WO2022113613A1

WO2022113613A1 - Spiral-type membrane element and spiral-type membrane module

Info

Publication number: WO2022113613A1
Application number: PCT/JP2021/039458
Authority: WO
Inventors: 康弘宇田; 康秀岡▲崎▼; 摩耶木原
Original assignee: 日東電工株式会社
Priority date: 2020-11-25
Filing date: 2021-10-26
Publication date: 2022-06-02
Also published as: CN115461135A; TWI793832B; TW202224760A

Abstract

Provided are: a spiral-type membrane element that requires no need for glass fiber reinforcement, includes of a small number of components, and enables a reduction in bypass flow and an increase in effective membrane area; and a spiral-type membrane module. A spiral-type membrane element E according to the present invention comprises: a perforated center tube 5; a roll body R that includes a separation membrane 1 and is wound around the center tube 5; and a cladding disposed on the outer circumference of the roll body R. The cladding includes an external flow channel material 21 that forms a flow channel outside the roll body R while blocking inflow of feed liquid 7 by covering the outer circumference of the roll body R. It is preferable for the external flow channel material 21 to comprise: a sheet material 21a for covering the outer circumference of the roll body R; and a porous material 21b that covers said sheet material 21a.

Description

Spiral type membrane element and spiral type membrane module

The present invention relates to a spiral type membrane element (hereinafter, may be abbreviated as "membrane element") and a spiral type membrane module using the spiral type membrane element.

Conventionally, in a spiral type membrane element, a flat separation membrane, a permeation side flow path material, and a supply side flow path material are wound around a perforated central tube, and an exterior material is wound around the outer periphery of the obtained winding body. It was manufactured by constructing FRP (fiber reinforced plastic). At that time, ATDs (Anti-telescoping devices, anti-telescope materials) attached to both ends of the membrane element were integrated at the time of FRP construction.

A U packing is attached to the ATD to prevent bypass flow from occurring between the membrane element and the vessel. When a bypass flow occurs, the supply liquid flowing through the supply-side flow path inside the membrane element is reduced by that amount, resulting in a decrease in energy efficiency consumed in the filtration process. Pressure loss occurs when the supply liquid flows through the supply-side flow path inside the membrane element, but at the outer periphery of the membrane element (between the outer peripheral surface of the membrane element and the inner surface of the vessel), the pressure changes stepwise before and after the U packing. When the U packing is attached to the upstream ATD, internal pressure acts on the exterior FRP.

The exterior FRP is usually made of GFRP (glass FRP, glass fiber FRP), and has sufficient strength because it can withstand internal pressure in the direction of being reinforced with glass fiber. If the U packing is attached to the ATD on the downstream side, the pressure acting on the exterior FRP becomes an external pressure. In this case, the cross section of the exterior FRP (the cross section orthogonal to the axial direction of the membrane element) buckles and deforms into an elliptical shape or a triangular shape, and as a result, the internal winding body is also pushed by the FRP, causing wrinkles on the membrane. Causes a problem. Therefore, the U packing was basically attached to the ATD on the upstream side.

The performance of the spiral type membrane element deteriorates over time as a result of deterioration over time and contamination of the membrane surface due to its use. Regarding the contamination of the membrane surface, it is possible to recover to a certain extent by increasing the flow velocity on the supply liquid side, which is called flushing cleaning, to physically wash away the contaminants, or by chemically cleaning by chemical cleaning. At some point, it will reach its limit and the membrane element itself will need to be replaced. The used membrane element after replacement may be reused for other purposes that do not require high performance, but most of it is disposed of. Disposal methods include landfill disposal and incineration disposal.

There are also technologies that do not assume the above-mentioned GFRP exterior materials. For example, Patent Document 1 discloses a spiral type membrane element in which the outer periphery of the wound body is covered with a permeation side flow path material. However, in the embodiment, the outer peripheral surface of the permeation side flow path material is fixed with a film tape and a brine seal (U packing) is provided. In the invention of Patent Document 1, the film tape is provided on the outer periphery of the permeation side flow path material. It is clear that this is a technique that assumes that the supply liquid exists inside and that the supply liquid flows inside.

Further, Patent Document 2 discloses that a cylindrical net-like material is provided on the outer periphery of the winding body in place of the GFRP exterior material as described above, but the present invention also seals the ATD of the membrane element. It is premised that a material (U packing) is provided.

Japanese Unexamined Patent Publication No. 2019-205954 Japanese Unexamined Patent Publication No. 2000-354742

By the way, the treatment of the membrane element after replacement is a big problem, and the volume of the treatment plant is finite in the landfill disposal, and the membrane element, which is mostly made of plastic material, is not decomposed in the ground, so it is semi-permanent. It is not a sustainable treatment method as it will remain in the ground. Further, since the glass fiber contained in the exterior FRP does not burn, the glass fiber remains in the incinerated ash after incineration, which makes the treatment of the incinerated ash difficult.

As described in Patent Document 1, when the film tape is used as the exterior material and the packing is provided on the upstream side of the membrane element, the glass fiber can be omitted, but the membrane element is deformed by the internal pressure and is deformed during operation or cleaning. The problem of breakage of the separation membrane may occur.

Further, as described in Patent Document 2, when a cylindrical net-like material is provided on the outer periphery of the winding body, raw water flows through a gap between the net-like material and the pressure vessel on the outer peripheral side to form a bypass flow. There was a problem that the filtration efficiency was lowered.

In the conventional spiral type membrane element, the winding body and the ATD are integrated by an exterior material, and the structure is provided with U packing on the outer circumference of the ATD, so that the outer diameter of the winding body is the outer diameter of the ATD. It was difficult to increase it regardless of. Moreover, such a structure has increased the number of parts.

Therefore, an object of the present invention is to provide a spiral type membrane element and a spiral type membrane module which do not require glass fiber reinforcement, have a small number of parts, can reduce bypass flow and increase the effective membrane area. ..

The above object can be achieved by the present invention as follows.

That is, the spiral type membrane element of the present invention includes a perforated central tube, a winding body wound around the central tube and containing a separation membrane, and an exterior material provided on the outer periphery of the winding body. A spiral type membrane element, wherein the exterior material includes an exterior flow path material that covers the outer periphery of the winding body to block the inflow of supply liquid and forms a flow path outside the winding body. It is a feature.

According to the spiral type membrane element of the present invention, the outer flow path material covers the outer periphery of the winding body to block the inflow of the supply liquid and forms the flow path outside the winding body, so that the inside of the winding body is formed. Since the liquid flowing through the (membrane-separated supply liquid) and the liquid flowing through the flow path of the exterior flow path material (supply liquid without membrane separation) form independent flow paths, the pressure distributions of both flow paths are independent. Can be controlled. Therefore, the pressure difference between the two channels can be reduced, and the glass fiber reinforcement becomes unnecessary. Further, even if the outer circumference of the membrane element is in close contact with the inner surface of the pressure vessel, the supply liquid can flow inside the outer flow path material, so that the effective membrane is increased by increasing the outer diameter of the winding body while reducing the bypass flow. The area can be increased. Further, since the bypass flow can be reduced, the ATD and U packing on the upstream side are not required, and the number of parts can be reduced. As a result, it is possible to provide a spiral type membrane element that does not require glass fiber reinforcement, has a small number of parts, can reduce bypass flow, and can increase the effective membrane area.

In the above, the exterior flow path material preferably contains a sheet material that covers the outer periphery of the winding body and a porous material that covers the sheet material. According to this configuration, the sheet material can cover the outer periphery of the winding body to block the inflow of the supply liquid, and the porous material can form a flow path outside the winding body. Further, by using the porous material, it becomes easier to control the pressure loss, and it becomes easier to reduce the pressure difference between the two flow paths.

Further, when it is housed in a pressure vessel and used, it is preferable that the outer diameter with respect to the outer circumference of the exterior material is 99 to 100% with respect to the inner diameter of the pressure vessel. With such an outer diameter, the gap between the exterior material and the inner surface of the pressure vessel is reduced, and the bypass flow can be reduced and the effective film area can be effectively increased.

Further, it is preferable to provide a removable anti-telescope material on the downstream side of the winding body. By making the anti-telescope material for suppressing the telescope removable, the amount of waste treated can be reduced and the anti-telescope material can be reused. In addition, the process of integrating the anti-telescope material with the exterior material becomes unnecessary, and the mounting process becomes simple.

At that time, the anti-telescope material includes an outer peripheral side obstruction plate arranged on the downstream side near the outer periphery of the winding body and an inner peripheral side obstruction plate arranged on the downstream side near the inner circumference of the winding body. It is preferable that and is provided. Although the detailed reason will be described later, there is a concentration distribution in the concentrated liquid flowing out from the spiral type membrane element, and the concentration becomes small near the outer circumference and the inner circumference of the winding body. In the present invention, the outer flow path material covering the winding body flows through the outer flow path material without the supply liquid being concentrated, so that the concentration of the concentrated liquid becomes smaller near the outer periphery than usual. A low concentration means that the osmotic pressure is low, and it is efficient to flow the part that does not separate the membrane even in the next stage even though it is a supply liquid that can expect a high flux (Flux) if it flows through the membrane surface. Not the target. Therefore, by providing the outer peripheral side baffle plate and the inner peripheral side baffle plate, the concentrated liquid can be stirred and mixed, and the efficiency of membrane separation in the next stage can be improved.

It is preferable that the anti-telescope material is attached to the central tube extending to the downstream side of the winding body. By using the central canal, the anti-telescope material can be made into a simple detachable structure.

On the other hand, the spiral type membrane module of the present invention includes the spiral type membrane element according to any one of the above and the pressure vessel accommodating the spiral type membrane element, and has an outer diameter based on the outer periphery of the exterior material. It is characterized in that it is 99 to 100% with respect to the inner diameter of the pressure vessel.

According to the spiral type membrane module of the present invention, since the outer diameter of the membrane element is set to 99 to 100% with respect to the inner diameter of the pressure vessel by using the spiral type membrane element as described above, the above-mentioned action and effect can be obtained. That is, since the outer flow path material of the film element covers the outer periphery of the winding body and blocks the inflow of the supply liquid to form a flow path outside the winding body, the liquid (film) flowing inside the winding body. Since the liquid to be separated) and the liquid flowing inside and outside the porous material (the liquid to which the membrane is not separated) form independent flow paths, the pressure distribution in both flow paths should be controlled independently. Can be done. Therefore, the pressure difference between the two channels can be reduced, and the glass fiber reinforcement becomes unnecessary. Further, even if the outer circumference of the membrane element is in close contact with the inner surface of the pressure vessel, the supply liquid can flow inside the outer flow path material, so that the effective membrane is increased by increasing the outer diameter of the winding body while reducing the bypass flow. The area can be increased. Further, since the bypass flow can be reduced, the ATD and U packing on the upstream side are not required, and the number of parts can be reduced. As a result, it is possible to provide a spiral type membrane module that does not require glass fiber reinforcement, has a small number of parts, can reduce bypass flow, and can increase the effective membrane area.

It is possible to provide a spiral type membrane element and a spiral type membrane module that do not require glass fiber reinforcement, have a small number of parts, can reduce bypass flow and increase the effective membrane area.

It is sectional drawing which shows an example of the state in which the spiral type membrane element of this invention is housed in a pressure vessel, and is a partially enlarged view. It is a top view which shows an example of the separation membrane unit used for the spiral type membrane element of this invention. It is a front view which shows an example of the separation membrane unit used for the spiral type membrane element of this invention. It is a front view which shows an example of the state before laminating and winding the separation membrane unit used for the spiral type membrane element of this invention. It is a partially cutaway perspective view which shows an example of a winding body in which a membrane leaf and a flow path material on a supply side are wound around a central canal. It is a perspective view which shows an example of the anti-telescope material which can be used for the spiral type membrane element of this invention. It is a front view which shows the other example of the state before laminating and winding the separation membrane unit used for the spiral type membrane element of this invention. It is a front view which shows the other example of the state before laminating and winding the separation membrane unit used for the spiral type membrane element of this invention. It is a front view which shows the other example of the state before laminating and winding the separation membrane unit used for the spiral type membrane element of this invention. It is a front view which shows the other example of the state before laminating and winding the separation membrane unit used for the spiral type membrane element of this invention. It is a front view which shows the other example of the anti-telescope material which can be used for the spiral type membrane element of this invention. It is a front view which shows the other example of the anti-telescope material which can be used for the spiral type membrane element of this invention. It is a front view which shows the other example of the anti-telescope material which can be used for the spiral type membrane element of this invention. It is sectional drawing which shows the main part in another example of the spiral type membrane element of this invention. It is sectional drawing which shows the main part in another example of the spiral type membrane element of this invention. It is sectional drawing which shows the main part of the other example of the spiral type membrane element of this invention. It is sectional drawing which shows the main part of the other example of the spiral type membrane element of this invention. It is sectional drawing which shows the main part of the other example of the spiral type membrane element of this invention.

(Spiral type membrane element)
As shown in FIG. 1, for example, the spiral type membrane element E of the present invention includes a perforated central tube 5, a winding body R wound around the central tube 5 and including a separation membrane 1, and the winding body R thereof. It is provided with an exterior material provided on the outer periphery of the above. As shown in FIG. 3, for example, the membrane element E includes a plurality of membrane leaves L in which the transmission side flow path material 3 is interposed between the opposing separation membranes 1, and a supply side flow path that is interposed between the membrane leaves L. The material 2 is provided with a perforated central tube 5 around which the membrane leaf L and the supply-side flow path material 2 are wound, and a sealing portion for preventing mixing between the supply-side flow path and the permeation-side flow path. Is common.

It is also possible to provide irregularities or grooves on the surface of the separation membrane 1 to form the supply side flow path and / or the transmission side flow path on the separation membrane 1 itself, in which case the supply side flow path material 2 and / or Alternatively, the permeation side flow path material 3 can be omitted.

In this embodiment, an example is shown in which the sealing portion includes both ends sealing portion 11 and the outer peripheral side sealing portion 12. Of the sealing portions, the both end sealing portions 11 are formed by sealing the two side ends of the film leaf L on both sides in the axial direction A1 with an adhesive. The outer peripheral side sealing portion 12 is formed by sealing the end portion of the outer peripheral side tip of the film leaf L with an adhesive.

Further, in the present invention, as shown in FIG. 3, it is preferable to have a central sealing portion 13 in which the perforated central tube 5 and the base end portion of the membrane leaf L are sealed with an adhesive. The membrane element of the present embodiment has a winding body R in which the membrane leaf L and the supply-side flow path material 2 are wound around the central tube 5 via such a central sealing portion 13.

The winding body R can be manufactured by, for example, the steps shown in FIGS. 2A to 2C. 2A is a plan view of the separation membrane unit U, FIG. 2B is a front view of the separation membrane unit U, and FIG. 2C is a front view showing a state before laminating and winding the separation membrane unit U. Further, FIG. 3 is a partially cutaway perspective view showing an example of a winding body R in which the membrane leaf L and the supply-side flow path material 2 are wound around the central tube 5.

First, as shown in FIGS. 2A and 2B, a material in which the supply side flow path material 2 is arranged while the separation membrane 1 is folded in half and a permeation side flow path material 3 are stacked, and both ends sealing portion 11 and the outer periphery thereof are stacked. The separation membrane unit U is prepared by applying the

adhesives

4 and 6 for forming the side sealing portion 12 to both ends of the transmission side flow path material 3 in the axial direction A1 and the tip of the winding. At this time, a protective tape may be attached to the crease portion of the separation membrane 1.

The

adhesives

4 and 6 are not particularly limited, and conventionally known adhesives can be adopted. Specifically, any conventionally known adhesive such as a urethane-based adhesive or an epoxy-based adhesive can be used.

Next, as shown in FIG. 2C, the same number of separation membrane units U as the membrane leaf L are laminated on the transmission side flow path material 3 having a portion extended from the others, and the separation membrane unit U is laminated. Prepare your body. At this time, the central side sealing portion 13 can be formed by applying the adhesive to both ends of the extension portion of the lowermost permeation side flow path material 3 in the axial direction A1.

Next, as shown in FIG. 2C, the perforated central tube 5 is rotated in the direction of the arrow, and the plurality of separation membrane units U are wound around the central canal 5. At this time, the

adhesives

4 and 6 adhere the opposing separation membrane 1 and the permeation side flow path material 3 to form a membrane leaf L having both end sealing portions 11 and outer peripheral side sealing portions 12. To.

As a result, as shown in FIG. 3, a winding body R in which the membrane leaf L and the supply-side flow path material 2 are wound around the central tube 5 is formed. The wound body R after sealing may be trimmed at both ends in order to adjust the length in the axial direction A1.

In the conventional membrane element E, an upstream end member such as a seal carrier is provided on the upstream side of the winding body R, and a downstream end member such as an anti-telescope material is constantly provided on the downstream side. However, in the membrane element E of the present invention, as shown in FIG. 1, it is not necessary to provide the upstream end member integrated with the winding body R. Further, it is preferable that the anti-telescope material 25 is not integrated with the winding body R, but is provided with the detachable anti-telescope material 25.

In a general spiral type membrane element having a diameter of 8 inches, about 15 to 30 sets of membrane leaves L are wound, but in the present invention, the outer diameter of the wound body R can be made larger than before. , The length of the film leaf L (the length perpendicular to the axial direction A1) can be made longer than before. As a result, the effective membrane area of the composite semipermeable membrane can be increased, and a large amount of treatment can be performed, so that the treatment efficiency is improved.

When the membrane element E is used, as shown in FIG. 1, it is housed in the pressure vessel 30 (vessel), and the supply liquid 7 is supplied from one end face side of the membrane element. The supplied liquid 7 flows along the supply-side flow path material 2 in a direction parallel to the axial direction A1 of the central tube 5, and is discharged as a concentrated liquid 9 from the other end face side of the membrane element. Further, the permeate liquid 8 that has permeated the separation membrane 1 in the process of flowing along the supply side flow path material 2 flows along the permeation side flow path material 3 and then flows from the opening 5a to the central tube 5. It flows into the inside and is discharged from the end of the central tube 5. The spiral membrane module shown in FIG. 1 will be described in detail later.

(Exterior material)
In the present invention, the exterior material provided on the outer periphery of the winding body R covers the outer periphery of the winding body R to block the inflow of the supply liquid 7 and forms a flow path outside the winding body R. It is characterized by including the road material 21. The exterior flow path material 21 may be composed of a single piece of the uneven sheet material 21s having protrusions and grooves on the outside, as shown in FIG. 8B, but the flow formed outside the winding body R. From the viewpoint of suitably controlling the pressure loss of the road, it is preferable to use a plurality of materials.

In the present embodiment, for example, as shown in FIG. 1, the exterior flow path material 21 provided on the outer periphery of the winding body R is a sheet material 21a that covers the outer periphery of the winding body R and a porous surface that covers the sheet material 21a. An example including the quality material 21b is shown. As described above, in the present invention, the structure can be such that the exterior FRP is omitted.

The exterior FRP has a function to withstand the internal pressure, but the porous material 21b that does not contain the reinforcing material such as glass fiber does not have the function to withstand the internal pressure, so the structure is such that the internal pressure is not easily applied. Therefore, the U packing is eliminated so that a small amount of the supply liquid 7 flows in the layer of the porous material 21b. Similar to the flow of the supply liquid 7 inside the winding body R, the supply liquid 7 also flows inside the porous material 21b outside the winding body R, so that the pressure loss in both flow paths becomes substantially the same, and the winding Neither the internal pressure nor the external pressure acts on the sheet material 21a that covers the outer periphery of the body R.

That is, as shown in the enlarged view of FIG. 1, most of the supplied liquid supply 7 is supplied to the winding body R inside the sheet material 21a and becomes an in-element flow 7a, and only a part of the supplied liquid material 21b is made of the porous material 21b. It is supplied to the bypass flow 7b.

It should be noted that, on the outermost circumference of the winding body R, there is a region where the supply side flow path material 2 is located and a region where the separation membrane 1 of the membrane leaf L is located. The lower enlarged view shows the latter state.

In the present invention, the exterior flow path material 21 (sheet material 21a in the present embodiment) covers the outer periphery of the winding body R to block the inflow of the supply liquid 7, and the flow formed outside the winding body R. The pressure loss of the path can be controlled independently. The pressure loss can be adjusted by, for example, the thickness of the porous material 21b, the number of layers, the pore size, the porosity, the direction of the knitting structure, the direction of the woven structure, and the like.

In this embodiment, an example in which the outer diameter with respect to the outer circumference of the exterior material is 100% with respect to the inner diameter of the pressure vessel 30, that is, an example in which there is no gap between the porous material 21b and the pressure vessel 30 is shown.

In the present invention, this gap may exist, but the outer diameter with respect to the outer circumference of the exterior material is preferably 99.0 to 100.0% with respect to the inner diameter of the pressure vessel 30, 99. .5 to 100.0% is more preferable, and 100.0% is even more preferable. By setting the outer diameter within such a range, the gap between the sheet material covering the outer circumference of the winding body and the inner surface of the pressure vessel becomes smaller, and it is possible to more effectively reduce the bypass flow and increase the effective film area. Become. For the same reason, the size of the gap between the porous material 21b and the pressure vessel 30 is preferably 0 to 1 mm, more preferably 0 to 0.5 mm, and most preferably 0 mm.

In the present invention, as described above, the volume of the winding body R inside the pressure vessel 30 can be increased, and more separation membrane 1 (flat membrane) can be accommodated. That is, the membrane area per element increases, and the permeation flow rate can be increased. The outer diameter of the winding body R can be improved by about 2%, and the axial length can be improved by about 2% by omitting the ATD on the upstream side. Therefore, the film area and the permeation flow rate per element can be improved. It is possible to improve by about 6%.

The porosity of the porous material 21b is preferably 5 to 80% from the viewpoint of causing an appropriate pressure loss and suitably controlling the bypass flow and the pressure distribution. More preferably, it is 10 to 50%.

The thickness of the porous material 21b (total thickness in the case of a multilayer structure) is preferably 0.2 to 2 mm, preferably 0.5 to 2 mm, from the viewpoint of causing an appropriate pressure loss and appropriately controlling the bypass flow and the pressure distribution. 1.2 mm is more preferable.

As the porous material 21b, those that can be used as the supply-side flow path material 2 or the transmission-side flow path material 3 described later, or similar materials, non-woven fabrics, polymer porous membranes, cloths, and the like can be used. , A material that can be used as the permeation side flow path material 3 is preferable from the viewpoint of pressure loss, handleability and the like.

As the specific porous material 21b, weft knitting materials such as knitting and pearl knitting, warp knitting materials such as tricot, and woven materials such as plain weave are preferably used. When a warp knitting material such as tricot half knitting or double denby knitting, which is often used for the permeation side flow path material 3, is used, the direction in which the groove / ridge is formed is the axial direction A1 of the membrane element E. It is preferable to use it in orthogonal directions. This is because the flow resistance of the bypass flow increases and the flow rate of the supply liquid leaking due to the bypass can be reduced.

Since the porous material 21b is a relatively fine material, it is expected that turbid components and the like contained in the feed solution will accumulate during the actual filtration operation, causing clogging. When clogging occurs, the pressure distribution in the gap between the membrane element E and the pressure vessel 30 becomes a pressure distribution similar to that in the case of using the U packing, and the internal pressure acts on the inner surface of the porous material 21b. The porous material 21b does not have a function of withstanding the internal pressure, but in the present invention, the outer diameter of the wound body R in a state where the porous material 21b is wound is set to a dimension substantially matching the inner diameter of the pressure vessel 30. Therefore, even if the internal pressure acts, the outer surface of the porous material 21b comes into contact with the inner wall of the pressure vessel 30 at the stage of swelling very slightly, so that no particular problem occurs.

On the other hand, as the sheet material 21a that covers the outer periphery of the winding body R, a film, a sheet, a tape, or the like can be used. By covering the outer circumference of the winding body R with such a sheet material 21a, the outer diameter of the winding body R can be adjusted accurately, and by restraining and fixing the outer circumference of the winding body R, a series of steps can be performed. It also has the effect of being able to do it smoothly. From such a viewpoint, it is preferable to use a sheet material 21a with an adhesive, particularly an adhesive tape whose base material is made of stretched polypropylene.

The outer flow path material 21 can be formed by sequentially covering the sheet material 21a and the porous material 21b in a state where the outer periphery of the winding body R is temporarily fixed, and the outer flow path material 21 can be formed, for example, as shown in FIG. 5A. It is also possible to coat the sheet material 21a and the porous material 21b in succession with the winding of the rotating body R.

That is, the sheet material 21a is extended via the adhesive portion 21c to the tip portion of any one of the transmission side flow path materials 3 used when forming the wound body R, or the tip portion to which any one is extended. It is possible to cover the outer periphery of the winding body R with the sheet material 21a when winding the winding body R. If the sheet material 21a with an adhesive is used, coating and fixing can be performed at the same time.

At that time, in particular, the permeation side flow path material 3 extended to the side of the central tube 5 is also extended to the outer peripheral side, and the sheet material 21a is adhered to the tip portion thereof via the adhesive portion 21c. Is preferable. Since the permeation side flow path material 3 has a structure sealed together with the separation film 1 when the membrane leaf L is formed, the supply liquid 7 flows through the permeation side flow path material 3 and mixes with the permeation liquid 8. There is no such thing.

The coating with the porous material 21b can be performed independently of the coating process of the sheet material 21a, but as shown in FIG. 5B, for example, the tip of the sheet material 21a is made porous via the adhesive portion 21d. It is possible to bond the material 21b and coat the bonded portion 21d in a process continuous with the coating of the sheet material 21a. The coated porous material 21b can be fixed by adhering the overlapping portion to the sheet material 21a.

The exterior material may be composed of only the exterior flow path material 21, but may include a tape for fixing or the like. However, it is preferable not to include reinforcing fibers such as glass fibers.

(Another embodiment of the exterior material)
By extending the tip of any of the transmission side flow path materials 3 used when forming the winding body R, this extending portion is used to form a porous material 21b that covers the sheet material 21a. Can be done. For example, as shown in FIG. 5C, the permeation side flow path material 3 extended to the side of the central tube 5 is extended to the outer peripheral side by a length corresponding to the porous material 21b, and this is made porous. It can be coated as the material 21b. At that time, if the sheet material 21a is arranged in the portion of the porous material 21b, the sheet material 21a and the porous material 21b can be simultaneously coated on the outer periphery of the wound body R. Also in this case, since the permeation side flow path material 3 has a structure sealed together with the separation film 1 when the membrane leaf L is formed, the supply liquid 7 flows through the permeation side flow path material 3 and the permeation liquid 8 is formed. Does not mix with.

As shown in FIG. 5D, the sheet material 21a and the porous material 21b are laminated when winding the permeation side flow path material 3 extending on the side of the central tube 5 and the outer peripheral side. It is also possible to simultaneously cover the outer periphery of the winding body R with these.

Further, as shown in FIG. 8A, the exterior flow path material 21 can be formed of a laminate including the sheet material 21a, the porous material 21b, and the sheet material 21a. That is, the sheet material 21a may be provided on the outermost layer of the exterior flow path material 21. However, since the porous material 21b generally has a higher cushioning property, when the outer flow path material 21 is brought into close contact with the inner surface of the pressure vessel 30, the porous material 21b is provided on the outermost layer of the outer flow path material 21. Is preferable.

On the other hand, as shown in FIG. 8B, it is also possible to provide the concavo-convex sheet material 21s having irregularities on the outer and / or inner surfaces instead of the porous material 21b or in addition to the porous material 21b. Examples of the uneven shape include a groove shape, a rib shape, a dot shape, an irregular pattern, and grain processing. By providing the uneven sheet material 21s, a flow path can be formed by the unevenness of the surface. At that time, the pressure loss can be adjusted by the shape, width, height, pitch, etc. of the unevenness.

As the uneven sheet material 21s, it is preferable to use an embossed sheet. It is also possible to adjust the desired pressure loss by winding the embossed sheet in a plurality of layers. By using the embossed sheet, not only the cost is advantageous, but also the handleability and the binding force at the time of winding are suitable.

The example shown in FIG. 8C is an exterior flow path material 21 in which the concave-convex sheet material 21s and the porous material 21b are combined, and various combinations are possible in the present invention.

(Supply side flow path material)
The supply-side flow path material 2 generally has a role of securing a gap for evenly supplying the fluid to the film surface. As such a supply-side flow path material 2, for example, a net, knitting, an uneven processing sheet, or the like can be used, and a material having a maximum thickness of about 0.1 to 3 mm can be appropriately used. In such a supply-side flow path material 2, it is preferable that the pressure loss is low, and it is preferable that the material 2 produces an appropriate turbulent flow effect. Further, although the flow path material is installed on both sides of the separation membrane 1, it is common to use different flow path materials as the supply side flow path material 2 on the supply liquid side and the permeation side flow path material 3 on the permeation liquid side. Is the target. It is preferable to use a net-like flow path material having a coarse and thick mesh in the supply side flow path material 2, while using a fine woven fabric or knitted flow path material in the transmission side flow path material 3.

The supply side flow path material 2 is provided on the inner surface side of the above-mentioned double-folded composite semipermeable membrane when an RO membrane or an NF membrane is used in applications such as seawater desalination and wastewater treatment. As the structure of the flow path material 2 on the supply side, generally, a network structure in which linear objects are arranged in a grid pattern can be preferably used.

The constituent material is not particularly limited, but polyethylene, polypropylene, etc. are used. These resins may contain a bactericidal agent or an antibacterial agent. The thickness of the supply-side flow path material 2 is generally 0.2 to 2.0 mm, preferably 0.5 to 1.0 mm. If the thickness is too thick, the amount of permeation decreases with the amount of membrane that can be accommodated in the membrane element, and conversely, if it is too thin, contaminants tend to adhere, so that the permeation performance tends to deteriorate.

In particular, in the present invention, by combining with the supply side flow path material 2 having a diameter of 0.6 to 1.0 mm, contaminants are less likely to be deposited and biofouling is less likely to occur. The decrease can be suppressed.

(Central canal)
The central canal 5 may be any as long as it has an opening 5a around the tube, and any conventional one can be used. Generally, when it is used for desalination of seawater, wastewater treatment, etc., the permeated water that has passed through the separation membrane 1 invades into the central canal 5 through the hole in the wall surface and forms a permeation side flow path. The length of the central tube 5 is generally longer than the axial length of the winding body R, but a central tube 5 having a connected structure such as being divided into a plurality of parts may be used. The material constituting the central tube 5 is not particularly limited, but a thermosetting resin or a thermoplastic resin is used.

That is, the central tube 5 extends only to the downstream side of the winding body R, extends to the upstream and downstream sides of the winding body R, or extends only to the upstream side of the winding body R. Any of the cases may be used. However, when the detachable anti-telescope material 25 is provided on the downstream side of the winding body R, it is preferable that the central tube 5 extends at least on the downstream side of the winding body R.

In the example of the membrane element E shown in FIG. 1, the central canal 5 projects to the upstream side and the downstream side with substantially the same length with respect to the winding body R, but as shown in FIG. 7A, the central canal 5 protrudes. When extending only to the downstream side of the winding body R, it is more preferable because peripheral parts used in the conventional structure can be shared.

(Transmission side flow path material)
The permeation side flow path material 3 is interposed between the separation membranes 1 facing each other in the membrane leaf L as shown in FIG. 3 when the RO membrane or the NF membrane is used in applications such as seawater desalination and wastewater treatment. It is provided as follows. The permeation side flow path material is required to support the pressure applied to the membrane from the back surface of the membrane and to secure a flow path for the permeation liquid.

In the present invention, in order to secure such a function, it is preferable that the permeation side flow path material is formed by the tricot knit, and it is more preferable that the tricot knit is resin-reinforced or fused after the knit is formed. ..

Examples of the constituent yarns of the permeation side flow path material include polyesters such as polyethylene terephthalate and polyethylene naphthalate, and polyolefins such as polyethylene and polypropylene. Of these, polyethylene terephthalate is particularly preferably used from the viewpoint of processability and productivity.

When reinforcing the resin after forming the knit, there are methods such as impregnating the fiber with the resin and curing it, or coating the fiber surface with the resin and curing it. Examples of the resin used for reinforcement include melamine resin and epoxy resin.

The constituent yarn of the permeation side flow path material may be monofilament or multifilament, but a tricot knit is formed by the constituent yarn having a certain thickness. Among the tricot knits, half knits and double denby knits, which have a clear structure of linearly continuous grooves, are preferable.

The thickness of the permeation side flow path material is preferably 0.10 to 0.40 mm, more preferably 0.15 to 0.35 mm, and even more preferably 0.20 to 0.30 mm. When the thickness is 0.10 mm or more, a sufficient flow path is secured and the pressure loss of the permeated liquid can be reduced. Further, when the thickness is 0.40 mm or less, the effective membrane area of the separation membrane in the membrane element becomes large, and it becomes easy to increase the flow rate of the permeate. The constituent yarn of the permeation side flow path material is preferably 0.1 to 0.15 mm in order to form a tricot knit having the above thickness.

In the present invention, the width of the linearly continuous grooves in the tricot knitted fabric is preferably 0.05 to 0.40 mm, more preferably 0.10 to 0.28 mm. If the width of the groove is less than 0.05 mm, the pressure loss of the permeate tends to be too large, and if the width of the groove exceeds 0.40 mm, the inhibition rate due to the deformation of the composite semipermeable membrane tends to decrease. May be.

Note that the width of the linearly continuous grooves in the tricot knitted fabric refers to the average value between the widest part and the narrowest part of the adjacent loops. From the microscope photograph, the above average values can be measured for 10 pairs of loops, and the average values of the 10 loop pairs can be further averaged to obtain the width of continuous grooves.

The direction in which the permeation side flow path material is arranged in the membrane element may be any, but it is preferable that the direction of the linearly continuous groove is wound in the direction along the circumferential direction.

(Separation membrane)
As the separation membrane 1, various porous membranes can be used, but a composite semipermeable membrane having a separation functional layer on the surface of the porous support is preferable. The porous support preferably has a polymer porous layer on one side of the nonwoven fabric layer. The thickness of the separation membrane, particularly the composite semipermeable membrane, is preferably about 70 to 160 μm, more preferably 85 to 130 μm.

Such composite transpermeable membranes are called RO (reverse osmosis) membranes, NF (nanofiltration) membranes, and FO (forward osmosis) membranes depending on their filtration performance and treatment method. , Can be used for desalination treatment of brackish water, reuse treatment of wastewater, etc.

Examples of the separation functional layer include polyamide-based, cellulose-based, polyether-based, and silicon-based separation functional layers, but those having a polyamide-based separation functional layer are preferable. The polyamide-based separation functional layer is generally a homogeneous film having no visible pores and has a desired ion separation ability. The separation functional layer is not particularly limited as long as it is a polyamide-based thin film that is difficult to peel off from the polymer porous layer, but for example, a polyfunctional amine component and a polyfunctional acid halide component are interfaced on the porous support film. A polymerized polyamide-based separation functional layer is well known.

The method for forming the polyamide-based separation functional layer on the surface of the polymer porous layer is not particularly limited, and any known method can be used. For example, a method such as an interfacial polymerization method, a phase separation method, and a thin film coating method can be mentioned, but in the present invention, the interfacial polymerization method is particularly preferably used. In the interfacial polymerization method, for example, a polymer porous layer is coated with an aqueous amine component containing a polyfunctional amine component, and then an organic solution containing a polyfunctional acid halide component is brought into contact with the coated surface of the aqueous amine component to cause interfacial polymerization. A method of forming a skin layer.

The polyfunctional amine component contained in the aqueous amine solution is a polyfunctional amine having two or more reactive amino groups, and examples thereof include aromatic, aliphatic, and alicyclic polyfunctional amines. Examples of the aromatic polyfunctional amine include m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, 1,3,5-triaminobenzene, 1,2,4-triaminobenzene, and 3,5-. Examples thereof include diaminobenzoic acid, 2,4-diaminotoluene, 2,6-diaminotoluene, N, N'-dimethyl-m-phenylenediamine, 2,4-diaminoanisol, amidol, xylylenediamine and the like. Examples of the aliphatic polyfunctional amine include ethylenediamine, propylenediamine, tris (2-aminoethyl) amine, n-phenyl-ethylenediamine and the like. Examples of the alicyclic polyfunctional amine include 1,3-diaminocyclohexane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, piperazine, 2,5-dimethylpiperazine, 4-aminomethylpiperazine and the like. Be done. These polyfunctional amines may be used alone or in combination of two or more. In particular, in the present invention, when a high inhibition rate is required in the reverse osmosis membrane performance, it is preferable to use m-phenylenediamine as a main component, which can obtain a highly dense separation functional layer, and a high Lux retention in the NF membrane performance. When determining the rate, it is preferable to use piperazine as the main component.

The polyfunctional acid halide component contained in the organic solution is a polyfunctional acid halide having two or more reactive carbonyl groups, and examples thereof include aromatic, aliphatic, and alicyclic polyfunctional acid halides. Examples of the aromatic polyfunctional acid halide include trimethic acid trichloride, terephthalic acid dichloride, isophthalic acid dichloride, biphenyldicarboxylic acid dichloride, naphthalenedicarboxylic acid dichloride, benzenetrisulfonic acid trichloride, benzenedisulfonic acid dichloride, and chlorosulfonylbenzene. Examples thereof include dicarboxylic acid dichloride. Examples of the aliphatic polyfunctional acid halide include propanedicarboxylic acid dichloride, butanedicarboxylic acid dichloride, pentandicarboxylic acid dichloride, propanthricarboxylic acid trichloride, butanetricarboxylic acid trichloride, pentantricarboxylic acid trichloride, glutalyl halide, and hydrangea. Poil halide and the like can be mentioned. Examples of the alicyclic polyfunctional acid halide include cyclopropanetricarboxylic acid trichloride, cyclobutanetetracarboxylic acid tetrachloride, cyclopentanetricarboxylic acid trichloride, cyclopentanetetracarboxylic acid tetrachloride, cyclohexanetricarboxylic acid trichloride, and tetrahydro. Examples thereof include furantetracarboxylic acid tetrachloride, cyclopentane dicarboxylic acid dichloride, cyclobutane dicarboxylic acid dichloride, cyclohexanedicarboxylic acid dichloride, tetrahydrofurandicarboxylic acid dichloride and the like. These polyfunctional acid halides may be used alone or in combination of two or more. In order to obtain a skin layer with high salt blocking performance, it is preferable to use an aromatic polyfunctional acid halide. Further, it is preferable to use a trivalent or higher valent polyfunctional acid halide for at least a part of the polyfunctional acid halide component to form a crosslinked structure.

The organic solvent containing the polyfunctional acid halide is not particularly limited as long as it has low solubility in water and dissolves the polyfunctional acid halide component without deteriorating the porous support film. For example, cyclohexane. Saturated hydrocarbons such as heptane, octane and nonane, halogen-substituted hydrocarbons such as 1,1,2-trichlorotrifluoroethane and the like can be mentioned. It is preferably a saturated hydrocarbon having a boiling point of 300 ° C. or lower, more preferably 200 ° C. or lower.

Additives for the purpose of improving various performances and handleability may be added to the amine aqueous solution or the organic solution. Examples of the additive include polymers such as polyvinyl alcohol, polyvinylpyrrolidone and polyacrylic acid, polyhydric alcohols such as sorbitol and glycerin, and surfactants such as sodium dodecylbenzenesulfonate, sodium dodecylsulfate and sodium laurylsulfate. , Basic compounds such as sodium hydroxide, trisodium phosphate, and triethylamine that remove hydrogen halide generated by polymerization, acylation catalysts, and solubility parameters described in JP-A-8-224452 (cal). / Cm ³ ) ^1/2 compound and the like can be mentioned.

A coating layer composed of various polymer components may be provided on the exposed surface of the separation function layer. The polymer component is not particularly limited as long as it is a polymer that does not dissolve the separation functional layer and the porous support film and does not elute during the water treatment operation. For example, polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl cellulose, polyethylene. Glycol and saponified polyethylene-vinyl acetate copolymer and the like can be mentioned. Of these, polyvinyl alcohol is preferably used, and in particular, polyvinyl alcohol having a saponification degree of 99% or more is used, or polyvinyl alcohol having a saponification degree of 90% or more is crosslinked with the polyamide resin of the skin layer. It is preferable to have a structure that does not easily elute during water treatment. By providing such a coating layer, the charge state of the film surface is adjusted and hydrophilicity is imparted, so that the adhesion of contaminants can be suppressed, and the Lux holding effect is further achieved by the synergistic effect with the present invention. Can be further enhanced.

The non-woven fabric layer used in the present invention is not particularly limited as long as it imparts appropriate mechanical strength while maintaining the separation performance and permeation performance of the composite semipermeable membrane, and a commercially available non-woven fabric is used. be able to. As this material, for example, a material made of polyolefin, polyester, cellulose or the like is used, and a material obtained by mixing a plurality of materials can also be used. In particular, polyester is preferably used in terms of moldability. Further, a long-fiber nonwoven fabric or a short-fiber nonwoven fabric can be used as appropriate, but a long-fiber nonwoven fabric can be preferably used from the viewpoint of fine fluffing that causes pinhole defects and the uniformity of the film surface.

The polymer porous layer is not particularly limited as long as it can form the polyamide-based separation functional layer, but is usually a microporous layer having a pore size of about 0.01 to 0.4 μm. Examples of the material for forming the microporous layer include polysulfone, polyaryletherketone exemplified for polyethersulfone, polyimide, polyvinylidene fluoride, and the like. In particular, it is preferable to form a polymer porous layer using polysulfone or polyaryletherketone from the viewpoint of chemical, mechanical and thermal stability.

(Anti-telescope material)
In the present invention, as shown in FIG. 1, it is preferable to provide the anti-telescope material 25 on the downstream side of the winding body R, and it is preferable to provide the removable anti-telescope material 25.

The anti-telescope material 25 preferably has at least an outer peripheral side obstruction plate 29 arranged on the downstream side near the outer periphery of the winding body R, but as shown in FIG. 4, near the outer periphery of the winding body R. It is more preferable to provide the outer peripheral side obstruction plate 29 arranged on the downstream side and the inner peripheral side obstruction plate 27 arranged on the downstream side near the inner circumference of the winding body R. Here, the vicinity of the inner circumference of the winding body R refers to any position within the range of 0 to 30% from the inner circumference when the distance between the outer circumference and the inner circumference of the winding body R is 100%. , Near the outer circumference refers to any position within a range of 70% or more from the inner circumference.

The outer diameter of the outer peripheral side baffle plate 29 may be larger than the outer diameter of the winding body R, and is preferably 98 to 100.0% with respect to the inner diameter of the pressure vessel 30, 99 to 100.0. % Is more preferable, and 100.0% is most preferable. By setting the outer diameter of the outer peripheral side baffle plate 29, the low-concentration concentrated liquid flowing inside or outside the layer of the porous material 21b can be more effectively mixed and stirred and supplied to the next stage. Can be done.

As shown in FIG. 4, the anti-telescope material 25 of the present embodiment shows an example having an annular portion 26 and ribs 28 extending radially from the annular portion 26. The number of ribs 28 is not particularly limited, but 4 to 20 are preferable, and 8 to 16 are more preferable, from the viewpoint of ensuring sufficient flow path and strength while suppressing the telescope.

It is preferable that the anti-telescope material 25 is detachably attached to the central tube 5 extending to the downstream side of the winding body R. Therefore, the annular portion 26 has an inner peripheral surface into which the central canal 5 can be fitted. The rib 28 can prevent the winding body R from being deformed in a telescope shape by abutting the end surface on the upstream side of the rib 28 on the downstream end surface of the winding body R.

The reason why it is preferable to provide the outer peripheral side obstruction plate 29 and the inner peripheral side obstruction plate 27 on the anti-telescope material 25 will be described in detail.

There is a concentration distribution in the concentrate flowing out of the membrane element E. There are two reasons for causing non-uniformity of concentration, one is that in each membrane leaf L, the closer to the central canal 5 the larger the Lux, and the closer to the leaf end the smaller the Flux, and the feed solution 7 is the membrane element. As the supply-side flow path in E flows in the axial direction A1, the closer to the central tube 5, the more concentrated the supply liquid 7 becomes, and the higher the concentration becomes. The other is that the portion where the membrane permeation does not occur is not concentrated, so that the concentration remains low as compared with the portion where the concentration is increased by the membrane permeation. The non-penetrating portion is a portion of the protective tape to be attached to the inside of the crease to protect the crease of the separation film 1 and a portion to which the adhesive of the leaf end portion is applied.

These concentration distributions exist in the concentrated liquid flowing out from the membrane element E, but in particular, the low-concentration portion corresponding to the latter has room for consideration in discussing the filtration efficiency of the entire membrane module. .. The latter corresponds to the crease portion of the membrane and the portion corresponding to the leaf end, and in terms of the exit cross section of the membrane element E, it is a portion close to the central canal 5 and a portion close to the opposite outer periphery. The concentration of the concentrate 9 flowing out from these parts is lower than that in the other parts, but if it flows into the membrane element E in the next stage in the same distribution state, it may flow on the center tape and the leaf end as in the previous stage. Is high. A low concentration means that the osmotic pressure is low, and it is not efficient to flow a portion that is not filtered by the membrane even though the supply liquid 7 is expected to have a high Lux if the membrane surface is flushed.

As a countermeasure, a baffle plate structure is provided on the anti-telescope material 25 in the two places where the concentration is low so that the supply liquid 7 can detour and flow. The low-concentration part and the high-concentration part are agitated and mixed by the vortex generated in the wake when bypassing the baffle plate, and the filtration performance of the membrane module as a whole can be improved.

Since the supply liquid 7 flowing through the layer of the porous material 21b is also not membrane-filtered, the concentration is maintained at a low level. This can also be agitated and mixed with the high-concentration portion by bypassing the flow with the baffle plate structure on the outer peripheral side.

(Another Embodiment of Anti-Telescope Material)
In the previous embodiment, an example having the annular portion 26 and the rib 28 extending radially from the annular portion 26 has been shown, but as shown in FIG. 6A, the inner peripheral side of the rib 28 abuts on the central canal 5 and the like. It is possible to omit 26.

Further, as shown in FIG. 6B, the outer peripheral side obstruction plate 29 arranged on the downstream side near the outer peripheral side of the winding body R and the inner peripheral side obstruction plate arranged on the downstream side near the inner circumference of the winding body R. 27 may be formed by a continuous plate-shaped portion, and a plurality of openings may be provided in the plate-shaped portion.

Further, as shown in FIG. 6C, the inner peripheral side obstruction plate 27 is omitted, or a sealing material (for example, an O-ring) is provided on the outer peripheral side of the outer peripheral side obstruction plate 29, and the anti-telescope material 25 is provided on the inner surface of the pressure vessel 30. The outer periphery of the surface may be brought into close contact with the surface.

The interconnector 35 may be integrated with the anti-telescope material 25 so that the interconnector 35 has a function as the anti-telescope material 25. For example, as shown in FIG. 7B, instead of providing the annular portion 26, an inner peripheral side obstruction plate 27 is provided around the interconnector 35, the inner peripheral end of the rib 28 is arranged near the outer periphery of the central tube 5, and the rib 28 is provided. The structure may be such that the outer peripheral side baffle plate 29 is provided via the above.

(Another Embodiment of Spiral Membrane Elements)
In the above description, the most preferable embodiment of the present invention has been described. However, the present invention is not limited to the embodiment, and various modifications can be made within substantially the same range as the technical idea described in the claims of the present invention.

That is, in the above embodiment, as shown in FIGS. 2A to 2C, the permeation side flow path material 3 is superposed on the separation membrane 1 folded in half so as to sandwich the supply side flow path material 2. The example of applying the

adhesives

4 and 6 has been described. However, in the present invention, it is also possible to superimpose the separation membrane 1 folded in half on the permeation side flow path material 3 and apply the

adhesives

4 and 6 on it. Further, instead of the separation membrane 1 folded in half, two separation membranes 1 may be used to sandwich the supply side flow path material 2 and a sealing portion may be provided on the winding start side as well. Further, the continuous separation membrane 1 may be used to eliminate the need for the outer peripheral side sealing portion 12.

(Spiral type membrane module)
As shown in FIG. 1, the spiral type membrane module of the present invention includes the spiral type membrane element E as described above and the pressure vessel 30 for accommodating the spiral type membrane element E, and has an outer diameter based on the outer periphery of the exterior material. It is characterized in that it is 99 to 100% with respect to the inner diameter of the pressure vessel 30. As the pressure vessel 30, any of those conventionally used for accommodating the membrane element E can be used.

In the illustrated example, the pressure vessel 30 includes an outer cylinder member 31, a downstream end plate member 32, and an upstream end plate member 34, and the holding ring 33 allows the

end plate members

32, 34 to be formed. It is liquidtightly held by the outer cylinder member 31.

Further, the membrane elements E are connected to each other by an interconnector 35, and the upstream side of the central tube 5 of the membrane element E on the most upstream side is closed by a cap 37. The downstream side of the central tube 5 of the membrane element E on the most downstream side is connected to the opening of the end plate member 32 on the downstream side by an adapter 36, so that the permeate 8 can be discharged. The downstream end plate member 32 is further provided with an opening capable of discharging the concentrated liquid 9, and the upstream end plate member 34 is provided with an opening capable of supplying the supply liquid 7.

In the illustrated example, the anti-telescope material 25 shown in FIG. 4 is provided, and the outer peripheral side obstruction plate 29 arranged on the downstream side near the outer peripheral surface of the winding body R has the outer peripheral surface on the inner surface of the pressure vessel 30. It is in contact with each other. As a result, the amount of the concentrated liquid 9 flowing through the gap between the outer peripheral side obstruction plate 29 and the inner surface of the pressure vessel 30 can be reduced as much as possible, and the stirring / mixing effect can be further enhanced.

The material, structure, manufacturing method, anti-telescope material 25, etc. of each member of the spiral type film element E are as described above.

According to the present invention, it is possible to efficiently dispose of the used membrane element. Since no glass fiber is required for the exterior of the film element, no glass remains in the incinerated ash even when incinerated, which facilitates the treatment of the incinerated ash.

When the used film element is used as a material for thermal recycling, it can be processed into RPF (refuse paper and plastic fuel), and the RPF manufactured by using the waste element can be suitably used in a paper mill. .. When manufacturing an RPF, there is less mechanical wear during crushing and less damage to the crusher.

If the anti-telescope material is removable, it can be used repeatedly, and the number of uses can be reduced because it is installed only on the downstream side. Since the U packing can be omitted, the cost of the U packing can be reduced. Since the outer diameter and the axial length of the winding body can be expanded, the membrane area per membrane element can be increased, and the amount of the treatment liquid can be improved.

1: Separation film 2: Supply side flow path material 3: Permeation side flow path material 5: Central tube 7: Supply liquid 8: Permeation liquid 9: Concentrate liquid 21: Exterior flow path material 21a: Sheet material 21b: Porous material 21s : Concavo-convex sheet material 25: Anti-telescope material 27: Inner peripheral side obstruction plate 29: Outer peripheral side obstruction plate 30: Pressure vessel A1: Axial center direction E: Spiral type film element R: Winding body

Claims

A spiral membrane element comprising a perforated central tube, a winding body wound around the central tube and containing a separation membrane, and an exterior material provided on the outer periphery of the winding body.
The exterior material is a spiral type membrane element including an exterior flow path material that covers the outer periphery of the winding body to block the inflow of supply liquid and forms a flow path outside the winding body.
The spiral type membrane element according to claim 1, wherein the exterior flow path material includes a sheet material that covers the outer periphery of the winding body and a porous material that covers the sheet material.
The spiral type membrane element according to claim 1 or 2, wherein when used in a pressure vessel, the outer diameter with respect to the outer circumference of the exterior material is 99 to 100% with respect to the inner diameter of the pressure vessel. ..
The spiral type membrane element according to any one of claims 1 to 3, wherein a removable anti-telescope material is provided on the downstream side of the winding body.
The anti-telescope material is provided with an outer peripheral side obstruction plate arranged on the downstream side near the outer periphery of the winding body and an inner peripheral side obstruction plate arranged on the downstream side near the inner circumference of the winding body. The spiral type membrane element according to claim 4.
The spiral type membrane element according to claim 4 or 5, wherein the anti-telescope material is attached to the central tube extending to the downstream side of the winding body.
The spiral type membrane element according to any one of claims 1 to 6 and a pressure vessel for accommodating the spiral type membrane element are included.
A spiral type membrane module having an outer diameter based on the outer circumference of the exterior material, which is 99 to 100% of the inner diameter of the pressure vessel.