JPH078763A - Hollow fiber membrane filtration device - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the number of presser bolts, prevent them from falling off, losing and galling (seizure), and improving maintainability. [Structure] An airtight container 1 is divided into a lower filtration chamber 3 and an upper processing liquid chamber 4 by a module mounting plate 2, and a hollow fiber membrane module 5 is suspended on the module mounting plate 2. The hollow fiber membrane module 5 is sandwiched between a perforated plate holding plate 8 and the module mounting plate 2, and is fixed by a holding bolt 20 via a retaining member 23. As a result, the rigidity of the holding plate 8 can be increased and the number of holding bolts 20 can be reduced.

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 filtering device using a hollow fiber membrane module as a filter material, and particularly to reducing the number of holding bolts to reduce the exposure of workers in periodic inspections and maintenance. TECHNICAL FIELD The present invention relates to a hollow fiber membrane filtration device with improved properties.

[0002]

2. Description of the Related Art Generally, in a nuclear power plant,
As a measure to reduce radiation, the clad (corrosion product) is suppressed and removed. For example, radioactive waste liquid or filtration to separate and remove the suspension present in the condensate in the condensate supply system of the reactor is removed. The device is in use.

As the filtering device, a filtering device using a precoat filter such as a powder ion exchange resin, a flat film type filtering filter such as a filter paper, a filter cloth, a membrane filter, etc., a sintered metal, a ceramic or the like has been conventionally used. An empty tube type filter is used. However, in recent years, a hollow fiber membrane filtering device using a hollow fiber membrane as a filtering material has become widespread.

This hollow fiber membrane is a hollow fiber membrane having an outer diameter of 0.3 to 3 mm and a large number of fine permeation holes, and a particle diameter of 0.1 μm.
It can capture suspended matter of m or less, has a large filtration area per unit volume, and has excellent pressure resistance.
As a filter medium for ultrafiltration and reverse osmosis filtration, the electronics industry,
Widely used in fields such as medicine and wastewater treatment.

FIG. 8 is a longitudinal sectional view showing an example of a hollow fiber membrane filtering device. This hollow fiber membrane filtration apparatus is divided into a closed container indicated by reference numeral 1 and a closed chamber 1 by a module mounting plate 2 into a lower filtration chamber 3 and an upper treatment liquid chamber 4, and the inside of the filtration chamber 3 is surrounded by the filtration chamber 3. Is configured by vertically arranging a plurality of hollow fiber membrane modules 5.

Each hollow fiber membrane module 5 is fixed to the module mounting plate 2 via a module fixing portion 7 in which a large number of hollow fiber membranes 6 are bundled and fixed, and the module mounting plate 2 is a hermetic container 1. Lower outer peripheral flange 9 and upper outer peripheral flange attached to the edges of the body 1a and the lid 1b of
It is clamped and fixed by 10.

The hollow fiber membrane module 5 generally has a module structure in which a large number of fibrous hollow fiber membranes 6 are bundled in a straight line or U-shape and the periphery of the open end is fixed by a resin or the like.
The module fixing portion 7 is formed by fixing the resin or the like. The hollow fiber membrane 6 is supported by a holding plate 8 extending from the module fixing portion 7.

Further, the hollow fiber membrane module 5 is fitted and fixed by the module fixing portion 7 into the mounting hole formed in the module mounting plate 2 shown in FIG.
Mounted on the module mounting plate 2 and the pressing plate 8 and fixed by a pressing bolt 20. The cylindrical protection tube 15 has an opening 19 depending from the filtration chamber 3.
FIG. 9 shows a state in which the holding bolt 20 is attached to the module mounting plate 2, and 21 in the figure indicates a disc spring washer.

Here, the waste liquid generated from the nuclear power plant is introduced from the feed liquid inlet nozzle 11 into the filtration chamber 3 as shown by the solid arrow, and when passing through the surface of the hollow fiber membrane 6, clad or the like is generated. The foreign matter is separated and removed and filtered, and the filtered treatment liquid passes through the hollow portion of the hollow fiber membrane 6, penetrates the module mounting plate 2 and flows into the treatment liquid chamber 4, and then passes through the treatment liquid outlet nozzle 12 to the system. Transferred outside.

In the hollow fiber membrane filtering device having this structure, an air layer 13 may be formed in the upper part of the filtration chamber 3 after the filtration process of a predetermined volume of the feed liquid. This air layer 13 is formed by fine air bubbles in water, air bubbles adhered to the inner surface of the pipe or the surface of the equipment, etc., gradually accumulating in the upper part by long-term operation. In order to discharge the air, a valve (not shown) located downstream of the pipe of the nozzle of the vent 14 was opened to discharge the air together with the supply liquid to the waste treatment system.

This valve and 14 are also used for backwashing operation for removing the clad and the like adhering to the surface of the hollow fiber membrane 6 when the permeation pressure loss increases due to clogging of the hollow fiber membrane 6. To do.

During the backwashing operation, the backwashing air is introduced from the air inlet nozzle 16 provided at the bottom of the filtration chamber 3 as shown by the dotted arrow, and the air is blown out as air bubbles from the air blowing pipe 17, The impact force of the rising bubbles vibrates the hollow fiber membrane 6 of the hollow fiber membrane module 5 to peel off and remove the clad and the like adhering to the surface of the hollow fiber membrane 6 to regenerate the filtration function of the hollow fiber membrane. The backwash water used for the backwash is transferred to the wastewater treatment facility from the backwash water outlet nozzle 18 provided at the bottom of the filtration chamber 3.

[0013]

In the above-mentioned conventional hollow fiber membrane filtering device, as shown in FIG.
Are arranged on the holding plate 8 and the module mounting plate 2, but one hollow fiber membrane module 5 is fixed by the three holding bolts 20 arranged in an equilateral triangle.
The structure has a large number of 20 (see II in Fig. 10).

For example, in the case of the conventional example shown in FIG. 10, the number of holding bolts 20 is 198 for 173 hollow fiber membrane modules 5. For this reason, during maintenance such as replacement of the hollow fiber membrane module 5, bolt removal and attachment work (detachment work) becomes enormous, and the work time becomes long, so that the radiation exposure dose of the worker also increases.

Further, as shown in FIG. 9, the holding bolt 20 is
Although the holding plate 8 is sandwiched and fixed to the module mounting plate 2, the holding bolts 20 removed during maintenance are dropped, and since there are a large number, there is a high possibility that they will be lost.

Particularly, since the holding bolt 20 and the disc spring washer 21 are disjointed, there is a high possibility of loss. In addition, since the number of the holding bolts 20 is large, there is a problem that galling (seizure) of the bolts is likely to occur at the time of mounting and removing the bolts.

The present invention has been made to solve the above-mentioned problems. The number of presser bolts is reduced to improve maintenance workability, work time is shortened, and radiation exposure of workers is reduced. Another object of the present invention is to provide a hollow fiber membrane filtration device that prevents the bolt from falling off and is lost, and that prevents the bolt from being seized even if the work of attaching and detaching the holding bolt is repeated.

[0018]

The present invention has a module mounting plate that divides the inside of a closed container into a lower filtration chamber and an upper processing liquid chamber, and a hollow fiber membrane module suspended from this module mounting plate. In the hollow fiber membrane filtration device, the hollow fiber membrane module is sandwiched between a perforated plate holding plate having holes at positions corresponding to the respective module positions and the module mounting plate, and fixed through a retaining bolt with a retaining bolt. It is characterized by being.

The hollow fiber membrane modules are arranged on the module mounting plate in a zigzag pattern at regular pitches in an equilateral triangle, and three hollow fiber membrane modules adjacent to each other at arbitrary positions have a pitch equal to or less than twice the pitch. It is fixed by at least three holding bolts arranged in a staggered manner in a triangular shape.

Further, the holding bolt is arranged at the center of gravity of an equilateral triangle formed at the center points of the hollow fiber membrane modules adjacent to each other. At the position of the presser bolt, a retainer having a screw hole portion having almost the same diameter as the retainer bolt is arranged on the retainer plate, and the distance from the upper surface of the module mounting plate to the lower end of the retainer screw hole is It is longer than the thread of the bolt.

The diameter of the lower part of the neck of the presser bolt is smaller than the nominal diameter of the threaded portion, its length is longer than the thickness of the retaining member, and the retaining member is hollow, and its diameter is smaller than the nominal diameter of the threaded portion. It has a large shape.

[0022]

[Function] Since the holding bolts are arranged so that three adjacent hollow fiber membrane modules located at arbitrary positions are fixed in an equilateral triangle shape by the three holding bolts, the number of holding bolts is greatly reduced. Therefore, maintenance workability is improved, work time is shortened, and radiation exposure of workers can be reduced.

Further, since the retainer plate is provided with a retainer, the retainer bolt loosened during maintenance work can be temporarily fixed to the retainer screw hole by screwing, so that the retainer bolt and the disc spring washer are prevented from falling off or being lost. Is possible.

Further, even if the material of the presser bolt and the module mounting plate is the same stainless steel, the steel types are changed to have different hardness, so that it is difficult to bite even if the bolts are repeatedly attached and detached.

Further, the diameter of the lower part of the neck of the presser bolt is made smaller than the nominal diameter of the threaded portion, so that the bolts are tightened even if the core of the screw hole of the module mounting plate and the core of the retaining screw hole are slightly misaligned. There are no problems and maintenance workability is good.

[0026]

EXAMPLE An example of the hollow fiber membrane filtering apparatus according to the present invention will be described with reference to FIGS. 1 to 5. In the figure,
The same components as those of the conventional technique shown in FIGS. 8 to 10 are designated by the same reference numerals for description.

In the hollow fiber membrane filtration apparatus according to the embodiment of the present invention shown in FIG. 1, the closed container 1 is divided into a lower filtration chamber 3 and an upper treatment liquid chamber 4 by a module mounting plate 2, and the filtration chamber is A plurality of hollow fiber membrane modules 5 in which a large number of hollow fiber membranes 6 are bundled and fixed are vertically provided at 3. In this hollow fiber membrane module 5, the module fixing portion 7 at the upper end is fitted and fixed in a mounting hole (not shown) provided in the module mounting plate 2.

A lower outer peripheral flange 9 and an upper outer peripheral flange 10 are attached to the body 1a and the lid 1b and fastened so that watertightness is maintained. A supply liquid inlet nozzle 11 is attached to the side of the body 1a, and a treatment liquid outlet nozzle 12 is attached to the upper surface of the lid 1b. Note that FIG.
In the figure, reference numeral 13 is an air layer, 14 is a vent, 15 is a protective cylinder, 16 is an air inlet nozzle, 17 is an air outlet pipe, and 18 is a backwash water outlet nozzle.

FIG. 2 shows a state in which the holding bolt 20 is screwed into the module mounting plate 2 through the retainer 23 and is screwed into the screw hole 33 of the mounting plate. FIG. 3 shows the holding bolt 20, where 24 is a constricted portion and 25 is a screw portion.

FIG. 4 shows the relationship between the retainer 23 and the module mounting plate 2. A through hole 35 is provided at the center of the retaining hole 23, and a retaining screw hole 34 is formed on the inner surface of the through hole 35. In the hollow fiber membrane module 5, the brim 26 of the module fixing portion 7 is sandwiched between the module mounting plate 2 and the holding plate 8, fixed by the holding bolt 20 via the retainer 23, and hung in the filtration chamber 3. It is housed in a cylindrical protection tube 15 that is open.

As shown in part I of FIG. 6, the holding bolts 20 and the retainers 23 are arranged in a zigzag in a regular triangle at a constant pitch, and three adjacent hollow fiber membrane modules 5 are arranged at arbitrary positions.
Are arranged in an equilateral triangle so as to be surrounded by three. In addition, in FIG. 6, the holding bolt 20 and the retainer 23 on the holding plate 8 are
FIG. 3 is a plan view showing an example of the arrangement of the above, where the small circles indicate the holding bolts 20 and the retainers 23, and the large circles indicate the module openings 22.

The presser bolts 20 and the retainers 23 are arranged at a pitch twice the arrangement pitch of the hollow fiber membrane modules 5, and are located at the center of gravity of an equilateral triangle formed by the center points of adjacent hollow fiber membrane modules 5. . For example, in the case of FIG. 6, the number of the holding bolts 20 is 64 for 173 hollow fiber membrane modules 5.

The outer peripheral portion of the retainer plate 8 may not satisfy the above arrangement, but in that case, the number of the retainer bolts 20 is set so that the number of the hollow fiber membrane modules 5 surrounded by the retainer bolts 20 is 3 or less. Or decrease the arrangement pitch of the presser bolts 20.

Further, as shown in FIG. 5, the retaining member 23 is arranged and fixed on the pressing plate 8 so that the core of the screw hole 33 of the mounting plate and the core of the retaining screw hole 34 coincide with each other. At the time of maintenance, loosen the holding bolt 20, remove the holding bolt 20 from the screw hole 33 of the mounting plate, raise the holding bolt 20, and hook the holding bolt 20 in the retaining screw hole 34. It is not necessary to remove the holding bolt 20 from the retainer 23.

As shown in FIGS. 3 and 4, since the length A of the presser bolt screw portion 25 is shorter than the length B from the upper surface of the module mounting plate 2 to the lower end of the retaining hole 34 for retaining, the presser bolt 20 Does not simultaneously catch on the threaded portions of both the module mounting plate 2 and the retaining member 23.

Further, the diameter of the lower portion of the neck of the presser bolt 20 is smaller than the nominal diameter of the threaded portion, and its length is longer than the thickness of the retainer 23. The material of both the holding bolt 20 and the module mounting plate 2 is stainless steel, but the hardness is changed by changing the steel type. For example, the module mounting plate 2 is SUS304,
The holding bolt 20 is SUS630 or the like.

Next, the operation of the above configuration will be described. As shown in FIG. 6, since the number of presser bolts can be reduced to about 1/3, workability at the time of maintenance is improved, work time is shortened, and worker's radiation exposure can be reduced.

As shown in FIG. 5, since the retainer 23 is also provided with a retaining screw hole 34 of the same size as the holding bolt 20, the loosening of the retaining bolt 20 is prevented during maintenance.
It is not necessary to remove the holding bolt 20 and the disc spring washer 21 because it can be temporarily fixed by screwing to. For this reason, not only the presser bolt 20 and the disc spring washer 21 can be prevented from falling, but also the parts are not removed because they are not removed from the presser plate 8.

Further, by attaching the retainer 23 to the holding plate 8, the rigidity of the fixing portion is increased, so that even if the number of the holding bolts 20 is reduced, there is no problem in the strength of the holding plate 8.

Further, as shown in FIG. 2, since the diameter of the holding bolt neck portion 24 of the holding bolt 20 is smaller than the nominal diameter of the screw portion 25, the core of the screw hole 33 of the holding bolt and the retainer 23 Even if the core of the screw hole is slightly displaced, the presser bolt 20 and the retainer 23 do not interfere with each other. Therefore, the presser bolt 20
There is no problem in tightening and the maintenance work is improved.

Since the length of the presser bolt screw portion 25 is shorter than the distance from the upper surface of the module mounting plate 2 to the lower end of the retaining screw hole 34, the retaining bolt 20 is attached to both the module mounting plate 2 and the retaining member 23. Since they are not caught at the same time, the holding bolt 20 is completely removed from the module mounting plate 2. In other words, the pressing plate 8 will not be accidentally pulled up with the pressing bolt 20 still attached to the module mounting plate 2.

Further, both the presser bolt 20 and the module mounting plate 2 are made of stainless steel, but by changing the steel type to have a hardness difference, it becomes difficult to bite even if the bolts are repeatedly attached and detached. In addition, the number of presser bolts 20 has been greatly reduced, which makes it more difficult to bite.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 7 shows an example of a hollow fiber membrane filtration device used for condensate treatment in a condensate water supply system for a reactor. The same parts as those in FIG. 1 are designated by the same reference numerals, and duplicated description will be omitted. In the figure, reference numeral 27 is a water collection pipe, 28 is a joint, 29 is a closure, and 30 is a closure.
Is a spacer, 31 is a dimple, and 32 is a rectifying tube. The other parts are almost the same as the configuration shown in FIG.

A plurality of hollow fiber membrane modules 5 vertically installed in the filtration chamber 3 are connected in series. Generally, since a large volume of condensate is treated, the diameter of the closed container 1 also becomes large and the number of hollow fiber membrane modules 5 also becomes large.
The number of the holding bolts 20 also increases, and the effect of the present invention becomes remarkable by adopting the structure shown in FIGS. 2 to 5.

[0045]

According to the present invention, by providing a retaining plate on the retainer plate and reviewing the method of arranging the retainer bolts, it is possible to greatly reduce the retainer bolts and improve the workability of maintenance. The work time can be shortened, and the exposure of workers can be reduced.

Further, since the retaining bolt can be screwed to the retaining screw portion, the retaining bolt is prevented from falling off and the retaining bolt and the disc spring washer are prevented from being lost. Since the screw length of the presser bolt is shorter than the length from the top surface of the module mounting plate to the lower end of the retaining screw, the presser bolt does not catch on both at the same time. Can be protected.

Further, since the diameter of the lower part of the neck of the presser bolt is smaller than the diameter of the screw part, there is no problem in tightening the presser bolt even if the cores of the screw holes of the module mounting plate and the retaining hole are slightly misaligned, and maintenance is possible. Workability is improved.

Further, the material of the presser bolt and the module mounting plate is stainless steel, but by changing the steel type and giving a hardness difference, the presser bolt becomes hard to be galvanized even if the bolts are repeatedly attached and detached, and the number of presser bolts is greatly increased. Since it has been reduced to 1, the structure will be more difficult to bite.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a hollow fiber membrane filtering device according to the present invention.

FIG. 2 is an enlarged vertical sectional view showing a state in which the holding bolt in FIG. 1 is attached to a module mounting plate.

FIG. 3 is an elevation view showing the presser bolt in FIG.

FIG. 4 is a vertical cross-sectional view showing the relationship between the retainer and the module mounting plate in FIG.

FIG. 5 is an enlarged vertical cross-sectional view showing a state in which the holding bolt in FIG.

FIG. 6 is a plan view showing an arrangement example of the holding bolts of the holding plate in FIG.

FIG. 7 is a vertical cross-sectional view showing another embodiment of the hollow fiber membrane filtration device according to the present invention.

FIG. 8 is a vertical cross-sectional view showing a conventional hollow fiber membrane filtration device.

9 is an enlarged vertical sectional view showing a state in which the holding bolt in FIG. 8 is attached to a module mounting plate.

10 is a plan view showing an arrangement example of the holding bolts of the holding plate in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Airtight container, 1a ... Body, 1b ... Lid body, 2 ... Module mounting plate, 3 ... Filtration chamber, 4 ... Processing liquid chamber, 5 ... Hollow fiber membrane module, 6 ... Hollow fiber membrane, 7 ... Module fixing part, 8 ...
Holding plate, 9 ... Lower peripheral flange, 10 ... Upper peripheral flange, 11 ... Supply liquid inlet nozzle, 12 ... Treatment liquid outlet nozzle, 13
... Air layer, 14 ... Vent, 15 ... Protective cylinder, 16 ... Air inlet nozzle, 17 ... Air outlet pipe, 18 ... Backwash water outlet nozzle, 19 ... Opening, 20 ... Press bolt, 21 ... Disc spring washer, 22 ... Module opening, 23… Prevention, 24… Holding part of presser bolt, 25
... Presser bolt screw part, 26 ... Brim, 27 ... Water collecting pipe, 28 ... Joint, 29 ... Closer, 30 ... Spacer, 31 ... Dimple, 32 ...
Rectifier tube, 33 ... Mounting plate screw hole, 34 ... Prevention screw hole,
35 ... Through hole.

Claims (5)

[Claims] 1. A hollow fiber membrane filtration device comprising a module mounting plate for partitioning a sealed container into a lower filtration chamber and an upper processing liquid chamber, and a hollow fiber membrane module suspended from the module mounting plate, The hollow fiber membrane module is sandwiched between a perforated plate holding plate having holes at positions corresponding to the respective module positions and the module mounting plate, and is fixed through a retaining bolt with a holding bolt. A hollow fiber membrane filtration device. 2. The hollow fiber membrane modules are arranged in a zigzag pattern in a regular pitch on the module mounting plate in an equilateral triangle shape, and three hollow fiber membrane modules adjacent to each other at arbitrary positions have a pitch equal to or less than twice the pitch. 2. The hollow fiber membrane filtration device according to claim 1, wherein the hollow fiber membrane filtration device is fixed by at least three holding bolts arranged in a zigzag in a regular triangle. 3. The hollow fiber membrane filtration device according to claim 1, wherein the holding bolt is arranged at the center of gravity of an equilateral triangle formed by the center points of the adjacent hollow fiber membrane modules. 4. A retainer is provided on the retainer plate at a position of the retainer bolt, the retainer having a screw hole portion having substantially the same diameter as the retainer bolt, and the retainer screw hole is provided from an upper surface of the module mounting plate. The distance to the lower end of the holding bolt is longer than the length of the threaded portion of the holding bolt.
The hollow fiber membrane filtration device described. 5. The diameter of the lower portion of the neck of the presser bolt is smaller than the nominal diameter of the threaded portion, the length thereof is longer than the thickness of the retaining member, and the retaining member is hollow, and the diameter thereof is the threaded portion. The hollow fiber membrane filtration device according to claim 1, wherein the hollow fiber membrane filtration device has a larger diameter than the nominal diameter.