JP4563060B2 - Manufacturing method of spiral membrane element - Google Patents

Description

  The present invention relates to a method for manufacturing a spiral membrane element 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 laminated state.

  A conventional spiral membrane element is a perforated hollow tube comprising a set of laminated bodies (membrane leaves) in which three sides are sealed in a bag shape with a permeate-side channel material interposed on the permeate side of two membranes. There has been known a structure in which the connected laminated body is wound in a spiral shape with a supply-side channel material interposed therebetween. Also known is a method using a plurality of laminated bodies (film leaves) in order to shorten the flow path length on the permeate side.

  The basic structure of the latter is that a laminated body in which a supply-side channel material is interposed on the supply side of the opposing membrane and a transmission-side channel material is interposed on the transmission side of the opposing membrane is spiraled in a perforated hollow tube. In general, those having a sealing structure for preventing the supply-side fluid and the permeation-side fluid from mixing are wound. More specifically, a single or a plurality of laminates of a membrane material group including a bi-fold membrane leaf sandwiching the supply-side channel material on the separation layer side of the membrane and a permeate-side channel material adjacent thereto are provided. What was wound around the hollow tube of a hole is already well-known (for example, refer patent document 1).

  As a manufacturing method of such a spiral membrane element, as shown in FIGS. 3 to 4, first, the membrane leaf composed of the folded membrane 1 and the supply-side channel material 11 and the permeation-side channel material 12 are overlapped. And a laminated body is produced by shifting this by a certain interval (the length obtained by dividing the outer peripheral length of the hollow tube 14 by the number of membrane leaves), and then the laminated body is wound around the hollow tube 14. Is used. 3 to 4 exemplify a form in which the membrane leaves are not continuous independently (single leaf), but a form in which the film 1 of each film leaf is continuous is also known.

  In the manufacturing method described above, in order to produce a membrane leaf, it is necessary to fold the membrane at a right angle with respect to the winding direction in order not to cause a shift or wrinkle. At this time, if only the film is folded, the film is likely to be defective at the fold, and therefore, the film may be protected by attaching an adhesive tape to the fold. In this state, there is a method in which the film is folded at a right angle, and the folded portion is creased with a hand, a plastic plate, a roller or the like to form a fold.

  In addition, there is also known a method in which lines or perforations are put in advance in the separation membrane in order to improve the straightness and perpendicularity accuracy of the fold (see, for example, Patent Document 2). Furthermore, a method of applying a crease by applying heat and a method of sandwiching a film with a pair of rolls at that time are also known (see, for example, Patent Document 3).

  However, in the method of simply forming the lines or perforations, the creases are not sufficiently formed, and this causes distortion in the subsequent winding process and the like, and “wrinkles” and “folds” easily occur. In addition, since the accuracy of straightness and perpendicularity of the fold is poor in the method of simply heating, and it is necessary to use a high temperature in order to make a sufficient crease (350 to 420 K (77 to 147 ° C.), the fold portion “Wrinkles” and “folding” occur due to the effects of distortion due to heat shrinkage of the material, and there are holes in the membrane. It was hard to say that it was a suitable method.

  On the other hand, as a method that can be automated, a method using the apparatus shown in FIG. 6 is known when the separation membrane is folded in two (for example, Patent Document 4). In this apparatus, the end portion of the separation membrane 1 is grasped by the gripping portion 61 of the transfer arm 60, folded and overlapped with each other, the crease guide 66 is moved to the front of the folded end 70, and then heated from above by the heat plate 67. A crease is applied by pressing.

However, in the above method, when the end of the separation membrane is grasped and folded to overlap each other, the membrane surfaces are rubbed with each other, and the membrane surface is easily damaged, resulting in a defect that impairs the separation performance of the spiral membrane element. There is a risk of causing. In addition, when pressure is applied to the folded end, the folded end portion is unstable, so that there is a problem that wrinkles are likely to occur at the fold portion. Furthermore, there is a problem that the crease position tends to fluctuate for complicated operations and controls.
U.S. Pat. No. 3,417,870 JP-A-10-137559 US Pat. No. 5,681,467 JP 2002-102659 A

  Accordingly, an object of the present invention is to provide a method of manufacturing a spiral membrane element suitable for automation because the membrane surface is less likely to be damaged, can be given a crease without wrinkles at a predetermined position, and is easy to operate. is there.

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

  That is, the spiral membrane element manufacturing method of the present invention includes a step of forming a laminate in which a supply-side channel material is disposed on the supply side of the folded membrane and a permeation-side channel material is disposed on the transmission side, and at least the lamination In a method for manufacturing a spiral membrane element, the method includes: a step of spirally winding a body around a perforated hollow tube; and a step of forming a sealing structure for preventing mixing of a supply-side fluid and a permeation-side fluid When folding the membrane, the folded portion of the membrane is pushed between the pair of sandwiching members whose mutual distances can be changed by the insertion member, and then the pushed portion is sandwiched by the sandwiching member to form a fold. It is characterized by.

  According to the present invention, since the fold can be formed only by the pushing operation and the pinching operation, the operation and control are simplified and suitable for automation. Further, since the position of the fold can be determined by the position where the insertion member pushes the film, the crease can be given at a predetermined position. At that time, a crease is formed without difficulty by pushing and clamping, so that wrinkles and distortion are less likely to occur.

  In the above, it is preferable that the cutting edge portion of the insertion member has a curvature radius in a range of 0.2 to 1.0 mm. With such a blade edge part, a crease can be temporarily attached without cutting the film when the film is pushed. By such temporary attachment of the folds, the folds can be stably formed when sandwiched.

  Moreover, it is preferable that the pressing force at the time of pinching with the said clamping member is the range of 10-500 KPa. With such a pressing force, a sufficient crease can be formed when the subsequent lamination process or winding process is performed while maintaining the performance of the film.

  Further, it is preferable that an adhesive tape is attached to the folded portion in advance on the folded inner side. With such an adhesive tape, it is possible to more reliably prevent deterioration of film performance due to pressing force.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 4 are process diagrams showing an example of the spiral membrane element manufacturing method of the present invention.

  In the present invention, as shown in FIGS. 1A to 1C, when the membrane 1 is folded in advance, the folded portion of the membrane 1 is inserted between the pair of sandwiching members 4 whose distance can be changed by the insertion member 3. After that, the fold 1a is formed by sandwiching the pushed portion with the holding member 4. In the present embodiment, an example is shown in which the sandwiching member 4 is a pair of rollers 4a and 4b having axes arranged in parallel.

  First, as shown in FIG. 1A, the folded portion of the separation membrane 1 is set between the push-in insertion member 3 and the rollers 4a and 4b. The separation membrane 1 is supported by a plurality of support rollers 6, and the separation membrane 1 can be automatically conveyed by driving some of these.

  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. In this example, the adhesive tape 2 for reinforcement is attached to the bent portion. Based on the adhesive tape 2 or the marking, it is also possible to position the conveyance.

  Examples of the adhesive tape 2 include those using polyethylene terephthalate, polypropylene, polyvinyl chloride or the like as a base material, and using an acrylic adhesive or the like in the adhesive layer.

  Subsequently, as illustrated in FIG. 1B, the folded portion of the film 1 is pushed between the rollers 4 a and 4 b by the insertion member 3. At this time, the distance of the narrowest part between the rollers 4a and 4b is 0.7-5. mm is preferred. In the present embodiment, it is preferable that the tip of the folded portion of the film 1 passes through at least the narrowest portion.

  The rollers 4a and 4b may be rotatable, but may be applied with a braking force or may not be rotatable. Further, rotation driving may be performed. When the insertion member 3 is inserted, it is rotated in synchronism with the insertion member 3, and the rollers 4 a and 4 b are rotated and driven reversely when the pressed portion of the film 1 is clamped. Thus, the membrane 1 may be pulled out and sandwiched.

  The insertion member 3 may be any member that can linearly abut against the membrane 1 and can be inserted between the holding members 4. For example, a blade or a plate can be used. Furthermore, it is preferable that the shape of the tip of the blade 3a of the insertion member 3 is not sharp (cornered) as shown in FIG. Specifically, it is preferable that the curvature radius r of the blade edge portion is in a range of 0.2 to 1.0 mm.

  The insertion member 3 is preferably movable in a direction substantially perpendicular to a plane including the axis of the roller 4a and the axis of the roller 4b. For example, this operation can be performed using a fluid pressure cylinder or other actuator, which enables automation.

  When the insertion member 3 is inserted between the rollers 4a and 4b, the distance of the narrowest portion between the rollers 4a and 4b may be changed according to the shape of the insertion member 3. In this case, the rollers 4a and 4b may be in contact with each other before the insertion member 3 is inserted.

  Subsequently, as shown in FIG. 1C, the pressed portion of the film 1 is sandwiched by the sandwiching member 4 to form a fold 1a. At this time, both the rollers 4a and 4b move toward the center, and the distance of the narrowest portion between them becomes narrow. At substantially the same time, the insertion part is pulled out. The rollers 4a and 4b can be moved by driving a member supporting the shaft with an air cylinder or the like. Further, when performing the above clamping, the rollers 4a and 4b can be moved up and down.

  In that case, it is preferable that the pressing force at the time of pinching with the clamping member 4 is in the range of 10 to 500 KPa, and particularly preferably in the range of 50 to 150 KPa. The pressing force is preferably 100 to 5000 N / cm per width of the film 1.

  In addition, you may provide a heating means in the clamping member 4, and what is necessary is just to incorporate a heat-transfer heater etc. in the rollers 4a and 4b, for example. As temperature at the time of a heating, 80-160 degreeC is preferable.

  The present invention includes a step of forming a laminate in which a supply-side channel material is disposed on the supply side of the membrane folded as described above and a permeation-side channel material is disposed on the permeation side, and at least the laminate is perforated. A step of spirally winding the hollow tube, and a step of forming a sealing structure for preventing mixing of the supply side fluid and the permeate side fluid.

  Specifically, as shown in FIG. 3, for example, the supply-side flow path material 11 and the permeation-side flow path material 12 are stacked and supplied while the separation membrane 1 with the crease is folded in two. A separation membrane unit U is prepared in which an adhesive 13 for forming a sealing portion that prevents mixing of fluid and permeating fluid is applied to both axial end portions and winding end portions of the permeate-side flow path member 12.

  In the present embodiment, the example has been described in which the permeation-side flow path material 12 is stacked on the separation membrane 1 folded in half so as to sandwich the supply-side flow path material 11, and the adhesive 13 is applied. It is also possible to superimpose the folded separation membrane 1 on the channel material 12 and apply the adhesive 13 thereon. Further, instead of the bifurcated separation membrane 1, continuous membranes that are alternately folded may be used, or the separation portion of the separation membrane 1 may be disposed on the winding end side.

  A net-like material or the like can be used for the supply-side channel material 11. A net-like or knitted material or the like can be used for the permeate-side channel material 12. Urethane, epoxy, or the like can be used for the adhesive 13.

  Next, as shown in FIG. 4, after winding one or more of the separation membrane units U around the perforated central tube 14 in a spiral shape, the adhesive 13 is cured by heat or the like, A wound body is obtained in which both end portions in the axial direction of the permeate side channel are sealed. In the present embodiment, the winding end portion of the permeate side channel and the peripheral portion of the center tube 14 are also sealed at that time. 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 the upper limit is about 100 layers in consideration of operability.

[Other Embodiments]
(1) In the above-described embodiment, an example in which the sandwiching member is a pair of rollers arranged in parallel with the axis is shown. However, in the present invention, the sandwiching member may be configured by a pinch bar, a pinch plate, or the like.

  For example, as shown in FIG. 5, a pair of pinch bars 4 c and 4 d having press surfaces arranged in parallel can be used as the clamping member 4. In order to facilitate the pushing-in of the film 1, it is preferable that the pinch bars 4c and 4d have a rounded sliding surface inside the upper surface. Even when the pinch bars 4c and 4d are used, it is preferable that both move symmetrically toward the center.

  (2) In the above-described embodiment, an example is shown in which the separation membrane 1 is arranged in a horizontal state, but the angle at which the separation membrane 1 is placed can be freely set. For example, it is possible to incline the mounting surface from the horizontal so that the separation membrane 1 can be easily automatically conveyed by the free rotation of the support roller 6.

  (3) In the above-described embodiment, an example in which a reinforcing material such as an adhesive tape is attached to the folded portion of the film is shown. However, when the strength of the film is sufficient, the film is folded alone without using the reinforcing material. May be performed. In addition, when the membrane is pushed in by the insertion member, the supply-side channel material or the like may be pushed together to simultaneously form the fold and sandwich the channel material.

  (4) In the above-described embodiment, the example in which the film is folded in half and the fold line is formed on the winding start side when the supply-side channel material is sandwiched is shown, but the continuous film is alternately folded and supplied. When the side channel material and the permeation side channel material are sandwiched, folds may be formed in the folded portions on both sides according to the present invention.

Process drawing which shows an example of the manufacturing method of the spiral type membrane element of this invention The principal part enlarged view which shows an example of the front-end | tip part of the pushing insertion member of this invention Process drawing which shows an example of the manufacturing method of the spiral type membrane element of this invention Process drawing which shows an example of the manufacturing method of the spiral type membrane element of this invention Process drawing which shows the other example of the manufacturing method of the spiral type membrane element of this invention Process drawing showing an example of a conventional method for manufacturing a spiral membrane element

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Separation membrane 2 Adhesive tape 3 Insertion member 3a Blade 4 Clamping member 4a, 4b Roller 4c, 4d Pinch bar 11 Supply side channel material 12 Permeation side channel material 13 Adhesive material 14 Perforated center tube U Separation membrane unit

Claims (5)

Forming a laminated body in which a supply-side channel material is arranged on the supply side of the folded membrane and a transmission-side channel material is arranged on the permeation side, and at least the laminate is spirally wound around a perforated hollow tube And a method of manufacturing a spiral membrane element having a step of forming a sealing structure for preventing mixing of a supply side fluid and a permeate side fluid,
When the film is folded, the folded portion of the film is pushed between the pair of sandwiching members whose distances can be changed by an insert member having a chamfered tip, and then the mutual distance between the pair of sandwiching members is determined. A method for producing a spiral-type membrane element, characterized in that a fold is formed by pinching a narrowed and pushed portion between the pinching members.   The method of manufacturing a spiral membrane element according to claim 1, wherein the cutting edge of the insertion member has a radius of curvature in the range of 0.2 to 1.0 mm.   3. The method for manufacturing a spiral membrane element according to claim 1, wherein a pressing force when sandwiched by the sandwiching member is in a range of 10 to 500 kPa.   The method for producing a spiral membrane element according to any one of claims 1 to 3, wherein an adhesive tape is attached in advance to the folded portion on the folded portion. The method for manufacturing a spiral membrane element according to any one of claims 1 to 4 , wherein the insertion member has a tapered shape.

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