JP6910889B2 - Filtration membrane module and its manufacturing method and installation method of filtration membrane module - Google Patents

Description

The present invention relates to a filtration membrane module suitable as a final filter for removing fine particles in water to be treated in an ultrapure water production process, a method for producing the same, and a method for installing the filtration membrane module.

In the line that manufactures ultrapure water used in the manufacture of electronic and electrical parts such as semiconductors and display elements, ultrapure water manufactured using microfiltration membranes, ion exchange resins, and reverse osmosis filtration membranes is supplied to use points. A filtration membrane module is used as a final filter for removing fine particles from ultrapure water immediately before the filtration. Since the filtration membrane module for this purpose has the advantage that the filtration flow rate per module can be increased, an external pressure filtration type hollow fiber membrane module that supplies raw water to the outside of the hollow fiber membrane to filter is mainly used. ing.

The properties required for the filtration membrane module for this application are the water quality as ultrapure water in a short time after the start of use, that is, the number of fine particles in the filtered water, the conductivity of the filtered water, and TOC (Total).
Organic Carbon) etc. are required to reach the required level. Therefore, in general, in the filtration membrane module for this application, a cleaning process for reducing fine particle dust generation from the filter and elution of ionic components and organic substances is provided at the end of the product manufacturing process until the product is in a clean state. It is shipped in a cleaned state.

On the other hand, in order to maintain the filtration performance of the filtration membrane module and suppress the growth of microorganisms in the product, it is necessary to store the filtration membrane module in a wet state using a preservative solution having a bactericidal and bacteriostatic effect after production. In a general membrane module, an aqueous solution of glycerin, an aqueous solution of alcohol, an aqueous solution of sodium hypochlorite, or the like is used as a preservation solution (see, for example, Patent Document 1).
However, as described above, the filtration membrane module used in the ultrapure water production line is required to satisfy the water quality as ultrapure water in a short time from the start of use, so organic substances such as glycerin and alcohol, sodium and the like are used. When a preservative solution containing a metal ion component is used, there is a problem that it takes time to clean the solution. Therefore, as the preservation solution for this purpose, a formaldehyde aqueous solution that suppresses the growth of microorganisms even at a low concentration, and a hydrogen peroxide aqueous solution that has a bactericidal effect without leaving organic substances and ionic components have been used.

Japanese Unexamined Patent Publication No. 6-296838

However, when an aqueous formaldehyde solution is used, although the growth of microorganisms can be suppressed at a low concentration of less than 1%, it affects the reduction of TOC. On the other hand, hydrogen peroxide solution suppresses the growth of microorganisms and does not affect TOC, but since hydrogen peroxide has a strong oxidizing power, a polymer membrane generally used as a material for filtration membranes for this application is used. It may be deteriorated little by little, and the separation performance of the film may be deteriorated or broken.

An object of the present invention is to solve the above problems, to maintain the filtration performance of the filtration membrane, suppress the growth of microorganisms, and manufacture a filtration membrane module having no influence on the water quality after the start of use. It is an object of the present invention to provide a method as well as a method for installing a filtration membrane module.

The present inventors have conducted extensive research and verification in order to satisfy the above-mentioned various requirements. As a result, it was confirmed that all the requirements were satisfied by enclosing water in a state of being sterilized at a high temperature as the preservation solution, and a manufacturing method thereof was found and the present invention was conceived.

That is, the filtration membrane module of the present invention maintains the filtration performance of the filtration membrane in the case in the filtration membrane module including the filtration membrane used for filtering the liquid and the case in which the filtration membrane is housed. It is characterized in that it is filled with sterilized pure water as a preservative solution for this purpose.

Further, in the filtration membrane module of the present invention, the content of organic matter in the preservation liquid is preferably 5 ppm or more and less than 50 ppm as TOC (Total Organic Carbon).

Further, in the filtration membrane module of the present invention, the concentration of metal ions contained in the preservation solution is preferably 10 ppb or more and less than 100 ppb.

Further, in the filtration membrane module of the present invention, the concentration of chloride ions contained in the preservation solution is preferably 25 ppb or more and less than 250 ppb.

The method for manufacturing a filtration membrane module of the present invention is a filtration membrane module including a filtration membrane used for filtering a liquid and a case in which the filtration membrane is housed, and the filtration performance of the filtration membrane is contained in the case. This is a method for manufacturing a filtration membrane module filled with sterilized pure water as a preservative solution for holding the membrane, and the pure water sterilized by filtration is sealed in a case containing the filtration membrane. The case characterized in that the pure water is sealed is heat-treated at 80 ° C. or higher and lower than 100 ° C. to sterilize the pure water in the filtration membrane module to obtain a preservation solution.

Further, in the method for manufacturing the filtration membrane module of the present invention, in the step of heat-treating the case filled with pure water, in order to reduce the pressure increase due to the thermal expansion of the sealed pure water, the raw water side of the filtration membrane module is used. It is preferable to provide a pressure buffer mechanism in the water.

Further, in the method for manufacturing the filtration membrane module of the present invention, in the step of heat-treating the case filled with pure water, the volume expansion due to the heat of the sealed pure water is absorbed, so that the volume is on the raw water side of the filtration membrane module. It is preferable to provide an expansion absorption mechanism.

Further, in the method for producing a filtration membrane module of the present invention, the pure water sterilized by filtration is water filtered by an ultrafiltration membrane or a reverse osmosis membrane, and fine particles of 50 nm or more contained in the pure water. Is preferably 10 pieces / L or more and 200 pieces / L or less.

Further, in the method for producing a filtration membrane module of the present invention, the content of organic substances in pure water is preferably 5 ppm or more and less than 50 ppm as TOC (Total Organic Carbon).

Further, in the method for producing a filtration membrane module of the present invention, the concentration of metal ions contained in pure water is preferably 10 ppb or more and less than 100 ppb.

Further, in the method for producing a filtration membrane module of the present invention, the concentration of chloride ions contained in pure water is preferably 25 ppb or more and less than 250 ppb.

In addition, in the process of heat-treating the case filled with pure water, the thermal expansion of the sealed pure water

In order to reduce the pressure rise due to the filtration membrane module, a pressure buffer mechanism is provided on the raw water side of the filtration membrane module, and in order to absorb the volume expansion due to the heat of the enclosed pure water, a volume expansion absorption mechanism is provided on the raw water side of the filtration membrane module. The filtration side of the filtration membrane module is preferably sealed.

Further, in the method for manufacturing a filter membrane module of the present invention, the filter membrane module is a hollow fiber membrane module in which a hollow fiber membrane is housed as a filter membrane in a case, and is a filtration side communicating with a hollow portion of the hollow fiber membrane. It is possible to have a port and a raw water side port communicating with the outside of the hollow fiber membrane, and in the step of heat-treating a case filled with pure water, the raw water side port is provided with a volume expansion absorption mechanism and pressure buffered. The mechanism is provided with the sealing member contained in the pressure buffering mechanism, and the filtration side port is sealed, and after the heat treatment step, the volume expansion absorption mechanism is replaced with the sealing member in the pressure buffering mechanism, and then It is preferable to remove the pressure buffer mechanism and the volume expansion absorption mechanism.

Further, in the method for manufacturing a filter membrane module of the present invention, the filter membrane module is a hollow yarn membrane module in which a hollow yarn membrane is housed as a filter membrane in a case, and is a filtration side communicating with a hollow portion of the hollow yarn membrane. It is possible to have a port and a raw water side port communicating with the outside of the hollow filament film, and in the step of heat-treating a case filled with pure water, the raw water side port is provided with a volume expansion absorption mechanism and its volume. The expansion and absorption mechanism is provided with a pressure buffer mechanism that allows gas to permeate and does not allow bacterial cells to permeate, and a gas inflow prevention member that prevents outside air from flowing into the raw water side port is installed in the gas inflow member. It was provided with the sealing member contained, and the filtration side port was sealed, and after the heat treatment step, the volume expansion absorption mechanism was replaced with the sealing member in the gas inflow prevention member, and then the pressure buffering mechanism was provided. It is preferable to remove the volume expansion absorption mechanism and the gas inflow prevention member.

In the method of installing the filtration membrane module of the present invention, in the method of attaching the above-mentioned filtration membrane module to the piping of the water treatment device, the sealing member that seals the filtration side port and the raw water side port of the filtration membrane module is removed for filtration. It is characterized in that the pure water sealed in the membrane module is discarded in addition to the piping of the water treatment device, and then the piping of the water treatment device is attached.

According to the filtration membrane module of the present invention, sterilized pure water is sealed as a preservative solution for the filtration membrane module to maintain the filtration performance, so that microorganisms in the module can be maintained while maintaining the filtration performance of the membrane. Can suppress the growth of. That is, the filtration module can be stored for a long period of time without using chemicals, and the cleaning time at the start of use can be significantly reduced.

Further, in the above-mentioned filtration membrane module of the present invention, when the organic matter content in the preservation liquid is 5 ppm or more and less than 50 ppm as the TOC, the organic matter at the start of use can be obtained by using water having a small amount of organic matter components in this way. Cleaning time can be significantly reduced.

Further, when the metal ion contained in the preservation solution is set to 10 ppb or more and less than 100 ppb, the cleaning time of the metal component at the start of use can be significantly reduced.

Further, when the chloride ion contained in the preservation solution is 25 ppb or more and less than 250 ppb, sufficient bactericidal property can be obtained without applying an excessive temperature by containing a trace amount of chloride ion in this way. ..

According to the method for producing a filtration membrane module of the present invention, pure water sterilized by filtration is sealed in a case, and the case containing the pure water is heat-treated at 80 ° C. or higher and lower than 100 ° C. Since the pure water in the filtration membrane module is sterilized and used as a preservation solution, it is possible to suppress the growth of microorganisms in the module while maintaining the filtration performance of the membrane.

Further, in the step of heat-treating the case filled with pure water, in order to reduce the pressure increase due to the thermal expansion of the sealed pure water, if a pressure buffer mechanism is provided on the raw water side of the filtration membrane module, it is heated. It is possible to prevent the case and the hollow fiber membrane from being damaged due to the pressure inside the filtration module rising due to the expansion of water. Further, when the filtration side is completely sealed, contamination from the outside can be prevented.

In addition, in the step of heat-treating the case filled with pure water, in order to absorb the volume expansion due to the heat of the sealed pure water, if a volume expansion absorption mechanism is provided on the raw water side of the filtration membrane module, By absorbing the volume expansion during heat treatment and then shrinking the expansion by cooling, it is possible to re-inflow into the module from the raw water side of the filtration membrane module, and the inside of the filtration module can be filled. It will be possible.

Sectional drawing which shows the structure of the hollow fiber membrane module using one Embodiment of the filtration membrane module of this invention. An exploded perspective view of the hollow fiber membrane module The figure which shows the specific example of a pressure buffer mechanism and a volume expansion absorption mechanism. The figure which shows the other example of a pressure buffer mechanism and a volume expansion absorption mechanism. The figure which shows the detailed structure of each part of the filtration apparatus using the hollow fiber membrane module shown in FIG.

Hereinafter, a hollow fiber membrane module using one embodiment of the filtration membrane module of the present invention will be described with reference to the drawings.

The hollow fiber membrane module of the present embodiment can be used in a filtration device for producing ultrapure water. The hollow fiber membrane module of the present embodiment can be used for external pressure filtration performed immediately before supplying ultrapure water produced using a microfiltration membrane, an ion exchange resin, or a reverse osmosis filtration membrane to a use point. It can take on the function of removing fine particles as a final filter. Further, the hollow fiber membrane module is required to have high filtration performance in order to make the equipment compact, but the hollow fiber membrane module of the present embodiment can increase the filtration flow rate per unit volume. It can be a membrane module.

FIG. 1 is a cross-sectional view showing a schematic configuration of the hollow fiber membrane module 1 of the present embodiment. Further, FIG. 2 is an exploded perspective view of the hollow fiber membrane module 1 shown in FIG.

As shown in FIG. 1, the hollow fiber membrane module 1 of the present embodiment includes a hollow fiber membrane bundle 3 in which a plurality of hollow fiber membranes 3a are bundled, and a tubular case 5 for accommodating the hollow fiber membrane bundle 3. Is provided.

The openings at both ends of the case 5 are provided with caps 10 and 11 for connecting pipes in which pipe lines 10a and 11a to which pipes are connected are formed. It is fixedly attached to. The nut 13 is screwed into the male screws formed on the side surfaces of both ends of the case 5, and by tightening the nut 13, the O-rings 12 arranged in the grooves of the caps 10 and 11 allow the casing ends and the caps 10 and 11 to be connected. The space is sealed.

Further, upper nozzles 5a and lower nozzles 5b through which fluid flows are formed at both ends of the case 5, respectively. The upper nozzle 5a and the lower nozzle 5b are provided so as to project in a direction orthogonal to the longitudinal direction of the case 5.

On both end faces of the hollow fiber membrane bundle 3, each hollow fiber membrane 3a is open, and the hollow fiber membranes 3a are bonded to each other by a potting material to form an adhesive portion 14.

In external pressure filtration, for example, a liquid flows in from the lower nozzle 5b, and the liquid permeates from the outer surface of each hollow fiber membrane 3a between the adhesive portions 14 at both ends and passes through the hollow portion of each hollow fiber membrane 3a. The liquid is discharged from the conduits 10a and 11a of the caps 10 and 11.

As the hollow fiber membrane 3a, a microfiltration membrane, an ultrafiltration membrane, or the like can be used. The material of the hollow thread film is not particularly limited, and polysulfone, polyethersulfone, polyacrylonitrile, polyimide, polyetherimide, polyamide, polyetherketone, polyetheretherketone, polyethylene, polypropylene, poly (4-methylpentene), and ethylene. -Vinyl alcohol copolymer, cellulose, cellulose acetate, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene and the like can be mentioned, and composite materials thereof can also be used.

The inner diameter of the hollow fiber membrane 3a is 50 μm to 3000 μm, preferably 500 μm to 2000 μm. When the inner diameter is small, the pressure loss becomes large and the filtration is adversely affected. Therefore, the inner diameter of the hollow fiber membrane 3a is preferably 50 μm or more. Further, when the inner diameter is increased, it becomes difficult to maintain the shape of the film during spinning, so the diameter is preferably 3000 μm or less.

As the potting material, a polymer material such as an epoxy resin, a vinyl ester resin, a urethane resin, an unsaturated polyester resin, an olefin polymer, a silicone resin, or a fluorine-containing resin is preferable, and any of these polymer materials may be used. A plurality of polymer materials may be used in combination.

In the ultrapure water production process, the constituent members are required to have heat resistance to hot water and low elution. Therefore, as the material of the hollow fiber membrane 3a and the case 5, it is preferable that the material has less polysulfone elution. For the same reason, it is preferable to use an epoxy resin as the potting material.

Further, in the hollow fiber membrane module 1 of the present embodiment, sterilized pure water is used as the preservation solution. The storage liquid is a liquid for maintaining the filtration performance of the hollow fiber membrane 3a, and is a storage portion 5c, caps 10, 11 and an adhesive portion 14 formed between the adhesive portions 14 at both ends in the case 5. It is a liquid that fills the space between the hollow fiber membrane 3a and the hollow portion and the porous portion of the hollow fiber membrane 3a.

Here, the pure water in the present invention means water having an ionic component reduced, an electric conductivity of water of 1 μS / cm or less, and further filtered by a reverse osmosis membrane or an ultrafiltration membrane.

Further, in the hollow fiber membrane module 1 of the present embodiment, the organic matter content in the preservation liquid is preferably 1 ppm or more and less than 50 ppm as TOC (Total Organic Carbon). When the TOC is 1 ppm or more, the organic substances in the pure water are preferentially oxidized during the heat sterilization of pure water described later, so that the oxidative deterioration of the hollow fiber membrane 3a due to heating can be suppressed. The TOC is more preferably 5 ppm or more.

Further, if it is less than 50 ppm, the concentration of organic substances in the storage liquid at the start of use of the hollow fiber membrane module 1 can be quickly reduced, and even if the bacteria are not completely killed by heat sterilization, the carbon source can be used. Since it can be reduced, it is possible to suppress the growth of bacteria.

Further, in the hollow fiber membrane module 1 of the present embodiment, the concentration of metal ions contained in the preservation solution is preferably 10 ppb or more and less than 100 ppb. In the ultrapure water production process, contamination of metal ions that adversely affect semiconductor production should be avoided, and the smaller the content, the better. On the other hand, when considering sterilization, it is known that metal ions exhibit a bactericidal action, and it is possible to improve the sterilizing action by heating by containing metal ions within a range that does not adversely affect semiconductor manufacturing.

Similarly, in the hollow fiber membrane module 1 of the present embodiment, the concentration of chloride ions contained in the preservation solution is preferably 25 ppb or more and less than 250 ppb. Chloride ions also erode circuits in semiconductor manufacturing, so it is required to control them to extremely low concentrations in ultrapure water. On the other hand, since chloride ions exhibit a bactericidal action, it is preferable that they are contained in pure water used as a preservation solution within a range that does not adversely affect semiconductor production.

With the hollow fiber membrane module 1 of the present embodiment described above, it is possible to easily produce ultrapure water that satisfies the water quality requirements when used in semiconductor production while suppressing the growth of fungi during storage. It becomes.

Next, a method for manufacturing the hollow fiber membrane module 1 of the present embodiment will be described.

In the method for producing the hollow fiber membrane module 1 of the present embodiment, first, pure water sterilized by filtration in the case 5 of the hollow fiber membrane module 1 shown in FIG. 1 before being filled with the preservative liquid. Is enclosed.

As the pure water, water filtered by a reverse osmosis membrane or an ultrafiltration membrane as described above is used. The fine particles of 50 nm or more contained in pure water are preferably 10 particles / L or more and 200 particles / L or less.

As for the organic matter content in pure water, it is preferable to use water having a TOC of 1 ppm or more and less than 50 ppm. The TOC is more preferably 5 ppm or more.

Further, the concentration of metal ions contained in pure water is preferably 10 ppb or more and less than 100 ppb, and the concentration of chloride ions contained in pure water is preferably 25 ppb or more and less than 250 ppb.

Then, in the method for producing the hollow fiber membrane module 1 of the present embodiment, the hollow fiber membrane module 1 (case 5) in which pure water sterilized by filtration is sealed is heat-treated at 80 ° C. or higher and lower than 100 ° C. By further heat sterilizing the pure water sterilized by filtration in this way, it is possible to make the storage solution of the hollow fiber membrane module 1 free of bacteria.

The water sterilization method includes addition of chemicals, but in the case of the hollow fiber membrane module used in the ultrapure water production process, sterilization by heating without adding extra components must be performed.

Further, when pure water is sterilized by heating as in the present embodiment, many viable bacteria are killed over time even if the temperature is lower than 80 ° C., but long-term storage of 3 months or more is considered. In that case, it is better to heat it to 80 ° C. or higher to sufficiently kill the bacteria. Further, when the heating temperature is 100 ° C. or higher, pure water boils and the hollow fiber membrane 3a sways in the hollow fiber membrane module 1 and is damaged due to this, or is damaged due to the difference in the coefficient of thermal expansion of the members. May occur. From these viewpoints, the temperature of the heat treatment is preferably 80 ° C. or higher and lower than 100 ° C., more preferably 85 ° C. or higher and 95 ° C. or lower, as in the present embodiment.

Here, when the hollow fiber membrane module 1 is heat-treated as described above, if it is sealed with a rigid member that is hardly deformed by pressure, the pressure inside the module rises due to the thermal expansion of pure water, and the hollow fiber membrane module 1 is hollow. There is a risk that the thread film 3a and the case 5 will be damaged. As a method of avoiding this pressure increase, there is a method of passing through the inside and the outside of the module, but in this case, the water whose volume has expanded due to the heat treatment overflows to the outside, and the outside air due to the volume contraction when further cooling. At that time, fungi may be taken into the module from the atmosphere. In order to avoid this, it is conceivable to carry out the heat treatment step in a sterile room, but it is difficult to manufacture a large hollow fiber membrane module such as that used in the ultrapure water production process in a sterile room.

Therefore, in the method for manufacturing the hollow fiber membrane module 1 of the present embodiment, in order to reduce the pressure increase due to the thermal expansion of the enclosed pure water in the heat treatment step, the pressure is applied to the lower nozzle 5b of the hollow fiber membrane module 1. Provide a shock absorber. Since the hollow fiber membrane module 1 of the present embodiment is used for external pressure filtration, the lower nozzle 5b corresponds to the raw water side port of the present invention.

As a pressure buffering mechanism that prevents the inflow of outside air while buffering the pressure due to expansion, for example, as shown in FIG. 3, a rubber balloon or a plastic bag in a deflated state with respect to the lower nozzle 5b of the hollow fiber membrane module 1 is used. The method of connecting the pressure buffer mechanism 21 made of the above is convenient and preferable. However, in general, a rubber-like flexible substance is vulnerable to heating, and the substance added to give flexibility may dissolve in the pure water with which it comes into contact, which may reduce the purity of the storage solution. Therefore, it is more preferable to cover it with a bag made of a material having a small amount of additives, which has heat resistance to heat treatment, such as a plastic bag made of polyethylene, polypropylene, or the like.

Further, as described above, it is possible to absorb the volume expansion by installing a deflated plastic bag in the nozzle, but if a large amount of water overflows into the bag, it is originally enclosed in the module. The amount of preservative solution to be stored is reduced, and the drying prevention function of the film, which is one of the purposes of encapsulation, becomes insufficient.

In order to avoid this, in the method for manufacturing the hollow fiber membrane module 1 of the present embodiment, in order to absorb the volume expansion due to the heating of the enclosed pure water in the heat treatment step, the lower nozzle 5b of the hollow fiber membrane module 1 is absorbed. It is preferable to provide a volume expansion absorption mechanism.

As the volume expansion / absorption mechanism, for example, as shown in FIG. 3, a volume expansion / absorption mechanism 20 made of polyvinylidene fluoride or polypropylene liquid receiver used for piping of ultrapure water equipment which is resistant to heating and has little concern about elution. Is preferably connected to the lower nozzle 5b. Then, it is more preferable to connect a pressure buffering mechanism 21 made of a member capable of buffering pressure, for example, a bag made of polyethylene or polypropylene, so as to cover the liquid receiver. By having the pressure buffer mechanism 21 and the volume expansion absorption mechanism 20 together in this way, it is possible to carry out sterilization by heat treatment without inhaling outside air by cooling while suppressing the influence of thermal expansion due to heating. You can.

In the heat treatment described above, as shown in FIG. 3, the upper pipe line 10a, the lower pipe line 11a, and the upper nozzle 5a are closed by the sealing members 10b, 11b, and 23, respectively. It is in a state. The upper line 10a and the lower line 11a correspond to the filtration side port in the present invention.

Further, in the method for manufacturing the hollow fiber membrane module 1 of the present embodiment, as shown in FIG. 3, it is preferable to include the sealing member 22 in the pressure buffering mechanism 21. Then, after the heat treatment step, it is preferable to replace the volume expansion absorption mechanism 20 with the sealing member 22 in the pressure buffer mechanism 21, and then remove the pressure buffer mechanism 21 and the volume expansion absorption mechanism 20.

By adopting such a method, the lower nozzle 5b can be sealed while the closed system remains. Further, in the method for manufacturing the hollow fiber membrane module 1 of the present embodiment, the volume expansion absorption mechanism 20 and the pressure buffer mechanism 21 are installed and the sealing member 22 is replaced by the lower nozzle 5b on the raw water side. Therefore, even if fungal contamination occurs, it will occur only on the raw water side where the sealing member 22 is replaced, and fungal contamination will occur on the filtration side, which is a completely sealed system partitioned by the hollow fiber membrane 3a. Can be prevented.

Further, in the step of heat treatment, the configuration for reducing the pressure increase due to the thermal expansion of the enclosed pure water and absorbing the volume expansion of the enclosed pure water is not limited to the configuration shown in FIG. 3, and is not limited to the configuration shown in FIG. The configuration as shown in the above may be adopted. In the hollow fiber membrane module 1 shown in FIG. 4, a polypropylene (PP) bottle 24 and a tube 25 are provided as a volume expansion and absorption mechanism. The polypropylene bottle 24 is attached to the lower nozzle 5b on the raw water side via the tube 25, and is made of polytetrafluoroethylene (PTFE) having a pore size of 0.2 μm as a pressure buffering mechanism with respect to the upper portion of the polypropylene bottle 24. ) Is provided for the air vent filter 26. The air vent filter 26 is capable of permeating gas and impermeable to bacterial cells.

Further, in the hollow fiber membrane module 1 shown in FIG. 4, a polyethylene bag 27 is provided as a gas inflow prevention member for preventing the outside air from flowing into the lower nozzle 5b. The polyethylene bag 27 is provided so as to cover the lower nozzle 5b with the sealing member 22 contained therein. The portion where the tube 25 passes through the polyethylene bag 27 (the portion indicated by the dotted ellipse in FIG. 4) is sealed in a sealed state.

Then, after the heat treatment step, the tube 25 is replaced with the sealing member 22 in the polyethylene bag 27, and then the polyethylene bag 27, the tube 25, the polypropylene (PP) bottle 24, and the air vent filter 26 are lowered. It is preferable to remove it from the side nozzle 5b.

Next, an example of the embodiment in which the hollow fiber membrane module 1 of the present embodiment is installed in the water treatment apparatus 100 for ultrapure water production will be described with reference to FIG. 5, and further, the hollow fiber membrane module 1 of the present embodiment will be described. The filtration method using the above will be described. In the water treatment apparatus 100 for ultrapure water production, a cross-flow filtration method using external pressure filtration is assumed.

As shown in FIG. 5, the water treatment apparatus 100 is used, for example, for a final filter of ultrapure water, and supplies water to be treated from a lower nozzle 5b to a storage portion 5c outside the hollow fiber membrane 3a. The hollow fiber membrane 3a is filtered to the inside (hollow portion) side, and the filtered water (ultrapure water) is discharged from the conduits 10a and 11a at both ends of the hollow fiber membrane bundle 3. Further, the circulating water (concentrated water) is discharged through the upper nozzle 5a.

The water treatment device 100 includes a supply pipe 101 connected to the lower nozzle 5b of the hollow fiber membrane module 1 to supply water to be treated, and a circulation pipe 102 connected to the upper nozzle 5a to send out circulating water. .. Further, a pressure gauge, various valves 101a, 102a and the like are arranged in the middle of the supply pipe 101 and the circulation pipe 102. Further, the water treatment device 100 includes a first filtered water collecting pipe 103 and a second filtered water collecting pipe 104, which serve as a flow path for the filtered water. The first filtered water collection pipe 103 and the second filtered water collection pipe 104 are connected to the filtered water confluence pipe 105, and the confluence pipe 105 is connected to an external pipe (not shown). The merge pipe 105 is provided with a pressure gauge, various valves 105a, and the like.

When installing the hollow fiber membrane module 1 in the water treatment device 100 described above, first, the sealing members 10b, 11b, 22, 23 that seal the hollow fiber membrane module 1 are removed, and the hollow fiber membrane is formed. The pure water (preservative liquid) sealed in the membrane module 1 is discarded except for the piping of the water treatment device 100. After that, the hollow fiber module 1 is attached to the pipe of the water treatment device 100.

Normally, when installing a sterilized hollow fiber membrane module in a water treatment device, in order to prevent contamination of bacteria, attach it to the pipe in a closed form or do not discard the storage solution in the hollow fiber membrane module. Install and discard the preservative in the hollow fiber membrane module while replacing with feed water. However, in the case of a water treatment device for ultrapure water used for a semiconductor device or the like, if the preservative solution in the hollow fiber membrane module is allowed to flow into the system, the cleanliness of the ultrapure water water is lowered and the inside of the system is cleaned. It takes time to get into the state. Therefore, in the present embodiment, the preservative liquid in the hollow fiber membrane module 1 is positively discarded outside the system and then attached to the water treatment device 100.

The air thread membrane module 1 is vertically arranged so that the upper nozzle 5a side faces up, the upper nozzle 5a is connected to the circulation pipe 102, and the conduit 10a of the cap 10 is connected to the first filtered water collecting pipe 103. NS. Further, the lower nozzle 5b is connected to the supply pipe 101, and the pipe line 11a of the cap 11 is connected to the second filtered water collection pipe 104.

The water to be treated is introduced from the supply pipe 101 through the lower nozzle 5b into the storage portion 5c of the hollow fiber membrane module 1 at a predetermined pressure. In the case 5, most of the introduced water to be treated is filtered by the hollow fiber membrane 3a to reach the hollow portion, and moves upward or downward as filtered water. The filtered water that has moved upward or downward escapes into the cap 10 or cap 11 through the opening at the end of the hollow fiber membrane 3a, and flows into each of the pipelines 10a and 11a, the first filtered water collecting pipe 103, or the second filtered water collecting pipe. It is discharged to the confluence pipe 105 through 104 and collected through an external pipe. On the other hand, the water to be treated that has risen in the storage portion 5c in the case 5 without penetrating the hollow fiber membrane 3a is discharged as circulating water from the upper nozzle 5a and sent out to the circulation pipe 102.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to these Examples.

Hollow fiber membrane modules were used in the following examples and comparative examples. Its characteristics and various water quality analysis methods are shown below.

[About hollow fiber membranes]
Material: Polysulfone Fraction Molecular weight: 6000 Da (ultrafiltration membrane)
Inner diameter / outer diameter: 0.6 mm / 1.0 mm

[Case used for manufacturing hollow fiber membrane module]
Material: Polysulfone Shape: Cylindrical Size: Cylindrical inner / outer diameter in the filtration area: 154 mm / 170 mm
Inner diameter / outer diameter of cylindrical part in nozzle part: 162 mm / 183 mm
Nozzle inner diameter: 58 mm
Cylindrical case length / nozzle center distance: 1050 mm / 872 mm

[How to check the bactericidal effect]
The water enclosed in the hollow fiber membrane module was sampled, and the presence or absence of viable bacteria was determined using an HPC total count sampler (model: MHPC10025) manufactured by Millipore. In addition, the state of bacteria counted as fine particles in the filtered water when used as a hollow fiber membrane module was confirmed using UltraDI-50 manufactured by Particle Measuring Systems.

[Analysis of contents of preservative solution]
The concentration of various components in the storage solution (pure water) was analyzed using the following equipment.
Fine particles: UltraDI-50 manufactured by Particle Measuring Systems Co., Ltd.
TOC: Shimadzu TOC5000A
Metal ion concentration: Agilent Technologies 7500cs
Chloride ion concentration: Metrohm 881CompactIC

[Example 1]
Pure water filtered using an ultrafiltration membrane is sealed in a hollow fiber membrane module, the hollow fiber membrane module is placed in an oven, heat treatment is performed at 90 ° C. for 16 hours, and the sterilized pure water is used as the module. It was in a state of being enclosed inside. At the time of this heat treatment, a polyethylene (PE) bag was attached to the nozzle on the raw water side as a pressure buffering mechanism, and a polypropylene (PP) cup was attached as a volume expansion absorption mechanism. After the heat treatment was completed, the nozzle was sealed with a predetermined sealing member, and the nozzle was stored in a storage room whose temperature was adjusted to 20 ° C. to 25 ° C. for 3 months.

After storage for 3 months, pure water enclosed as a preservation solution was sampled, and the number of viable bacteria in the preservation solution was counted. At the same time, the concentrations of TOC, metal ion and chloride ion in the preservation solution were measured. The results are shown in Table 1.

When ultrapure water was produced using this hollow fiber membrane module, filtered water having a water quality that could be used as ultrapure water was obtained immediately after the start of operation.

[Examples 2 and 3]
Counting viable cells after heat treatment and storage, TOC in storage solution, metal ions, and chloride ions in the same manner as in Example 1 except that the heating temperature and heating time were changed to the conditions shown in Table 1. Each concentration of was measured. The results are shown in Table 1. In Example 3, viable bacteria were counted as 3 after storage for 3 months, but when ultrapure water was produced using each hollow fiber membrane module of this example, ultrapure water was immediately started from the start of operation. Filtered water of water quality that can be used as water was obtained.

[Examples 4, 5, 6]
In the same manner as in Example 1, the viable cell count after heat treatment and storage, and the concentrations of TOC, metal ion, and chloride ion in the preservation solution were measured. The results are shown in Table 1. When ultrapure water was produced using each of the hollow fiber membrane modules of this example, filtered water having a water quality that could be used as ultrapure water was obtained immediately after the start of operation.

[Example 7]
The number of viable bacteria after heat treatment and storage was counted and pure water was obtained in the same manner as in Example 1 except that the nozzle on the raw water side was opened without providing the pressure buffer mechanism and the heat treatment was performed without providing the volume absorption mechanism. The concentrations of TOC, metal ions, and chloride ions in the mixture were measured. The results are shown in Table 1. Since a large amount of water overflowed from the nozzle during the heat treatment, an air pool was generated in the module when it was cooled to room temperature. Moreover, since 29 viable bacteria were counted after storage for 3 months, the production test of ultrapure water using the hollow fiber membrane module of this example was not carried out.

[Example 8]
Similar to Example 1, the count of viable cells after heat treatment and storage, TOC in pure water, metal ions, and chloride ions, except that a polypropylene cup was not used as the volume expansion and absorption mechanism. Each concentration was measured. The results are shown in Table 1. During the heat treatment, water leakage into the polyethylene bag as a pressure buffer mechanism was confirmed. When ultrapure water was produced using the hollow fiber membrane module of this example, filtered water having a water quality that could be used as ultrapure water was obtained immediately after the start of operation.

[Example 9]
Pure water filtered using an ultrafiltration membrane is sealed in a hollow fiber membrane module, the hollow fiber membrane module is placed in an oven, heat treatment is performed at 90 ° C. for 16 hours, and the sterilized pure water is used as the module. It was in a state of being enclosed inside. In Example 9, the configuration shown in FIG. 4 is adopted, and when heat treatment is performed, a polypropylene (PP) bottle is attached to the nozzle on the raw water side as a volume expansion and absorption mechanism through a tube. An air vent filter (PTFE filter) made of polytetrafluoroethylene (PTFE) having a pore size of 0.2 μm was attached to the upper part of the polypropylene bottle as a pressure buffer mechanism. After the heat treatment was completed, the nozzle was sealed with a predetermined sealing member placed in a polyethylene bag attached to the nozzle in advance, and stored in a storage room whose temperature was adjusted to 20 ° C to 25 ° C for 3 months. ..

After storage for 3 months, pure water enclosed as a preservation solution was sampled, and the number of viable bacteria in the preservation solution was counted. At the same time, the concentrations of TOC, metal ion and chloride ion in the preservation solution were measured.

When ultrapure water was produced using the hollow fiber membrane module of Example 9, filtered water having a water quality that could be used as ultrapure water was obtained immediately after the start of operation.

[Comparative Example 1]
At the same time as in Example 1, pure water filtered using an ultrafiltration membrane as a preservation liquid was sealed in a hollow fiber membrane module. The module was stored for 3 months in a temperature controlled storage room at 20 ° C to 25 ° C. After storage for 3 months, pure water enclosed as a preservation solution was sampled, and the number of viable bacteria in the preservation solution was counted. In addition, the concentrations of TOC, metal ions, and chloride ions in the preservation solution were also measured. The results are shown in Table 1. In this comparative example, a large number of viable bacteria (difficult to count at 100 or more) were confirmed in pure water, which is a preservation solution.
When the production of ultrapure water was carried out using this hollow fiber membrane module, a large number of fine particles derived from viable bacteria were observed in the filtered water, and it took 14 times longer time than in Example 1 to reduce the fine particles.

1 Hollow thread film module 3 Hollow thread film bundle 3a Hollow thread film 5 Case 5a Upper nozzle 5b Lower nozzle 5c Reservoir 10, 11 Cap 10a, 11a Pipe line 10b Sealing member 12 O ring 13 Nut 14 Adhesive part 20 Volume expansion absorption Mechanism 21 Pressure buffer mechanism 22 Sealing member 23 Sealing member 24 Polypropylene (PP) bottle 25 Tube 26 Air vent filter 27 Polyethylene bag 100 Passing device 101 Supply pipes 101a, 102a Various valves 102 Circulation pipe 103 First filtered water collection pipe 104 Second filtered water collection pipe 105 Confluence pipe 105a Various valves

Claims (11)

A filtration membrane used for filtering liquid and a case in which the filtration membrane is housed are provided.
A filtration membrane module in which sterilized pure water is filled in the case as a preservative liquid for maintaining the filtration performance of the filtration membrane.
The organic matter content in the preservation solution is 5 ppm or more and less than 50 ppm as TOC (Total Organic Carbon).
The concentration of metal ions contained in the preservation solution is 10 ppb or more and less than 100 ppb.
A filtration membrane module in which the concentration of chloride ions contained in the preservation solution is 25 ppb or more and less than 250 ppb. A filtration membrane module including a filtration membrane used for filtering a liquid and a case in which the filtration membrane is housed, as a preservative liquid for maintaining the filtration performance of the filtration membrane in the case. A method for manufacturing a filtration membrane module filled with sterilized pure water.
Pure water sterilized by filtration is sealed in the case containing the filtration membrane, and the case containing the pure water is heat-treated at 80 ° C. or higher and lower than 100 ° C. to inside the filtration membrane module. Pure water was sterilized to obtain the preservation solution .
In the step of heat-treating the case filled with pure water,
A method for manufacturing a filtration membrane module, which comprises providing a volume expansion absorption mechanism on the raw water side of the filtration membrane module in order to absorb the volume expansion due to the heat of the enclosed pure water. In the step of heat-treating the case filled with pure water,
The method for manufacturing a filtration membrane module according to claim 2 , wherein a pressure buffering mechanism is provided on the raw water side of the filtration membrane module in order to reduce a pressure increase due to thermal expansion of the enclosed pure water. The pure water sterilized by the filtration is water filtered by an ultrafiltration membrane or a reverse osmosis membrane, and the amount of fine particles of 50 nm or more contained in the pure water is 10 / L or more and 200 / L or less. The method for manufacturing a filtration membrane module according to claim 2 or 3. The method for producing a filtration membrane module according to any one of claims 2 to 4 , wherein the organic matter content in the pure water is 5 ppm or more and less than 50 ppm as TOC (Total Organic Carbon). The method for manufacturing a filtration membrane module according to any one of claims 2 to 5 , wherein the concentration of metal ions contained in the pure water is 10 ppb or more and less than 100 ppb. The method for producing a filtration membrane module according to any one of claims 2 to 6 , wherein the concentration of chloride ions contained in the pure water is 25 ppb or more and less than 250 ppb. In the step of heat-treating the case filled with pure water,
To reduce the pressure rise due to thermal expansion of the pure water the sealed, since the filtering membrane module further provided pressure buffer mechanism raw water side of absorbs volume expansion due to heat of pure water the encapsulated the filtration membrane module The method for manufacturing a filtration membrane module according to claim 2 , wherein the volume expansion and absorption mechanism is provided on the raw water side of the above, and the filtration side of the filtration membrane module is in a sealed state. The filtration membrane module is a hollow fiber membrane module in which a hollow fiber membrane is housed as the filtration membrane in the case, and communicates with a filtration side port communicating with the hollow portion of the hollow fiber membrane and the outside of the hollow fiber membrane. Has a raw water side port and
In the step of heat-treating the case filled with pure water,
The raw water side port is provided with the volume expansion absorption mechanism, the pressure buffer mechanism is provided with a sealing member contained in the pressure buffer mechanism, and the filtration side port is sealed.
8. The eighth aspect of claim 8, wherein after the heat treatment step, the volume expansion / absorption mechanism is replaced with the sealing member in the pressure buffering mechanism, and then the pressure buffering mechanism and the volume expansion / absorption mechanism are removed. A method for manufacturing a filtration membrane module. The filtration membrane module is a hollow fiber membrane module in which a hollow fiber membrane is housed as the filtration membrane in the case, and communicates with a filtration side port communicating with the hollow portion of the hollow fiber membrane and the outside of the hollow fiber membrane. Has a raw water side port and
In the step of heat-treating the case filled with pure water,
The raw water side port is provided with the volume expansion and absorption mechanism, and the volume expansion and absorption mechanism is provided with the pressure buffer mechanism capable of allowing gas to permeate and not allowing bacterial cells to permeate, and further, the raw water side port is provided with the pressure buffer mechanism. A gas inflow prevention member for preventing the inflow of outside air is provided in a state where the gas inflow member contains a sealing member, and the filtration side port is sealed.
After the heat treatment step, the volume expansion absorption mechanism is replaced with the sealing member in the gas inflow prevention member, and then the volume expansion absorption mechanism provided with the pressure buffer mechanism and the gas inflow prevention member are removed. The method for manufacturing a filtration membrane module according to claim 8 , wherein the filtration membrane module is manufactured. The filtration membrane module manufactured by the manufacturing method according to claim 9 or 1 0, in the process of attaching the piping of the water treatment device,
The sealing member that seals the filtration side port and the raw water side port of the filtration membrane module is removed.
A method for installing a filtration membrane module, which comprises disposing of pure water sealed in the filtration membrane module other than the piping of the water treatment device, and then attaching the piping of the water treatment device.

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