Filtration vessel, membrane filtration vessel, membrane evaluation vessel, membrane filtration system, and membrane evaluation system

Abstract

Provided is a membrane evaluation vessel (400A) that is to be used in a membrane evaluation system that measures the performance of a separation membrane (460). The membrane evaluation vessel (400A) comprises a polyether ether ketone or polyphenylene ketone sulfide vessel (400) in which the separation membrane (460) is placed, a porous support plate (470) that has a plurality of through holes (471) and supports the separation membrane (460), and a support component (430) that supports the porous support plate (470). The vessel (400) includes a first channel (413) for supplying a testing solution into the vessel (400) and a second channel (486) for discharging the testing solution. The testing solution is supplied through the first channel (413) on one side of the separation membrane (460), and a transmitted liquid that is transmitted on the other side of the separation membrane (460) is discharged through the second channel (486).

Description

Filtration vessel, membrane filtration vessel, membrane evaluation vessel, membrane filtration system, and membrane evaluation system

[0001] The present disclosure relates to a filtration vessel that performs filtration using a separation membrane, a membrane filtration vessel, a membrane evaluation vessel, a membrane filtration system, and a membrane evaluation system.

[0002] Membrane separation is now being used in a variety of fields, including pharmaceuticals, beverages, and seawater desalination. Before using it in each field, it is important to understand the performance of the separation membrane using the solution to be treated (also called a model solution).

[0003] In addition, filtration methods using separation membranes have recently been used in various fields, for example, in wastewater treatment. JP 2022-165328 A (Patent Document 1) discloses a filtration vessel using a separation membrane.

[0004] Furthermore, Patent Document 1 discloses a membrane filtration system for measuring the performance of a separation membrane, in which a separation membrane is cut into a circular shape, placed in a container, and liquid is filtered through the membrane. A magnetic stirrer is built in to prevent damage to the membrane and the generation of impurities.

[0005] Japanese Patent Application Laid-Open No. 2022-165328

[0006] However, in the membrane filtration system disclosed in Patent Document 1, the container is made of stainless steel, and therefore there is a concern that it may be corroded by an aqueous solution containing an acid or alkali or an organic solvent, which may result in impurities being mixed into the concentrated liquid or permeate after filtration.

[0007] Generally, when measuring the performance of a separation membrane under high-pressure conditions, the separation membrane is set on a metal sintered filter in a membrane evaluation vessel (membrane evaluation cell) and is designed to prevent the membrane from sinking into the permeate flow path due to the test pressure. However, due to concerns about corrosion under acidic and alkaline conditions, it is necessary to replace the membrane with a resin sintered plate, but resin sintered plates may crack or warp under pressure.

[0008] (Problem of the Second Aspect) When a liquid to be treated is filtered using a separation membrane, there is a method in which the liquid to be treated is passed through a flat separation membrane in a direction approximately perpendicular to the entire membrane surface of the separation membrane, while there is a filtration method in which the liquid to be treated is passed through the entire membrane surface of the separation membrane in a direction parallel to the membrane surface of the separation membrane.

[0009] In filtration using a separation membrane, the effective membrane area and liquid flow affect filtration efficiency, so providing a uniform liquid flow across the entire separation membrane in a filtration device is important for performing filtration with high efficiency.

[0010] In a first aspect of the present disclosure, an object is to provide a membrane filtration vessel, a membrane evaluation vessel, a membrane filtration system, and a membrane evaluation system that can suppress the effects of corrosion on the membrane evaluation vessel and can perform membrane evaluation under high-pressure conditions using an acid- or alkali-containing aqueous solution or an organic solvent.

[0011] In a second aspect of the present disclosure, an object is to provide a filtration vessel that can suppress the influence of corrosion on the filtration vessel and enable highly efficient filtration in an acid- or alkali-containing aqueous solution or an organic solvent.

[0012] The above-mentioned object can be achieved by a membrane evaluation vessel and a membrane evaluation system for measuring separation membrane performance, the membrane evaluation vessel comprising a vessel made of polyether ether ketone (PEEK) or polyphenylene sulfide (PPS), a porous support plate and a support part to be placed in the vessel, the vessel having an inlet flow path for supplying liquid to the vessel and an outlet flow path for discharging liquid, the vessel being configured so that liquid is supplied to one side of the separation membrane and the liquid that has permeated to the other side of the separation membrane is discharged through the permeate flow path, and the membrane evaluation vessel, membrane evaluation vessel, membrane filtration system, and membrane evaluation system using the membrane evaluation vessel.

[0013] [1] The membrane evaluation container of the present disclosure is a membrane evaluation container used in a membrane evaluation system for measuring the performance of a separation membrane, and includes: a container made of polyether ether ketone or polyphenylene sulfide, in which the separation membrane is installed; a porous support plate that supports the separation membrane within the container and has a plurality of through-holes; and a support part that supports the porous support plate within the container, wherein the container includes a first flow path for supplying a solution to be treated and a second flow path for discharging the solution to be treated, and is configured so that the solution to be treated is supplied from the first flow path to one side of the separation membrane, and the permeated liquid that has permeated from the other side of the separation membrane is discharged from the second flow path.

[0014] [2] The membrane evaluation container described in [1], wherein the container includes a lid member and a main container, and the main container has a recess for collecting the permeate that has permeated the separation membrane, and the separation membrane and the porous support plate are arranged in this order from the lid member side of the recess toward the main container side, and the porous support plate is made of polyether ether ketone or polyphenylene sulfide.

[0015] [3] The membrane evaluation container according to [2], wherein the support component is integrally formed with the lid member.

[0016] [4] A membrane evaluation container described in [2] or [3], wherein a first packing material is placed in the recess of the main container, and the plurality of through holes of the porous support plate are provided in an area inside the inner diameter of the first packing material.

[0017] [5] The membrane evaluation container according to [4], wherein the first packing material is made of perfluoroelastomer.

[0018] [6] The support part is made of polyether ether ketone or polyphenylene sulfide, and includes a cut surface that forms a triangular space between the outer periphery of the first packing material and the recess when the support part is placed in the recess of the main container, the cut surface presses down on the first packing material, and the length of the cut surface along the stacking direction of the lid member and the main container is in the range of 2.0 mm to 4.0 mm. [4] A membrane evaluation container described in [5] or [5].

[0019] [7] A membrane evaluation container described in any one of [4] to [6], wherein a thin film is disposed in the recess of the main container between the first gasket material and the separation membrane.

[0020] [8] The membrane evaluation container according to any one of [2] to [7], wherein the thickness of each of the lid member and the main container along the stacking direction is 20 mm to 200 mm.

[0021] [9] A membrane evaluation container described in any one of [2] to [8], wherein a second annular gasket material is provided between the lid member and the main container, the lid member includes a groove portion for accommodating the second gasket material, and the second gasket material is made of a perfluoroelastomer.

[0022]

[10] The membrane evaluation container according to any one of [1] to [9], wherein the diameter of the through holes of the porous support plate is 0.1 mm to 1.0 mm and the porosity is in the range of 50% or less.

[0023]

[11] The first flow path and the second flow path include a flow path connecting member, and the flow path connecting member is made of polyether ether ketone or polyphenylene sulfide. A membrane evaluation container described in any one of [1] to

[10] .

[0024]

[12] A membrane evaluation system for measuring the performance of a separation membrane, comprising: a supply liquid tank for storing a solution to be treated; an automatic pressure regulator for applying a predetermined pressure to the solution to be treated in the supply liquid tank; a supply liquid pump for sending the solution to be treated from the supply liquid tank to a membrane evaluation vessel in which the separation membrane is installed; and a permeate recovery tank for recovering permeate that has passed through the separation membrane from the membrane evaluation vessel, wherein the membrane evaluation vessel is the membrane evaluation vessel described in any one of [1] to

[11] .

[0025]

[13] A membrane filtration vessel of the present disclosure is a membrane filtration vessel that separates a solution to be treated into a permeate and a concentrate, and includes: a vessel made of polyether ether ketone or polyphenylene sulfide and having a separation membrane installed therein; a porous support plate that supports the separation membrane within the vessel and has a plurality of through-holes; and a support part that supports the porous support plate within the vessel. The vessel includes a first flow path for supplying the solution to be treated and a second flow path for discharging the solution to be treated within the vessel, and is configured so that the solution to be treated is supplied from the first flow path to one side of the separation membrane, and the permeate that has permeated from the other side of the separation membrane is discharged from the second flow path.

[0026]

[14] A membrane filtration system that separates a solution to be treated into a permeate and a concentrate, comprising: a supply liquid tank in which the solution to be treated is stored; an automatic pressure regulator that applies a predetermined pressure to the solution to be treated in the supply liquid tank; a supply liquid pump that sends the solution to be treated from the supply liquid tank to a membrane filtration vessel in which the separation membrane is installed; and a permeate recovery tank that recovers the permeate that has passed through the separation membrane from the membrane filtration vessel, wherein the membrane filtration vessel is the membrane filtration vessel described in

[13] .

[0027] The present technology provides the following filtration vessel:

[15] The filtration vessel of the present disclosure is a filtration vessel that uses a separation membrane to filter a liquid to be treated to separate it into a purified liquid and a permeate liquid, the filtration vessel comprising: a main container having a circular recessed space in a plan view; a lid member fixed to the main container and closing the recessed space; and a support plate disposed between the lid member and the main container and sandwiching the separation membrane together with the lid member, the lid member including a liquid inlet hole for introducing the liquid to be treated into the separation membrane, a liquid outlet hole for withdrawing the purified liquid from the separation membrane, a circular first convex surface protruding toward the main container, and a second convex surface provided inside the first convex surface, sandwiching the separation membrane together with the support plate and protruding toward the main container, the filtration vessel defining a first imaginary line passing through a center point of the first convex surface and a second imaginary line passing through the center point and perpendicular to the first imaginary line, and further including a first imaginary line extending from the first convex surface to the support plate. When the container is divided into a first region on one side and a second region on the other side using a line as a boundary, in the first region, the liquid inlet hole is provided on the first imaginary straight line of the first convex surface outer than the second convex surface, and in the second region, the liquid outlet hole is provided on the first imaginary straight line of the first convex surface outer than the second convex surface, and in the region including the second imaginary straight line, a pair of isolation regions separating the first region and the second region are provided on the first convex surface outer than the second convex surface, so that a liquid inlet flow path is provided on the first convex surface outer than the second convex surface including the liquid inlet hole, and a liquid outlet flow path is provided on the first convex surface outer than the second convex surface including the liquid outlet hole, and the main container, the lid member, and the support plate are made of polyether ether ketone or polyphenylene sulfide.

[0028]

[16] The filtration vessel according to

[15] , wherein the support plate has a plurality of through holes for discharging the permeate separated from the liquid to be treated by the separation membrane into the recess space.

[0029]

[17] The filtration container according to

[15] or

[16] , wherein the width along the radial direction of the first convex surface outside the second convex surface narrows as it moves away from the first imaginary line.

[0030]

[18] The filtration container described in

[17] , wherein the second convex surface is an ellipse whose minor axis lies on the first imaginary line and whose major axis lies on the second imaginary line.

[0031]

[19] The filtration container described in

[18] , wherein a pair of the isolation regions is provided by designing the dimensions so that the length of the major axis of the elliptical shape is longer than the diameter of the first convex surface.

[0032]

[20] The filtration container described in any one of

[15] to

[19] , wherein the liquid introduction hole has a triangular pyramidal hole whose opening diameter gradually increases toward the opening end face of the lid member.

[0033] According to the first aspect of the present disclosure, it is possible to provide a membrane filtration vessel, a membrane evaluation vessel, a membrane filtration system, and a membrane evaluation system that can suppress the effects of corrosion on the membrane evaluation vessel and can perform membrane evaluation under high-pressure conditions using an acid- or alkali-containing aqueous solution or an organic solvent.

[0034] According to the second aspect of the present disclosure, it is possible to provide a filtration container that can suppress the influence of corrosion on the filtration container and that enables highly efficient filtration in an acid- or alkali-containing aqueous solution or organic solvent.

[0035] 1. A block diagram showing an overview of a membrane evaluation system according to a first embodiment. 2. A perspective view showing the external configuration of a membrane evaluation container according to the first embodiment. 3. An exploded perspective view of a membrane evaluation container according to the first embodiment. 4. An exploded side view of a membrane evaluation container according to the first embodiment. 5. A cross-sectional view taken along the arrows V-V in FIG. 2. 6. A plan view of a porous support plate according to the first embodiment. 7. A partially enlarged view showing the arrangement of a plurality of through-holes provided in a porous support plate according to the first embodiment. 8. A diagram showing the relationship between the hole diameter of the through-holes according to the first embodiment and the aperture ratio A and aperture ratio B. 9. A diagram showing the calculation formulas for aperture ratio A and aperture ratio B. 10. A diagram showing the evaluation results of Examples 1 to 5 and Comparative Examples 1 to 6. 11. A schematic diagram showing a case where no distortion occurs in a separation membrane and / or a porous support plate. 12. A schematic diagram showing a case where distortion occurs in a separation membrane and / or a porous support plate. 13. A plan view showing a cover member of another embodiment. 14. A cross-sectional view taken along the arrows XIV-XIV in FIG. 13. 15. A diagram showing the resin material physical properties of PEEK and PPS. 16. A first diagram showing the chemical resistance of PEEK and PPS. 20. FIG. 2 is a second diagram showing the chemical resistance of PEEK and PPS. FIG. 3 is a diagram showing the chemical resistance of PEEK and PPS. FIG. 4 is a diagram showing the chemical resistance of PEEK and PPS. FIG. 2 is a perspective view showing the external configuration of a filtration vessel of embodiment 2. FIG. 2 is an exploded perspective view of a filtration vessel of embodiment 2. FIG. 2 is an exploded side view of a filtration vessel of embodiment 2. FIG. 20 is a cross-sectional view taken along the arrow XXIII-XXIII in FIG. 20. FIG. 23 is a partially enlarged cross-sectional view of an area surrounded by XXIV in FIG. 23. FIG. 23 is a plan view of a support plate of embodiment 2. FIG. 24 is a partially enlarged view showing an arrangement of a plurality of through-holes provided in a support plate of embodiment 2. FIG. 24 is a perspective view of a lid member of embodiment 2. FIG. 25 is a plan view of a lid member of embodiment 2. FIG. 26 is a plan view of a lid member of a comparative example. FIG. 27 is a first diagram showing the radial flow velocity ratio distribution on the membrane surface of a separation membrane in embodiment 2. FIG. 28 is a first diagram showing the radial flow velocity ratio distribution on the membrane surface of a separation membrane in comparative example 7. FIG. 29 is a first diagram showing a flow trajectory pattern of a filtration vessel of embodiment 2. Fig. 2 is a second diagram showing a flow path pattern of a filtration vessel in Comparative Example 7. Fig. 3 is a cross-sectional view showing the configuration of a liquid inlet hole and a liquid outlet hole in another embodiment. Fig. 4 is a cross-sectional view showing modified examples of a liquid inlet hole and a liquid outlet hole in another embodiment. Fig. 5 is a first diagram showing a design principle of a lid member in embodiment 2. Fig. 6 is a second diagram showing a design principle of a lid member in embodiment 2.Fig. 10 is a plan view showing a second protrusion of a lid member according to another embodiment;Fig. 11 is a plan view showing a second protrusion of a lid member according to yet another embodiment;Fig. 12 is a side view showing the configuration of a lid member according to yet another embodiment;Fig. 13 is a side view showing the configuration of a lid member according to yet another embodiment;Fig. 14 is a side view showing the configuration of a lid member according to yet another embodiment.

[0036] [Embodiment 1] A membrane evaluation system according to embodiment 1 of the present disclosure and a membrane evaluation container used in this membrane evaluation system will be described below with reference to the drawings. In the embodiments described below, when reference is made to numbers, quantities, etc., the scope of the present invention is not necessarily limited to those numbers, quantities, etc., unless otherwise specified. The same reference numbers are used for identical or equivalent parts, and redundant descriptions may not be repeated. It is intended from the beginning that the configurations in the embodiments will be used in appropriate combinations. For ease of understanding, the film thicknesses and layer thicknesses shown in the drawings differ from the actual ratios.

[0037] Note that Figure 15 shows the physical properties of the resin materials polyether ether ketone (PEEK) and polyphenylene sulfide (PPS) used in the following embodiments, and Figures 16 to 19 show the chemical resistance of PEEK and PPS. In Figures 16 to 19, "A" indicates almost no effect, "B" indicates usable under certain conditions, "C" indicates that it is best not to use, and "F" indicates that it is not usable. The test results in Figures 16 to 19 are judgment results after immersion at 23°C for 24 hours.

[0038] (Membrane Evaluation System 1) A membrane evaluation system 1 according to the present embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an overview of the membrane evaluation system 1 according to the embodiment. The membrane evaluation system 1 includes a supply liquid tank 100 for storing a solution to be treated, a liquid transfer pump 200, a membrane evaluation vessel 400A, an automatic pressure regulator 300, a magnetic stirrer with a temperature regulator (not shown), and a permeate recovery tank 500 for recovering the permeate that has passed through the separation membrane from the membrane evaluation vessel 400A.

[0039] The automatic pressure regulator 300 monitors the outlet side discharge pressure of the liquid delivery pump 200 using an electrical signal, and controls the outlet side discharge pressure to an arbitrary set value by automatically adjusting the flow path valve built into the automatic pressure regulator 300.

[0040] In this embodiment, a membrane evaluation system will be described in which a separation membrane is placed inside a resin membrane evaluation container 400A, a solution to be treated is supplied to the membrane evaluation container 400A using a liquid feed pump 200, and the solution to be treated is filtered through the separation membrane. As the solution to be separated, an acid- or alkali-containing aqueous solution and a liquid containing an organic solvent can be used.

[0041] (Membrane evaluation container 400A) The configuration of the membrane evaluation container 400A will be described with reference to Fig. 2 to Fig. 5. Fig. 2 is a perspective view showing the external configuration of the membrane evaluation container 400A, Fig. 3 is an exploded perspective view of the membrane evaluation container 400A, Fig. 4 is an exploded side view of the membrane evaluation container 400A, and Fig. 5 is a cross-sectional view taken along the arrow VV in Fig. 2.

[0042] Referring to FIG. 2, a resin membrane evaluation container 400A has an overall cylindrical appearance and includes a container 400. Furthermore, the container 400 has a lid member 410 and a main container 480. The lid member 410 and the main container 480 are fastened together with bolts B1 and nuts N1 using bolt holes 412 and bolt holes 485 (see FIG. 3) provided at equal intervals on the circumferential edge. Although the bolts B1 and nuts N1 are provided in eight locations on the circumference, the number is not limited to this. Fastening the lid member 410 and the main container 480 together with the bolts B1 and nuts N1 forms a flow path inside the container 400 through which the solution to be separated flows.

[0043] The solution to be separated is filtered by arranging, within a flow path formed inside the container 400, an annular O-ring 420 (second packing material) described below, an annular support part 430, an annular O-ring 440 (first packing material), an annular thin film 450 made of an impermeable thin film, a disk-shaped separation membrane 460, and a porous support plate 470 provided with a plurality of through holes 471 (see Figure 6).

[0044] The lid member 410 and the main container body 480 that constitute the container 400 are made of a resin material such as PEEK or PPS.

[0045] The thickness L1 of the lid member 410 in the vertical direction is approximately 20 mm to 200 mm. The thickness L2 of the main container 480 in the vertical direction is approximately 20 mm to 200 mm. The diameter of the container 400 in a plan view is approximately 90 mm.

[0046] Referring to Figures 3 and 4, inside the container 400 defined by the lid member 410 and the main container 480, when the stacking direction of the lid member 410 and the main container 480 is considered to be the up-down direction, an annular O-ring 420 (second packing material), an annular support part 430, an annular O-ring 440 (first packing material), an annular thin film 450, a disk-shaped separation membrane 460, and a porous support plate 470 having a plurality of through holes 471 (see Figure 6) are contained in a stacked state in this order from the lid member 410 side to the main container 480 side.

[0047] The essential components of the membrane evaluation container 400A are the lid member 410, the main container 480, the separation membrane 460 whose performance is to be evaluated, the support part 430, and the porous support plate 470, but in order to more highly evaluate the performance of the separation membrane 460, it is preferable that the container be equipped with the O-ring 420, the O-ring 440, and the thin film 450 described above.

[0048] (Cover member 410) The cover member 410 has a cover main body 411 and first flow paths 413 that penetrate the cover main body 411 in the thickness direction at two locations, penetrating from the top surface side to the bottom surface side of the cover main body 411. A flow path connecting member TS1 is connected to the first flow path 413. A resin tube is filled inside the flow path connecting member TS1 and fixed in place with a tool.

[0049] The tube connected to the discharge side of the solution to be treated is connected to an automatic pressure regulator 300, and a circulation tube (not shown) for returning the solution to the supply liquid tank 100 is connected to the outlet side of the automatic pressure regulator 300.

[0050] An annular groove 410m for accommodating an O-ring 420 is provided on the surface of the cover member 410 facing the support part 430. The O-ring 420 is preferably made of perfluoroelastomer (FFKM) or the like.

[0051] (Main container 480) The main container 480 is provided with a recess 482 having a cylindrical inner surface for collecting the permeated liquid that has passed through the separation membrane 460. In this recess 482, the separation membrane 460 and a porous support plate 470 are arranged in this order from the lid member 410 side toward the main container 480 side. The porous support plate 470 is made of PEEK or PSS. A circular step 483 for collecting the permeated liquid is provided on the bottom surface of the recess 482 of the main container 480.

[0052] The main container 480 is provided with one second flow path 486 that communicates with the recess 482 and is used to discharge the permeated liquid. The second flow path 486 is a flow path that opens from the bottom surface of the recess 482 and from the side surface at the center in the thickness direction of the main container 480.

[0053] Furthermore, in order to collect the permeate, a permeate collection groove 483m communicating with the second flow path 486 is provided in the step portion 483. The permeate collection groove 483m may be a groove provided in an annular shape or a groove arranged in a lattice pattern, and the shape of the groove is not limited.

[0054] A flow path connecting member TS1 is connected to the second flow path 486. A resin tube is filled inside the flow path connecting member TS1 and fixed with a tool. The other end of the resin tube is connected to the permeate recovery tank 500.

[0055] It is preferable to use perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), or PEEK as the material for the resin tube connected to the flow path connecting member TS1 described above, but the material is not limited to the above as long as it has solvent resistance and pressure resistance.

[0056] The solution to be treated is supplied to one side of the separation membrane 460 (the side of the lid member 410) from the first flow path 413, and the permeated liquid that has permeated the separation membrane 460 from the other side of the separation membrane 460 (the side of the main container 480) is discharged from the second flow path 486.

[0057] (Internal Structure of Recess 482) Referring to Fig. 5, in recess 482 of main container 480, an annular O-ring 420 (second packing material), an annular support part 430, an annular O-ring 440 (first packing material), an annular thin film 450, a disk-shaped separation membrane 460, and a porous support plate 470 having a plurality of through holes 471 are arranged so as to be sandwiched by lid member 410. Note that in Fig. 5, cross-sectional views of thin film 450, separation membrane 460, and porous support plate 470 are omitted to facilitate understanding of the internal structure.

[0058] (Supporting part 430) The supporting part 430 is used to adjust the crushing ratio of the O-ring 440 installed inside the recess 482 of the main container 480. The preferable crushing ratio of the O-ring 440 is about 10% to 30%. The supporting part 430 is preferably made of PEEK or PPS. The O-ring 440 is preferably made of FFKM or the like.

[0059] When support part 430 is placed in recess 482 of main container 480 and O-ring 440 is pressed against it, the outer circumferential surface of support part 430 includes cut surface C that forms a triangular space A1 between support part 430 and recess 482. This cut surface C that contacts and presses O-ring 440 is angled at 45°, and the cut length C1 (see FIG. 4) along the stacking direction of lid member 410 and main container 480 is preferably in the range of approximately 2.0 mm to 4.0 mm.

[0060] If the cut length C1 is long, the O-ring 440 cannot be sufficiently pressed down, and the permeated liquid leaks out of the recess 482. On the other hand, if the cut length C1 is short, the elastic deformation force of the O-ring 440 increases, which may make it difficult to fix the lid member 410 to the main container 480.

[0061] (Thin Film 450) The annular impermeable thin film 450 prevents separation membrane 460 from peeling off due to contact between separation membrane 460 and O-ring 440, and is preferably made of PPS.

[0062] (Separation membrane 460) The separation membrane 460 is a membrane whose filtration performance is to be measured, and is placed on a porous support plate 470. The planar shape of the separation membrane 460 is substantially the same as that of the porous support plate 470. There are no particular restrictions on the thickness or material of the separation membrane 460, and a general separation membrane can be used. However, if the separation membrane is thicker, it is necessary to consider contact with supporting parts.

[0063] (Porous Support Plate 470) The porous support plate 470 will be described with reference to Fig. 6 to Fig. 9. Fig. 6 is a plan view of the porous support plate 470, Fig. 7 is a partially enlarged view showing the arrangement of a plurality of through holes 471 provided in the porous support plate 470, Fig. 8 is a diagram showing the relationship between the hole diameter of the through holes 471 and the aperture ratio A and aperture ratio B, and Fig. 9 shows Equation 1 which shows the aperture ratio A and Equation 2 which shows the aperture ratio B.

[0064] The porous support plate 470 is a circular plate-like member, preferably a punched plate, similar to the main container 480. The porous support plate 470 has a plurality of through holes 471 formed therein, as will be described later. The through holes 471 are preferably formed in an area inside the inner diameter of the O-ring 440.

[0065] The material of the porous support plate 470 is preferably made of resin, as it is intended to treat solutions that are resistant to acids and alkalis, and examples of such materials include PEEK, PTFE, polyethylene (PE), polypropylene (PP), and polyphenylene sulfide (PSS). Materials other than these resins can also be used as long as they are resistant to acids and alkalis. The porous support plate 470 preferably has a pore diameter of 0.1 mm to 1.0 mm and an open area ratio of 5% to 50%.

[0066] If the pore diameter is large, the separation membrane 460 will sink into the through-holes 471 of the porous support plate 470 during evaluation, leading to distortion or breakage of the separation membrane 460. If the open area ratio is small, the effective membrane area of ​​the separation membrane 460 will be small. If the open area ratio is large, the mechanical strength of the porous support plate 470 will be reduced due to the increased porosity, leading to breakage under pressure. There are no particular restrictions on the thickness of the porous support plate 470, but an increased thickness raises concerns about increased permeation resistance and retention of permeate. On the other hand, a decreased thickness reduces the pressure resistance of the porous support plate 470. Taking all of these factors into consideration, the thickness of the porous support plate 470 is preferably approximately 1 mm to 5 mm.

[0067] 9, the aperture ratio A in Equation 1 represents the total aperture area / effective area (%) (area in contact with the solution to be treated) of the through-holes 471 in the porous support plate 470, and the aperture ratio B in Equation 2 represents a theoretical calculation (%), where D represents the aperture diameter D1 and P represents the distance between the centers of the holes (pitch), as shown in FIG. 7. The total aperture area and effective area of ​​the aperture ratio A can be obtained by image analysis of the through-holes 471 in the porous support plate 470.

[0068] The through holes 471 are arranged in a staggered pattern as shown in Fig. 7, with an arrangement angle (α1) of 60 degrees. Using the formula shown in Fig. 9, when the effective area is the same and the hole diameters of the through holes 471 are 0.6 mm / pitch distance 1 mm, 0.4 mm / pitch distance 0.8 mm, 2.0 mm / pitch distance 3.5 mm, and 2.0 mm / pitch distance 7 mm, the hole area ratios A and B are calculated. It was confirmed that there is no significant difference between the hole area ratios A and B. This indicates that the value of the hole area ratio A is effective in expressing the effects of the present disclosure.

[0069] [Examples] The evaluation results of the separation membranes in each example are shown with reference to Figure 10. As with the membrane evaluation container 400A described above, the porous support plate 470, the separation membrane 460 to be evaluated, the impermeable thin film 450, the O-ring 440, and the support part 430 were set in this order from the bottom of the main container 480, and the O-ring 420 was set in the groove 410m of the lid member 410. To maintain the joined state between the lid member 410 and the main container 480, they were fastened and fixed at eight locations using bolts B1 and nuts N1.

[0070] The cut surface C of the support part 430 used for assembly was 45°, and the cut length C1 (see FIG. 4) was 3.0 mm. After assembly, piping was connected to the membrane evaluation container 400A using a resin tube, and an acetonitrile solution was pumped as the solution to be treated. The operating pressure was set to 4.5 MPa using an automatic pressure regulator, and a membrane evaluation test of the separation membrane 460 was performed. The liquid temperature of the solution to be treated was controlled at 25±1°C using a magnetic stirrer with a temperature regulator. The test time was approximately 48 hours, and the presence or absence of distortion in the separation membrane 460 and the presence or absence of distortion in the porous support plate 470 after the test was visually confirmed. Issues that arise when distortion of the separation membrane 460 and the porous support plate 470 occurs will be discussed later.

[0071] Example 1 The porous support plate 470 was made of PEEK, had a pore size of 0.1 mm, an open area ratio A of 5.0%, and a thickness of 2.0 mm. A polymer membrane with a thickness of approximately 300 μm was used as the separation membrane 460. No distortion was observed in either the porous support plate 470 or the separation membrane 460.

[0072] Example 2 The porous support plate 470 was made of PEEK, had a pore diameter of 0.4 mm, an open area ratio A of 23%, and a thickness of 2.0 mm. A polymer membrane with a thickness of approximately 300 μm was used as the separation membrane 460. No distortion was observed in either the porous support plate 470 or the separation membrane 460.

[0073] (Example 3) The porous support plate 470 was made of PEEK, had a pore diameter of 0.6 mm, an open area ratio A of 32.7%, and a thickness of 2.0 mm. A polymer membrane with a thickness of approximately 300 μm was used as the separation membrane 460. No distortion was observed in either the porous support plate 470 or the separation membrane 460.

[0074] Example 4 The porous support plate 470 was made of PPS, with a pore size of 0.6 mm, an open area ratio A of 32.7%, and a thickness of 2.0 mm. A polymer membrane with a thickness of approximately 300 μm was used as the separation membrane 460. No distortion was observed in either the porous support plate 470 or the separation membrane 460.

[0075] Example 5 The porous support plate 470 was made of PEEK, had a pore diameter of 1 mm, an opening rate A of 50%, and a thickness of 2.0 mm. A polymer membrane with a thickness of approximately 300 μm was used as the separation membrane 460. No distortion was observed in either the porous support plate 470 or the separation membrane 460.

[0076] Comparative Example 1 The porous support plate 470 was made of PEEK, had a pore diameter of 2 mm, an open area ratio A of 29.6%, and a thickness of 2.0 mm. A polymer membrane with a thickness of approximately 300 μm was used as the separation membrane 460. Distortion was confirmed in the separation membrane 460.

[0077] Comparative Example 2 The porous support plate 470 was made of PEEK, had a pore diameter of 2 mm, an open area ratio A of 7.4%, and a thickness of 2.0 mm. A polymer membrane with a thickness of approximately 300 μm was used as the separation membrane 460. Distortion was confirmed in the separation membrane 460.

[0078] Comparative Example 3 An experiment was conducted under the same conditions as in Example 1, except that porous support plate 470 was changed to a sintered plate (material: HDPE (high-density polyethylene), pore size: 0.1 mm). Distortion was confirmed in both separation membrane 460 and porous support plate 470.

[0079] Comparative Example 4 An experiment was conducted under the same conditions as in Example 1, except that porous support plate 470 was changed to a sintered plate (material: UHPE (ultra-high molecular weight polyethylene), pore size: 0.002 mm). Distortion was confirmed in both separation membrane 460 and porous support plate 470.

[0080] Comparative Example 5 An experiment was conducted under the same conditions as in Example 1, except that porous support plate 470 was changed to a sintered plate (material: PTFE, pore size: 0.01 mm). Distortion was confirmed in both separation membrane 460 and porous support plate 470.

[0081] Comparative Example 6 An experiment was conducted under the same conditions as in Example 1, except that porous support plate 470 was changed to a sintered plate (material: PEEK, pore size: 0.01 mm). Distortion was confirmed in both separation membrane 460 and porous support plate 470.

[0082] When the cut surface C of the support part 430 used for assembly was set at 45° and the cut length C1 (see FIG. 4) was set to 1.5 mm, assembly was only possible with a gap between the lid member 410 and the main container 480. When the same operating pressure as in Example 1 was applied, the solution to be treated leaked from the gap, making it impossible to perform the test.

[0083] Furthermore, when the cut surface C of the support part 430 used for assembly was at 45° and the cut length C1 (see FIG. 4) was 4.5 mm, the triangular groove (triangular space A1) formed between the main container 480 and the support part 430 became larger than the linear shape of the O-ring 440, making it impossible to crush the O-ring 440 and creating a gap between the separation membrane 460 and the porous support plate 470. When the same operating pressure as in Example 1 was applied, the solution to be treated leaked from the gap between the separation membrane 460 and the porous support plate 470, making it impossible to perform the test.

[0084] From the results of each of the above examples and comparative examples, it was confirmed that by using a container 400 made of PEEK or PPS for the membrane evaluation container 400A, it is possible to provide a membrane evaluation container and a membrane evaluation system that can suppress the effects of corrosion and perform membrane evaluation under high-pressure conditions using a solution to be treated, such as an acid- or alkali-containing aqueous solution or an organic solvent.

[0085] In particular, it was confirmed that when PEEK or PPS is used for the porous support plate 470, the diameter of the through holes 471 is 0.1 mm to 1.0 mm, and the porosity is in the range of 50% or less, the separation membrane 460 can be evaluated without causing distortion in either the separation membrane 460 or the porous support plate 470.

[0086] 11 and 12, a description will be given of the problems that arise when distortion occurs in the separation membrane 460 and the porous support plate 470. When a comparison is made between a case where no distortion occurs in the separation membrane 460 and / or the porous support plate 470 as shown in Fig. 11 and a case where distortion occurs in the separation membrane 460 and / or the porous support plate 470 as shown in Fig. 12, when evaluating the same separation membrane 460 with known performance, the pressure dependency and solute removal rate decrease.

[0087] As shown in Figure 12, when the separation membrane 460 and / or the porous support plate 470 are pushed into the permeate recovery groove 483m, the components are pulled, and wavy distortion occurs in the peripheral and internal parts of the separation membrane 460 and / or the porous support plate 470.

[0088] Specifically, the evaluation of pressure dependency is defined by the formula [permeation rate = permeability × pressure], and when there is no distortion in the separation membrane 460 and / or the porous support plate 470, the permeation rate increases as the pressure increases. On the other hand, when there is distortion in the separation membrane 460 and / or the porous support plate 470, the permeation rate decreases as the pressure increases.

[0089] In evaluating the solute removal rate, for example, when a standard reagent with Mw=1000 is used as the solute, the removal rate is 98% if there is no distortion in the separation membrane 460 and / or the porous support plate 470. On the other hand, if there is distortion in the separation membrane 460 and / or the porous support plate 470, the removal rate drops to 80%.

[0090] When strain occurs in the separation membrane 460 and / or the porous support plate 470, the pressure dependency and the solute removal rate decrease.

[0091] (Other forms of lid member 410A) In the configuration described above, the lid member 410 and the support component 430 are separate components, but as shown in Figures 13 and 14, a lid member 410A in which the support component 430 is integrally formed with the lid member 410 may also be used.

[0092] The lid member 410A has a lid main body 411A and a support portion 430A that protrudes downward from the lid main body 411A. A first flow path 413 is provided so as to penetrate the lid main body 411A and the support portion 430A. A cut surface C is provided on the outer peripheral surface of the support portion 430A.

[0093] By providing the cover member 410A in which the support component 430 is integrally formed with the cover member 410, the use of the O-ring 440 becomes unnecessary, and furthermore, the assembly process of the membrane evaluation container 400A can be simplified.

[0094] The above examples show evaluation results using an organic solvent (acetonitrile solution). It is believed that the chemical resistance of PEEK and PPS shown in Figures 16 to 19 allows evaluation results similar to those of the examples to be obtained even in acidic or alkaline solutions.

[0095] Since PTFE is a material with excellent chemical resistance, it is conceivable to use PTFE for the container 400 (lid member 410, main container body 480), but from the viewpoint of pressure resistance, it would be necessary to reinforce the container from the outside with a stainless steel container or the like, which would make the container assembly complicated. Therefore, as described above, it is preferable to make the container 400 from a resin material made of PEEK or PPS.

[0096] The membrane evaluation vessel described above is not limited to those used in evaluation systems for measuring the performance of separation membranes, and can also be used as a membrane filtration vessel when measuring the performance of separation membranes. It can also be used as a membrane that simply separates a solution to be treated into a permeate and a concentrate, or as a membrane or membrane filtration system that obtains a permeate from a solution to be treated without obtaining a concentrate.

[0097] 20 to 23, the configuration of the filter container 4000A will be described. This filter container 4000A is intended to be used mainly when purifying a liquid to be treated that contains an acid- or alkali-containing aqueous solution or an organic solvent.

[0098] Referring to FIG. 20 , a resin filter vessel 4000A has an overall cylindrical appearance. The filter vessel 4000A includes a cover member 4100 and a main vessel 4800. The cover member 4100 and the main vessel 4800 are fastened together with bolts B10 and nuts N10 using bolt holes 4120 and bolt holes 4850 (see FIG. 21 ) provided at equal intervals on the circumferential edge. Although the bolts B10 and nuts N10 are provided in eight locations on the circumference, the number is not limited to this. Fastening the cover member 4100 and the main vessel 4800 together with the bolts B10 and nuts N10 forms a flow path within the filter vessel 4000 through which the liquid to be treated flows.

[0099] The liquid to be treated is filtered by arranging an annular O-ring 4200 (second packing material) described below, an annular support part 4300, an annular O-ring 4400 (first packing material), an annular thin film 4500 made of an impermeable thin film, a circular separation membrane 4600, and a support plate 4700 provided with a plurality of through holes 4710 (see Figure 24) in a flow path formed inside the filtration vessel 4000A.

[0100] At least the cover member 4100, the main container 4800, and the support plate 4700 that constitute the filtration container 4000A are made of a resin material such as PEEK (polyether ether ketone) or PPS (polyphenylene sulfide).

[0101] The thickness L10 of the cover member 4100 in the vertical direction is approximately 20 mm to 200 mm. The thickness L20 of the main container 4800 in the vertical direction is approximately 20 mm to 200 mm. The diameter of the filtration container 4000A in plan view is approximately 130 mm.

[0102] 21 to 24, when the stacking direction of the lid member 4100 and the main body container 4800 is defined as the vertical direction, the interior of the filtration container 4000A defined by the lid member 4100 and the main body container 4800 contains, stacked in this order from the lid member 4100 side toward the main body container 4800 side, an annular O-ring 4200 (second packing material), an annular support part 4300, an annular O-ring 4400 (first packing material), an annular thin film 4500, a circular separation membrane 4600, and a support plate 4700 having a plurality of through holes 4710 (see FIG. 26).

[0103] The filtration container 4000A is composed of a cover member 4100, a main container 4800, a separation membrane 4600, a support part 4300, and a support plate 4700, but in order to further improve the separation characteristics of the separation membrane 4600, it is preferable that it is equipped with the O-ring 4200, O-ring 4400, and thin film 4500 described above.

[0104] (Lid member 4100) Lid member 4100 includes a lid main body 4110, a circular first convex surface 4100A that protrudes toward main body container 4800, and a second convex surface 4100B that is provided inside first convex surface 4100A, sandwiches separation membrane 4600 together with support plate 4700, and protrudes toward main body container 4800. The protrusion amount (length) of second convex surface 4100B relative to first convex surface 4100A is approximately 1.0 mm to 5.0 mm.

[0105] The first convex surface 4100A, which is outer than the second convex surface 4100B, is provided with a liquid inlet hole 4130a that penetrates the thickness of the lid body 4110 and the first convex surface 4100A and introduces the liquid to be treated into the separation membrane 4600, and a liquid outlet hole 4130b that extracts the purified liquid from the separation membrane 4600.

[0106] A flow path connecting member TS10 is connected to the liquid inlet hole 4130a and the liquid outlet hole 4130b. A resin tube is filled inside the flow path connecting member TS10 and fixed with a tool. Details of the shape of the second convex surface 4100B and the positions of the liquid inlet hole 4130a and the liquid outlet hole 4130b will be described later.

[0107] An annular groove 4100m for accommodating an O-ring 4200 is provided on the surface of the cover member 4100 facing the support part 4300. The O-ring 4200 is preferably made of perfluoroelastomer (FFKM) or the like.

[0108] (Main container 4800) The main container 4800 is provided with a recess 4820 having a cylindrical inner surface for collecting the permeated liquid that has passed through the separation membrane 4600. In this recess 4820, the separation membrane 4600 and a support plate 4700 are arranged in this order from the lid member 4100 side toward the main container 4800 side. The support plate 4700 is made of PEEK or PPS. A circular step 4830 is provided on the bottom surface of the recess 4820 of the main container 4800 for collecting the permeated liquid.

[0109] The main container 4800 is provided with one permeate outlet channel 4860 that communicates with the recess 4820 and discharges the permeate to the outside. The permeate outlet channel 4860 is a flow path that opens from the bottom surface of the recess 4820 and opens from the side surface at the center in the thickness direction of the main container 4800. Note that at the cross section taken along line XXIII-XXIII in Figure 20, the permeate outlet channel 4860 is in a position that cannot be shown in Figure 23 (a position shifted by 90 degrees), but for convenience of explanation, the permeate outlet channel 4860 is shown by a dashed line.

[0110] Furthermore, in order to recover the permeate, the step portion 4830 is provided with a permeate recovery groove 4830m that communicates with the permeate discharge path 4860. The permeate recovery groove 4830m may be a groove provided in an annular shape or may be a groove arranged in a lattice pattern, and the shape of the groove is not limited.

[0111] A flow path connecting member TS10 is connected to the permeate outlet channel 4860. A resin tube is filled inside the flow path connecting member TS10 and fixed with a tool. The other end of the resin tube is connected to a permeate container (not shown).

[0112] It is preferable to use perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), or PEEK as the material for the resin tube connected to the above-mentioned flow path connecting member TS10, but the material is not limited to the above as long as it has solvent resistance and pressure resistance.

[0113] 23 , the separation membrane 4600 is sandwiched between the second convex surface 4100B and the support plate 4700. For ease of illustration, the support plate 4700 is not shown in FIG. 23 . The liquid to be treated (indicated by arrow Y10 in the figure) introduced from the liquid inlet hole 4130a toward the separation membrane 4600 passes through the separation membrane 4600 along the membrane surface direction of the disc-shaped separation membrane 4600 from the liquid introduction flow path FP10 and is filtered (indicated by arrow Y20 in the figure). The separated purified liquid passes through the liquid outlet flow path FP20 and is sent from the liquid outlet hole 4130b to a purified liquid container (not shown) (indicated by arrow Y30 in the figure).

[0114] (Internal Structure of Recess 4820) In recess 4820 of main container 4800, an annular O-ring 4200 (second packing material), an annular support part 4300, an annular O-ring 4400 (first packing material), an annular thin film 4500, a circular separation membrane 4600, and a support plate 4700 provided with a plurality of through holes 4710 are arranged so as to be sandwiched by lid member 4100. In Fig. 23, cross-sectional views of thin film 4500, separation membrane 4600, and support plate 4700 are omitted to facilitate understanding of the internal structure.

[0115] (Supporting part 4300) The supporting part 4300 is used to adjust the crushing ratio of the O-ring 4400 installed inside the recess 4820 of the main container 4800. The preferable crushing ratio of the O-ring 4400 is about 10% to 30%. The supporting part 4300 is preferably made of PEEK or PPS. The O-ring 440 is preferably made of FFKM or the like.

[0116] When the support part 4300 is placed in the recess 4820 of the main container 4800 and the O-ring 4400 is pressed against it, the outer peripheral surface of the support part 4300 includes a cut surface C (see FIG. 22 ) that forms a triangular space T1 between the recess 4820 and the support part 4300. The cut surface C that contacts and presses the O-ring 4400 is angled at 45°, and the length of the cut surface C along the stacking direction of the lid member 4100 and the main container 4800 is preferably in the range of approximately 2.0 mm to 4.0 mm.

[0117] If the length of the cut surface C is long, the O-ring 4400 cannot be sufficiently pressed down, and the permeated liquid leaks out of the recess 4820. On the other hand, if the length of the cut surface C is short, the elastic deformation force of the O-ring 4400 increases, which may make it difficult to fix the lid member 4100 to the main container 4800.

[0118] (Thin Film 4500) The annular impermeable thin film 4500 prevents separation membrane 4600 from coming into contact with O-ring 4400, and is preferably made of PPS.

[0119] (Separation Membrane 4600) The separation membrane 4600 has a diameter of approximately 40 mm to 100 mm and a thickness of 0.1 mm to 2.0 mm.

[0120] 25 and 26 , the support plate 4700 will be described. From the viewpoints of pressure resistance during testing and ease of manufacture, the support plate 4700 is a circular plate-shaped member similar to the main container 4800, and is preferably a punched plate. As will be described later, the support plate 4700 is provided with a plurality of through holes 4710, and the area in which the through holes 4710 are provided should preferably be located in a region inside the inner diameter of the O-ring 4400.

[0121] The material of the support plate 4700 is preferably a resin, since it is intended to be used for treating acid- and alkali-resistant liquids, and examples of such materials include PEEK, PTFE, polyethylene (PE), polypropylene (PP), and polyphenylene sulfide (PSS). Materials other than these resins may also be used as long as they are acid- and alkali-resistant. The support plate 4700 preferably has through holes with a diameter of approximately 0.6 mm and an aperture ratio in the range of 5% to 50%.

[0122] If the pore size is smaller than the above, separation membrane 4600 is less likely to sink into through-holes 4710 of support plate 4700 during evaluation, which can prevent distortion and breakage of separation membrane 4600. If the pore size is 5% or more, the effective membrane area of ​​separation membrane 4600 can be increased. If the pore size is 50% or less, sufficient mechanical strength of support plate 4700 can be obtained, and breakage due to pressure can be prevented.

[0123] Although there are no particular restrictions on the thickness of the support plate 4700, a thicker thickness can provide the support plate 4700 with sufficient pressure resistance. A thinner thickness can improve the fluidity of the permeate passing through the support plate 4700. On the other hand, a thinner thickness can improve the fluidity of the permeate passing through the support plate 4700. Taking these factors into consideration, the thickness of the support plate 4700 is preferably approximately 1 mm to 5 mm. As shown in FIG. 26 , the through holes 4710 are preferably formed in a 60° staggered pattern with a diameter (D) of approximately 0.6 mm and a pitch (P) of approximately 1.0 mm. In the support plate 4700, it is preferable that the hole diameter be 0.1 mm to 1.0 mm and the aperture ratio be in the range of 5% to 50%.

[0124] (Details of Second Convex Surface 4100B, Liquid Inlet Hole 4130a, and Liquid Outlet Hole 4130b) The shape of the second convex surface 4100B and the positions of the liquid inlet hole 4130a and the liquid outlet hole 4130b will be described in detail with reference to FIGS. 27 and 28. FIG.

[0125] A first imaginary straight line VL10 passing through a center point P10 of the circular first convex surface 4100A and a second imaginary straight line VL20 passing through the center point P10 and perpendicular to the first imaginary line VL10 are defined. Furthermore, the first imaginary line VL10 is used as a boundary to divide the first convex surface 4100A into a first region A10 on one side (the left side in FIG. 28 ) and a second region A20 on the other side (the right side in FIG. 28 ).

[0126] The second convex surface 4100B has an elliptical shape with its minor axis positioned on the first imaginary straight line VL10 and its major axis positioned on the second imaginary straight line VL20. The elliptical shape is designed so that both sides of the minor axis are positioned inside the outer circle of the first convex surface 4100A and both ends of the major axis coincide with the outer circle of the first convex surface 4100A or both ends of the major axis extend beyond the outer circle of the first convex surface 4100A. The shape of the ellipse will be described later.

[0127] The liquid introduction hole 4130a is provided on the first imaginary straight line VL10 of the first convex surface 4100A, outside the second convex surface 4100B, in the first region A10. The liquid discharge hole 4130b is provided on the first imaginary straight line VL10 of the first convex surface 4100A, outside the second convex surface 4100B, in the second region A20. The opening diameter of the liquid introduction hole 4130a in the first convex surface 4100A is preferably approximately 1 to 10 mm. The opening diameter of the liquid discharge hole 4130b in the first convex surface 4100A is preferably approximately 1 to 10 mm.

[0128] As described above, by defining the shape of the second convex surface 4100B and arranging the liquid inlet hole 4130a and the liquid outlet hole 4130b, a pair of isolation regions K10, K20 separating the first region A10 and the second region A20 are provided on the first convex surface 4100A outside the second convex surface 4100B in the region including the second virtual straight line VL20.

[0129] Furthermore, a liquid introduction flow path FP10 is provided in the first convex surface 4100A, which is located outside the second convex surface 4100B including the liquid introduction hole 4130a, by a step between the first convex surface 4100A and the second convex surface 4100B. More specifically, the liquid introduction flow path FP10 is defined by a space surrounded by the step between the first convex surface 4100A and the second convex surface 4100B, the separation membrane 4600, and the inner surface of the support component 4300 (see FIG. 23 ).

[0130] Similarly, a liquid discharge flow path FP210 is provided on the first convex surface 4100A, which is located outside the second convex surface 4100B including the liquid discharge hole 4130b, by a step between the first convex surface 4100A and the second convex surface 4100B. More specifically, the liquid discharge flow path FP20 is defined by the space surrounded by the step between the first convex surface 4100A and the second convex surface 4100B, the separation membrane 4600, and the inner surface of the support component 4300 (see FIG. 23 ).

[0131] Furthermore, since the second convex surface 4100B has an elliptical shape, the width (W10) along the radial direction of the first convex surface 4100A outside the second convex surface 4100B becomes narrower as it moves away from the first virtual straight line VL10.

[0132] In the above-described configuration, when the separation membrane 4600 is sandwiched between the second convex surface 4100B and the support plate 4700, the liquid to be treated introduced from the liquid introduction hole 4130a toward the separation membrane 4600 passes through the liquid introduction flow path FP10, which has low flow resistance, and flows toward the pair of isolation regions K10, K20 (arrow F1 in Figure 28).

[0133] The liquid to be treated then begins to permeate the separation membrane 4600 and flows along the membrane surface toward the liquid outlet flow path FP210. The purified liquid that has passed through the separation membrane 4600 and been filtered then flows through the liquid outlet flow path FP210 in a direction from the isolation regions K10, K20 toward the liquid outlet hole 4130b (arrow F3 in FIG. 28 ), and is sent out from the liquid outlet hole 4130b to the purified liquid container 7000.

[0134] The effects of the technology of the present disclosure will be described in further detail below based on the simulation results of the flow velocity ratio distribution and flow trajectories in Example 6 and Comparative Example 7. Fig. 29 shows a plan view of the lid member in the comparative example.

[0135] In Example 6, the analysis target was a filtration vessel in which the cover member 4100 has a liquid introduction flow path FP10 and a liquid discharge flow path FP20 formed by a step between a first convex surface 4100A and a second convex surface 4100B, as shown in Fig. 28. In the configuration of the comparative example shown in Fig. 29, the analysis target was a filtration vessel in which the cover member 4100 does not have a second convex surface 4100B, and the surface of the first convex surface 4100A is located at the same height as the second convex surface 4100B in the example, and which does not have a step structure.

[0136] The simulation was performed using commercial fluid analysis software (Fluent 2024R1, manufactured by Ansys). Three-dimensional shape data for the filtration vessel was created using commercial CAD software (SpaceClaim 2024R1, manufactured by Ansys).

[0137] The simulation focused on the fluid domain inside the filter vessel, with the boundary condition of zero flow velocity at the wall.

[0138] In the simulation, the fluid flowing through the filtration vessel was assumed to be water (25°C). A boundary condition was set in which water at the same temperature as the ambient temperature steadily flows into the filtration vessel from the liquid inlet hole 413a at a flow rate of 5 × 10 m / s under an ambient temperature of 25°C, and a steady-state solution was obtained by simulating the flow of the liquid to be treated within the filtration vessel.

[0139] 30 and 31 show the results of a simulation of the radial flow rate ratio distribution of the liquid to be treated on the membrane surface of the separation membrane 4600. Using the center point P10 of the first convex surface 4100A as the reference point, positions on the second virtual straight line VL20 away from the center point P10 are indicated as 10 mm, 20 mm, 30 mm, and 40 mm, and plotted on the horizontal axis. The flow rate of the liquid to be treated at the center point P10 divided by the flow rate at each position away from the center point P10 is plotted as the flow rate ratio [-] on the vertical axis. The value of the flow rate ratio at the center point P10 is "1."

[0140] Referring to Figure 30, in the case of the filtration vessel 4000A using the cover member 4100 having the second convex surface 4100B of this embodiment, the flow rate ratio is maintained at "1" even at a position 25 mm away from the center point P10, and the flow rate ratio is maintained at "0.81" even at a position 38 mm away (a position almost close to the periphery of the separation membrane 4600).

[0141] 31 shows a schematic diagram of the flow velocity ratio of the liquid to be treated at the membrane surface of the separation membrane 4600 in the case of the filtration vessel of Comparative Example 7, in which the second convex surface 4100B is not provided and the separation membrane 460 is sandwiched between the first convex surface 4100A and the support plate 4700. The flow velocity ratio of the liquid to be treated decreases with increasing distance from the center point P10, and at a position 38 mm away from the center point P10, the flow velocity ratio has decreased to "0.5."

[0142] Furthermore, FIGS. 32 and 33 show the progress of the flow of the liquid to be treated obtained from the simulation using flow trajectories.

[0143] 32 shows the flow trajectories when the filtration vessel 4000A of the present embodiment is used, and it can be seen that, with the passage of time, the flow trajectories extend almost uniformly over the entire membrane surface of the separation membrane 4600. The flow rate is 3 cc / min.

[0144] On the other hand, Figure 33 shows the flow path when the comparative example filtration vessel was used, and it can be seen that with the passage of time, there is a large difference in the position where the flow path reaches between the central region and the edge region. The flow rate is 3 cc / min.

[0145] In this way, by providing the second convex surface 4100B, the liquid introduction flow path FP10 including the liquid introduction hole 4130a, and the liquid discharge flow path FP20 including the liquid discharge hole 4130b, it is possible to suppress a decrease in the flow rate of the liquid to be treated across the entire surface of the separation membrane 4600. Since the liquid to be treated passes evenly across the entire surface of the separation membrane 4600, the filtration efficiency of the liquid to be treated can be improved. As a result, the filtration vessel 4000A of the present embodiment achieves uniform flow of the liquid to be treated at low flow rates and enables highly efficient filtration of liquid to be treated containing an acid- or alkali-containing aqueous solution or an organic solvent.

[0146] (Other Configurations of Liquid Inlet Hole 4130a and Liquid Outlet Hole 4130b) Here, other configurations of the liquid inlet hole 4130a and liquid outlet hole 4130b will be described. The above-described liquid inlet hole 4130a and liquid outlet hole 4130b are cylindrical holes that extend uniformly toward the open end face of the cover member 4100. On the other hand, the liquid inlet hole 4130a shown in FIG. 34 has a triangular pyramid-shaped conical hole 4130t (with a tapered inner wall surface) whose opening diameter gradually increases toward the open end face of the cover member 4100. The liquid outlet hole 4130b has the same configuration as the liquid inlet hole 4130a.

[0147] By having the liquid introduction hole 4130a have the structure shown in Figure 34, it is possible to prevent the liquid flow from stagnating near the liquid introduction hole 4130a (preventing the generation of vortices), which has the advantage of making it easier to remove air bubbles that may have formed during stagnation (the same applies to the liquid discharge hole 4130b).

[0148] Note that Figure 35 shows a modified example of the liquid introduction hole 4130a shown in Figure 34. In the modified example of the liquid introduction hole 4130a shown in Figure 35, a cylindrical hole 4130p is provided continuous with a conical hole 4130t. This modified example of the liquid introduction hole 4130a can also obtain the effects shown in Figures 35 and 36. A similar modified example can also be applied to the liquid discharge hole 4130b.

[0149] (Design Guidelines) Here, design guidelines for designing the first convex surface 4100A, the second convex surface 4100B, the liquid inlet hole 4130a, and the liquid outlet hole 4130b will be described with reference to Figures 36 and 37. Figure 36 illustrates the first convex surface 4100A and the second convex surface 4100B in plan view.

[0150] Referring to FIG. 37, as described above, the circular first convex surface 4100A is divided into the first imaginary straight line VL10 and the second imaginary straight line VL20 passing through the center point P10 thereof, and into the first region A10 and the second region A20.

[0151] The second convex surface 4100B has an elliptical shape with its minor axis positioned on the first imaginary straight line VL10 and its major axis positioned on the second imaginary straight line VL20. The elliptical shape is designed so that both sides of the minor axis are positioned inside the outer circle of the first convex surface 4100A and both ends of the major axis either coincide with the outer circle of the first convex surface 4100A or extend beyond the outer circle of the first convex surface 4100A (extending regions HM10, HM20).

[0152] The liquid inlet hole 4130a is provided in the first region A10 on the first imaginary straight line VL10 of the first convex surface 4100A, outside the second convex surface 4100B. The liquid outlet hole 4130b is provided in the second region A20 on the first imaginary straight line VL10 of the first convex surface 4100A, outside the second convex surface 4100B.

[0153] In the region including the second virtual straight line VL20, a pair of isolation regions K10, K20 separating the first region A10 and the second region A20 are provided on the first convex surface 4100A outside the second convex surface 4100B.

[0154] A liquid introduction flow path FP10 is provided on the first convex surface 4100A, which is located outside the second convex surface 4100B including the liquid introduction hole 4130a, due to the difference in level between the first convex surface 4100A and the second convex surface 4100B.Similarly, a liquid discharge flow path FP210 is provided on the first convex surface 4100A, which is located outside the second convex surface 4100B including the liquid discharge hole 4130b, due to the difference in level between the first convex surface 4100A and the second convex surface 4100B.

[0155] Since the second convex surface 4100B has an elliptical shape, the width (W10) along the radial direction of the first convex surface 4100A outside the second convex surface 4100B becomes narrower as it moves away from the first virtual straight line VL10.

[0156] As an example of specific dimensions, if the diameter of the circular first convex surface 4100A is approximately 75 mm, the length of the minor axis (Db) of the second convex surface 4100B is preferably approximately 60 mm to 67 mm, and for example, 67 mm can be selected. The length of the major axis (Da) is preferably approximately 75 mm to 85 mm, and for example, 76 mm can be selected. The lengths of the protruding regions HM10 and HM20 on the second virtual straight line VL20 are both approximately 0.5 mm ((76-75) / 2 mm). The thickness (height h1 (see FIG. 22)) of the step between the first convex surface 4100A and the second convex surface 4100B is 2 mm.

[0157] 36 and 37, the effective area and step area of ​​second convex surface 4100B will be described. The effective area is the inside of second convex surface 4100B. The key points are: (a) effective diameter D≧flow path length Dflow; (b) effective diameter D>minor axis Db; (c) major axis Da≧effective diameter D; (d) oblateness of ellipse<20%; and (e) step thickness is the minimum distance between separation membrane 460 and the step.

[0158] The flow path length Dflow is not the center-to-center distance between the liquid inlet hole 4130a and the liquid outlet hole 4130b, but the shortest distance from the opening edge. The oblateness of the ellipse can be calculated by (Da - Db) / Da. The occupancy rate of the step portion can be calculated by dividing the step portion area by the effective area. The step between the first convex surface 4100A and the second convex surface 4100B, i.e., the area of ​​the liquid inlet flow path FP10 and the liquid outlet flow path FP20, can be calculated by [area of ​​ellipse - excess area above the effective diameter = [(Da / 2) x (Db / 2) x PI (Pi)] - [((Da - D) / 2) x (Db / 2) x PI (Pi)].

[0159] (Another Embodiment) Another embodiment of the second convex surface 4100B will be described with reference to Figs.

[0160] In order to provide the pair of isolation regions K10, K20, the above-described second convex surface 4100B is designed in such a way that the apex of the second convex surface 4100B on the long axis side, which is located on the second virtual straight line VL20, extends beyond the first convex surface 4100A. However, as shown in Figure 38, even if the apex of the second convex surface 4100B on the long axis side does not extend beyond the first convex surface 4100A, a weir member 4100C that blocks the liquid introduction flow path FP10 and the liquid discharge flow path FP20 may be disposed in the region corresponding to the pair of isolation regions K10, K20.

[0161] Furthermore, as another embodiment, as shown in Figure 39, instead of using an ellipse for the second convex surface 4100B, the second convex surface 4100B may be circular with a smaller outer diameter than the first convex surface 4100A, and a dam member 4100C that blocks the liquid introduction flow path FP10 and the liquid discharge flow path FP20 may be placed in the area corresponding to the pair of isolation areas K10, K20.

[0162] (Filtration vessel 4000B) Furthermore, as a filtration vessel of another embodiment, a filtration vessel 4000B will be described. Figure 40 is a cross-sectional view corresponding to the view seen from the arrows XXIII-XXIII in Figure 20. Note that at the cross-sectional position of XXIII-XXIII line shown in Figure 20, the permeate discharge channel 4860 is in a position that cannot be shown in Figure 40 (a position shifted by 90 degrees), but for convenience of explanation, the permeate discharge channel 4860 is shown by a dashed line.

[0163] In the filtration vessel 4000A described in Figure 23, the cover member 4100 was provided with a liquid inlet hole 413a0 and a liquid outlet hole 4130b, and the liquid inlet hole 4130a communicated with the liquid introduction flow path FP10, and the liquid outlet hole 4130b communicated with the liquid outlet flow path FP20.

[0164] On the other hand, in the filtration container 4000B, a support part 4300 is integrally formed on the cover member 4100, and a liquid inlet hole 4130a is provided from the side of the main container 4800 toward the liquid introduction flow path FP10, and a liquid outlet hole 4130b is provided from the liquid outlet flow path FP20 toward the side of the main container 4800.

[0165] Specifically, the liquid introduction hole 4130a includes a first liquid introduction region 4130a1 and a second liquid introduction region 4130a2 provided in the main container body 4800. The liquid discharge hole 4130b includes a first liquid discharge region 4130b1 and a second liquid discharge region 4130b2.

[0166] In this way, the filtration vessel 4000B is configured so that the liquid to be treated is introduced from the side and the purified liquid is taken out from the side, but it can achieve the same effects as the above-mentioned filtration vessel 4000A. Note that the shapes of the liquid inlet hole 4130a and the liquid outlet hole 4130b may be the triangular pyramidal hole shapes described in Figure 34 or 35.

[0167] (Filtration vessel 4000C, filtration vessel 4000D) Furthermore, as filtration vessels of other embodiments, filtration vessels 4000C and 4000D will be described. Figures 41 and 42 are cross-sectional views corresponding to the view seen from the arrows XXIII-XXIII in Figure 20. Note that at the cross-sectional position of line XXIII-XXIII shown in Figure 20, the permeate discharge channel 4860 is in a position that cannot be shown in Figures 41 and 42 (a position shifted by 90 degrees), but for convenience of explanation, the permeate discharge channel 4860 is shown by a dashed line.

[0168] The basic configuration of the filtration vessel 4000C and the filtration vessel 4000D is the same as that of the filtration vessel 4000A shown in Fig. 23. The difference is the arrangement of the liquid introduction hole 4130a and the liquid discharge hole 4130b.

[0169] 41, the liquid inlet hole 4130a is provided so as to be inclined with respect to the second convex surface 4100B, and the liquid outlet hole 4130b is perpendicular to the second convex surface 4100B. Therefore, the liquid inlet hole 4130a and the liquid outlet hole 4130b are arranged in asymmetric positions.

[0170] In a filtration vessel 4000D shown in FIG. 42, a liquid inlet hole 4130a and a liquid outlet hole 4130b are provided so as to be inclined with respect to a second convex surface 4100B, and the liquid inlet hole 4130a and the liquid outlet hole 4130b are arranged in symmetrical positions.

[0171] The filter vessels 4000C and 4000D in which the liquid inlet holes 4130a and the liquid outlet holes 4130b are arranged in this manner can also provide the same effects as those of the filter vessel 4000A described above.

[0172] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0173] DESCRIPTION OF SYMBOLS 1 Membrane evaluation system, 100 Supply liquid tank, 200 Liquid transfer pump, 300 Automatic pressure regulator, 400A Membrane evaluation container, 400 Container, 410, 410A Lid member, 410m Groove portion, 411, 411A Lid body, 412, 485 Bolt hole, 413 First flow path, 486 Second flow path, 420, 440 O-ring, 430 Support part, 430A Support part, 450 Thin film, 460 Separation membrane, 470 Porous support plate, 471 Through hole, 480 Main body container, 482 Recess, 483 Step portion, 483m Permeate collection groove, 500 Permeate collection tank, B1 Bolt, N1 Nut, TS1 Flow path connecting member, 4000A, 4000B, 4000C, 4000D Filtration vessel, 4100 lid member, 4100A first convex surface, 4100B second convex surface, 4100C weir member, 4100m groove portion, 4110 lid main body, 4120, 4850 bolt hole, 4130a liquid introduction hole, 4130p cylindrical hole, 4130t conical hole, 4130a1 first liquid introduction region, 4130a2 second liquid introduction region, 4130b liquid outlet hole, 4130b1 first liquid outlet region, 4130b2 second liquid outlet region, 4200, 4400 ring, 4300 support part, 4500 thin film, 4600 separation membrane, 4700 support plate, 4710 through hole, 4800 main vessel, 4820 recess, 4830 Step portion, 4830m permeate recovery groove, 4860 permeate discharge channel, A10 first region, A20 second region, B10 bolt, C cut surface, D diameter of through hole, Da length of major axis, Db length of minor axis, FP10 liquid introduction flow path, FP20 liquid discharge flow path, HM10, HM20 protrusion region, K10, K20 isolation region, L10 thickness of cover member, h10 thickness of step between first convex surface 4100A and second convex surface 4100B, N10 nut, P pitch of through hole, P10 center point, T10 space, TS10 flow path connecting member, VL10 first virtual straight line, VL20 second virtual straight line, W10 width, Y10 to Y30 arrows.

Claims

1. A membrane evaluation vessel used in a membrane evaluation system for measuring the performance of a separation membrane, comprising: a vessel made of polyether ether ketone or polyphenylene sulfide and having the separation membrane installed therein; a porous support plate that supports the separation membrane within the vessel and has a plurality of through-holes; and a support part that supports the porous support plate within the vessel, wherein the vessel includes a first flow path for supplying a solution to be treated into the vessel and a second flow path for discharging the solution to be treated, and the vessel is configured so that the solution to be treated is supplied from the first flow path to one side of the separation membrane, and a permeated liquid that has permeated from the other side of the separation membrane is discharged from the second flow path.

2. A membrane evaluation container as described in claim 1, wherein the container includes a lid member and a main container, the main container has a recess for collecting the permeate that has permeated the separation membrane, the separation membrane and the porous support plate are arranged in this order from the lid member side of the recess toward the main container side, and the porous support plate is made of polyether ether ketone or polyphenylene sulfide.

3. The membrane evaluation container according to claim 2, wherein the support component is integrally provided with the lid member.

4. A membrane evaluation container as described in claim 2, wherein a first packing material is placed in the recess of the main container, and the plurality of through holes of the porous support plate are provided in an area inside the inner diameter of the first packing material.

5. The membrane evaluation container according to claim 4, wherein the first packing material is made of perfluoroelastomer.

6. The membrane evaluation container according to claim 4, wherein the support part is made of polyether ether ketone or polyphenylene sulfide, includes a cut surface that forms a triangular space between the outer periphery of the first packing material and the recess when the support part is placed in the recess of the main container, the cut surface presses down on the first packing material, and the length of the cut surface along the stacking direction of the lid member and the main container is in the range of 2.0 mm to 4.0 mm.

7. The membrane evaluation container according to claim 4, wherein a thin film is disposed in the recess of the main container between the first packing material and the separation membrane.

8. The membrane evaluation container according to claim 2, wherein the thickness of each of the cover member and the main container along the stacking direction is 20 mm to 200 mm.

9. The membrane evaluation container according to claim 2, wherein a second annular packing material is provided between the lid member and the main container, the lid member includes a groove portion for accommodating the second packing material, and the second packing material is made of perfluoroelastomer.

10. The membrane evaluation container according to claim 1, wherein the through holes of the porous support plate have a diameter of 0.1 mm to 1.0 mm and an opening rate of 50% or less.

11. The membrane evaluation container according to claim 1, wherein the first flow path and the second flow path include a flow path connecting member, and the flow path connecting member is made of polyether ether ketone or polyphenylene sulfide.

12. A membrane evaluation system for measuring the performance of a separation membrane, comprising: a supply liquid tank for storing a solution to be treated; an automatic pressure regulator for applying a predetermined pressure to the solution to be treated in the supply liquid tank; a supply liquid pump for sending the solution to be treated from the supply liquid tank to a membrane evaluation vessel in which the separation membrane is installed; and a permeate recovery tank for recovering permeate that has passed through the separation membrane from the membrane evaluation vessel, wherein the membrane evaluation vessel is a membrane evaluation vessel described in any one of claims 1 to 11.

13. A membrane filtration vessel that separates a solution to be treated into a permeate and a concentrate, comprising: a vessel made of polyether ether ketone or polyphenylene sulfide and having a separation membrane installed therein; a porous support plate that supports the separation membrane within the vessel and has a plurality of through holes; and a support part that supports the porous support plate within the vessel, wherein the vessel includes a first flow path for supplying the solution to be treated and a second flow path for discharging the solution to be treated, and is configured so that the solution to be treated is supplied from the first flow path to one side of the separation membrane, and the permeate that has permeated from the other side of the separation membrane is discharged from the second flow path.

14. A membrane filtration system that separates a solution to be treated into a permeate and a concentrate, comprising: a supply liquid tank in which the solution to be treated is stored; an automatic pressure regulator that applies a predetermined pressure to the solution to be treated in the supply liquid tank; a supply liquid pump that sends the solution to be treated from the supply liquid tank to a membrane filtration vessel in which the separation membrane is installed; and a permeate recovery tank that recovers the permeate that has passed through the separation membrane from the membrane filtration vessel, wherein the membrane filtration vessel is the membrane filtration vessel described in claim 13.

15. A filtration vessel that uses a separation membrane to filter a liquid to be treated and separate it into a purified liquid and a permeate liquid, comprising: a main vessel having a circular recessed space in a plan view; a lid member fixed to the main vessel and closing the recessed space; and a support plate disposed between the lid member and the main vessel and sandwiching the separation membrane together with the lid member, wherein the lid member includes: a liquid inlet hole for introducing the liquid to be treated into the separation membrane, and a liquid outlet hole for removing the purified liquid from the separation membrane; a circular first convex surface that protrudes toward the main vessel; and a second convex surface provided inside the first convex surface, sandwiching the separation membrane together with the support plate and protruding toward the main vessel, wherein a first imaginary line passing through the center point of the first convex surface and a second imaginary line passing through the center point and perpendicular to the first imaginary line are defined; and further, when the vessel is divided into a first region on one side and a second region on the other side by the first imaginary line, a filtering vessel in which, in the first region, the liquid inlet hole is provided on the first imaginary straight line of the first convex surface outer than the second convex surface; in the second region, the liquid outlet hole is provided on the first imaginary straight line of the first convex surface outer than the second convex surface; in a region including the second imaginary straight line, the first convex surface outer than the second convex surface is provided with a pair of isolation regions separating the first region and the second region, so that a liquid inlet flow path is provided in the first convex surface outer than the second convex surface including the liquid inlet hole, and a liquid outlet flow path is provided in the first convex surface outer than the second convex surface including the liquid outlet hole; and the main container, the lid member, and the support plate are made of polyether ether ketone or polyphenylene sulfide.

16. The filtration vessel according to claim 15, wherein the support plate is provided with a plurality of through holes for discharging the permeated liquid separated from the liquid to be treated by the separation membrane into the recess space.

17. The filtration vessel according to claim 15, wherein the width along the radial direction of the first convex surface outside the second convex surface narrows as it moves away from the first imaginary straight line.

18. The filtration vessel according to claim 17, wherein the second convex surface has an elliptical shape with its minor axis positioned on the first imaginary line and its major axis positioned on the second imaginary line.

19. The filtering container according to claim 18, wherein a pair of the separating regions are provided by designing the dimensions such that the length of the major axis of the elliptical shape is longer than the diameter of the first convex surface.

20. The filtration vessel according to claim 15, wherein the liquid introduction hole has a triangular pyramidal hole whose opening diameter gradually increases toward the open end face of the lid member.

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