JP2004113894A - Method and apparatus for producing hollow fiber membrane module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method which can detect the occurrence of interrupted thread and the degree of the occurrence and exactly judge whether a hollow fiber membrane module is acceptable or not in the production of the membrane module and an apparatus for the method. <P>SOLUTION: The potting end surface of a tested hollow fiber membrane module is imaged, and regional information on a part where a hollow fiber membrane exists and a part where a resin exists is obtained from the obtained image. From two kinds of regional information, the area of the hollow fiber membrane with the end parts closed is obtained. When the obtained area exceeds a preset threshold, the tested module is judge to be defective. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a hollow fiber membrane module that can be used for an artificial dialyzer, a wastewater treatment device, a water purifier, and the like.
[0002]
[Prior art]
As is well known, for example, a hollow fiber membrane module stores a yarn bundle of a hollow fiber membrane (hollow semi-permeable membrane) having both ends opened in a container having both ends or one end opened, and At both ends, the gap between the container and the hollow fiber membrane is sealed with a resin. The sealing with the resin is performed by pouring (potting) the resin into a space between the container and the yarn bundle and allowing the potting resin to penetrate around each hollow fiber membrane. Potting resin may enter inside and the ends may be closed. The closed hollow fiber membrane becomes a so-called impervious thread. When such impervious thread is present, for example, in the case of an artificial dialyzer, blood flowing into the hollow fiber membrane remains in the hollow fiber membrane, and the dialysis performance is reduced. And if it is significant, sufficient artificial dialysis cannot be performed. Therefore, it is necessary to remove a hollow fiber membrane module in which a certain number or more of non-threaded yarns exist from the production line as a defective product.
[0003]
By the way, conventionally, the determination of the quality of a hollow fiber membrane module related to the occurrence of a non-threaded yarn is based on the fact that the occurrence of the non-threaded yarn is correlated with a group of minute bubbles generated in the potting resin due to improper potting. According to the concept, the potting end face is imaged by a CCD camera, and a bubble group is detected (for example, see Patent Document 1).
[0004]
[Patent Document 1]
However, such a conventional technology detects the presence or absence of minute air bubbles in the potting resin and does not directly detect the presence or absence of a non-threaded yarn. I can't tell you. In addition, since there is not always a correlation between the occurrence of the non-through yarn and the occurrence of the bubble group, a problem remains in terms of accuracy.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a method and an apparatus capable of knowing whether or not a non-threaded yarn has occurred and the degree of the occurrence in the production of a hollow fiber membrane module and accurately determining the quality. .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention takes an image of the potting end face of the test hollow fiber membrane module, obtains the area information of the part where the hollow fiber membrane is present and the part where the resin is present from the obtained image, The area of the hollow fiber membrane whose end is closed is obtained from the obtained two types of area information, and the hollow fiber membrane module to be tested is determined to be defective when the area exceeds a predetermined threshold. A method for producing a hollow fiber membrane module is provided. At this time, it is preferable to irradiate light to the potting end face of the test hollow fiber membrane module, capture scattered light from the potting end face, and obtain area information of a portion where the hollow fiber membrane exists from the obtained image. At this time, the potting end face may be irradiated with light in the ultraviolet band, preferably light of a single wavelength. Furthermore, it is also preferable to irradiate light to the potting end face of the test hollow fiber membrane module, capture regular reflection light from the potting end face, and obtain area information of a portion where the resin is present from the obtained image.
[0007]
Further, in order to achieve the above object, the present invention provides first and second imaging means for imaging a potting end face of a hollow fiber membrane module to be tested, and a hollow fiber from an image obtained by the first imaging means. A means for obtaining region information of a portion where a film is present, a means for obtaining region information of a portion where a resin is present from an image obtained by the second imaging means, and an end portion which is closed from the obtained two pieces of region information. Means for obtaining the area of the hollow fiber membrane, means for comparing the area with a predetermined threshold value, and means for testing the hollow fiber when the area of the hollow fiber membrane whose end is closed exceeds the predetermined threshold value. Means for determining that the fiber membrane module is defective is provided. It is preferable to provide a light irradiating means for irradiating the potting end face of the test hollow fiber membrane module with light corresponding to the first imaging means. In that case, the light irradiation means preferably includes a low-pressure mercury lamp. Further, it is preferable that the first and second imaging means are line sensor cameras.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
In FIG. 1, a manufacturing apparatus for a hollow fiber membrane module includes a measuring table 1 having a module supporting means 1a and a module moving means 1b, a measuring table 2 having a module supporting means 2a and a module moving means 2b, and a module transferring apparatus. Device 3, a light irradiation device 4 having a light source 4a and a power supply 4b, a light irradiation device 5 having a light source 5a and a power supply 5b, imaging devices 6, 7, an image processing device 8, an operation command device 9, , A display device 10. Hereinafter, the configuration of each of these units will be described in detail together with the operation thereof.
Measuring table 1:
The module supporting means 1a supports a hollow fiber membrane module M to be tested (hereinafter, referred to as a module M) carried by a module transfer device 3, which will be described later. That is, the center of the potting end face of the module M can be made to coincide with the optical center of the imaging device 6 described later by moving the position up and down and left and right according to the outer diameter and the length. Further, in this embodiment, since a line sensor camera is used as the imaging device 6, the module moving means 1b is provided so that the module M can be moved in the horizontal direction at a predetermined speed.
Measuring table 2:
The module supporting means 2a supports the module M carried from the measuring table 1 by a module transfer device 3 described later, and adjusts the inclination of the module M and its size, that is, its outer diameter and length. The center of the potting end surface of the module M can be made to coincide with the optical center of the image pickup device 7 described later by moving the position up, down, left, and right according to. Further, in this embodiment, since a line sensor camera is used as the imaging device 7, the module moving means 2b is provided so that the module M can be moved in the horizontal direction at a predetermined speed.
Light irradiation device 4:
The light irradiation device 4 includes a light source 4a and a power supply 4b. In this embodiment, a ring-shaped low-pressure mercury lamp that generates near-ultraviolet light having a wavelength of 368 nm is used as the light source 4a. It is preferable to use a light source having a wavelength in the ultraviolet band and a single wavelength in order to obtain a clear image of the potting end face. The power supply 4b turns on / off the light source 4a and adjusts the amount of light according to a command from an operation command device 9 described later.
Light irradiation device 5:
The light irradiation device 5 includes a light source 5a and a power supply 5b. In this embodiment, a line-type optical fiber light guide is used as the light source 5a, and the angle of incidence of the light source 5a with respect to the potting end face of the module M and the angle of reflection from the potting end face of the module M of the imaging device 7 described later are equal. In this way, specularly reflected light from the potting end face is obtained. The power supply 5b turns on / off the light source 5a and adjusts the amount of light according to a command from an operation command device 9 described later.
Imaging device 6:
The imaging device 6 is for photographing the end face of the potting of the module M on the measuring table 1 and obtaining an image related to the area information of the portion where the hollow fiber membrane exists. In this embodiment, a 5,000 pixel line is used. A sensor camera is used.
Imaging device 7:
The imaging device 7 is for taking an image of the potting end face of the module M on the measuring table 2 and obtaining an image related to the area information of the portion where the resin is present. In this embodiment, a 5,000 pixel line sensor camera Is used.
Image processing device 8:
The image processing device 8 processes the image of the potting end face of the module M photographed by the imaging devices 6 and 7, and determines the presence / absence of non-threading and the quality of the module M. The flow of the processing by the image processing device 8 is as shown in FIG.
[0009]
In FIG. 2, first, the image input from the imaging device 6 to the image processing device 8 is subjected to a binarization process, and the entire view of the potting end face of the module M is converted into a white pixel and the background portion is converted into a binary image of black pixels. Convert. Then, from this binarized image, the center of gravity of the whole panoramic portion that is circular is obtained. Further, the position of the potting end face is detected based on the barycentric coordinates and the diameter information of the potting end face of the module M set in advance.
[0010]
The high-pass filter performs pre-processing so that the thick region of the hollow fiber membrane is emphasized.
By this pre-processing, the image is enhanced with only the hollow fiber membrane.
[0011]
Next, the pre-processed image is binarized by a predetermined threshold value, and the hollow fiber membrane portion is a binary image of white pixels, and the hollow portion of the hollow fiber membrane and the resin portion are black pixels.
[0012]
Next, a labeling process is performed to label a region of a black pixel within a range of an arbitrary area. Further, for example, expansion processing of 10 pixels, for example, reduction processing of 7 pixels is performed. Thus, an image in which the region where the hollow fiber membrane exists is a white pixel, and the region where the resin exists is a black pixel is obtained.
[0013]
On the other hand, the image input from the imaging device 7 to the image processing device 8 is subjected to binarization processing to convert the entire view of the potting end face of the module M into white pixels and the background portion into black pixels. Then, from the binarized image, the barycentric coordinates of the circular coordinates surrounding the whole view portion are obtained. Further, the position of the potting end face is detected based on the barycentric coordinates and the diameter information of the potting end face of the module M set in advance.
[0014]
Next, in order to extract a portion other than the specular reflection, that is, a hollow portion of the hollow fiber membrane, a portion having a high luminance is removed by a differential filter, a specular reflection portion is set to a black pixel by a predetermined threshold, and the other portion is set to a white pixel. A binarization process for classifying pixels is performed. In addition, expansion and contraction processing is performed on the white pixel portion, and the hollow portions of the hollow fiber membrane are joined to each other to extract the yarn bundle of the hollow fiber membrane as one region.
[0015]
Next, by the difference processing, the region where the hollow fiber membrane is present and the reflectance is high, that is, the impervious yarn portion, is determined from the image generated from the image by the imaging device 8 and the image generated from the image by the imaging device 7. Extract.
[0016]
Finally, the module M is determined. If the area of the extracted region does not exceed a predetermined threshold, the module is determined to be non-defective, and if so, it is determined to be defective.
Operation command device 9:
The operation command device 9 sends a command to the image processing device 8 corresponding to the difference in the outer diameter of the module M, the outer diameter and the inner diameter of the hollow fiber membrane, the assembling method, etc., and converts the index value or the binarization suitable for the module M. , A high-pass filter coefficient, etc. are set, and a command is sent to the power supplies 4b, 5b of the light irradiation devices 4, 5 to turn on / off the light sources 4a, 5a and adjust the light amount. Further, a command is sent to the module supporting devices 1 and 2 to control the module moving devices 1b and 2b so that the module M moves at a speed suitable for photographing by the imaging devices 6 and 7.
Display device 10:
The display device 10 displays an inspection result in which the non-threaded portion is marked in an image.
Module transfer device 3:
The module transfer device 3 mounts the module M on the module supporting means 1a. Further, the module M after the image pickup by the image pickup device 6 is transferred to the module supporting means 2a. After the inspection is completed, the module M is transferred to a subsequent process when it is determined that the module M is non-defective, and is removed from the production line when it is determined that the module M is defective, according to a command from the operation command device 9.
[0017]
Now, in order to explain the present invention in more detail based on a more specific example, FIG. 3 is an image of the potting end face of the module M taken by the imaging device 6. When this image is subjected to a binarization process using a predetermined threshold value in the image processing device 8, a binarized image shown in FIG. 4 is obtained. When the center of gravity of the circular white pixel region is obtained from this image and a circular region having a radius R of the potting end surface of the module M is cut out from the center of gravity, an image shown in FIG. 5 is obtained. This image is subjected to a high-pass filter for emphasizing the thick portion of the hollow fiber membrane, and is binarized with a predetermined threshold, to obtain an image shown in FIG.
[0018]
Next, a circular region surrounded by a thick portion is extracted from the image shown in FIG. 6 based on the area of the black pixel region and various measurement results, and the extracted image of the circular region is expanded at a predetermined distance setting. Then, a contraction process is performed to obtain an image shown in FIG.
[0019]
FIG. 8 is an image of the potting end face of the module M taken by the imaging device 7. When the image processing device 8 performs a binarization process on the image at a predetermined threshold value, a binary image shown in FIG. 9 is obtained.
[0020]
Next, the center shown in FIG. 10 is obtained by obtaining the center of gravity of the circular white pixel area and cutting out a circular area having a radius R on the end face of the module M from the center of gravity. When this image is subjected to a high-pass filter that emphasizes the hollow portion of the hollow fiber membrane and binarized using a predetermined threshold value, an image shown in FIG. 11 is obtained.
[0021]
Next, expansion and contraction processing is performed on the image shown in FIG. 11 at a predetermined distance setting to obtain an image shown in FIG. Then, a difference process is performed between the image shown in FIG. 7 and the image shown in FIG. 12 to obtain the image shown in FIG. Then, the number of hollow fiber membranes corresponding to the maximum value of the area of the remaining area was determined. As a result, in FIG. 13, an impervious yarn bundle area corresponding to 11 hollow fiber membranes was detected.
[0022]
Finally, as a result of comparing the number of defective yarns of the hollow fiber membrane with the defective product determination threshold value (10 in this example) of the module M, the number of defective yarns exceeded the threshold value. And was excluded from the manufacturing process.
[0023]
The method for manufacturing a hollow fiber membrane module according to the present invention can be applied to the case of manufacturing a hollow fiber membrane module such as an artificial dialyzer, a sewage treatment device, and a water purifier used in ordinary households.
[0024]
【The invention's effect】
The present invention takes an image of a potting end face of a hollow fiber membrane module to be tested, obtains region information of a portion where a hollow fiber membrane exists and a region where a resin exists from the obtained image, and obtains two types of obtained region information. The area of the hollow fiber membrane whose end is closed is obtained from, and when the area exceeds a predetermined threshold value, the test hollow fiber membrane module is determined to be defective, as in the prior art. Since the determination is not based on indirect information such as the presence / absence of a microbubble group in the potting resin, the quality can be accurately determined.
[Brief description of the drawings]
FIG. 1 is a schematic front view of an apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a processing flow in an image processing apparatus of the apparatus shown in FIG.
FIG. 3 is an image of a potting end face taken by the imaging device 6 shown in FIG.
FIG. 4 is a binarized image of the image shown in FIG.
FIG. 5 is an image obtained by cutting out only the end face portion from the image shown in FIG. 3;
6 is an image obtained by applying a high-pass filter to the image shown in FIG. 5 and then performing binarization processing.
FIG. 7 is an image obtained by detecting a region corresponding to a hollow fiber membrane portion from the image shown in FIG. 5 and performing expansion and contraction processing.
FIG. 8 is an image of a potting end face taken by the imaging device 7 shown in FIG.
FIG. 9 is a binarized image of the image shown in FIG. 8;
FIG. 10 is an image obtained by cutting out only the end face portion from the image shown in FIG. 8;
FIG. 11 is an image obtained by applying a high-pass filter to the image shown in FIG. 10 and then performing binarization processing.
FIG. 12 is an image obtained by subjecting the image shown in FIG. 11 to expansion and contraction processing.
13 is an image obtained by performing a difference process between the image shown in FIG. 12 and the image shown in FIG. 7;
[Explanation of symbols]
M: hollow fiber membrane module to be tested 1: measuring table 1a: module supporting means 1b: module moving means 2: measuring table 2a: module supporting means 2b: module moving means 3: module transferring device 4: light irradiation device 4a: Light source 4b: power supply 5: light irradiation device 5a: light source 5b: power supply 6: imaging device 7: imaging device 8: image processing device 9: operation command device 10: display device

Claims (10)

The potting end face of the hollow fiber membrane module to be tested is imaged, and from the obtained image, the area information of the part where the hollow fiber membrane is present and the area where the resin is present are obtained. A method for manufacturing a hollow fiber membrane module, comprising: determining an area of a closed hollow fiber membrane; and determining that the test hollow fiber membrane module is defective when the area exceeds a predetermined threshold. The potting end face of the test hollow fiber membrane module is irradiated with light, and scattered light from the potting end face is imaged, and the area information of the portion where the hollow fiber membrane is present is obtained from the obtained image. A method for manufacturing a hollow fiber membrane module. The method for manufacturing a hollow fiber membrane module according to claim 2, wherein the potting end face is irradiated with light in an ultraviolet band. The method for manufacturing a hollow fiber membrane module according to claim 2, wherein the potting end face is irradiated with light having a single wavelength. The hollow according to claim 1, wherein the hollow fiber membrane module under test is irradiated with light and the specularly reflected light from the potting end face is imaged, and area information of a portion where the resin is present is obtained from the obtained image. Manufacturing method of thread membrane module. First and second imaging means for imaging the potting end surface of the hollow fiber membrane module to be tested, means for obtaining region information of a portion where the hollow fiber membrane exists from an image obtained by the first imaging means, Means for obtaining area information of the portion where the resin is present from the image obtained by the imaging means of No. 2, means for obtaining the area of the hollow fiber membrane whose end is closed from the obtained two pieces of area information, A means for comparing with a predetermined threshold value, and a means for judging the test hollow fiber membrane module as defective when the area of the hollow fiber membrane whose end is closed exceeds a predetermined threshold value. An apparatus for manufacturing a hollow fiber membrane module. The apparatus for producing a hollow fiber membrane module according to claim 6, further comprising a light irradiating means for irradiating light to a potting end face of the test hollow fiber membrane module corresponding to the first imaging means. The apparatus for manufacturing a hollow fiber membrane module according to claim 7, wherein the light irradiation means includes a low-pressure mercury lamp. The apparatus for manufacturing a hollow fiber membrane module according to claim 6 or 7, wherein the first and second imaging means are line sensor cameras. A hollow fiber membrane module manufactured using the method according to any one of claims 1 to 5 or the apparatus according to any one of claims 6 to 9.

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