JP2015009182A - Spiral type separation membrane element and spiral type separation membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spiral type separation membrane element and a spiral type separation membrane module that can efficiently suppress a decrease in performance of a membrane element due to the generation of concentration polarization or the increase of pressure loss on the surface of the separation membrane resultant from the disturbance of a raw liquid flow during raw liquid supply.SOLUTION: This invention is a spiral type separation membrane element comprising a separation membrane of three-way sealed bag shape that separates a raw liquid, a permeation liquid channel material housed in this separation membrane, a liquid collecting tube with which the opening of the separation membrane is communicated to collect a permeation liquid in the separation membrane, and a raw liquid channel material stacked between separation membranes wound around this liquid collecting tube, where the raw liquid channel material has first constituent yarn and a plurality of strands of second constituent yarn crossing the first constituent yarn, which are integrated at crossing parts with the average minimum diameter of a linear part positioned between the crossing parts set smaller than the average maximum thickness of the crossing parts, and with the deviation amount in the thickness direction of the crossing parts of the shaft core at the linear part of the first constituent yarn with respect to the center of the thickness direction set not more than a half of the difference between the average maximum thickness and the average minimum diameter.

Description

  The present invention relates to a spiral separation membrane element and a spiral separation membrane module.

  The spiral separation membrane module is a membrane element housed in a pressure vessel. Known membrane elements include a stock solution channel material, a bag-shaped separation membrane, and a permeate channel material housed in the separation membrane wound around a collection tube.

  The stock solution channel material secures a channel for the stock solution between the separation membranes. As such a stock solution channel material, a resin net is mainly used. This net is intended to suppress inconveniences caused by disturbances in the flow of the stock solution when the stock solution is supplied to the membrane element, for example, the occurrence of concentration polarization on the surface of the separation membrane, the decrease in performance of the membrane element due to an increase in pressure loss, etc. Various improvements have been made (Japanese Patent Laid-Open Nos. 2000-437 and 2007-29808).

  As the net, one configured as a mesh spacer 8 as shown in FIG. 8 is used. The mesh spacer 8 is obtained by intersecting warp yarns 80 and weft yarns 81. The mesh spacer 8 is formed by, for example, extruding warp yarns 80 and weft yarns 81 by extrusion molding and fusing them at an intersection 82 between the warp yarns 80 and the weft yarns 81.

JP 2000-437 A JP 2007-29808 A

  However, in the spiral type separation membrane module using the conventional mesh spacer 8, the mesh spacer 8 is located between the separation membranes 90 and 91 as shown in FIG. 9, but the warp yarn 80 and the weft yarn 81 are separated over the entire length. The films 90 and 91 are in close contact with each other. Therefore, the contact area between the warp yarn 80 and the weft yarn 81 and the separation membranes 90 and 91 is large, and the disturbance of the stock solution flow during the stock solution supply cannot be sufficiently suppressed. As a result, the performance degradation of the membrane element due to the occurrence of concentration polarization on the surface of the separation membrane due to the disturbance of the stock solution flow and the increase in pressure loss cannot be sufficiently suppressed, and there is still room for improvement.

  The present invention has been made based on the circumstances as described above, and is caused by inconveniences caused by disturbance of the flow of the stock solution when the stock solution is supplied, for example, generation of concentration polarization on the separation membrane surface, increase in pressure loss, etc. It is an object of the present invention to provide a spiral separation membrane element and a spiral separation membrane module that can effectively suppress the performance degradation of the membrane element.

  In order to solve the above-mentioned problems, the present invention provides a three-side sealed bag-like separation membrane for separating a stock solution, a permeate flow path material accommodated in the separation membrane, and an opening of the separation membrane. And a collecting tube for collecting the permeate in the separation membrane, and one or a plurality of undiluted solution flow channel members stacked between one or a plurality of separation membranes wound around the collecting tube. A spiral type separation membrane element, wherein the stock solution channel material has a plurality of first constituent yarns and a plurality of second constituent yarns intersecting with the first constituent yarns, and these are integrated at a plurality of intersecting portions. The average minimum diameter of the linear portions located between the intersecting portions in the first constituent yarn is smaller than the average maximum thickness of the intersecting portions, and the axis of the linear portion of the first constituent yarn The amount of deviation in the thickness direction with respect to the center in the thickness direction of the intersecting portion of The average of the average maximum thickness and the linear portion of the serial intersection is less than half of the difference between the minimum diameter.

  Yet another aspect of the present invention made to solve the above problems is a spiral separation membrane module including the spiral separation membrane element.

  According to the present invention, it is possible to suppress the concentration polarization on the surface of the separation membrane and reduce the pressure loss by suppressing the disturbance of the stock solution flow when the stock solution is supplied. Therefore, in the spiral separation membrane element and the spiral separation membrane module provided by the present invention, the performance degradation of the membrane element is effectively suppressed.

It is a typical sectional view of the spiral type separation membrane module concerning one embodiment of the present invention. FIG. 2 is a schematic perspective view showing the membrane element of the spiral separation membrane module of FIG. It is typical sectional drawing in the state which expand | deployed the membrane element of FIG. It is a typical perspective view which shows the separation membrane of the membrane element of FIG. It is typical sectional drawing which shows the membrane element principal part of FIG. FIG. 3 is a schematic plan view showing a part of a raw solution channel material (mesh spacer) of the membrane element of FIG. 2. It is typical sectional drawing which follows the X1-X1 line | wire of FIG. It is a schematic plan view which shows a part of the stock solution flow path material (mesh spacer) of the conventional membrane element. It is typical sectional drawing which shows the principal part of the conventional membrane element.

[Description of Embodiment of the Present Invention]
In order to solve the above-mentioned problems, the present invention provides a three-side sealed bag-like separation membrane for separating a stock solution, a permeate flow path material accommodated in the separation membrane, and an opening of the separation membrane. And a collecting tube for collecting the permeate in the separation membrane, and one or a plurality of undiluted solution flow channel members stacked between one or a plurality of separation membranes wound around the collecting tube. A spiral separation membrane element, wherein the stock solution channel material has a plurality of first constituent yarns and a plurality of second constituent yarns intersecting with the first constituent yarns, and these are integrated at the intersecting portion. The average minimum diameter of the linear portions located between the intersecting portions in the first constituent yarn is smaller than the average maximum thickness of the intersecting portions, and the axis of the linear portion of the first constituent yarn is the above The amount of deviation in the thickness direction with respect to the center in the thickness direction of the intersection is The average of the average maximum thickness and the linear portion of the part is less than half of the difference between the minimum diameter.

  According to the spiral type separation membrane element, the first constituent yarn and the second constituent yarn of the undiluted liquid flow path material are integrated at the intersection, and the average minimum diameter of the linear portion of the first constituent yarn between the intersections is The deviation amount with respect to the center of the intersection portion of the axial portion of the linear portion of the first constituent yarn in the thickness direction is smaller than the average maximum thickness of the intersection portion, and the average maximum thickness of the intersection portion and the average minimum diameter of the linear portion are Less than half of the difference. Therefore, the stock solution channel material can be configured to contact the separation membrane at the intersecting portion, and the linear portion of the first constituent yarn does not contact the separation membrane. Therefore, by reducing the contact area between the linear portion of the first constituent yarn and the separation membrane, concentration polarization on the surface of the separation membrane due to disturbance of the stock solution flow during stock solution supply can be suppressed, and pressure loss can be reduced. . Thereby, in the said spiral type separation membrane element, the performance fall of a membrane element can be suppressed effectively.

  Here, the “thickness direction” refers to the overlapping direction of the first constituent yarn and the second constituent yarn. The “average maximum thickness of intersection points” is an average value of the maximum dimensions in the thickness direction at a plurality of arbitrarily selected intersection points, and is an average value of 10 points. The “average minimum diameter of the linear portion” is a value obtained by measuring the minimum diameter in the thickness direction of a portion located between two intersection portions adjacent to each other in the axial direction of each constituent yarn at a plurality of arbitrarily selected portions. The average value of 10 points. The “first constituent yarn” and the “second constituent yarn” are “first constituent yarn” that has a smaller average minimum diameter of the linear portions of these constituent yarns, and “second constituent yarn” that has a larger average minimum diameter. Is defined as When the average minimum diameters of the two constituent yarns are the same, the “first constituent yarn” and the “second constituent yarn” are arbitrarily defined.

  The first component yarn and the second component yarn may be united at the intersection. Thus, the intensity | strength of an intersection part can be raised because the 1st constituent yarn and the 2nd constituent yarn are united.

  Here, “fusion” means a state where there is no clear interface that can distinguish the first constituent yarn and the second constituent yarn as a result of the first constituent yarn and the second constituent yarn being melted and integrated. .

  The average minimum diameter of the linear portion is preferably 10% to 70% of the average maximum thickness of the intersecting portion. Thus, by setting the average minimum diameter of the linear portion within the above range with respect to the average maximum thickness of the intersecting portion, the gap between the linear portion and the separation membrane is further increased while ensuring the strength of the linear portion. Since it can be appropriately secured, it is possible to suppress disturbance of the stock solution flow when the stock solution is supplied. Therefore, in the spiral type separation membrane element, concentration polarization on the surface of the separation membrane is suppressed, pressure loss is reduced, and performance degradation of the membrane element can be more effectively suppressed.

  The average minimum diameter of the linear portion is preferably from 0.1 mm to 0.4 mm, and the average maximum thickness of the intersecting portion is preferably from 0.2 mm to 1.2 mm. Thus, by setting the average minimum diameter of the linear portion and the average maximum thickness of the intersecting portion in the above range, the gap between the linear portion and the separation membrane is more appropriately secured while ensuring the strength of the linear portion. Since it can be secured, it is possible to suppress disturbance of the stock solution flow when the stock solution is supplied. Therefore, in the spiral type separation membrane element, concentration polarization on the surface of the separation membrane is suppressed, pressure loss is reduced, and performance degradation of the membrane element can be more effectively suppressed.

  The linear portion of the first constituent yarn may be extended in the axial direction of the first constituent yarn. By extending the linear portion of the first constituent yarn in this way, the thickness of the linear portion can be reduced, and the axis of the linear portion of the first constituent yarn is centered in the thickness direction of the intersecting portion. Can be approached. Therefore, since the said linear part can be spaced apart from a separation membrane, disorder of the stock solution flow at the time of stock solution supply can be suppressed. As a result, in the spiral type separation membrane element, concentration polarization on the surface of the separation membrane is suppressed, pressure loss is reduced, and performance degradation of the membrane element can be more effectively suppressed.

  The average minimum diameter of the linear portions located between the intersecting portions in the second constituent yarn may be smaller than the average maximum thickness of the intersecting portions. Thus, by reducing the average minimum diameter of the linear portion of the second constituent yarn to be smaller than the average maximum thickness of the intersecting portion, the possibility that the linear portion of the second constituent yarn contacts the separation membrane is reduced. It is possible to further reduce the contact area between the linear portion of the second constituent yarn and the separation membrane. Therefore, concentration polarization on the surface of the separation membrane due to disturbance of the stock solution flow during stock solution supply can be suppressed, and pressure loss can be reduced. Thereby, in the spiral separation membrane element, it is possible to more effectively suppress the performance degradation of the membrane element.

  The separation membrane may be a nonwoven fabric. Thus, when the separation membrane is a non-woven fabric, the spiral separation membrane element can be applied to oil / water separation. Therefore, concentration polarization on the surface of the separation membrane during oil / water separation is suppressed, pressure loss is reduced, and performance degradation of the membrane element can be more effectively suppressed.

  The average center-to-center distance between two intersecting portions adjacent in the axial direction of the first constituent yarn or the second constituent yarn among the plurality of intersecting portions is preferably 2 mm or more and 6 mm or less. Thus, by setting the average center distance within the above range, the area occupied by the mesh spacers between the separation membranes can be appropriately reduced, so that disturbance of the stock solution flow during stock solution supply can be suppressed while reducing pressure loss. Therefore, in the spiral type separation membrane element, concentration polarization on the surface of the separation membrane is suppressed, pressure loss is reduced, and performance degradation of the membrane element can be more effectively suppressed.

  Here, the “average center-to-center distance of intersection” is an average value of the center-to-center distances of 10 points arbitrarily selected. The “center” in the “center-to-center distance” is an intersection of the axis of the first constituent yarn and the axis of the second constituent yarn in the thickness direction view.

  As the first component yarn and the second component yarn, those having polypropylene, polyethylene or crosslinked polyethylene as a main component are preferable. Since the constituent yarns mainly composed of such resin are available at a relatively low cost and have a relatively low melting point and can be easily processed, it is possible to suppress the manufacturing cost of the raw liquid flow path material.

  Another aspect of the present invention made to solve the above problems is a spiral-type separation membrane module including the spiral-type separation membrane element.

  Since the spiral-type separation membrane module includes the spiral-type separation membrane element, it is possible to suppress disturbance of the stock solution flow when the stock solution is supplied. Therefore, in the spiral-type separation membrane module, concentration polarization on the surface of the separation membrane is suppressed, pressure loss is reduced, and performance degradation of the membrane element can be more effectively suppressed.

  The supply pressure of the stock solution to the spiral separation membrane element is preferably 1 MPa or less. In such a spiral separation membrane module, since the supply pressure of the stock solution is relatively small, the running cost can be reduced.

[Details of the embodiment of the present invention]
Hereinafter, a spiral separation membrane element (hereinafter also referred to as “membrane element”) and a spiral separation membrane module of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to the claim are included.

[Spiral type separation membrane module]
The spiral-type separation membrane module 1 of FIG. 1 has a membrane element 3 accommodated in a pressure vessel 2.

<Pressure vessel>
The pressure vessel 2 includes a cylindrical body 20 that is open at both ends, and closing members 21 and 22 that close the opening of the cylindrical body 20.

(Cylinder)
The diameter and length of the cylindrical body 20 are not particularly limited as long as the membrane element 3 can be appropriately accommodated, and may be appropriately selected according to the application. The cylindrical body 20 is preferably formed of a material having high pressure resistance. Examples of highly pressure-resistant materials include polyolefins such as polypropylene and polyethylene, ABS resins, polyvinyl chloride, polycarbonates, acrylic resins, polysulfones, polyacetals, polyimides, modified polyphenylene oxides, fluorine resins such as polytetrafluoroethylene, etc. Examples thereof include resin materials, fiber reinforced plastics, metal materials such as stainless steel, brass, copper, and iron, and ceramic materials.

(Occlusion member)
The closing member 21 has a header portion 23 and a stock solution port 24. The header part 23 is formed by the end plate 21A and the side wall 21B. The inside of the stock solution port 24 communicates with the header portion 23. On the other hand, the closing member 22 has a header portion 25 and a concentrate port 26. The header part 25 is formed by the end plate 22A and the side wall 22B. The inside of the concentrate port 26 communicates with the header portion 25. Examples of the material of the closing members 21 and 22 include the same materials as the cylindrical body 20.

<Membrane element>
As shown in FIGS. 2 and 3, the membrane element 3 includes a membrane leaf 4, a stock solution channel material 5, a liquid collection pipe 6, and telescope prevention plates 7 </ b> A and 7 </ b> B. In this membrane element 3, telescope prevention plates 7 A and 7 B are fixed to end surfaces 31 and 32 of a wound body 30 wound around a liquid collecting pipe 6 so as to be sandwiched between stock solution flow path materials 5 between membrane leaves 4. Is.

(Membrane leaf)
The membrane leaf 4 is wound around the liquid collecting tube 6 together with the raw solution channel material 5. The membrane leaf 4 has a separation membrane 40 and a permeate channel material 41.

(Separation membrane)
The separation membrane 40 separates unnecessary components in the stock solution. As shown in FIG. 4, the separation membrane 40 has a three-side seal bag shape in which an opening 44 is formed by a pair of separation membrane elements 42 and 43. Such a separation membrane 40 is formed in a bag shape by, for example, folding a sheet-like separation membrane and bonding both side edges continuous with the folded edge. The separation membrane 40 may be formed in a three-side seal bag shape by overlapping a pair of separation membranes and bonding three side edges.

  The separation membrane 40 may be selected from known ones according to the use of the spiral separation membrane module 1 and the like. Examples of the separation membrane 40 include a reverse osmosis membrane, a nanofiltration membrane, an ultrafiltration membrane, and a microfiltration membrane. As the separation membrane 40, a nonwoven fabric can also be used.

  As the nonwoven fabric in this case, it is possible to use a cloth obtained by bonding and processing resin fibers to each other by mechanical operation, adhesive or heat fusion between resin fibers.

  Examples of the resin fibers include polyolefin fibers such as polyethylene, polypropylene, polystyrene, and ethylene-propylene copolymer, and fluororesin fibers such as polytetrafluoroethylene, polytrifluoroethylene, polychlorotrifluoroethylene, and polyvinylidene fluoride. Examples thereof include polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, and cellulose. As the resin fibers, fibers made of two or more different resin materials may be used. The width of the resin fiber is usually 1 mm or less, preferably 100 μm or less, more preferably 5 μm or less, further preferably 1 μm or less, and most preferably 0.3 μm or less. The length of the resin fiber is preferably 10 times or more the fiber width.

The nonwoven fabric preferably has a porosity of 90% to 96%, a thickness of 0.10 mm to 0.50 mm at a basic mass of 30 g / m ² , and a tensile strength of 0.7 to 1.3 (kg / m). 25 mm), the elongation is preferably 25% to 50%, the air permeability is preferably 23 to 135 (cc / cm ² / sec), and the maximum pore diameter is preferably 1 μm to 35 μm. Oil-water separation can be appropriately performed by using a nonwoven fabric having such characteristics.

  Here, the “porosity” is a theoretical value calculated from the volume and density. “Air permeability (air permeability)” is a value measured according to JIS L 1096 A method (fragile type method): 2010 “Fabric and knitted fabric test method”. The “maximum pore diameter” is a value measured according to JIS K 3832: 2011 “Bubble point test method for microfiltration membrane elements and modules”.

(Permeate channel material)
As shown in FIG. 5, the permeate passage material 41 functions as a spacer between the separation membrane elements 42 and 43 by being accommodated inside the separation membrane 40. That is, the permeate channel material 41 defines a permeate channel between the separation membrane elements 42 and 43 in the membrane leaf 4. A porous material can be used as the permeate channel material 41. Examples of the porous body include a knitted fabric such as tricot.

<Material flow channel material>
The undiluted solution channel material 5 is positioned between the two membrane leaves 4 when wound around the liquid collecting pipe 6 together with the membrane leaf 4, and serves as a spacer between these membrane leaves 4 (separation membrane elements 42, 43). It functions. That is, the stock solution channel material 5 is laminated on the membrane leaf 4 to define a stock solution channel between the membrane leaves 4 (separation membrane elements 42 and 43).

  As shown in FIG. 6 and FIG. 7, the stock solution flow path member 5 has a plurality of first constituent yarns 51 and a plurality of second constituent yarns 52 intersecting with these first constituent yarns 51, and these are plural. Are integrated at a crossing portion 53. The stock solution flow path member 5 (mesh spacer) has linear portions 54 and 55 located between the intersecting portions 53 in the first constituent yarn 51 and the second constituent yarn 52.

  The intersecting portion 53 bulges in the thickness direction with respect to the linear portions 54 and 55, and is in contact with the membrane leaf 4 (separation membrane elements 42 and 43) at the apex portion. The intersecting portion 53 is preferably integrated by the first constituent yarn 51 and the second constituent yarn 52 being fused. Since the intersecting portion 53 is integrated, the strength of the intersecting portion 53 can be increased.

  The linear portions 54 and 55 are not in contact with the membrane leaf 4 (separation membrane elements 42 and 43) and are separated from the membrane leaf 4 (separation membrane elements 42 and 43). Examples of the cross-sectional shape of the linear portions 54 and 55 include a circle, an ellipse, a semicircle, and a polygon.

  The average minimum diameters T1 of the linear portions 54 and 55 of the first component yarn 51 and the second component yarn 52 are smaller than the average maximum thickness T2 of the intersecting portion 53, respectively. The deviation dT in the thickness direction with respect to the center O1 in the thickness direction of the intersecting portion 53 of the axial cores L1, L2 of the linear portions 54, 55 of the first constituting yarn 51 and the second constituting yarn 52 is the average of the intersecting portion 53, respectively. It is less than half of the difference between the maximum thickness T2 and the average minimum diameter T1 of the linear portions 54 and 55. The upper limit of the deviation amount dT of each of the first component yarn 51 and the second component yarn 52 is preferably 30%, and more preferably 10%. When the amount of deviation dT exceeds the upper limit, the distance between the linear portions 54 and 55 and the separation membrane 40 is reduced, and the flow of the raw solution is likely to be disturbed when the raw solution is supplied. There is a possibility that the performance degradation of the membrane element 3 due to an increase in pressure loss or the like cannot be sufficiently suppressed.

  As a minimum of average minimum diameter T1 of linear parts 54 and 55 of the 1st constituent yarn 51 and the 2nd constituent yarn 52, 20% of average maximum thickness T2 of intersection part 53 is preferred, respectively, and 30% is more preferred. On the other hand, the upper limit of the average minimum diameter T1 is preferably 60% of the average maximum thickness T2, and more preferably 50%. When the average minimum diameter T1 of the linear portions 54 and 55 is less than the lower limit with respect to the average maximum thickness T2 of the intersecting portion 53, the strength of the linear portions 54 and 55 may not be sufficiently secured. On the other hand, when the average minimum diameter T1 of the linear portions 54 and 55 exceeds the upper limit with respect to the average maximum thickness T2 of the intersecting portion 53, the distance between the linear portions 54 and 55 and the separation membrane 40 is reduced. The disturbance of the stock solution is likely to occur, and there is a possibility that the performance degradation of the membrane element 3 due to concentration polarization on the surface of the separation membrane 40 or an increase in pressure loss cannot be sufficiently suppressed.

  In order to sufficiently suppress the performance degradation of the membrane element 3, the average minimum diameter T1 of the linear portions 54 and 55 and the average maximum thickness T2 of the intersecting portion 53 are preferably set in the following ranges. That is, the lower limit of the average minimum diameter T1 of the linear portions 54 and 55 is preferably 0.1 mm, and more preferably 0.2 mm. The upper limit of the average minimum diameter T1 is preferably 0.4 mm, and more preferably 0.3 mm. As a minimum of average maximum thickness T2 of intersection part 53, 0.2 mm is preferred and 0.5 mm is more preferred. The upper limit of the average maximum thickness T2 is preferably 1.2 mm, and more preferably 1.0 mm.

  The lower limit of the average center distance D between the two intersecting portions 53 adjacent to the axial directions A1 and A2 of the first constituting yarn 51 or the second constituting yarn 52 among the plurality of intersecting portions 53 is preferably 2 mm. More preferred. On the other hand, the upper limit of the average center distance D is preferably 6 mm, and more preferably 5 mm. If the average center-to-center distance D of the intersecting portion 53 is less than the lower limit, the volume occupied by the intersecting portion 53 between the separation membrane elements 42 and 43 increases, and the stock solution flow is likely to be disturbed, which may increase the pressure loss. There is. On the other hand, when the average center distance D of the intersecting portion 53 exceeds the above upper limit, the stock solution channel material 5 may not function sufficiently as a spacer.

  The linear portions 54 and 55 of the first component yarn 51 or the second component yarn 52 may be extended in the axial directions A1 and A2 of the first component yarn 51 or the second component yarn 52. By extending the linear portions 54 and 55, the axial cores L 1 and L 2 of the linear portions 54 and 55 of the constituent yarns 51 and 52 can be brought close to the center O 1 in the thickness direction of the intersecting portion 53 and linear. The thickness of the portions 54 and 55 can be reduced. Therefore, according to the membrane element 3, the linear portions 54, 55 can be separated from the separation membrane 40, so that disturbance of the stock solution flow is suppressed, and the performance degradation of the membrane element 3 due to concentration polarization, pressure loss, etc. is further reduced. It can be effectively suppressed.

  As the 1st constituent yarn 51 and the 2nd constituent yarn 52, what has polypropylene, polyethylene, or crosslinked polyethylene as a main ingredient is mentioned, for example. Since the constituent yarn mainly composed of such a resin is available at a relatively low cost and has a relatively low melting point and can be easily processed, the material cost of the undiluted solution channel material 5 can be suppressed. .

  Such a raw material flow path material 5 can be formed by, for example, fusing the first constituent yarn 51 and the second constituent yarn 52 in an intersecting state. The first constituent yarn 51 and the second constituent yarn 52 are fused by a known method, for example, using an extrusion molding machine, the first constituent yarn 51 and the second constituent yarn 52 intersect with each other. Thus, it can carry out by carrying out extrusion formation simultaneously. After fusing, if necessary, the intersecting portion 53 may be fused by heating, and the first constituent yarn or the second constituent yarn may be stretched as necessary. The undiluted flow channel material 5 may also fuse the intersecting portion 53 by heating the first constituent yarn 51 and the second constituent yarn 52 after plain weaving or twill weaving. Such a fusing method is useful when the first constituent yarn 51 and the second constituent yarn 52 are mainly composed of a low melting point resin.

(Collection tube)
As shown in FIGS. 2 and 3, the liquid collection tube 6 is for collecting the permeate inside the membrane leaf 4 that has passed through the separation membrane 40. The liquid collection pipe 6 has a hollow shape with one end closed. A through-hole group including a plurality of through-holes 60 is formed in the liquid collection pipe 6 in a line in the axial direction of the liquid collection pipe 6. The membrane leaf 4 is fixed to the liquid collecting pipe 6 in a state where the opening 44 of the separation membrane 40 is aligned with the through hole group, and the opening 44 and the through hole 60 communicate with each other. Therefore, only the permeated liquid that has passed through the separation membrane 40 is supplied to the through holes 60 of the through hole group.

(Telescope prevention plate)
As shown in FIGS. 1 and 2, the telescope prevention plates 7A and 7B are configured as spokes. The telescope prevention plates 7A and 7B include inner peripheral ring portions 70A and 70B, outer peripheral ring portions 71A and 71B, and spoke portions 72A and 72B. Inner ring portions 70A and 70B are portions into which the liquid collection pipe 6 is fitted. Grooves 73A and 73B are provided on the outer peripheral surfaces of the outer peripheral ring portions 71A and 71B. The grooves 73A and 73B are portions into which the brine seals 74A and 74B are fitted. The brine seals 74A and 74B are for preventing the stock solution from flowing into the gap between the cylindrical body 20 and the membrane element 3. The spoke parts 72A and 72B connect the inner ring parts 70A and 70B and the outer ring parts 71A and 71B. The space surrounded by the inner ring portions 70A and 70B, the outer ring portions 71A and 71B, and the spoke portions 72A and 72B allows passage of the stock solution.

  Examples of the material of the telescope prevention plates 7A and 7B include polyethylene, polypropylene, ultrahigh molecular weight polyethylene, polyacetal, polyimide, hard polyvinyl chloride, polycarbonate, polysulfone, acrylic resin, ABS resin, modified polyphenylene oxide, polyether ketone, and the like. Resin materials and metal materials such as stainless steel.

<Method for separating stock solution>
Next, a method for separating a stock solution using the spiral separation membrane module 1 will be described. In addition, the arrow in FIG. 1 has shown the moving direction of the liquid.

  As shown in FIG. 1, the stock solution A is supplied from the stock solution port 24 to the spiral separation membrane module 1. The stock solution supply pressure to the spiral separation membrane module 1 may be determined according to the type of the separation membrane 40 of the membrane leaf 4. For example, when an oil-water separation membrane such as a nonwoven fabric is used as the separation membrane 40, the stock solution supply pressure is preferably 1 MPa or less.

  The stock solution A supplied from the stock solution port 24 passes through the header portion 23 of the blocking member 21 and the telescope prevention plate 7 </ b> A, and is supplied from the end surface 31 of the wound body 30 to the wound body 30. The stock solution A supplied to the wound body 30 moves toward the end surface 32 of the wound body 30 through the stock solution channel defined between the membrane leaves 4 (separation membrane elements 42 and 43) by the stock solution channel material 5. To do.

  The stock solution A moving through the stock solution flow path is separated by the separation membrane 40 in the moving process. The permeate B that has permeated through the separation membrane 40 moves to the inside of the separation membrane 40 (membrane element 3). The permeate B inside the separation membrane 40 moves to the permeate channel defined by the permeate channel material 41, passes through the through-hole 60, and moves to the inside of the liquid collection pipe 6. The permeate B in the liquid collection pipe 6 moves through the liquid collection pipe 6 and is collected from the end of the liquid collection pipe 6.

  On the other hand, the stock solution A that has not permeated through the separation membrane 40 is discharged from the end face 32 of the membrane element 3 and finally passes through the telescope prevention plate 7B and the header portion 25 of the closing member 22 via the concentrate port 26. Then, the concentrated liquid C is discharged to the outside of the spiral separation membrane module 1.

<Advantages>
According to the membrane element 3, the first constituent yarn 51 and the second constituent yarn 52 of the undiluted liquid channel material (mesh spacer) 5 are integrated at the intersection portion 53, and a linear portion between the adjacent intersection portions 53 is obtained. The average minimum diameter T1 of 54, 55 is smaller than the average maximum thickness T2 of the intersecting portion 53, and the intersections of the axial cores L1, L2 of the linear portions 54, 55 of the first constituent yarn 51 and the second constituent yarn 52 in the thickness direction. The amount of deviation dT with respect to the center of the portion 53 is set to be equal to or less than half of the difference between the average maximum thickness T2 of the intersecting portion 53 and the average minimum diameter T1 of the linear portions 54 and 55. Therefore, the undiluted flow channel material 5 is configured to contact the separation membrane 40 at the intersecting portion 53, and the linear portions 54 and 55 of the first component yarn 51 and the second component yarn 52 do not contact the separation membrane 40. Is possible. Therefore, by reducing the contact area between the linear portions 54 and 55 of the first constituent yarn 51 and the second constituent yarn 52 and the separation membrane 40, the surface of the separation membrane 40 caused by disturbance of the stock solution flow when the stock solution is supplied. Can suppress concentration polarization and reduce pressure loss. Thereby, in the said spiral type separation membrane module 1, a performance fall can be suppressed effectively.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and can be variously changed.

  For example, the number of the membrane leaves 4 wound around the liquid collection pipe 6 is not limited to four as shown in FIG. 3, and may be other than four, or may be one.

  The membrane leaf 4 and the undiluted solution channel material 5 are not limited to the case where the membrane leaf 4 and the stock solution flow path member 5 are wound around one place of the liquid collecting pipe 6, and may be wound around a plurality of places so as to be aligned in the axial direction of the liquid collecting pipe 6.

  In the above embodiment, the raw material flow path material 5 has one constituent thread 51 (52) along the circumferential direction of the liquid collecting pipe 6 and the other constituent thread 52 (51) along the axial direction of the liquid collecting pipe 6. However, the undiluted flow path material 5 is collected so that each of the first constituent yarn and the second constituent yarn obliquely intersects both the circumferential direction and the axial direction of the liquid collecting tube 6. It may be wound around the liquid pipe 6.

  According to the present invention, it is possible to suppress the concentration polarization on the surface of the separation membrane and reduce the pressure loss by suppressing the disturbance of the stock solution flow when the stock solution is supplied. Therefore, in the spiral separation membrane element and the spiral separation membrane module provided by the present invention, the performance degradation of the membrane element is effectively suppressed.

DESCRIPTION OF SYMBOLS 1 Spiral type separation membrane module 2 Pressure vessel 20 Cylindrical body 21 and 22 Closure member 21A, 22A End plate 21B, 22B Side wall 23, 25 Header part 24 Stock solution port 26 Concentrate port 3 Membrane element 30 Rolling body 31, 32 End face 4 Membrane leaf 40 Separation membrane 41 Permeate channel material 42, 43 Separation membrane element 44 Opening 5 Stock solution channel material 51 First component yarn 52 Second component yarn 53 Crossing portion 54, 55 Linear portion 6 Collecting pipe 60 Through Hole 7A, 7B Telescope prevention plate 70A, 70B Inner ring portion 71A, 71B Outer ring portion 72A, 72B Spoke portion 73A, 73B Groove 74A, 74B Brine seal 8 Mesh spacer 80 Warp yarn 81 Weft yarn 82 Crossing portion 90, 91 Separation membrane A1, A2 Axial direction of constituent yarn T1 Average minimum diameter of linear portion T2 Average maximum thickness of intersecting portion L1, L2 average distance between the centers of the central dT bias amount D intersection of the thickness direction of the axis O1 intersection of the linear portion

Claims (11)

One or a plurality of separation membranes in the form of a three-side seal bag for separating the stock solution, a permeate flow path material accommodated in the separation membrane, and an opening of the separation membrane are communicated, and the permeate in the separation membrane is A spiral type separation membrane element comprising a collected liquid collection tube and one or a plurality of stock solution flow path members stacked between one or a plurality of separation membranes wound around the collection tube,
The stock solution flow path material has a plurality of first constituent yarns and a plurality of second constituent yarns that intersect these first constituent yarns, and these are integrated at a plurality of intersecting portions,
The average minimum diameter of the linear portion located between the intersecting portions in the first constituent yarn is smaller than the average maximum thickness of the intersecting portions,
The deviation in the thickness direction with respect to the center in the thickness direction of the intersecting portion of the axis of the linear portion of the first constituent yarn is the difference between the average maximum thickness of the intersecting portion and the average minimum diameter of the linear portion. Spiral type separation membrane element that is less than half.   2. The spiral separation membrane element according to claim 1, wherein the first component yarn and the second component yarn are fused at the intersection.   The spiral separation membrane element according to claim 1 or 2, wherein an average minimum diameter of the linear portion is 10% or more and 70% or less of an average maximum thickness of the intersecting portion. The average minimum diameter of the linear portion is 0.1 mm or more and 0.4 mm or less,
The spiral separation membrane element according to claim 1, 2 or 3, wherein an average maximum thickness of the intersecting portion is 0.2 mm or more and 1.2 mm or less.   The spiral separation membrane element according to any one of claims 1 to 4, wherein a linear portion of the first constituent yarn is extended in an axial direction of the first constituent yarn.   The spiral type separation according to any one of claims 1 to 5, wherein an average minimum diameter of linear portions located between the intersecting portions in the second constituent yarn is smaller than an average maximum thickness of the intersecting portions. Membrane element.   The spiral separation membrane element according to any one of claims 1 to 6, wherein the separation membrane is a nonwoven fabric.   The average center distance between two intersecting portions adjacent in the axial direction of the first component yarn or the second component yarn among the plurality of intersecting portions is 2 mm or more and 6 mm or less. The spiral separation membrane element according to any one of the above.   The spiral separation membrane element according to any one of claims 1 to 8, wherein the first component yarn and the second component yarn are mainly composed of polypropylene, polyethylene, or crosslinked polyethylene.   A spiral separation membrane module comprising the spiral separation membrane element according to claim 1.   The spiral separation membrane module according to claim 10, wherein the supply pressure of the stock solution to the spiral separation membrane element is 1 MPa or less.

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