JP3542206B2 - Hollow fiber membrane module laminate - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hollow fiber membrane module laminate used for filtering suspended substances contained in highly polluted water such as river water, night soil, sewage, waste water, and the like.
[0002]
[Prior art]
Hollow fiber membrane modules are widely used in the field of so-called microfiltration, such as the production of sterile water, drinking water, and high-purity water, and the purification of air, but are used in secondary, tertiary, and septic tanks in sewage treatment plants. Various uses in the field of highly polluted water treatment, such as solid-liquid separation of solid waste, solid-liquid separation of suspended suspended solids in industrial wastewater, direct filtration of river water in water purification plants, filtration of industrial water, and filtration of pool water Is being considered.
[0003]
The hollow fiber membrane module used in the field of high-pollutant water treatment is, in addition to the conventional cylindrical type in which hollow fiber membranes are bundled, a sheet type in which hollow fiber membranes are arranged in a sheet shape and one end is fixed to a support in recent years. Types have come to be used. The hollow fiber membrane module of this sheet type, when filtered, since the hollow fiber membrane is in an unconstrained state, the membrane function is easily recovered by intermittently or continuously cleaning the membrane surface by air scrubbing, Filtration can be performed, suspended substances are deposited on the membrane surface as in the cylindrical type hollow fiber membrane module, the hollow fiber membranes are fixed and integrated, the effective membrane area decreases, and the filtration flow rate decreases. It does not cause a problem of causing it.
[0004]
On the other hand, in a sheet-type hollow fiber membrane module, there is a demand for back-flow water washing and back-pressure washing with compressed air for increasing the membrane area, extending the life of the membrane, and the like. However, the sheet-type hollow fiber membrane module is used by stacking the hollow fiber membrane modules and forming a water collecting portion communicating with the hollow fiber membrane opening end of the sheet-like material fixing support portion. The greater the number of layers and the higher the cleaning efficiency, the more pressure resistance is required in the water collecting section.
[0005]
As means for improving the pressure resistance, there are methods such as increasing the thickness of the sheet-like object fixing support portion, changing the fixing support member to one having a high elastic modulus, and reducing deformation of the water collecting portion. However, there is a problem in terms of volume efficiency and member cost, and there is also a disadvantage that module weight is increased. In addition, there is a method of attaching a reinforcing material to the outside of the module laminate, but there is no effect on suction filtration, and there is no method of attaching a reinforcing material to the sheet-like material fixing support portion. Furthermore, the method of reducing the water collecting portion or dividing the holes of the sheet-like material fixing support portion forming the water collecting portion is not effective because the volumetric efficiency is reduced due to the decrease in the membrane area and the manufacturing process is complicated. Absent.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a hollow fiber membrane module laminate having a high volumetric efficiency and capable of arbitrarily increasing the membrane area while securing required pressure resistance.
[0007]
[Means for Solving the Problems]
The present invention comprises a knitted fabric in which hollow fiber membranes are arranged in one direction, and a rectangular plate-shaped frame formed by frame pieces, penetrating a longitudinally extending slit provided in at least one of the long frame pieces. One end of the knitted fabric in the same direction as the orientation of the hollow fiber membrane is inserted into the frame, the end of the hollow fiber membrane at the end of the knitted fabric is kept open in the frame, and the knitted fabric is sealed with resin at the slit portion. A plurality of formed hollow fiber membrane modules are laminated and fixed at the plate-shaped frame portion, and a plate-shaped reinforcing member having a through-hole for liquid flow and having the same shape as the plate-shaped frame is provided between the plate-shaped frames of the laminated module. And a hollow fiber membrane module laminate.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention will be described in detail with reference to the drawings.
FIG. 1 is a partial perspective view of an example of a hollow fiber membrane module laminate of the present invention, FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1, and FIG. FIG. 4 is a perspective view of an example of a plate-like reinforcing member according to the present invention. In the figure, 1 is a hollow fiber membrane array knitted fabric, 2 is a fixing resin, 3 is a hollow fiber membrane opening, 4 is a plate-like frame, 5 is a slit, 6 is a plate-like reinforcing body, 7 is a water collecting unit lid, 8 is a holding rod, 41 and 61 are O-ring grooves, 42 is an O-ring for a frame, 43 and 63 are fitting concave and convex portions, 64 is a liquid flow through hole, 65 is a rod insertion hole, 71 is a water collecting port, and 81 is a water collecting port. Represents an O-ring for a rod.
[0009]
In FIG. 1, the hollow fiber membrane-arranged knitted fabric 1 has a frame in which one end in the same direction as the orientation of the hollow fiber membrane passes through a longitudinally extending slit 5 provided in one of the long frame pieces of the plate-shaped frame 4. A plurality of hollow fiber membrane modules, each of which is inserted into the inner surface of a laminated frame 4 and is formed by sealing a knitted woven fabric with a fixing resin 2 at a slit portion, are laminated and fixed at a portion of the plate-shaped frame 4, and the laminated module A plate-like reinforcing body 6 is disposed between the frames, and a water collecting portion lid 7 having water collecting ports 71 is provided on both sides of the laminate, and the entire integrated body is tightly fixed by a holding rod 8.
[0010]
In FIG. 2, the hollow fiber membrane module 3 has a hollow fiber membrane opening 3 at the end of a knitted fabric inside each plate frame 4 of the plurality of laminated hollow fiber membrane modules. A water collecting portion communicating with each frame is formed by a laminated portion of the plate-shaped frame 4 having the three.
[0011]
As shown in FIG. 3, the hollow fiber membrane module includes a hollow fiber membrane array knitted fabric 1 in which hollow fiber membranes are arranged in one direction, and a rectangular plate-shaped frame 4 formed by frame pieces. One end of the knitted fabric in the same direction as the orientation of the hollow fiber membrane is inserted into the frame 4 through the slit 5 extending in the longitudinal direction provided on one of the Form an opening 3, and a knitted fabric 1 including a hollow fiber membrane is sealed at a slit 5 portion with a fixing resin 2. The side surface of the plate-shaped frame 4 is provided with a fitting concave-convex portion 43 so as to prevent a displacement due to internal pressure after lamination, and an O-ring groove 41 is provided on the side surface.
[0012]
Further, the hollow fiber membrane module uses two plate-like frames, and a slit extending in the longitudinal direction provided on one of the long frame pieces of each plate-like frame at both ends of the knitted fabric in the same direction as the orientation of the hollow fiber membrane. May be inserted into the frame, an opening may be formed at the end of the hollow fiber membrane at both ends of the knitted fabric in the frame, and the knitted fabric may be sealed with a fixing resin at the slit portion, Inserting one end of the knitted fabric in the same direction as the orientation of the hollow fiber membrane through the respective slits extending in the longitudinal direction provided on both long frame pieces of one plate-like frame into the same frame, An opening may be formed at the end of the hollow fiber membrane at the end of the knitted fabric, and the knitted fabric may be sealed with a fixing resin at the slit.
[0013]
As shown in FIG. 4, the plate-shaped reinforcing member disposed between the stacked hollow fiber membrane modules has a through-hole 64 for liquid flow, and has the same external shape as the plate-shaped frame 4. On the side surface of the plate-shaped reinforcing member 6, a fitting uneven portion 63 is provided so as to prevent displacement due to internal pressure after lamination with the plate-shaped frame 4, and an O-ring groove 61 is provided on the side surface. . The plate-shaped reinforcing member 6 has an insertion hole 65 for a holding rod. The through holes 64 for the liquid flow are sized or numbered so as not to impair the reinforcing effect of the plate-shaped reinforcing member 6.
[0014]
As shown in FIG. 3, the hollow fiber membrane module is stacked by filling an O-ring 42 into an O-ring groove 41 on the side surface of the plate-shaped frame 4 and fitting the same to each other by a fitting concave-convex portion 43 to obtain a predetermined membrane area. The required number of modules is fixed by lamination. Further, as shown in FIG. 4, the plate-like reinforcement 6 is mounted between the laminated hollow fiber membrane modules by inserting an O-ring 62 into an O-ring groove 61 on a side surface of the plate-like reinforcement 6. It is fitted and fixed to the plate-shaped frame 4 of the module by the fitting concave-convex portion 63, and is arranged at an arbitrary predetermined position.
[0015]
As shown in FIG. 1, a water collecting portion lid 7 having a water collecting port 71 is provided on both sides of the laminated body of the hollow fiber membrane module with the plate-like reinforcing member interposed therebetween, and is integrated by a holding rod 8. The whole body is tightly fixed. The water collecting unit lid 7 and the laminate are fitted with a concave-convex structure and an O-ring to prevent misalignment in the same manner as the plate-like frames of the hollow fiber membrane module or the laminated surface of the plate-like frame and the plate-like reinforcement. It is preferable to fix.
[0016]
The lamination and fixing of the hollow fiber membrane module with the plate-shaped frame 4, the plate-shaped reinforcing member 6, and the water collecting portion lid 7 need to be free from leakage from the laminated portion. It is preferable to fix with an O-ring, but as another method, the lamination may be fixed with an adhesive or a combination of an adhesive and an O-ring.
[0017]
Further, the laminated fixed portion of the hollow fiber membrane module with the plate-shaped frame 4, the plate-shaped reinforcing member 6 and the water collecting portion cover 7, and further the entire laminated body is pressed by a holding rod 8, if necessary, to a metal plate or the like. It is preferable to use a plate and fasten tightly. The holding rod 8 penetrates through the rod insertion hole of each plate-shaped frame of the laminate and the plate-shaped reinforcement, and is tightened with screws provided at the rod ends with the water collecting part covers at both ends. It is preferable to provide an O-ring 81 at the rod portion of the water collecting portion lid 7 that abuts the rod insertion hole so as to prevent leakage, and seal the rod portion. The number of the holding rods 8 is determined according to the configuration of the laminated body. However, when the number of stacked modules is small and the fixing with the plate-shaped frame and the plate-shaped reinforcing body is sufficient, the holding rod is not used. May be.
[0018]
A water collecting port 71 provided in the water collecting section lid 7 is for guiding and discharging the liquid in the water collecting section filtered by the hollow fiber membrane of each hollow fiber membrane module by an appropriate suction system. The water cover 7 is provided with a required number according to the configuration of the hollow fiber membrane module of the laminate, wastewater to be treated, and the like.
[0019]
In the laminate of the hollow fiber membrane module of the present invention, the water collecting portion of the laminate is subjected to suction pressure at the time of suction filtration, and pressurization at the time of back water washing or back pressure washing with compressed air. Deformation of the frame supporting the hollow fiber membrane occurs, and particularly when the frame is rectangular, maximum deflection occurs at the center of the long frame piece. Assuming that the frames are completely densely stacked, the thickness of the frame is W, the width of the frame is D, the number of layers is N, and if D> (W × N), the thickness t of the frame piece is deflected. When the amount of deformation is sufficiently small compared to the amount of deformation ω, according to the theory of micro deflection,
Maximum deflection ω = α ₂ × (p × (W × N) ⁴ ) / E × t ³
(Where p: pressure, α ₂ : coefficient, E: elastic coefficient)
It becomes.
[0020]
Here, when the through-hole of the holding rod is sufficiently small, the deformation of the plate-like reinforcing member due to the pressure can be ignored, so that the amount of flexural deformation can be set to zero in the plate-like reinforcing member. Therefore, when the plate-like reinforcing member is disposed in the middle of the laminate, the value of (W × N) is １ ／, and if the value of the coefficient α ₂ determined by the aspect ratio of the flexible surface is approximately the same. , The maximum deflection ω is 1/16. As is clear from the equation of maximum deflection, the most effective way to reduce the amount of deflection is to increase the thickness t of the frame piece or change the material to a material having a high elastic modulus (W × N). In the present invention, by disposing the plate-like reinforcing members between the laminates, the total number of laminates is increased, and the pressure resistance of the water collecting portion is improved.
[0021]
Examples of the hollow fiber membrane used in the hollow fiber membrane module in the present invention include those made of materials such as cellulose, polyolefin, polyvinyl alcohol, polymethyl methacrylate, and polysulfone, such as polyethylene and polypropylene. A hollow fiber membrane having high strength and elongation is preferably used. Further, the hollow fiber membrane is not particularly limited in its pore size, porosity, film thickness, outer diameter, etc., as long as it can be used as a filtration membrane, and is appropriately selected depending on a suspended substance to be filtered, Further, when the purpose is to remove organic substances and viruses, an ultrafiltration membrane having a molecular weight cutoff of tens of thousands to hundreds of thousands may be used.
[0022]
Further, the hollow fiber membrane used is preferably a hydrophilic hollow fiber membrane such as a hollow fiber membrane whose surface is hydrophilized with an ethylene / vinyl alcohol copolymer, polyvinyl alcohol or the like. In some cases, the adsorption of lipophilic substances is suppressed and the filtration performance is maintained for a long time.
[0023]
In the present invention, the hollow fiber membrane of the module is used in the form of a knitted fabric in which the hollow fiber membranes are arranged in one direction. Knitted fabrics and the like are mentioned, and the manufacturing method thereof is disclosed in, for example, JP-A-62-57965 and JP-A-1-266258. The knitted fabric in which the hollow fiber membranes are arranged in one direction may be one sheet, but it is preferable to use a plurality of layers in order to increase the membrane area.
[0024]
In the hollow fiber membrane module, one end of the knitted fabric in the same direction as the orientation of the hollow fiber membrane is inserted through the slit extending in the longitudinal direction provided in the frame piece of the plate-shaped frame, and inserted into the frame. The end of the hollow fiber membrane is opened, the knitted fabric is sealed and fixed with a fixing resin at the slit, and the number of slits provided in the frame piece may be one or more. For example, as proposed by the applicant in Japanese Patent Application No. 6-30132, such a module is provided with a potting mold below the slit portion of the frame piece, fills the fixing resin up to the slit portion, and fills one end of the knitted fabric. After the resin is inserted into the slit, cured and adhered and fixed, the potting mold is removed and the solidified portion is cut.
[0025]
As the fixing resin, for example, an epoxy resin, an unsaturated polyester resin, a polyurethane resin, or the like is used, and the resin viscosity when used is preferably about 1000 to 2500 centipoise. When the mold method is used, it is preferable that a mold release agent is applied to the inner surface of the potting mold so that the fixing resin does not adhere to the inner surface, or that the mold itself is made of a material having a high mold release property.
[0026]
In the hollow fiber membrane module of the present invention, the hollow fiber membrane is used as a knitted fabric in which the hollow fiber membranes are arranged in one direction, so that the arrangement density of the hollow fiber membranes can be arbitrarily changed depending on the knitted fabric structure. In addition, it can be fixed without bias of filling with the fixing resin.
[0027]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples.
Sixteen polyethylene porous hollow fiber membranes (manufactured by Mitsubishi Rayon Co., Ltd., EHF270T, inner diameter 270 μm, outer diameter 380 μm) are plied, and the hollow fiber membrane hydrophilized by treatment with an ethylene / vinyl alcohol copolymer is used as the weft. A knitted fabric having a width of 700 mm and a knitting length of 320 mm was knitted.
[0028]
As a plate-shaped frame, an ABS plate having a length of 480 mm, a height of 50 mm, and a thickness of 24 mm was formed as a hollow frame, and two slits having a length of 330 mm and a width of 5 mm were formed in one of the long frame pieces. A potting form made of silicone rubber was prepared and placed immediately below the slit. Polyurethane resin is injected into the mold from the slit, and the previously produced knitted fabric is aligned in the hollow fiber membrane arrangement direction, and two sheets are overlapped, and one end of the knitted fabric in the hollow fiber membrane arrangement direction hits the mold from each slit. After insertion, the resin was cured. Thereafter, the mold was removed, and the solidified portion below the slit was cut with a cutter. This operation was also performed at the other end of the knitted fabric, and a hollow fiber membrane module having an effective membrane area of about 4 m ² was prepared, in which both ends of the knitted fabric had openings of the hollow fiber membrane in the frame.
[0029]
Seven hollow fiber membrane modules are laminated with an O-ring at the plate-shaped frame portion, an ABS plate having a length of 480 mm, a height of 50 mm and a thickness of 12 mm is laminated as a reinforcing plate, and a further seven hollow fiber membrane modules are laminated. The layers were laminated, and a water collecting section lid having water collecting ports at both ends of the laminated body was respectively mounted. The obtained hollow fiber membrane module laminate had a membrane area of about 55 m ² , and the hollow fiber oriented knitted fabrics were arranged at a pitch of approximately 12 mm, and had a very high volumetric efficiency. In this hollow fiber membrane module laminate, the deformation due to the internal pressure of the water collecting portion was about 1/10 or less as compared with the laminate without the reinforcing plate, and the pressure resistance was remarkably improved.
[0030]
【The invention's effect】
The hollow fiber membrane module laminate according to the present invention has improved pressure resistance by arranging a plate-like reinforcing body between the laminates, and can be a hollow fiber membrane module laminate having a desired membrane area. In addition, since it has high volumetric efficiency, it is useful for filtering suspended substances contained in highly polluted water such as river water, night soil, sewage, and wastewater.
[Brief description of the drawings]
FIG. 1 is a partial perspective view of an example of a hollow fiber membrane module laminate of the present invention.
FIG. 2 is a sectional view taken along line AA ′ of FIG. 1;
FIG. 3 is a partial perspective view of an example of a hollow fiber membrane module according to the present invention.
FIG. 4 is a perspective view of an example of a plate-like reinforcement according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hollow fiber membrane arrangement knitted fabric 2 Fixing resin 3 Hollow fiber membrane opening 4 Plate-shaped frame 41 O-ring groove 42 O-ring 43 Fitting uneven part 6 Plate-shaped reinforcing body 61 O-ring groove 62 O-ring 63 Fitting uneven part 64 Liquid flow through hole 65 Holding rod insertion hole 7 Water collecting section lid 71 Water collecting port 8 Holding rod 81 O-ring for rod

Claims (1)

A knitted fabric in which hollow fiber membranes are arranged in one direction, and a rectangular plate-shaped frame formed by frame pieces, penetrating a longitudinally extending slit provided in at least one of the long frame pieces, and forming a hollow fiber membrane. One end of the knitted fabric in the same direction as the orientation is inserted into the frame, the end of the hollow fiber membrane at the end of the knitted fabric is kept open in the frame, and the knitted fabric is sealed with resin at the slit portion. The hollow fiber membrane module is laminated and fixed in the plate-shaped frame portion, and a plate-shaped reinforcing member having a through-hole for liquid flow and having the same shape as the plate-shaped frame is disposed between the plate-shaped frames of the laminated module. A hollow fiber membrane module laminate characterized by the above-mentioned.

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