JPH09262486A - Regenerating method of ion exchange resin in desalting device for condensate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerating method of an ion exchange resin in a desalting device of condensed water by which elusion of an org. material from the ion exchange resin can be prevented, decrease in the ion exchange performance of the ion exchange resin is prevented, and therefore, the water quality of the desalted water is maintained high purity, and corrosion in a boiler or a steam generator can be prevented, and moreover, the ion exchange resin can be regenerated at a low cost. SOLUTION: In the regenerating method of an ion exchange resin in a desalting device for condensed water, a mixture ion exchange resin 3 comprising a cation exchange resin 3A and an anion exchange resin 3B used in a desalting tower where condensed water containing hydrazine and heavy metal ions is treated is regenerated in a regenerating facility 1. When the mixture ion exchange resin 3 is sent from the desalting tower 2 to the regenerating tower 4 of the regenerating facility 1, deaerated water is used as a carrier water or a deaerated water and nitrogen gas are used as a carrier fluid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating an ion exchange resin used in a condensate demineralizer in a thermal power plant or a pressurized water nuclear power plant, and more particularly, a hydrazine-adsorbed cation exchange resin. Regarding the method.

[0002]

2. Description of the Related Art Conventionally, in a thermal power plant or a pressurized water nuclear power plant, from the viewpoint of preventing corrosion damage of boilers, steam generators, etc., AVT treatment is performed by adding ammonia and hydrazine to condensate. In addition, a purification system is provided because it is necessary to highly purify the condensate from the same viewpoint. As this purification system, a single or a plurality of purification devices such as a condensate demineralizer equipped with a mixed bed desalination tower (hereinafter simply referred to as "desalination tower"), a powder ion exchange resin filter, and a hollow fiber membrane filter are used. A combination is used. Of these, the condensate demineralizer is usually configured to include a plurality of demineralization towers for purifying by passing condensate water, and a regeneration facility for regenerating the mixed ion exchange resin used in each demineralization tower. The mixed bed type demineralization tower is filled with a mixed ion exchange resin in the tower. This mixed ion exchange resin is a homogeneous mixture of H-type or NH ₄ -type strongly acidic cation-exchange resin and OH-type strongly basic anion-exchange resin.
Condensate is treated as follows in the condensate demineralizer.

That is, condensate is passed in parallel through a plurality of demineralization towers, and cations such as ammonia, hydrazine, Na ions, Fe ions, Cu ions, Cl ions, SO ₄ contained in the condensate. Impurity ions such as anions such as ions are removed from the condensate by the ion exchange action, and suspended substances mainly composed of metal oxides such as iron oxide contained in the condensate (generally called “clad”) ) Is removed by filtration or physical adsorption, resulting in
Purified treated water is obtained.

When such water flow is continued, one of a plurality of demineralization towers increases pressure loss due to accumulation of clad or the like, reaches a constant volume throughput, or ion in the demineralization tower. When the exchange resin reaches the so-called water passage end point, such as when it reaches the once-through point, only the desalting tower is disconnected from the water passage system, and water is introduced from the lower part of the desalination tower, while air is supplied from the upper part. To transfer the used mixed ion exchange resin in the demineralization tower to the regeneration tower in the regeneration equipment.

After transferring the mixed ion exchange resin to the regeneration tower, the already regenerated cation exchange resin and anion exchange resin are transferred from the regeneration equipment to the desalting tower using water pressure and air pressure in the same manner as above, After filling the desalting tower with both ion exchange resins, air is blown from the bottom of the desalting tower to mix both ion exchange resins (this is referred to as "desalting tower mixing") to form a uniform mixed ion exchange resin layer. After the formation, the condensate water is again started to flow into the desalination tower.

On the other hand, with respect to the used mixed ion-exchange resin transferred to the regeneration tower, first, while the mixed ion-exchange resin is immersed in water, air is blown into the regeneration tower from its lower portion to stir it with air. (This is referred to as “air scrubbing cleaning”), and thereby an operation of physically peeling the clad such as metal oxide adhering to the surface of the mixed ion exchange resin is carried out. In some cases, this scrubbing cleaning is not performed before the acid regenerant is passed, but after the acid regenerant is passed.

Next, washing water is supplied from the lower part of the regeneration tower (this is called "backwashing"), and the clad such as metal oxide separated by the air scrubbing washing is discharged out of the tower together with the washing water. . Then, backwashing is continued in the regeneration tower to separate the cation exchange resin into the lower side and the anion exchange resin into the upper side by utilizing the difference in specific gravity between the cation exchange resin and the anion exchange resin. After this separation operation, each ion exchange resin is allowed to settle, then an acid regenerant such as hydrochloric acid or sulfuric acid is passed through the cation exchange resin in the lower layer, and an alkali regenerator such as an aqueous sodium hydroxide solution is regenerated in the anion exchange resin in the upper layer. The agent is passed, and the impurity ions captured in the respective ion exchange resin layers are desorbed by the respective regenerants to regenerate the ion exchange resins in the upper and lower layers. Incidentally, as a regeneration method, both ion exchange resins are separated and a cation exchange resin layer is provided on the lower side,
An anion exchange resin layer is formed on the upper side, and the cation exchange resin in the lower layer is allowed to pass an acid regenerant, and the anion exchange resin in the upper layer is allowed to pass an alkali regenerant in a single-column regeneration system. There is a separation and regeneration system in which after separating the ion exchange resin, the upper layer anion exchange resin is transferred to another regeneration tower and both ion exchange resins are regenerated in separate towers.

The condensate demineralizer used for purification of condensate shifts the water passage times of a plurality of desalting towers from each other, and adjusts the desalting towers so as to reach the water passage end point at almost regular intervals. The used mixed ion-exchange resin in each desalting tower is sequentially regenerated in the regenerating tower at approximately equal intervals of water passage. Therefore, the two ion-exchange resins that have completed the regeneration operation in the regeneration tower are allowed to stand by in the regeneration tower as they are until the next desalting tower reaches the water passage end point.

By the way, the quality of the treated water required for the condensate demineralizer has become more and more highly purified in recent years from the viewpoint of preventing corrosion damage and scale damage in boilers, steam generators, etc., such as Na ion and Cl ion. For each is 0.0
The concentration tends to be 1 μg / L (0.01 ppb) or less. Therefore, various improvements have been made to the condensate demineralizer in order to obtain high-purity treated water, and as a result, at present, the target purity can be sufficiently achieved.

[0010]

However, in the case of the conventional condensate demineralizer, the inorganic ions such as Na ions and Cl ions and the clads such as metal oxides are removed, and the water quality target of the treated water is sufficiently achieved. However, if the used mixed ion-exchange resin is transferred from the desalting tower to the regeneration tower for regeneration and the regenerated ion-exchange resin is transferred to the desalting tower and reused, the There was a problem that organic matter leaked out though it was a trace amount, and there was a problem that the ion exchange performance of the anion exchange resin of the mixed ion exchange resins deteriorates in flowing water and Cl ions and SO ₄ ions cannot be sufficiently removed. .

By the way, according to the recent research on leakage of organic matter, the organic matter contains oligomers of styrene sulfonic acid, low molecular weight polymers, and high molecular weight polymers. It is known that the copolymer of styrene and divinylbenzene used is eluted from the strongly acidic cation exchange resin which is sulfonated. In particular, such a high molecular polymer is often eluted from an old cation exchange resin, and hardly eluted from a new cation exchange resin. Also,
If a new cation-exchange resin together with Fe ions, Cu ions or their oxides is immersed in pure water containing dissolved oxygen for a long period of time, or if air, which is an oxygen-containing gas, is blown into the cation-exchange resin, the cation-exchange resin will get high. Molecular polymer is generated. From this, it is considered that the high molecular polymer was generated by the breakage of the high molecular chain due to the oxidation of the cation exchange resin.

From the above facts, in order to prevent the high molecular polymer from being eluted from the cation exchange resin, it is sufficient to prevent the cation exchange resin from being oxidized. A method for preventing the oxidation is to use nitrogen gas in the regeneration equipment. Scrubbing with, or chemical regeneration with an acid regenerant before scrubbing to produce Fe ions or Cu in advance.
Methods such as removing ions have been considered.

However, the amount of water and the amount of gas used in the regeneration step are about 400 m ^{3 of} pure water and about 800 g of gas in a standard condensate demineralizer using 12 m ³ of ion exchange resin.
Nm ³ is required, and particularly when nitrogen gas is used as the gas, the amount of nitrogen gas used reaches about 1 ton in terms of liquid nitrogen. However, when the condensate demineralizer is operated in H-OH, it is necessary to regenerate the ion exchange resin once every 2 to 3 days. Therefore, in the regeneration method using nitrogen gas, In reality, such a recycling method has not been adopted because the usage amount becomes too large and the recycling cost becomes high. Moreover, in order to completely prevent the oxidation, it is necessary to use pure water and an inert gas in which the dissolved oxygen is reduced in all the steps during regeneration, and there is a problem that the regeneration cost becomes higher.

Moreover, when organic substances such as high molecular weight polymers are eluted from the ion exchange resin and are contained in the treated water, these organic substances are decomposed under high temperature and high pressure inside the boiler, steam generator, etc., and SO There is a problem that ₄ ions and the like are generated, and SO ₄ ions and the like have an adverse effect such as promoting corrosion of these devices.

A high-molecular polymer (molecular weight of 100,000 or more) eluted from the regenerated cation exchange resin.
Is adsorbed on the anion exchange resin while condensate is being passed through the desalting tower, which is extremely difficult to desorb from the anion exchange resin, and if the adsorption amount becomes too large, the ion exchange capacity of the anion exchange resin will increase. It has been confirmed that the amount of water decreases, and if it is left as it is, Cl ions and SO ₄ ions leak, which poses a new problem that the above-mentioned severe water quality requirements cannot be satisfied.

The present invention has been made to solve the above-mentioned problems, and prevents the elution of organic substances from the ion exchange resin and prevents the deterioration of the ion exchange performance of the anion exchange resin. A method of regenerating the ion exchange resin in the condensate desalination equipment that can maintain the water quality at a high level of purity and prevent corrosion of the boiler, steam generator, etc., and also regenerate the ion exchange resin at low cost. It is intended to be provided.

[0017]

As a result of various investigations and tests on the oxidation mechanism of ion exchange resins, particularly cation exchange resins, the present inventors have found the following. That is, for example, in the case of a condensate demineralizer for a pressurized water nuclear power plant that uses a copper alloy for the condensate pipe, the wastewater generated when the ion exchange resin is transferred from the demineralization tower to the regeneration tower is collected and drained. Hydrogen peroxide in the wastewater was measured by the phenol-fetalin method and hydrazine in the wastewater was measured by the P-dimethylaminobenzaldehyde method.
Hydrogen peroxide of μg / L or more was detected, and hydrazine was barely detected. The cation exchange resin at this time was sampled, and the amount of hydrazine adsorbed on the cation exchange resin and the amount of metallic copper were measured.
0.5 g / L-resin and metallic copper were 5.8 mg / L-resin. Also, in the case of a condensate demineralizer at a pressurized water nuclear power plant that uses titanium for the condensate pipe, the same measurement results showed that only 15 to 25 μg / L of hydrazine was detected in the wastewater, and No hydrogen oxide was detected. As a result of measuring the adsorption amounts of hydrazine and metallic copper on the ion exchange resin at this time, hydrazine was 12.5 g / L-resin and metallic copper was 2 mg / L-resin or less.

The present inventors have obtained the following findings from the above measurement results. That is, the cation exchange resin transferred from the desalting tower to the regeneration tower adsorbs a large amount of ammonia and hydrazine in the condensate, and also contains a large amount of heavy metal ions mainly composed of Fe ions and Cu ions and their respective oxides. Since it is adsorbed on, when transferring the ion exchange resin, the adsorbed hydrazine undergoes autooxidative decomposition under the catalytic action of adsorbed heavy metal ions, and further produces hydrogen peroxide by contact with dissolved oxygen in water. Hydrogen peroxide is detected in the waste water.

Therefore, in the conventional regenerating operation, pure water and air in which dissolved oxygen is almost saturated are used, and hydrazine and F are added.
The cation exchange resin on which heavy metal ions such as e-ions and Cu ions are adsorbed is transferred from the desalting tower to the regeneration tower, and air is used in the regeneration tower to perform cleaning such as air scrubbing backwashing, so that regeneration is performed. During operation, the cation exchange resin comes into contact with oxygen-saturated dissolved water (pure water), hydrogen peroxide, which is the oxidation product of hydrazine, is generated, and the hydrogen peroxide accelerates the oxidative decomposition of the cation exchange resin, which in turn causes anion exchange. It is considered that the performance of the resin is also lowered, and as a result, organic substances such as high molecular weight polymers, which are oxidative decomposition products of the ion exchange resin, are eluted. In addition, the oxidative decomposition of the above cation exchange resin is significantly affected by Cu ions among heavy metal ions, and in the case of Cu ions, as described above, 5.8.
It has been found that the cation exchange resin is oxidatively decomposed even with an extremely small adsorption amount such as mg / L-resin.

The present invention has been made on the basis of the above findings. The method for regenerating a cation exchange resin in a condensate demineralizer according to claim 1 is a method for treating condensate containing hydrazine and heavy metal ions. In a method of regenerating a mixed ion exchange resin composed of a cation exchange resin and an anion exchange resin used in a salt tower in a regeneration equipment, at least from the step of transferring the mixed ion exchange resin from the desalting tower to the regeneration equipment. Characteristically, deoxidized water is used as water for each step and an inert gas such as nitrogen gas is used as a gas until just before regeneration by passing an acid regenerant into the cation exchange resin. To do.

The method for regenerating a cation exchange resin in a condensate demineralizer according to claim 2 of the present invention is a cation used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In a method of regenerating a mixed ion exchange resin composed of an exchange resin and an anion exchange resin in a regenerating facility, when the mixed ion exchange resin is transferred from the desalting tower to the regenerating tower of the regenerating equipment, it is removed as a transfer fluid. It is characterized by using oxygen water or deoxygenated water and an inert gas such as nitrogen gas.

The method for regenerating a cation exchange resin in a condensate demineralizer according to claim 3 of the present invention is the cation used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In a method of regenerating a mixed ion exchange resin consisting of an exchange resin and an anion exchange resin in a regeneration facility, when separating the mixed ion exchange resin into a cation exchange resin and an anion exchange resin in a cation exchange resin regeneration tower, separation, It is characterized in that deoxidized water is used as the backwash water.

The method for regenerating a cation exchange resin in a condensate demineralizer according to claim 4 of the present invention is a cation used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In a method of regenerating a mixed ion exchange resin composed of an exchange resin and an anion exchange resin in a regeneration facility, after separating the mixed ion exchange resin into a cation exchange resin and an anion exchange resin in a cation exchange resin regeneration tower, the anion When the exchange resin is transferred from the cation exchange resin regeneration tower to the anion exchange resin regeneration tower, deoxidized water is used as transfer water to be passed through the cation exchange resin regeneration tower.

The method for regenerating a cation exchange resin in a condensate demineralizer according to claim 5 of the present invention is the method according to any one of claims 1 to 4, wherein the heavy metal ion is Is a copper ion and / or an iron ion.

As the deoxygenated water, water treated by a deaerator such as a vacuum deaerator or a membrane deaerator, a dissolved oxygen removing device by blowing nitrogen gas, or a dissolved oxygen removing device using a palladium catalyst. Although a deaerator such as a vacuum deaerator is usually attached to the condensate circulation system of a power plant, deaerated water that is treated water of this vacuum deaerator is used as deoxygenated water. Is good to use.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in FIGS. In each drawing, FIG. 1 is an ion-exchange resin regeneration facility that is preferably used when carrying out the ion-exchange resin regeneration method in the condensate demineralizer of the present invention, and shows an example of a separation regeneration method. Figures 1 and 2 show the first embodiment.
FIG. 3 is a graph showing the elution state of TOC from the cation exchange resin in FIG. 3, and FIG. 3 is a graph showing the generation state of hydrogen peroxide accompanying the oxidative decomposition of hydrazine in the case of using the Fe ion adsorption type exchange resin in Example 2. 4 is a graph showing the generation state of hydrogen peroxide associated with the oxidative decomposition of hydrazine when a Cu ion adsorption type exchange resin was used in Example 2.

First, a facility for regenerating an ion exchange resin, which is preferably used when carrying out the method for regenerating an ion exchange resin in a condensate demineralizer of the present invention, will be described with reference to FIG. The ion exchange resin regeneration equipment (hereinafter, simply referred to as “regeneration equipment”) used in the present invention is, for example, a separation regeneration regeneration equipment attached to a condensate demineralizer in a pressurized water nuclear power plant. This regeneration equipment 1 is shown in FIG.
As shown in, the leftmost desalination tower 2 that constitutes the condensate demineralizer
From the used cation exchange resin 3A after receiving the used ion exchange resin 3 to be regenerated from
And the anion exchange resin 3B and the cation exchange resin 3A for regenerating the cation exchange resin 3A.
“First regeneration tower” 4) and anion exchange resin regeneration tower (hereinafter, referred to as “second regeneration tower”) that regenerates the anion exchange resin 3B after receiving the anion exchange resin 3B from the first regeneration tower 4. ) 5, and the regenerated mixed ion exchange resin to receive the regenerated cation exchange resin 3A and the anion exchange resin 3B from the first and second regeneration towers 4 and 5, and to supply them to the empty desalting tower 2 And a first resin storage tank 6 for temporarily storing the resin. In addition, as will be described later, in the present regeneration facility 1, the cation exchange having a small particle size existing near the separation boundary surface of both ion exchange resins during the previous separation operation of the mixed ion exchange resin in the first regeneration tower 4. A small amount of mixed ion exchange resin 3 consisting of resin and large particle size anion exchange resin is extracted from the first regeneration tower and received, and the mixed ion exchange resin 3 is temporarily stored until the next regeneration operation. A storage tank 7 is attached. The first resin storage tank 6 is formed to have a capacity for storing the ion exchange resin corresponding to the filling capacity of the desalting tower, but the second resin storage tank 7 has a much smaller capacity than this. .

A supporting plate 21 is arranged in the lower portion of the desalting tower 2 so that the mixed ion exchange resin 3 is supported by the supporting plate 21. Further, a gas supply pipe 100 for supplying an inert gas such as nitrogen gas and a water supply pipe 101 for supplying water such as condensate are connected to the upper portion of the desalting tower 2, and the lower end thereof is, for example, degassed pure water. A water supply pipe 22 for supplying pure water such as the above and a gas supply pipe 23 for supplying gas such as nitrogen gas or air are connected, and a valve (the reference numeral is omitted in FIG. 1. The same applies to the following valves. ) Is appropriately opened to supply degassed pure water as resin transfer water from the pipe 22 into the desalting tower 2, or if necessary, the degassed pure water is supplied and nitrogen gas is supplied to the gas supply pipe. 10
0 to supply the used mixed ion-exchange resin 3 in the desalting tower 2 through the first resin transfer pipe 8 by the water pressure of degassed pure water or the action of this water pressure and the gas pressure of nitrogen gas. It is transferred to the tower 4. Therefore, one end of the first resin transfer pipe 8 is inserted slightly above the support plate 21 in the desalting tower 2, and the other end is inserted into the upper end portion of the first regenerating tower 4, so that the first desalination tower 2 and the first desalting tower 2 are connected. It communicates with the regeneration tower 4.
Incidentally, 24 is a drain pipe.

A support plate 41 is disposed below the first regeneration tower 4, and the mixed ion exchange resin 3 transferred from the desalting tower 2 is supported by the support plate 41. A water supply pipe 42 and a gas supply pipe 43 similar to those in the desalination tower 2 are connected to the lower end of the first regeneration tower 4, and the pipes 42, 43 are introduced into the first regeneration tower 4 with the valves appropriately opened. Degassed pure water, or nitrogen gas or degassed pure water and nitrogen gas are supplied into the regeneration tower 4, and after scrubbing or backwashing the mixed ion exchange resin 2 in the first regeneration tower 4,
The mixed ion exchange resin 3 is separated by utilizing the difference in specific gravity between the cation exchange resin 3A and the anion exchange resin 3B. In this separation operation, the cation exchange resin 3A
The interface between the ion-exchange resin 3B and the anion-exchange resin 3B cannot be separated neatly, and a layer of the mixed ion-exchange resin 3 in which both ion-exchange resins are mixed remains at the interface portion (indicated by diagonal lines in FIG. 1).

After the separation operation is completed, the separated anion exchange resin 3B in the first regeneration tower 4 and the mixed ion exchange resin 3 therebelow are passed through the second and third resin transfer pipes 9 and 10, respectively. The second resin transfer pipe 9 is used to transfer the second resin to the second regeneration tower 5 and the second resin storage tank 7 sequentially.
Is inserted into the first regeneration tower 4 at approximately the middle in the height direction (a position where only the anion exchange resin can be transferred), and the other end is inserted into the upper end of the second regeneration tower 5, 4 and the second regeneration tower 5 are in communication with each other. Further, one end of the third resin transfer pipe 10 is inserted slightly below the insertion end of the second resin transfer pipe 9 in the first regeneration tower 4 (a position where the mixed ion-exchange resin can be reliably transferred), and the other end is inserted. It is inserted into the upper end portion of the second resin storage tank 7 and communicates between the first regeneration tower 4 and the second resin storage tank 7.

A first distributor 44 is arranged above the mixed ion exchange resin 3 in the upper part of the first regeneration tower 4 for regenerating the cation exchange resin 3A, and a pipe 44 for the same is provided.
An acid regenerant such as sulfuric acid or hydrochloric acid supplied from A is supplied into the first regeneration tower 4 via the distributor 44 to regenerate the cation exchange resin 3A. Also, the first
A second distributor 45 is disposed slightly above the distributor 44, and the second distributor 45 has a water supply pipe 46 and a gas supply pipe 4 similar to the lower end.
7 is connected. Then, pure water is supplied into the first regeneration tower 4 through the second distributor 45 with the valve of the pipe 46 appropriately opened to wash the cation exchange resin 3A after passing the regenerant, and then the first The drain pipe 48 at the lower part of the regeneration tower 4 is discharged as cleaning waste water. The second distributor 45 acts as a collector during the above-mentioned backwashing and separating operations, so that the second distributor 45 collects the backwashing water and the separating water and discharges them from the drain pipe 49 above the first regeneration tower 4. There is.

Furthermore, after the cation exchange resin 3A is regenerated, the regenerated cation exchange resin 3A in the first regeneration tower 4 is transferred from the first regeneration tower 4 to the first resin storage tank 6 by the fourth resin transfer pipe 1
Therefore, one end of the fourth resin transfer pipe 11 is inserted slightly above the support plate 41 in the first regeneration tower 4 and the other end is the upper end of the first resin storage tank 6. The first regeneration tower 4 and the first resin storage tank 6 are inserted into each other and communicate with each other.

Further, since the second regeneration tower 5 for regenerating the anion exchange resin 3B is constructed according to the first regeneration tower 4, the reference numeral according to the first regeneration tower 4 is used in FIG. Only the features of the regeneration tower 5 will be described. The first in the second regeneration tower 5
An alkali regenerant such as sodium hydroxide is supplied to the anion exchange resin 3B via the distributor 54,
The anion exchange resin 3B transferred from the regeneration tower 4 is regenerated. Further, pure water is introduced into the second regeneration tower 5 from the water supply pipe 52 and the gas supply pipe 53 below the second regeneration tower 5.
Alternatively, pure water and a gas such as air can be supplied, and the same water supply pipe 56 and gas supply pipe 57 are connected to the upper part of the second regeneration tower. After the anion exchange resin 3B is regenerated, the regenerated anion exchange resin 3B in the second regeneration tower 5 is transferred from the second regeneration tower 5 to the first resin storage tank 6
The operation of transferring the resin through the fifth resin transfer pipe 12 is performed. Therefore, one end of the fifth resin transfer pipe 12 is inserted slightly above the support plate 51, and the other end is connected to the fourth resin transfer pipe 11. The anion exchange resin 3B in the fifth resin transfer pipe 12 joins the regenerated cation exchange resin 3A transferred from the first regeneration tower 4 and is transferred to the first resin storage tank 6.

A first distributor 61 is arranged at the lower end of the first resin storage tank 6, and a water supply pipe 62 and a gas supply pipe 63 are connected to the first distributor 61, and valves of the pipes 62, 63 are provided. Is opened to supply pure water or pure water and air into the first resin storage tank 6. In addition, a second distributor 64 is provided at the upper end of the first resin storage tank 6, and a water supply pipe 65 is connected to the second distributor 64, and a valve of this pipe 65 is opened to supply pure water to the first resin. It is designed to be supplied into the storage tank 6. The first resin storage tank 6 is connected to the upper end of the desalting tower 2 via the sixth resin transfer pipe 13, and the water supply pipe 6
2. Pure water supplied from the gas supply pipe 63, or the action of pure water and air pressure causes the regenerated mixed ion exchange resin 3 in the first resin storage tank 6 to be transferred to the desalting tower 2. . Incidentally, 66 and 67 are drain pipes.

Since the second resin storage tank 7 is constructed according to the first resin storage tank 6, the reference numeral according to the first resin storage tank 6 is given in FIG. 1 and its explanation is omitted. In the case of the second resin storage tank 7, the second resin storage tank 7 is connected to the first resin transfer pipe 8 via the seventh resin transfer pipe 14, and the degassing pure water supplied from the water supply pipe 72 and the gas supply pipe 73 is supplied. Water as transfer water,
Alternatively, if necessary, a small amount of the mixed ion exchange resin 3 previously stored in the second resin storage tank 7 is mixed with the mixed ion exchange resin 3 from the desalting tower 2 by the action of nitrogen gas pressure using degassed pure water as transfer water. It is merged with and transferred to the first regeneration tower 4.

Next, one embodiment of the method for regenerating the ion exchange resin of the present invention using the present regenerating equipment will be described. When condensate is passed through the condensate demineralizer and the mixed ion exchange resin 3 in one desalting tower 2 reaches the end point of water passage, the mixed ion exchange resin 3 is filled with metal oxide such as iron oxide. A large amount of impurity cations such as hydrazine, Na ions, Fe ions, and Cu ions are adsorbed on the cation exchange resin 3A while the main clad is attached, and Cl ions, SO ₄ ions, etc. are adsorbed on the anion exchange resin 3B. A large amount of impurity anions of are adsorbed.

All of the mixed ion exchange resin 3 in the desalination tower 2 which has reached the end point of water transfer is transferred to the first regeneration tower 4 in the regeneration equipment 1 through the first resin transfer pipe 8 and the second resin A small amount of the mixed ion exchange resin 3 stored in the storage tank 7 is transferred to the first regeneration tower 4 via the seventh resin transfer pipe 14.
At this time, in the desalination tower 2, only degassed pure water is supplied from the water supply pipe 22 into the desalination tower 2 alone, or degassed pure water is supplied from the water supply pipe 22 and nitrogen gas is supplied from the gas supply pipe 100. In the second resin storage tank 7, the degassed pure water alone is supplied from the water supply pipe 72 into the second resin storage tank 7 or the water supply pipe 7 is used.
Degassed pure water and nitrogen gas are simultaneously supplied in an upward flow from both 2 and the gas supply pipe 73. When supplying degassed pure water and nitrogen gas into the second resin storage tank 7 at the same time, degassed pure water is supplied from the lower end and nitrogen gas is supplied from the upper end, as in the case of the desalting tower 2. May be.

During the above-mentioned transfer, in the case of degassed pure water alone, the degassed pure water becomes the transfer water of the mixed ion exchange resin 3, and the water pressure thereof becomes the driving force. Further, when degassed pure water and nitrogen gas are supplied at the same time, the degassed pure water is mixed with the ion exchange resin 3.
And the gas pressure of nitrogen gas becomes the driving force. Therefore, when the mixed ion exchange resin 3 is transferred from the desalting tower 2 and the second resin storage tank 7 into the first regeneration tower 4 using the degassed pure water or the degassed pure water and nitrogen gas, the mixed ion exchange resin 3 is used.
Is in non-contact with oxygen, the cation exchange resin 3A prevents hydrogen peroxide from being generated by oxidation of hydrazine using heavy metal ions such as Cu ions as a catalyst during transfer,
As a result, oxidative decomposition of the mixed ion exchange resin 3 can be prevented, and elution of organic substances such as high molecular weight polymers can be prevented.

After the used mixed ion exchange resin 3 is transferred from the desalting tower 2 into the first regeneration tower 4 and the inside of the desalting tower 2 is emptied, the previously regenerated mixing in the first resin storage tank 6 is carried out. The ion exchange resin 3 is transferred to the desalting tower 2 via the sixth resin transfer pipe 13. At this time, pure water is supplied into the first resin storage tank 6 through the water supply pipe 62, or pure water and air are supplied into the first resin storage tank 6 through the water supply pipe 62 and the gas supply pipe 63. 1. The mixed ion exchange resin 3 in the resin storage tank 6 is transferred into the desalting tower 2. In this transfer step, since impurities such as hydrazine and heavy metal ions are not adsorbed on the mixed ion exchange resin 3, particularly the cation exchange resin 3A, even if the cation exchange resin 3A comes into contact with oxygen, the heavy metal ions are used as a catalyst. Since there is no problem of oxidative decomposition of hydrazine, it is not necessary to use degassed pure water or nitrogen gas.

The used mixed ion exchange resin 3 transferred from the desalting tower 2 is filled in the first regeneration tower 4 while being supported by the support plate 41. At this time, the degassed pure water used as the transfer water flows out from the drain pipe 48 by opening the drain pipes 48 and 49, and the drain pipe 49 is used when nitrogen gas is used as the driving force of the transfer water. Drained from. Then, when all the used mixed ion exchange resin 3 is filled in the first regeneration tower 4, the degassed pure water from the desalting tower 2 or the supply of the degassed pure water and nitrogen gas is stopped. As a result, the mixed ion exchange resin 3 is placed in a non-contact state with the air, that is, oxygen in the first regeneration tower 4, and even at this stage, the mixed ion exchange resin 3, particularly the cation exchange resin 3A is oxidized and decomposed for the reason described above. Can be prevented.

Then, in the first regeneration tower 4, if necessary,
Degassed pure water is supplied from the water supply pipe 42 in an upward flow to immerse the mixed ion-exchange resin 3 in the degassed pure water, and then nitrogen gas is supplied from the gas supply pipe 43 to perform a scrubbing operation to perform mixing. The clad such as metal oxide adhering to the surface of the ion exchange resin 3 is physically peeled off. After this stripping operation, the supply of nitrogen gas is stopped, degassed pure water is supplied from the water supply pipe 42 in an upward flow to backwash the mixed ion exchange resin 3,
The clad which has been separated is discharged from the drain pipe 49 together with the cleaning water. After the clad is discharged, backwashing is continued with deaerated pure water to separate the mixed ion exchange resin 3 so that the cation exchange resin 3A is separated on the lower side and the anion exchange resin 3B is separated on the upper side. Since degassed pure water and nitrogen gas are used in this series of operations, both ion exchange resins are in a state of non-contact with oxygen, and there is no risk of oxidative decomposition of both ion exchange resins for the reasons described above. .

After the separation operation of the mixed ion exchange resin 3, the first
Degassed pure water is supplied as an upflow from the water supply pipe 42 in the lower part of the regeneration tower 4 into the first regeneration tower 4, or degassed pure water is supplied from the water supply pipe 42 and the gas in the upper part of the first regeneration tower 4 is supplied. When nitrogen gas is simultaneously supplied from the supply pipe 47, the degassed pure water becomes the transfer water, or the degassed pure water becomes the transfer water and the pressure of the nitrogen gas acts as a driving force to remove all of the upper layer anion exchange resin 3B. 2 Transferred to the second regeneration tower 5 via the resin transfer pipe 9. Subsequently, all of the mixed ion exchange resin 3 in the middle layer is transferred to the third resin transfer pipe 10 in accordance with the transfer operation of the anion exchange resin 3B.
To the second resin storage tank 7 via. Also in these transfer operations, the cation exchange resin 3 on the lower side in the first regeneration tower 4
Since degassed pure water is used as the transfer water that passes through A and nitrogen gas is used as the gas, there is no risk of the cation exchange resin 3A being oxidatively decomposed for the reasons described above.

After the upper layer anion exchange resin 3B and the middle layer mixed ion exchange resin 3 have been transferred from the first regeneration tower 4 as described above, the first regeneration tower 4 makes a first passage through the pipe 44A.
After supplying an acid regenerator such as hydrochloric acid and sulfuric acid from the distributor 44 to desorb heavy metal ions such as Na ions, Fe ions and Cu ions from the used cation exchange resin 3A to regenerate it as the H-type cation exchange resin 3A, Pure water is supplied from the first distributor 44 through the pipe 44A to push out the acid regenerant remaining in the packed bed, and then pure water is supplied from the second distributor 45 to wash the cation exchange resin 3A. The regeneration operation of the cation exchange resin 3A is completed. When passing through this acid regenerant,
The hydrazine adsorbed on the cation exchange resin 3A does not undergo auto-oxidative decomposition because the inside of the cation exchange resin layer is in an acidic region due to the passing of the acid regenerant, and there is no risk of oxidative decomposition of the cation exchange resin 3A. The dilution water used for is not necessarily degassed pure water.

In the first regeneration tower 4, when the metal oxide remains on the surface of the cation exchange resin 3A after passing through the acid regenerant, the deposit is peeled off by scrubbing backwash. Since hydrazine has already been desorbed from the cation exchange resin 3A and the heavy metal ion serving as a catalyst has also been desorbed at the same time, the cation exchange resin 3A does not generate hydrogen peroxide. Therefore, it is not necessary to use degassed pure water or nitrogen gas in the scrubbing backwash operation at this point. However, in consideration of general oxidation by oxygen, it is preferable to use deaerated pure water or deaerated pure water and nitrogen gas for all operations.

In parallel with the above-mentioned regeneration operation of the cation exchange resin 3A, the second regeneration tower 5 is hydroxylated into the second regeneration tower 5 through the first distributor 54 by the same operation as in the first regeneration tower 4. After supplying an alkali regenerant such as sodium aqueous solution to desorb Cl ions and SO ₄ ions adsorbed on the used anion exchange resin 3B to regenerate it as an OH type anion exchange resin 3B, it is subjected to an extrusion step and a washing step. The regeneration operation of the anion exchange resin 3B is completed. In this alkali regeneration operation, since hydrazine and heavy metal ions do not exist, it is not necessary to consider generation of hydrogen peroxide due to hydrazine. It is possible to carry out the regeneration operation with the use of air and air, and it is not necessary to use deaerated pure water or nitrogen gas.

Then, the regenerated cation exchange resin 3A is used.
And the anion exchange resin 3B from the first and second regeneration towers 4 and 5 to the first resin storage tank 6 as the fourth and fifth resin transfer pipes 11 and 12.
Transfer through. In this transfer, since hydrazine and heavy metal ions have already been removed as described above, it is not necessary to use degassed pure water or nitrogen gas for transferring the resin. Both ion exchange resins 3A and 3B can be transferred using pure water and air.

In the case of the one-column regeneration system, the operation from the step of transferring the used mixed ion exchange resin from the desalting tower to the regeneration tower to the separation of the cation exchange resin and the anion exchange resin in the regeneration tower. Is basically the same as in the case of the above-mentioned separation and regeneration system, and therefore it may be carried out in accordance with the above-mentioned separation and regeneration system by using degassed pure water or using degassed pure water and nitrogen gas. In the case of the single-column regeneration system, the mixed ion exchange resin is separated to form a cation exchange resin layer on the lower side and an anion exchange resin layer on the upper side, and then acid regeneration is performed on the cation exchange resin in the lower layer. The agent is supplied in an upward flow to regenerate the cation exchange resin, and at the same time, the alkali regenerator is supplied to the upper layer anion exchange resin to regenerate the anion exchange resin, and the regenerated waste liquid is near the separation boundary surface of both ion exchange resins. Discharge through installed collector. Other operations such as resin transfer are performed according to the separation and regeneration method.

As described above, according to the present embodiment,
When regenerating the mixed ion exchange resin 3 used by the desalination treatment of condensate containing hydrazine and heavy metal ions, the used mixed ion exchange resin 3 is regenerated from the desalination tower 2 into a regeneration facility 1
Since the degassing pure water and / or the nitrogen gas is used at least from the stage of transferring to the cation exchange resin 3A and immediately before the regeneration by passing the acid regenerant into the cation exchange resin 3A, a minimum amount of degassing pure water is required. Compared with the case of using degassed pure water or nitrogen gas in all regeneration processes, it is possible to reduce the amount of degassed pure water or nitrogen gas used, and at low cost. A regeneration operation can be performed. During the above period, deaerated pure water, or deaerated pure water and nitrogen gas are used, so that the used cation exchange resin 3
There is no risk that the hydrazine adsorbed on A will be oxidized by the catalytic action of heavy metal ions such as Fe ions and Cu ions adsorbed on this resin, and therefore there is no risk of producing hydrogen peroxide, and thus the mixed ion exchange resin 3 In particular, it is possible to prevent the cation exchange resin 3A from being oxidized, and it is possible to reliably prevent the elution of organic substances such as high-molecular polymers from the cation exchange resin 3A.

Further, according to the present embodiment, degassed pure water and nitrogen gas are used only at the key points of the resin transfer from the desalting tower 2 to the regeneration equipment 1 and the regeneration step, so that the entire regeneration step is performed. It is possible to regenerate the mixed ion exchange resin 3 at a lower cost as compared with the case of using nitrogen gas. Further, according to the present embodiment, in the case of the mixed ion exchange resin 3 that has been regenerated by the above-described regeneration method, since the mixed ion exchange resin 3 does not contain organic substances such as high molecular weight polymers, the desalting treatment is performed. The eluted organic matter is not brought into the steam generator or the like, and thus SO ₄ ions due to the organic matter in the steam generator or the like can be prevented from being generated, so that the corrosion of the steam generator or the like can be prevented. Furthermore, the ion exchange performance of the anion exchange resin 3B is not impeded by the elution of organic substances from the cation exchange resin during the desalting treatment, and the leakage of Cl ions, SO ₄ ions, etc. is prevented, and the desalting treatment is performed. The water quality of water can be maintained at high purity.

[0050]

EXAMPLES In this example, hydrazine and / or Cu
We investigated the relationship between oxygen, which is an organic substance produced from cation exchange resins that adsorbed ions, and hydrogen peroxide.

Experimental Example 1 Amberlite (registered trademark: manufactured by Rohm & Haas Co.) 200 CP, which is a strongly acidic cation exchange resin obtained by sulfonation of a copolymer of styrene and divinylbenzene, was packed in a column, and 98 was packed in this column. % Hydrazine (commercial product) dissolved in a 2.5% aqueous hydrazine solution, and a cation exchange resin (hereinafter referred to as "hydrazine adsorption type exchange resin") that adsorbs hydrazine at a ratio of about 50 to 80 g / LR. Was prepared).

On the other hand, a hydrazine adsorption type exchange resin is packed in another column, and an aqueous solution containing each reagent of ferrous sulfate and copper sulfate (commercially available) is passed through this column to adsorb hydrazine. Together with Fe ions about 600 mg / L-
A cation exchange resin (hereinafter, referred to as "heavy metal ion-hydrazine adsorption type exchange resin") in which R and Cu ions were adsorbed at a ratio of about 300 mg / LR was prepared.

Two containers of tetrafluoroethylene resin containing 300 mL of degassed pure water were prepared, and 100 mL of the hydrazine adsorption type exchange resin was placed in each container,
These containers were placed in a constant temperature shaker at 50 ° C., and while the hydrazine adsorption type exchange resin in each container was constantly stirred by the constant temperature shaker, air in one of the water was 10 mL / min. Bubbling was continued at the flow rate (Experiment 1). Further, nitrogen gas was continuously blown into the water in the other container at a flow rate of 10 mL / min (Experiment 2).
Then, in each experiment, water in each container was sampled at regular intervals, the TOC concentration (mgC / L) was measured, and the elution state of organic substances from the hydrazine-adsorption type exchange resin was observed.

Experiments 3 to 6 similar to Experiments 1 and 2 were also carried out on a heavy metal ion-hydrazine adsorbing type exchange resin and an untreated cation exchange resin which did not adsorb hydrazine and heavy metal ions. The experimental conditions of Experiments 1 to 6 are summarized below, and the measurement results of each experiment are shown in FIG. FIG. 2 shows the relationship between the elapsed time of stirring and the TOC (total organic carbon) concentration. In FIG. 2, Experiment 1 is marked with ●, Experiment 2 is marked with ○, Experiment 3 is marked with ▲, and Experiment 4 is marked with △.
Experiment 5 is indicated by a square mark, and Experiment 6 is indicated by a square mark.

[Experimental Conditions] Experiment 1: Air was blown into the hydrazine adsorption type exchange resin (●) Experiment 2: Nitrogen gas was blown into the hydrazine adsorption type exchange resin (○) Experiment 3: Heavy metal ion-hydrazine adsorption type exchange Air was blown into the resin (▲) Experiment 4: Nitrogen gas was blown into the heavy metal ion-hydrazine adsorption type exchange resin (△) Experiment 5: Air was blown into the untreated cation exchange resin (■) Experiment 6: No Nitrogen gas was blown into the treated cation exchange resin (□)

In each of the above experimental results, Experiment 2 and Experiment 4
And Experiment 6 corresponds to the case where the cation exchange resin is contacted with pure water substantially free of dissolved oxygen. Then, in these cases, since the TOC concentrations of hydrazine or hydrazine and cation exchange resin adsorbed with heavy metal ions and untreated cation exchange resin are approximately the same level, the cation exchange resin derived from hydrazine or heavy metal ions It can be seen that oxidative decomposition of does not occur. Therefore, the TO detected in Experiment 2, Experiment 4 and Experiment 6
C is due to leakage of organic substances originally present in the cation exchange resin, and although there are some differences in each,
These may be regarded as so-called blank values.

On the other hand, in the case of Experiment 1 in which air was blown into the hydrazine adsorption type exchange resin (this corresponds to the case where the cation exchange resin was contacted with pure water saturated with dissolved oxygen), the above blank value was obtained. Compared with the above blank value, the TOC concentration is slightly higher than that of the blank value.
In the case of Experiment 3 in which air was blown into the heavy metal ion-hydrazine adsorption type exchange resin, it was much higher than the blank value,
Further, the TOC concentration is significantly higher than that of the hydrazine adsorption type exchange resin of Experiment 1. From this result, even if air is blown into the cation exchange resin adsorbing only hydrazine, the cation exchange resin is not so much oxidatively decomposed, but when heavy metal ions are added to this, the oxidative decomposition is greatly accelerated, and the organic matter is decomposed into water as a decomposition product. It is considered to have eluted.

From the above results, it is understood that the factor that promotes the oxidation reaction of the cation exchange resin is a synergistic action of hydrazine adsorbed on the cation exchange resin and heavy metal ions such as Fe ions and Cu ions. It was

Experimental Example 2 A strong acid cation exchange resin Amberlite 200 CP was packed in a column, and an aqueous solution containing a ferric sulfate reagent (commercially available) was passed through the column to pass an Fe ion of about 600 m.
A heavy metal ion adsorption type exchange resin prepared by adsorption at a ratio of g / LR was prepared.

100 mL containing 30 mL of pure water
2 containers made of ethylene tetrafluoride resin are prepared, and nitrogen gas is blown into the water in one container to remove most of the dissolved oxygen in the pure water, while air is blown into the water in the other container to dissolve the dissolved oxygen. Was saturated. 8 g of the heavy metal ion-exchange resin prepared as described above was added to both of these containers, and 0.5 mL of an aqueous solution prepared by diluting hydrazine to 0.1% was further added thereto, and the both containers were stirred at regular intervals. The hydrogen peroxide concentration of the water in the chamber is determined by the hydrogen peroxide concentration test paper (Hishie Chemical Co., Ltd.).
Was used for the measurement. FIG. 3 shows the measurement results.
Also, apart from this, the same amber light 200C as above
An aqueous solution containing a copper sulfate reagent (commercially available product) was passed through a column filled with P to pass Cu ions at about 150 mg / L-
A copper ion adsorption type exchange resin adsorbed at a ratio of R was prepared, the same experiment as above was conducted using the resin, and the hydrogen peroxide concentration in the container was measured at regular intervals. The result is shown in FIG. 3 and 4 show the relationship between the elapsed time of stirring and the hydrogen peroxide concentration (mg / L) in the container. In each figure, Δ and ○ marks are pure water saturated with dissolved oxygen. In the case of, the mark ● indicates the case of pure water in which most of dissolved oxygen was removed.

From the experimental results shown in FIGS. 3 and 4, hydrazine undergoes autooxidative decomposition due to the catalytic action of the heavy metal ions in the heavy metal ion adsorbing type exchange resin to cause peroxidation immediately after the start of stirring in pure water containing saturated dissolved oxygen. It was found that hydrazine did not cause oxidative decomposition and generated hydrogen peroxide in pure water in which hydrogen was generated but dissolved oxygen was almost removed.

Further, although the Cu ion has a smaller adsorption amount than the Fe ion, hydrogen peroxide is generated at almost the same concentration as in the case of the Fe ion. It can be seen that Cu ions have a greater effect on the oxidative deterioration of the exchange resin than Fe ions.

As a result of comprehensively examining the experimental results by combining the above Experimental Examples 1 and 2, the following was found. That is,
In Experimental Example 1, it was found that the cation exchange resin adsorbing hydrazine and heavy metal ions such as Fe ions and Cu ions has more organic eluate due to oxidative deterioration than the cation exchange resin adsorbing only hydrazine. In addition, Experimental Example 2
Showed that hydrazine undergoes auto-oxidative decomposition in the presence of oxygen and heavy metal ions to generate hydrogen peroxide. Therefore, it is considered that hydrogen peroxide accelerates the oxidative deterioration of the cation exchange resin.

The cation exchange resin thus adsorbing hydrazine and heavy metal ions generates hydrogen peroxide by contacting with dissolved oxygen, and accelerates oxidative deterioration of the cation exchange resin. When the resin is transferred from the desalting tower to the regeneration tower using pure water whose dissolved oxygen concentration is almost saturated, hydrazine is autooxidatively decomposed by the catalytic action of heavy metal ions, and further hydrogen peroxide is generated by dissolved oxygen. This hydrogen peroxide causes oxidative deterioration of the ion exchange resin. Further, even if nitrogen gas is used to transfer the ion exchange resin, oxidative deterioration of the cation exchange resin cannot be prevented as long as dissolved oxygen exists during the transfer, and it is basically necessary to transfer it without contacting with oxygen. is there. When regenerating a cation exchange resin that has adsorbed hydrazine and heavy metal ions, nitrogen gas and degassed pure water may be used as carriers when carrying out resin transfer from the desalting tower to the regenerating tower, as in the present invention. It was found that it is necessary to use degassed pure water until the backwash separation operation, which is performed before the acid regenerant is passed through the cation exchange resin in the regeneration tower.

In the above embodiment, degassed pure water and nitrogen gas are used in the important part of the regeneration process, but other chemically inert inert gas can be used instead of nitrogen gas. The degassed water may be degassed by any method, and the water used may not be pure water as long as it is clear to the extent that it does not contaminate the ion exchange resin.

[0066]

As described above, according to the invention described in claim 1 of the present invention, the elution of the organic matter from the ion exchange resin, particularly the cation exchange resin, is carried out in any of the separation regeneration system and the single tower regeneration system. And the deterioration of the ion exchange performance of the anion exchange resin, which in turn can maintain the water quality of the desalinated water at a high purity to prevent corrosion of the boiler, steam generator, etc. It is possible to provide a method for regenerating an ion exchange resin in a condensate desalination apparatus, which can regenerate water at low cost.

According to the second aspect of the present invention, the mixed ion exchange resin is transferred from the demineralization tower to the regeneration tower of the regeneration equipment in both the separation regeneration system and the single-column regeneration system. At this time, prevent deterioration of the cation exchange resin,
It is possible to prevent the elution of organic substances from the cation exchange resin and also prevent the deterioration of the ion exchange performance of the anion exchange resin, which in turn maintains the water quality of the desalted water to a high purity, and the boiler and steam generator. It is possible to provide a method for regenerating an ion-exchange resin in a condensate demineralizer that can prevent corrosion of the like.

According to the third aspect of the present invention, the mixed ion exchange resin is mixed with the cation exchange resin and the anion in the cation exchange resin regeneration tower in both the separation regeneration system and the single column regeneration system. When separating into an exchange resin, it is possible to prevent deterioration of the cation exchange resin, prevent elution of organic substances from the cation exchange resin, and prevent deterioration of the ion exchange performance of the anion exchange resin. It is possible to provide a method for regenerating an ion exchange resin in a condensate desalination apparatus, which can maintain the quality of salt-treated water at a high purity and prevent corrosion of a boiler, a steam generator, and the like.

According to the invention of claim 4 of the present invention, in the separation regeneration system, the mixed ion exchange resin is separated into the cation exchange resin and the anion exchange resin in the cation exchange resin regeneration tower, and then the anion exchange resin is separated. When transferring the resin from the cation exchange resin regeneration tower to the anion exchange resin regeneration tower, it is possible to prevent deterioration of the cation exchange resin and prevent elution of organic substances from the cation exchange resin, and the ion exchange performance of the anion exchange resin. Of the ion-exchange resin in the condensate desalination device, which can prevent the deterioration of boiler, steam generator, etc. Can be provided.

Further, according to the invention of claim 5 of the present invention, in the invention of any one of claims 1 to 4, the heavy metal ion is a copper ion and / or an iron ion. To prevent the generation of hydrogen peroxide due to the oxidation of hydrazine using copper ions and / or iron ions as a catalyst, and thus to prevent the oxidative decomposition of ion exchange resins and the elution of organic substances such as high molecular weight polymers. It is possible to provide a method for regenerating an ion exchange resin in a condensate demineralizer capable of performing the above.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a separation regeneration system in an ion exchange resin regeneration facility that is preferably used when carrying out a method for regenerating an ion exchange resin in a condensate demineralizer of the present invention.

FIG. 2 TO from cation exchange resin in Experimental Example 1
It is the graph which showed the elution situation of C.

FIG. 3 is a graph showing the generation state of hydrogen peroxide due to oxidative decomposition of hydrazine when using an Fe ion adsorption type exchange resin in Experimental Example 2.

FIG. 4 is a graph showing a generation state of hydrogen peroxide accompanying oxidative decomposition of hydrazine when a Cu ion adsorption type exchange resin is used in Experimental Example 2.

[Explanation of symbols]

 1 Regeneration Equipment 2 Desalting Tower 3 Mixed Ion Exchange Resin 3A Cation Exchange Resin 3B Anion Exchange Resin 4 First Regeneration Tower (Cation Exchange Resin Regeneration Tower) 5 Second Regeneration Tower (Anion Exchange Resin Regeneration Tower) 6 First Resin Storage Tank 7 2nd resin storage tank 8 1st resin transfer piping 9 2nd resin transfer piping 10 3rd resin transfer piping 11 4th resin transfer piping 12 5th resin transfer piping 13 6th resin transfer piping 14 7th resin transfer piping

Claims (5)

[Claims] 1. A method for regenerating a mixed ion exchange resin composed of a cation exchange resin and an anion exchange resin used in a desalting tower for treating condensate containing hydrazine and heavy metal ions in a regeneration facility, wherein the mixing is performed. From the step of transferring the ion exchange resin from the desalting tower to the regeneration equipment until at least just before regeneration by passing an acid regenerant into the cation exchange resin, deoxidized water is used as water for each step, Further, a method for regenerating an ion exchange resin in a condensate demineralizer, characterized in that an inert gas such as nitrogen gas is used as a gas. 2. A method for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin used in a desalting tower for treating condensate containing hydrazine and heavy metal ions in a regeneration facility, wherein the mixing is performed. When transferring the ion-exchange resin from the desalting tower to the regeneration tower of the regeneration equipment, deoxidized water or deoxidized water and an inert gas such as nitrogen gas are used as the transfer fluid. A method for regenerating an ion exchange resin in a water desalination apparatus. 3. A method for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin used in a desalting tower for treating condensate containing hydrazine and heavy metal ions in a regeneration facility, wherein the mixing is performed. Ion exchange in a condensate demineralizer characterized by using deoxygenated water as separation and backwash water when separating an ion exchange resin into a cation exchange resin and an anion exchange resin in a cation exchange resin regeneration tower Resin regeneration method. 4. A method for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin used in a desalting tower for treating condensate containing hydrazine and heavy metal ions in a regeneration facility, wherein the mixing is performed. After the ion exchange resin is separated into the cation exchange resin and the anion exchange resin in the cation exchange resin regeneration tower, the cation exchange is performed when the anion exchange resin is transferred from the cation exchange resin regeneration tower to the anion exchange resin regeneration tower. A method for regenerating an ion exchange resin in a condensate desalination apparatus, characterized in that deoxygenated water is used as transfer water to be passed through the resin regeneration tower. 5. The heavy metal ion is a copper ion and / or an iron ion, as claimed in any one of claims 1 to 4.
5. The method for regenerating an ion exchange resin in the condensate desalination apparatus according to any one of 1.