JP2004098011A - Method for detecting interface of ion- exchange resin and interface detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for properly detecting an interface between an anion exchange resin and a cation exchange resin separated in a separation tower, and to provide an interface detection apparatus. <P>SOLUTION: The method comprises an imaging step for picking up the image of an ion-exchange resin layer in a predetermined region at a predetermined height position of the separation tower by imaging from the lateral side, a pixel determination step for determining a pixel signal corresponding to the ion-exchange resin by determining the pixel signal constituting the image obtained in the imaging step, a resin determination step for determining the type of the ion-exchange resin in the image from the number of the pixels of the pixel signal corresponding to the ion-exchange resin or from an area proportion dominated by the pixel signal in the predetermined region of the image, and an interface determination step for determining the interface of the ion-exchange resin layer within the imaging of the image in accordance with the determined resin layer. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for detecting an interface of an ion exchange resin suitable for detecting an interface between an anion exchange resin layer and a cation exchange resin layer separated in a separation tower.
[0002]
[Prior art]
When condensed water is collected and reused, it is necessary to remove suspended substances and soluble substances contained in the condensed water. For such a condensate treatment, for example, a desalting tower filled with a mixed resin (ion exchange resin) of a cation exchange resin and an anion exchange resin is used. The ion-exchange resin used by filling the desalination tower needs a regeneration treatment every several days to about one week. In this regeneration, the ion-exchange resin is exclusively transferred to the separation tower and backwashed with air and water. Then, after removing the products adhered to the ion exchange resin, the product is separated into two layers of a cation exchange resin layer and an anion exchange resin layer by utilizing a specific gravity difference of the ion exchange resin. Among the ion-exchange resins separated into two layers, an anion-exchange resin having a small specific gravity is taken out from a collector provided near the interface with the cation-exchange resin layer, and is transferred to the anion-exchange resin tower. Then, regeneration treatment is performed together with the cation exchange resin remaining in the separation tower.
[0003]
The anion exchange resin and the cation exchange resin subjected to the regeneration treatment are stored in a resin storage tank and returned to the desalting tower.
By the way, when separating and extracting the anion exchange resin layer and the cation exchange resin layer, it is important to grasp the boundary surface. As a method for detecting the boundary surface, a method utilizing a color difference (gradation difference) between the anion exchange resin and the cation exchange resin is known. For example, according to the method for detecting an interface of an ion exchange resin layer disclosed in Patent Document 1, pixel data obtained by imaging the inside of a separation tower is binarized based on a predetermined threshold, and this data is An average is obtained by adding pixels adjacent in the horizontal direction. The portion where the difference between the average values in the vertical direction is large is defined as the boundary between the anion exchange resin layer and the cation exchange resin layer.
[0004]
Alternatively, Patent Literature 2 discloses a method of determining a boundary surface based on a difference in color of an ion exchange resin. This is based on the fact that the anion exchange resin is yellow or white, while the cation exchange resin is brown or red, and the boundary surface 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.
[0005]
Alternatively, as another method of determining an object having a different color, for example, Patent Document 3 discloses a method using a color determination sensor. This is because, in addition to the R (red), G (green), and B (blue) values for each pixel of the captured color image, a difference value between the R value and the G value, a difference value between the B value and the G value, An image conversion apparatus calculates a difference value between an R value and a B value and extracts a color range based on the difference value corresponding to a selected color.
[0006]
[Patent Document 1]
JP 2000-288411 A [Patent Document 2]
Japanese Patent No. 2621575 [Patent Document 3]
JP 2001-202508 A
[Problems to be solved by the invention]
However, in the interface detection method using the binarizing means disclosed in Patent Document 1 described above, a conversion error may occur during the binarization process depending on the state of external light. For example, when only the cation exchange resin or the anion exchange resin is imaged in the separation tower, the binarization is performed by determining whether the resin is the cation exchange resin or the anion exchange resin based on a predetermined threshold value. In some cases, there is a problem that an error occurs in the determination of the type of the exchange resin and the data is erroneously recognized as data of a different ion exchange resin. In order to avoid this problem, the binarization threshold for determining the type of the ion exchange resin must be optimized each time so as to conform to the state of external light, and there is also a problem that workability is not good. .
[0008]
Further, in the method of determining a color based on a color image disclosed in Patent Document 2 or 3 described above, depending on the type of resin, the reflected light projected on the ion exchange resin may be weak. Alternatively, there has been a problem that the presence or absence thereof cannot be accurately determined.
The present invention has been made in view of such circumstances, and an object of the present invention is to detect an interface of an ion exchange resin that correctly detects an interface between an anion exchange resin layer and a cation exchange resin layer separated in a separation tower. A method and an interface detection device are provided.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, an anion exchange resin layer and a cation exchange resin layer separated by flowing backwash water through an ion exchange resin layer containing an anion exchange resin and a cation exchange resin filled in a separation tower. An interface detection method for detecting an interface, wherein an image of the ion-exchange resin layer filled in a separation tower is imaged from a side thereof and an image of the ion-exchange resin layer in a predetermined region at a predetermined height position in the separation tower. Is obtained (imaging step), and the type of ion exchange resin is determined from the pixel signals constituting the obtained image (pixel determination step).
[0010]
Next, a resin layer in the image is obtained from the determined number of pixels for each ion exchange resin or the area ratio of the pixel signal in a predetermined region of the image (resin determination step). Then, the interface between the anion exchange resin layer and the cation exchange resin layer in the imaging range of the image is determined according to the obtained resin layer (interface determination step).
[0011]
In the boundary surface determination step, a difference value between the pixel signal obtained in the pixel determination step and a reference pixel signal of the anion exchange resin and / or the cation exchange resin held in advance is calculated (difference data conversion step). Is calculated for each pixel row adjacent in the horizontal direction (average value calculation step).
Then, a difference value between the vertically adjacent pixel columns of the difference average value is calculated (difference calculation step). The position of the boundary between the anion exchange resin layer and the cation exchange resin layer is specified from the pixel region where the difference value is the maximum (interface position specifying step). Therefore, the interface between the anion exchange resin layer and the cation exchange resin layer in the separation tower can be correctly recognized.
[0012]
Further, the ion-exchange resin interface detection device of the present invention captures an image of an ion-exchange resin layer containing an anion-exchange resin and a cation-exchange resin filled in a separation tower from a side thereof and a predetermined height in the separation tower. Imaging means for obtaining an image of the ion-exchange resin layer in a predetermined region at the predetermined position, and determining whether or not the pixel signal corresponds to any of the ion-exchange resins from the pixel signals constituting the image obtained by the imaging means It is provided with pixel determination means.
[0013]
And a resin determination unit that calculates the ratio of the anion and cation exchange resin in the image from the number of pixels of the pixel signal corresponding to any one of the ion exchange resins or the area ratio occupied by the pixel signal in a predetermined region of the image, The image forming apparatus further includes a boundary surface determination unit that determines a boundary surface between the anion exchange resin layer and the cation exchange resin layer within the imaging range of the image according to the determined resin layer.
[0014]
The boundary surface determining means calculates a difference value between the pixel signal obtained by the pixel determining means and a reference pixel signal of an anion exchange resin and / or a cation exchange resin held in advance; Average value calculating means for calculating a difference average value for each horizontally adjacent pixel column; difference calculating means for calculating a difference value between vertically adjacent pixel columns of the difference average value; And a boundary surface position specifying means for specifying the position of the boundary surface between the anion exchange resin layer and the cation exchange resin layer from the pixel region.
[0015]
For this reason, the boundary between the anion exchange resin layer and the cation exchange resin layer in the separation tower can be correctly recognized, and the separation of the ion exchange resin in the separation tower can be automated.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a method and an apparatus for detecting an interface of 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 interface detection 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 that removes impurities such as corrosion products generated from plant constituent materials from the condensed water that has been desalinated in the desalination tower 10 is connected to a lower portion of the desalination tower 10.
[0017]
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 is connected to the desalination 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 flowing into the separation tower 20 with the flow rate control valve 21, the exchange resin is separated into two layers by utilizing the specific gravity difference between the cation exchange resin and the anion exchange resin. .
[0018]
Specifically, the anion exchange resin and the cation exchange resin flow in the separation tower 20 by backwashing. 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. A collector 23 for taking out an anion exchange resin having a small specific gravity from the exchange resins separated into two layers and transferring the extracted anion exchange resin to an anion exchange resin regeneration tower 40 is provided at a substantially central portion of the separation tower 20.
[0019]
On the side wall surface of the separation tower 20, an observation window 24 for observing the state inside the separation tower 20 is provided corresponding to the height position where the collector 23 is arranged. This observation window 24 allows the state of separation (boundary surface) of the ion exchange resin to be observed from the outside. An imaging unit 25 for observing the state of separation of the ion exchange resin 1 via the observation window 24 is attached to the observation window 24. The imaging unit 25 is attached to the observation window 24 so that an area around the collector 23 disposed 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 imaging unit 25, for example, a CCD camera or a CMOS sensor is used. Then, the data captured by the imaging unit 25 is sent to the interface detection device 30.
[0020]
The interface detection device 30 includes an image processing unit 31 that receives image data captured by the image capturing unit 25 and ranks each pixel into 256 gradation values of, for example, 0 to 255. Needless to say, the gradation values to be ranked by the image processing unit 31 are not limited to 256. Further, this gradation value may be gradation data based on the brightness of the monochromatic light, but it is preferable to colorize the image data of the image pickup section 25 from the viewpoint of improving accuracy. In this case, the image processing unit 31 may process each of the three primary colors of R (red), G (green), and B (blue) as gradation data.
[0021]
The first feature of the present invention in the device for detecting the interface of the ion exchange resin 1 thus configured is that the cation exchange resin layer 3 or the anion exchange resin layer 2 in the separation tower 20 The point is that a means is provided for determining the ratio of the anion exchange resin layer 2 and the cation exchange resin layer 3 within the imaging range by determining the proportion of the interface in the imaging range. The second feature point is that the average value in the horizontal direction is obtained from the gradation difference value for each pixel obtained by the imaging unit 25, and the difference in the average value between vertically adjacent pixel columns is the largest. The point is that the boundary surface is determined by obtaining a pixel row that satisfies
[0022]
This will be specifically described with reference to FIG. 2 showing a schematic configuration of an ion exchange resin interface detection device. The reference data holding unit 33 previously holds the reference gradation data for each type of ion exchange resin. On the other hand, image data obtained by imaging the inside of the separation tower 20 by the imaging unit 25 is sent to the image processing unit 31. The image data is decomposed for each pixel by the image processing unit 31 and stored in the gradation data holding unit 32 as gradation data.
[0023]
The arithmetic unit 34 calculates, for each pixel, the reference gradation data held in the reference data holding unit 33 and the data imaged by the imaging unit 25 and held in the gradation data holding unit 32 as the gradation data. The difference value (pixel gradation data) is calculated and held in the difference data holding unit 35.
Next, the determination unit 36 extracts a pixel signal corresponding to the anion exchange resin from the difference values (pixel gradation data) held in the difference data holding unit 35, and counts the number of pixels. Further, the determination unit 36 determines whether or not the number of pixels is within a range of a predetermined number of pixels (for example, 5% to 95%). Of course, the determination unit 36 may extract a difference value (pixel gradation data) corresponding to the cation exchange resin and determine whether the number of pixels is within a predetermined number of pixels.
[0024]
This will be described in more detail with reference to the flowchart of the ion exchange resin interface detecting device shown in FIG.
First, the imaging unit 25 provided in the observation window 24 captures image data of the state inside the separation tower, and the image processing unit 31 decomposes data for each pixel and stores the data in the data storage unit 32 (step 1). ). Then, from the data for each pixel, the arithmetic unit 34 creates gradation difference data for each pixel by comparing with the reference gradation data of the cation exchange resin held in the reference data holding unit 33 in advance. The data is held in the data holding unit 35 (step S2). From the obtained gradation difference data, the determination unit 36 counts the number N of pixels whose difference value is equal to or larger than a predetermined threshold (or equal to or smaller than the threshold). Then, the determination unit 36 determines whether the number N of pixels is within a predetermined range (for example, 5% to 95%) with respect to the number of all pixels (step S3).
[0025]
When the determination unit 36 determines, for example, that the number N of pixels is 5% or less of the total number of pixels (step S4), the cation exchange resin layer 2 is slightly recognized below the imaging range of the imaging unit 25. In this state, the interface between the cation exchange resin layer 3 and the anion exchange resin layer 2 is located below the imaging range of the imaging unit 25. Therefore, a minimum value (for example, 0) is set and output as the measured value of the boundary surface height H (step S5).
[0026]
Also, in step S4, when the determination unit 36 determines that the number N of pixels having a pixel signal corresponding to the anion exchange resin is 95% or more of the total number of pixels, for example, the imaging range of the imaging unit 25 includes: The cation exchange resin layer 3 occupies most. That is, the boundary surface between the cation exchange resin layer 3 and the anion exchange resin layer 2 is located above the imaging range of the imaging unit 25. For this reason, the maximum value (for example, 100) is set and output as the measured value of the boundary surface height H (step S6).
[0027]
Further, in step S4, for example, when the determination unit 36 determines that the number of pixels N is in the range of 5% to 95% of the total number of pixels, the anion exchange resin layer 2 and the cation exchange resin layer 3 are within the imaging range. Will exist.
When the determining unit 36 determines that the boundary surface between the anion exchange resin layer 2 and the cation exchange resin layer 3 exists within the imaging range, the calculation unit 34 adjusts the boundary surface to the position of the collector 23 in step S2. The obtained difference data for each pixel is added to each pixel row adjacent in the horizontal direction to calculate an average difference value. Then, the arithmetic unit 34 holds the obtained difference average value in the difference data holding unit 35 (Step S7).
[0028]
Using the difference average value obtained by this calculation, the calculation unit 34 further calculates a difference between vertically adjacent pixel columns (step S8). As will be described in detail later, the boundary between the anion exchange resin layer 2 and the cation exchange resin layer 3 exists at a portion of the pixel row where the difference value obtained by this operation is maximum. Then, the height H of the boundary surface can be obtained from the number of rows of the pixel column having the boundary surface at which the difference value becomes maximum (step S9).
[0029]
For example, assuming that the total number of rows of pixel columns (horizontal columns) is V, the number of rows of pixels having a boundary surface is the Xth column from the lowest row, and the height of the imaging region is L, the ion exchange resin The height H of the interface is
H = (X / V) × L
Can be obtained as If the height H of the boundary surface is made equal to the target height, for example, the height h of the collector 23 with reference to the lowermost end of the imaging region, the bottom of the anion exchange resin layer 2 is adjusted to the position of the collector 23. be able to. As a result, only the anion exchange resin can be extracted from the separation tower 20 and transferred to the anion exchange resin regeneration tower 40.
[0030]
Here, the target height may be the height h of the collector 23. However, if the target height is set to a position [1 to 10 cm] below the collector 23, the cation exchange resin is not mixed. This is preferable because only the separated anion exchange resin can be reliably transferred. In the following description, the adjustment target height of the height H of the boundary surface is assumed to be the height h of the collector 23 for convenience.
[0031]
For this reason, the determination unit 36 determines the height h of the collector in Step 10 and the height H of the boundary surface of the ion-exchange resin layer obtained in Step S5, S6, or S9. When the height H of the boundary surface of the ion exchange resin layer is lower than the height h of the collector 23 (H <h), the position of the boundary surface is lower than the collector 23. For this reason, the opening degree of the flow control valve 21 is increased to increase the flow rate of the backwash water, and the position of the boundary surface is further increased. (Step S11).
[0032]
Conversely, when the height H of the boundary surface of the ion exchange resin layer is higher than the height h of the collector 23 (H> h) in Step 10, the position of the boundary surface is higher than the collector 23. For this reason, the opening degree of the flow control valve 21 is reduced to reduce the flow rate of the backwash water, thereby lowering the position of the boundary surface (step S12).
Since the interface height H (minimum value) obtained in step S5 is lower than the height h of the collector 23, the flow rate (water supply amount) of the backwash water is increased, the interface height is increased, and step S1 is performed again. Then, the height of the boundary surface is measured through the steps described above. Similarly, since the boundary surface height H (maximum value) obtained in step S6 is higher than the height of the collector 23, the amount of water supply is reduced, the boundary surface height is lowered, and the process returns to step S1 again. Is repeated to measure the interface height. At any time due to a change in the water supply amount, the height H of the boundary surface enters the imaging area of the imaging unit 25, and reaches the step S7. Subsequently, the water supply amount is controlled through steps S8 and S9 until the height H of the boundary surface coincides with the height h of the collector 23 in step S10.
[0033]
When it is determined in step 10 that the height H of the boundary surface of the ion-exchange resin layer is substantially equal to the height h of the collector 23 (H ≒ h), the anion-exchange resin is anion-exchanged through the collector 23. The transfer processing is performed to the exchange resin regeneration tower 40 (step S13). The transition to the transfer processing is preferably performed when the state in which the boundary surface height H is substantially equal to the height h of the collector 23 continues for a predetermined time (H = h in several cycles of steps S1 to S12). Mistakes can be prevented. Then, the anion exchange resin transferred to the anion exchange resin regeneration tower 40 by a conventional method and the cation exchange resin remaining in the separation tower 20 are subjected to regeneration treatment in the respective towers. After the regeneration treatment, the anion exchange resin and the cation exchange resin are transferred and stored in the resin storage tank 50, taken out when necessary, and sent to the desalination tower 10.
[0034]
The change (control) of the water supply amount is obtained by inputting the measured value of the boundary surface height H obtained in step S5, S6 or step S9 to the control device 38 via the output unit 37, and comparing the measured value with the target height of the boundary surface. To calculate and output the control value (valve opening). As the control device 38, a sequencer, a PID controller, or the like can be used alone or in appropriate combination. Of course, the control device 38 may be built in the interface detection device 30.
[0035]
Here, the fact that a boundary surface can be detected from steps S8 and S9 described above will be further described in detail with reference to the pixel data of FIG. On the basis of the anion exchange resin, difference data between the reference pixel signal and the image gradation data photographed by the imaging unit 25 is calculated by the calculation unit 34, and the difference data is calculated as pixel gradation data for each pixel as shown in FIG. It is stored in the holding unit 35. As described above, the anion exchange resin layer 2 having a small specific gravity is formed on the upper part of the separation tower 20, and the cation exchange resin layer 3 having a large specific gravity is formed on the lower part. Since the imaging data of the portion of the anion exchange resin layer 2 has no difference from the reference gradation data of the anion exchange resin, the imaging data indicates [0] or a value in the vicinity thereof.
[0036]
On the other hand, the difference between the pixel area where the cation exchange resin layer 3 is imaged and the reference gradation data of the anion exchange resin is large. FIG. 4 illustrates the difference (pixel gradation data) between the gradation data of the cation exchange resin and the reference gradation data of the anion exchange resin as, for example, [50]. Actually, the pixel gradation data (difference value) shows a value near [50] depending on the degree of light reflection, the state of the resin, and the like.
[0037]
Further, a mixed layer in which the respective resins are mixed is formed on the boundary surface between the anion exchange resin layer 2 and the cation exchange resin layer 3. Since the mixed layer contains an anion exchange resin and a cation exchange resin, the pixel gradation data (difference value) becomes a value near [0] in the pixel region where the anion exchange resin is imaged, In the pixel region where the exchange resin layer is imaged, the value is around [50].
[0038]
The arithmetic unit 34 adds up the pixel gradation data obtained in this manner for each pixel adjacent in the horizontal direction, and holds the average value in the difference data holding unit 35. Based on the obtained average value data, the arithmetic unit 34 calculates a difference between the average values of the vertically adjacent pixel columns, and stores the average difference value in the difference data holding unit 35 as an average difference value.
The pixel row having the largest average difference value among the average difference values obtained in this manner is the boundary between the anion exchange resin layer 2 and the cation exchange resin layer 3. Therefore, the boundary between the anion exchange resin layer 2 and the cation exchange resin layer 3 can be obtained by the determination unit 36 determining the pixel row having the largest average difference value.
[0039]
According to the method and the apparatus for detecting the boundary surface of the ion-exchange resin thus configured, the average value in the horizontal direction is obtained from the gradation difference value for each pixel obtained by the imaging unit 25. Since the pixel row that maximizes the difference between the average values of the vertically adjacent pixel rows is obtained, the position of the boundary surface of the ion exchange resin layer can be reliably detected.
[0040]
In addition, since the site where the boundary surface is located is determined from the ratio of the anion exchange resin layer 2 or the cation exchange resin layer 3 occupying the imaging range of the imaging unit 25, the ion exchange resin imaged by the imaging unit 25 is Even in a situation where only the anion exchange resin layer 2 or the cation exchange resin layer 3 is present, there is no possibility of erroneous detection of the boundary surface based on the binarized data as in the related art.
[0041]
For this reason, automatic processing of separation of the ion exchange resin can be easily and reliably performed.
The present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the gist of the invention.
[0042]
【The invention's effect】
As described above, according to the method and the apparatus for detecting an interface of an ion-exchange resin of the present invention, the cation-exchange resin layer or the anion-exchange resin layer occupies the imaging range of the imaging unit that images the vicinity of the collector in the separation tower. Since the ratio (area) is determined, it can be correctly determined whether or not there is an interface between the anion exchange resin layer and the cation exchange resin layer.
[0043]
In addition, since the boundary surface of the ion-exchange resin is obtained from a portion where the difference in the average value of the gradation difference data between the vertically adjacent pixel columns is maximized, the position of the boundary surface can be reliably detected. It becomes possible.
In particular, even when the ion-exchange resin imaged by the imaging unit has only the anion-exchange resin layer or the cation-exchange resin layer, the boundary surface of the ion-exchange resin is detected by the average difference value for each pixel column. Therefore, erroneous detection of the boundary surface does not occur.
[0044]
Therefore, there can be obtained a great effect in practical use, for example, such that the separation process of the ion exchange resin can be easily and reliably performed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a condensate desalination device for a power plant using an ion exchange resin interface detection device according to an embodiment of the present invention.
FIG. 2 is a diagram showing a schematic configuration of an ion-exchange resin interface detection device according to an embodiment of the present invention.
FIG. 3 is a flowchart showing a method for detecting an interface of an ion exchange resin according to an embodiment of the present invention.
FIG. 4 is a diagram showing an example of imaging data of an ion exchange resin according to one embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 20 separation tower 21 flow control valve 25 imaging unit 30 interface detection device 31 image processing unit 32 data storage unit 32 gradation data storage unit 33 reference data storage unit 34 operation unit 35 difference data storage unit 36 determination unit 37 valve control unit

Claims (4)

An interface detection method for detecting an interface between an anion exchange resin layer and a cation exchange resin layer separated by flowing backwash water through an ion exchange resin layer containing an anion exchange resin and a cation exchange resin filled in a separation tower. So,
An imaging step of imaging the ion-exchange resin layer filled in the separation tower from its side to obtain an image of the ion-exchange resin layer in a predetermined area at a predetermined height position in the separation tower,
A pixel determination step of determining pixel signals constituting an image obtained in the imaging step to determine a pixel signal corresponding to the anion exchange resin and / or the cation exchange resin;
An anion exchange resin layer and / or a cation exchange resin layer in the image are obtained from the number of pixels of a pixel signal corresponding to the anion exchange resin and / or the cation exchange resin or an area ratio of the pixel signal in a predetermined region of the image. A resin determination step,
A boundary surface determination step of determining a boundary surface between the anion exchange resin layer and the cation exchange resin layer within the imaging range of the image according to the determined resin layer. . The boundary surface determination step is a difference data conversion step of calculating a difference value between the pixel signal obtained in the pixel determination step and a reference pixel signal of the anion exchange resin and / or the cation exchange resin held in advance,
An average value calculation step of calculating a difference average value for each pixel row adjacent in the horizontal direction of the difference value obtained in the difference data conversion step,
A difference calculation step of calculating a difference between vertically adjacent pixel columns of the difference average value calculated in the average value calculation step,
A boundary surface position specifying step of specifying a position of a boundary surface between the anion exchange resin layer and the cation exchange resin layer from a pixel region in which a difference value obtained in the difference calculation step is maximum. Item 4. The method for detecting an interface of an ion exchange resin according to Item 1. An image of the ion-exchange resin layer containing the anion-exchange resin and the cation-exchange resin filled in the separation tower is taken from the side, and an image of the ion-exchange resin layer in a predetermined area at a predetermined height position in the separation tower is obtained. Imaging means to be sought;
Pixel determination means for determining a pixel signal constituting an image obtained by the imaging means to determine a pixel signal corresponding to the anion exchange resin and / or the cation exchange resin;
An anion exchange resin layer and / or a cation exchange resin layer in the image are obtained from the number of pixels of a pixel signal corresponding to the anion exchange resin and / or the cation exchange resin or an area ratio of the pixel signal in a predetermined region of the image. Resin determination means,
An interface detection device for an ion-exchange resin, comprising: a boundary surface determination unit configured to determine a boundary surface between an anion exchange resin layer and a cation exchange resin layer within an imaging range of the image according to the determined resin layer. . The boundary surface determining unit is a difference data converting unit that calculates a difference value between a pixel signal obtained by the pixel determining unit and a reference pixel signal of the anion exchange resin and / or the cation exchange resin held in advance.
Average value calculation means for calculating a difference average value for each pixel column adjacent in the horizontal direction of the difference value obtained by the difference data conversion means,
Difference calculating means for calculating a difference between vertically adjacent pixel columns of the difference average value calculated by the average value calculating means,
A boundary surface position specifying unit that specifies a position of a boundary surface between the anion exchange resin layer and the cation exchange resin layer from a pixel region in which a difference value obtained by the difference calculation unit is maximum. Item 4. An apparatus for detecting an interface of an ion exchange resin according to Item 3.

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