JP2006218345A - Spiral type membrane element and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spiral type membrane element capable of effectively preventing reduction of adhesion force at a sealing part while maintaining an effective film area without spreading a coating width of an adhesive, and its production method. <P>SOLUTION: The spiral type membrane element is provided with a cylindrical winding body R in which a separation membrane 1, a feeding side flowing passage material 2 and a permeation side flowing passage material 3 are wound on a periphery of a central pipe 5 with an aperture in a spiral shape in the state that they are superposed, and in the element, the sealing part for preventing mixing of a feeding side fluid and a permeation side fluid is provided. The separation membranes 1 opposed to each other through the permeation side flowing passage material 3 at least have both end sealing parts 11 formed at both axial sides by the adhesive and the whole or a part of the permeation side flowing passage materials 3 positioned at both end sealing parts is only cut/removed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a component in which a separation membrane, a supply-side channel material, and a permeate-side channel material are spirally wound around a perforated central tube in a laminated state, and are suspended and dissolved in a liquid The present invention relates to a spiral type membrane element that separates and the like, and a method for manufacturing the same. The present invention relates to a technique that can effectively prevent a decrease in adhesive force particularly when a sealing portion for preventing mixing of a supply-side fluid and a permeation-side fluid is formed with an adhesive.

  Conventionally, as fluid separation elements used for reverse osmosis filtration, microfiltration, etc., for example, a supply-side flow path material that guides a supply-side fluid (raw water) to the separation membrane surface, a separation membrane that separates the supply-side fluid, and a separation membrane A spiral-type membrane element in which a unit comprising a permeate-side channel material that guides a permeate-side fluid (permeate) that has permeated and separated from a supply-side fluid to a central tube (collection tube) is wound around a perforated central tube Are known.

  As shown in FIGS. 3 (a) to 3 (b), such a spiral membrane element generally has a structure in which a supply-side flow path material 2 is disposed between two folded separation membranes 1, and a permeation side. Permeate side flow path material positioned on the periphery (3 sides) of the separation membrane in order to stack the flow path material 3 and form a sealing portion that prevents mixing of the supply side fluid and permeate side fluid The separation membrane unit U is manufactured by applying to 3, and one or more of the units U are wound around the central tube 5 in a spiral shape, and the periphery of the separation membrane is further sealed. At that time, from the viewpoint of easily aligning the edges in the manufacturing process, as shown in FIG. 3A, the axial width of the permeate-side flow path member 3 and the axial width of the separation membrane 1 are substantially equal. The end side of the permeation side channel material 3 was cut.

  According to the above manufacturing method, as shown in FIG. 4, both ends of the separation membrane 1 facing each other through the permeate-side flow path member 3 are sealed by the both-end sealing portions 11. The end portion on the outer peripheral side of the separation membrane 1 facing each other is sealed by the outer peripheral side sealing portion 12 along the axial direction. This example is a case where there are a plurality of membrane leaves (sealed envelope-like membranes), but there are cases where there is a single membrane leaf (see, for example, Patent Document 1).

  The both-end sealing portion 11 and the outer peripheral side sealing portion 12 as described above are bonded using adhesives 4 and 6. However, in the conventional structure, the separation membrane 1 facing the permeation-side flow path material 3. Therefore, the adhesives 4 and 6 are impregnated into the two separation membranes 1 and the permeation side flow path material 3 to bond them together.

  However, in general, in order to increase the effective membrane area, it is effective to narrow the adhesive width of the adhesive, and in this method, the amount of adhesive applied is reduced, so that the adhesive to the separation membrane is reduced. A portion where the impregnation is insufficient is likely to occur. If it does so, the adhesive force of an adhesion part will decline by this and the problem which an adhesion part peels depending on the case has arisen.

  As a measure for preventing separation of the bonded portion by the adhesive, a method is known in which a primer is applied in advance to the surfaces of the separation membranes to be bonded to each other, dried, and then the adhesive is applied to adhere the separation membranes together. (For example, refer to Patent Documents 1 and 3). However, this method requires primer application and drying steps, and at present, automation is not realized and productivity is very poor.

In addition, a technique for sealing both end sealing portions of a spiral membrane element using a thermal adhesive tape is also known (see, for example, Patent Document 2). However, this method has a problem that the adhesive strength of the adhesive portion is lower than that when an adhesive is used.
Japanese Patent Laid-Open No. 10-341 JP 2003-275547 A JP 2004-74023 A

  Accordingly, an object of the present invention is to provide a spiral-type membrane element capable of effectively preventing a decrease in adhesive strength in a sealing portion while maintaining an effective membrane area without widening the application width of the adhesive, and its It is to provide a manufacturing method.

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

  A spiral membrane element of the present invention includes a cylindrical wound body in which a separation membrane, a supply-side channel material, and a permeate-side channel material are wound in a spiral shape around a perforated central tube in a stacked state. In addition, in the spiral-type membrane element provided with a sealing portion for preventing mixing of the supply side fluid and the permeate side fluid, the separation membranes facing each other through the permeate side channel material are at least on both sides in the axial direction. While having the both-ends sealing part formed with the adhesive agent, the permeation | transmission side flow-path material located in the both-ends sealing part is cut out all or only one part, It is characterized by the above-mentioned.

    According to the spiral membrane element of the present invention, the permeation-side channel material located at the both-end sealing portion is cut out in whole or in part, so that the opposing separation membrane is not interposed through the permeation-side channel material. It will be directly bonded by an adhesive. For this reason, the impregnation defect to the permeation | transmission side channel material of an adhesive agent or bubble residue does not arise, the impregnation property to the separation membrane of an adhesive agent improves, and it can adhere | attach a sealing part more reliably. As a result, it is possible to effectively prevent a minute leak in the sealing portion while maintaining an effective film area.

  In the above, the permeate-side flow path member has an inner peripheral side surplus portion that extends further to the inner peripheral side than the inner peripheral side end of the adjacent separation membrane and is wound around the central tube, and the inner peripheral side surplus Preferably, the axial width of the portion is substantially equal to the width of the separation membrane, and the inner peripheral side end of the both-end sealing portion is sealed with an adhesive impregnated in the inner peripheral excess portion.

  In this way, the inner peripheral side surplus part is impregnated with the adhesive by leaving the inner peripheral side surplus part substantially equal to the width of the separation membrane, rather than narrowing the entire axial width of the permeate side channel material. Thereby, the inner peripheral side end portion of the both end sealing portion can be easily and reliably sealed.

  Further, the separation membrane facing through the permeate-side flow path member further has an outer peripheral side sealing portion formed in the axial direction by an adhesive at an outer peripheral side end portion, and is positioned in the outer peripheral side sealing portion. It is preferable that all or part of the permeate side channel material is cut off. In this case, even at the outer peripheral side sealing portion, the opposing separation membrane can be directly bonded with an adhesive without passing through the permeation-side channel material, and the impregnation property of the adhesive into the separation membrane is improved and sealing is more reliably performed. Since a stop part can be adhere | attached, the adhesive force in a both-ends sealing part can be improved, without extending the application | coating width | variety of an adhesive agent. As a result, it is possible to effectively prevent a decrease in adhesive strength at the sealing portion while maintaining an effective film area.

  On the other hand, the manufacturing method of the spiral membrane element of the present invention is a cylindrical shape in which a separation membrane, a supply-side channel material, and a permeate-side channel material are spirally wound around a perforated central tube in a laminated state. In the method of manufacturing a spiral element comprising a step of forming a wound body and a step of forming a sealing portion for preventing mixing of the supply-side fluid and the permeation-side fluid, With the permeation-side flow channel material in which all or a part of the region located in the sealing portion is removed being interposed, both side ends or outer peripheral side ends of the opposing separation membrane are sealed with an adhesive. Including a step of stopping.

  According to the manufacturing method of the present invention, the opposing separation membrane can be directly bonded with an adhesive without passing through the permeate-side channel material at both side ends or outer peripheral side ends of the separation membrane. This improves the impregnation of the sealing portion, and allows the sealing portion to be bonded more reliably. For this reason, the adhesive force in a both-ends sealing part can be improved, without extending the application | coating width of an adhesive agent. As a result, it is possible to effectively prevent a decrease in adhesive strength at the sealing portion while maintaining an effective film area.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a process diagram showing an example of a spiral membrane element manufacturing method of the present invention. FIG. 2 is a partially broken perspective view showing an example of the spiral membrane element of the present invention.

  The spiral type membrane element of the present invention is different from the conventional one only in the structure of the sealing portion joined using an adhesive, and the other configurations apply any of the configurations of the conventional spiral type membrane element described above. can do.

  As shown in FIGS. 1 and 2, the spiral membrane element of the present invention has a separation membrane 1, a supply-side channel material 2, and a permeate-side channel material 3 in a laminated state around a perforated central tube 5. A cylindrical winding body R wound in a spiral shape is provided, and a sealing portion for preventing mixing of the supply side fluid and the permeation side fluid is provided. The sealing portion includes a both-end sealing portion 11 and an outer peripheral side sealing portion 12.

  As shown in FIG. 2, both ends of the separation membrane 1 facing each other through the permeate-side flow path member 3 are sealed by both-end sealing portions 11 and between a plurality of both-end sealing portions 11 arranged in a spiral shape. The supply-side flow path material 2 is interposed between them. Moreover, the outer peripheral side edge part of the separation membrane 1 which opposes through the permeation | transmission side flow path material 3 is sealed by the outer peripheral side sealing part 12 along the axial direction.

  The cylindrical wound body R is formed by spirally winding the separation membrane 1, the supply-side channel material 2, and the permeate-side channel material 3 around the perforated center tube 5. It can be manufactured by a step of forming the rotating body R and a step of forming the sealing portions 11 and 12 for preventing the supply side fluid and the permeation side fluid from being mixed.

  Specifically, for example, it can be manufactured by the embodiment shown in FIG. FIG. 1A is an assembled perspective view of a separation membrane unit, and FIG. 1B is a front view showing a state before the separation membrane units are stacked and wound.

  First, as shown in FIG. 1 (a), the supply side flow path material 3 and the permeate side flow path material 3 are stacked while the separation membrane 1 is folded in half, and the supply side fluid and the permeation side fluid are stacked. A unit is prepared in which adhesives 4 and 6 for forming a sealing portion that prevents the mixing of these are applied to both end portions in the axial direction and winding end portions of the permeate-side flow path member 3. At this time, a protective tape may be attached to the fold portion of the separation membrane 1.

  As the separation membrane 1, a reverse osmosis membrane, an ultrafiltration membrane, a microfiltration membrane, a gas separation membrane, a degassing membrane, or the like can be used. For the supply-side channel material 2, a net-like material, a mesh-like material, a grooved sheet, a corrugated sheet, or the like can be used. For the permeate side channel material 3, a net-like material, a mesh-like material, a grooved sheet, a corrugated sheet or the like can be used. The perforated center tube 5 only needs to have an opening around the tube, and any conventional tube can be used.

  As the adhesives 4 and 6, any conventionally known adhesives such as urethane adhesives, epoxy adhesives, hot melt adhesives and the like can be used.

  In the spiral membrane element of the present invention, all or part of the permeate-side channel material 3 located at the both-end sealing portion 11 is cut off. In the present embodiment, as shown in FIG. 2, the permeation-side flow path material 3 located at the both-end sealing portion 11 is partially excised (partially excised), and the outer peripheral-side sealing portion 12 The example which has the excision part 3b by which the permeation | transmission side flow-path material 3 located in part is excised is shown. As described above, since a part of the permeation side flow path member 3 is interposed in the sealing portions 11 and 12, it is possible to prevent deformation of the vicinity of the seal portion due to the displacement of the permeation side flow path member 3, and the separation membrane 1 durability can be improved.

  Such a structure, as shown in FIG. 1 (a), uses a permeation-side flow path material 3 in which all or a part of the region located in the both-end sealing part 11 or the outer peripheral sealing part 12 is cut off. In this state, it can be obtained by sealing the opposite side ends or the outer peripheral side ends of the opposing separation membrane 1 with an adhesive.

  In the present embodiment, as shown in FIGS. 1A and 2, the permeation-side flow path member 3 extends further to the inner peripheral side than the inner peripheral end 1 a of the adjacent separation membrane 1 and extends to the central tube 5. And the inner peripheral side surplus part 3c has an axial width substantially equal to the width of the separation membrane 1, and both ends are bonded by an adhesive impregnated in the inner peripheral side surplus part 3c. The example by which the inner peripheral side edge part (inner peripheral side end sealing part 13) of the sealing part 11 is sealed is shown.

  In this invention, since adhesiveness increases by forming the cut part 3a and the cut part 3b, the axial direction width | variety of the both ends sealing part 11 can be 10-20 mm, and the outer peripheral side sealing part 12 of The circumferential width can be 15 to 25 mm.

  In addition, the circumferential length of the inner peripheral side surplus part 3c is the separation membrane in which the sealed state of the inner peripheral side end sealing part 13 is wound around the central tube 5 without a gap and is laminated on the central tube 5 From the viewpoint of winding the unit vertically, it is preferable that the length is approximately the same as that of the central tube 5. Moreover, it is preferable that the axial width of the inner peripheral side surplus portion 3 c is substantially equal to the axial width of the separation membrane 1.

  It is preferable to roughen the both-end sealing part 11 of the cylindrical wound body and, if necessary, the bonding surface of the separation membrane 1 located on the outer peripheral side sealing part 12. Such a structure can be formed by including a step of roughening the adhesion surface of the separation membrane 1 located in the sealing portion prior to the sealing step.

  In the present invention, as a method of roughening the adhesion surface of the separation membrane 1, a method of mechanically scraping the surface of the separation membrane, a method of forming micropores on the surface of the separation membrane with a fine needle, or roughening by chemical etching is used. Examples of the surface forming method include formation of irregularities by laser processing, and a method of melting and deforming the surface of the separation membrane by a heating press or the like. Of these, it is preferable to roughen the separation membrane surface by melting from the viewpoint of low dust generation.

  Next, as shown in FIG. 1B, a plurality of the separation membrane units U are stacked and wound around the perforated central tube 5 in a spiral shape, and then the adhesive is cured by heat or the like. Thus, the cylindrical wound body R is obtained. At that time, sealing around the central tube 5 may be performed simultaneously. The cylindrical wound body R is trimmed at both ends as necessary in order to adjust the length in the axial direction.

  The number when the separation membrane unit U is stacked is determined according to the required permeation flow rate and may be one or more layers, but about 100 layers is the upper limit in consideration of operability. The larger the number of separation membrane units U stacked, the fewer the number of turns of each separation membrane unit U.

  The spiral membrane element of the present invention is usually constrained by an exterior material and does not expand in diameter, but the exterior material may be wound with one or more sheets on the surface of a cylindrical wound body. it can. As the exterior material, polyester, polypropylene, polyethylene, polyvinyl chloride, glass fiber cloth, or the like can be used.

  The spiral membrane element of the present invention can be further provided with a perforated end member for preventing deformation (telescope or the like), a sealing material, a reinforcing material, and the like as necessary.

[Other Embodiments]
(1) In the above-described embodiment, an example in which the permeation-side flow path material has an inner peripheral side surplus portion that extends further to the inner peripheral side than the inner peripheral side end of the adjacent separation membrane and is wound around the central tube. Although shown, it is also possible to use a permeate-side channel material that does not have an inner peripheral side surplus portion. In that case, it is preferable to employ a method of applying an adhesive in advance around the central tube, a method of winding a sealing material, or the like from the viewpoint of more reliably sealing the inner peripheral side end of the both-end sealing portion. .

  (2) In the above-described embodiment, an example in which a part of the permeation-side channel material is interposed in the sealing part by excising only a part of the permeation-side channel material located in the sealing part, The permeation-side channel material may not be interposed at all in the sealing portion by excising the entire permeation-side channel material located in the sealing portion. In that case, it is possible to make the width of the cut portion larger than the width of the sealing portion, but it is preferable that the distance between the end side of the permeation-side channel material and the sealing portion is smaller.

  (3) In the above-described embodiment, an example in which the permeation-side channel material positioned in the sealing portion is cut with a constant width is shown. However, the shape of the cutting portion may be any, for example, a circular shape or a square shape. A plurality of excision parts may be provided. This also makes it possible to directly bond the opposing separation membrane with an adhesive at the excision portion, improve the impregnation property of the adhesive into the separation membrane, and more reliably adhere the sealing portion.

  (4) In the above-described embodiment, when the separation membrane unit is manufactured, the separation membrane is folded in half and the supply-side flow path material is sandwiched. However, the separation membrane unit is folded back alternately using a continuous separation membrane. It is also possible to sandwich the supply-side channel material and the permeation-side channel material. In that case, it suffices to provide a cut-out portion of the permeate-side channel material only for the both-end sealed portions.

  (5) In the above-described embodiment, as shown in FIG. 1, the permeation-side channel material 3 is overlapped on the separation membrane 1 folded in half so as to sandwich the supply-side channel material 2, and the adhesive 4 In the present invention, it is also possible to apply the adhesives 4 and 6 on the separation membrane 1 that is folded in two on the permeate-side channel material 3.

  (6) In the above-described embodiment, as shown in FIG. 1, an example in which a spiral membrane element including a plurality of membrane leaves is manufactured using a plurality of separation membrane units U has been described. A spiral membrane element having one membrane leaf may be manufactured using a set of separation membrane units U.

  Examples and the like specifically showing the configuration and effects of the present invention will be described below.

Example According to the process shown in FIG. 1, a reverse osmosis membrane (skin layer: polyamide system, support: porous body of polysulfone, thickness 50 μm), a supply side channel material made of polypropylene (PP), and a polyester (PET) The permeate channel material was laminated (for 21 leaves) and wound around the perforated central tube in a spiral shape to produce an 8-inch spiral membrane element. At that time, the permeation-side flow path material is cut off at a width of 45 mm with respect to the width of 20 mm at both ends of the sealing portion, the permeation-side flow path material is cut off at a width of 30 mm with respect to the width of 25 mm of the outer peripheral side sealing portion, The permeation-side channel material was provided with an inner peripheral side surplus portion having a length of 40 mm, and the periphery of the separation tube and the periphery of the central tube were sealed using urethane resin as an adhesive. After the adhesive was cured, the dyeing was confirmed. For staining confirmation, a stock solution mixed with direct blue (Mw = 993) was filtered under normal operating conditions. The minute leak portion is dyed blue. As a result, there were no minute leaks in all 20 manufactured.

In the comparative example, an 8-inch spiral membrane element was manufactured in the same manner except that the permeation-side channel material was not cut off at the sealed portion, and dyeing was confirmed. As a result, 1 out of 20 produced was a minute leak.

Process drawing which shows an example of the manufacturing method of the spiral type membrane element of this invention The partially broken perspective view which shows an example of the spiral type membrane element of this invention Process drawing showing an example of a conventional method for manufacturing a spiral membrane element Partially broken perspective view showing an example of a conventional spiral membrane element

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Separation membrane 1a Inner peripheral side end of separation membrane 2 Supply side flow path material 3 Permeation side flow path material 3a, 3b Cutout part 3c Inner peripheral side surplus part 4 Adhesive 5 Central pipe 6 Adhesive 11 Both ends sealing part 12 Outer circumference Side sealing part 13 Inner peripheral side end sealing part R Cylindrical winding body U Separation membrane unit

Claims (4)

A separation membrane, a supply-side flow path material, and a permeate-side flow path material are provided with a cylindrical wound body spirally wound around a perforated central tube in a laminated state, and a supply-side fluid and a permeation-side fluid In the spiral membrane element provided with a sealing portion for preventing the mixing of
The separation membrane facing through the permeate-side channel material has both end sealing portions formed of an adhesive on both sides in the axial direction, and all the permeation-side channel materials located at the both end sealed portions are Alternatively, a spiral membrane element characterized in that only a part is cut off.   The permeate-side channel material has an inner peripheral side surplus portion that extends further to the inner peripheral side than the inner peripheral side end of the adjacent separation membrane and is wound around the central tube, and the inner peripheral side surplus portion is a shaft. The spiral-type membrane element according to claim 1, wherein the width in the direction is substantially equal to the width of the separation membrane, and the inner peripheral side end of the both-end sealing portion is sealed with an adhesive impregnated in the inner peripheral surplus portion. .   The separation membrane facing through the permeate side channel material further has an outer peripheral side sealing portion formed in the axial direction by an adhesive at the outer peripheral side end portion, and the permeation side located in the outer peripheral side sealing portion. The spiral membrane element according to claim 1 or 2, wherein all or part of the channel material is cut off. A process of forming a cylindrical wound body by winding a separation membrane, a supply-side channel material, and a permeate-side channel material in a spiral shape around a perforated central tube, and a supply-side fluid and a permeation A method of manufacturing a spiral element comprising a step of forming a sealing portion for preventing side fluid mixing,
The sealing portion forming step includes both end portions in the axial direction of the facing separation membrane in a state where a permeation-side flow passage material in which all or part of the region located in the sealing portion is cut is interposed. Or the manufacturing method of the spiral-type membrane element characterized by including the process of sealing an outer peripheral side edge part with an adhesive agent.

Images