JPS59183885A - System for regenerating ion exchange resin - Google Patents

Abstract

PURPOSE:To reduce the amount of a waste liquid following the backwashing regeneration of an ion exchange resin and to simplify the treatment of the waste liquid, by performing the backwashing regeneration of the used ion exchange resin by providing a backwashing water recirculating and purifying apparatus to a blended bed type condensed water desalting apparatus. CONSTITUTION:When a corrosive product is sufficiently collected by the resin in a condensed water desalting tower 5, the resin is transferred to a cation exchange resin regenerating tower 8 to be subjected to backwashing regeneration. The corrosive product released from the resin by the scrubbing of water and air in this tower 8 is discharged by washing water and collected in a purifying apparatus 16. Washing water after purification is again injected into the cation exchange resin regenerating tower 8 as washing water by a regenerated water transfer pump 17. After backwashing regeneration is finished, the resin is transferred to a resin mixing tower 10 to be mixed but, as transfer water and mixing water at this time, purified water is also used to perform the transfer and mixing of the resin.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for regenerating a condensate desalination device, and particularly a regeneration system suitable for waste liquid treatment during backwash regeneration of resin used for desalination of condensate. Regarding.

[Prior art]

In nuclear reactors, especially boiling water reactors, corrosion products occur due to corrosion of sub-system equipment and piping, and after being activated in the reactor, they adhere to the piping, causing an increase in the plant dose rate. Become. Therefore, it is important to remove as much corrosion products as possible in the condensate purification system and limit the amount brought into the furnace.

FIG. 1 shows an example of the system, fi, and outline of a conventional boiling water reactor. Steam coming out of the reactor pressure vessel 1 passes through a high pressure turbine 2 and a low pressure turbine 3 and becomes condensed water in a condenser 4 2, an extraction system 7 connecting the condenser 4, the turbine 3 and a feed water heater 6, and a feed water heater Corrosion products (iron, cobalt, etc. ions and oxidation) generated in the condensate water demineralization tower 5 are decapitated or removed by the condensate demineralization tower 5. Afterwards, it is destroyed in the reactor pressure vessel 1.

Condensate desalination tower5. Assuming emergencies such as a leak of seawater for cooling in condenser 4, several units of the late R03/tower were installed with a mixed filling of H-jo cation exchange resin and OH-type anion/ion exchange resin. has been done.

By the way, the conventional resin regeneration in the condensate demineralization tower in boiling water type atomic couplers is an external regeneration method in which the resin is removed from the condensate demineralization tower and regenerated separately in order to avoid contamination of the condensate and water supply lines. This is common, and the increase in the amount of waste such as recycled waste liquid accompanying the recycling of these resins has become a problem. Resin regeneration can be divided into two types: removal of oxides mechanically trapped in the resin and removal of oxides chemically trapped by ion exchange reactions. The former is carried out by scrubbing with air and water, and the latter is carried out by chemical injection.

Figure 2 shows the regeneration system of Kitaki's conventional mixed-bed condensate desalination equipment using the outside-column regeneration method. The ion exchange resin, which is backwashed and regenerated by differential pressure or periodic control, is transferred to the cation exchange resin tower 8, and oxides trapped on the resin surface are removed by the injected water and air. The stripped oxides are discharged to the waste treatment system using wash water. The resin is then transferred to the resin mixing tower 1o, where it is mixed and then
The condensate is again packed into the demineralization tower 5. In addition, for regeneration by injection of chemicals, the cation exchange resin and anion exchange resin are separated in the cation exchange resin tower 8, and the anion exchange resin is transferred to the anion exchange resin tower 9, and after regeneration by injecting chemicals,
The resins are mixed in the resin mixing tower 1o and charged into the condensate demineralization tower 5.

Regeneration by backwashing is 20 days/time, regeneration by chemicals is 100 days/time.
It is normally carried out at a frequency of about once a day, and since it has several demineralization towers, backwash regeneration requires 11 o.

The amount of waste liquid in MWe-class plants has reached approximately 12,000 m2 per year.This waste liquid is concentrated in the waste treatment system, but the operation is almost at full capacity, so reducing the amount of waste liquid is a problem. It becomes.

[Purpose of the invention]

An object of the present invention is to provide a method for regenerating a condensate desalination apparatus that reduces the amount of waste liquid associated with resin backwash regeneration and simplifies waste liquid treatment.

[Summary of the invention]

In the backwashing regeneration of ion exchange resin in condensate desalination equipment, the present invention eliminates a large amount of waste liquid by injecting water and air and scrubbing, and then draining and removing corrosion products that have peeled off from the resin using washing water. However, if a purification device is installed in the regeneration tower and the water in the regeneration tower can be circulated, the amount of water injected can be enough to fill the piping of the regeneration tower and the circulation system, and the waste liquid can be Since it is concentrated, its processing can be simplified.

[Embodiments of the invention]

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

Figure 3 shows the purification device 1 in the regeneration system of the condensate desalination device of the present invention.
6 is installed. When corrosion products and the like are sufficiently captured in the resin in the condensate demineralization tower 5, the resin is transferred to the cation exchange resin regeneration tower 8 and backwashed and regenerated. Here, the corrosion products that have been scrubbed with water and air and peeled off from the resin are discharged by the washing water and collected in the purification device 16. The purified washing water is again injected into the cation exchange column 8 as washing water by the recycled water transfer pump 17.

After the backwash regeneration is completed, the resin is transferred to the resin mixing tower 10 and mixed, and the purified water is also used for the transfer water and mixing water at this time. Here, the amount of waste liquid obtained by using an electromagnetic filter in the purification device 16 is shown. The amount of corrosion products removed by backwash regeneration is approximately 10 kg/time, and the amount of iron captured by a small (approximately 30 m'/H1) electromagnetic filter required for backwash regeneration is approximately 2,000 kg. Backwashing Regeneration In one dyeing operation, backwashing of 5 homogeneous electromagnetic filters is required.The amount of backwashing waste liquid in the electromagnetic filter is approximately 20,011 times, so one resin backwashing and regeneration operation requires approximately 1m. Conventional resin backwashing and regeneration operations produced approximately 100 m'' of waste liquid, but the amount of waste liquid can be reduced to approximately 1/100, and the liquid is 100 times more concentrated. Processing in the processing system is simplified.

〔Effect of the invention〕

According to the present invention, it is possible to reduce the waste liquid during backwashing and regeneration of the resin in the condensate desalination equipment, and since the waste liquid becomes concentrated, the effect of reducing the load on the waste treatment system is reduced. be.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of a conventional boiling water nuclear power plant, Figure 2 is a configuration diagram showing the regeneration system of a mixed-bed condensate desalination equipment using a conventional external regeneration method, and Figure 3 is a conventional This is a configuration diagram showing a regeneration system in which a purification device is installed in the condensate demineralization tower regeneration system and backwash waste liquid is circulated and purified. 5... Keishui tax salt tower, 8... Cation exchange resin regeneration tower, 9... Anion exchange resin regeneration tower, 1o... Resin mixing tower, 16... Purification device. Agent Patent Attorney Akio Takahashi 1, ' Iro Taku l Diagram°, □, I, ~, Shi7

Claims (1)

[Scope of Claims] 1. An ion exchange resin regeneration system characterized in that a method for backwashing and regenerating used resin in a mixed bed type condensate desalination apparatus is provided with a device for circulating and purifying backwash water. 2. In claim 1, the purification device is provided with an electromagnetic filter! Characteristic ion exchange resin regeneration system.