JP2004113951A - Method and apparatus for separating ion-exchange resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for separating an ion-exchange resin, whereby, in separating an ion-exchange resin containing suspended matters in a separation tower, the interface between an anion-exchange resin layer and a cation-exchange resin layer is correctly detected by excluding the influence of the suspended matters. <P>SOLUTION: An ion-exchange resin comprising an anion-exchange resin and a cation-exchange resin is put into a separation tower and separated into an anion-exchange resin layer and a cation-exchange resin layer by supplying back washing water to the separation tower. Before putting the ion-exchange resin into the tower, water is put into the tower in such an amount that the water level becomes higher than the position of a sensor part, which is installed in the tower for optically detecting the interface between the anion-exchange resin layer and the cation-exchange resin layer. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and apparatus for separating an ion exchange resin suitable for separating an ion exchange resin filled in a separation tower into an anion exchange resin layer and a cation exchange resin layer.
[0002]
[Prior art]
When condensed water is collected and reused, it is necessary to remove suspended or soluble substances contained in the condensed water. For such condensate treatment, for example, a desalination tower filled with a mixed resin (ion exchange resin) of a cation exchange resin and an anion exchange resin is often used. The ion exchange resin filled in the desalination tower needs a regeneration treatment with a cycle of several days to about one week.
[0003]
In order to regenerate this mixed resin, it is necessary to separate it into a cation exchange resin and an anion exchange resin in advance. In this case, it is important to grasp the interface between the anion exchange resin layer and the cation exchange resin layer separated in the separation tower. Therefore, the inventors have previously proposed a method and a detection means for detecting an interface of an ion exchange resin using a color difference (gradation difference) between an anion exchange resin and a cation exchange resin (see Patent Document 1).
[0004]
In this interface detection method, first, pixel data obtained by an imaging unit provided on a side wall surface of a separation tower is decomposed for each pixel, and compared with reference gradation data of an ion exchange resin. Next, gradation difference data of the ion exchange resin is generated for each pixel. Then, the ratio of these gradation difference data to the total pixels is determined to determine the position of the boundary surface between the anion exchange resin layer and the cation exchange resin layer.
[0005]
Alternatively, there is a method of determining an interface based on a difference in color of an ion exchange resin (see Patent Document 2). This is based on the fact that the anion exchange resin is yellow or white and the cation exchange resin is brown or red, and the interface is determined based on the color difference. The invention disclosed in Patent Literature 2 projects light onto an ion-exchange resin layer, receives the reflected light with an interface detector including a color determination sensor, and detects a boundary surface according to the amount of reflected light. It is comprised in.
[0006]
[Patent Document 1]
Japanese Patent Application No. 2002-266646 [Patent Document 2]
Japanese Patent No. 2621575 [0007]
[Problems to be solved by the invention]
In these methods for detecting the interface of the ion-exchange resin layer, the inside of the separation tower is detected by an optical sensor (for example, an image sensor or a color discrimination sensor) through an observation window (viewing window) provided on the wall of the separation tower. The interface of the ion exchange resin layer is determined based on the detection data. Incidentally, the observation window is configured to be bolted and fixed to the side surface of the separation tower together with, for example, a frame holding a translucent window glass.
[0008]
In the regeneration treatment of the ion exchange resin, after the treatment is completed, the separation tower is stored with the inside thereof being empty. Then, when performing the regeneration treatment of the ion exchange resin filled in the desalination tower, the ion exchange resin is transferred to the separation tower together with the washing water. At this time, the ion exchange resin is fed from the bottom of the separation tower, and the water level of the washing water gradually rises. Then, as the liquid level rises, the liquid level passes through an observation window (viewing window) provided on the wall surface of the separation tower.
[0009]
At this time, a phenomenon occurs in which suspended matter near the liquid surface adheres to the observation window. Therefore, when separating the ion-exchange resin in the separation tower, the suspended matter attached to the observation window hinders the visual field inside the separation tower, so that the interface of the ion-exchange resin layer cannot be detected by the optical sensor. there were.
Also, if dirt adheres to the viewing window, it cannot be completely cleaned only by backwashing water in the separation tower, and the viewing window must be manually cleaned before performing the next separation process. There were also problems.
[0010]
Alternatively, even when the interface of the ion exchange resin layer is detected by an optical sensor incorporated inside the separation tower, the suspended substance adheres to the optical sensor for the above-described reason. For this reason, there was a problem that the interface of the fat layer could not be detected.
The present invention has been made in consideration of such circumstances, and its purpose is to eliminate the influence of the suspended substance when separating the ion-exchange resin containing the suspended substance in the separation column. It is an object of the present invention to provide a method and an apparatus for separating an ion exchange resin, which can correctly detect an interface between the anion exchange resin layer and the cation exchange resin layer.
[0011]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, a method for separating an ion-exchange resin according to claim 1 fills a separation tower with an ion-exchange resin containing an anion exchange resin and a cation exchange resin, and supplies backwash water to the separation tower. When separating into an anion exchange resin layer and a cation exchange resin layer and then, before filling the separation tower with the ion exchange resin, the anion exchange resin layer and the cation exchange resin layer provided in the separation tower It is characterized in that the separation tower is previously filled with water up to a position above the sensor section for optically detecting the interface.
[0012]
The sensor unit used for the method for separating the ion exchange resin is constituted by a viewing window provided on a wall surface of the separation tower, or an optical sensor incorporated inside the separation tower to image the inside of the separation tower. Further, the height of the liquid level of the water previously filled in the separation tower is set by adjusting the amount of backwash water supplied to the separation tower.
For this reason, the height of the liquid level of the water in the separation tower is located above the sensor section, and the suspended solids floating on the liquid level do not adhere to the viewing window or the optical sensor. .
[0013]
According to the method for separating an ion exchange resin according to the fourth aspect, a separation tower filled with an ion exchange resin containing an anion exchange resin and a cation exchange resin, and backwash water is supplied to the separation tower. Backwash water supply means for separating the ion exchange resin into an anion exchange resin layer and a cation exchange resin layer, and the anion exchange resin layer provided in the separation tower and viewing the inside of the separation tower from the side. A sensor unit for optically detecting the interface with the cation exchange resin layer, and permitting the separation tower to be filled with the ion exchange resin when the separation tower is filled with water up to above the sensor unit. And a filling control unit that performs the charging.
[0014]
This sensor section is constituted by a viewing window provided on the wall surface of the separation tower or an optical sensor incorporated inside the separation tower to image the inside of the separation tower.
Therefore, according to the present invention, even when the ion exchange resin in which the anion exchange resin and the cation exchange resin containing a large amount of the suspended substance are mixed is to be separated, the interface thereof can be optically detected. A method and apparatus for separating an ion exchange resin can be provided.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a method and an apparatus for separating an ion exchange resin according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an example of a condensate desalination device for a power plant using the ion exchange resin separation device according to the present invention. This condensate desalination apparatus includes a desalination tower 10 for removing salt (seawater) contained in condensate. The desalting tower 10 is filled with an ion exchange resin 1 for removing salt contained in the condensate. This ion exchange resin 1 is made of a mixed resin of an anion exchange resin and a cation exchange resin. In addition, a strainer 11 is connected to the lower part of the desalination tower 10 for removing impurities such as corrosion products generated from the plant constituent materials from the condensed water subjected to the desalination treatment in the desalination tower 10.
[0016]
In such a desalting tower 10 in which an anion exchange resin and a cation exchange resin are mixed, it is necessary to periodically regenerate the ion exchange resin 1. For this reason, a separation tower 20 for separating the cation exchange resin and the anion exchange resin filled in the desalting tower 10 is connected to the desalting tower 10.
A water supply pipe 22 having a flow control valve 21 is connected to a lower portion of the separation tower 20. Then, by adjusting the flow rate of the backwash water supplied into the separation tower 20 by the flow control valve 21, these exchange resins are separated into two layers by utilizing the specific gravity difference between the cation exchange resin and the anion exchange resin. You.
[0017]
Specifically, the anion exchange resin and the cation exchange resin flow in the separation tower 20 by supplying the backwash water. Then, the anion exchange resin having a small specific gravity is separated as an anion exchange resin layer 2 at the upper part of the separation tower 20, while the cation exchange resin having a large specific gravity is separated as a cation exchange resin layer 3 at a lower part of the separation tower 20. At a substantially central portion of the separation tower 20, a collector 23 is provided which takes out an anion exchange resin having a low specific gravity from the exchange resins separated into two layers and transfers the resin to the anion exchange resin regeneration tower 40.
[0018]
Further, on the side wall surface of the separation tower 20, an observation window 24 (viewing window) for observing the state inside the separation tower 20 is provided corresponding to the height position where the collector 23 is arranged (FIG. 2). . This observation window 24 allows the state of separation (boundary surface) of the ion exchange resin to be observed from the outside. The observation window 24 is provided with an optical sensor 25 for observing the state of separation of the ion exchange resin 1 through the observation window 24.
[0019]
The optical sensor 25 is attached to the observation window 24 so that the peripheral portion of the collector 23 arranged in the separation tower 20 is set as an imaging range, and the collector 23 is viewed substantially in the center of the imaging range. As the optical sensor 25, for example, a CCD camera or a CMOS sensor is used. Then, data captured by the optical sensor 25 is sent to the interface detection device 30. The interface detection device 30 separates the ion exchange resin by adjusting the flow control valve 21 based on the imaged data.
[0020]
The feature of the present invention in the ion exchange resin separation apparatus thus configured is that, before the separation tower 20 is filled with the ion exchange resin, the interface between the anion exchange resin layer 2 and the cation exchange resin layer 3 is increased. Is that the separation tower 20 is previously filled with washing water up to a position above the visual field range of the optical sensor 25 that optically detects the water.
[0021]
More specifically, a method for separating an ion exchange resin in the condensate deionization apparatus according to the present invention will be described in detail with reference to a flowchart shown in FIG.
First, water washing is performed in the desalting tower 10 to remove impurities contained in the ion exchange resin in which the anion exchange resin and the cation exchange resin are mixed (Step S1). Next, the interface detection device 30 opens the flow control valve 21 provided at the lower part of the separation tower, and injects backwash water into the separation tower 20 (Step S2). The backwash water is injected by the interface detection device 30 until the water surface is above an observation window (viewing window) 24 attached to the separation tower 20 (step S3). Specifically, the interface detection device 30 opens the flow control valve 21 and injects the backwash water into the separation tower 20 so that the water surface of the backwash water is positioned above the visual field range of the optical sensor 25 attached to the observation window 24. .
[0022]
Then, when the backwash water is injected until the water surface is above the observation window 24, the ion exchange resin in the desalination tower 10 is transferred to the separation tower 20 (Step S4). Next, in order to separate the ion exchange resin 1 transferred to the separation tower 20 into the anion exchange resin layer 2 and the cation exchange resin tank 3, the interface detection device 30 is provided with a flow control valve 21 provided below the separation tower 20. Is opened, and backwash water is injected (step S5). Then, the ion exchange resin 1 is separated into two layers of the anion exchange resin layer 2 and the cation exchange resin layer 3 by the flow rate of the backwash water (step S6).
[0023]
Of the ion exchange resins thus separated, only the anion exchange resin is taken out via the collector 23 and transferred to the anion exchange resin regeneration tower 40 (Step S7). Then, since only the cation exchange resin remains in the separation tower 20, a chemical solution is injected into the separation tower 20 and the anion exchange resin regeneration tower 40 to perform a regeneration treatment (step S8).
[0024]
When the regeneration process is completed, the washing water is injected into the separation tower 20 and the anion exchange resin regeneration tower 40 to remove the chemical used for the regeneration (step S9). The cation exchange resin and the anion exchange resin that have undergone such a series of regeneration treatments are transferred to and stored in the resin storage tank 50 (Step S10).
Then, the ion-exchange resin stored in the resin storage tank 50 is transferred to the desalination tower 10 as needed and reused (Step S11).
[0025]
Thus, according to the ion exchange resin separation method described above, prior to filling the ion exchange resin into the separation tower 20, the position above the visual field of the optical sensor 25 provided in the separation tower 20 in steps S2 and S3. Until the backwashing water is filled in the separation tower 20 in advance, the suspended matter adhering to or mixed with the ion exchange resin does not adhere to the field of view of the optical sensor 25 attached to the observation window 24.
[0026]
Further, since the suspended substance does not adhere to the visual field range of the optical sensor 25 attached to the observation window 24, the cleaning work of the observation window 24 which has been performed before and after the separation process of the ion exchange resin is not required. Furthermore, since there is no suspended substance adhering to the observation window 24 when the ion exchange resin is transferred, it is possible to detect the interface of the ion exchange resin layer with high accuracy.
Especially when the power plant is started, the condensate contains a lot of iron components (rust, etc.). For this reason, the iron-exchange resin subjected to the desalination treatment of the condensed water at the start of the power plant contains a large amount of this iron component. In a conventional ion-exchange resin separation apparatus, when the ion-exchange resin containing a large amount of the iron component is injected into the separation tower 20, the iron component adheres to the observation window 24. Was a factor that hindered the detection of In addition, since the iron component attached to the observation window 24 is similar to the color (brown or red) of the cation exchange resin, it also causes erroneous detection of the interface.
[0027]
On the other hand, according to the ion exchange resin separation method of the present invention, before filling the ion exchange resin into the separation tower 20, the visual field range of the optical sensor 25 provided in the separation tower 20 in steps S2 and S3 is increased. Since the separation tower 20 is previously filled with backwash water up to the upper position, it is possible to prevent the iron component from adhering to the observation window 24. Therefore, it is extremely effective in separating an ion exchange resin containing a large amount of suspended substances.
[0028]
In the above-described embodiment, the suspended substance adhering to or mixed with the ion exchange resin is prevented from adhering to the observation window 24 provided on the side surface of the separation tower 20. Although not shown, an optical sensor may be incorporated inside the separation tower 20 to detect the boundary surface of the ion-exchange resin without using the intermediary of the separation tower 24. In this case, if water is injected into the separation tower 20 prior to the separation of the ion exchange resin, and the washing water is injected above the visual field range of the optical sensor, it is possible to prevent suspended substances from adhering to the optical sensor. it can. For this reason, it is possible to detect the interface of the ion exchange resin layer with high accuracy.
[0029]
In the above-described embodiment, water is injected into the separation tower 20 before transferring the ion-exchange resin to the separation tower 20. Even if the cleaning water is injected, the same effect can be obtained because the observation window 24 is previously filled with the backwashing water.
As described above, the present invention can be variously modified and implemented without departing from the gist of the present invention without being limited to the above-described embodiment.
[0030]
【The invention's effect】
As described above, according to the method and apparatus for separating an ion exchange resin of the present invention, an observation window or a separation tower in which a suspended substance adhered to or mixed with the ion exchange resin detects an interface of the ion exchange resin layer. It does not adhere to the optical sensor incorporated inside the camera. For this reason, when separating the ion exchange resin, it is possible to detect the interface of the ion exchange resin layer while maintaining high accuracy. Further, it is not necessary to clean the observation window or the optical sensor every time the image is regenerated, so that maintenance can be improved.
[0031]
In particular, it has a great practical effect such as being effective for the separation and regeneration treatment of an ion exchange resin containing a large amount of suspended substances.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an ion exchange resin separation device according to an embodiment of the present invention.
FIG. 2 is a diagram showing a main part of an ion exchange resin separation device according to one embodiment of the present invention.
FIG. 3 is a flowchart showing a method for separating an ion exchange resin according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Demineralization tower 20 Separation tower 21 Flow control valve 22 Water supply pipe 23 Collector 24 Observation window 25 Optical sensor 30 Interface detection device 40 Anion exchange resin regeneration tower 50 Resin storage tank

Claims (5)

Filling a separation tower with an ion exchange resin containing an anion exchange resin and a cation exchange resin, upon supplying backwash water to the separation tower to separate the anion exchange resin layer and the cation exchange resin layer,
Prior to filling the separation tower with the ion exchange resin, before the sensor section for optically detecting the interface between the anion exchange resin layer and the cation exchange resin layer provided in the separation tower, A method for separating an ion exchange resin, wherein the separation tower is filled with water. The method for separating an ion-exchange resin according to claim 1, wherein the sensor unit comprises a viewing window provided on a wall surface of the separation tower, or an optical sensor incorporated inside the separation tower to image the inside of the separation tower. . The method for separating an ion-exchange resin according to claim 1, wherein the liquid level of the pre-filled water in the separation tower is set by adjusting the amount of backwash water supplied to the separation tower. . A separation tower filled with an ion exchange resin containing an anion exchange resin and a cation exchange resin,
Backwash water supply means for supplying backwash water to the separation tower to separate the ion exchange resin into an anion exchange resin layer and a cation exchange resin layer,
A sensor unit provided in the separation tower for optically detecting an interface between the anion exchange resin layer and the cation exchange resin layer while viewing the inside of the separation tower from the side thereof,
A filling control means for permitting the filling of the ion-exchange resin into the separation tower when the separation tower is filled with water up to above the sensor unit. . 5. The ion exchange resin separation device according to claim 4, wherein the sensor unit comprises a viewing window provided on a wall surface of the separation tower, or an optical sensor incorporated inside the separation tower to image the inside of the separation tower. .

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