JPH01284306A - Hollow fiber membrane-type filter - Google Patents

Abstract

PURPOSE:To prevent the clogging of an inlet part by forming the inlet part of the lower mounting seat for a level gage for detecting the level of backwashing water for a hollow fiber membrane module provided in a closed versel into such a shape that a clad does not flow into the inlet part. CONSTITUTION:A closed vessel 1 is separated by a tube plate 2 into a filtration chamber 3 and a processing soln. chamber 4. Plural hollow fiber membrane modules 5 are suspended in the filtration chamber 3 in multiple stages. A level gage 20 for detecting the level of backwashing water is hung from the closed vessel 1 through the lower mounting seat 18 and the upper mounting seat 21. A T-tube 24 with the upper end closed and the lower end opened is connected to the inlet part 18a of the lower mounting seat 18. Since the T-tube 24 is connected in this way, the flowing of the clad 22 suspended in the filtration chamber 3 into the lower mounting seat 18 is prevented, and the liq. level in the filtration chamber can be accurately measured.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a hollow model filtration device.

(Prior Art) Generally, in nuclear power plants, generation of corrosion products is suppressed and removed as radiation reduction measures. For example, filtration devices are used to separate and remove suspended matter present in radioactive waste liquid generated in nuclear power plants or condensate in a nuclear reactor condensate water supply system. Conventional methods for this filtration device include methods that use pre-coated filters such as powdered ion exchange resin, methods that use flat membrane filters such as filter paper and filter cloth membrane filters, and hollow tubes such as sintered metal and ceramic filters. One way is to use a type filter.

However, filtration methods using powdered ion exchange resins generate a wide range of resin waste. Furthermore, in the case of using a flat membrane filter or a hollow tube filter, the circulating flow rate becomes large, which complicates the structure of the filtration device, and in addition, there is a problem that the equipment cost becomes enormous. Furthermore, secondary waste is generated during the filtration process, and the filtration rate is also low.

Hollow fiber membranes have become popular as a means of improving the shortcomings of conventional filter media. Hollow fiber membranes generally have an outer diameter of 0.3 to 3 #
It is a hollow fibrous membrane with a size of about 11 and many fine permeation pores.It has a large filtration area per unit volume of light and has excellent pressure resistance, so it is suitable for extreme applications.

Used as a filter material for reverse osmosis filtration, electronic industry, and medicine.

Widely used in the field of wastewater treatment.

Therefore, a conventional filtration device using a hollow fiber membrane will be explained with reference to FIG.

The closed container 1 is divided into a filtration chamber 3 and a processing liquid chamber 4 by a tube plate 2 . A plurality of hollow fiber membrane modules 5 are vertically installed in the filtration chamber 3 in multiple stages.

Each hollow fiber membrane 6 is fixed to the tube plate 2 via a module fixing part 7, and the tube plate 2 is held between the outer periphery 7 flanges 8 and 9 attached to the edges of the body 1A and lid plate 1B of the closed container 1. and fixed in the airtight container 1.

The hollow fiber membrane module 5 generally has a module structure in which a large number of fibrous hollow fiber membranes are bundled in a linear or zero-shape, and the ends are fixed with resin or the like, and the part fixed with resin or the like fixes the module. Department. In the conventional hollow fiber membrane type filtration device shown in FIG. 5, three hollow fiber membrane modules 5 in which hollow fiber membranes 6 are bundled in a straight line and their ends are fixed are arranged in series, and the module fixing part 7 An example is shown in which the membrane modules are connected with connectors and installed as an integral hollow fiber membrane module structure.

The stock solution passes through the stock solution inlet nozzle 10 and is introduced into the filtration chamber 3, and when passing through each hollow fiber membrane 6, it is filtered to separate and remove tribute materials such as crud. The filtered treatment liquid passes through the hollow part of the hollow fiber membrane 6, flows into the water collection pipe 11 provided at the center of the bundle of each hollow fiber membrane module 5, reddens the tube plate 2, and flows into the treatment liquid chamber 4. . and! 2!1 It passes through the physical liquid outlet nozzle 12 and is transferred to the outside of the system.

Note that the mark @15 in the figure is a vent, and 16 is a protection tube.

After filtering a predetermined 8 liters of raw solution, or due to clogging of the hollow fibers 8 and 6, which are the filter media, the permeation pressure loss increases, resulting in a pressure difference between the raw solution inlet side and the treated liquid outlet side of the filtration device. At the point when the value is different from a predetermined value, a backwashing operation is required to remove crud, etc. attached to the surface of the hollow fiber membrane 6.

In the above backwashing operation, the filtration chamber 3 is first filled with a stock solution as backwash water. In this state, pressurized air is blown from the treatment liquid outlet side nozzle 12 to equalize the pressure before and after the hollow fiber membrane 6 and separate the cladding. At the same time, filtration chamber 3
Pressurized air is also supplied to the air blowing pipe 13 provided at the bottom of the air blowing pipe 13 to generate air bubbles through a small hole bored at the bottom of the air blowing pipe 13. The air bubbles collide with the surface of the hollow fiber membrane 6, and foreign matter such as clogging components and crud attached to the hollow fiber membrane 6 is removed by the vibration action (hereinafter referred to as bubbling). Backwash water remaining in the filtration chamber 3 after the bubbling operation for a certain period of time is discharged from the backwash water outlet nozzle 14. Next, in addition to the above-mentioned backwashing operation, an operation is repeated in which the water level of backwash water is set particularly in the region of the hollow fiber membrane where the adhesion of crud, etc. is significant, and backwashing bubbles are applied from the lower part of the filtration chamber. The level of backwash water is set according to the readings from the attached liquid level detection equipment.

A liquid level gauge for detecting this liquid level will be explained below with reference to FIG. Reference numeral 20 denotes a liquid level meter as liquid level detection equipment that detects the water level of backwash water set in the range from the upper end to the lower end of the hollow fiber membrane module structure installed vertically in the filtration chamber 3. This liquid level gauge 20 communicates between an upper mounting seat 21 that communicates with the filtration chamber 3 and led out from the end surface of the tube plate 2, and a lower mounting seat 22 that leads out from the filtration chamber below the lower end of the hollow fiber membrane module 5. It is attached to the main valve 19 via the main valve 19. Therefore, the liquid level gauge 20 accurately indicates the position of the backwash water level at any position along the entire length of the hollow fiber membrane module structure. An air inlet nozzle 17 is installed at the bottom of the filtration chamber 3.
Air Suita pipe 13 that supplies air bubbles into the backwash water connected to
will be placed.

(Problem to be Solved by the Invention) In a conventional filtration device of this type, as partially shown in FIG. The liquid accumulates at the inlet of the seat 18 on the side of the sealed container 1, that is, the inlet, and either clogs the inlet or narrows and blocks the flow path leading to the liquid level gauge 20, causing the liquid level detection equipment to act. There was a problem with it disappearing.

[Structure of the Invention] (Means for Solving the Problems) The present invention divides the inside of a closed container into a filtration chamber and a processing liquid chamber by a temporary tube, and inserts a hollow fiber membrane module structure into the filtration chamber from the tube plate. In a hollow fiber membrane type filtration device equipped with a liquid level needle that is installed vertically and detects the water level of backwash water set in an area from the upper end to the lower end of the hollow fiber membrane module structure, the liquid level needle is It is characterized in that the inlet port of the lower mounting seat is formed in a shape that prevents floating cladding or the like from flowing into the closed container.

(Function) Since crud floating in the filtration chamber does not flow into the inlet of the lower mounting seat where the liquid level needle is attached, clogging does not occur in the channel of the liquid level needle from the inlet. Therefore, the liquid level in the filtration chamber can be accurately measured using the liquid level needle.

(Example) Hereinafter, an example of a hollow fiber membrane type filtration device according to the present invention will be described with reference to FIGS. 1 and 2.

The closed container 1 is divided into a filtration chamber 3 and a processing liquid droplet 4 by a tube plate 2. A plurality of hollow fiber membrane modules 5 are vertically installed in the filtration chamber 3 in multiple stages.

Each hollow fiber membrane 6 is fixed to the tube plate 2 via a module fixing part 7. The tube plate 2 is clamped and fixed to the closed container 1 by the outer periphery 7 flanges 8 and 9 attached to the edges of the body 1A and the lid plate 1B of the closed container 1. The hollow fiber membrane module 5 has a module structure in which a large number of fibrous hollow fiber membranes are bundled in a linear or U-shape, and the ends are fixed with resin or the like, and the part fixed with resin or the like is covered by the module fixing part. .

In a hollow fiber membrane type filtration device, three hollow fiber membrane modules 5 in which hollow fiber membranes 6 are bundled in a straight line and the ends are fixed are arranged in series, and the module fixing parts 7 are connected with a connector to form an integral structure. It is installed as a hollow fiber membrane module structure.

The stock solution passes through the stock solution inlet nozzle 10 and is introduced into the filtration chamber 3, and when passing through each hollow fiber membrane 6, foreign matter such as crud is separated and filtered. The filtered treatment liquid passes through the hollow portion of the hollow fiber membrane 6 and flows into the water collection pipe 11 provided at the center of each bundle of hollow fiber membrane modules 5. The processing liquid that has flowed into the water collection pipe 11 flows into the processing liquid droplet 4 via the tube plate 2, and is transferred to the outside of the system through the processing liquid outlet nozzle 12.

An air Suita pipe 13 is disposed at the bottom of the filtration chamber 3 to supply air bubbles into the backwash water. This air blowing pipe 13 is connected to an air inlet nozzle 17. The hollow fiber membrane module 5 is covered with a protective tube 16. Reference numeral 20 denotes a liquid level needle as a liquid level detection device for detecting the water level of backwash water set in the area from the upper end to the lower end of the hollow fiber membrane module structure installed vertically in the filtration chamber 3. be. This liquid level needle 20 communicates with the filtration chamber 3 and is connected to an upper mounting seat 2 led out from the end surface of the tube plate 2.
1 and the lower mounting seat 18 led out from the filtration chamber 3 below the lower end of the hollow fiber membrane module 5.
Mounted via. Therefore, the liquid level needle 20 accurately indicates the position of the backwash water level at any position along the entire length of the hollow module structure.

Inflow port 18 located inside the closed container 1 of the lower mounting seat 18
As shown in an enlarged view in FIG. 2, a T-tube 24 is connected to the tube a, the upper end of which is closed and the lower end of which is open.

An air hole 23 is provided at the upper end of this T-shaped tube 24. By connecting this T-shaped pipe 24, the cladding 22 floating in the filtration chamber 3 is prevented from flowing into the lower mounting seat 18, and the inflow port 18a is not clogged. Note that the air handling hole 23 is provided to prevent the air from flowing toward the liquid level needle 20 side when air is mixed in, and to make it easier to flow out into the filtration chamber 3.

According to this embodiment, crud etc. do not flow into the lower mounting seat 18 and the flow path leading to the liquid level needle, so that the liquid level can be measured accurately.

3 and 4 are partial cross-sectional views showing other examples of the inlet portion 18a of the lower mounting seat 18 of the liquid level needle 20. FIG.

FIG. 3 shows an example in which the end of the inlet portion 18a is formed into a tapered cut surface 18b that is long at the top and short at the bottom.

In this example, the cladding floating in the container 1 is attached to the lower mounting seat 1.
It does not flow directly into 8.

In addition, FIG. 4 shows that an elbow-shaped member 25 with an opening at the lower end is connected to the inlet port 18a, and air holes 2 are formed on the upper surface of the member 25.
3 is shown. In this example, as in the example shown in FIG. 2, it is possible to prevent the cladding 22 from accumulating and clogging at the inlet port 18a.

Therefore, the liquid level in the filtration chamber 3 can be accurately measured with the liquid level needle 20.

[Effects of the Invention] According to the present invention, the inlet part of the lower mounting seat of the liquid level gauge is formed in a shape that prevents cladding from flowing into the inlet part, so that clogging does not occur in the inlet part, so the liquid level in the filtration chamber can be accurately determined. can be measured.

In addition, since the liquid level in the filtration chamber can be accurately measured, partial backwashing operations are possible, allowing the entire hollow fiber membrane module to be uniformly and efficiently backwashed.

Therefore, the service life of the hollow fiber membrane itself is extended, running costs are reduced, and continuous operation over a long period of time becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the hollow fiber membrane type filtration device according to the present invention, FIG. 2 is an enlarged sectional view showing the lower mounting seat in FIG. 1, and FIGS. 3 and 4 are 5 is a sectional view showing other examples of the lower mounting seat, FIG. 5 is a sectional view showing a conventional hollow fiber membrane type filtration device, and FIG. 6 is an enlarged sectional view showing the lower mounting seat in FIG. 5. . 1... Sealed container 3... Filtration chamber 4... Processing liquid chamber 5... Hollow fiber membrane module 6... Hollow fiber membrane 7... Module fixing part 8.9... Outer periphery 7 Lange 10... Raw solution inlet nozzle 11... Water collection pipe, 12... Processing liquid outlet nozzle 13.
...Air blow-off pipe, 14...Backwash water outlet nozzle 15...
・Vent, 16...Protective cylinder 17...Air inlet nozzle 18...Lower mounting seat, 19...Main valve 20...Liquid level gauge, 21...Upper mounting seat 23...Air vent Hole, 24
...T tuition fee (8733) Agent Patent attorney Yoshiaki Inomata (1 idiot) Figure 1 Figure 2 Figure 3 Figure 6 Figure 4

Claims (1)

[Claims] The inside of the airtight container is divided into a filtration chamber and a processing liquid chamber by a tube plate, and a hollow fiber membrane module structure is vertically disposed in the filtration chamber from the tube plate, and the hollow fiber membrane module structure is connected from an upper end to a lower end. In a hollow fiber membrane filtration device equipped with a liquid level gauge that detects the water level of backwash water set in an area ranging from A hollow fiber membrane type filtration device characterized in that it is formed in a shape that prevents the inflow of particles.