JPH0448198B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to condensate purification equipment, and particularly relates to a filter suitable for condensate purification equipment installed for the purpose of improving the quality of water supplied to nuclear power plants, etc. .

[Background of the invention]

Conventionally, in condensate purification equipment at nuclear power plants, etc., mixed bed desalination is used to improve water quality by removing insoluble substances (hereinafter referred to as cladding) and soluble substances (hereinafter referred to as ions) in condensate. Condensate purification equipment is used that combines a device or a super-assistant type filter and a mixed bed desalination device. However, due to the large amount of waste generated due to the regeneration of the ion exchange resin and backwashing of the super-assistant type filter, which are essential for continuous use of these devices, and the heat resistance properties of the ion exchange resin used, There were drawbacks, such as the efficiency of the system's thermal cycle being restricted because the temperature of the treated water was restricted.

In addition, if the wood is generated as secondary waste,
The problem was that it was difficult to process.

To overcome these drawbacks, various desalination devices,
Various improvements have been devised in the filter,
In particular, some non-auxiliary filters have been developed for the purpose of suppressing the generation of secondary waste.
Although some products have excellent removal performance for crud, they lack removal performance for ions, so they are not sufficient for condensate purification equipment such as nuclear power plants, which have strict water quality standards, and mixed bed desalination equipment and As a result, it has been impossible to provide equipment that completely overcomes the above problems.

[Purpose of the invention]

The object of the present invention is to reduce the amount of crud contained in condensate;
To provide condensate purification equipment that can remove impurities with different properties, such as ions, and that can minimize the amount of waste generated during regeneration and backwashing operations performed for continuous use of the equipment. be.

[Summary of the invention]

In order to achieve the above object, the present invention uses a porous fibrous or membrane-like thermally decomposable material that has an ion exchange base as a condensate purification filter for purifying condensate and has crud removal performance. It is characterized by the use of a filter which is bonded with ion exchange ability.

The filter of the present invention can remove not only crud but also ions in condensate.

Since the filter of the present invention has an ion exchange group bonded to a porous fibrous or membrane material, it can be regenerated using chemicals.
In addition, since the specific surface area can be increased compared to ion exchange resins, the ion exchange capacity per unit volume can be increased.As a result, the frequency of regeneration operations can be reduced compared to ion exchange resins, and the amount of waste generated during regeneration operations can be reduced. can do. Note that the ion exchange group can be bonded to a porous fibrous or membrane-like material using a treatment similar to the method for bonding the ion exchange group to a resin.

Furthermore, since the filter of the present invention does not use auxiliary materials, the amount of waste generated during backwashing operations can be greatly reduced.

Furthermore, since the filter of the present invention is made of a thermally decomposable material, when the filter is disposed of as waste, it can be significantly reduced in volume by incineration or the like.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows an example of a case where the condensate purification equipment according to the present invention is adopted in the schematic system configuration of a standard BWR plant.

The steam generated by the atom 1 drives the high pressure turbine 2 and the low pressure turbine 3, and then passes through the condenser 4.
It is cooled at The cooled condensate is transferred by a condensate pump 5, passes through an air extractor 6, and is supplied to the condensate purification equipment 7 introduced in the present invention. In the condensate purification equipment 7, crud and ions contained in the condensate after the reactor 1 are removed, and the purified condensate is returned to the reactor 1 via the low-pressure feedwater heater 8 and the high-pressure feedwater heater 9. Supplied.

As mentioned above, the condensate purification equipment 7 according to the present invention can obtain stable performance even at higher temperatures than the conventional mixed bed desalination equipment, etc. Therefore, the condensate purification equipment 7 is shown in FIG. The first position, not the position in the indicated lineage.
Low-pressure feed water heater 8 and high-pressure feed water heater 9 shown in the figure
It is also possible to place it in between.

FIG. 2 shows the system configuration of the condensate purification equipment according to the present invention. Condensate entering from the condensate inlet 4 of the ion clad filter 3 passes through the material 10,
Here, after the cruds and ions contained therein are removed, the condensate is discharged from the condensate outlet 5. As the ion cladding filter 3 is used, cladding and ions accumulate in the material 10 formed therein. The increase in the physical differential pressure of the material 10, mainly due to crud, is monitored by a differential pressure gauge 8, while the decrease in the ion exchange capacity of the material 10, mainly due to ions, is monitored by a conductivity meter installed downstream of the condensate outlet 5. Monitored by 9. In order to ensure performance stability of the material 10 during long-term use, when either the differential pressure gauge 8 or the conductivity meter 9 rises to a predetermined value, the material 10 is regenerated or backwashed. The regeneration operation can be carried out by separately injecting acid and alkali into the ion-clad filter 3 from the regeneration acid tank 1 and the regeneration loading tank 2, thereby activating the ion exchange ability of the material 10.
On the other hand, the backwashing operation can be carried out by supplying pressurized air stored in the pressurized tank 11 to the ion clad filter 3 and creating a flow in the material 10 in the opposite direction to the water sampling during normal operation.

The waste liquid generated by the regeneration or backwashing operation is collected in a waste liquid receiving tank 6, and is further transferred to a downstream processing facility by a transfer pump 7.

The above embodiment has the following effects.

Due to the characteristics of the material introduced in this invention, in addition to high removal performance against crud due to the physical property of porosity, it also has high removal performance against ions due to the chemical property of ion exchange ability attached to the material. It is possible to obtain satisfactory performance for both cladding and ions using a single device.

In addition, when compared with the mixed bed desalination equipment used in conventional condensate purification equipment, the physical property of the material's porosity mentioned above has an extremely effective chemical property of ion exchange capacity. In order to act,
In the regeneration operation performed when the ion exchange capacity of the device reaches saturation during use, it is sufficient that the amount of acid and alkali required is 1/10 or less of the equivalent ion load over the history of use of the device. It is.
Therefore, in the long run, it becomes possible to significantly reduce the amount of chemicals required for regeneration, and at the same time, the amount of secondary regeneration waste liquid is also reduced proportionally. In particular, recycled waste fluid generated from condensate purification equipment at nuclear power plants has radioactivity and requires a great deal of effort to process, so the present invention is expected to have an extremely large effect in reducing recycled waste fluid. Ru.

Furthermore, the improved molded material, which is the main component of the present invention, is superior to that of conventional ion exchange resins in terms of thermal stability of the ion exchange group fixed in the material, which is the basis of its ion exchange ability. Due to this feature, it can demonstrate performance even under higher temperature conditions compared to conventional mixed bed desalination equipment that uses ion exchange resins or filters that use powdered resin as a supporting material. Because of this feature, for example, when installing the equipment introduced in this invention in place of the conventional mixed bed desalination equipment in the condensate purification equipment of a nuclear power plant, this equipment can be used to install the equipment introduced in this invention from the condenser outlet to the low pressure turbine heat exchanger. It becomes possible to set the temperature to a higher temperature than before, which has the great effect of improving the thermal efficiency of the entire plant.

Additionally, compared to conventional condensate purification equipment that combines filters and mixed bed desalination equipment for the purpose of maintaining higher water quality in nuclear power plants, the present invention achieves the objective with a single type of equipment. In order to be
It is expected to reduce the installation space and improve economic efficiency.

〔Effect of the invention〕

According to the present invention, crud contained in condensate,
It has the effect of being able to remove impurities with different properties, such as ions, and minimizing the amount of waste generated during regeneration and backwashing operations performed to continuously use equipment.

[Brief explanation of the drawing]

Figure 1 is a system diagram showing the position of the condensate purification equipment of the present invention in the overall system of a standard BWR type nuclear power plant, and Figure 2 shows the system configuration of the condensate purification equipment. be. In Figure 1, 1... nuclear reactor, 4... condenser, 7... condensate purification equipment. In Fig. 2, 1... acid tank for regeneration, 2... caustic tank for regeneration, 3... ion clad filter.

Claims (1)

[Claims] 1. As a condensate purification filter for purifying condensate, an ion exchange group is bonded to a porous fibrous or membrane-like thermally decomposable material that has crud removal performance to provide ion exchange ability. A condensate purification equipment characterized by using a filter.