JP2003236540A - Method of improving water quality in desalination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of improving water quality in a desalination apparatus in which only physically sound resin particles in a granular ion exchange resin used for the desalination apparatus are used and the leakage of the fine resin or crushed resin to the treated water is prevented to improve the water quality of treated water. <P>SOLUTION: Before being filled in the desalination apparatus, only the sound resin particles are secured by applying a 1st process of housing in a vessel filled with water and crushing the resin particles having internal strain or fine crack by a crushing means and a 2nd process for removing the crushed resin particles from the crush treated material in the 1st process by a separating means and the resin particles free from the fine resin particles or crushed resin particles are offered to the desalination apparatus to improve the quality of the treated water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ion-exchange resin used in a desalting apparatus, which efficiently removes resin particles having latent defects existing in the resin particles, thereby physically sounding the resin particles. The present invention relates to a water passing method of a desalination device for maintaining and preventing leakage of fine resin particles and crushed resin particles (including particle fragments) into treated water to improve the quality of treated water.

[0002]

2. Description of the Related Art When ion-exchange resin particles are packed in a desalting apparatus to perform water-flow operation, first, the cation-exchange resin particles and / or anion-exchange resin particles to be packed are loaded into a desalting tower or a regenerating tower. Fill with water. Then, water is filled up to a level exceeding the level of the ion exchange resin particles contained in the tower, air is injected from the lower part of the tower, the ion exchange resin particles are stirred, and the fine resin particles and the crushed resin present in the resin particle mixture are stirred. The particles are released in water. Next, backwash water is injected from the lower part of the tower to fully develop the resin layer, and the fine resin particles and the crushed resin particles that have come out to the upper part of the resin layer are overflowed and discharged to the outside of the system. Repeat this operation multiple times,
The fine resin particles and the crushed resin particles in the resin layer are removed.
After the resin particles are mixed and transferred to the desalting tower, the water passage operation of the desalting tower is started. In the case of directly filling the desalting tower with the resin particles, all the above-mentioned operations are carried out in the desalting tower to start the water passage operation.

[0003]

In the method of filling the desalting apparatus with the ion exchange resin and supplying it to the water-flowing operation, there are latent defects such as internal strain and fine cracks mixed in the sound ion-exchange resin particles. It is impossible to completely remove the ion-exchange resin particles having. Therefore, if backwash regeneration, replenishment regeneration, accompanying resin transfer, water sampling operation, etc. are continuously continued, there is a possibility that ion-exchange resin particles with potential defects will be crushed during the process. high. These crushed resin particles are difficult to remove sufficiently by normal backwash regeneration, and they leak to the downstream side due to the differential pressure applied to the resin layer during water flow operation and the transient impact at the time of introducing the desalting tower. , There is a risk of worsening the treated water.

The present invention has been made in view of the above circumstances, and regarding ion exchange resin particles used in a desalting apparatus, resin particles having latent defects existing in the resin particles can be efficiently used. A method for improving the water quality of a desalination device for removing water, maintaining physically sound resin particles, preventing leakage of fine resin particles and crushed resin particles into treated water, and improving the quality of treated water. Is.

[0005]

Means for Solving the Problems As a result of various studies to achieve the above object, the present inventors have selected cation exchange resin particles and / or anion exchange resin particles to be used in a desalting apparatus. Before being subjected to water operation, a first process in which a physical and / or chemical crushing action is applied to the resin particles in advance to crush only the resin particles having potential defects such as internal strain and fine cracks. Then, by removing the resin particles crushed in the first process from the sound resin particles by the second process, the resin particles having potential defects are not included, and the sound resin particles are filled in the desalination apparatus and collected. By carrying out water operation, the inventors have invented a method for improving the water quality by eliminating the generation of fine resin particles and crushed resin particles over time.

In the above-mentioned first process, the cation exchange resin particles and / or the anion exchange resin particles used in the desalting apparatus are stored in a container filled with water before the water sampling operation, Circulation operation with a pump, agitation with an agitator, etc.
Alternatively, a physical crushing means for transmitting ultrasonic waves intermittently or continuously for 30 minutes or more, a crushing means by a thermal stress of pouring water after heating the ion exchange resin to such an extent that functional groups are not decomposed by a dryer, or , The resin is a regenerant, hydrochloric acid,
After immersing in a relatively high-concentration chemical such as sulfuric acid, nitric acid, caustic soda, or salt, wash it thoroughly with pure water. It crushes resin particles that have defects.

Further, in the above-mentioned second process, the resin particles crushed by the first process are back-washed at a development rate of 100% or more, preferably 200% for 30 minutes or more after scrubbing with air or nitrogen gas, By means of removing by overflow, or in a dry state, or by introducing resin particles together with water into a vibrating sieve or the like continuously or in a batch, and by means of sieving out crushed resin particles, crushed resin particles from healthy resin particles Is efficiently removed.

In the present invention, the state of the ion exchange resin particles is confirmed in advance by observing the sampled resin particles with a microscope or the like, and the optimum crushed resin particle removing means is determined by the above-mentioned first process and second process. Select from the
It is intended to provide a method for effectively and economically improving water quality by eliminating the generation of fine resin particles and crushed resin particles when a desalting apparatus is used over time, which is characterized by being combined.

Further, according to the present invention, the respective means of the first process and the respective means of the second process are incorporated in advance in the resin filling step of the operation of operating the desalination apparatus so that they can be linked to the operation of the desalination apparatus. , It is possible to improve the water quality by eliminating the generation of fine resin particles and crushed resin particles during the time-dependent use of the desalting device, which is characterized by controlling the operation by using a sequencer or a program timer to automatically operate these. It provides a way to try. An apparatus specifically embodying the present invention imparts physical and / or chemical crushing action to cation-exchange resin particles and / or anion-exchange resin particles to prevent latent defects such as internal strain and fine cracks. Healthy resin particles that do not contain resin particles having latent defects by the first process of crushing only the resin particles that they have and the second process that removes the resin particles crushed in the first process from the sound resin particles The desalination apparatus is characterized by being filled with.

Further, according to the present invention, not only new ion-exchange resin particles but also resin particles used for a long time in a desalting device are sampled and subjected to a strength test, and as a result, a decrease in physical strength is confirmed. Applies to ion exchange resin particles (average load strength of 60 regenerated resin particles measured by Chatillon meter: 350 g / particle or less, ratio of 200 g / particle or less 5% or more) to ensure only healthy resin particles without potential defects Then, by filling the desalting apparatus and performing a water sampling operation, the generation of fine resin particles and crushed resin particles during extended life is eliminated, and a method for improving water quality is provided. The ion exchange resin treated in the present invention is a granular one,
The resin particles are treated as resin particles, and the particle diameter of the resin particles is usually 0.35 to 1.2 mm.

[0011]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

Embodiment 1 1. Preparation of sample A plurality of commercially available strongly acidic gel type cation exchange resin particles are immersed in pure water, mixed well, and 1 to 2 ml is sampled from the mixture, and about 2
The sphericity is measured by observing 000 to 4000 grains. The sphericity is expressed as the ratio of healthy spheres (uncracked and uncrushed spheres) to the total number of observed ion-exchange resin particles. Further, the recognition of the crack sphere was performed by combining the transmitted light from below the particle, the reflected light from above, and the tilted light to the particle, and minute cracks that were not normally recognized were also detected and counted as crack spheres. As a result, the sphericity was calculated as shown in Table 1 below.

[0013]

[Table 1]

2. First Process (Fracture Process of Crack Particles) With respect to Samples A, B, and C prepared as shown in Table 1 above, the fracture test of crack balls was performed as follows.

A. Pump circulation method / test method Approximately 30 cm in length at the outlet and inlet of the magnetic pump 1,
A silicone rubber tube 2 having an inner diameter of 9 mm was fitted and both ends thereof were put in a 500 ml plastic beaker 3 and fixed so that the resin slurry could easily circulate as described below. The resin particles were transferred into the beaker 3 together with water, the slurry was circulated, and the cracked spheres (particles) were crushed by abrasion between the resin particles and by the pump impeller. The resin was appropriately sampled during the circulation operation, and the ratio of crack spheres and crushed resin particles was measured. The test conditions are shown in Table 2.

[0016]

[Table 2]

Test results Pump A circulation operation was performed for samples A, B and C for 30 minutes, resin was sampled every 10 minutes, and the results of measuring the ratio of cracked spheres, crushed spheres and healthy spheres are shown below. It shows in Tables 3-5.

[0018]

[Table 3]

[0019]

[Table 4]

[0020]

[Table 5]

In all cases, the crack spheres are significantly reduced to below 0.2% and, instead, the crushed spheres are increased. The increased crushed spheres could be removed by backwash overflow or vibrating sieving in the following second process, and only healthy spheres could be secured. In addition to the above-mentioned pump circulation method, the method of crushing cracked spheres uses resin regeneration agents (sulfuric acid, hydrochloric acid,
The osmotic shock method of immersing in caustic soda, etc., the thermal stress shock method of heating the resin and then pouring water, and a combination of these methods are considered. As a further example, the osmotic shock method + pump circulation method will be described.

B. Osmotic shock method + pump circulation method / test method In the same manner as in the preparation of the sample described above, commercially available strong acid gel type cation exchange resin particles are immersed in pure water,
The sphericity was measured. This is sample D. The measurement results are shown in Table 6.

[0023]

[Table 6]

The prepared sample D had a relatively large proportion of crack spheres (also confirmed a latent crack that could not be detected by conventional inspection), and it is expected that the crushing of crack spheres will not be sufficient only by the pump circulation method. Therefore, the combination method with the osmotic shock method was applied.

First, 40 ml of the above sample D was thoroughly drained, put in a beaker containing about 30 wt% sulfuric acid, and stirred for 30 minutes. Then, after calming for about 5 minutes, sulfuric acid is discharged. Further, 25 times the amount of pure water of the resin was poured all at once into a beaker and stirred for 30 minutes as it was, then the resin particles were separated from the liquid and washed with water, and the sphericity of the resin particles was measured. Next, the resin particles are subjected to the above-mentioned pump circulation method,
The slurry was circulated and the cracked spheres were crushed due to abrasion between the resins and the pump impeller. The resin was appropriately sampled during the circulation operation, and the ratio of crack spheres and crushed resin was measured. The test conditions are shown in Table 7.

[0026]

[Table 7]

The test conditions of the pump circulation method are the same as those described in the item a). -Test results Sample D was subjected to the osmotic shock method + pump circulation method, the resin particles were sampled in each step, and the results of measuring the ratio of crack spheres, crushed spheres and healthy spheres are shown in Table 8 below. And Table 9 shows.

[0028]

[Table 8]

[0029]

[Table 9]

The crack spheres of sample D had a value of 7.0% to 0.
It was greatly reduced to 1%, and instead, the number of crushed spheres increased as described above. The number of crushed balls increased is the second
Only healthy spheres could be secured by removing by backwash overflow or vibrating sieve in the process.

3. The above-mentioned samples A, B, which were subjected to the crushing test of the second process crack sphere,
For C and D, a crushed ball separation test was performed.

C. Backwash separation method / test method 40m each of resin particles 5 of samples A to C including crushed balls
2, the separation column 6 for backwashing was packed, and pure water 7 from the pure water tank 8 was injected from the bottom of the column 6 by the backwashing water pump 9 to sufficiently spread the resin particles 5 on the upper side. Then, after quiescence, the crushed resin particles collected above the column 6 were removed by the siphon 11. Removal of the crushed resin particles was carried out by backwashing a plurality of times, and a small amount was removed each time. The total amount of the crushed resin particles extracted was previously determined based on the measured sphericity data. In FIG. 2, 10 is a flow meter and 12 is a waste resin particle receiver. Test condition No. 10
Shown in the table.

[0033]

[Table 10]

Test Results The results of backwash separation under the above test conditions are summarized in Table 11 below.

[0035]

[Table 11]

As shown in the above Table 11, the sphericity was 99% or more, which was extremely good. Although it is possible to further increase the sphericity by reducing the amount of resin recovered from the current level, the conventional sphericity measurement methods are all 100%. Can be said to be a high level far exceeding the level of general-purpose resins. As a further method of separating crushed balls, a water sieving method using a rectangular opening screen will be described.

D. Water sieving method and test method using a rectangular opening screen 40 ml of resin of sample D containing crushed balls is put into a rectangular opening screen together with pure water, and pure water is added from above, and the screen is shaken vertically and horizontally. Meanwhile, the crushed resin particles are discharged to the crushed resin particle receiver below the screen. The resin particles on the upper part of the screen were collected and the sphericity was measured. The test conditions are shown in Table 12.

[0038]

[Table 12]

Test results The results of sieving under the above test conditions are shown in the following first
It is summarized in 3 tables.

[0040]

[Table 13]

As shown in the above Table 13, the sphericity is 99% or more, which is extremely good. Moreover, the recovery rate of the resin particles is better than that of the backwash separation method. In the conventional measuring method of the sphericity, since all are 100%, it can be said that the current achieved level is a high level far exceeding the level of general-purpose resin particles.

4. Confirmation of Resin Soundness Using sound resin samples A and D manufactured by the first process and the second process, the soundness of the resin was evaluated as follows.

Evaluation Test Method Samples A and D of sound resin particles secured by the pump circulation method used for the crushing test in the first process were circulated in the resin slurry circulation device shown in FIG.
The sphericity was measured. The resin particles 2 were transferred together with water into a beaker 1 having a capacity of 500 ml, the slurry was circulated through a circulation circuit formed by the magnetic pump 3 and the silicone rubber tube 4, and the resin particles were sampled after the circulation operation was completed. Measure the ratio of crack spheres and crushed resin. The test conditions are shown in Table 14.

[0044]

[Table 14]

Test results: A pump circulation operation was carried out for 60 minutes on samples A and D, and after the operation was completed, resin particles were sampled and cracked balls,
The results of measuring the ratio of crushed balls and healthy spheres are given in Section 15 below.
Shown in the table.

[0046]

[Table 15]

As a result of the test, the sphericity was extremely good at 99% or more, and the sound spheres purified in the first and second processes described above were newly crushed even in the abrasion resistance test by pump circulation. It was confirmed that it will not be done. Although the proportion of crushed spheres slightly increased, it is presumed that these were due to the fact that the crushed spheres and crack spheres that originally existed were partially crushed again.

[0048]

As described in detail above, according to the present invention, the following excellent effects are expected. (1) Conventionally, the ion exchange resin particles used in the BWR condensate desalination apparatus have not been subjected to the crushing and removing treatments of the cracked spheres and the crushed spheres as in the present invention, and the resin particles are put into the plant. Due to the load applied to the resin particles at the time of filling, some of the cracked resin particles are crushed, and the crushed particles generated at the time of manufacturing remain, so that these crushed resin particles and their crushed parts are in operation. In addition, it may pass through the screen from the condensate demineralizer, flow out to the downstream, enter the reactor and be decomposed, resulting in deterioration of water quality. When ion-exchange resin particles treated by the present invention to remove cracked resin particles and crushed resin particles were used in a BWR plant, the conductivity of the reactor water was 0.1 μS before the ion-exchange resin exchange.
/ Cm, the value decreased to 0.07 μS / cm or less, which is favorable. Further, the sulfate ion concentration in the reactor water also decreased to 1 ppb or less compared to the value before the ion exchange resin exchange, 4 ppb, and is in good condition. By applying the present invention in this way, it is possible to achieve a dramatic improvement in the quality of treated water in the desalination apparatus.

(2) By periodically applying the present invention to ion-exchange resin particles for a desalting apparatus, cracked spheres and crushed spheres can be efficiently removed, and high purity of treated water can be maintained during operation. Is possible. (3) By applying the present invention to an ion exchange resin used in a desalting apparatus for a long period of time, crack spheres and crushed spheres present in resin particles can be efficiently removed, Only healthy spheres can be secured. By filling the desalting device with the resin particles, it becomes possible to maintain good water quality.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a resin slurry circulation device that performs a pump circulation method of a first process.

FIG. 2 is a schematic explanatory view of a device for separating crushed resin particles by a backwash separation method.

[Explanation of symbols]

1 500ml beaker 2 resin particles 3 Magnetic pump 4 Silicone rubber tube 5 ion exchange resin 6 Backwash separation column 7 Pure water 8 Pure water tank 9 Backwash water pump 10 Flowmeter 11 siphon 12 Waste resin particle receiver

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B02C 19/18 B02C 19/18 E Z 23/08 23/08 Z B03B 5/00 B03B 5/00 Z B07B 1/28 B07B 1/28 ZF term (reference) 4D021 CA07 EA10 4D025 AA03 AB19 BA08 BA14 BB02 4D067 CE02 CG09 EE11 EE18 GA16 4D071 AA05 DA20

Claims (5)

[Claims] 1. The cation-exchange resin particles and / or anion-exchange resin particles used in a desalting apparatus are subjected to a physical and / or chemical crushing action on the resin particles before being subjected to a water sampling operation. To crush only the resin particles having latent defects such as internal strain and fine cracks, and the second process to remove the resin particles crushed in the first process from the sound resin particles. A method for improving water quality in a desalination apparatus, which comprises filling a desalination apparatus with sound resin particles not containing resin particles having a physical defect and performing a water sampling operation. 2. In the first process, the ion-exchange resin particles to be used are contained in a container filled with water, and circulation operation by a pump, agitation by a stirrer, or ultrasonic wave transmission is intermittent or continuous. The means for carrying out the above, a means for injecting water after heating the ion exchange resin to such an extent that functional groups are not decomposed by a dryer, or a resin having a relatively high concentration of regenerants such as hydrochloric acid, sulfuric acid, nitric acid, caustic soda, and salt Either means or a combination of means for sufficiently washing with pure water after soaking in chemicals, and the second process is scrubbing the crushed resin with air or nitrogen gas and then developing rate is 100% or more for 30 minutes or more. A backwashing and overflow removing means, or a means for sieving a resin in a dry state or crushed with water with a vibrating screen or the like, A method for improving water quality of a desalination apparatus according to claim 1. 3. The respective means of the first process can be linked to the operation of the desalination device by being incorporated in the operation operation of the desalination device in advance, and can be automatically operated by using a sequencer, a program timer or the like. The method for improving water quality of a desalination device according to claim 1, wherein 4. Not only new ion-exchange resin particles, but also used in a desalting device for a long time and applied to ion-exchange resin particles with reduced physical strength to ensure only healthy resin particles without potential defects and to remove them. The method for improving water quality of a desalination device according to claim 1, wherein the water quality is improved by filling the salt device and performing a water sampling operation so as to eliminate generation of fine resin and crushed resin during extended life. 5. Only resin particles having latent defects such as internal strain and fine cracks by physically and / or chemically crushing the cation exchange resin particles and / or the anion exchange resin particles. Is characterized by filling healthy resin particles not containing resin particles having a latent defect by a first process of crushing resin particles and a second process of removing resin particles crushed in the first process from healthy resin particles. Desalination equipment.