JP3924926B2 - Hollow fiber membrane filtration membrane module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hollow fiber membrane module for water purification . More particularly, it relates to a hollow fiber membrane module to be used for water treatment of industrial water or tap water, and in particular to Soraitomaku module in use in water treatment for tap water.
[0002]
[Prior art]
The membrane separation method is a technology that is widely used while expanding its application field because it has features such as energy saving, space saving, labor saving, and product quality improvement. Examples of membrane separation methods include reverse osmosis, ultrafiltration, microfiltration, gas separation, blood purification, and pervaporation. Moreover, there are hollow fiber membranes, flat membranes, tubular membranes, and the like in the form of separation membranes, which are properly used according to the properties and characteristics of each of the above separation objects.
[0003]
Conventionally, in the field of microfiltration, small disk filters and flat membrane pleated cartridge filters have been used for the purpose of separating and filtering relatively clear aqueous solutions with a relatively small volume of processing. In the field of ultrafiltration, flat membrane filtration devices and hollow fiber membrane modules have been used for the production of ultrapure water, food production, soft drinks, and the like.
[0004]
In recent years, research has been conducted to apply such microfiltration and ultrafiltration hollow fiber membranes to water purification processes that produce industrial water and tap water from river water and groundwater. Microfiltration and ultrafiltration technologies are beginning to be applied to such fields where raw water is used for a long time.
[0005]
A hollow fiber membrane module using a porous hollow fiber membrane can take a very large filtration area per unit volume, has a simple sealing mechanism that separates the undiluted solution to be membrane-treated from the membrane permeate, and has a high water quality. It has various advantages such as superiority and easy operation management.
[0006]
In particular, in the field of water purification process, attention has been focused on the fact that the water quality is superior to the conventional coagulation sedimentation / sand filtration method, and it is easy to automate and save labor, and is being actively introduced. Furthermore, even for tap water contaminated with pathogenic protozoa with strong resistance to chlorine sterilization such as Cryptosporidium, it has been attracting attention as a technology that can reliably remove pathogenic protozoa, and a treatment method for such raw water Recommended as.
[0007]
However, when used for such a purpose, the hollow fiber membrane module has a possibility that the hollow fiber membrane is broken and raw water is mixed into the membrane filtrate. For normal water quality evaluation items, such as turbidity, even if some hollow fiber membranes break, there is almost no risk of problems, but in the case of Cryptosporidium, it is extremely strong because of its strong infectivity. Even if a small number of hollow fiber membranes break, it may cause a problem.
[0008]
[Problems to be solved by the invention]
The object of the present invention is to solve the drawbacks of the conventional hollow fiber membrane type module, and even if the hollow fiber membrane breaks, microorganisms such as pathogenic protozoa represented by Cryptosporidium do not leak. An object of the present invention is to provide a hollow fiber membrane filtration membrane module and a method for producing water for industrial use or tap water.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises the following configurations.
That is, in the external pressure type hollow fiber membrane type filtration membrane module, a filter member made of a precision filtration membrane having a pore diameter larger than the pore diameter of the hollow fiber membrane is attached to the hollow fiber membrane opening end surface of the hollow fiber membrane potting portion for taking out membrane filtrate water. The hollow fiber membrane filtrate is configured to be filtered by the filter member, and has the following preferred embodiment.
(1) Precision filtration consisting membrane filter member Organization for close contact with the potting portion hollow fiber membranes open end face and a precision filtration membrane in a liquid tight manner, the pressing member to prevent deformation of the microfiltration membrane and the microfiltration membrane, and, the filter member and the membrane filtrate water collecting module cap and liquid-tight in close contact to Organization or Ranaru a.
( 2 ) The filter member is made of a polymer microfiltration membrane .
(3) filter member, RaNaruko and or sintered metal microfiltration membranes.
[0010]
In the present invention, the water purification process for the preparation of industrial water or tap water, the supplied raw water to one of the hollow fiber membrane type modules, passes through the hollow fiber membrane was further transmitted through the full Iruta member The present invention provides a water purification method characterized by taking out water.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show an example of the hollow fiber membrane module of the present invention. Figure 4-6 is a diagram of the potting portion of a cross section of the hollow fiber membrane filtration membrane module schematically showing the present invention fitted with a filter member made of a microfiltration membrane, a hollow fiber membrane potting portion hollow to take out the membrane filtration water A filter member made of a microfiltration membrane having a pore size larger than the pore size of the hollow fiber membrane is attached to the end surface of the yarn membrane opening, and it is configured to filter the hollow fiber membrane filtrate with the filter member. .
[0012]
1, a hollow fiber membrane 2 obtained by bundling a U-shape, and inserted into the outer cylinder 1 of the membrane module, the hollow fiber membrane bundle is adhered and fixed by the potting material 3 on the outer tube ends, the hollow fibers An example of a hollow fiber membrane filtration membrane module having a structure in which a filter cap 5 is incorporated and a module cap 8 for collecting membrane filtration water is attached in contact with the opening end face 4 of the membrane is shown. An example of the method of using the hollow fiber membrane type filtration membrane module shown in FIG. 1 is as follows. That is, the raw water containing suspended solid matter is introduced into the raw water supply nozzle 10B Karamaku the module, are filtered through the membrane from the outside of the hollow fiber membrane inside. The filtered membrane filtrate flows through the hollow portion of the hollow fiber membrane and is taken out from the membrane filtrate outlet nozzle 6 of the membrane module through the water collection portion 7 from the opening end face 4. Turbidity in the raw water is trapped and deposited on the outer surface of the hollow fiber membrane.
Filtration resistance increases cake layer of suspended substances deposited on the outer surface of the hollow fiber membrane becomes thick, Do differential pressure required for filtration reaches a predetermined value mules, by stopping the supply of raw water, required Accordingly, a certain amount of filtered water is caused to flow backward from the nozzle 6 for back pressure washing, and air is introduced from the nozzle 11 so that the air bubbles and the upward flow of water generated as the bubbles rise, the hollow fiber. The cake layer consisting of turbid components is physically removed by shaking the membrane.
The membrane filtrate passes through the filter member 5 made of a precision filtration membrane having a pore diameter larger than the pore diameter of the hollow fiber membrane placed at the water collection portion from the opening of the hollow fiber membrane and passes through the membrane module. It is taken out from the outlet nozzle 6 to the outside of the membrane module.
[0013]
FIG. 2 shows that the hollow fiber membrane bundle 12 is inserted into the outer cylinder 21 of the membrane module, and the hollow fiber membrane bundle is bonded and fixed at both ends of the outer cylinder with the potting materials 13 and 13 ′. An example of a hollow fiber membrane filtration membrane module having a structure in which filter caps 15 and 15 'are incorporated and module caps 18 and 18' for collecting membrane filtration water are attached in contact with the end faces 14 and 14 '. Yes. An example of how to use the hollow fiber membrane type filtration membrane module shown in FIG. 2 is as follows. That is, the raw water containing suspended solid matter is introduced into the raw water supply nozzle 20 and / or 20 'Karamaku the module, are filtered from the outside of the hollow fiber membrane passes through the membrane inside. The filtered membrane permeate flows in the hollow part of the hollow fiber membrane and passes from the opening end face 14 and / or 14 'through the water collecting part 16 and / or 16' to the permeate outlet nozzles 17 and / or 17 of the membrane module. 'Taken out'. The raw water is supplied by providing a plurality of passages through the potting part in the potting part to which the hollow fiber membrane bundle located below the hollow fiber membrane filtration membrane module is bonded and fixed, and passing through the potting part. A structure may be used in which the material is supplied as uniformly as possible. Turbidity in the raw water is trapped and deposited on the outer surface of the hollow fiber membrane.
When the turbid cake layer deposited on the outer surface of the hollow fiber membrane becomes thicker and the filtration resistance increases, and the differential pressure required for filtration reaches a predetermined value, the supply of raw water is stopped, and if necessary Then, a certain amount of filtered water is reversely flown from the nozzles 17 and / or 17 ′ and back-pressure washed, and air is further introduced from the nozzles 20 ′ to oscillate the hollow fiber membrane by the upward flow of air bubbles and bubbles. The cake layer consisting of suspended matter is physically removed. In the case of a hollow fiber membrane filtration membrane module having a structure with a plurality of raw water supply passages penetrating through the potting portion, the pressurized air is discharged from the raw water supply passages, and bubbles and bubbles rise. The hollow fiber membrane is rocked by the generated upward flow of water to physically remove the cake layer composed of turbid components.
Membrane filtration water passes through the filter member 15 and / or 15 'consists of hollow fiber membranes greater microfiltration membrane from the opening of the pore size than the pore size of the hollow fiber membranes placed on the outlet was at the collecting portion of the From the permeate outlet nozzle 17 and / or 17 ′ of the membrane module, it is taken out of the membrane module.
FIG. 3 shows a membrane module having the same configuration as that of FIG. 2, but shows an example of a closed end portion in which all of the hollow fiber membranes at one end portion of the membrane module are sealed. Reference numeral 32 denotes a closed end portion, and 33 denotes a central pipe provided with a plurality of small holes for diffusing air for physical cleaning. Reference numeral 34 denotes an introduction hole for physical cleaning air.
[0014]
The filtering material constituting the filter member, precision filtration membrane Ru is used. Construction of full Iruta member is of a configuration shown in FIG. 4, or 5, or even may be either a filter member such as a combination of a plurality of leaf disc filter shown in FIG.
FIG. 4 shows a pressing member 42 and a packing 39 for placing a packing 39-1 on the opening end face 40 of the hollow fiber membrane bundle 37 to bring it into close contact with the filtration material 41 and preventing the filtration material and deformation of the filtration material due to filtration pressure. -2 in close contact, and the water collecting cap of the membrane module is in close contact via the pressing member 42 and packing 39-3. The configuration shown in FIG. 5 shows an example in which a filter member having a structure in which a filtering material 54 and a pressing member 53 are integrally molded is incorporated. Reference numeral 51 denotes a flange that integrally fixes the filtration material 54 and the pressing member 53. The filtration material 54 and the pressing member 53 are brought into liquid-tight contact with each other, and the outer edge of the opening end surface 52 of the hollow fiber membrane bundle 48 and The membrane module cap 57 and the filter member are brought into liquid tight contact. The filtering material 41 or 54 may be processed into a pleated shape, and it is rather preferable that the effective membrane area can be increased if it is liquid-tightly sealed.
FIG. 6 shows a filter member in which a plurality of filter members in which a filtering material is processed into a leaf disk filter shape are fixed to a central pipe. Reference numeral 64 denotes a leaf disc filter, 65 denotes a spacer between the leaf disc filters, and 66 denotes an O-ring for fixing the filter member and the membrane module cap in a liquid-tight manner. The filtered water is taken out from the central water collecting pipe 67.
[0015]
Microfiltration membrane constituting the filter member is a great microfiltration membrane having a pore size than the pore size of the hollow fiber membranes, polymeric materials, metallic film material, a ceramic membrane material, such as glass film material, a predetermined filtering as filtering material as long as it has the accuracy and transmission speed and durability, it can be used even microfiltration membrane of any material.
[0016]
The polymer materials constituting the microfiltration membrane include polyethylene, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, polytetrafluoroethylene, polyvinyl fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, tetra Fluoroethylene-perfluoroalkyl vinyl ether copolymer, chlorotrifluoroethylene-ethylene copolymer, polyvinylidene fluoride, polysulfone, polyethersulfone and the like can be used. Furthermore, it is also possible to use filter media made of a sintered product of these polymers.
[0017]
Sintered metal microfiltration membranes with a metal microfiltration membranes good Mashiku be used. For example, a sintered metal fiber-made microfiltration membrane sintered fine particles, such as SUS304 or SUS316 are particularly preferably used.
[0018]
As ceramic and glass filter materials, those sintered porous bodies can be used.
[0019]
As the pore size of such a filtration material, a filtration material having a pore size in the range of 0.03 μm to 4.0 μm, preferably 0.05 μm to 2.0 μm, more preferably 0.1 μm to 1.0 μm is used. Is done. One of the conditions for determining the pore size is to remove the turbid matter mixed in when the hollow fiber membrane breaks or the specific microorganisms that cannot be disinfected or disinfected by chlorination etc. It is possible to ensure sex. The other is that the filtration differential pressure due to the membrane module can be used without significantly increasing over a long period by mounting the filter member. That is, a filter member made of a filtration material having a water permeability of 1000 L / (m ² · h) / (100 kPa) or more, preferably 10,000 L / (m ² · h) / (100 kPa) or more is used. The higher the upper limit of the water permeability, the smaller the pressure loss due to the filter member, but in reality there is a trade-off relationship with the filtration accuracy of the filtration material. (M ² · h) / (100 kPa) or less, about 10000 L / (m ² · h) / (100 kPa) for more preferable filtration accuracy. As a result of examining the filtration material and filtration accuracy from the above viewpoint, the above pore diameter range can be preferably used.
[0020]
【Example】
Hereinafter, the configuration and effects of the present invention will be described in more detail with reference to examples.
[0021]
The effect of the present invention was confirmed by the following method. Since experiments using Cryptosporidium are very difficult, it is usually said that the evaluation should be based on the removability of predetermined particles. There are two types of Cryptosporidium, which usually cause problems with human infection, and have an ellipsoidal shape. Small (4.5-5.4)-(4.2-5.0) μm, and large types (6.6-7.9)-(5.3-6.5) μm are reported, with 4-6 μm removal of polystyrene beads. It can be evaluated. However, it is impractical to evaluate the removal rate of 10 ⁻⁶ to 10 ^{−7 with} a polystyrene bead for a practical scale membrane module because it requires a very large amount of test water. The fine particles to be measured were measured and evaluated. In addition, for the conventional agglomerated sedimentation sand filtration method, the turbidity is controlled by reference to Cryptosporidium because the turbidity is controlled to 0.1 or less.
[0022]
Example 1 and Comparative Example 1
A bundle of hollow fiber membranes composed of 3,500 polyacrylonitrile porous hollow fiber membranes having an outer diameter of 680 μm, an inner diameter of 400 μm, and an average pore diameter of 0.01 μm is bundled in a U shape, and both ends thereof are hard vinyl chloride having an outer diameter of 110 mm and an inner diameter of 104 mm. After inserting into the pipe housing and fixing one end portion with an adhesive, a part of the adhesive fixing portion was cut to open the inside of the hollow fiber membrane. And, in the structure as shown in FIG. 5, using a filter material made of SUS304 sintered stainless steel fiber and pleated with a filtration accuracy of 1.0 μm and a disk filter member formed integrally with a pressing member, A hollow fiber membrane filtration membrane module was manufactured.
[0023]
The hollow fiber filtration membrane modules hollow fiber membrane Le cut 300 present in the potting portion near to the test membrane module of the present invention (Example 1). For the other one, 300 hollow fiber membranes were similarly cut without attaching a filter member and used for a comparative test (Comparative Example 1) .
[0024]
Using these hollow fiber membrane modules, raw water containing 8.2 × 10 ⁸ particles / ml of turbidity of 6.9 and diameter of 4 μm or more was filtered at a flow rate of 8.3 l / min. Turbidity and fine particles in water were measured. As a result, in the membrane module in which 300 hollow fiber membranes were cut without attaching the filter member, particles having a turbidity of permeated water of 1.4 and a diameter of 4 μm or more were detected at 1.6 × 10 ⁸ particles / ml. (Comparative Example 1) On the other hand, in a membrane module equipped with a sintered stainless steel fiber filter member, the membrane module has a turbidity of 0.02 and particles having a diameter of 4 μm or more are 10 particles / ml or less, and the hollow fiber membrane is not cut. The particle which leaked from the hollow fiber cutting part was substantially removed with the filter member (Example 1) .
[0025]
The filtration differential pressure of the membrane module is 50 kPa for the membrane module equipped with the filter member, and 25 kPa for the membrane module not equipped with the filter member. did it.
[0026]
Example 2 and Comparative Example 2
A hollow fiber membrane bundle of about 1000 mm in length composed of 7400 polyacrylonitrile porous hollow fiber membranes having an outer diameter of 680 μm, an inner diameter of 400 μm, and an average pore diameter of 0.01 μm is inserted into an outer tube made of polyvinyl chloride, and both ends thereof are bonded and fixed. Then, a hollow fiber type filtration membrane module as shown in FIG. 2 having a shape in which the end portion was cut and the inside of the hollow fiber membrane was opened at both end portions was manufactured. One membrane module cuts 10 hollow fiber membranes in the vicinity of the nozzle 20, and a disk filter member made by pleating a sintered stainless steel fiber having a filtration accuracy of 0.6 μm is attached to both end faces of the membrane module. (Example 2) . In other membrane modules, ten hollow fiber membranes were cut in the vicinity of the nozzle 20 and no filter member made of sintered stainless steel fibers was attached (Comparative Example 2) .
[0027]
In the same manner as in Example 1, the turbidity and the number of particles of the permeated water of the above two membrane modules were compared using raw water containing 6.2 × 10 ⁸ particles / ml having a turbidity of 5.2, 4 μm or more. As a result, in the membrane module not equipped with the filter member, the turbidity of the permeated water was 0.035, and particles having a diameter of 4 μm or more were detected at 4.0 × 10 ⁶ particles / ml (Comparative Example 2) . In contrast, in a membrane module equipped with a filter member made of sintered stainless steel fiber, the turbidity is 0.01 or less, the number of particles of 4 μm or more is 10 particles / ml or less, and the membrane does not cut the hollow fiber membrane. The result was no different from the module. The difference in filtration differential pressure between them was 27 kPa or less, and there was no difference in the rate of increase in differential pressure, and no operational problems were observed (Example 2) .
[0028]
Example 3 and Comparative Example 3
In the same manner as in Example 1, a hollow fiber membrane bundle composed of 3500 polyacrylonitrile porous hollow fiber membranes was bundled in a U shape, inserted into a housing of a hard vinyl chloride pipe, and one end portion was fixed with an adhesive, A membrane module having a shape in which a part of the adhesive fixing portion was cut to open the hollow fiber membrane was manufactured. One membrane module was cut about 10 near the potting portion of the hollow fiber membrane, and a filter member composed of three leaf disk filters of sintered stainless steel fibers as shown in FIG. 6 was mounted (implementation). Example 3) . The filtration accuracy of the filter was 0.3 μm. Other membrane modules were prepared by cutting 10 hollow fiber membranes and not attaching a filter member (Comparative Example 3 ).
[0029]
In the same manner as in Example 2, the raw water having a turbidity of 5.2 was supplied at 4.2 ml / min and the whole amount was filtered, and the turbidity and the number of particles of the permeated water were measured. The turbidity of the permeated water of the membrane module not equipped with a filter member was 0.035, and particles having a diameter of 4 μm or more were detected at 4.0 × 10 ⁶ particles / ml (Comparative Example 3) . On the other hand, the membrane module equipped with the filter member has a turbidity of 0.01 or less, and the number of particles of 4 μm or more is several particles / ml or less, which is not different from the membrane module that does not cut the hollow fiber membrane. (Example 3) . In addition, both filtration differential pressure | voltages were 60 kPa, there was no difference in the increase rate of differential pressure | voltage, and it was able to drive | operate without a problem.
[0030]
【The invention's effect】
According to the present invention as described above, in the hollow fiber membrane filtration membrane module used in the fields such as water water treatment processes, even broken by any chance hollow fiber membrane, to chlorination, such as Cryptosporidium Porijiumu resistant Te contaminants, including pathogenic original insects can be reliably removed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of the entire structure of an example of a hollow fiber type filtration membrane module. FIG. 2 is a cross-sectional view of the entire structure of an example of a hollow fiber type filtration membrane module. Cross-sectional view of the overall structure of the example [Fig. 4] Cross-sectional view of the filter member mounting portion of the hollow fiber type filtration membrane module [Fig. 5] Cross-sectional view of the filter member mounting portion of the hollow fiber type filtration membrane module [Fig. Cross-sectional view of the filter member mounting part of the filtration membrane module [Explanation of symbols]
1: Hollow fiber filtration membrane module outer cylinder 2: Hollow fiber membrane 3: Adhesive fixing part (potting part)
4: Hollow fiber membrane potting part Hollow fiber membrane opening end face 5: Filter member 6: Membrane filtrate outlet 7: Membrane filtrate collection part 8: Membrane filtrate collection module cap 9: Packing 10A: Physical cleaning air release Nozzle 10B: Raw water supply nozzle 11: Physical cleaning air inlet 12: Hollow fiber membrane 13: Adhesive fixing part (potting part)
14: Hollow fiber membrane potting part Hollow fiber membrane opening end face 15: Filter member 16: Membrane filtrate collecting part 17: Membrane filtrate outlet 18: Membrane filtrate collection module cap 19: Packing 20: Nozzle 21: Hollow Thread-type filtration membrane module outer cylinder 22: hollow fiber membrane 23: adhesive fixing part (potting part)
24: Hollow fiber membrane potting part Hollow fiber membrane opening end face 25: Filter member 26: Membrane filtrate collection part 27: Membrane filtrate collection port 28: Membrane filtrate collection module cap 29: Packing 30 and 30 ': Nozzle 31: Hollow fiber type filtration membrane module outer cylinder 32: Closed end 33: Center pipe 34 with physical cleaning air blowing hole 34: Physical cleaning air introduction hole 35: Hollow fiber type filtration membrane module outer cylinder 36 Nozzle 37: Hollow fiber Film 38: Adhesive fixing part (potting part)
39-1: Packing 39-2: Packing 39-3: Packing 40: Hollow fiber membrane potting part Hollow fiber membrane opening end face 41: Filtration material 42: Holding member 43: Membrane filtrate collecting part 44: Membrane filtrate extraction port 45: Module cap for membrane filtration water collection 46: Hollow fiber filtration membrane module outer cylinder 47: Nozzle 48: Hollow fiber membrane 49: Adhesive fixing part (potting part)
50-1: Packing 50-2: Packing 51: Flange 52: Hollow fiber membrane potting part Hollow fiber membrane opening end face 53: Holding member 54: Filtration material 55: Membrane filtrate outlet 56: Membrane filtrate collection part 57: Membrane filtration water collection module cap 58: hollow fiber type filtration membrane module outer cylinder 59: nozzle 60: hollow fiber membrane 61: adhesive fixing part (potting part)
62: O-ring 63: Hollow fiber membrane potting part hollow fiber membrane opening end face 64: Leaf disk filter 65: Leaf disk filter spacer 66: O-ring 67: Leaf disk filter fixing / water collecting center pipe 68: Membrane filtration Water cap module cap

Claims (5)

In the external pressure type hollow fiber membrane type filtration membrane module, a hollow fiber membrane potting part for taking out membrane filtration water is fitted with a filter member made of a precision filtration membrane having a pore diameter larger than the hollow fiber membrane pore diameter at the hollow fiber membrane opening end face. the hollow fiber membrane filtration membrane module fiber membrane filtrate is characterized by being configured to be filtered by the filter member. Microfiltration consisting membrane filter member Organization for close contact with the potting portion hollow fiber membranes open end face and a precision filtration membrane in a liquid tight manner, the pressing member to prevent deformation of the microfiltration membrane and the microfiltration membrane, and a filter member the hollow fiber membrane filtration membrane module according to claim 1, wherein the liquid-tight in close contact to Organization or Ranaru a membrane filtrate water collecting module cap with. The hollow fiber membrane filtration membrane module according to claim 1 or 2, wherein the filter member is made of a polymer microfiltration membrane. Filter member, a hollow fiber membrane filtration membrane module according to claim 1 or 2, characterized that you made of sintered metal microfiltration membranes. In water purification process for the preparation of industrial water or tap water, supplying raw water to the hollow fiber membrane type modules according to any one of claims 1 to 4, passes through the hollow fiber membrane was further passed through the filter member Water A water purification method characterized by taking out water .

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