JPH0568973A - Partial resin regeneration type condensed water desalting apparatus - Google Patents

Abstract

PURPOSE:To regenerate only the resin of the upper part of a mixed resin tank by drawing out only the upper part of the mixed resin of the tank in the title apparatus wherein a container main body having a raw solution inlet and a treated solution outlet and a resin tank wherein a cation resin and an anion resin are mixed in a container are provided. CONSTITUTION:A condensed water desalting apparatus for treating the condensed water from the condenser of an atomic power plant has a desalting tower 1 to which condensed water is guided through a pipe 21 and an inlet valve 22 and condensed water is subjected to desalting treatment by a mixed resin 10 of a cation resin and an anion resin to be sent to a downstream system through an outlet valve 23 and a pipe 24. When the whole quantity of the resin is regenerated, the respective resins are regenerated in a cation regeneration tower 2 and an anion regeneration tower 3 to be returned to the desalting tower 1 through a resin storage tank 4. In this case, the taking-out system 42 of the intermediate part resin of the bed-shape mixed resin 10 of the desalting tower 1 and a resin pushing water system 54 are provided and an anion resin taking-out system 44 after partial resin separation is provided to the cation regeneration tower 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desalting apparatus in which a cation resin and an anion resin are mixed in a container for desalting a stock solution, and in particular, it is possible to extract only the upper part of a mixed resin layer. It also relates to a demineralization tower and resin regeneration equipment that can regenerate even a partial amount of resin smaller than the specified amount of resin held in the container.

[0002]

2. Description of the Related Art For example, a condensate demineralizer is an apparatus installed to remove suspended solids and dissolved solids in condensate in thermal power and nuclear power plants.

FIG. 3 shows a schematic system of a nuclear power plant. The steam generated in the nuclear reactor 61 is supplied to the turbine 62, then condensed in the condenser 63, pressurized by the condensate pump 64, filtered and desalted by the condensate filter 65 and the condensate demineralizer 66. , Condensate booster pump 67, low pressure feed water heater 68,
The reactor 61 through the feed water pump 69 and the high pressure feed water heater 70.
To be steamed again. Here, seawater is used to cool the condenser 63.

FIG. 4 shows a schematic system of a conventional condensate desalination apparatus. Condensate as undiluted solution is pipe 21, inlet valve 2
It is guided to the desalting tower 1 by 2 and desalted by the layered mixed resin 10 of the cation resin and the anion resin. Condensate that has been desalted with the layered mixed resin 10 is discharged from the outlet valve 23 and the pipe 24.
To the downstream system. The resin that has captured the suspended solids and dissolved solids in condensate after desalting for a certain period of time is
It is transferred to a recycling facility for recycling, and the resin is backwashed and recycled. That is, the mixed resin 10 in the demineralization tower 1 includes the resin outlet valve 30, the resin transfer pipe 31, and the cation regeneration tower inlet valve 3.
It is transferred to the cation regeneration tower 2 via 2. At this time, the water inlet valve 25 and the air inlet valve 2 for mixing and transferring the resin.
6, water and air are supplied from the pipe 27, and the whole amount of the mixed resin 10 in the desalting tower 1 is transferred to the cation regeneration tower 2 while scrubbing. The resin transferred to the cation regeneration tower 2 is pipe 4
5. After mixing with the air supplied from the valve 46 and water, the specific gravity is separated into the anion resin 11 in the upper layer and the cation resin 12 in the lower layer. After separation, the anion resin 11 is transferred to the anion regeneration tower 3 through the valve 35 and the pipe 36,
4, is regenerated by caustic soda supplied from the valve 55 and the medicine distributor 56. Also, cationic resin 1
In the cation regeneration tower 2, 2 is regenerated by the sulfuric acid supplied from the pipe 51, the valve 52, and the pass distributor 53. The regenerated cation resin 12 is transferred to the resin storage tank 4 via the valve 33 and the pipe 34, and the anion resin 11 is transferred to the resin storage tank 4 via the valve 37 and the pipe 38. After washing, water and air supplied from the pipe 49 and the valve 50. Is mixed by the valve 39, the pipe 40, and the resin inlet valve 41, and is returned to the desalting tower 1 to be subjected to desalting treatment.

Here, a condenser 6 is included in the condensate that is the undiluted solution.
Seawater may be mixed in due to the seawater leak in item 3 above. The seawater mixed in the condensate causes corrosion of the equipment in the plant, so desalting is performed by the condensate demineralizer 66. FIG. 5 shows the relationship between the bed height of the mixed resin 10 loaded in the desalting tower 1 and the sodium concentration captured by the resin. As shown in FIG. 5, sodium in the resin is not trapped on average in the entire resin layer, but sequentially from the upper layer portion,
Tends to be captured. Further, FIG. 6 shows the relationship between the number of times of regeneration and the ion exchange capacity of the resin. As shown in FIG. 6, the ion exchange capacity tends to decrease as the number of times of regeneration increases.

[0006] The condenser 62 is not continuously operated for a long period in a state where the seawater leaks, and normally, repair treatment is performed at an arbitrary time after the seawater leak occurs. In this case, the trapping of sodium with the mixed resin 10 is performed only in the upper part of the resin layer, and the sodium concentration in the lower layer is in a low state. However, the desalination treatment of condensate in a state where sodium is retained, the sodium may leak into the treated water, so that the regeneration is performed as much as possible. Also,
When the suspended solid matter trapped by the layered mixed resin 10 is washed only by backwashing and reused, the sodium trapping resin is diffused throughout the desalting tower, and in this case also, sodium leaks into the treated water. There was a problem.

FIG. 7 shows a case where a cationic resin 13 is loaded on top of the mixed resin 10 in the desalting tower 1 instead of the condensate filtering device. In this case as well, only the cationic resin 13 is used alone as a regenerating facility. Although the mixed resin 10 can be transferred, the entire amount of the mixed resin 10 is transferred, and the cationic resin 12 obtained by separating the mixed resin 10 and the cationic resin 13 for capturing suspended solids can be individually transferred, but a partial volume of the resin can be transferred. There was no function to play.

A device related to this type of device is, for example, Japanese Patent Application Laid-Open No. 55-59881.

[0009]

In the above-mentioned prior art, since the total amount of the mixed resin in the desalting tower is regenerated, the resin above the resin layer captures suspended solids and dissolved solids, and the lower resin It is necessary to regenerate the entire amount of resin even if the trapping ability of the resin remains, and partial resin regeneration of only the upper layer of the resin could not be performed.Therefore, backwashing of the resin causes diffusion of ion trapping resin such as sodium in the desalting tower. It was not possible to prevent the leakage of ions due to the above, and to prevent the reduction of the ion exchange capacity due to the reduction of the number of regeneration.

According to the present invention, a resin take-out line is provided in the middle portion of the mixed resin layer of the desalting tower, and the cation regeneration tower is provided with a function of regenerating the partial resin, so that only the resin above the mixed resin layer is regenerated. Made possible.

[0011]

In order to achieve the above-mentioned object, the present invention provides a nozzle for removing partial resin, a pipe and a valve in the middle portion of a mixed resin layer of a desalting tower, and installs them above the resin removing nozzle. A resin pushing water nozzle, pipes, and valves were installed to take out the resin uniformly.

Further, the cation regenerator is provided with an anion resin take-out nozzle, a pipe and a valve so that even a partial volume of resin can be regenerated.

[0013]

[Function] The nozzle for taking out the partial resin has a role of extracting the resin on the upper part of the mixed resin layer nozzle from the desalting tower, and the resin pushing water nozzle has a function of uniformly extracting the resin on the upper part of the mixed resin layer nozzle. Not only does it act as transfer water to prevent resin clogging of the piping.

Further, the anion resin take-out nozzle of the cation regeneration tower acts as an extraction nozzle for transferring the anion resin to the anion regeneration tower after separating a small amount of resin.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The function of introducing the stock solution from the upper part of the desalting tower 1 and removing the suspended solids and the dissolved solids with the layered mixed resin 10 remains unchanged.

FIG. 1 shows a system of a condensate demineralizer for partial resin regeneration.

That is, the condensate demineralizer 66 shown in FIG.
Treats the condensed water condensed in the condenser 63. This condensate is guided to the desalination tower 1 via the pipe 21 and the inlet valve 22 shown in FIG. The condensate introduced into the desalting tower 1 is desalted by the mixed resin 10 and sent to the downstream system through the outlet valve 23 and the pipe 24. When regenerating the entire amount of the resin, it is sent from the desalting tower 1 to the cation regenerating tower 2 via the resin outlet valve 30, the pipe 31 and the valve 32. In the cation regeneration tower 2, the resin is separated,
The anion resin 11 is transferred to the anion regeneration tower 3 and regenerated with caustic soda, and the cation resin 12 is cation regeneration tower 2
Is regenerated with sulfuric acid. The regenerated resins are transferred to the resin storage tank 4, washed and mixed, and then transferred to the desalting tower 1 and again subjected to desalting treatment.

Here, the point different from the conventional one is that a resin take-out system is provided at an intermediate portion of the layered mixed resin 10 of the desalting tower 1.
This is because a resin pushing water system was provided, and a cation regeneration tower was provided with an anion resin removing system after partial resin separation.

The demineralizer resin traps suspended and dissolved solids in the condensate. For example, in the case of seawater leak, sodium and chlorine contained in seawater are captured by the layered mixed resin 10, but sodium is sequentially captured from the upper portion of the resin layer as shown in FIG. The seawater leak of the condenser 63 is not normally operated as it is, and the plant output is lowered to repair the seawater leak by observing the operating state, thereby eliminating the mixture of seawater into the condensate. From seawater leak in condenser 63 to repair of condenser 63,
Sodium in seawater is captured by the condensate desalination device 66. Here, the sodium trapped by the mixed resin 10 of the desalting tower 1 has a problem that when the ionic substance is operated in a trapping state, the resin ion-exchanges with other ionic substances to expel sodium and leak from the desalting tower. Therefore, it is necessary to regenerate the resin. As shown in FIG. 6, the resin also tends to have a reduced ion exchange capacity as the number of regenerations increases.
The number of reproductions should be as small as possible.

Conventionally, this is a system in which the entire amount of the resin is extracted, and when the ion exchange capacity decreases due to the capture of the dissolved solids, the resin in that portion could not be regenerated.

A valve 41, is provided in the middle portion of the mixed resin 10 of the desalting tower 1.
The pipe 42, the pipe for pushing water 57, and the valve 58 are provided. When sodium or the like is desalted by the mixed resin 10 of the desalting tower 1, a resin pushing water pipe 5 provided beside the desalting tower 1
7, water is supplied from the valve 58, the valves 41 and 32 are opened, and the water is transferred to the cation regeneration tower 2 via the pipe 31. A part of the mixed resin 10 transferred to the cation regeneration tower 2 is scrubbed with water and air supplied from a pipe 45 and a valve 46, and then separated by specific gravity to become an anion resin 14 in an upper layer and a cation resin 15 in a lower layer. .. The anion resin 14 is sent to the anion regeneration tower 3 through a newly provided valve 43 and anion resin transfer pipe 44 to be regenerated. Here, caustic soda and sulfuric acid used to regenerate the resin need only be passed through the required amount with respect to the amount of resin, so a chemical passant distributor (sulfate distributor 53,
It can be shared with caustic soda distributor 56). The resin regenerated in each regeneration tower is transferred to the resin storage tank 4, washed and mixed, and returned to the desalting tower 1. The resin returned to the desalting tower 1 is piled up on top of the mixed resin remaining in the desalting tower 1, and is subjected to desalting treatment as the mixed resin 10.

Further, when the differential pressure increases due to the trapping of suspended solids in the desalting tower, the suspended solids are trapped in the upper layer of the resin. Therefore, only the upper layer of the mixed resin 10 is transferred to the cation regeneration tower 2. Then, backwashing / washing is performed and the pressure is returned to the desalting tower 1 to recover the differential pressure. In a non-regeneration operation plant in which the chemical regeneration of the resin is not carried out, such as in a nuclear power plant, the ion trapping resin such as sodium in the upper layer does not mix with the resin in the lower layer of the desalting tower 1, which also prevents leakage of trapped ions.

In FIG. 2, the regeneration tower structure adopted in the nuclear power plant is a cation regeneration tower 2 and an anion regeneration tower 3.
The case of a tower configuration is shown. Also in this case, the basic partial resin regeneration is the same, and the difference from FIG. 1 is that the anion resin regenerated in the anion regeneration tower is returned to the cation regeneration tower 2, washed and mixed, and then transferred to the desalting tower.

According to the present embodiment, a nozzle for extracting the partially mixed resin, a pipe and a valve are provided in the middle of the layered mixed resin 10 of the desalting tower 1, a nozzle for pushing water, a pipe and a valve are provided, and By providing the anion resin transfer nozzle for the partial resin, the pipe and the valve in the cation regeneration tower 2 to enable the partial regeneration of the resin and backwashing and washing, it is possible to prevent the resin from diffusing in the desalting tower. This has the effects of preventing leakage of trapped ionic components and extending the life of the resin by reducing the number of times the resin is regenerated.

[0026]

According to the present invention, a system for extracting partially mixed resin is provided in the middle portion of the mixed resin layer of the desalting tower, a system for pushing water is provided, and an anion resin for partial resin is provided in the cation regeneration tower. By providing a transfer system to enable partial regeneration of resin and backwashing, it is possible to prevent the diffusion of resin in the desalting tower and prevent the leakage of ionic components captured by the resin, and to reduce the number of times the resin is regenerated. It has the effect of extending the service life.

[Brief description of drawings]

FIG. 1 is a system diagram of a partial resin regeneration type condensate desalination apparatus.

FIG. 2 is a system diagram of a partial resin regeneration type condensate desalination apparatus.

FIG. 3 is a system diagram of a nuclear power plant.

FIG. 4 is a system diagram of a conventional condensate desalination apparatus.

FIG. 5 is a resin layer sodium distribution map.

FIG. 6 is an explanatory view of the relationship between the number of times of resin regeneration and the ion exchange capacity.

FIG. 7 is a system diagram of a condensate desalination apparatus in which a cationic resin is loaded on the mixed resin layer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Desalination tower, 2 ... Cation regeneration tower, 3 ... Anion regeneration tower, 4 ... Resin storage tank, 10 ... Mixed resin, 11 Anion resin, 12 ... Cation resin, 21 ... Pipe, 22 ... Inlet valve, 2
3 ... Outlet valve, 24 ... Pipe, 30 ... Resin outlet valve, 31 ... Resin transfer pipe, 32 ... Cation regeneration tower resin inlet valve, 53, 54
… Outpatient distributor.

Claims (2)

[Claims] 1. A desalting apparatus having a container body having a stock solution inlet and a processing solution outlet and a resin layer in which a cation resin and an anion resin are mixed in the container, wherein only the upper part of the mixed resin layer can be extracted. The feature is a partially regenerated condensate demineralizer. 2. The partially regenerated condensate desalination apparatus according to claim 1, wherein a part of the extracted mixed resin can be regenerated in a regenerating facility.