it is preferably 10 rows or less, more preferably 6 rows or less. The arrangement | sequence and number of each of the filtration cell Cf and the water collection cell Cw can be changed suitably. For example, the monolith type separation membrane structure 100 includes 28 rows of filtration cells Cf and 5 rows of water collection cells Cw, and 4 rows of filtration cells Cf are arranged between 2 rows of water collection cells Cw. preferable. The number of filtration cells Cf arranged in a row is preferably 1 to 31, and the number of water collecting cells Cw arranged in a row is preferably 2 to 16.

  In the first embodiment, two drain passages 25 are provided in one water collection cell Cw, but the number and positions of the drain passages 25 can be changed as appropriate.

  In the first embodiment, each of the first and second seal portions 26 and 27 covers a part of the side surface 23, but may not cover the side surface 23.

  In the first embodiment, the thickness relationship of the porous membrane 20 based on the position of the water collection cell Cw has been described with reference to FIGS. 4 to 7, but this thickness relationship is related to all the porous membranes. Of these, it is preferable that 60% or more of the porous film 20 is formed, and 80% or more of the porous film 20 is more preferable.

  In the first embodiment, the porous film 20 is formed directly on the inner surface of the through hole 24, but is not limited thereto. The monolithic substrate 10 according to the first embodiment may have an intermediate layer disposed between the main body 11 and the porous membrane 20. Such an intermediate layer can be formed of a porous material similar to that of the main body portion 11. The average pore diameter of the intermediate layer may be smaller than the average pore diameter of the main body 11, but is preferably 2.5 μm or more. Moreover, when forming an intermediate | middle layer by the filtration method, it is preferable that the relationship of the thickness ratio similar to the porous membrane 20 which concerns on the said 1st Embodiment is materialized. Similarly, in the second embodiment, an intermediate layer may be disposed between the monolithic substrate 30 and the porous membrane 40.

  Hereinafter, examples of the monolith type substrate according to the present invention will be described. However, the present invention is not limited to the examples described below.

(Production of sample No. 1 to No. 15)
Sample no. 1-No. A monolithic separation membrane structure according to No. 15 was produced.

  First, 20 parts by mass of an inorganic binder was added to 100 parts by mass of alumina, and further, water, a dispersant and a thickener were added and kneaded to prepare a porous material.

  Next, the molded body of the main body having a plurality of through holes was formed by extruding the adjusted porous material. By changing the die of the extrusion molding machine, the distances (L1, L2) of the plurality of through holes were changed as shown in Table 2.

  Next, a discharge channel was formed in the molded body of the support using a sharp jig.

  Next, an organic binder, a sintering aid, a pH adjuster, a surfactant and the like were added to the plugging porous material to prepare a plugging slurry.

  Next, a polyester film was affixed to both end faces of the molded body of the main body portion, and holes were formed in portions corresponding to the through holes forming the water collection cell among the plurality of through holes.

  Next, a pair of plugged molded bodies were formed by pressing both ends of the molded body of the main body against the plugging slurry.

  Next, the molded body of the main body part and the molded body of the plugging were fired (1250 ° C., 1 hour) to produce a monolith type substrate. The basic configuration of the monolith type substrate was as described with reference to FIGS. The distance between the water collection cell and the filtration cell adjacent to the water collection cell was as shown in Table 2. The “interval between the water collection cell and the filtration cell” shown in Table 2 is the “interval L1 between the first through hole 241 and the inner surface 11S (ie, the outflow surface) of the water collection cell Cw” shown in FIG. The same. Table 2 shows the average pore diameter of the main body measured by mercury porosimetry.

  Next, a first porous material containing small particles having a particle size of 1/3 or less of the average pore diameter of the main body part at a frequency of 50%, and large particles having a particle diameter equal to or larger than the average pore diameter of the main body part A second porous material containing at a frequency of 60% was prepared. D10 of the first porous material was 0.5 μm, D50 was 1.1 μm, and D90 was 2.1 μm. D10 of the second porous material was 1.2 μm, D50 was 4.1 μm, and D90 was 11.8 μm.

  Next, a first porous membrane slurry was prepared by mixing a first porous material containing small particles at a frequency of 50%, a filtration resistance agent (organic polymer), and water. Similarly, a second porous membrane slurry was prepared by mixing a second porous material containing large particles at a frequency of 60%, a filtration resistance agent (organic polymer), and water.

  Next, the slurry for porous membranes was prepared by mixing the slurry for 1st porous membranes and the slurry for 2nd porous membranes. At this time, by changing the weight ratio of the first porous membrane slurry and the second porous membrane slurry for each sample, the frequency of small particles and large particles in the porous membrane slurry is as shown in Table 1. It was adjusted. Sample No. In No. 1, the first porous membrane slurry containing 50% of small particles and the second porous membrane slurry containing 60% of large particles were mixed at a weight ratio of 1: 7. Therefore, the frequency of small particles in the slurry for porous membrane is 50% × (1 / (1 + 7)) = 6.3%, and the frequency of large particles in the slurry for porous membrane is 60% × (7 / (1 + 7)) = 52.5%. Therefore, sample no. In the porous membrane slurry used in No. 1, the frequency of large particles was 8.3 times that of small particles. Sample No. In the slurry for a porous membrane used in No. 2, the frequency of large particles was 1.2 times that of small particles. Sample No. In the porous membrane slurry used in 3-8 and 10-15, the frequency of large particles was 3.6 times that of small particles. Sample No. In the slurry for a porous membrane used in No. 9, the frequency of large particles was 0.4 times that of small particles.

  Next, a molded body of the porous film was formed on the inner surface of the through hole not sealed by the first and second pluggings by a filtration film forming method using the slurry for the porous film. Specifically, the porous material was deposited on the inner surface of the through hole by evacuating the outer periphery of the main body while circulating the slurry for the porous membrane through the through hole. At this time, as shown in FIG. 4, in the first porous membrane 201 formed in the first filtration cell Cf1 adjacent to the water collection cell, the ratio of the second average thickness t2 to the first average thickness t1 (t2 / t1) was adjusted according to the frequency of small particles and large particles contained in the slurry for the porous membrane.

  Next, sample no. 2, 5, 7, 8, as shown in FIG. 4, the second porous membrane 202 of the second porous membrane 202 formed in the second filtration cell Cf 2 located in the center of the first and second water collection cells Cw 1, Cw 2. 3 The average thickness t3 was adjusted independently. Specifically, the both end openings of the first filtration cell Cf1 and the third filtration cell Cf3 are closed with tape, and the both end openings of the discharge channel 25 penetrating the second water collection cell Cw2 are covered with tape. 2 The outer periphery of the main body 11 was evacuated while circulating the slurry for the porous membrane through the filtration cell Cf2. Thereby, the third average thickness t3 of the two porous membranes 202 was increased by depositing the porous material only on the first water collection cell Cw1 side in the second through holes 242.

  Next, sample no. In 2 and 6 to 8, as shown in FIG. 4, the fourth average thickness t4 of the second porous film 202 was independently adjusted. Specifically, the both end openings of the first filtration cell Cf1 and the third filtration cell Cf3 are closed with a tape or the like, and the both end openings of the discharge channel 25 penetrating the first water collection cell Cw1 are covered with a tape, The outer periphery of the main body 11 was evacuated while circulating the slurry for the porous membrane through the second filtration cell Cf2. Thus, the fourth average thickness t4 of the second porous membrane 202 was increased by depositing the porous material only on the second water collection cell Cw2 side of the second through-hole 242.

  Next, the molded body of the porous film was fired (950 ° C., 3 hours) to form a porous film.

(Measurement of porous membrane thickness)
Sample No. 1-No. 15, the first to sixth thicknesses t1 to t4 of the porous membrane (see FIG. 4) in three cross-sections in total, ie, two locations 20 mm inside from the both ends in the longitudinal direction of the monolithic separation membrane structure and one center. ) Was measured. The measurement results are summarized in Table 2.

(Measurement of internal pressure fracture strength)
The monolithic separation membrane structure is housed in a cylindrical housing having a fluid inlet and a fluid outlet, and the internal pressure fracture strength at which the monolithic separation membrane structure is destroyed by being pressurized with water flowing from the fluid inlet is investigated. It was. When water permeated and the pressure did not increase, natural latex rubber was coated on the inner surface of the filtration cell and dried to prevent water permeation. The measurement results are shown in Table 2.

  As shown in Table 2, a sample in which the ratio (t2 / t1) of the second average thickness t2 to the first average thickness t1 in the porous membrane forming the first filtration cell adjacent to the water collection cell was 0.6 or more Then, an internal pressure fracture strength of 10 MPa or more could be obtained. This is because the concentration of the load on a part of the porous membrane can be suppressed by increasing the second average thickness t2 that tends to be the thinnest when the filtration film forming method is used.

  Sample No. As can be seen by comparing 3 and 4, in the porous membrane forming the first filtration cell adjacent to the water collection cell, the ratio of the second average thickness t2 to the first average thickness t1 (t2 / t1) is 0.7. In the sample described above, the internal pressure fracture strength could be improved.

  Sample No. 3 and 5, in the porous membrane forming the second filtration cell adjacent to the first filtration cell, the ratio (t3 / t1) of the third average thickness t3 to the first average thickness t1 is 0. The internal pressure breaking strength could be improved in the samples of 6 or more.

  Sample No. 3 and 6, in the porous membrane forming the second filtration cell adjacent to the first filtration cell, the ratio of the fourth average thickness t4 to the first average thickness t1 (t4 / t1) is set to 0. The internal pressure breaking strength could be improved in the samples of 6 or more.

  Further, it was confirmed that the internal pressure fracture strength can be further improved by setting each of t2 / t1, t3 / t1, and t4 / t1 to be 0.6 or more. Furthermore, it was confirmed that the internal pressure fracture strength can be particularly improved by setting each of t2 / t1, t3 / t1, and t4 / t1 to 0.7 or more.

  Sample No. As can be seen by comparing 10 to 12, it was found that the internal pressure breaking strength can be further improved by setting the distance between the filtration cell and the water collection cell to 250 μm or more.

  Sample No. As can be seen by comparing 13 to 15, it was found that the internal pressure fracture strength can be further improved by setting the average pore diameter of the substrate to 2.5 μm or more.

DESCRIPTION OF SYMBOLS 100,101 Monolith type separation membrane structure 10,30 Monolith type base material 11 Main body part 12 First plugging 13 Second plugging 15,33 Second seal part 20,40 Porous membranes 21,41 First end face 22, 42 Second end face 23, 43 Side face 24.44 Through hole 25 Discharge flow path Cf Filtration cell Cw Water collection cell

Claims (8)

A monolithic separation membrane structure for separating a permeate component from a mixed fluid,
A monolith type substrate having a plurality of through holes including a first through hole adjacent to an outflow surface from which the permeation component flows out;
A plurality of porous membranes including a first porous membrane formed inside the first through hole;
With
Wherein for the first average thickness of the outflow side of the first porous membrane, the ratio of the opposite side of the second average thickness and the outflow surface of the first porous film state, and are 0.6 or more,
The first average thickness is greater than the second average thickness;
Monolith type separation membrane structure. The plurality of through holes include a second through hole that is further away from the outflow surface than the first through hole,
The plurality of porous membranes include a second porous membrane formed inside the second through hole,
The ratio of the third average thickness on the outflow surface side of the second porous membrane to the first average thickness is 0.6 or more.
The monolith type separation membrane structure according to claim 1. The ratio of the fourth average thickness on the opposite side of the outflow surface of the second porous membrane to the first average thickness is 0.6 or more.
The monolith type separation membrane structure according to claim 2. The ratio of the second average thickness to the first average thickness is 0.7 or more.
The monolith type separation membrane structure according to any one of claims 1 to 3. The distance between the first through hole and the outflow surface is 250 μm or more.
The monolith type separation membrane structure according to any one of claims 1 to 4. The monolithic substrate has an average pore diameter of 2.5 μm or more.
The monolith type separation membrane structure according to any one of claims 1 to 5. A method for producing a monolithic separation membrane structure for separating a permeate component from a mixed fluid, comprising:
Forming a monolithic substrate having a through hole adjacent to an outflow surface from which the permeating component flows out;
By a filtration film forming method using a slurry for a porous membrane containing small particles having a particle size of 1/3 or less of the average pore size of the monolithic substrate and large particles having a particle size of the average pore size or more Forming a porous film inside the through hole;
With
In the slurry for the porous membrane, the frequency of the large particles, Ri 8 times der less than twice the frequency of the small particles,
Each of the small particles and the large particles is a porous material constituting the monolith substrate.
Manufacturing method of monolith type separation membrane structure. In the step of forming the porous membrane, a first slurry for a porous membrane prepared using a first porous material containing the small particles at a frequency of 40% or more and 60% or less, and 40% of the large particles Preparing the porous membrane slurry by mixing with the second porous membrane slurry prepared using the second porous material containing at a frequency of 70% or less,
The manufacturing method of the monolith type separation membrane structure of Claim 7.

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