JP5458003B2 - Spiral membrane element and separation membrane module - Google Patents

Description

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

  Conventionally, for example, a spiral membrane element used for seawater desalination or ultrapure water production is known. For example, Patent Document 1 discloses a separation membrane module 10 using a spiral membrane element 12 as shown in FIGS. 4 and 5. In the separation membrane module 10, a plurality of spiral membrane elements 12 are inserted in a row in a cylindrical pressure vessel 11. Then, as shown by arrows in FIG. 4, when raw water is supplied into the pressure vessel 11 from one end of the separation membrane module 10, the raw water is concentrated with permeated water by the separation membrane of the spiral membrane element 12. They are separated into water and discharged separately from the other end of the separation membrane module 10.

  Each spiral membrane element 12 includes a laminated body including a separation membrane wound around a central tube, and a pair of end members 13 arranged with the laminated body interposed therebetween. In the separation membrane module 10 shown in FIG. 4, the upstream end member 13 seals the gap between the spiral membrane element 12 and the inner peripheral surface of the pressure vessel 11 using the upstream pressure of the raw water. A letter-shaped packing 15 is attached.

  The packing 15 has an outer diameter equivalent to the diameter of the inner peripheral surface of the pressure vessel 11 even in a natural body where no upstream pressure acts. For this reason, conventionally, when the spiral membrane element 12 is inserted into the pressure vessel 11, the spiral membrane is rubbed against the inner peripheral surface of the pressure vessel 11 while the packing 15 crushed by the dead weight of the spiral membrane element 12 is rubbed. The element 12 was pushed into the pressure vessel 11.

  Conventionally, spiral membrane elements having an outer diameter of 8 inches have been the mainstream, but in recent years, large spiral membrane elements having an outer diameter of 16 to 24 inches have been developed. However, in such a large spiral membrane element, the contact area between the inner peripheral surface of the pressure vessel and the packing increases, and the weight of the spiral membrane element increases.

  Therefore, in Patent Document 1, in order to easily insert the spiral membrane element 12 into the pressure vessel 11, as shown in FIGS. 4 and 5, the inner circumferential surface of the pressure vessel 11 is arranged on the inner circumferential surface. It has been proposed to provide a pair of rails 17 and the like protruding from the surface to reduce the frictional resistance when the spiral membrane element 12 is inserted.

JP 2009-220104 A

  However, when the rail 17 protruding from the inner peripheral surface is provided on the inner peripheral surface of the pressure vessel 11 as shown in FIGS. 4 and 5, the spiral membrane element 12 is inserted into the pressure vessel 11. In addition, the packing 15 rubs against the rail 17 with the top of the rail 17 biting into the packing 15. For this reason, there is a possibility that the packing 15 may be damaged due to local wear of the packing 15.

  In view of such circumstances, the present invention provides a spiral membrane element that can be easily inserted into a pressure vessel having an inner peripheral surface without irregularities, and a separation membrane module using the spiral membrane element. For the purpose.

  In order to solve the above-described problems, the present invention provides a spiral membrane element inserted into a cylindrical pressure vessel, a central tube, and a separation membrane and a channel wound around the central tube A laminate including a material, a pair of end members fixed to both ends of the central tube so as to sandwich the laminate, and an annular seal member attached to one of the pair of end members, Provided is a spiral membrane element in which a rotating body that protrudes from the outer peripheral surface and that can roll at least in the axial direction of the central tube is attached to the outer peripheral surface of each of the pair of end members.

  Further, the present invention includes a cylindrical pressure vessel and a plurality of spiral membrane elements inserted into the pressure vessel, and each of the plurality of spiral membrane elements includes the spiral membrane element described above. A separation membrane module is provided.

  According to the above configuration, the weight of the spiral membrane element can be received by the rotating body attached to the end member. Therefore, even if the pressure vessel has an inner peripheral surface without unevenness, the spiral membrane element can be smoothly inserted by bringing the rotating body into contact with the inner peripheral surface of the pressure vessel.

Sectional drawing of the separation membrane module using the spiral membrane element which concerns on one Embodiment of this invention Configuration of spiral membrane element shown in FIG. (A) is a partially sectional side view of an end member, and (b) is a front view thereof. Cross-sectional view of a separation membrane module using a conventional spiral membrane element Sectional drawing in the direction orthogonal to FIG. 4 of the separation membrane module shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description relates to an example of the present invention, and the present invention is not limited to these.

  FIG. 1 shows a separation membrane module 1 using a spiral membrane element 2 according to an embodiment of the present invention. The separation membrane module 1 includes a cylindrical pressure vessel 7 called a vessel and a plurality of spiral membrane elements 2 inserted into the pressure vessel 7.

  Disc-shaped caps 8 and 9 are attached to both ends of the pressure vessel 7. On one side (left side in FIG. 1), a supply pipe 81 for supplying raw water into the pressure vessel 7 is provided at a position shifted from the center. The other (right side in FIG. 1) cap 9 is provided with a first discharge pipe 91 for taking out permeate at the center, and a second discharge pipe 92 for taking out concentrated water at a position shifted from the center. Is provided. That is, a flow of raw water from one cap 8 toward the other cap 9 is formed in the pressure vessel 7. The supply pipe 81 and the second discharge pipe 92 may be provided in the pressure vessel 7.

  In the present embodiment, a reverse osmosis membrane element is used as the spiral membrane element 2. However, the spiral membrane element 2 may be an ultrafiltration membrane element, for example.

  Each spiral membrane element 2 is fixed to both ends of the central tube 21 so as to sandwich the laminated body 22 between the central tube 21 functioning as a water collecting pipe, the laminated body 22 wound around the central pipe 21, and the laminated body 22. A pair of end members 3 and an exterior material 28 surrounding the laminate 22 are provided. The pair of end members 3 also serves to prevent the laminate 22 from extending in a telescopic manner.

  In the present embodiment, the upstream end member 3 of the pair of end members 3 is provided with an annular seal member with a gap between the spiral membrane element 2 and the inner peripheral surface 7a of the pressure vessel 7 on the upstream side of the raw water. A packing 5 having a substantially U-shaped cross section for sealing using pressure is mounted. However, the sealing member of the present invention is not limited to the packing 5, and has any shape as long as it can seal the gap between the spiral membrane element 2 and the inner peripheral surface 7 a of the pressure vessel 7. You may do it.

  In the present embodiment, each end member 3 is fixed to the central tube 21 so that their end faces substantially coincide with each other, and when the adjacent spiral membrane elements 2 are connected to each other by the connector 61, the end members The three are in close contact with each other. A plug 62 is attached to the central pipe 21 of the membrane element 2 located on the most upstream side, and the central pipe 21 of the membrane element 2 located on the most downstream side is connected to the first discharge pipe 91 by the second connector 63. Connected.

  As shown in FIG. 2, the central tube 21 is formed with a plurality of introduction holes through which filtered water flows.

  The laminated body 22 has a rectangular shape in which the winding direction is one opposite side direction, and a membrane member in which separation membranes 23 are overlapped on both surfaces of the permeate channel material 24 and the raw water channel material 25. Including. In the membrane member, the separation membranes 23 are joined to each other at three sides so as to have a bag shape opened in one direction, and the opening communicates with the introduction hole of the central tube 21. The permeate flow path member 24 is a net made of, for example, a resin, and forms a flow path for allowing permeate to flow between the separation membranes joined to each other. The raw water channel material 25 is, for example, a net made of resin (a net having a mesh size larger than that of the permeated water channel material 24), and forms a channel for flowing raw water between the surrounding portions of the wound membrane member. To do.

  Examples of the material constituting the separation membrane 23 include aromatic polyamides excellent in pressure reduction, polyvinyl alcohols excellent in permeability, and sulfonated polyether sulfones suitable for nanofiltration membranes.

  The pair of end members 3 have the same shape. Specifically, as shown in FIGS. 3A and 3B, each end member 3 separates the inner cylinder portion 31 and the inner cylinder portion 31 that are fitted to the end portion of the central tube 21 from the outside. The inner cylinder part 31 and the outer cylinder part 32 which are concentric are included. The outer peripheral surface 32 a of the outer cylindrical portion 32 constitutes the outer peripheral surface of the end member 3. In the following, for convenience of explanation, the right side (the direction in which the end member 3 faces the side opposite to the laminate 22) in FIG. 3A is the front side, and the left side (the direction in which the end member 3 faces the side of the laminate 22). Is called the rear.

  A holding groove 33 extending in the circumferential direction is formed in the outer peripheral surface 32 a of the outer cylindrical portion 32 and into which the packing 5 is inserted. Further, on the outer peripheral surface 32 a, a flange portion 38 that restricts the axial movement of the exterior material 28 is connected to the rear side surface of the pair of side surfaces that form the holding groove 33, behind the holding groove 33. It is provided as follows. The flange portion 33 protrudes radially outward from a portion of the outer peripheral surface 32a that is forward of the holding groove 33, and defines the maximum diameter of the outer peripheral surface 32a. The outer cylinder portion 32 is provided with a guide portion 37 that holds the exterior material 28 from the inside. The guide portion 37 may be a skirt that holds the exterior material 28 from the outside.

  A groove may be formed on the front end surface of the outer cylindrical portion 32 so as to connect the inner peripheral surface 32 b and the outer peripheral surface 32 a of the outer cylindrical portion 32. If such a groove is formed, even if the end members 3 are in close contact with each other, a flow port 30 (described later) penetrating the end member 3 is provided between the end members 3 and the membrane element 2 and the pressure vessel 7. A flow path communicating with the space between the peripheral surface 7a is secured. As a result, the raw water that has passed through the spiral membrane element 2 is guided to the periphery of the spiral membrane element 2, so that a large pressure difference occurs inside and outside the spiral membrane element 2 at the start of operation when the pressure of the raw water suddenly increases. Can be prevented, and the spiral membrane element 2 can be prevented from being damaged.

  A plurality of rotating bodies 4 projecting from the outer peripheral surface 32 a are attached to the outer peripheral surface 32 a of the outer cylindrical portion 32. Three or more rotating bodies 4 (eight in the illustrated example) are arranged so as to be arranged at equal angular intervals in the circumferential direction of the outer peripheral surface 32a. In the present embodiment, a ball that can roll in any direction is adopted as the rotating body 4.

  When the rotating body 4 is not provided, when the spiral membrane element 2 is inserted into the pressure vessel 7, the packing 5 is attached to the end member 3 just below the spiral membrane element 2 due to its own weight. It is crushed by a certain distance radially inward from the state of being mounted. The apex of the rotating body 4 is radially outer than the virtual circle whose radius is smaller by the predetermined distance from the outer diameter of the packing 5 just attached to the end member 3, centered on the axis of the central tube 21. Is located. That is, the rotating body 4 protrudes from the outer peripheral surface 32a so that deformation of the packing 5 due to the weight of the spiral membrane element 2 in the pressure vessel 7 can be regulated. For this reason, if the spiral membrane element 2 is inserted into the pressure vessel 7 in a posture in which one rotary body 4 is positioned on a vertical line passing through the axis of the central tube 21, You can receive your own weight.

  Further, in the rotating body 4, the spiral membrane element 2 is placed on the horizontal plane in a posture in which an intermediate point between the adjacent rotating bodies 4 is positioned on a vertical line passing through the axis of the central tube 21, and the packing 5 is deformed. When it does, it is preferable that the two rotary bodies 4 located below protrude so that the horizontal surface may contact | abut. With this configuration, the rotating body 4 can be brought into contact with a flat surface regardless of the posture of the spiral membrane element 2, and the rotating body 4 can be used when handling the spiral membrane element 2. Can be used.

  Furthermore, it is preferable that the apex of the rotating body 4 is located on a circle having the same diameter as the inner peripheral surface 7a of the pressure vessel 7 with the axis of the central tube 21 as the center. If it is in this way, the center axis | shafts can be united only by inserting the spiral type | mold membrane element 2 in the pressure vessel 7. FIG.

  The material of the rotating body 4 is not particularly limited as long as it is not eroded by raw water, and may be a metal or a resin. Among these, stainless steel is preferable, for example, from the viewpoint of receiving the weight of the spiral membrane element 2 and withstanding the operating pressure applied to the raw water.

  From the viewpoint of avoiding contact between the end member 3 and the inner peripheral surface 7a of the pressure vessel 7 with a smaller number, the number of the rotators 4 is preferably 3 to 16, and more preferably 6 to 12.

  The inner cylinder part 31 and the outer cylinder part 32 are connected by a plurality of ribs 35 at positions corresponding to the rotating body 4. That is, the rib 35 extends radially from the inner cylinder portion 31. In the present embodiment, the outer cylindrical portion 31 is provided with a plurality of protruding portions 34 that protrude radially inward at positions corresponding to the rotating body 4, and the tips of the ribs 35 are connected to the protruding portions 34. Further, in the present embodiment, the inner cylindrical portion 31 and the outer cylindrical portion 32 are connected by the second rib 36 even between the adjacent ribs 35. The rib 35 and the second rib 36 have a flat plate shape in the radial direction, and a substantially triangular shape that faces the inner peripheral surface 32 b of the outer cylindrical portion 32 between the rib 35 and the second rib 36. A columnar space is formed. And the circulation port 30 which penetrates the end member 3 and distribute | circulates raw | natural water is comprised by this space.

  A sleeve 41 is embedded in the protruding portion 34 provided on the outer cylindrical portion 32 so as to be exposed on the outer peripheral surface 32a. The sleeve 41 is formed with a screw shaft 41 that protrudes on the opposite side of the rotating body 3, and the screw shaft 41 is screwed into a screw hole 32 c formed in the protrusion 34, whereby the sleeve 41 is protruded. 34 is fixed. The sleeve 41 holds the rotating body 4, and a plurality of balls (not shown) that support the rotating body 4 are arranged in the sleeve 41.

  In the spiral membrane module 2 of this embodiment, the rotating membrane 4 attached to the end member 3 can receive the weight of the spiral membrane element 2. Therefore, even if the pressure vessel 7 has the inner peripheral surface 7a without unevenness, the spiral membrane element 2 can be smoothly inserted by bringing the rotating body 4 into contact with the inner peripheral surface 7a of the pressure vessel 7. .

  In the present embodiment, three or more rotating bodies 4 are arranged at equal angular intervals in the circumferential direction of the outer peripheral surface 32a. For this reason, when one rotating body 4 is positioned on a vertical line passing through the axis of the central tube 21, the packing 5 is excessively pressed against the inner peripheral surface 7 a of the pressure vessel 7 on both sides of the rotating body 4. Can be prevented. Further, when the intermediate point between the adjacent rotating bodies 4 is positioned on the vertical line passing through the axis of the central tube 21, the insertion of the spiral membrane element 2 can be guided by the two rotating bodies 4. Therefore, in any case, the spiral membrane element 2 can be more easily inserted into the pressure vessel 7.

  Further, since the outer cylindrical portion 32 and the inner cylindrical portion 33 of the end member 3 are connected by the rib 35 at a position corresponding to the rotating body 4, no matter which rotating body 4 is positioned below, the spiral membrane element The end member 3 can be given sufficient strength to withstand the weight of 2.

  In addition, the outer cylindrical portion 32 is provided with a protruding portion 34 that protrudes radially inward, and a sleeve 41 that holds the rotating body 4 is embedded in the protruding portion 34, so that the area of the circulation port 30 is as large as possible. However, the end member 3 can be provided with a mechanism for rotatably supporting the rotating body 4.

<Modification>
In the embodiment, the end member 3 is fixed to the central tube 21 so that the end surfaces thereof coincide with each other. However, the end member 3 is fixed to the central tube 21 so as to be located inside the end surface of the central tube 21. May be. In this case, when adjacent spiral membrane elements 2 are connected to each other, a gap is formed between the end members 3, and the raw water that has passed through the spiral membrane element 2 by this gap is supplied to the spiral membrane element 2. Since the flow path leading to the periphery is configured, it is not necessary to form a groove on the end surface of the end member 3.

  The rotating body 4 only needs to be able to roll at least in the axial direction of the central tube 21, and may be a roller that can roll only in the axial direction of the central tube 21, for example.

  Further, if there are two rotating bodies 4, the spiral membrane element 2 can be self-supported on the inner peripheral surface 7 a of the pressure vessel 7, and therefore it is not always necessary that three or more are arranged at equal angular intervals. . That is, at least two rotating bodies 4 may be arranged in the circumferential direction of the outer peripheral surface 32a so as to be separated from each other within an angle range of 90 degrees, for example.

  Alternatively, when a roller is employed as the rotating body 4, the number of the rotating bodies 4 may be one because the lateral oscillation of the spiral membrane element 2 with the rotating body 4 as a fulcrum can be suppressed to some extent. .

  Further, the rotating body 4 (ball or roller) does not need to be supported by a plurality of balls. For example, a spring is provided in the sleeve 41 so that the rotating body 4 can be retracted radially inward by the spring. It may be energized.

DESCRIPTION OF SYMBOLS 1 Separation membrane module 2 Spiral type | mold membrane element 21 Center pipe 22 Laminated body 23 Separation membrane 24 Permeate flow path material 25 Raw water flow path material 3 End member 31 Inner cylinder part 32 Outer cylinder part 32a Outer peripheral surface 34 Projection part 35 Rib 4 Rotating body 41 Sleeve 5 Packing (seal member)
7 Pressure vessel 7a Inner peripheral surface

Claims (6)

A spiral membrane element inserted into a cylindrical pressure vessel,
A central tube,
A laminate including a separation membrane and a channel material wound around the central tube;
A pair of end members fixed to both ends of the central tube so as to sandwich the laminate;
An annular seal member mounted on one of the pair of end members,
On each outer peripheral surface of the pair of end members, a rotating body protruding from the outer peripheral surface and capable of rolling at least in the axial direction of the central tube is attached ,
At least two of the rotating bodies are arranged so as to be separated from each other in the circumferential direction of the outer peripheral surface,
Each of the pair of end members includes an inner cylindrical portion that fits into the central tube, an outer cylindrical portion that surrounds the inner cylindrical portion while being separated, and the inner cylindrical portion and the outer portion at positions corresponding to the rotating body. Having a plurality of ribs connecting the cylindrical portion,
Spiral membrane element. The rotating body, the are arranged to three or more arranged at equal angular intervals in the circumferential direction of the outer peripheral surface, the spiral membrane element according to claim 1. The outer cylindrical portion is provided with a plurality of protruding portions protruding radially inward at positions corresponding to the rotating body,
3. The spiral membrane element according to claim 1, wherein a sleeve for holding the rotating body is embedded in the protruding portion so as to be exposed on an outer peripheral surface of the outer cylindrical portion. The spiral membrane element according to claim 3 , wherein a plurality of balls that support the rotating body are disposed in the sleeve. Vertex of the rotating body, centered on the axis of the central tube, are located on a circle of the same diameter as the inner peripheral surface of the pressure vessel, according to claim 1 Spiral membrane element. A cylindrical pressure vessel, and a plurality of spiral membrane elements inserted into the pressure vessel,
The separation membrane module, wherein each of the plurality of spiral membrane elements is the spiral membrane element according to any one of claims 1 to 5 .

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