JP2002361245A - Method and device for regenerating ion exchange resin in condensate demineralizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for regenerating an ion exchange resin in a condensate demineralizer by which elution of organic substances from the ion exchange resin is prevented, lowering of ion exchanging performance of an anion exchange resin is prevented, thereby quality of demineralized treated water is maintained at high purity and corrosion of a boiler, a steam generator, or the like, can be prevented and further the ion exchange resin can be generated at a low cost. SOLUTION: Mixed ion exchange resin is composed of a cation exchange resin and an anion exchange resin used in a demineralizing tower for treating condensed water containing hydrazine and heavy metal ions and then is regenerated in a regenerating device. The method and the device for regenerating the ion exchange resin in the condensate demineralizer is characterized by using pure water the temperature of which is always controlled at <=25 deg.C as service water in each process from a stage for transporting the mixed ion exchange resin from the demineralizing tower to a regenerating device at least till just before regeneration performed by making an acid regenerating agent pass through the cation exchange resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for regenerating an ion exchange resin used in a condensate desalination apparatus in a thermal power plant or a pressurized water nuclear power plant. The present invention relates to a method and an apparatus suitable for resin regeneration.

[0002]

2. Description of the Related Art Conventionally, thermal power plants and pressurized water nuclear power plants have been subjected to AVT treatment in which ammonia and hydrazine are added to condensate from the viewpoint of preventing corrosion damage to boilers, steam generators and the like. In addition, since it is necessary to purify the condensed water to a high degree from the same viewpoint, a purification system is provided. As this purification system, purification of a condensate desalination apparatus equipped with a mixed-bed type desalination tower (hereinafter, sometimes simply referred to as “desalination tower”), a powder ion exchange resin filter, a hollow fiber membrane filter, and the like. A single device or a combination of a plurality of devices is employed. Among them, a condensate desalination apparatus is usually composed of a plurality of desalination towers for purifying by passing condensate water, and a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin used in each desalination tower. And a regeneration facility for regenerating the deionized water. The mixed bed type desalination tower is filled with a mixed ion exchange resin in the tower. This mixed ion exchange resin
H type or NH _{4 type} strongly acidic cation exchange resin and OH
In the form of a strongly basic anion exchange resin. In the above condensate desalination apparatus, condensate is treated as follows.

That is, condensate is passed through a plurality of desalination towers in parallel, and cations such as ammonia, hydrazine, Na ion, Fe ion, Cu ion, Cl ion, SO ion, etc. contained in the condensate water. Impurity ions such as ₄ ions and other anions are removed from the condensate by ion exchange,
In addition, suspended substances (generally referred to as “cladding”) mainly containing metal oxides such as iron oxide contained in the condensate are removed by a filtering action or a physical adsorption action, and as a result, purified. Treated water is obtained.

[0004] When such water flow is continued and one of the plurality of desalination towers increases in pressure loss due to accumulation of cladding or the like, when a constant volume treatment amount is reached, or when ions in the desalination tower are reduced. When the exchange resin reaches the flow-through point, for example, when the so-called water-flow end point is reached, only the desalination tower is disconnected from the water system, and water flows in from the lower part of the desalination tower, while air flows from the upper part. To transfer the used mixed ion exchange resin in the desalination tower to the regeneration tower in the regeneration facility.

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 desalination tower using water pressure and air pressure in the same manner as described above. After the deionization tower is filled with both ion-exchange resins, air is blown from the lower part of the desalination tower to mix the two ion-exchange resins (this is referred to as “desalination tower mixing”), and a uniform mixed ion-exchange resin layer is formed. Is formed, and the flow of condensate water into the desalination tower is started again.

On the other hand, with respect to the used mixed ion exchange resin transferred to the regeneration tower, air is first blown into the regeneration tower from a lower portion thereof while the mixed ion exchange resin is immersed in water, and the mixture is stirred by air. (This is referred to as “air scrubbing cleaning.”), Whereby an operation of physically peeling off a clad of metal oxide or the like adhering to the surface of the mixed ion exchange resin is performed. In some cases, the scrubbing cleaning is not performed before the acid regenerant is supplied but is performed after the acid regenerant is supplied.

Next, washing water is supplied from the lower part of the regeneration tower (this is referred to as "backwashing"), and the cladding of metal oxide or the like peeled off by the above air scrubbing cleaning is discharged out of the tower together with the washing water. I do. Thereafter, backwashing is continued in the regeneration tower, and the cation exchange resin is separated to the lower side and the anion exchange resin is separated to the upper side by utilizing the specific gravity difference between the cation exchange resin and the anion exchange resin. After this separation operation, each ion exchange resin is allowed to settle, and then an acid regenerant such as hydrochloric acid or sulfuric acid is passed through the lower cation exchange resin, and an alkali regenerant such as aqueous sodium hydroxide solution is passed through the upper anion exchange resin. The agent is passed, and the impurity ions trapped in each ion exchange resin layer are desorbed by each regenerating agent to regenerate the ion exchange resin in each of the upper and lower layers. As a regeneration method, both ion exchange resins are separated to form a cation exchange resin layer on the lower side and an anion exchange resin layer on the upper side, and an acid regenerant is passed through the lower cation exchange resin as it is. Then, after separating the two ion-exchange resins with a single-column regeneration method in which an alkali regenerant is passed through the upper anion exchange resin,
There is a separation regeneration method in which the upper layer anion exchange resin is transferred to another regeneration tower and both ion exchange resins are regenerated in separate towers.

In the condensate desalination apparatus used for the purification of condensate, the water passage times of the plurality of desalination towers are shifted from each other, and adjusted so that each of the desalination towers reaches the end point of the water passage at substantially regular intervals. In addition, the used mixed ion exchange resin of each desalting tower is sequentially regenerated by the regenerating tower at substantially equal intervals. Therefore, both ion-exchange resins which have completed the regeneration operation in the regeneration tower are kept in the regeneration tower as they are until the next desalination tower reaches the end point of water flow.

In the meantime, the quality of treated water required for a condensate desalination apparatus is becoming more and more strict in recent years from the viewpoint of preventing corrosion damage and scale failure of boilers and steam generators. For example, for Na ion and Cl ion, respectively, 0.01 μg / L (0.01 pp
b) The following concentrations tend to be targeted. For this reason, various improvements have been made to condensate and desalination apparatuses in order to obtain high-purity treated water, and as a result, it is now at a stage where the target purity can be sufficiently achieved.

[0010]

However, in the case of the conventional condensate desalination apparatus, the cladding of inorganic ions such as Na ions and Cl ions and metal oxides is removed, and the water quality target of the treated water is sufficiently reduced. Although it can be achieved, when 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 desalination tower for reuse, the treated water However, there is a problem that organic substances are leaked though the amount is very small, and there is a problem that the ion exchange performance of the anion exchange resin among the mixed ion exchange resins is deteriorated during passing water and Cl ions and SO ₄ ions cannot be sufficiently removed. May have occurred.

According to recent studies on the leakage of organic substances as described above, the organic substances include styrene sulfonic acid oligomers, low molecular weight and high molecular weight polymers, and these organic substances are condensed and desalinated. It has been found that a copolymer of styrene and divinylbenzene, which is commonly used in US Pat. In particular, such high molecular weight polymers
It often elutes from an old cation exchange resin, and hardly elutes from a new cation exchange resin. When a new cation exchange resin is immersed in pure water containing dissolved oxygen for a long time together with Fe ions, Cu ions or their oxides, or air containing oxygen-containing gas is blown into the cation exchange resin, Produces a high molecular polymer. From this, it is considered that the high-molecular polymer was generated by cutting the high-molecular chain by oxidation of the cation exchange resin.

From the above facts, in order to prevent the elution of the high-molecular polymer from the cation exchange resin, it is sufficient to prevent the oxidation of the cation exchange resin. Scrubbing using or, before scrubbing, regenerating chemicals with an acid regenerant
Methods such as removing ions have been considered.

However, the amount of water and the amount of gas used in the regeneration step are, for example, about 400 m ^{3 of} pure water and about 800 Nm ^{3 of} gas in a standard condensate desalination apparatus using 12 m ³ of ion exchange resin. In particular, when nitrogen gas is used as a gas, the usage amount of nitrogen gas reaches about 1 ton in terms of liquid nitrogen. However, the condensate desalination equipment is H-OH
When the operation is performed, it is necessary to regenerate the ion exchange resin once every two to three days. Therefore, in the regeneration method using nitrogen gas, the amount of nitrogen gas used is too large, and the regeneration cost is high. Therefore, such a reproducing method has not actually been adopted. Moreover, in order to completely prevent oxidation, it is necessary to use pure water and an inert gas in which dissolved oxygen is reduced in all steps during regeneration, and there has been a problem that the regeneration cost is further increased.

Further, 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 at high temperature and high pressure inside a boiler, a steam generator, etc. ₄ ions and the like are generated, and there is a problem that SO ₄ ions and the like have an adverse effect such as accelerating the corrosion of these devices.

Further, a high molecular polymer eluted from the regenerated cation exchange resin (100,000 or more in molecular weight)
Is adsorbed on the anion exchange resin while the condensate is passed through the desalination tower, and it is extremely difficult to desorb from the anion exchange resin, and if the amount of adsorption becomes too large, the ion exchange capacity of the anion exchange resin decreases. It is confirmed that the water content decreases, and if left unchecked, Cl ions and SO ₄ ions leak, which causes a new problem that the above-mentioned strict water quality requirements cannot be satisfied.

An object of the present invention is to solve the above-mentioned problems by preventing the elution of organic substances from the ion exchange resin and preventing the ion exchange performance of the anion exchange resin from deteriorating. Water quality can be maintained at high purity to prevent corrosion of boilers, steam generators, etc.
Moreover, it is an object of the present invention to provide a method and an apparatus for regenerating an ion exchange resin in a condensate desalination apparatus, which can regenerate the ion exchange resin at low cost.

[0017]

Means for Solving the Problems In order to solve the above problems, the present inventors first conducted the following investigations and studies. That is, as a result of conducting various investigations and tests on the oxidation mechanism of ion exchange resins, particularly cation exchange resins, the following was found. For example, in the case of a condensate desalination unit of a pressurized water nuclear power plant using a copper alloy for the condenser, the wastewater generated when the ion exchange resin is transferred from the desalination tower to the regeneration tower is collected, and As a result of measuring hydrogen peroxide by the phenol-fetalin method and measuring hydrazine in the wastewater by the P-dimethylaminobenzaldehyde method, 30 μg / L or more of hydrogen peroxide was detected in the wastewater, and only a small amount of hydrazine could be detected. Did not. In addition, the cation exchange resin at this time was sampled, and the amount of hydrazine and the amount of metal copper adsorbed on the cation exchange resin were measured. As a result, hydrazine was 9.8 g / L-resin, and metal copper was 5.2.
mg / L-resin. The same measurement was performed for a condensate desalination unit of a pressurized water nuclear power plant using titanium for the condenser pipe. As a result, 15 to 25 μg /
Only L hydrazine was detected, and no hydrogen peroxide was detected. At this time, the amount of hydrazine and metallic copper adsorbed on the ion exchange resin was measured.
2.3 g / L-resin and metallic copper were 2 mg / L-resin or less.

From the above measurement results, the present inventors first found that:
The following findings were obtained. That is, the cation exchange resin transferred from the desalting tower to the regeneration tower has a large amount of ammonia and hydrazine adsorbed in the condensed water, and a large amount of heavy metal ions mainly composed of Fe ions and Cu ions and their respective oxides. When the ion-exchange resin is transferred, the adsorbed hydrazine is catalyzed by the adsorbed heavy metal ions to cause auto-oxidative decomposition, and further generates hydrogen peroxide upon contact with dissolved oxygen in the water. Hydrogen peroxide is detected in wastewater.

Therefore, in the case of a conventional regeneration operation, hydrazine and F
The cation exchange resin, to which heavy metal ions such as e ions and Cu ions are adsorbed, is transferred from the desalting tower to the regeneration tower, and the air is scrubbed using air in the regeneration tower to perform washing such as backwashing. During the operation, the cation exchange resin comes into contact with oxygen-saturated dissolved water (pure water), and hydrogen peroxide, which is an oxidation product of hydrazine, is generated. The hydrogen peroxide promotes the oxidative decomposition of the cation exchange resin, and thus anion exchange. It is considered that the performance of the resin also deteriorates, and as a result, organic substances such as a high molecular polymer, which is a product of oxidative decomposition of the ion exchange resin, elute. The oxidative decomposition of the cation exchange resin is significantly affected by Cu ions among heavy metals. In the case of Cu ions, 5.2 mg / L is used as described above.
-It has been found that the cation exchange resin is oxidatively decomposed even in an extremely small amount such as resin.

As a result of further investigations and studies, the elution of organic substances such as high molecular weight polymers, which are oxidative decomposition products of the ion exchange resin, is closely related to the temperature of water at that time. By setting the temperature of the
It was found that the elution of organic substances was suppressed to a small level, and the present invention was completed. In other words, the water used for regenerating the ion exchange resin in the condensate desalination apparatus is pure water purified by a makeup water facility or condensate, and the water temperature is 25 ° C to 40 ° C depending on the change in the temperature. It fluctuates seasonally between about ℃. It is known that in the summertime when the temperature is high, the amount of organic matter generated from the desalination apparatus immediately after the regeneration is higher than in the wintertime. From such a point, it was found that there is a possibility that the elution of organic substances can be suppressed to a small level by using water at an optimum temperature, and the present invention has been completed.

The method for regenerating a cation exchange resin in a condensate desalination apparatus according to the present invention is a method for regenerating a cation exchange resin and an anion exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In the method of regenerating the mixed ion exchange resin in the regeneration equipment, from the stage of transferring the mixed ion exchange resin from the desalting tower to the regeneration equipment, until at least immediately before the regeneration by passing the acid regenerant to the cation exchange resin In the meantime, the method is characterized in that pure water whose temperature is constantly controlled to 25 ° C. or lower is always used as water for each step. Hereinafter, the pure water whose temperature is constantly controlled to 25 ° C. or lower may be referred to as “cold pure water” in this specification.

In the present invention, pure water refers to water that has been desalted to an electric conductivity of 1 mS / m (25 ° C.) or less. Desirably, those having a hydrazinium ion concentration of 1 μg / l or less are preferred. The dissolved oxygen may be saturated or reduced by a deaerator.

Further, the method for regenerating a cation exchange resin in a condensate desalination apparatus according to the present invention is a method for regenerating a cation exchange resin and an anion exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In the method of regenerating a mixed ion exchange resin made of a resin in a regeneration facility, when the mixed ion exchange resin is transferred from the desalting tower to the regeneration tower of the regeneration facility, the temperature of the transfer water is constantly controlled to 25 ° C. or less. The method is characterized by using pure water.

The method for regenerating a cation exchange resin in a condensate desalination apparatus according to the present invention is a method for regenerating a cation exchange resin and an anion exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In the method of regenerating a mixed ion-exchange resin composed of a resin in a regeneration facility, when the mixed ion-exchange resin is separated into a cation-exchange resin and an anion-exchange resin in a cation-exchange resin regeneration tower, separation, backwashing water is always used. The method comprises using pure water whose temperature is controlled to not more than ° C.

Further, the method for regenerating a cation exchange resin in a condensate desalination apparatus according to the present invention provides a method for regenerating a cation exchange resin and an anion exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In the method of regenerating a mixed ion exchange resin composed of a 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 exchange resin is converted into a cation exchange resin regeneration tower. The method is characterized in that pure water whose temperature is constantly controlled to 25 ° C. or lower is always used as water for transferring an anion exchange resin which is passed through the inside of the cation exchange resin regeneration tower when the water is transferred from the to the anion exchange resin regeneration tower.

In the method for regenerating the ion exchange resin in the condensate desalination apparatus as described above, the heavy metal ions include copper ions and / or iron ions. In addition, as the cold pure water, pure water cooled by a cold water producing device such as a vapor compression refrigerator or an absorption refrigerator can be used. A deaerator such as a vacuum deaerator is usually attached to the condensate circulation system of the power plant.The deaerated water, which is the treated water of the vacuum deaerator, is used as deoxygenated cold pure water. Good.

The apparatus for regenerating an ion-exchange resin in a condensate-desalination apparatus according to the present invention uses a cation-exchange resin and an anion-exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. In the apparatus for regenerating the mixed ion exchange resin in the regeneration equipment, from the stage of transferring the mixed ion exchange resin from the desalting tower to the regeneration equipment, at least until immediately before the regeneration by passing the acid regenerant to the cation exchange resin And a means for supplying pure water whose temperature is constantly controlled to 25 ° C. or less as water for each step during the process.

In the method and apparatus for regenerating the ion exchange resin in the condensate desalination apparatus according to the present invention as described above, at least a part of the water in each step from the desalting tower to the regenerating facility is constantly used at 25 ° C. Since pure water whose temperature is controlled below, that is, cold pure water that has been forcibly cooled, is used, as shown in the results of Examples described later, elution of organic substances from the ion exchange resin is suppressed. Therefore, by suppressing the elution of the organic substances, the ion exchange performance of the anion exchange resin is prevented from lowering, and the water quality of the desalted water is maintained at a high purity. As a result of maintaining the quality of the desalinated water at high purity, it becomes possible to prevent corrosion of the boiler, steam generator, and the like in the power plant. Further, the method and apparatus for regenerating the ion exchange resin in the condensate desalination apparatus according to the present invention,
Basically, it can be carried out simply by using cold pure water, so that the desired ion exchange resin can be regenerated at low cost.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. Further, the effect of the present invention was confirmed by a test. FIG. 1 shows an example of ion-exchange resin regeneration equipment suitably used when performing the ion-exchange resin regeneration method in the condensate desalination apparatus of the present invention, and shows an example of a separation regeneration method. I have. FIG.
It is the graph which put together the result of the experiment performed in order to confirm the effect by this invention, and shows the elution situation of TOC (total organic carbon amount) from a cation exchange resin.

First, a description will be given of an ion-exchange resin regeneration facility suitably used in carrying out the method of regenerating the ion-exchange resin in the condensate desalination apparatus of the present invention, with reference to FIG. The ion exchange resin regeneration equipment used in the present invention (hereinafter, simply referred to as “regeneration equipment”) is a separation regeneration type regeneration equipment attached to a condensate desalination unit in a pressurized water nuclear power plant, for example. . As shown in FIG. 1, for example, this regeneration equipment 1 is a desalination tower 2 that constitutes a condensate
After receiving the mixed ion exchange resin 3 of the used cation exchange resin and the anion exchange resin to be regenerated, the mixed ion exchange resin 3 is separated into the cation exchange resin 3A and the anion exchange resin 3B, and the cation exchange resin 3A
Cation exchange resin regeneration tower (hereinafter, referred to as “first regeneration tower”) 4 for regenerating anion, and anion exchange resin regeneration for regenerating anion exchange resin 3B after receiving anion exchange resin 3B from first regeneration tower 4 The regenerated cation exchange resin 3A and the anion exchange resin 3B are received from the tower (hereinafter, referred to as a “second regeneration tower”) 5, the first and second regeneration towers 4, 5, and the empty degasser is received. A first resin storage tank 6 for temporarily storing the regenerated mixed ion exchange resin to be supplied to the salt tower 2 is provided. As will be described later, the present regeneration equipment 1 has a small particle size cation-exchange cation present near the separation interface between both ion-exchange resins during the previous separation operation of the mixed ion-exchange resin in the first regeneration tower 4. First, a small amount of mixed ion-exchange resin 3 composed of a resin and a large particle-size anion exchange resin
A second resin storage tank 7 is provided, which is extracted from the regeneration tower, received and temporarily stores the mixed ion exchange resin 3 until the next regeneration operation. In addition, 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 is formed to have a much smaller capacity. Have been.

A support plate 21 is provided in the lower part of the desalting tower 2, and the mixed ion exchange resin 3 is supported by the support plate 21. An air supply pipe 100 for supplying air and a water supply pipe 101 for supplying water such as condensate are connected to the upper part of the desalination tower 2, and cold pure water as defined in the present invention is supplied to the lower end thereof. A water supply pipe 22 to be supplied is connected to an air supply pipe 23 for supplying air (gas) and the like, and a valve (a reference number is omitted in FIG. 1; the same applies to the following valves) is also opened in a properly opened state. 2
2 supplies cold pure water as resin transfer water into the desalination tower 2;
Alternatively, if necessary, the cold pure water is supplied and air is supplied from the air supply pipe 100 so that the used mixed ion-exchange resin 3 in the desalination tower 2 is cooled with cold pure water, or with the water pressure and the air pressure. Of the first resin transfer pipe 8
To the first regenerating tower 4. Therefore, one end of the first resin transfer pipe 8 is inserted slightly above the support plate 21 in the desalination tower 2, and the other end is inserted into the upper end of the first regeneration tower 4. It communicates with the regeneration tower 4. 24 is a drain pipe.

A support plate 41 is provided in the lower part of the first regeneration tower 4, and supports the mixed ion exchange resin 3 transferred from the desalination tower 2 by the support plate 41. Further, a water supply pipe 42 and an air supply pipe 43 similar to those of the desalination tower 2 are connected to the lower end of the first regeneration tower 4. Cold pure water or air or both cold pure water and air are supplied into the first regenerator 4, and the mixed ion exchange resin 3 is scrubbed or backwashed in the first regenerator 4, and then cationized. The mixed ion exchange resin 3 is separated by utilizing the difference in specific gravity between the exchange resin 3A and the anion exchange resin 3B. In this separation operation, the interface between the cation-exchange resin 3A and the anion-exchange resin 3B cannot be separated clearly, and mixed ion-exchange resin in which both ion-exchange resins are mixed at the interface (shown by hatching in FIG. 1). A layer of resin 3 remains.

After completion of the above separation operation, the separated anion exchange resin 3B in the first regeneration tower 4 and the mixed ion exchange resin 3 thereunder are separated into second and third resin transfer pipes 9, 10 respectively.
The second resin transfer pipe 9 is sequentially transferred to the second regenerator 5 and the second resin storage tank 7 through the first regenerating tower 4. (The position at which only the exchange resin can be transferred), and the other end is inserted into the upper end of the second regeneration tower 5 to communicate between the first regeneration tower 4 and the second regeneration tower 5. Also, the third resin transfer pipe 1
0 has one end 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 connected to the upper end of the second resin storage tank 7. It is inserted into the section and communicates between the first regeneration tower 4 and the second resin storage tank 7.

A first distributor 44 is disposed 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 an acid such as sulfuric acid or hydrochloric acid supplied from the pipe 44A. The regenerant is supplied into the first regenerator 4 via the distributor 44 to regenerate the cation exchange resin 3A. Further, a second distributor 45 is disposed slightly above the first distributor 44, and a water supply pipe 46 and an air supply pipe 47 similar to the lower end of the tower are connected to the second distributor 45. Then, by supplying pure water (cold pure water may be used) to the first regeneration tower 4 through the second distributor 45 with the valve of the pipe 46 appropriately opened, the regenerant is passed. The subsequent cation exchange resin 3A is washed and discharged from the drain pipe 48 below the first regeneration tower 4 as washing wastewater. The second distributor 45 acts as a collector during the above-described backwashing and separating operations, and the second distributor 45 allows the backwash water,
Separation water is collected and discharged from a drain pipe 49 above the first regeneration tower 4.

Further, after the regeneration of the cation exchange resin 3A, 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.
1, the fourth resin transfer pipe 11 has one end inserted slightly above the support plate 41 in the first regeneration tower 4 and the other end connected to the upper end of the first resin storage tank 6. The first regeneration tower 4 and the first resin storage tank 6 communicate with each other.

Since the second regeneration tower 5 for regenerating the anion exchange resin 3B is constructed in accordance with the first regeneration tower 4, the same reference numerals as those in the first regeneration tower 4 are used in FIG. Tower 5
Only the features of will be described. In the second regeneration tower 5, an alkali regenerant such as sodium hydroxide supplied from a pipe 54A through a first distributor 54 is supplied to the anion exchange resin 3B, and the anion exchange resin transferred from the first regeneration tower 4 is supplied. 3B is reproduced. Also, the second
Pure water or a gas such as pure water and air can be supplied into the second regeneration tower 5 from a water supply pipe 52 and a gas supply pipe 53 at the lower part of the regeneration tower 5.
A similar water supply pipe 56 and gas supply pipe 57 are connected to the distributor 55. After the regeneration of the anion exchange resin 3B, an operation of transferring the regenerated anion exchange resin 3B in the second regeneration tower 5 from the second regeneration tower 5 to the first resin storage tank 6 via the fifth resin transfer pipe 12 is performed. Do,
For this reason, one end of the fifth resin transfer pipe 12 has the support plate 51.
Is inserted slightly up, and the other end is connected to the fourth resin transfer pipe 11.
And the anion exchange resin 3B in the fifth resin transfer pipe 12 merges with the regenerated cation exchange resin 3A transferred from the first regeneration tower 4 and is transferred to the first resin storage tank 6. . Incidentally, 58 and 59 are drain pipes.

At the lower end of the first resin storage tank 6, a first distributor 61 is disposed. Further, a water supply pipe 62 and an air supply pipe 63 are connected to the first distributor 61, and valves of the respective pipes 62, 63 are connected. Is opened to supply pure water or pure water and air into the first resin storage tank 6. A second distributor 64 is provided at the upper end of the first resin storage tank 6.
Is connected to a water supply pipe 65, and the valve of the pipe 65 is opened to supply pure water into the first resin storage tank 6. The first resin storage tank 6 is connected to the upper end of the desalination tower 2 via the sixth resin transfer pipe 13, and acts on pure water supplied from the water supply pipe 62 and the gas supply pipe 63 or between pure water and air pressure. Thus, the regenerated mixed ion exchange resin 3 in the first resin storage tank 6 is transferred to the desalination tower 2.
Incidentally, 66 and 67 are drain pipes.

The second resin storage tank 7 is configured in accordance with the first resin storage tank 6, and a first distributor 71 is disposed at a lower end in the second resin storage tank 7. A water supply pipe 72 and an air supply pipe 73 are connected, and a second distributor 74 is provided at an upper end of the second resin storage tank 7.
Is connected to a water supply pipe 75. 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 cold pure water supplied from the water supply pipe 72 and the air supply pipe 73. As transfer water,
Alternatively, a small amount of the mixed ion exchange resin 3 previously stored in the second resin storage tank 7 is combined with the mixed ion exchange resin 3 from the desalting tower 2 by the action of air pressure using cold pure water as transfer water, if necessary. To the first regeneration tower 4. Reference numerals 76 and 77 denote drain pipes.

In the present embodiment, of the water supply pipes in the regenerating facility configured as described above,
3, 42, 72 can be supplied with cold pure water. The cold pure water is pure water whose cooling is constantly controlled to a temperature of 25 ° C. or lower, and in the present embodiment, is supplied from a cold water producing apparatus 200 such as a refrigerator.
Further, if the cold water producing apparatus 200 is installed at a stage subsequent to the deaerator 201, deaerated cold pure water can be obtained, which is more preferable. The temperature monitoring device for controlling the temperature may be provided alone or in plural at an arbitrary position of the regeneration equipment 1, but is preferably provided at a subsequent stage of the cold water production device 200.

Next, one embodiment of the method for regenerating an ion exchange resin of the present invention using the present regeneration equipment will be described. When condensate is passed through the condensate desalination unit and the mixed ion exchange resin 3 in one of the desalination towers 2 reaches the end of water passage, a metal oxide such as iron oxide is added to the mixed ion exchange resin 3. The main clad is adhered, and a large amount of impurity cations such as hydrazine, Na ion, Fe ion, and Cu ion are adsorbed on the cation exchange resin 3A, and Cl ion, SO ₄ ion, etc. are adsorbed on the anion exchange resin 3B. A large amount of impurity anions are adsorbed. The temperature in the desalination tower 2 at the end of the passing water is usually 30 ° C. or higher, but the cold pure water is used for transferring the used mixed ion exchange resin 3. (In some plants, the temperature around the desalination tower is not monitored.
It is known that this is the case. )

That is, 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 via the first resin transfer pipe 8, and A small amount of the mixed ion exchange resin 3 stored in the second resin 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, the water supply pipe 22 is connected to the desalination tower 2.
Cold pure water alone or cold pure water is supplied from the water supply pipe 22 and air is supplied from the gas supply pipe 100. In the second resin storage tank 7, cold water is supplied from the water supply pipe 72 into the second resin storage tank 7. Pure water alone or cold pure water and air are supplied simultaneously from both the water supply pipe 72 and the air supply pipe 73 in the upward flow. When cold pure water and air are simultaneously supplied into the second resin storage tank 7, cold pure water may be supplied from the lower end and air may be supplied from the upper end as in the case of the desalination tower 2.

At the time of the above-mentioned transfer, when pure cold water is used alone, the pure cold water becomes the transfer water of the mixed ion exchange resin 3, and the water pressure becomes the driving force. When cold pure water and air are supplied at the same time, the cold pure water serves as the transfer water for the mixed ion exchange resin 3, and the air pressure serves as 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 cold pure water or cold pure water and air, the mixed ion exchange resin 3 is kept in a low temperature state. Therefore, during the transfer, the cation exchange resin 3A suppresses the generation of hydrogen peroxide due to the oxidation of hydrazine catalyzed by heavy metal ions such as Cu ions, thereby suppressing the oxidative decomposition of the mixed ion exchange resin 3, Elution of organic substances such as molecular polymers can be suppressed.

The used mixed ion exchange resin 3 is transferred from the desalting tower 2 into the first regenerating tower 4, and after the desalting tower 2 is emptied, the pre-regenerated mixed resin in the first resin storage tank 6 is regenerated. The ion exchange resin 3 is transferred to the desalination 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 air supply pipe 63 to supply the pure water. (1) The mixed ion exchange resin 3 in the resin storage tank 6 is transferred into the desalination tower 2. In this transfer stage, since the mixed ion exchange resin 3, particularly the cation exchange resin 3A, does not adsorb impurities such as hydrazine and heavy metal ions, the oxidative decomposition of hydrazine is extremely high even when the temperature of the cation exchange resin 3A and the surrounding water is high. Therefore, it is not necessary to use cold pure water, and normal pure water may be used.

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 cold pure water used as the transfer water flows out of the drain pipe 48 by opening the drain pipes 48 and 49, and flows out of the drain pipe 49 when the air is used as the driving force of the transfer water. I do.
Then, when all the used mixed ion exchange resins 3 are filled in the first regeneration tower 4, the supply of cold pure water or cold pure water and air from the desalination tower 2 is stopped. As a result, the mixed ion exchange resin 3 is kept at a low temperature in the first regeneration tower 4, and the oxidative decomposition of the mixed ion exchange resin 3, especially the cation exchange resin 3A can be suppressed at this stage also for the above-described reason.

Next, in the first regeneration tower 4, if necessary,
Cold pure water is supplied in an upward flow from the water supply pipe 42 to immerse the mixed ion-exchange resin 3 in the cold pure water.
To perform a scrubbing operation to physically separate the clad of metal oxide or the like adhering to the surface of the mixed ion exchange resin 3. After this peeling operation, the supply of air is stopped, cold pure water is supplied in an upward flow from the water supply pipe 42 to backwash the mixed ion exchange resin 3, and the peeled clad is discharged from the drain pipe 49 together with the washing water. . After the clad discharge, the backwashing is continued with cold pure water to separate the mixed ion exchange resin 3, and the cation exchange resin 3A is separated to the lower side and the anion exchange resin 3B is separated to the upper side. In this series of operations, since cold pure water is used, both ion exchange resins are in a low temperature state, and there is no possibility that both ion exchange resins are oxidatively decomposed for the above-described reason.

After the separation operation of the mixed ion exchange resin 3, the first
Cold pure water is supplied from the water supply pipe 42 at the lower part of the regeneration tower 4 into the first regeneration tower 4 in an upward flow, or cold pure water is supplied from the water supply pipe 42 and the air supply pipe at the upper part of the first regeneration tower 4. When air is supplied simultaneously from 47, the cold pure water becomes the transfer water, or the cold pure water becomes the transfer water and the air pressure becomes the driving force,
All of the upper anion exchange resin 3B is transferred to the second regeneration tower 5 via the second resin transfer pipe 9. Subsequently, all of the mixed ion exchange resin 3 in the middle layer is transferred to the second resin storage tank 7 via the third resin transfer pipe 10 in accordance with the transfer operation of the anion exchange resin 3B. The first in these transfer operations
Since cold pure water is used as transfer water passing through the lower cation exchange resin 3A in the regeneration tower 4, there is no possibility that the cation exchange resin 3A is oxidatively decomposed for the above-described reason.

After the upper anion exchange resin 3B and the middle mixed ion exchange resin 3 are transferred from the first regeneration tower 4 as described above, the first anion exchange resin 3B is connected to the first regeneration tower 4 via a pipe 44A.
After supplying an acid regenerant such as hydrochloric acid or 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 the H-type cation exchange resin 3A, Pure water is supplied from the first distributor 44 through the pipe 44A to extrude 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 operation of regenerating the cation exchange resin 3A is completed. When passing the acid regenerant,
The hydrazine adsorbed on the cation exchange resin 3A does not undergo autooxidative decomposition because the inside of the cation exchange resin layer is in the acidic region due to the passage of the acid regenerant, and there is no fear of oxidative decomposition of the cation exchange resin 3A. It is not necessary that the dilution water used is necessarily pure cold water.

In the first regenerating tower 4, if metal oxide remains on the surface of the cation exchange resin 3A after the passage of the acid regenerant, the adhered substance is peeled off by scrubbing backwashing. Since hydrazine has already been desorbed from the cation exchange resin 3A and heavy metal ions serving as a catalyst have also been desorbed at the same time, the cation exchange resin 3A does not generate hydrogen peroxide. Therefore, it is not necessary to use cold pure water in the scrubbing backwash operation at this point.
However, in consideration of general oxidation by oxygen, it is preferable to use cold pure water for all operations.

In parallel with the above-mentioned regeneration operation of the cation exchange resin 3A, in the second regeneration tower 5, the same operation as in the case of the first regeneration tower 4 is performed, and the second regeneration tower 5 is introduced into the second regeneration tower 5 through the first distributor 54. An alkali regenerant such as an aqueous sodium hydroxide solution is supplied, and Cl ions and SO ₄ ions adsorbed on the used anion exchange resin 3B are desorbed to remove OH.
After regenerating as the anion exchange resin 3B, the operation of regenerating the anion exchange resin 3B is completed through an extrusion step and a washing step. In this alkali regeneration operation, hydrazine and heavy metal ions do not exist, and there is no need to consider the generation of hydrogen peroxide due to hydrazine, so the regeneration operation should be performed using almost room temperature pure water as in the past. No need to use cold pure water.

Thereafter, the regenerated cation exchange resin 3A
And anion exchange resin 3B from first and second regeneration towers 4 and 5 to first resin storage tank 4 and fourth and fifth resin transfer pipes 11 and 12.
Transport through. In this transfer, hydrazine and heavy metal ions have already been removed as described above, so there is no need to use cold pure water for resin transfer, and as in the conventional operation, normal pure water or normal pure water is used. Both ion exchange resins 3A and 3B can be transferred using air.

In the case of the single-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 performed. Is basically the same as in the case of the above-mentioned separation and regeneration method, and therefore, may be carried out using cold pure water in accordance with the above-mentioned separation and regeneration method. In the case of the single-column regeneration method, the mixed ion-exchange resin is separated and a cation exchange resin layer is formed on the lower side and an anion exchange resin layer is formed on the upper side. The agent is supplied in an upward flow to regenerate the cation exchange resin, and the alkali regenerant is supplied to the upper layer anion exchange resin to regenerate the anion exchange resin. Discharge via installed collector. Otherwise, operations such as resin transfer are performed according to the separation and regeneration method.

As described above, according to the above embodiment, when regenerating the mixed ion exchange resin 3 used by the desalination treatment of condensate containing hydrazine and heavy metal ions,
From the stage of transferring the used mixed ion exchange resin 3 from the desalting tower 2 to the regeneration facility 1, at least the cation exchange resin 3
Until immediately before the regeneration by passing the acid regenerant into A, cold pure water was used, so the minimum required cold pure water was used, and cold pure water and nitrogen were used in all regeneration processes. Compared to the case where gas is used, the amount of cold pure water or nitrogen gas used can be reduced, and the regeneration operation can be performed at low cost. Since cold pure water is used during the above period, hydrazine adsorbed on the used cation exchange resin 3A is not oxidized by the catalytic action of heavy metal ions such as Fe ions and Cu ions adsorbed on the resin. Suppressed, therefore, the production of hydrogen peroxide is suppressed, thereby preventing oxidation of the mixed ion exchange resin 3, particularly the cation exchange resin 3A,
Elution of an organic substance such as a high molecular polymer from the cation exchange resin 3A can be reliably prevented.

In the regenerated mixed ion-exchange resin 3 obtained by the above-described regenerating method, since the mixed ion-exchange resin 3 does not contain an organic substance such as a high-molecular polymer, a steam generator is used during the desalination process. The eluted organic matter is not brought into the steam generator or the like, so that the generation of SO ₄ ions due to the organic matter in the steam generator or the like can be prevented, and thus the corrosion of the steam generator or the like can be prevented. Furthermore, the ion exchange performance of the anion exchange resin 3B during the desalination treatment suppresses the elution of organic substances from the cation exchange resin, prevents the leakage of Cl ions, SO ₄ ions, etc., and improves the water quality of the desalination treatment water with high purity. Can be maintained.

In order to confirm the effect of using the cold pure water as the water as described above, the following experiment was conducted. In this experiment, particularly, the relationship between the organic matter generated from the cation exchange resin on which hydrazine and heavy metal ions were adsorbed and the temperature of the water was investigated.

Experiments 1 to 5 "Amberlite" (registered trademark: manufactured by Rohm & Haas) 200CP, which is a strongly acidic cation exchange resin obtained by sulfonating a copolymer of styrene and divinylbenzene, was packed in a column. A 2.5% aqueous solution of hydrazine in which 98% hydrazine (commercially available) is dissolved is passed through the column,
A cation exchange resin in which hydrazine was adsorbed at a ratio of about 50 to 80 g / L-resin (hereinafter referred to as "hydrazine adsorption type exchange resin") was prepared.

The hydrazine-adsorbing exchange resin is packed in another column, and an aqueous solution in which ferrous sulfate and copper sulfate reagents (commercially available) are dissolved is passed through the column to adsorb hydrazine. A cation exchange resin (hereinafter, referred to as "heavy metal ion-hydrazine adsorption type exchange resin") in which Fe ions were adsorbed at a rate of about 600 mg / L-resin and Cu ions were adsorbed at a rate of about 300 mg / L-resin was prepared.

In addition, five containers made of tetrafluoroethylene resin containing 300 mL of pure water were prepared, and 100 mL of the above heavy metal-hydrazine adsorption type exchange resin was charged into each container. C., 25.degree. C., 20.degree. C., and 10.degree. C., and the heavy metal-hydrazine adsorption type exchange resin in each container was constantly stirred by a constant temperature shaker (Experiment 1-1 to Experiment 5-1). ). In addition, hydrogen ion exchange resin (untreated cation exchange resin) is put in the water of the other container, and the same is applied at 40 ° C, 30 ° C, 25 ° C, 20 ° C, and 10 ° C.
And the untreated cation exchange resin in each container was constantly stirred with a constant temperature shaker (Experiment 1-2 to Experiment 5-2). And in each experiment, 2
Four hours later, water in each container is collected and its TOC concentration (m
gC / L), and the state of elution of organic substances from the heavy metal-hydrazine adsorption type exchange resin was observed.

Even in the absence of heavy metal-hydrazine, the elution TOC increases as the temperature increases, so that the untreated resin is stirred in water at each temperature in the same manner to elute T.
The OC was measured, and the amount of elution of the hydrogen ion exchange resin (the untreated resin elution amount) was subtracted from the amount of elution from the heavy metal-hydrazine adsorption exchange resin to reveal the amount of oxidation degradation suppression in the heavy metal-hydrazine adsorption exchange resin. did. The measurement results of each experiment are shown in FIG. FIG. 2 shows the relationship between the elution temperature and the TOC (total organic carbon) concentration.

The experimental conditions are as follows. Experiment 1-1: Heavy metal-hydrazine adsorption type exchange resin at 40 ° C.
Was shaken. Experiment 1-2: The untreated cation exchange resin was shaken at 40 ° C. Experiment 2-1: A heavy metal-hydrazine adsorption type exchange resin was heated to 30 ° C.
Was shaken. Experiment 2-2: Untreated cation exchange resin was shaken at 30 ° C. Experiment 3-1: Heavy metal-hydrazine adsorption type exchange resin at 25 ° C
Was shaken. Experiment 3-2: The untreated cation exchange resin was shaken at 25 ° C. Experiment 4-1: A heavy metal-hydrazine adsorption type exchange resin at 20 ° C.
Was shaken. Experiment 4-2: The untreated cation exchange resin was shaken at 20 ° C. Experiment 5-1: A heavy metal-hydrazine adsorption type exchange resin was heated at 10 ° C.
Was shaken. Experiment 5-2: The untreated cation exchange resin was shaken at 10 ° C.

In the results of the above experiments, Experiment 1-2, Experiment 2-2, Experiment 3-2, Experiment 4-2, and Experiment 5-2 show that the untreated (new or regenerated) cation exchange resin was replaced with pure water. This corresponds to the case of contact. The TOC detected in these cases is due to leakage of organic substances originally present in the cation exchange resin, and depends on the temperature, and is oxidatively degraded by hydrogen peroxide generated by heavy metals, hydrazine, and dissolved oxygen. Therefore, it can be regarded as a so-called blank value.

As described above, the cation exchange resin adsorbing hydrazine and heavy metal ions generates hydrogen peroxide upon contact with dissolved oxygen, and the reaction for accelerating the oxidative deterioration of the cation exchange resin is accelerated by temperature. When the resin is transferred from the desalting tower to the regeneration tower at 25 ° C to 40 ° C using pure water with almost saturated air and dissolved oxygen concentration as in the conventional method, hydrazine is self-oxidized by the action of heavy metal ions. It decomposes and further produces hydrogen peroxide due to dissolved oxygen, which causes oxidative deterioration of the ion exchange resin. To completely prevent oxidative deterioration of the cation exchange resin,
Basically, it is necessary to transfer and regenerate without contact with oxygen, but to completely shut off it requires new nitrogen piping equipment and monitoring of dissolved oxygen. In the case of regenerating a cation exchange resin adsorbing hydrazine and heavy metal ions, as in the present invention, for example, when transferring the resin from a desalting tower to a regenerating tower, a cold carrier whose temperature is constantly controlled to 25 ° C. or lower is used as a carrier. It can be seen that oxidative degradation can be easily suppressed by using pure water or cold pure water up to the backwashing separation operation, which is performed before passing the acid regenerant through the cation exchange resin in the regeneration tower. Was. After passing the drug, hydrazine, heavy metals and the like have been removed from the cationic resin, so that there is no problem even when used at a normal temperature.

The cold pure water may be cooled by any method, and a general refrigerator can be used. The cold pure water used may not be highly purified as long as it is clear enough not to contaminate the ion exchange resin, but the electrical conductivity is about 1 mS / m (25 ° C), Those having a dinium ion concentration of 1 μg / l or less are preferred.

[0063]

As described above, according to the first aspect of the present invention, the elution of organic substances from an ion exchange resin, particularly a cation exchange resin, can be performed in both the separation regeneration system and the single column regeneration system. It can prevent the deterioration of the ion exchange performance of the anion exchange resin and prevent the corrosion of the boiler, steam generator, etc. It is possible to provide a method of regenerating an ion exchange resin in a condensate desalination apparatus that can be regenerated at low cost.

According to the invention of claim 2 of the present application,
In either case of the separation regeneration method and the single tower regeneration method,
When transferring the mixed ion exchange resin from the desalting tower to the regeneration tower of the regeneration equipment, it is possible to prevent deterioration of the cation exchange resin, prevent elution of organic substances from the cation exchange resin, and perform ion exchange of the anion exchange resin. Regeneration of ion exchange resin in condensate desalination equipment that can prevent deterioration in performance and, consequently, maintain the quality of desalinated water at high purity and prevent corrosion of boilers, steam generators, etc. A method can be provided.

According to the third aspect of the present invention,
In either case of the separation regeneration method and the single tower regeneration method,
When separating the mixed ion-exchange resin into a cation-exchange resin and an anion-exchange resin in the cation-exchange resin regeneration tower, it is possible to prevent deterioration of the cation-exchange resin, prevent elution of organic substances from the cation-exchange resin, and anion. In the condensate desalination device, it is possible to prevent the ion exchange performance of the exchange resin from deteriorating, and thus to maintain the quality of the desalinated water at high purity and prevent the corrosion of boilers, steam generators, etc. A method for regenerating an ion exchange resin can be provided.

According to the invention of claim 4 of the present application,
After separating the mixed ion exchange resin into the cation exchange resin and the anion exchange resin in the cation exchange resin regeneration tower in the separation regeneration method, when transferring the anion exchange resin from the cation exchange resin regeneration tower to the anion exchange resin regeneration tower, It can prevent the deterioration of the cation exchange resin, prevent the elution of organic substances from the cation exchange resin, and prevent the ion exchange performance of the anion exchange resin from deteriorating. The present invention can provide a method for regenerating an ion exchange resin in a condensate desalination apparatus capable of preventing corrosion of a boiler, a steam generator, and the like while maintaining the same.

According to the invention of claim 5 of the present application,
In any of the above inventions, when the heavy metal ion is a copper ion and / or an iron ion, the copper ion and / or the iron ion
Alternatively, a condensate desalination device that prevents the production of hydrogen peroxide due to the oxidation of hydrazine catalyzed by iron ions, thereby preventing the oxidative decomposition of ion exchange resins and preventing the elution of organic substances such as high molecular polymers. A method for regenerating the ion exchange resin in the inside can be provided.

According to the invention of claim 6 of the present application,
In any of the above inventions, the use of pure water degassed in cold pure water can more reliably prevent the elution of organic substances.

Further, according to the invention of claim 7 of the present application, it is possible to provide an apparatus for regenerating an ion exchange resin in a condensate desalination apparatus, which can easily carry out the method according to the present invention as described above. .

[Brief description of the drawings]

FIG. 1 is a system diagram of an ion exchange resin regeneration device in a condensate deionization device according to an embodiment of the present invention.

FIG. 2 is a graph showing the results of an experiment performed to confirm the effect of the present invention, and is a graph showing the relationship between immersion temperature (water temperature) and TOC.

[Explanation of symbols]

 Reference Signs List 1 regeneration equipment 2 desalination 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 pipe 9 2nd resin transfer pipe 10 3rd resin transfer pipe 11 4th resin transfer pipe 12 5th resin transfer pipe 13 6th resin transfer pipe 14 7th resin transfer pipe 22, 42, 72 water supply piping 200 cold water production equipment 201 deaerator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G21F 9/12 512 G21F 9/12 512K F term (Reference) 4D025 AA07 AB07 AB08 AB09 AB14 AB18 AB22 AB23 BA09 BA14 BA22 BB04 BB15 BB18 CA08 CA10

Claims (7)

[Claims] 1. A method for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin in a regeneration facility, which is used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. From the stage of transferring the exchange resin to the regeneration equipment from the desalting tower, at least until immediately before the regeneration by passing the acid regenerant through the cation exchange resin, the temperature is constantly controlled to 25 ° C. or less as water for each step. A method for regenerating an ion exchange resin in a condensate desalination apparatus, characterized by using purified water. 2. A method for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions in a regeneration facility. When transferring the exchange resin from the desalting tower to the regenerating tower of the regenerating facility, pure water whose temperature is constantly controlled to 25 ° C. or less is used as the transfer water, How to regenerate exchange resin. 3. A method for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions in a regeneration facility. When the exchange resin is separated into cation exchange resin and anion exchange resin in the cation exchange resin regeneration tower, it is always used as separation and backwash water.
A method for regenerating an ion-exchange resin in a condensate demineralizer, wherein pure water whose temperature is controlled to 25 ° C. or lower is used. 4. A method for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin used in a desalination tower for treating condensate containing hydrazine and heavy metal ions in a regeneration facility. After separating the exchange resin into a cation exchange resin and an anion exchange resin in the cation exchange resin regeneration tower, when transferring the anion exchange resin from the cation exchange resin regeneration tower to the anion exchange resin regeneration tower, the A method for regenerating an ion-exchange resin in a condensate desalination apparatus, wherein pure water whose temperature is constantly controlled to 25 ° C. or less is used as water for transferring an anion-exchange resin to be passed. 5. The method for regenerating an ion exchange resin in a condensate desalination apparatus according to claim 1, wherein the heavy metal ions are copper ions and / or iron ions. 6. The ion in the condensate desalination apparatus according to claim 1, wherein the pure water whose temperature is constantly controlled to 25 ° C. or less is deaerated pure water. How to regenerate exchange resin. 7. An apparatus for regenerating a mixed ion exchange resin comprising a cation exchange resin and an anion exchange resin in a regeneration facility, which is used in a desalination tower for treating condensate containing hydrazine and heavy metal ions. From the stage of transferring the exchange resin to the regeneration facility from the desalting tower, at least 25 ° C. or less was always used as water for each step from immediately before the regeneration by passing the acid regenerant through the cation exchange resin. An apparatus for regenerating an ion-exchange resin in a condensate desalination apparatus, comprising: means for supplying pure water.