JPS5919551A - Retrenchment of regenerating agent during regeneration of ion-exchange resin, reduction of total solid part and apparatus therefor - Google Patents

Abstract

PURPOSE:To perform the retrenchment of a regenerating agent and the reduction of a total solid part in the step of washing ion-exchange resin for its regeneration, by providing a recovering tank at each of regenerator columns, and repeatedly using the regenerating agent. CONSTITUTION:Sulfuric acid used in a column 3 for the regeneration of cation- exchange resin is sent through a drain pipe 35 to recover the concentration of about 5% only from it by a sensor, adjusted to about 8% by conc. sulfuric acid and then charged through piping 42 in a pipe 28 for reuse in the following acid treatment. Caustic soda is recovered, adjusted and then reused by the same way. Thus, the retrenchment of the regenerating agents is performed, and the formation of a solid part in liquid waste is inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for reducing the amount of regenerants (sulfuric acid, caustic soda) and total solids during the washing and regenerating 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 tower) is
, hereinafter referred to as MUWC), approximately 30i cycles,
The regenerated waste liquid generation discharge is a low conductivity waste liquid (Low Conductivity waste liquid).
tivity WaSte (hereinafter referred to as r, cw) 75 balls approximately 100m9/cycle, high conductivity waste liquid (Hi
gh Conductivity Waste HC
(referred to as W) is typically generated at a rate of about 40 ml/cycle.

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

In nuclear power plants, regeneration of contaminated ion exchange uniforms usually requires the use of water and air to transfer the resin in the desalination tower to the regenerator, and the resin transfer and regeneration operations in the regenerator. Large amounts of water and air are used in this process.

In these resin transfer and regeneration operations, all air and water used is discharged as wash air or waste water;
Although it is a small amount, it becomes a burden on the treatment of radioactive waste in nuclear power plants, and the treatment of this waste liquid is important, and it is necessary to reduce the generation of waste liquid.

In particular, it is discharged into the sulfuric acid and caustic soda waste liquids used as regenerants, and their removal increases the total amount of solids in the waste liquids, which is one of the problems in waste liquid treatment.

In the present invention, in order to reduce the total solid content, a recovery tank is installed in each regeneration tower, and this objective is achieved by repeatedly using the regenerant, which is unprecedented in the prior art.

Since the ion exchange resin used in the condensate desalination equipment has an extremely low ion concentration in the condensate, a portion of the total exchange capacity is used for regeneration. On the other hand, the regenerant is the VOI of the tank.
, LV, time, etc., and unless it can be drastically reduced, an excessive amount will be added to the load. Therefore, it becomes possible to recover and use this excess amount.

The present invention will be explained below with reference to the drawings.

FIG. 1 is an explanatory diagram of the process of the ion exchange sphere fat regeneration device according to the present invention, which reduces the amount of regenerant and prevents the formation of solids.

1 is a desalting tower, and 3o is a filter.

Regenerated 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 to pipe 9
More resin is transferred. 8 is sluicing water.

The waste liquid is sent to the waste liquid tank 2 through the pipe 10.

Some will be discarded. The resin (cations and anions) transferred from the pipe 9 is sent to the upper part of the cation resin regeneration tower 3. Air scraping and backwashing are repeated using N, and the difference in specific gravity is used to separate the resin into two layers: cation exchange resin and anion exchange resin. The resin is sent to the top of the resin regeneration tower. Next, in the cation exchange resin regeneration tower, 8 sulfuric acid is introduced from 28 as a regenerating agent and used, and the cation exchange resin enters the upper part of the resin storage tank 5 from below through the plumber 9.

Next, in the anion exchange resin regeneration tower, and X are introduced and used as a regenerating agent through the four-layer caustic nodal 29, the anion exchange resin is regenerated, and the anion exchange resin enters the upper part of the resin storage tank 5 through the pipe 24. Cation exchange clear oil tank 3. Anion exchange resin tank 4 has A version small tubes 12.13 and ■4.20121, respectively.
．． 22 and dispersion pipes 15, 23, the overflow outlet is discharged from Co-2 and U20. Also, each type has air backwash water.

It is equipped with pipes for pouring through/puffer water and washing water. In the resin storage tank 5, 25 and 26 are small tubes,
27 is a dispersion tube. The storage tank 5 is also equipped with air, backwash water, and cleaning water introduced from the bottom, and cleaning water introduced from the top. Also, each tank will have a discharge pipe.

Sulfuric acid used in the cation exchange resin regeneration tower is recovered to a sulfuric acid recovery tank 40 through a drain pipe 35.

At this time, the used sulfuric acid with a concentration of about 5 parts is recovered using a sensor, and the recovered sulfuric acid with a concentration of about 5 parts is adjusted to 8 parts with concentrated sulfuric acid and added to 28 through 42 for the next acid treatment. used again.

The caustic soda solution used in the anion exchange oil regeneration tower is transferred to the caustic soda recovery tank 4 through piping for 3 days.

will be collected. At this time, a sensor is used to collect the used caustic soda solution with a concentration of about 3 parts as a regenerating agent, and the caustic soda solution with a concentration of about 3 parts collected in the collection tank is reduced to a concentration of 4 parts by adding concentrated caustic soda. It is adjusted and added to 29 through 43 and used again in the next alkali treatment.

Examples of comparative experiments will be shown below regarding the amount of waste liquid generated during regeneration of conventional resins (cation and anion exchange resins) and the amount of waste liquid generated by the method of the present invention.

According to the results of the above, the recovery of the oxalter according to the present invention is (1
) Reaction section in the sulfuric acid cation exchange resin drawing tower, during the extrusion process ・・・・ ・ Approx. 4 m3 (concentration approximately 5%) (2) In the caustic node anion exchange uniform regeneration tower] During the extrusion process・ ・ Approximately 8 m3 (approximately 3 cubic meters of A degree) Through repeated use, the total amount of solid content (mono sulfate, etc.) contained in each recycle is significantly reduced, and the amount of final waste generated is therefore reduced. be done.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the process of the ion-exchange clothing regeneration apparatus of the present invention, which reuses waste liquid and regenerated liquid twice. J... Desalination tower, 2... Waste liquid tank, 3...-
Cation exchange uniform regeneration tower, 4... Anion/exchange resin endogenous tower, 5... Resin storage tank, 6... Pre-regeneration resin transfer pipe, 9...・Resin transfer pipe before recycling,
l 01. '11゜31...--Waste liquid transfer pipe, 32.
33... Waste water tank (HCW), 34, 35.
36・・・・・・・・・Piping, 37°33.39...
... Piping, 40... Sulfuric acid recovery tank, 41...
・・・・・・Caustic noda recovery tank, 42.43・・・・・・
···Piping. Agent Patent Attorney Tadashi Shiozaki Wide Procedure Amendment ν] (Method) January 1980] 31 [] J Indication of the Case Special Revised Application No. 129415 No. 129415 of 1933 Name of the Invention During Regeneration of Ion Exchange Resin If it is a method to reduce cutting of horned beef and reduce the total solid content, the device 3.Relationship with the case of the person who does
023) Ebara Corporation (and 1 other person) 4th generation
Person 〒 1015 Supplementary Order Day Ij

Claims (1)

[Scope of Claims] 1 Consists of a condensate demineralization tower, a waste liquid tank, a cation exchange resin regeneration tower, an anion exchange resin regeneration tower, a resin storage tank, and a regenerant recovery tank connected by piping equipped with appropriate valves. In the process of regenerating and cleaning contaminated ion exchange resin using an ion exchange resin regenerating device connected to a condensate demineralization tower, the sulfuric acid and caustic soda used as regenerants are repeatedly used to reduce the amount of regenerant and produce mirabilite. A method for reducing the amount of regenerant and total solid content during ion exchange resin regeneration, which is characterized by preventing 2. The method for saving regenerant and reducing total solid content as set forth in claim 1, wherein the regenerant recovery tank is a sulfuric acid recovery tank or a caustic soda recovery tank. 3. Regeneration during ion exchange resin regeneration by connecting the condensate demineralization tower, waste liquid tank, cation exchange resin regeneration tower, anion exchange resin regeneration tower, resin storage tank, and regenerant recovery tank with piping equipped with appropriate valves. Equipment for reducing agent consumption and total solid content.