JPS5919550A - Reduction of high-electric conductive liquid waste during regeneration of ion-exchange resin and apparatus therefor - Google Patents

Abstract

PURPOSE:To reduce high-electric conductive liquid waste, by reserving it in liquid waste tanks annexed to columns for regenerating both of cation and anion- exchange resins, and using it for the regeneration of said ion-exchange resin. CONSTITUTION:Liquid waste tanks 32, 33 for high-electric conductive liquid waste are annexed to a cation-exchange resin regenerating columns 3 and an anion-exchange resin regenerating column 4. In the regenerators connected to a column 1 for the desalination of condensed water, low-electric conductive liquid waste is reserved in a liquid waste tank 2 directly connected to the desalinator column 1, while high-electric conductive liquid waste is reserved in the liquid waste tanks 32, 33 directly connected to the regenerator columns 3, 4 and used for the regeneration of ion-exchange resins. Thus, an amount of water to be used is saved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for reducing waste liquid, particularly high conductivity waste liquid, during the cleaning and regeneration process of ion exchange resins.

In the condensate desalination method of nuclear power plants, recycled waste liquid is naturally generated during the cleaning and regeneration process of ion exchange resin. For example, the current amount of waste liquid generated (approximately per co-tower) is based on the amount of water used for backwash/rewash (Make-up Water
, hereinafter referred to as MUWC) is approximately 130m8/? The recycled waste liquid generated violet is a low conductivity waste liquid (Low 0oncl).
Utility Waste (hereinafter referred to as LCW)
is approximately 100m”/cycle, high conductivity waste fi (Hi
ghConductivity Wa, ste below HC
W) typically occurs at approximately 40 m8/cycle.

However, the amount generated above indicates the maximum amount during drug regeneration with a backwash frequency of 3 times/cycle.

The purpose of the present invention is to recover and reuse HCW, which is generated along with saving necessary water usage (MUWO). In nuclear power plants, the regeneration of contaminated ion exchange resin usually requires the use of water and air to transfer the resin in the desalination tower to the regenerator, and the transfer of the resin in the regenerator and the external regeneration are necessary. Large amounts of water and air are used in the operation. The air and water used in these resin transfer and regeneration operations are all discharged as commercial air or wastewater, which becomes a burden for the delicate but radioactive waste disposal at nuclear power plants, and the wastewater treatment is a serious matter, and it is necessary to reduce the generation of @ liquid.

It is unprecedented to provide a waste liquid tank as described below for such a purpose.

The present invention will be explained below with reference to the drawings. Figure 1 shows that the waste liquid, especially HCV/, according to the present invention is utilized in the process to produce HCW.
FIG. 2 is a process explanatory diagram of an ion exchange resin regeneration device that reduces waste. 1 is a desalination tower, 30 is a filter,
The recycled resin is transferred through the pipe 6 at the bottom of the resin storage tank 5 and flows into the desalination tower from the top. Air 7 is sent and resin is transferred from piping 9. 8 is srunung water. The waste liquid is sent to the waste liquid pipe 2 through the pipe 10. Some will be discarded. The resins (cation exchange resin and anion exchange resin) transferred through the pipe 9 are sent to the upper part of the cation exchange resin regeneration tower. Here, the air scrubber and backwashing are repeated, and the difference in specific gravity is used to divide the resin into two layers: cation exchange resin and anion exchange resin. It is sent to the upper part of the A resin regeneration tower. Next, in the cation exchange resin regeneration tower, 8% HSo is introduced from 28 as a regenerating agent and used, and the regenerated cation exchange resin enters the upper part of the resin storage tank 5 from below through the pipe 19.

Next, in the anion exchange resin regeneration tower, 4% NaOH is introduced as a regenerating agent through 29 to regenerate the anion exchange resin, and enters the upper part of the resin storage tank 5 through pipe #24.

The cation exchange resin tank 3 and the anion exchange resin tank 4 are each equipped with an extraction tank], 2, 13, 14゜20, '21.2
2 and variance 'ayx5. The overflow is discharged from 12 and 20.

Also, each type has air.

It is equipped with piping for backwashing water, sluicing water, and washing water. In the resin needle 1 and 5, 25 and 26 are extraction tubes, and 27 is a dispersion tube. This storage tank 5 is also provided so that air, backwash water, and sluicing water are introduced from the bottom, and wash water is introduced from the top. In addition, a discharge pipe is provided for each type.

Now, the high conductivity waste liquid stored in the HCW waste liquid tanks 32 and 33 is introduced from the lower part of the cation exchange resin regeneration tower 3 and the lower part of the anion exchange resin regeneration tower 4 through the necks 36 and 39, respectively, to regenerate the resin. used for purposes.

Furthermore, the HOW waste liquid can also be used as water for diluting chemical solutions.

Examples of comparative experiments will be shown below regarding the generation of waste liquid from conventional resins (cation and anion exchange resins) and the generation of waste liquid by the cutting edge of the present invention.

From the above results, the recovery of HCW of the present invention is as follows: (1) During regeneration of cation exchange #resin, recovery of HCW during rapid washing/transfer step is approximately 113.5 rns (2) Anion exchange When regenerating the resin, @,
*Recovery of HCW during cleaning/transfer process: approximately 83 m3 Total HCW recovery: approximately 25.8 m3. Based on the results of the above actual tests, the reduction in HCW was conventionally approximately ao7
713/cycle became approximately 3 om''/cycle, and we were able to obtain good results in that the amount of generation was reduced to the conventional 75%.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the ion exchange resin regenerating apparatus of the present invention, which utilizes waste liquid in the process. 1... Desalination tower, 2... Waste liquid tank, 3...
Cation exchange resin regeneration tower, 4... Anion exchange resin regeneration tower, 5... Resin storage tank, 6... Regeneration tube resin transfer pipe, 9... Pre-regeneration resin transfer pipe, 10.1],,
31.・Waste transfer monitoring, 32.33・Waste liquid tank (HCW)
), 34.35.36... drunkenness, 3'7, 38.3
9...Piping. Representative Patent Attorney 1 Masahiro Kurosaki + Supplementary iE Shoakira, Seiji 1957] February 27th] Display of the case; 1lJ 1957 Patent Application No. 129414 2, Title of Invention High conductivity during ion exchange resin regeneration Rate precipitation reduction method and its device 3 Relationship with the case of the person making the amendment Patent applicant address 11 Haneda Asahi-cho, Ota-ku, Tokyo] Name (
023) Ebara Corporation (and 1 other person) Representative: Seiji Hatakeyama 4, Agent: 101 As shown in the attached sheet (1)

Claims (1)

[Scope of Claims] l A condensate diversion tower connected by piping equipped with appropriate valves;
Low conductivity waste liquid tank, cation exchange resin tower, anion exchange resin regeneration tower, high conductivity waste liquid tank and resin storage tank attached to both regeneration towers, and condensate demineralization tower. In the process of regenerating and cleaning contaminated ion exchange resin using a connected ion exchange resin regeneration device, low conductivity waste liquid is placed in a waste liquid tank directly connected to the previous 3-pi condensate demineralization tower, and is also attached to both resin regeneration towers. 1. A method for reducing high conductivity waste liquid during ion exchange resin regeneration, characterized by storing high conductivity waste liquid in a waste liquid tank, and using the waste liquid for regenerating ion exchange resin. 2. The waste liquid reduction method according to claim 1, characterized in that the high conductivity waste liquid stored in the high conductivity waste liquid tank is used for regenerating both ion exchange resins. 3 Condensate demineralization tower, low conductivity and high conductivity waste liquid tanks,
A device for reducing high conductivity waste liquid during ion exchange resin regeneration, which comprises a cation exchange resin regeneration tower, an anion exchange resin regeneration tower, and a resin storage tank connected by piping equipped with appropriate valves.