JPH0437620Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a non-auxiliary material type filtration device suitable for condensate purification systems of nuclear power plants, etc. This invention relates to a hollow fiber membrane type filtration device with improved properties.

(Prior Art) In boiling water nuclear power plants, measures are being taken to prevent various types of crud from being brought into the reactor in order to reduce radiation exposure and maintain the integrity of the fuel. As part of these countermeasures, recent nuclear power plants have installed filters pre-coated with powdered ion exchange resin as prefiltration devices in addition to mixed bed ion exchange towers to improve crud removal performance in condensate purification systems. ing.

However, since this type of prefiltration device generates a large amount of used ion exchange resin as secondary radioactive waste, there is room for improvement in the storage, processing, and operating costs of waste resin. In other words,
There is a need for the development of a non-auxiliary material type prefiltration device that generates less secondary radioactive waste, requires less space, and has low running costs.

In response to these demands, attempts have recently been made to use hollow fiber membrane filters, which are used in radioactive waste treatment facilities, as non-auxiliary prefiltration devices for condensate purification systems.

FIG. 3 shows a conventional hollow fiber membrane type condensate filtration device of this type, which will be explained below.

In FIG. 3, reference numeral 1 denotes a cylindrical container having a closed structure and partitioned from a container lid 2 by a support plate 3. As shown in FIG. An inlet pipe 4 and a drain pipe 5 for the liquid to be treated are provided on the bottom plate of the container 1, and a vent pipe 6 is provided on the upper side surface. The lid 2 is provided with a processing liquid outflow pipe 7 which also serves as a backwashing air inflow pipe.

Inside the container 1, a hollow fiber membrane module structure 9 is arranged, which is a bundle of a large number of hollow fiber membranes 13 whose upper ends are fixed to the support plate 3 via a presser plate 8. A protection tube 10 is disposed in the housing. The lower end of the protective tube 10 is connected to the connecting portion 1
They are interconnected via 1. Further, below the module structure 9, there are a number of nozzles 12A.
Air piping is provided with a

In the hollow fiber membrane type filtration device configured as described above, the liquid to be treated flows into the container 1 from the inflow pipe 4 and then into the protection pipe 10 . Then, since the hollow fiber membrane 13 is a type of pulp filter, only water of the liquid to be treated passes through, and solid substances such as crud adhere to the surface of the hollow membrane 13 and are separated and removed. Hollow fiber membrane 13
The water that has permeated inside passes through the inside of the module structure 9 and flows to the upper side of the support plate 3 as purified water (processing liquid). Then, this purified water is discharged to the outside from the processing liquid outflow pipe 7 of the lid 2.

When this condensate filtration device performs condensate filtration operation for a long time, many foreign substances such as crud remaining after filtration adhere to the surface of the hollow fiber membrane 13.
The filtration performance of No. 3 decreases. Therefore, the hollow fiber membrane 13
A backwash operation is performed at regular intervals to restore the filtration performance of the filter.

During this backwashing operation, a bubbling operation is also performed in parallel. In this backwashing operation, first, high pressure air is injected into the container 1 from the processing liquid outflow pipe 7,
The purified water in the lid 2 is made to flow back from the inside of the hollow fiber membrane 13 to the outside. At this time, the vent pipe 6 is opened to drain the water that has increased due to backflow, and the air pipe 1
Air is flowed out from the second nozzle 12A to generate air bubbles in the protective tube 10 and vibrate the hollow fiber membrane 13. Air bubbles in the protection tube 10
The air is discharged to the outside of the protective tube 10 from the hole provided in the upper part of the protective tube 10, thereby preventing the inside of the protective tube 10 from being filled with air.

Through this backwashing operation, crud adhering to the surface of the hollow fiber membrane 13 is removed, the hollow fiber membrane 13 recovers its normal filtration performance, and the liquid to be treated in the container 1 is discharged from the drain pipe 5 and drained. It is processed.

(Problems to be solved by the invention) As mentioned above, in the conventional hollow fiber membrane type filtration device, the inflow pipe 4 that flows the liquid to be treated into the hollow fiber membrane 13 is located on the bottom plate at a position away from the center line of the container 1. provided,
Further, a drain pipe 5 is provided on the bottom plate directly below the container 1 along the center line. Further, the liquid to be treated flows into the hollow fiber membrane module structure 9 through the inflow pipe 4.
A buffer plate 14 is provided on the overhanging portion of the inflow pipe 4 to prevent direct impact. Therefore, the liquid to be treated flowing in through the inflow pipe 4 is diverted from the opening provided on the lower side of the buffer plate 14 and flows out into the container 1.
flows upward along the inside of the

However, since the inflow pipe 4 is not located at the center of the container 1, a biased flow occurs at the lower ends of the container 1 and the protection tube 10, and the hollow fiber membrane module structure 9 receives uneven and different flow rates of the liquid to be treated. There are issues that arise.

The present invention was made to solve the above problems, and aims to provide a hollow fiber membrane type filtration device that improves the uniformity of the liquid to be treated flowing into the hollow fiber membrane module structure and reduces the size of the device. be.

[Structure of the idea]

(Means for solving the problem) The present invention has a plurality of hollow fiber membrane module structures vertically installed in a container via a support plate, a vent pipe is connected to the upper side of the container, and the liquid to be treated is removed. An inflow pipe and a drain pipe are attached to the bottom plate of the container, and an outflow pipe for the processing liquid is attached to the container lid, and a portion of the inside of the container between the opening of the inflow pipe for the liquid to be treated and the lower part of the hollow fiber membrane module structure is attached. This is a hollow fiber membrane type filtration device with an annular baffle plate attached to the side.

(Operation) The liquid to be treated flows into the container from an inflow pipe attached to the bottom plate of the container, and flows out near the annular baffle plate in the lower part of the container. The baffle plate uniformly disperses the liquid to be treated, changes the flow direction upward, and flows into the hollow fiber membrane module structure. Cruds in the liquid to be treated adhere to the surface of the hollow fiber membrane of this modular structure, and the treated liquid that has passed through the hollow fiber membrane flows out of the container from the outflow pipe. Therefore, the flow of the liquid to be treated to each hollow fiber membrane can be made uniform without reducing the flow rate due to the deflected flow of the liquid to be treated.

(Example) 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. In FIG. 1, the same parts as in FIG. 3 are given the same reference numerals, and explanations of the overlapping parts are omitted.

The difference between the present invention and the conventional example is that, as is clear from FIG. This is because the annular baffle plate 15 is provided. The annular baffle plate 15 is provided with a large number of small holes 16, as shown in FIG.

In the hollow fiber membrane filtration apparatus having the above structure, the liquid to be treated is guided from the inflow pipe 4 to the buffer plate 14, flows into the container 1, and collides with the baffle plate 15. The flow direction of the liquid to be treated is changed by the baffle plate 15 and guided toward the air pipe 12, while
The upward flow is dispersed by a large number of small holes 16,
It flows into the hollow fiber membrane type module structure 9 while flowing near the air pipe 12 . Crads in the liquid to be treated adhere to the surface of the hollow fiber membrane 13 in the module structure 9, and the treated liquid that has passed through the hollow fiber membrane 13 flows out of the container 1 from the outflow pipe 7. At this time, the deflected flow of the liquid to be treated is dispersed into a uniform flow and guided to each hollow fiber membrane 13.
The downward flow velocity at the lower end becomes almost uniform, and the flow of the liquid to be treated to the hollow fiber membrane 13 can be made equal without causing a decrease in the flow rate.

In particular, by providing the baffle plate 15, the container 1
This has the effect of dispersing and rectifying the flow of the liquid to be treated that has flowed into the chamber. Further, as shown in FIG. 2, by providing small holes 16 in the baffle plate 15 below the hollow fiber membrane module, it is possible to enhance the dispersion effect of the flow of the liquid to be treated and improve the drain efficiency. . Note that the shape, thickness, mounting angle, etc. of the baffle plate 15 can be arbitrarily selected as necessary. Moreover, one or more baffle plates 15 can be used, and their arrangement can also be arbitrarily selected.

[Effect of idea]

According to the present invention, the rectifying effect of the liquid to be treated is increased by providing a baffle plate on the lower inner peripheral surface and bottom of the container. This makes the flow of the liquid to be treated uniform, and the amount of crud etc. removed by the hollow fiber membrane becomes constant. Therefore, it is possible to extend the backwashing period of the hollow fiber membrane, and accordingly, the life of the hollow fiber membrane can be extended. Further, by providing the baffle plate, the rectifying effect of the liquid to be treated can be increased, so the distance between the inflow pipe and the hollow fiber membrane module can be shortened. Therefore, the container becomes more compact, which not only reduces manufacturing costs, but also
Restrictions on transportation and installation are eased, and economic efficiency can be improved.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view showing an embodiment of the hollow fiber membrane type filtration device according to the present invention, Figure 2 is a cross sectional view seen from the bottom of Figure 1, and Figure 3 is a conventional hollow fiber membrane type filtration device. It is a longitudinal cross-sectional view showing a filtration device. 1... Container, 2... Lid, 3... Support plate, 4...
Inflow pipe, 5...Drain pipe, 6...Vent pipe, 7...
... Outflow pipe, 8 ... Holding plate, 9 ... Hollow fiber membrane module structure, 10 ... Protection tube, 11 ... Connection part,
12...Air piping, 13...Hollow fiber membrane, 14...
Buffer plate, 15... baffle plate, 16... small hole.

Claims (1)

[Claims for Utility Model Registration] 1. A plurality of hollow fiber membrane module structures are installed vertically in a container via a support plate, a vent pipe is connected to the upper side of the container, and an inlet pipe and a drain pipe for the liquid to be treated are connected to the upper side of the container. A pipe is attached to the bottom plate of the container, an outflow pipe for the processing liquid is attached to the container lid, and an annular baffle plate is installed on the side surface of the container between the opening of the inflow pipe for the liquid to be treated and the lower part of the hollow fiber membrane module structure. Hollow fiber membrane type filtration device with attached. 2. The hollow fiber membrane type filtration device according to claim 1, wherein the baffle plate has a large number of small holes.