JP2004322016A - Spiral type film element and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spiral type film element capable of increasing an adhesion strength among a separation film, a supply side flowing passage material and a penetration side flowing passage material in a rolled body, thereby preventing a telescope phenomenon as well as internal cockles. <P>SOLUTION: The separation film, the supply side flowing passage material and the penetration side flowing passage material are spirally rolled around an central pipe having a central through hole, under a condition in which both ends in the axial direction of the penetration side flowing passage are at least sealed up with an exterior material attached to the surface of the rolled body, thereby forming the spiral type film element. The exterior material is formed by one or more sheets 2 generally symmetrically rolled in such a manner that they are spreading from a position near the center in the axial direction of the rolled body towards both ends thereof. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

TECHNICAL FIELD OF THE INVENTION
In the present invention, the separation membrane, the supply-side flow path material, and the permeation-side flow path material are spirally wound around a perforated center tube with at least both ends in the axial direction of the permeation-side flow path sealed. The present invention relates to a spiral-type membrane element provided with an exterior material on the surface of a wound body thereof, and a method for producing the spiral-type membrane element.
[Prior art]
As a spiral membrane element used for reverse osmosis filtration, ultrafiltration, microfiltration, gas separation, degassing, etc., for example, a supply-side channel material that guides the supply fluid to the separation membrane surface, a separation membrane that separates the supply fluid, separation A spiral-type membrane element is known in which a unit made of a permeate-side flow path material that permeates a membrane and separates a supply fluid from a supply fluid to a central pipe is wound around the central pipe.
Such a spiral type membrane element has a structure in which the supply-side flow path material is disposed while the separation membrane is folded in two, and the permeation-side flow path material is alternately stacked, and is bonded to prevent mixing of the supply fluid and the permeation fluid. One or more of the units in which the agent is applied to the periphery of the separation membrane are wound in a cylindrical shape around the central tube, and then a sheet holding the shape of the wound body is wound around the outer periphery of the wound body ( For example, see Patent Document 1).
Conventionally, in the production of the membrane element, as a method of winding a sheet around a wound body,
1) A method of winding a sheet 11 having substantially the same width as the spiral membrane element axial direction length as shown in FIG. 6, or 2) A strip-shaped narrow sheet 12 as shown in FIG. The method of spirally winding was common.
[Patent Document 1]
Japanese Patent No. 3035373 (page 2, FIG. 2)
[Problems to be solved by the invention]
However, in the former method 1), only the both ends in the axial direction of the wound body are thick due to the thickness of the adhesive applied to the periphery of the separation membrane, and when a sheet having the same width as the axial length is wound around the outer periphery, The force is concentrated only on the thicker ends in the axial direction, and no force is applied on the central portion in the axial direction. For this reason, in the central portion in the axial direction, the adhesion between the separation membrane, the supply-side flow path material, and the permeation-side flow path material is low, and the separation membrane and / or the supply-side flow path material are not impregnated with the adhesive, and have a sealing function. Since the supply-side flow path material is floating from the separation membrane even if it cannot be expressed or can be sealed, the stirring effect near the separation membrane, which is a function of the supply-side flow path material, is reduced, and in the vicinity of the separation membrane, Since the concentration polarization becomes large, it becomes a factor of deteriorating the performance of the spiral membrane element. In addition, if the overall wrapping force is increased to apply a force to the central portion in the axial direction, wrinkles are generated in the membrane sheet and the like, and in this case, the performance of the spiral membrane element is also reduced.
In the latter method 2), since the winding is started from one end of the wound body, the force for tightening the surface at the winding start side is increased, and the torsion force tends to cause a telescopic phenomenon. For this reason, it is necessary to wind the sheet so that the torsional force is equal to or less than a certain value. However, in this case, the tightening force becomes insufficient even in the central portion in the axial direction, and as in 1), the performance of the spiral membrane element is reduced. It becomes.
Therefore, an object of the present invention is to increase the adhesion between the separation membrane, the supply-side flow path material, and the permeation-side flow path material inside the wound body, and to prevent a telescopic phenomenon and a wrinkle inside the spiral membrane. An object of the present invention is to provide an element and a method of manufacturing the element.
[Means for Solving the Problems]
The above object can be achieved by the present invention as described below.
That is, the spiral-type membrane element of the present invention has a perforated central pipe in which the separation membrane, the supply-side flow path material, and the permeation-side flow path material seal at least both axial ends of the permeation-side flow path. In a spiral type membrane element wound spirally and provided with an exterior material on the surface of the wound body, the exterior material is wound substantially symmetrically so as to spread from near the axial center of the wound body to both end sides. It is characterized in that it is a turned single or plural sheets.
According to the spiral membrane element of the present invention, since the sheet as the exterior material is wound substantially symmetrically so as to spread from the vicinity of the center in the axial direction of the winding body to both end sides, both ends in the axial direction of the permeation-side flow path Even if only the two ends in the axial direction of the wound body are thickened due to the thickness of the sealing part, the force is first applied to the central part in the axial direction, so that the separation membrane, the supply-side flow path material, and the permeation-side flow path material Can be enhanced. Further, since the sheet is sequentially wound outward, the adhesiveness is improved at all portions, and the generation of wrinkles can be suppressed because excessive force is not applied to the sheet. Further, since the sheet is wound symmetrically from the center, a force is applied symmetrically in the axial direction, and the telescope phenomenon does not occur. As a result, the performance of the spiral membrane element can be prevented from deteriorating.
In the above, the exterior material is an even number of sheets wound substantially symmetrically and spirally from near the center in the axial direction of the wound body toward both ends, or the axis of the wound body. It is preferable that the sheet has a symmetrical shape that spreads from both sides near the center in the direction. By using these sheets, it is possible to gradually apply a bilaterally symmetrical force from the central portion to the outside only by winding the sheet. In particular, by using the former sheet, an appropriate tightening force can be uniformly applied in the axial direction while suppressing the telescopic phenomenon, and the effect of increasing the overall adhesion can be more reliably obtained. In addition, by using the latter sheet, the winding thickness of the sheet is increased at the center of the wound body, so that a greater tightening force can be applied at the center of the wound body.
Further, it is preferable that the sheet constituting the exterior material has an adhesive layer. In this case, since the sheet has the pressure-sensitive adhesive layer, it is possible to maintain the wound state in which the tightening force has been applied only by winding the sheet.
On the other hand, the method for producing a spiral-wound membrane element of the present invention is characterized in that the separation membrane, the supply-side flow path material, and the permeation-side flow path material are perforated while at least the axial ends of the permeation-side flow path are sealed. In a method of manufacturing a spiral-type membrane element including a step of winding a sheet-like exterior material on a surface of a spirally wound body wound around a center tube of the above, the step of winding the exterior material includes the step of: It is characterized in that one or more sheets are wound substantially symmetrically so as to spread from near the center in the axial direction of the rotator to both ends.
According to the production method of the present invention, since the sheet as the exterior material is wound substantially symmetrically so as to spread from the vicinity of the center in the axial direction of the wound body to both ends, the sealing portions at both ends in the axial direction of the permeation-side flow path. Even when only the two ends in the axial direction of the wound body are thickened due to the thickness of the wound body, the force is first applied to the central part in the axial direction, so that the adhesion between the separation membrane, the supply-side flow path material, and the permeation-side flow path material can be improved. it can. Further, since the sheet is sequentially wound outward, the adhesiveness is improved at all portions, and the generation of wrinkles can be suppressed because excessive force is not applied to the sheet. Further, since the sheet is wound symmetrically from the center, the sheet is symmetrical in the axial direction and the telescope phenomenon does not occur. As a result, the performance of the spiral membrane element can be prevented from deteriorating.
In the above, it is preferable that the tension applied to the sheet when winding the sheet is 2 N or less per 1 mm in width. When winding is performed with such tension, an excessive force is less likely to be applied to the wound body, and wrinkles can be more reliably suppressed.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 are process diagrams illustrating an example of a method for manufacturing a spiral-type membrane element of the present invention. First, the wound body 1 according to the present invention will be described.
As shown in FIGS. 1 to 3, the wound body 1 of the present invention is configured such that the separation membrane 101, the supply-side flow path material 102, and the permeation-side flow path material 103 have at least both ends in the axial direction of the permeation-side flow path. It is wound spirally around a perforated central tube 105 in a sealed state. The wound body 1 in the present invention is not particularly different from that used for a conventional element, and any conventionally known one can be used. For example, an adhesive, a hot-melt adhesive, a heat-fusible pressure-sensitive adhesive tape, a heat-fusible sheet, or the like can be used to seal both ends in the axial direction of the permeation-side flow path.
The above-mentioned wound body 1 can be manufactured, for example, by the steps shown in FIGS. First, as shown in FIG. 1, one in which the supply-side flow path material 102 is disposed while the separation membrane 101 is folded in two, and the permeation-side flow path material 103 are stacked, and a seal for preventing mixing of the supply fluid and the permeate fluid is formed. The separation membrane unit U is prepared in which the adhesives 104 and 106 for forming the stop are applied to both ends in the axial direction of the permeation-side flow path member 103 and the end of the winding.
In the present embodiment, an example has been described in which the permeate-side flow path member 103 is superimposed on the separation membrane 101 folded in two so as to sandwich the supply-side flow path material 102 and the adhesives 104 and 106 are applied. It is also possible to stack the separation membrane 101 folded in two on the permeation-side channel member 103 and apply the adhesives 104 and 106 thereon. Further, instead of the two-folded separation membrane 101, a continuous membrane that is alternately folded may be used, or the separation membrane 101 may be arranged such that the folded part is on the winding end side.
As the separation membrane 101, a reverse osmosis membrane, an ultrafiltration membrane, a microfiltration membrane, a gas separation membrane, a degassing membrane, or the like can be used. A net-like material or the like can be used for the supply-side channel material 102. A net-shaped material, a knitted material, or the like can be used for the permeation-side channel material 103. Urethane, epoxy, or the like can be used for the adhesives 104 and 106.
Next, as shown in FIG. 2, one or more of the separation membrane units U are spirally wound around a perforated central tube 105, and then the adhesives 104 and 106 are cured by heat or the like. Thus, a wound body 1 in which both ends in the axial direction of the permeation-side flow path are sealed at least is obtained. In this embodiment, at this time, the winding end of the permeation-side flow path and the periphery of the central tube 105 are also sealed.
The number of lamination of the separation membrane units U is determined according to the required permeation flow rate, and may be one or more, but the upper limit is about 100 in consideration of operability.
The spiral-wound membrane element of the present invention is wound substantially symmetrically so that the exterior material provided on the surface of the wound body 1 as described above spreads from near the axial center of the wound body 1 to both end sides. It is characterized by a single or a plurality of sheets. Such a winding step of the exterior material can be performed by winding a single or a plurality of sheets substantially symmetrically so as to spread from near the center in the axial direction of the wound body 1 to both ends. At this time, the winding direction of the sheet is the same as the winding direction of the separation membrane unit U in the winding body 1.
In the present invention, to wind a sheet substantially symmetrically means to use a single left-right substantially symmetrical sheet, or to arrange a plurality of sheets substantially symmetrically left and right and wind it spirally. In the present embodiment, as shown in FIG. 3, an example in which the exterior material is an even number of sheets 2 wound substantially symmetrically and spirally from near the center in the axial direction of the wound body 1 to both end sides. Show.
In the present invention, the position near the axial center of the wound body 1 is preferably within a range of 20% of the axial length of the wound body 1 around the axial center. The winding start position of the sheet is located within this range. At the winding start position, the even number of sheets 2 may be connected, or two sheets obtained by folding one sheet into two at the start position may be wound.
In the present invention, the tension applied to the sheet when the sheet is wound is preferably 2 N or less per 1 mm width of the contact portion between the wound body 1 and the sheet, and more preferably 0.05 to 1 N per 1 mm width. . For example, by changing the tension applied to the entire sheet according to the winding width of the sheet, the above-described tension can be set to a desired value even when winding a sheet having a variable sheet width.
The sheet to be wound in the present invention preferably has an elongation of 10% or less in tension at the time of winding the sheet, as long as the sheet has flexibility so that it can be wound along the outer peripheral surface of the wound body 1, and is defined by a material and a shape. is not. For this reason, even if it is a sheet having a multilayer structure in which several types of sheets are laminated, fiber-reinforced, or an adhesive layer is formed inside the sheet, any sheet satisfying the above conditions can be used. . However, as a preferable sheet substrate, polyester, polypropylene, polyethylene, polyvinyl chloride, glass fiber cloth and the like can be used.
When a plurality of sheets 2 are arranged symmetrically and wound spirally as in the embodiment shown in FIG. 3, it is preferable that the spiral sheets overlap each other and have no gap. Specifically, the overlap of the sheets 2 is preferably set to 5 to 50% of the sheet width. Below this range, a gap is easily formed, and if a gap is formed, the adhesion between the separation membrane, the supply-side flow path material, and the permeation-side flow path material tends to be reduced. On the other hand, if it exceeds this range, the winding time of the sheet 2 and the usage amount of the sheet 2 increase, making it difficult to supply an inexpensive spiral membrane element. The width of the sheet 2 is preferably 20 to 200 mm, but the width of the sheet 2 may be changed in the longitudinal direction.
In the present embodiment, both ends of the strip-shaped sheet 2 are fixed to the center of the axial length of the wound body 1. The fixing method can be performed by a method such as sticking, fusing, and bonding. Each sheet 2 is spirally wound around the wound body 1 in a symmetrical shape with the center of the wound body 1 being a mirror surface. At that time, the spirally wound membrane element is obtained by winding up to both ends of the wound body 1 so that there is no gap between the sheets 2. In the illustrated example, the example in which the number of the sheets 2 is two has been described. However, the present invention may be implemented with an even number of sheets such as four or eight sheets that can be symmetrically wound.
The spiral membrane element of the present invention may be provided with a perforated end member for further preventing deformation (telescope or the like), a sealing material, a reinforcing material, and the like, if necessary.
[Other embodiments]
(1) In the above-described embodiment, an example is shown in which an even number of sheets are wound substantially symmetrically and spirally from the vicinity of the center in the axial direction of the wound body to both end sides. As shown in FIG. 4, the exterior material may be a symmetrical sheet 3 that extends from near the center in the axial direction of the wound body 1 to both end sides.
In this embodiment, for example, an isosceles triangular sheet 3 having a base length substantially equal to the axial length of the wound body 1 can be used. The vertex of the isosceles triangle of the sheet 3 is fixed to the center of the wound body 1 in the axial direction. The fixing method can be performed by a method such as sticking, fusing, bonding, etc., and the sheet 3 is wound around a roll to obtain a spiral membrane element.
(2) In the present invention, for example, the sheet shown in FIG. 5 can be used without being limited to those shown in FIGS. As shown in FIG. 5A, the symmetrical sheet 3 may have a trapezoidal shape, and as shown in FIG. 5B, the symmetrical sheet 3 may have a pentagonal shape. These oblique sides need not be straight lines. Further, as shown in FIG. 5 (c), the strip-shaped sheet 2 may be cut in the circumferential direction so that two sheets do not overlap, and the end side of the winding is also cut in the circumferential direction. Is also good.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process chart showing an example of a method for producing a spiral membrane element of the present invention, wherein (a) is a plan view and (b) is a front view. FIG. 3 is a process diagram showing an example of a method for manufacturing a spiral membrane element of the present invention. FIG. 4 is a process diagram showing another example of a method for manufacturing a spiral membrane element of the present invention. 5 is a plan view showing another example of a sheet used in the method for manufacturing a spiral-type membrane element of the present invention. FIG. 6 is a process chart showing a conventional method for manufacturing a spiral-type membrane element. FIG. 7 is a conventional spiral-type membrane. Process drawing showing element manufacturing method [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Winding body 2 Sheet 3 Sheet 101 Separation membrane 102 Supply side flow path material 103 Permeation side flow path material 105 Central pipe U Separation membrane unit

Claims (6)

The separation membrane, the supply-side flow path material, and the permeation-side flow path material are spirally wound around a perforated central tube with at least the axial ends of the permeation-side flow path sealed. In a spiral type membrane element having an exterior material on the surface of the body,
The spiral-type membrane element, wherein the exterior material is a single or a plurality of sheets wound substantially symmetrically so as to spread from near an axial center of the wound body to both end sides. The spiral membrane element according to claim 1, wherein the exterior material is an even number of sheets wound substantially symmetrically and spirally from near the center in the axial direction of the wound body toward both ends. 2. The spiral membrane element according to claim 1, wherein the exterior material is a symmetrical sheet that extends from near the center in the axial direction of the wound body to both end sides. The spiral membrane element according to any one of claims 1 to 3, wherein the sheet constituting the exterior material has an adhesive layer. A wound body in which the separation membrane, the supply-side flow path material, and the permeation-side flow path material are spirally wound around a perforated central tube with at least both ends in the axial direction of the permeation-side flow path sealed. In the method of manufacturing a spiral-type membrane element including a step of winding a sheet-like exterior material on the surface of,
The method of manufacturing a spiral-wound membrane element, wherein the step of winding the exterior member winds a single or a plurality of sheets substantially symmetrically so as to spread from near an axial center of the wound body to both end sides. The method for manufacturing a spiral-type membrane element according to claim 5, wherein a tension applied to the sheet when the sheet is wound is 2 N or less per 1 mm in width.

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