JPH0456655B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a filtration device, particularly a hollow fiber membrane filtration device using a hollow fiber membrane filter.

[Technical background of the invention and its problems] In nuclear power plants, generation, suppression, and removal of corrosion products are carried out as radiation reduction measures. For example, filtration devices are used to separate and remove suspended matter present in radioactive waste fluid generated in nuclear power plants and condensate water in primary cooling systems. Conventionally, such a filtration device uses a precoated filter such as a powdered ion exchange resin, a flat membrane filter such as filter paper or a filter cloth membrane membrane, and a method using a filter made of crystalline metal, ceramic, etc. Methods such as using empty tube filters have been used.

However, filtration methods that use powdered ion exchange resin generate large amounts of resin waste, and methods that use flat membrane filters or hollow tube filters require large circulation flow rates, making the system configuration difficult. There is a problem that it becomes complicated and the equipment cost increases. Furthermore, there were other problems such as secondary waste being generated, filtration efficiency being low, and space and equipment costs increasing.

Therefore, recently, a method of separating and removing suspended matter in waste liquid using a hollow fiber membrane filtration device using a hollow fiber membrane filter has been adopted. Figure 1 shows
This figure shows a schematic configuration diagram of a prior art hollow fiber membrane filtration device of the present invention, and as shown in the figure, a substantially U-shaped hollow fiber membrane filter 2 is attached and fixed to a partition plate 3 provided in a container body 1. are doing. A waste liquid supply pipe 4 is provided at the inlet on the side of the container body 1, and a waste liquid supply pipe 4 is provided at the inlet at the upper end of the container body 1 after the supplied waste liquid is filtered by the hollow fiber membrane filter 2. A processing liquid discharge pipe 5 for discharging the processing liquid is provided. Further, the discharge pipe 5 is provided with a gas supply pipe 6 which branches from the discharge pipe and supplies pressurized gas for backwashing to the hollow portion of the hollow fiber membrane filter 2. Furthermore, a concentrated waste liquid discharge pipe 7 is provided at the outlet at the lower end of the container main body 1 to discharge concentrated waste liquid after discharging the processing liquid. Further, an overflow pipe 8 is arranged below the mounting position of the partition plate 3. Each of the pipes has an on-off valve 9, 10, as shown in the figure.
11, 12, and 13 are provided.

However, in such a hollow fiber membrane filtration device,
While the waste liquid is flowing into the container body 1 through the waste liquid supply pipe 4 at a constant pressure, filtration is performed until the filtration differential pressure of the hollow fiber membrane filter 2 reaches a predetermined value.During this time, the treated liquid is It is discharged from the discharge pipe 5.

Then, pressurized gas is supplied from the gas supply pipe 6 to the hollow part of the hollow fiber membrane filter 2, and the suspended matter adhering to the outside of the hollow fiber membrane filter 2 is peeled off and the concentrated waste liquid is discharged. After that, new waste liquid is supplied from the waste liquid supply pipe 4 into the container body 1, and the above-described filtration of the waste liquid is repeated.

By the way, it is known that the space in which a waste liquid filtration device can be installed is limited due to the location conditions of a nuclear power plant, and it is also known that a vertically elongated container body is structurally more advantageous than a horizontally elongated one. However, in the prior art hollow fiber membrane filtration devices, the inner diameter is 0.1~
Since a hollow fiber membrane filter with a small thread diameter such as 0.5 mmφ is used, its length was thought to be limited to about 1 m in terms of pressure loss and other factors. Therefore, a waste liquid filtration device requires a considerable amount of space, and in order to reduce this space as much as possible, it has been desired to develop a hollow fiber membrane filtration device with a vertically elongated structure as described above.

[Object of the invention] The present invention has been made in view of the above circumstances, and
The purpose is to provide a compact hollow fiber membrane filtration device that is suitable for installation in a limited space, has high filtration efficiency, and is compact.

[Summary of the Invention] In order to achieve the above object, the present invention provides a pneumatic container body having at least an inlet and an outlet, a partition plate provided in the main body of the container, and a large number of air holes provided on the outside of the water intake pipe. The pipes are arranged in a vertical direction, and at least both ends of the water intake pipe are fixed to the end member in an open state, and a large number of hollow fiber membrane filters are arranged around the water intake pipe and the pneumatic water pipe. A hollow fiber membrane module is provided in which both ends of a membrane filter are adhesively fixed to the end member in an open state, and one or more hollow fiber membrane modules are connected in series and the end member serving as an end plug is connected to the end member. This invention relates to a hollow fiber membrane filtration device fixed to a partition plate. The water intake pipe and the pneumatic feed pipe are configured as double pipes or arranged in parallel, and the hollow fiber membrane modules are connected in series through spacers.

[Embodiments of the invention] Embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows a schematic diagram of an embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals and will be explained. As shown in the figure, a module assembly in which two hollow fiber membrane modules 17 are vertically connected in series with fixing fittings 18 is attached and fixed to a partition plate 19 provided in the container body 14. A waste liquid supply pipe 4 is provided at the inlet on the side of the container body 14, and a waste liquid supply pipe 4 is provided at the upper end of the container body 14, and the waste liquid is filtered through the hollow fiber membrane module 17 at the outlet at the upper end of the container body 14. A processing liquid discharge pipe 5 for discharging the processing liquid is provided. Further, a gas supply pipe 6 is provided which branches from the discharge pipe 5 and supplies pressurized gas for backwashing to the hollow fiber membrane module 17. Container body 14
A concentrated waste liquid discharge pipe 7 for discharging the concentrated waste liquid after discharging the processing liquid is provided at the outlet at the lower end of. Further, an overflow pipe 8 is arranged below the mounting position of the partition plate 19. Furthermore, an expected supply pipe 15 for supplying pressurized gas is also arranged below the hollow fiber membrane module assembly. Each of the pipes has on-off valves 9 and 1 as shown in the figure.
0, 11, 12, 13, and 16 are provided.

Therefore, the hollow fiber membrane module 17 of this example
As shown in FIG. 3, both ends of the water intake pipe 20 are fixed to an end member 23 (hereinafter referred to as an end plug) or an end member 24 in an open state, and an air hole (not shown) is provided on the outside of the water intake pipe 20. A pneumatic feed pipe 21 is provided. In other words, a double pipe consisting of the water intake pipe 20 and the pneumatic feed pipe 21 is formed. Also, as can be seen from the figure, both ends of the water intake pipe 20 are open and the end plugs 2
3 or the end member 24, while the pneumatic conduit 21 is fixed to the end member 24 in an open state but to the end plug 23 in a closed state. Furthermore, this water intake pipe 20 and the pneumatic feed pipe 21
A large number of linear hollow fiber membrane filters 22 with micropores formed on the outer periphery are arranged around the hollow fiber membrane filter 22, and the hollow fiber membrane filters 22 are connected to the end plug 23 and the end member 24.
It has a structure in which it is adhesively fixed in an open state.

Hollow fiber membrane module 17 configured in this way
A plurality of (two in the figure) are fixed vertically with fixing fittings 18 via spacers 25 as shown in the figure to constitute a hollow fiber membrane module assembly. The uppermost end member, ie, the end plug 23 of such a hollow fiber membrane module assembly forms a wide end so as to be connected to the partition plate 19, and a spacer 27 is provided at the lowermost end of this modular assembly. Place the fixing bracket 26
Fix it with. As shown in FIG. 4, the spacer 25 has a cross-shaped water intake hole 28 located approximately in the center of the spacer 25, and an air hole 29 having a vertical opening at a location that does not intersect with the water intake hole 28.
is formed. In the figure, there are two air holes 29, but there may be more. The only difference between the spacer 27 and the spacer 25 is that the cross-shaped hole formed at the lower end of the water intake hole 28 is closed. Also, at least between the end plug 23 and the partition plate 19 and between the end member 24 and the fixing metal fitting 18.
Alternatively, a sealing material 30 is provided between the waste liquid and the processing liquid to prevent the waste liquid from mixing with the processing liquid. In addition, in the figure, the end member 24 and the spacer 25 or 27
A sealing material 30 is also provided between the two.

Next, the filtration action of this embodiment will be explained.

The waste liquid that has flowed in through the inlet passes through the hollow fiber membrane filter 22 from the outside of the hollow fiber membrane filter 22, and only water permeates into the inside of the hollow fiber membrane filter 22, and the dispersed solids in the waste liquid are captured on the surface of the hollow fiber membrane filter. Solid-liquid separation is performed by this. The water that has permeated into the hollow fiber membrane filter 22 is transferred to the hollow fiber membrane filter 22.
Through the hollow part, one part is taken out onto the end plug 23, and the other part flows into the gap between the fixture 18 and the spacer 25 and between the fixture 26 and the spacer 27, and flows into the water intake hole 28 of the spacer 25, 27. It passes through the water intake pipe 20, is taken out onto the end plug 23, and is further discharged outside the apparatus through the treatment discharge pipe 5 (third
The solid line arrow in the diagram indicates the direction in which waste liquid or water flows). In the filtration operation, the waste liquid is caused to flow into the container body 14 through the waste liquid supply pipe 4 at a constant pressure, and filtration is performed until the filtration differential pressure of the hollow fiber membrane filter 22 reaches a predetermined value.

Thereafter, when the filtration differential pressure of the hollow fiber membrane filter 22 becomes less than a predetermined value, the filtration operation is stopped and the hollow fiber membrane filter 22 is backwashed.
This backwashing is performed in reverse to the filtration operation. That is, air is pumped from the inside of the hollow fiber membrane filter 22 to the outside of the hollow fiber membrane filter 22 through the gas supply pipe 15 from a gas supply source (not shown), and the dispersed solid matter adhering to the outer surface of the hollow fiber membrane filter 22 is removed from the hollow fiber membrane filter 22. The air bubbles generated from the micropores formed on the outside of the air bubbles are used to clean the air (the dotted line arrow in Figure 3 indicates the direction in which air flows). Further, the pressurized air enters the pneumatic feed pipe 21 through the air holes 29 of the spacers 25 and 27, and is released as bubbles from the air holes provided on the outer periphery of the pneumatic feed pipe 21. This allows the hollow fiber membrane filter 22 to be vibrated by the bubbles from the outside, thereby enhancing its cleaning effect. When the cleaning is completed, new waste liquid is supplied from the waste liquid supply pipe 4 into the container body 14, and the waste liquid is repeatedly filtered as described above.

In the above description, the water intake pipe and the air pressure feed pipe are double pipes, but they may be placed side by side, and air or water for cleaning may be supplied from above the hollow fiber membrane module. Furthermore, it goes without saying that even one hollow fiber membrane module can perform the filtration action of waste liquid. In the above example, waste liquid from a nuclear power plant is mainly explained.
It goes without saying that the present invention can be applied to solid-liquid separation of waste liquids or liquids containing suspensions in other plants.

[Effects of the Invention] According to the present invention, even if a plurality of hollow fiber membrane modules are connected in series, the same performance as a single hollow fiber membrane filter can be obtained without being affected by the pressure drop of the hollow fiber membrane filter. The hollow fiber membrane filtration device can have a vertically elongated structure. As a result, space can be used effectively. Furthermore, the water intake pipe is installed to increase the water intake effect, and a pneumatic feed pipe with air holes is installed, so by blowing out air bubbles or water during cleaning, a large number of hollow fiber membrane filters can be cleaned in a short time. can be done.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a prior art hollow fiber membrane filtration device of the present invention, Figure 2 is a schematic configuration diagram of an embodiment of the present invention, and Figure 3 is the hollow fiber membrane module in Figure 2 and its combination. A cross-sectional view for explaining the body, Figure 4, is
FIG. 3 is a perspective view of a spacer. 4... Waste liquid supply pipe, 5... Processed waste liquid discharge pipe, 7
... Concentrated waste liquid discharge pipe, 14 ... Container body, 15 ...
...Gas supply pipe, 17...Hollow fiber membrane module, 1
8, 26...Fixing metal fittings, 19...Partition plate, 20...
... Water intake pipe, 21 ... Pneumatic feed pipe, 22 ... Hollow fiber membrane filter, 23 ... End plug, 24 ... End member, 2
5, 27...Spacer, 30...Sealing material.

Claims (1)

[Scope of Claims] 1. A container body provided with at least an inlet and an outlet, a partition plate disposed inside the container body, and a pneumatic feed pipe having a large number of air holes on the outside of the water intake pipe. and fixing at least both ends of the water intake pipe to the end member in an open state, further arranging a large number of hollow fiber membrane filters around the water intake pipe and the pneumatic feed pipe, and leaving both ends of the hollow fiber membrane filters open. a hollow fiber membrane module that is adhesively fixed to the end member in a state where one or more hollow fiber membrane modules are connected in series, and the end member that serves as an end plug is fixed to the partition plate. A hollow fiber membrane filtration device characterized by: 2. The hollow fiber membrane filtration device according to claim 1, wherein the water intake pipe and the pneumatic feed pipe are double pipes or arranged in parallel. 3. The hollow fiber membrane filtration device according to claim 1, wherein the hollow fiber membrane modules are connected in series via spacers.