JP3455589B2 - Hollow fiber membrane module assembly - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber membrane module assembly formed by combining a plurality of hollow fiber membrane modules, and more particularly to a hollow fiber membrane module assembly suitable for filtering highly polluted liquid. .

[0002]

2. Description of the Related Art Conventionally, hollow fiber membrane modules have been manufactured using sterile water,
It has been widely used in the field of so-called microfiltration such as the production of drinking water and high-purity water and the purification of air, but in recent years, it has been highly polluted by secondary and tertiary treatments at sewage treatment plants and solid-liquid separation in septic tanks. Various types of studies have been conducted for use in water treatment applications.

Most of the hollow fiber membrane modules used in these fields are of the cylindrical type in which the hollow fiber membranes are arranged concentrically in a circular shape or concentric circles which have been used in the field of conventional microfiltration. Met. Further, even if improvements are made, most of them merely change the filling rate or filling form of the hollow fiber membrane.

[0004]

Highly polluted water (for example, SS ≧ 5) is obtained by using such a conventional hollow fiber membrane module.
(0 ppm, TOC ≧ 100 ppm), the hollow fiber membranes are integrated (bonded) to each other through the deposits such as organic substances attached to the surface of the hollow fiber membranes due to use. As a result, the effective membrane area of the hollow fiber membrane in the module was reduced, and the filtration flow rate was rapidly reduced.
In particular, this phenomenon was remarkable in the hollow fiber membrane in the central portion of the cylindrical module, and was more remarkable in the large-sized one.

Further, even when the hollow fiber membrane module in which the hollow fiber membranes are fixed and integrated as described above is regularly subjected to membrane surface cleaning or backwashing, it is easy to recover the function of the module once fixed and integrated. However, there was a decrease in cleaning efficiency.

As a solution to this problem, in place of the concentrating and cylindrical hollow fiber membrane module, a large number of hollow fiber membranes are arranged in a sheet form and arranged so that one end or both ends of the hollow fiber membrane are A hollow fiber membrane module which is fixed in one or two different structural members with respective fixing members while maintaining an open state, and the shape of the cross section of the fixing member perpendicular to the hollow fiber membranes is an elongated rectangular shape. A hollow fiber membrane module has been proposed (Japanese Patent Laid-Open No. 5-220356).

Further, in order to dispose such a hollow fiber membrane module in the treatment tank in a volumetric efficient manner and to efficiently perform the recovery processing of the filtration function of the module, the sheet shape of the hollow fiber membrane in each module is used. There has been proposed a hollow fiber membrane module assembly in which objects are arranged so as to be parallel to each other (JP-A-6-344).

However, if this hollow fiber membrane module assembly is used for a long period of time and especially scrubbing cleaning (cleaning by vibrating the hollow fiber membrane by applying bubbles thereto), the hollow fiber membrane in the module is usually relaxed to some extent. Since the hollow fiber membranes in the adjacent modules are parallel to the fiber axis direction, entanglement may occur between the hollow fiber membranes. If the entanglement occurs, the suspended matter that adheres to the portion easily grows. Therefore, the installation interval of the hollow fiber membrane module could not be shortened beyond a certain level. In addition, since the entangled portion does not vibrate as fibers but moves as lumps during scrubbing, the cleaning effect is reduced.

Further, if the fiber axis directions of the hollow fiber membrane are all the same, the hollow fiber membrane is fixed by a fixing member, so that the most difficult part of the root portion of the so-called hollow fiber membrane is washed by scrubbing. There was a need for spacing, which set an upper limit for the installed membrane area per volume.

The object of the present invention is to provide a hollow fiber membrane module in which a hollow fiber membrane is not easily fixed and integrated even when it is used for filtering highly polluted water, and which is installed in a filtration tank or the like with high volume efficiency and used. An object of the present invention is to provide a hollow fiber membrane module assembly composed of a combination of a plurality of hollow fiber membrane modules, in which scrubbing cleaning of the module reduced by the above can be performed easily and efficiently.

[0011]

Means for Solving the Problems That is, the present invention provides a hollow fiber membrane which is arranged in a sheet form and spread, and a fixing member which fixes the end portion of the hollow fiber membrane while keeping it open.
A hollow fiber membrane module assembly comprising a plurality of hollow fiber membrane modules, each having a structural member for supporting and housing a fixing member, and having a cross section perpendicular to the hollow fiber membrane of the fixing member that is elongated and substantially rectangular. , The sheet-like material constituted by the hollow fiber membranes in each hollow fiber membrane module is substantially parallel to each other, and the fiber axes of the hollow fiber membranes in the adjacent sheet-like materials have a twist angle of about 90 °. The hollow fiber membrane module assembly is characterized in that the hollow fiber membrane module is arranged so that

[0012]

The hollow fiber membrane module assembly of the present invention will be described in more detail below with reference to the drawings.

FIG. 1 is an exploded perspective view showing an example of the hollow fiber membrane module assembly of the present invention, in which the hollow fiber membrane module group shown above and the hollow fiber membrane module group shown below are integrated. Thus, the hollow fiber membrane module assembly of the present invention is formed. That is, the lower module group is arranged and integrated at the position shown by the dotted line in the upper module group.

First, the hollow fiber membrane module 1 used in the hollow fiber membrane module assembly of the present invention will be described. In FIG. 1, the hollow fiber membrane module 1 is configured to include a structural material 2, a fixing member 3, and a hollow fiber membrane 4. In addition to these, various attachment members such as a support member, a frame, and a dispersion unit may be attached.

The structural material 2 functions as a member for supporting the entire hollow fiber membrane module, has an elongated and substantially rectangular opening, and has a filtrate chamber inside thereof. Any material may be used as long as it has mechanical strength and durability, and examples thereof include polycarbonate, polysulfone, polypropylene, acrylic resin, ABS resin, modified PPE resin, vinyl chloride resin and the like.

As shown in FIG. 1, in a hollow fiber membrane module of a type in which hollow fiber membranes are linearly arranged and both ends thereof have openings, two structural materials are used per module, and as shown in FIG. In the module of the type in which the hollow fiber membrane is bent into a U shape and used, one structural material is used. Either module can be used in the hollow fiber membrane module assembly of the present invention. A filtrate outlet is provided at one end or both ends of the structural material 2.

The opening of the structural member 2 must be such that the shape of the cross section of the fixing member, which is filled and fixed together with the hollow fiber membrane, in the section perpendicular to the hollow fiber membrane is an elongated rectangular shape. The length of the short side of this rectangle is preferably 30 mm or less, and particularly preferably 15 mm or less. That is, since the hollow fiber membranes are fixed to the string-shaped band of the fixing member, the entire hollow fiber membranes in the module are arranged in a flat sheet shape and spread. In this way, by arranging and expanding a large number of hollow fiber membranes in a sheet shape while aligning them in substantially parallel, it is possible to prevent the hollow fiber membrane bundle from being fixedly integrated into a single rod shape. Hereinafter, the sheet-shaped aggregate in which the entire hollow fiber membrane is morphologically formed is abbreviated as "sheet-shaped object". On the other hand, the length of the long side of the rectangle is not particularly limited, but if it is too short, it is not preferable because the number of hollow fiber membranes that can be arranged in one hollow fiber membrane module decreases, and if it is too long, manufacturing is difficult. Is not desirable. Usually, the length of the long side is about 100 to 2000 mm.

The fixing member 3 is filled and fixed in the openings of the structural material 2, and the end portions of a large number of hollow fiber membranes 4 are bundled and fixed while keeping the open state, and the hollow fiber membranes are also fixed. In order to function as a filtration membrane, it functions as a member that liquid-tightly separates the water to be treated from the treated water. The fixing member 3 is
It is usually formed by curing a liquid resin such as an epoxy resin, an unsaturated polyester resin or polyurethane.

As the hollow fiber membrane 4, various types can be used, for example, various types of materials such as cellulose type, polyolefin type, polyvinyl alcohol type, PMMA type and polysulfone type can be used, but polyethylene, polypropylene and the like can be used. It is preferable to use a material having high strength and elongation.
There are no particular restrictions on the pore size, porosity, film thickness, outer diameter, etc., as long as it can be used as a filtration membrane, but it is necessary to secure the membrane area per removal object or volume and the strength of the hollow fiber membrane. Considering the above, as a preferable example, the pore diameter is 0.01 to 1 μm.
m, porosity 20 to 90%, film thickness 5 to 300 μm, outer diameter 2
The range of 0 to 2000 μm can be mentioned. Also,
The pore size is 0.2 μm for the purpose of removing bacteria
The following is essential, and in the case of removing organic substances and viruses, an ultrafiltration membrane having a molecular weight cutoff of tens of thousands to hundreds of thousands may be used.

As a surface property of the hollow fiber membrane, a so-called permanent hydrophilization membrane having a hydrophilic group on the surface is desirable. As a method for producing the permanently hydrophilic film, a known method such as a method for producing a hollow fiber membrane with a hydrophilic polymer such as polyvinyl alcohol or a method for hydrophilizing the surface of a hydrophobic polymer membrane can be used. For example, as an example of the hydrophilic polymer when the hydrophilic polymer is applied to the membrane surface to make the hydrophobic hollow fiber membrane hydrophilic, saponified ethylene-vinyl acetate copolymer, polyvinylpyrrolidone and the like can be mentioned. . An example of hydrophilization of the film surface by another method is a film surface polymerization method of a hydrophilic monomer, and examples of this monomer include diacetone acrylate. Further, as another method, a method of blending a hydrophobic polymer (for example, polyolefin) with a hydrophilic polymer to form a film by spinning can be cited. Examples of the hydrophilic polymer to be used include those mentioned above. To be When the surface is a hydrophobic hollow fiber membrane, hydrophobic interaction between organic matter in the water to be treated and the surface of the hollow fiber membrane causes adsorption of organic matter on the membrane surface, which leads to blockage of the membrane surface and filtration. The life is shortened. In addition, clogging caused by adsorption is generally difficult to recover filtration performance by washing the membrane surface.
By using the permanent hydrophilization membrane, the hydrophobic interaction between the organic matter and the hollow fiber membrane surface can be reduced, and the adsorption of the organic matter can be suppressed. In addition, when scrubbing, the surface of a hydrophobic film may become dry due to bubbles, which may increase the hydrophobicity and cause a decrease in flux. Does not occur.

In order to store the hollow fiber membrane 4 as a sheet-like material in the elongated rectangular opening of the structural material 2, a hollow fiber membrane is used as a weft to form a knitted fabric (for example, Russell knitted fabric). It is preferable to use one or a laminate of several knitted fabrics.

The structural material 2 functions as a member for supporting the entire hollow fiber membrane module, has an elongated substantially rectangular opening, and has a filtrate chamber 9 therein. Any material may be used as long as it has mechanical strength and durability, and examples thereof include polycarbonate, polysulfone, polypropylene, acrylic resin, ABS resin, modified PPE resin, vinyl chloride resin and the like.

The hollow fiber membrane module assembly of the present invention comprises a plurality of hollow fiber membrane modules as described above, and as shown in FIG. The hollow fiber membrane modules are arranged such that they are substantially parallel to each other and the fiber axis directions of the hollow fiber membranes in the adjacent sheet-like materials are in a positional relationship of a twist angle of approximately 90 °. In other words, a group of two hollow fiber membrane modules in which the fiber axis direction has a twist angle of approximately 90 ° is combined and configured. Figure 3
FIG. 2 is a cross-sectional perspective view showing a state in which the hollow fiber membrane module groups of the hollow fiber membrane module assembly of FIG. 1 are combined. The direction of the fiber axis is approximately 90 for each adjacent sheet.
Even if there is slack in the arrangement of the hollow fiber membranes due to the offset, no entanglement occurs between the sheet-like materials.

In FIG. 1, as all the hollow fiber membrane modules in the assembly, those having a pair of structural materials at both ends of the sheet-like material are used, and a group of hollow fiber membrane modules shown above is used. Are arranged so that the sheet-like material faces the vertical direction and the fiber axis of the hollow fiber membrane faces the horizontal direction. On the other hand, the group of hollow fiber membrane modules shown below is arranged such that the sheet-shaped material is bent and the sheet-shaped material of the group of hollow fiber membrane modules is sandwiched between the sheet-shaped material and the sheet-shaped material. The fiber axes of the hollow fiber membranes are all oriented in the vertical direction. The reason why the structural members of the lower group of hollow fiber membrane modules are alternately arranged at the top and bottom with a step difference is to arrange the sheet-shaped materials with a narrow interval.
If the pair of structural materials of the hollow fiber membrane module are arranged so as to be placed in an up-down relationship, the structural material located below interferes with the supply of bubbles during scrubbing, and the suspended turbidity is the root of the hollow fiber membrane. It is not preferable because it easily accumulates on the part.

As described above, when the sheets are arranged in parallel with each other in the vertical direction, the bubbles rise smoothly during the scrubbing, and the bubbles are dispersed throughout the hollow fiber membrane in the assembly. Since it can be applied uniformly, washing can be performed uniformly, which is preferable.

In the assembly of the present invention, the two groups of hollow fiber membrane modules in which the fiber axis directions of the hollow fiber membranes are in a positional relationship of a twist angle of approximately 90 °, modules of different groups are adjacent to each other as much as possible. It is important that they are arranged so that the effects of the present invention can be exhibited more effectively. When one group of hollow fiber membrane modules is manufactured by stacking two Russell knits, as shown in FIG. It is a preferred embodiment to dispose the sheet-shaped material of the hollow fiber membrane 8 of another module group in which the fiber axis direction has a positional relationship of a twist angle of approximately 90 °. By interposing sheets of hollow fiber membranes of other groups, the occurrence of entanglement of hollow fiber membranes in the same module is also reduced.

The number of hollow fiber membrane modules arranged in the hollow fiber membrane module assembly of the present invention is not particularly limited as long as it is two or more. The number of hollow fiber membrane modules belonging to the group
It is preferably about 20 and more preferably about 10 to 15.

In order to maintain the positional relationship of each hollow fiber membrane module in the hollow fiber membrane module assembly of the present invention as described above, a water conduit for guiding the filtrate to be connected to the structural material can be used, or separately. You may use the support member provided, such as a support | pillar and a piano wire. Further, the air diffuser 6 used for the function recovery process of the module may be arranged at the bent portion of the sheet-like material as shown in FIG. 3 to share this role. The hollow fiber membrane module assembly can be assembled in the filtration tank, but it is preferable to use the hollow fiber membrane module assembly as an assembly assembled in advance while maintaining the above-mentioned positional relationship because it is easy to use. When the treated water outlet of each hollow fiber membrane module is connected to the water conduit through a joint, the module can be easily attached and detached.

In the hollow fiber membrane module assembly of the present invention, the structural materials of the hollow fiber membrane modules may be arranged in contact with each other, or as shown in FIG. 1, the structural materials have a constant gap. It may be arranged in this way. However, regarding the structural material located above the assembly, it is necessary to consider that bubbles supplied by scrubbing escape upward. The distance between the sheets of the hollow fiber membrane depends on the thickness of the structural material 5 of the hollow fiber membrane module used, but is usually about 10 to 50 mm and 10 to 20 mm.
Is preferred.

When the hollow fiber membrane module assembly of the present invention is used, a so-called pressure filtration method in which the hollow fiber membrane is placed in a closed container and pressurized by treating water to permeate the hollow fiber membrane can be employed. It is preferably used in a suction filtration method in which it is disposed in a sludge tank, a sedimentation tank, or the like, and the side for collecting the treated water that has permeated the hollow fiber membrane is sucked. With the suction filtration method, it is not necessary to form the tank as a can, the module assembly can be used simply by immersing it in the tank, the operating energy cost is low, and a mild operating condition is adopted for the hollow fiber membrane. Because it is done. In addition, by adopting a so-called intermittent suction operation method that stops temporary suction periodically,
It is possible to efficiently prevent the membrane surface deposit from entering the inside of the membrane surface, and it is possible to reduce the frequency of function recovery processing of the hollow fiber membrane module. Further, the method of intermittently backflowing the permeated liquid for about several seconds at a time such as when suction is stopped has a remarkable effect in preventing clogging of the hollow fiber membrane.

In the suction filtration method, the water to be treated outside the hollow fiber membrane module assembly may be stopped, but it may be agitated or the water to be treated may be placed in the direction of arrangement of the hollow fiber membranes. It is preferable that the treatment is carried out substantially vertically to improve the cleaning effect on the membrane surface of the hollow fiber membrane.

The hollow fiber membrane module assembly of the present invention is particularly suitable for filtration of highly polluted water, and specific fields of application include river water filtration, industrial water filtration, sewage treatment (sewage treatment plant). , Single or combined septic tank), solid-liquid separation and higher-order treatment, pool water filtration, seawater filtration, sterilization and sterilization filtration in the food industry.

As a method for recovering the function of the hollow fiber membrane module assembly of the present invention, a backwashing method can be simply carried out as in the case of a normal module, but a scrubbing washing method is used in which the hollow fiber membranes are always laminated with sheets. It can be efficiently implemented due to the physical form of the assembly, which maintains the installed arrangement.

[0034]

According to the hollow fiber membrane module assembly of the present invention, since the fiber axes of the hollow fiber membranes in the adjacent sheet-like objects have a twist angle of about 90 °, the adjacent sheets during scrubbing. Since the vibrating directions of the hollow fiber membranes in the material are different, the hollow fiber membranes are less likely to be entangled with the adjacent sheet material. Therefore, the space between the sheet-like materials can be made narrower than in the conventional case, and the installation area of the hollow fiber membrane per unit volume can be increased. In addition, during the scrubbing cleaning, the hollow fiber membranes in the adjacent sheet-shaped objects come into contact with each other in a state where the fiber axes are orthogonal to each other, so that the cleaning effect due to the friction between the hollow fiber membranes is exerted, and the scrubbing cleaning can be performed efficiently. It is possible to maintain high filtration efficiency for a long time in filtering highly polluted water.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a hollow fiber membrane module assembly of the present invention.

FIG. 2 is a perspective view showing another example of the hollow fiber membrane module used in the hollow fiber membrane module assembly of the present invention.

3 is a cross-sectional perspective view showing a state in which hollow fiber membrane module groups of the hollow fiber membrane module assembly of FIG. 1 are combined.

FIG. 4 is a partial schematic cross-sectional view for explaining the positional relationship of the hollow fiber membrane modules in the hollow fiber membrane module assembly of the present invention.

[Explanation of symbols]

1 Hollow fiber membrane module 2 structural materials 3 fixing members 4 hollow fiber membranes 5 Treated water outlet 6 Air diffuser 7 Russell knitting 8 Hollow fiber membranes of other modules 9 Filtrate chamber

Front Page Continuation (72) Inventor Toshio Koshida 5-17-22 Noda, Fukushima-ku, Osaka City, Osaka Prefecture S.L. (72) Inventor Tatsuro Yamamoto, 5-chome, Koiemotocho, Tokoname City, Aichi Prefecture Company Inax (72) Inventor Tadashi Matsuda 2-8-3 Kiba, Koto-ku, Tokyo Mitsubishi Rayon Engineering Co., Ltd. (72) Inventor Naoya Tanakamaru 2-3-19 Kyobashi, Chuo-ku, Tokyo Mitsubishi Rayon Co., Ltd. In-house (56) References JP-A 5-184879 (JP, A) JP-A 5-220356 (JP, A) JP-A 6-165923 (JP, A) JP-A 64-60367 (JP, A) ) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B01D 61/00-65/10 C02F 1/44 C02F 3/12

Claims (2)

(57) [Claims] 1. A hollow fiber membrane, which is arranged in a sheet form and arranged so as to be spread, a fixing member for fixing the hollow fiber membrane while keeping an end portion of the hollow fiber membrane open, and a structural material for supporting and housing the fixing member. A hollow fiber membrane module assembly comprising a plurality of hollow fiber membrane modules, each having a substantially rectangular elongated cross section perpendicular to the hollow fiber membrane of the fixing member. The hollow fiber membrane module is arranged such that the sheet-like materials formed by the membranes are substantially parallel to each other, and the fiber axes of the hollow fiber membranes in the adjacent sheet-like materials are in a positional relationship of a twist angle of about 90 °. A hollow fiber membrane module assembly, characterized in that 2. The hollow fiber membrane module has a pair of structural materials at both ends of a sheet-like material, and a group of the hollow fiber membrane modules has a sheet-like material oriented vertically. , The fiber axes of the hollow fiber membranes are arranged in a horizontal direction, and the other group of hollow fiber membrane modules are folded so that the sheet-like material sandwiches the sheet-like material of the one group of hollow fiber membrane modules. Claim 1 which is arranged as
The hollow fiber membrane module assembly described.