KR20210030637A - Analysis method of membrane spiral element - Google Patents

Abstract

The present specification provides a separation membrane spiral wound element analysis method.

Description

Separation membrane spiral wound element analysis method {ANALYSIS METHOD OF MEMBRANE SPIRAL ELEMENT}

The present specification relates to a separation membrane spiral wound element analysis method.

The phenomenon that the solvent moves through the separation membrane from the solution with the low solute concentration to the high solution between the two solutions separated by the semi-permeable membrane is called the osmotic phenomenon.At this time, the pressure acting on the solution side with the high solute concentration due to the movement of the solvent Is called osmotic pressure. However, when an external pressure higher than the osmotic pressure is applied, the solvent moves toward a solution with a low solute concentration, and this phenomenon is called reverse osmosis. Using the reverse osmosis principle, various salts or organic substances can be separated through a semi-permeable membrane using a pressure gradient as a driving force. Reverse osmosis membranes using the reverse osmosis phenomenon are used to separate substances at the molecular level and remove salts from salt water or seawater to supply water for households, construction, and industrial use.

A representative example of such a reverse osmosis membrane may be a polyamide-based water treatment separation membrane, and the polyamide-based water treatment separation membrane is manufactured by forming a polyamide active layer on a microporous layer support, and more specifically, polysulfurization on a nonwoven fabric. A phone layer is formed to form a microporous support, and the microporous support is immersed in an aqueous solution of m-phenylene diamine (mPD) to form an mPD layer, which is again trimesoyl chloride (TMC). ) It is prepared by a method of forming a polyamide layer by immersing in an organic solvent to contact the mPD layer with TMC and interfacial polymerization.

Korean Patent Publication No. 10-2014-0107214

The present specification provides a separation membrane spiral wound element analysis method.

An exemplary embodiment of the present specification is a step of obtaining a cross-sectional image of the spiral wound separation membrane element with a computerized tomography (CT) device; And it provides a separation membrane spiral wound element analysis method comprising the step of analyzing the gap between the flow path members included in the separation membrane spiral wound element using a computer image analysis method (computational image analysis) of the cross-sectional image of the spiral wound separation membrane element.

In the case of using the separation membrane spiral wound element analysis method according to the present specification, it is possible to visually and quantitatively analyze the gap between the flow path members included in the separation membrane spiral wound element without disassembling and disassembling the separation membrane spiral wound element.

1 is an image taken by a computed tomography apparatus of a spiral wound element of a separation membrane.
2 is a pre-processing to analyze the original image captured by the computed tomography apparatus of the spiral wound element of the separator.
3 and 4 are images taken by a computed tomography apparatus of a spiral wound element of a separation membrane, and analyzed by computational image analysis.
5 is a histogram chart quantitatively analyzing the spacing between flow path members included in the spiral wound element of the separation membrane.
6 is a diagram illustrating a spiral wound separator element according to an exemplary embodiment of the present specification.

In this specification, when a member is positioned "on" another member, this includes not only the case where the member is in contact with the other member, but also the case where another member exists between the two members.

In the present specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

Hereinafter, the present specification will be described in more detail.

In an exemplary embodiment of the present specification, the separation membrane spiral wound element includes a separation membrane; Supply spacer; And a separator leaf including a permeable spacer, wherein the separator leaf is wound around a center tube.

In the exemplary embodiment of the present specification, the separation membrane is folded in half, a supply passage is formed on the inner surface of the folded separation membrane, and a permeation passage is formed on the outer surface of the folded separation membrane, and the supply-side channel member comprises the A separation membrane leaf positioned in the supply passage and the permeate-side passage member may be applied to the permeate passage.

In yet another exemplary embodiment of the present specification, the separation membrane is folded in half, a permeation passage is formed on the inner surface of the folded separation membrane, a supply passage is formed on the outer surface of the folded separation membrane, and the supply side flow path A separator leaf may be applied, wherein the material is located in the supply passage, and the permeate-side channel member is located in the transmission passage.

As an example, the separation membrane leaf may be wound around the center tube in a roll form to be manufactured as a spiral wound-type separation membrane element, but is not limited thereto.

In the exemplary embodiment of the present specification, the separation membrane spiral wound element may include one or more separation membrane leaves. Specifically, 1 to 100 may be included, preferably 1 to 50 may be included, and more preferably 15 to 30 may be included. As another example, it may include 1 to 3.

The standard of the spiral wound membrane element is not particularly limited, but may be, for example, 8 inches in diameter and 40 inches in length, 1.8 inches in diameter, and 8 to 14 inches in length.

In the exemplary embodiment of the present specification, the separation membrane spiral wound element includes a central tube, and the reverse osmosis membrane leaf is wound outside the central tube. The reverse osmosis membrane leaf wound on the outside of the center tube may mean that the reverse osmosis membrane leaf is wound.

In the exemplary embodiment of the present specification, the central pipe may be expressed as a core tube, and the central pipe serves as a passage through which filtered product water (purified water) is introduced and discharged.

The shape of the center tube is not particularly limited, but is preferably located at the center of the spiral wound element of the separation membrane. In addition, one side of the center pipe may be opened so that the product water can be discharged.

In an exemplary embodiment of the present specification, the central pipe may include a plurality of voids, and when water treatment is performed by the separation membrane spiral wound element according to an exemplary embodiment of the present specification, the number of production is After flowing into the inside of the central pipe through the flow, the introduced product water is discharged through an open side of the central pipe.

The material of the center pipe is not particularly limited, and a general material known in this field may be used.

An exemplary embodiment of the present specification is a step of obtaining a cross-sectional image of the spiral wound separation membrane element with a computerized tomography (CT) device; And it provides a separation membrane spiral wound element analysis method comprising the step of analyzing the gap between the flow path members included in the separation membrane spiral wound element using a computer image analysis method (computational image analysis) of the cross-sectional image of the spiral wound separation membrane element.

A general separation membrane element for water treatment is manufactured in a spiral wound type, and the separation membrane spiral wound element is manufactured by winding a plurality of separation membranes and channel members around a central tube. During a winding process for manufacturing an element, the flow path member may be partially deformed under pressure. Since the spacing of the flow path members included in the element has a great influence on the differential pressure of the element, a method of analyzing the gap between the flow path members is important in analyzing the performance of the finally manufactured membrane spiral wound element.

Conventionally, in order to analyze the spacing between the flow path members included in the element, the elements had to be disassembled, and thus the disassembled elements could not be reused. In addition, when the element is disassembled, the structure inside the element collapses, making it difficult to accurately measure the spacing between the flow path members. That is, it was difficult to accurately analyze the spacing between the flow path members in the element in a state in which pressure was applied during the element manufacturing process.

On the other hand, the separation membrane spiral wound element analysis method according to the present specification can visually and quantitatively analyze the gap between the flow path members without disassembling the manufactured separation membrane element. That is, through the separation membrane spiral-wound element analysis method according to the present specification, it is possible to predict the difference in performance of the element and the flow path material gap measurement to predict the differential pressure, and ultimately, whether the element is defective or not can be detected without decomposition of the separation membrane element .

In the present specification, a computerized tomography (CT) apparatus may employ a known general apparatus, but specifically a VTOMEX m300 may be used.

According to an exemplary embodiment of the present specification, the step of obtaining a cross-sectional image of the separation membrane spiral wound element with the computerized tomography (CT) device includes X-rays (X -ray) provides a separation membrane spiral wound element analysis method to obtain a cross-sectional image of the separation membrane spiral wound element by photographing.

The cross-sectional image of the separation membrane spiral wound element may mean a cross-sectional image of the separation membrane spiral wound element in a transverse direction.

Specifically, the computed tomography apparatus may be located outside the separation membrane spiral wound element so that X-rays can be irradiated in a direction perpendicular to the separation membrane spiral wound element.

A rail may be installed in a position parallel to the separation membrane spiral wound element so that the computed tomography apparatus can move in a longitudinal direction of the separation membrane spiral wound element, and a computed tomography apparatus may be connected to the rail.

Conditions when using the computed tomography apparatus are not particularly limited, and if the resolution is to be increased, the magnification may be increased, and the brightness of the image may be adjusted using X-ray power.

In the present specification, analyzing the cross-sectional image of the spiral wound element of the separation membrane by computational image analysis means that the data obtained by the computed tomography apparatus is used as intuitive visual data to measure the distance between channel members in the element. Means that.

In order to quantify the obtained cross-sectional images of the separation membrane spiral wound element with a computerized tomography (CT) device and analyze it with high accuracy, a computational image analysis method described below is applied.

According to an exemplary embodiment of the present specification, the step of analyzing the spacing between the flow path members included in the separator spiral wound element includes a cross-sectional image of the separator spiral wound element as a computer of a 2-D binary image. A separation membrane spiral wound element analysis method is provided which analyzes the spacing between channel members included in the separation membrane spiral wound element by a computational image analysis method using a computational Euclidean distance transform method.

Computational image analysis using a computational Euclidean distance transform method of the 2-D binary image is generally applied when calculating the distance between two points. By analyzing the obtained cross-sectional images of the spiral wound element of the separator by using the Euclidean distance conversion method, it is possible to analyze the gap between the flow path members.

According to an exemplary embodiment of the present specification, the step of analyzing the spacing between the flow path members included in the separator spiral wound element includes converting the cross-sectional image of the separator spiral wound element into grayscale, and then a two-dimensional binary image (2 A separation membrane spiral element analysis method comprising the step of calculating by computational image analysis using a computational Euclidean distance transform method of -D binary image) and storing it as imaged data. Provides.

In the step of analyzing the spacing between the flow path members included in the spiral wound element of the separation membrane by the computational image analysis method, steps to be described later may be sequentially applied.

From the cross-sectional image of the spiral wound element obtained by the computed tomography apparatus, portions and noises that are not to be analyzed in the original may be removed through pre-processing. The parts not analyzed in the original mean FRP (Fiber Reinforced Plastics) inside and outside the core tube.

Thereafter, an image representing the distance between channel members in color bars is obtained by a computational Euclidean distance transform method of a 2-D binary image. After converting the analyzed image to grayscale, the calculated spacing of the channel members is expressed as a histogram distribution chart, so that the spacing between the channel members included in the spiral wound element of the separator can be quantitatively analyzed.

An exemplary embodiment of the present specification provides a separation membrane spiral wound element analysis method wherein the channel member included in the separation membrane spiral wound element includes both a supply side channel material and a transmission side channel material.

That is, the channel member includes a supply-side channel member and a permeate-side channel member, and the supply-side channel member may be expressed as a feed spacer, and the transmission-side channel member may be expressed as a tricot.

In an exemplary embodiment of the present specification, the separation membrane spiral wound element may include a separation membrane; Supply spacer; And a separation membrane leaf including a permeable spacer, wherein the separation membrane leaf is wound around a center tube, and the gap between the flow path members is a gap between the separator and a supply spacer or a gap between the separator and the transmission spacer. The interval may mean the shortest interval.

In the exemplary embodiment of the present specification, the step of analyzing the spacing between the channel members included in the separation membrane spiral wound element is to analyze whether the spacing between the channel members is constant. When the distance between the flow path members is constant, it means that the shortest distance between the separator and the supply spacer is the same at any point, or that the distance between the separator and the permeable spacer is the same at any point.

Element quality can be objectively classified by visually and quantitatively analyzing whether the interval between the channel members is constant.

In one embodiment of the present specification, the separation membrane spiral wound element is a reverse osmosis membrane spiral wound element.

That is, the separation membrane included in the separation membrane spiral wound element may be a reverse osmosis membrane.

In the present specification, the configuration and manufacturing method of the separation membrane spiral wound element are not particularly limited, and general means known in this field may be employed without limitation.

In the exemplary embodiment of the present specification, the standard of the spiral wound membrane element is not particularly limited, and a spiral wound membrane element having a standard generally applied in the art may be analyzed according to the above-described analysis method. For example, elements of household (TW: tap water size) and industrial (4 inches, 8 inches) can be analyzed, depending on the use, for separation of brackish water (BW) or sea water (SW). Separator spiral wound elements can be analyzed.

1 is an image obtained by a computed tomography (CT) apparatus of a separation membrane spiral wound element. The circular hollow portion in the center is the inside of the central tube, and is wound around the central tube with separators and flow path materials. The channel member includes a supply spacer and a transmission spacer.

2 is a pre-processing to analyze the original image captured by the computed tomography apparatus of the spiral wound element of the separation membrane. The width and height of FIG. 2 mean pixel size. The pre-processing means removing noise and parts that are not to be analyzed, such as fiber reinforced plastics (FRP) on the inner and outer diameter side of the core tube from the original cross-sectional image.

3 is an analysis of the cross-sectional image of the spiral wound element of the separation membrane of FIG. 1 by computational image analysis. The horizontal axis and the vertical axis of the drawing mean pixel size, and the color is Euclidean. The distance between the channel members measured by the distance conversion calculation is indicated by the color scale bar on the right.

FIG. 4 is a grayscale image of an image photographed by a computed tomography apparatus of a spiral wound element of a separation membrane, and shows a pre-processing operation for representing the histogram chart of FIG. 5. The width and height of FIG. 4 mean pixel size.

5 is a histogram chart quantitatively analyzing the spacing between the channel members included in the spiral wound element of the separation membrane, the horizontal axis grayscale level means the spacing between the channel members, the vertical axis is count, and the interval between the channel members. Means the number of frequencies.

6 is a diagram illustrating a spiral wound element of a separation membrane according to an exemplary embodiment of the present specification. Specifically, the separation membrane spiral wound element includes a central tube 40, a feed spacer 20, a separation membrane 10, a transmission spacer 30, and the like. When the raw water is sent to the spiral wound element of the separation membrane, the raw water is introduced through the supply spacer 20 in the element. One or more separation membranes 10 extend outwardly from the central pipe 40 and are wound around the central pipe 40. The supply spacer 20 forms a passage through which raw water is introduced from the outside, and serves to maintain a gap between one separator 10 and the other separator 10. To this end, the supply spacer 20 is in contact with the one or more separation membranes 10 from the upper and lower sides, and is wound around the central pipe 40. The permeable spacer 30 generally has a structure in the form of a fabric, and serves as a passage for creating a space through which purified water can flow through the separator 10. The central pipe 40 is located at the center of the spiral wound element, and serves as a passage through which filtered water is introduced and discharged. At this time, it is preferable that a pore having a predetermined size is formed outside the central pipe 40 so that the filtered water is introduced, and at least one is preferably formed.

Hereinafter, this In order to describe the specification in detail, it will be described in detail with reference to examples. However, the embodiments according to the present specification may be modified in various forms, and the scope of the present specification is not construed as being limited to the embodiments described below. The embodiments of the present specification are provided to more completely describe the present specification to those of ordinary skill in the art.

Example.

In order to analyze the gap between the channel members of the spiral wound element of the separation membrane spiral wound around the central tube by stacking the supply spacer, the separation membrane, and the permeable spacer, a computerized tomography (CT) device, VTOMEX m300, was used. A cross-sectional image of the spiral wound element of the separation membrane was obtained.

The separation membrane spiral wound element was a BW ES 400 (LG Chemical) having a length of 1,013 mm and a diameter of 8 inches.

The obtained cross-sectional image was subjected to computational image analysis to analyze the spacing between the flow path members included in the spiral wound element of the separation membrane.

Specifically, from the original cross-sectional image obtained as shown in FIG. 1, parts not to be analyzed, such as fiber reinforced plastics (FRP) on the inner and outer diameter side of the core tube, and noise were removed to obtain an image as shown in FIG. 2.

After converting the remaining images to grayscale as shown in FIG. 4, a computational image analysis method using a computational Euclidean distance transform method of a 2-D binary image analysis) and stored as imaged data. The data calculated and imaged in this way are shown in the histogram chart of FIG. 5, so that the distance between the channel members can be visually confirmed quantitatively. According to FIG. 5, it can be seen that the frequency of the interval between the flow path members is 500 μm to 700 μm.

As described above, when the gap between the flow path members was analyzed by the separation membrane spiral wound element analysis method according to the present specification, the inside of the separation membrane spiral wound element could be visually and quantitatively analyzed without the process of disassembling and disassembling the elements.

Comparative example.

When manufacturing the separator spiral wound element, a pressure-sensitive paper (Prescale LLW (Fujifilm)), which reacts when pressure is applied, was cut into dimensions of 1,013 mm in length and 30 mm in width, and sandwiched between each of the supply spacer, the separator, and the permeable spacer. Then, the spiral wound separator element of the same standard as the Example was wound and the gap between the flow path members controlled by the pressure was measured.

After winding, the separation membrane spiral wound element was disassembled through autopsy, and the pressure applied to the pressure sensitive paper was analyzed by extracting the inserted pressure sensitive paper. The analysis result could be obtained.

Since the gap between the flow path members in the spiral wound element of the separation membrane is determined by the pressure during the winding process to manufacture the element, the gap between the flow path members becomes narrow when the pressure is relatively high, and when the pressure is relatively low, the flow path material Since the spacing between them is widened, it was confirmed that the diagram of the flow path member spacing according to the pressure received by the pressure-sensitive paper coincided with the results of the analysis of the gaps between the flow path members according to the embodiment.

10: separator
20: supply spacer
30: transmission spacer
40: central tube

Claims (8)

Obtaining a cross-sectional image of the spiral wound element of the separation membrane by using a computerized tomography (CT) device; And analyzing a gap between the flow path members included in the separator spiral wound element by using a computer image analysis method on the cross-sectional image of the spiral wound membrane element. The method of claim 1, wherein the step of obtaining a cross-sectional image of the separation membrane spiral wound element with the computerized tomography (CT) device comprises: positioning the separation membrane spiral wound element in the computerized tomography device to obtain an X-ray (X-ray) ) Separation membrane spiral wound element analysis method to obtain a cross-sectional image of the separation membrane spiral wound element by photographing. The method according to claim 1, wherein the step of analyzing the gap between the flow path members included in the spiral wound element of the separation membrane, the cross-sectional image of the spiral wound element of the separation membrane is a computer Euclidean distance of a 2-D binary image A separation membrane spiral wound element analysis method that analyzes the spacing between channel members included in the separation membrane spiral wound element by a computational image analysis method using a computational Euclidean distance transform method. The method according to claim 1, wherein the analyzing the gap between the flow path members included in the separator spiral wound element comprises converting the cross-sectional image of the spiral wound membrane element into grayscale, and then converting the two-dimensional binary image (2-D A separation membrane spiral wound element analysis method comprising the step of calculating by computational image analysis using a computational Euclidean distance transform method of binary image) and storing the imaged data. The method of claim 1, wherein the flow path member included in the separation membrane spiral wound element includes both a supply spacer and a transmission spacer. The method as set forth in claim 1, wherein the separation membrane spiral wound element comprises: a separation membrane; Supply spacer; And a separation membrane leaf including a permeable spacer, wherein the separation membrane leaf is wound around a center tube, and the gap between the flow path members is a gap between the separation membrane and the supply spacer or between the separation membrane and the transmission spacer. Phosphorus separation membrane spiral wound element analysis method. The method of claim 1, wherein the analyzing the gap between the flow path members included in the separation membrane spiral wound element comprises analyzing whether the gap between the flow path members is constant. The method of claim 1, wherein the separation membrane spiral wound element is a reverse osmosis membrane spiral wound element.

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