JPS62244407A - Filter - Google Patents

Abstract

PURPOSE:To furnish a membrane module with interchangeability with an element of existing precoating filter by exchanging a filter assistant precoating element with a hollow yarn membrane module constituted with a hollow yarn membrane provided on the outer circumference of an inner cylinder and adding a module fixing plate. CONSTITUTION:A hollow yarn membrane module consisting of a hollow yarn membrane 61 and a protecting cylinder 62 installed cylindrically around an inner cylinder 60 is hung down from a module fixing plate 54 inserted between a trunk plate of the existing precoating filter and a cover plate 53, and fixed with a module pressing plate 55. The lower end of module is sealed with its raw liquid and treating water side with a packing 66 and an adaptor cover 67 when the inner cylinder 60 is inserted in an adaptor. Raw liquid such as condensate introduced from a raw liquid inlet tube in the lower section of filter column is passed from the outside to inside of hollow yarn membrane to remove clad. The treating liquid is guided from inside the membrane to the upper section, and after coming out into the upper part of the fixed plate 54, passes the inner cylinder 60 and returned from a treating water outlet at the lower section of filter column into the condensate system or the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filtration device for treating a stock solution containing corrosion products, and in particular, to a filtration device for treating an undiluted solution containing corrosion products. The present invention relates to a filtration device equipped with a hollow fiber membrane module suitable for use as a hollow fiber membrane filter.

[Conventional technology]

Conventional nuclear reactors), especially boiling water reactors,
The steam flowing out from the reactor pressure vessel, which has the configuration shown in the figure and is equipped with a reactor coolant purification system, is transferred to the high pressure turbine 2. It flows into the condenser 5 via the moisture separator 3 and the low-pressure turbine 4, and is condensed in the condenser 5 to become condensate. The low pressure turbine 4 is connected to a feedwater heater 7 via a bleed pipe, and the feedwater heater 7 is connected to a condenser 5 via heater drain pipes 8 and 9.

Here, condenser 5. Corrosion products generated in the bleed pipe 6, feed water heater 7, etc. become impurities in the condensate. This condensate containing impurities is removed by a low-pressure condensate pump into a condensate filtration device 10. The condensate is sent to the condensate desalination equipment 1 and subjected to filtration and salt treatment. The condensate from which impurities have been removed flows into the reactor pressure vessel 1 via the feedwater heater 12, the reactor feedwater pump 13, and the feedwater heater 7, and thereafter, the condensate is repeatedly circulated in the same manner. Ru.

Also in thermal power plants, corrosion products generated in boilers, feed water heaters, etc. are collected in a condenser and filtered in a condensate filtration device and a condensate desalination device.

For example, in the case of condensate filtration equipment installed to remove corrosion products generated in thermal power plants and nuclear couplers as mentioned above, a pre-coated type has traditionally been adopted, and the structure shown in Figure 5 has been changed. The stock solution inlet pipe 20. A body plate 22 and a lid plate 23 are connected to the treated water outlet pipe 21, a flange bolt 24 is connected between the body plate 22 and the lid plate 23, and inside the container there are an element 25, a tube sheet 26 for holding the element, and a stock solution. It is composed of a rectifying plate 27 for rectifying the current.

The elements are now mounted as shown in FIG.

That is, the element is inserted into the lower element adapter 70 and sealed with the packing 71. To prevent the element from coming off from this adapter, the upper spring 72
By pressing the element downward, the sealing performance between the adapter 70 and the gasket 71 is improved.

The stock solution containing corrosion products is introduced into the tower through the stock solution pipe 20, and after being filtered through the filter aid layer 28 pre-coated on the surface of the Niremen 1-25, the stock solution is passed through the treated water outlet pipe 21-25. It is then returned to the condensate system.

That is, the stock solution passes through the pre-coated filter medium layer 73, and corrosion products are removed on this surface. The treated water passes through the element 74, passes through the inside of Niremen, and is led to the lower part of the column.

Here, the filtration tower is controlled by the tower differential pressure, and when the specified pressure difference is reached, backwashing is performed assuming that the filter aid on the surface of the element 25 has replenished the specified amount of corrosion products. , the filter aid and the trapped corrosion products are removed from above the element 25 and discharged to the outside of the column.

The filter aid and corrosion products discharged from this tower are concentrated in a waste treatment device and then incinerated or canned in drums.

In the backwashed filtration tower, the surface of the element 25 is newly pre-coated with a filtering aid, and the filtration tower is again subjected to the undiluted solution treatment.

The pre-coated type filtration tower described above has been used in many thermal power plants and nuclear couplers, but since it requires a filtration aid, it generates a large amount of waste. There were other matters to consider, such as the need for appropriate equipment.

For this reason, in recent years for thermal power and nuclear power plants, hollow fiber membrane type filter towers have been developed as non-filter filters that do not use filter aids, and there is a tendency for them to be adopted in actual plants.

The hollow fiber membrane filter has the structure shown in FIG. 6, and includes a body plate 31 that connects the raw solution inlet pipe 30, a cover plate 33 that connects the treated water outlet pipe 32, and a flange that connects the body plate 31 and the cover plate 33. The container is comprised of a bolt 34 and a module fixing plate 36 to which a module 35 supported by a body plate 31 and a lid plate 33 is attached inside the container.

The stock solution containing corrosion products is introduced into the tower through the stock solution inlet pipe 30 and filtered by the module 35 . FIG. 7 shows the structure of the module 35. The stock solution is introduced into the module through an upper stock solution inlet 40 and a lower stock solution port 41. A large number of hollow fiber membranes each having a hollow center are provided in the module, and the stock solution is guided to the hollow portion in the center of the fiber through small diameter holes on the surface of the hollow fiber membranes. At this time, the corrosion products in the raw solution cannot pass through the small diameter hole, and only water is guided to the hollow part at the center of the yarn.

The treated water passes through the central cavity of the hollow fiber membrane, is guided to the top of the tower, and is returned to the condensate system via the treated water outlet pipe 32.

Here, the filtration tower captures a specified amount of corrosion products on the surface of the hollow fiber membrane in the module 45, and then performs backwashing and discharges the corrosion products captured on the membrane surface to the outside of the tower.

In other words, the hollow fiber membrane filter has advantages over the pre-coated filter described above, such as a reduction in the amount of waste and the need for Glyco-1 equipment, since it does not require a filter aid.

This hollow fiber membrane filter generally has an inlet for the raw solution at the bottom of the tower and an outlet for the treated water at the top of the tower, and has a module structure as shown in Figure 7, so it is similar to a conventional precoat type filter. It was not compatible with the filter element 27, which introduces the raw solution from the bottom of the column and sends out the treated water from the bottom of the column. Therefore, it has not been possible to change the conventional precoat type filter to a hollow fiber membrane filter by simple measures such as replacing the module.

Incidentally, related devices of this type include, for example, U.S. Patent No. 323177, U.S. Pat.
etc.

[Problem that the invention seeks to solve]

Regarding the conventional pre-coated filter and the recently developed hollow fiber membrane filter mentioned above, the function of filtering corrosion products in condensate is performed by an element or module installed inside the tower. So, they are the same. However, the compatibility between the elements of this pre-coated filter and the modules of the hollow fiber membrane filter has not been taken into account, and therefore the pre-coated filters in actual operation have already been replaced with hollow fiber membranes for the purpose of reducing the amount of waste. Even if they wanted to change to a membrane filter, the only option was to make major modifications such as replacing the tower.

An object of the present invention is to make the structure of the module that houses the hollow fibers (1) compatible with the elements of conventional pre-coated filters, so that it can be easily changed even in existing plants.

[Means for solving problems]

(1) Since the hollow fiber membrane module is basically a hanging type, II) a module fixing plate is inserted between the first plate and the cover plate to suspend the module.

(2) Seal the element adapter part of the inner tube sheet part with a packing.

(3) Since both the raw solution inlet and the treated water outlet are at the bottom of the tower, the condensate that passes through the membrane and is led to the second part of the tower is guided to the bottom of the tower by passing the inner cylinder through the center of the module.

This can be achieved by creating a hollow fiber membrane module that takes into account the following structural considerations.

[Effect]

The hollow fiber membrane module has an inner cylinder in the center and a hollow fiber membrane around the outer periphery of the inner cylinder. Since the hollow fiber membrane is a hanging type, a module fixing plate is inserted between the body plate and the lid plate.The stock solution is guided from the outer surface of the hollow fiber membrane inside the module to the center of the module and to the top of the tower. is guided to the lower part of the tower through the inner cylinder. This module structure allows the hollow fiber membrane module to be installed using the pre-coated filter element attachment part, and also allows the module fixing plate to distinguish between the raw solution side and the treated water side, allowing the tower to Since it is possible to change the pre-coated filter to a hollow fiber membrane filter without modification, the filter's ability to filter corrosion products from the stock solution, which is the purpose of the filter, will not be affected.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

Condensate containing corrosion products is introduced from the raw solution inlet pipe 50 at the bottom of the column, and is filtered through an element 51 installed inside the column.
The function and structure of returning treated water to the condensate system from the outlet pipe 52 at the bottom of the tower are the same as those of conventional pre-coated filters.

Here, the difference from the conventional Precor 1 type filter is that it has a hollow fiber membrane module structure that is compatible with the element 51.

Due to the characteristics of the fibers, the hollow fiber membrane module needs to be of a hanging type. Therefore, the module fixing plate 54 is inserted between the body plate 52 and the lid plate 5;

FIG. 2 shows details of the hollow fiber membrane module structure and its attachment portion.

The hollow fiber membrane module is composed of an inner cylinder 60, a hollow fiber membrane 61, a protection cylinder 62, and parts for attachment to the tower.

The hollow fiber membranes are arranged in a cylindrical shape around an inner cylinder 60 through which the treated water passes, and their upper ends are fixed with adhesive to separate the raw solution side and the treated liquid side and to fix the membranes to the module. In addition, the lower part is filled with adhesive in order to close the holes in the hollow fiber membrane and separate the raw solution side from the treated water side, and to prevent the fibers from becoming entangled. A protection tube 62 is provided on the outside of the hollow fiber membrane to protect the hollow fiber membrane 61. Here, the protection tube 62 is designed in consideration of transport handling. Since this protection tube 72 is attached while being installed in the tower, the upper stock solution is guided into the module from the hollow fiber membrane module inlet so that the stock solution flows into the outer surface of the hollow fiber membrane module 61. Flooding is removed by passing from the outer surface of the membrane to the inner surface. The removed processing liquid passes through the inside of the membrane, is guided to the upper part, exits to the upper part of the module fixing plate, passes through the inner cylinder 60, and is led to the lower part of the column.

To install the module inside the tower, remove the tower top cover plate 53 and remove the top cover plate 53.
A module fixing plate 54 is provided on the flange portion of No. 2. This fixing plate 54 has a hole for attaching the module, and the module is inserted into the tower through this hole, and the module lower attachment part is inserted into the adapter 56. The lower end of the module is the inner cylinder 6
0 is inserted into the adapter, and the packing 66 and adapter cover 67 seal the raw solution side and the treated water side. In other words, when the gasket 66 is partially pushed in, the spring 6
Press 5 upwards to seal the adapter cover 67 and seal 66.

On the other hand, the first end of the module is attached to the fixing plate 55 with a circle 68.
In order to secure the two parts of this module, it is sealed.
The module holding plate 55 is fixed to the module fixing plate 54 with bolts 57. After that, the lid plate 53 and the body plate 52 are fixed with bolts 57.

In this manner, by fixedly sealing the first end and the lower end of the module, vibration of the module during water flow and backwashing is prevented; the raw water side and the treated water side are sealed.

In the filtration process in this case, the undiluted solution is introduced into the column from the undiluted solution port 50 at the bottom of the column. The flow is rectified by a baffle plate 58 inside the tower, and the module is connected to the upper stock solution inlet 63 and the lower stock solution inlet 64.
The undiluted solution is guided into the module and is filtered by passing through the membrane from the surface of the hollow fiber membrane 61 to the cavity at the optical center. The filtered treated water is guided to the upper part of the tower through the hollow fiber membrane, sent to the lower part of the tower via the module cylinder 60, and returned to the condensate system through the treated water outlet 52.

According to this embodiment, the internal element is replaced with a hollow fiber membrane module without changing the structure of the conventional pre-coated filter, and the module fixing plate is inserted between the lid plate and the body plate, so that the hollow fiber membrane Because it can be used as a filter,
Existing filters can be easily replaced with hollow fiber membrane filters, which eliminates the need for filtration aids, waste aid materials, etc., and reduces waste generation and running costs.

FIG. 3 shows an example of application of the present invention, in which the module protection tube 62 is shaped like a net to facilitate introduction of the stock solution into the module. In other words, the introduction ports 63 to the upper and lower parts of the protective tube
Since it is conceivable that the introduction of the stock solution into the module becomes unbalanced if there are only 64 and 64, it is considered that the stock solution can be introduced into the module from any position.

Figure 8 shows a hollow fiber membrane with a two-stage structure.In order to make effective use of the membrane, a water collection section is provided in the center of the module, which separates the flow path for the processing liquid and reduces water flow resistance. This has been taken into consideration.

〔Effect of the invention〕

According to the present invention, when changing the filter processing method from a conventional precoat type filter to a hollow fiber membrane type filter, by making it compatible with the elements in the filter, (1) The pre-coated filter can be easily changed to a hollow fiber membrane filter.

(2) By using a hollow fiber membrane filter, no filtration aid is required, so the amount of waste generated and the running cost can be reduced.

(3) By providing an inner cylinder as a hollow fiber membrane module and arranging membranes around its outer circumference, it is possible to connect to the conventional treatment liquid outlet line at the bottom of the column.

etc'? There is a revenge

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a filter when changed to a hollow fiber membrane module according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of a hollow fiber membrane module according to an embodiment, and Fig. 3 is an explanatory diagram of a hollow fiber membrane module according to an embodiment of the present invention. Figure 4 is a system diagram of a boiling water type atomic couplant, Figure 5 is an explanatory diagram of a conventional pre-coated filter, and Figure 6 is an explanatory diagram of a hollow fiber membrane filter. , FIG. 7 is an explanatory diagram of a hollow fiber membrane module, and FIG. 8 is a diagram showing a hollow fiber membrane having a two-stage structure. 60...Module inner cylinder, 61...Hollow fiber membrane, 54
...Module fixing plate, 65...Spring, 66...
Packing, 68...O ring, 55...Module holding plate.

Claims (1)

[Claims] 1. In a filtration device that introduces a stock solution into a container and performs filtration processing, the element for precoating the filtration aid in the column is provided with an inner cylinder and a hollow hole around its outer periphery, without changing the structure of the column body of the conventional precoat type filter. A hollow fiber membrane module with a structure that can be easily changed to a hollow fiber membrane filter by replacing the hollow fiber membrane module equipped with a fiber membrane and adding a new module fixing plate, and the use of the module. A filtration device characterized by: