JP2008068162A - Water treatment filter and filter module - Google Patents

Abstract

A water treatment filter capable of contributing to the filtration of the entire membrane substantially uniformly and a filter module using the water treatment filter are provided.
A pleated body has a shape in which a flat film is folded back in a zigzag so that ridges 1a and ridges 1b are alternately arranged in parallel. A frame body 2 is disposed around the outer periphery of the pleat body 1, and an outer edge portion of the pleat body 1 is coupled to the frame body 2 to constitute a water treatment filter 4. In this embodiment, the outer edge portion of the pleat body 1 is embedded in the frame body 2 so that the outer edge portion is coupled to the frame body 2. The support body 3 is arrange | positioned so that the pleat body 1 may be pinched | interposed from both sides. The water treatment filters 5 are stacked between the frame bodies 2 via the O-rings 7, and the water collecting members 6 are stacked at both ends in the stacking direction.
[Selection] Figure 7

Description

  The present invention relates to a water treatment filter and a filter module used for water filtration, and in particular, a water treatment filter having a pleated body obtained by folding a flat membrane into a pleat shape, and a filter using the water treatment filter Regarding modules.

  In order to increase the membrane area of the filter medium of the flat membrane, a flat membrane folded in a pleated shape has already been widely used for water treatment.

A conventional pleat body is arranged so as to surround the outer periphery of a cylindrical core as described in JP-A-11-99307, and constitutes a cylindrical filter. In the publication, a plurality of cylindrical filters are arranged in a vessel, water is passed through the filter in a centripetal direction (a direction opposite to the radial direction), and treated water is taken out from the core.
JP-A-11-99307

  In the above cylindrical filter, the treated water is taken out from the core at one end side in the axial direction of the cylinder. In this case, the permeation flux increases toward the one end side of the cylinder, and the membrane surface The whole cannot contribute to the filtration evenly, and the removal rate becomes low.

  Further, in the filter disclosed in JP-A-11-99307, each pleat fold extends in the radial direction in a cross section perpendicular to the axial center line of the cylinder. The tip end in the direction becomes larger, and the tip end in the radial direction hardly contributes to filtration, and the removal rate may be lowered.

  An object of the present invention is to provide a water treatment filter that can eliminate the above-described conventional problems and contribute to the filtration of the entire membrane substantially evenly, and a filter module using the water treatment filter. To do.

  The water treatment filter of the present invention is a water treatment filter having a pleat body in which a flat membrane-like filter medium is folded back into a pleat shape, and the ridges and the recesses are alternately arranged in parallel. The surface connecting the tops of the ridges and the surface connecting the bottoms of the ridges are flat and substantially flat.

  This flat membrane filter medium desirably has an ion removing function.

  In the present invention, it is preferable that a frame body is disposed around the outer periphery of the pleat body, and an outer edge portion of the pleat body is coupled to the frame body.

  In this case, it is preferable that a support body is disposed with a flat pleated body interposed therebetween, and the support body is held by the frame body.

  As the support, a net or the like can be used.

  The filter module of the present invention includes a plurality of such water treatment filters with a frame, and the frames of each water treatment filter are stacked and bound by a binding member.

  The filter module preferably further includes a water collecting member that overlaps the water treatment filter at the end in the stacking direction.

  In the present invention, the pleated body has a flat shape, and the raw water can be supplied to the entire surface of one side of the pleated body substantially evenly, so that the entire membrane surface can contribute to the filtration substantially evenly.

  In the present invention, the water treatment filter can be easily handled by surrounding the pleat body with the frame and coupling the outer edge of the pleat body to the frame.

  In the present invention, by arranging a support such as a mesh body with the pleat body interposed therebetween, deformation such as bending of the pleat body during filtration water flow or backwashing can be prevented.

  The filter module of the present invention has a structure in which the above-mentioned water treatment filters with a frame are stacked and bound, and can be efficiently filtered in multiple stages. Further, membranes having different filtration characteristics, for example, water treatment filters having an ion removing function having different kinds of functional groups may be stacked.

  By providing a water collecting member at the end of the filter module in the stacking direction, water can be easily passed through the filter module.

  The water treatment filter and filter module of the present invention are ions that can remove trace metals suitable for water treatment in semiconductor manufacturing processes by using a filter membrane having a functional group having an ion removal function. Although the removal rate is high, the water treatment filter and filter module of the present invention can be used for various other water treatments.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a perspective view showing a pleat body of a water treatment filter according to the embodiment, FIG. 2 is a perspective view of the water treatment filter according to the embodiment, and FIG. 3 is a line III-III in FIG. 4 is a sectional view taken along the line IV-IV of FIG. 2, FIG. 5 is a dimensional view of the pleats, FIG. 6 is a sectional view of the water treatment filter according to the embodiment, and FIG. It is sectional drawing of the filter module which concerns on a form.

  The pleated body 1 has a shape in which the flat film is folded back zigzag so that the ridges 1a and the ridges 1b are alternately arranged in parallel. In addition, the surface which connects the top part of each protruding item | line 1a and the surface which connects the bottom part of each recessed item 1b exist on one plane, respectively, Thereby, the pleat body 1 becomes a flat shape. The surface connecting the tops of the ridges 1a coincides with the lower surface of the upper support 3 in FIG.

  The above flat membrane is preferably a non-woven fabric, a woven fabric, a porous membrane or the like to which an ion removing function is added, but is not limited thereto. The functional group for adding an ion removing function is preferably one or more of an anion exchange group, a cation exchange group, and a chelate forming group.

  The flat membrane may be composed of only a nonwoven fabric with an ion removing function, or may be a membrane in which other layers such as a porous membrane are laminated on the nonwoven fabric. Two or more flat films having the same or different characteristics may be laminated. The thickness of the flat membrane is usually about 0.1 to 1 mm, but is not limited thereto.

  The pitch p of the ridge 1a shown in FIG. 5 is preferably 0.5 to 10 mm, particularly 1 to 5 mm, and the depth h of the ridge 1b is preferably 5 to 100 mm, particularly 10 to 50 mm.

  A frame body 2 is disposed around the outer periphery of the pleat body 1, and an outer edge portion of the pleat body 1 is coupled to the frame body 2 to constitute a water treatment filter 4. In this embodiment, the outer edge portion of the pleat body 1 is embedded in the frame body 2 so that the outer edge portion is bonded to the frame body 2, but may be bonded by adhesion, welding, or the like.

  As shown in FIG. 2, a hole 2 a for inserting a bolt or a rod is penetrated in the frame 2 in the thickness direction of the filter 4.

  In order to embed the outer edge of the pleat body 1 in the frame body 2 as shown in FIGS. 3 and 4, the frame body 2 is made of a thermoplastic resin such as polyolefin, for example polyethylene, and the pleat body is used as a mold for molding the frame body 2. The frame 2 may be formed by inserting the outer edge portion 1 and supplying the thermoplastic resin to the mold. The frame body 2 may be formed using a curable resin material such as a potting material instead of the thermoplastic resin.

  The water treatment filter 4 shown in FIGS. 2 to 4 includes the pleat body 1 and the frame body 2. In the present invention, the pleat body 1 is disposed on both sides like the water treatment filter 5 shown in FIG. It is preferable that the support body 3 is arranged so as to be sandwiched between the frame body 2 and the outer edge portion of the support body 3 is also integrated with the frame body 2 by embedding or bonding (preferably embedding). By disposing the support body 3 in this manner, even if a water pressure is applied to the pleat body 1, the pleat body 1 is prevented from being bent or deformed.

  The support 3 is preferably a net such as a net or a lattice, but may be a plurality of rods arranged in parallel. In this case, it is preferable that the longitudinal direction of the rod-like body is a direction orthogonal to the extending direction of the ridges 1a and 1b.

  Further, when the support body 3 is provided, it is preferable that the support body 3 is within the range of the thickness direction of the frame body 2 so as not to protrude from the frame body 2 as shown in FIG.

  The other structure of FIG. 6 is the same as that of FIG. Also in this water treatment filter 5, the frame 2 is provided with holes 2a (not shown in FIG. 6).

  Water is passed through the water treatment filters 4 and 5 in a direction passing through the frame 2. Each of the water treatment filters 4 and 5 may be provided in only one stage or in multiple stages.

  When the water treatment filters are provided in multiple stages, it is preferable to combine the filter modules 10 as shown in FIG. In FIG. 7, the water treatment filters 5 are stacked between the frame bodies 2 via the O-rings 7, and the water collecting members 6 are stacked on both ends in the stacking direction to tie bolts 8 as binding members. Is inserted into the hole 2a of the frame body 2 and the hole of the water collecting member 6 (reference numeral is omitted; provided coaxially with the hole 2a), and the nut 9 is tightened to constitute the filter module 10.

  The water collecting member 6 is provided with an opening 6a for passing water and a header chamber 6b. The opening 6a faces the outer surface of the filter module 10, and the header chamber 6b is provided in a divergent shape so as to communicate the opening 6a and the inside of the frame 2 of the water treatment filter 5.

  Water to be treated is supplied from the opening 6 a of one water collecting member 6, and filtered water is taken out from the opening 6 a of the other water collecting member 6.

  Although the number of stacked layers of the water treatment filter 5 is 4 in FIG. 6, it is not limited to this. Usually, the number of stages is preferably about 2 to 5.

  In the water treatment filters 4 and 5 and the filter module 10 configured as described above, since water is uniformly supplied to the entire pleat body 1 of each water treatment filter, the filtration process is efficiently performed. be able to.

  In FIG. 7, the raw water is passed upward, but in this case, the largest load is applied to the pleat body 1 of the lowermost water treatment filter 5. Therefore, after performing the filtering treatment for a predetermined time, the filter module 10 is disassembled before breakthrough (ion leak) occurs in the pleat body of the lowermost water treatment filter 5, and the lowermost water treatment filter is disposed. It is preferable to arrange the filter 5 in the uppermost stage and reassemble the other water treatment filters 5 so that they are lowered one by one.

  In the present invention, when water treatment filters are combined in multiple stages as shown in FIG. 7, at least a part of the water treatment filter is used having a film having characteristics different from those of other water treatment filter films. May be. For example, a cation exchange membrane is used for some water treatment filters, an anion exchange membrane is used for other water treatment filters, and two or more functional functional groups are added to other water treatment filters. You may use what has the film | membrane which has.

[Example 1]
A pleated body is removed from a commercially available concentric pleated cation exchange filter (two cation exchange filters are used. The pleated body is cylindrical as shown in FIG. 8 of JP-A-11-99307). Was molded again into a flat mold, and then the polyethylene pellets were dissolved and fixed in a high-density polyethylene outer frame to produce a water treatment filter 4.

  The inner dimension of the frame 2 of the water treatment filter 4 is 200 × 10 mm, and the thickness of the frame 2 is 21 mm. The dimension (pitch) p of the pleat body 1 is 1.5 mm, and the pleat depth (dimension h) is 15 mm.

  Two water treatment filters 4 are overlapped to produce a filter module, ultrapure water prepared at a Na ion concentration of 2 ppt is passed at 20 L / min, and the Na ion concentration in the treated water is analyzed by ICP-MS. The result was 0.01 ppt.

  Further, when a solution obtained by diluting methylene blue, which is a cationic dye, with ultrapure water was passed through the flat filter module, the entire membrane surface was uniformly colored on both the entrance surface and the exit surface.

[Comparative Example 1]
The same commercially available concentric pleated cation exchange filter as used in Example 1 (outer diameter 76 mm, inner diameter 42 mm, axial length 215 mm) was prepared with 20 L / min of ultrapure water prepared at a Na ion concentration of 2 ppt. The water was passed through. The water flow direction was the centripetal direction. As a result of analyzing the Na ion concentration in the treated water by ICP-MS, it was 0.8 ppt.

  Moreover, when a solution obtained by diluting methylene blue, which is a cationic dye, with ultrapure water was passed through this concentric pleated cation exchange filter in the centripetal direction, the inlet surface of the water to be treated was dyed almost uniformly, but the outlet As for the surface, only the vicinity of the treated water outlet was stained.

It is a perspective view which shows the pleat body of the filter for water treatment which concerns on embodiment. It is a perspective view of the filter for water treatment concerning an embodiment. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a dimension figure of a pleat. It is sectional drawing of the filter for water treatment which concerns on embodiment. It is sectional drawing of the filter module which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pleated body 2 Frame 3 Support body 4,5 Filter for water treatment 6 Water collecting member 7 O-ring 8 Tie bolt

Claims (7)

In a water treatment filter having a pleated body in which a flat membrane-like filter medium is folded back into a pleat shape, and the ridges and recesses are alternately arranged in parallel,
The pleated body has a flat shape in which a surface connecting the tops of the ridges and a surface connecting the bottoms of the ridges are substantially flat.   2. The water treatment filter according to claim 1, wherein the flat membrane filter medium has an ion removing function.   The water treatment filter according to claim 1 or 2, wherein a frame body is disposed around an outer periphery of the pleat body, and an outer edge portion of the pleat body is coupled to the frame body.   4. The water treatment filter according to claim 3, wherein a support is disposed across the flat pleated body, and the support is held by the frame.   5. The water treatment filter according to claim 4, wherein the support is a net-like body. A filter module comprising a plurality of the water treatment filters according to claim 3,
A filter module, wherein frames of water treatment filters are stacked and bound by a binding member.   7. The filter module according to claim 6, further comprising a water collecting member that overlaps the water treatment filter at the end in the stacking direction.

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