KR102311480B1 - Integral type spacer, water treatment apparatus having same and manufacturing method of spacer - Google Patents

Abstract

The disclosed method for manufacturing a spacer according to the present invention includes a solution preparation step of preparing a hydrophilic polymer solution, a shape realization step of supplying the solution to a spacer support placed on a membrane and casting to implement a spacer shape, and Phase separation of the solution includes a phase separation step of integrating the spacer with the membrane and a drying step of drying the phase-separated spacer. According to this configuration, it is possible to manufacture a high-efficiency water treatment device and a spacer thereof that is easy to manufacture and does not reduce water permeability efficiency.

Description

Integrated spacer, water treatment device having the same, and method of manufacturing the spacer

The present invention relates to an integrated spacer, a water treatment device having the same, and a method for manufacturing the spacer, and by manufacturing a spacer integrated with a membrane using a phase separation method, biofilm contamination inhibition and pressure drop that is easy to manufacture and can improve membrane performance It relates to an integrated spacer for reduction, a water treatment device having the same, and a method for manufacturing the spacer.

In general, in a reverse osmosis water treatment device, biofilms such as bacteria, fungi, algae, etc. existing inside the reaction tank attach growth to the surface of the separation membrane such as a membrane, and finally a biofilm having a thickness of about several tens of micrometers ( biofilm) is formed. As such biofilm formation causes membrane contamination and pressure drop, a technology for increasing turbulence and hydrophilicity has been applied as a technology to prevent this.

The technology for increasing the hydrophilicity induces contaminants not to adhere to the spacer surface by coating various hydrophilic polymers on the surface of the spacer laminated on the membrane to form a hydration layer with water and high density with hydrophilic properties. In addition, as a technology capable of reducing the biofilm, a material having a sterilizing effect such as silver nano and zinc oxide is coated on the surface of the spacer to sterilize bacteria, etc. attached to the surface. In addition, by diversifying the shape of the spacer, an optimal shape for minimizing pressure drop reduction is sometimes applied.

As described above, techniques for reducing general biofilm contamination and pressure drop are representative of the spacer surface modification method or the technology of manufacturing various shapes. However, when the reverse osmosis membrane filter module for water treatment is operated for a long period of time, the surface-modifying material may be detached from the spacer surface, and it is difficult to apply various spacer shapes to the actual module manufacturing.

Accordingly, in recent years, various studies for preventing contamination of the membrane and reducing pressure drop have been continuously conducted regardless of the operating time.

Republic of Korea Patent Application No. 10-2014-0064923 Republic of Korea Patent Application No. 10-2014-0006309

An object of the present invention is to provide an integrated spacer capable of improving the performance and efficiency of a membrane by providing a spacer integrated with the membrane using a phase separation method, and a water treatment device having the same.

Another object of the present invention is to provide a method of manufacturing a spacer for achieving the above object.

A water treatment apparatus according to the present invention for achieving the above object includes a water treatment membrane and a spacer formed of a hydrophilic polymer material and integrally provided with respect to the membrane.

In addition, the spacer is integrated into the membrane by a phase separation method after supplying and casting the hydrophilic polymer material in solution to the spacer support laminated with respect to the membrane, and the spacer support is the spacer support. It can be removed later.

In addition, the hydrophilic polymer material may include PAN (polyacrylonitrile, polyacrylonitrile).

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In addition, the spacer may have a plurality of pores.

A method of manufacturing a spacer according to a preferred embodiment of the present invention includes a solution preparation step of preparing a hydrophilic polymer solution, a shape implementation step of supplying the solution to a spacer support placed on a membrane and casting to implement a spacer shape, Phase-separating the solution from the spacer implemented in a shape, a phase-separating step of integrating the spacer with the membrane, and a drying step of drying the phase-separated spacer.

In addition, the solution may be prepared by dissolving the hydrophilic polymer material in a solvent and then removing the gas.

In addition, the hydrophilic polymer material may include polyacrylonitrile (PAN), and the solvent may include dimethylformamide (DMF).

In addition, in the phase separation step, the spacer having a shape may be immersed in a non-solvent.

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In addition, in the drying step, the solvent remaining in the phase-separated spacer is removed by drying in a vacuum oven for 20 to 30 hours, and a plurality of pores may be formed in the spacer by removing the solvent. .

In addition, the PAN may have a concentration of 15 to 20 wt%, and the DMF may have a concentration of 80 to 90 wt%.

In addition, in the shape implementation step, the thickness of the spacer may be set to 250 to 1000 μm, and casting may be performed at a speed of 5 to 15 mm/s.

In the spacer according to a preferred embodiment of the present invention, a solution preparation step of preparing a hydrophilic polymer solution, a shape implementation step of supplying the solution to a spacer support placed on a membrane and casting to implement a spacer shape, a shape implemented Phase separation of the solution from the spacer, a phase separation step of integrating the spacer with the membrane, and a drying step of drying the phase-separated spacer.

According to the present invention having the above configuration, first, by manufacturing the spacer integral with the membrane in various shapes and sizes, the manufacturing ability is excellent as the spacer can be manufactured at the same time as the film formation.

Second, since the spacer has its own pores and has high hydrophilicity, it is possible to minimize the portion covering the membrane, thereby contributing to efficiency improvement such as improvement of water permeability, minimization of pressure drop, and reduction of fouling.

Third, it is possible to optimize the porosity and pore size of the spacer to minimize pressure drop and induce turbulence, so that high efficiency can be maintained even for long-term operation.

Fourth, various additives can be added during the manufacture of the spacer, thereby maximizing the contamination reduction effect of the membrane.

1 is a cross-sectional view schematically showing a water treatment apparatus having a spacer according to a preferred embodiment of the present invention.
FIG. 2 is a flowchart schematically illustrating a method of manufacturing the spacer shown in FIG. 1 .
FIG. 3 is a plan view schematically illustrating a spacer support for manufacturing the spacer shown in FIG. 1 .
FIG. 4 is a view schematically illustrating a method of casting a spacer using the spacer support shown in FIG. 3 .
FIG. 5 is a schematic enlarged view of the main part of the spacer manufactured by FIG. 4 . and,
FIG. 6 is a schematic enlarged view of a fiber of the spacer shown in FIG. 5 .

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. However, the spirit of the present invention is not limited to such embodiments, and the spirit of the present invention may be proposed differently by adding, changing, and deleting components constituting the embodiment, but this is also included in the scope of the present invention. will become

Referring to FIG. 1 , it is a cross-sectional view schematically illustrating a water treatment apparatus 1 according to a preferred embodiment of the present invention. As shown in FIG. 1 , the water treatment device 1 includes a membrane 10 and a spacer 20 .

For reference, the water treatment apparatus 1 described in the present invention is illustrated and exemplified as being applied to reverse osmosis membrane water treatment such as seawater desalination equipment.

The membrane 10 is a membrane for water treatment and has a multilayer structure as shown in FIG. 1 . More specifically, the membrane 10 includes a first layer 11 including a non-woven fabric, a second layer 12 that is laminated on the first layer 11 to support it, and a second layer 12 . A third layer 13 that is a stacked selective layer may be included. The multi-layer structure of the membrane 10 is not limited to that illustrated in FIG. 1 , and may be variously changed according to water treatment conditions.

The spacer 20 is formed of a hydrophilic polymer material, and is provided integrally with the membrane 10 . The spacers 20 may be integrally provided to be stacked on the third layer 13 of the membrane 10 having a multilayer structure as shown in FIG. 1 . The spacer 20 is manufactured by the method 100 for manufacturing the spacer 20 as shown in FIG. 2 .

Referring to FIG. 2 , the method 100 for manufacturing the spacer 20 includes a solution preparation step 110 , a shape realization step 120 , a phase separation step 130 , and a drying step 140 .

In the solution preparation step 110 , a hydrophilic polymer solution L (see FIG. 4 ) is prepared. The solution (L) is prepared by dissolving the polymer PAN (polyacrylonitrile), which is a porous material, in a solvent containing DMF (dimethylformamide), and then removing the gas. At this time, the polymer PAN of the solution (L) has a concentration of 15 to 20 wt%, and the DMF has a concentration of 80 to 90 wt%, so that the viscosity is high to delay the phase separation rate in the phase separation step 130 to be described later. good. More specifically, the PAN of the solution (L) has a high concentration of 15 to 20 wt%, thereby increasing the mechanical strength, and can withstand a high pressure of about 60 bar.

In this embodiment, PAN of the solution (L) has a concentration of 15 wt%, DMF is exemplified as having a concentration of 85 wt%, but is not limited thereto. In addition, the additive material of the solution (L) is variously variable, so it is advantageous for the manufacture of the spacer 20 of various conditions that can respond to various conditions.

The shape implementation step 120 implements the shape of the spacer 20 by supplying the solution L to the spacer support 21 (refer to FIG. 3 ) placed on the membrane 10 and performing casting.

Here, the spacer support 21 is a type of mold to which the solution L is supplied, and it is possible to cast various spacers 20 according to the shape and size of the spacer support 21 . The spacer support 21 is, as shown in FIG. 3, a plurality of pore frames 21a of a hexagonal shape having a predetermined area, a plurality of connecting frames 21b and a pore frame ( By having the empty space 21c between 21a) and the connecting frame 21b, it can have a formwork shape corresponding to a kind of honeycomb.

However, the spacer support 21 is not limited to the shape shown in FIG. 3 , and the spacer frame 21a may be provided to have various shapes and sizes, such as a circle, a square, etc., rather than a hexagonal shape. It is preferable that the spacer support 21 has a shape that can minimize the area in which the spacer 20 to be manufactured is in contact with the surface of the membrane 10 .

The spacer support 21 as shown in FIG. 3 is laminated on the membrane 10 as shown in FIG. 4 , and the solution L is supplied to the spacer support 21 . At this time, the casting machine 22 having a casting knife casts the solution L to implement the shape of the spacer 20 .

Referring to FIG. 5 , an enlarged view of the main part of the spacer 20 cast using the spacer support 21 is shown. As shown in FIG. 5 , a plurality of voids 20a open to correspond to the void frame 21a of the spacer support 21 are formed, and a connection frame 21b of the spacer support 21 is formed between the plurality of voids 20a. A connection hole 20b corresponding to . Also, a partition wall 21c corresponding to the empty space 21c of the spacer support 21 is provided between the plurality of voids 20a. Therefore, the spacer 20 has a honeycomb shape having a plurality of voids 20a.

For reference, when casting using the spacer support 21, the thickness of the spacer 20 to be cast is set to 250 to 1000 μm, and it is preferable to cast at a speed of 5 to 15 mm/s. In this embodiment, after setting to a thickness of 300 μm, it is exemplified that the spacer 20 is cast using the casting machine 22 at a speed of 10 mm/s.

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In the phase separation step 130 , the solution L is phase-separated from the spacer 20 having a shape, and the spacer 20 is integrated with the membrane 10 . In the phase separation step 130, phase separation is achieved by immersing the shaped spacer 20 in a non-solvent.

As the spacer 20 is integrated with the membrane 10 in this way, the cover area covering the membrane 10 can be minimized. Therefore, it is possible to prevent a decrease in the water permeability of the membrane 10 due to the spacer 20 , and it is possible to secure high hydrophilicity due to the material properties of the spacer 20 . In addition, compared to the conventional spacer structure coated with a hydrophobic material, it is possible to improve problems such as contaminants such as organic matter being caught in the pores 20a in the integrated spacer 20 having hydrophilic properties.

In the drying step 140 , the phase-separated spacer 20 is dried. This drying step 140 is dried in a vacuum oven for 20 to 30 hours to remove the solvent containing DMF remaining in the phase-separated spacer 20 . Accordingly, pores 24 (see FIG. 6 ) are formed in the space from which the solvent is removed in the spacer 20 .

The spacer 20 manufactured through the method 100 for manufacturing the spacer as described above may have a shape as shown in FIG. 5 , and the shape of the spacer 20 may be deformed according to the shape of the spacer support 21 , which is a formwork. do. In addition, as shown in an enlarged view of FIG. 6 , the spacer 20 includes a plurality of fibers 23 . Here, since the plurality of pores 24 are formed in the plurality of fibers 23 forming the spacer 20 , the spacer 20 can realize the effect of reducing water permeation reduction through its own pores 24 . For reference, the size of the pores 24 of the spacer 20 is not huge, and by providing a plurality of microscopically, the effect of reducing the water permeability is excellent.

Referring to Table 1 below, images taken with a scanning electron microscope (SEM) for the generation of pores according to sample types are compared.

sample 1 sample 2 sample 3

Here, Sample 1 is a Pristine PA surface, which is the surface of a commercial reverse osmosis membrane, and corresponds to the membrane 10 . Sample 2 is the PAN surface when a flat membrane is fabricated with general PAN. In addition, sample 3 is a sample prepared by attaching a PAN material to a spacer on a commercial reverse osmosis membrane, and is a PAN/PA surface corresponding to the spacer 20 integrally provided in the membrane 10 according to an embodiment of the present invention. For reference, the image of Table 1 shows the same shape as in Table 1 on the surface of the sample in the form of a flat film, but also on the surface of the sample in the form of a fiber. As a result of observing these samples with a scanning electron microscope (SEM), in the case of sample 1 (Pristine PA), it was possible to confirm a dense surface with hardly visible pores, and in the case of sample 2 (PAN), pores with a size of about 100 to 200 μm were observed. distribution can be observed. In addition, it can be seen that the surface of sample 3 (PAN/PA) has pores having a size of approximately 500 μm, so that the pores are significantly larger than that of sample 2.

The samples shown in Table 1 have the component characteristics (EDS) shown in Table 2 below.

sample 1
(Pristine PA) sample 2
(PAN) sample 3
(PAN/PA) Element Weight % Atomic % Element Weight % Atomic % Element Weight % Atomic % C 70.03 78.04 C 69.02 72.33 C 69.15 75.08 N 7.25 6.92 N 29.45 26.46 N 20.93 19.49 O 12.73 10.65 O 1.54 1.21 O 3.41 2.78

That is, as shown in Table 2, in Sample 3, it can be confirmed that the nitrogen content is greater than in Sample 1 (Pristine PA) by integrally casting PAN made of carbon and nitrogen to PA.

As described above, the spacer 20 according to the present embodiment has its own water permeation performance separately from the membrane 10 . The porosity and pore size of the porous spacer 20 for minimizing pressure drop and inducing turbulence can be optimized by the own pores 24 of the spacer 20 . In this case, the size of the plurality of pores 24 is variable according to the performance condition of the membrane 10 .

On the other hand, in this embodiment, the type of the hydrophilic polymer solution (L) for manufacturing the spacer 20 is not limited, and various additives such as _{MOF, GO and silicon dioxide (SiO 2 ), which are porous materials, are added.} The effect of reducing the pollution of (10) can be maximized.

As described above, by integrating the spacer 20 with the membrane 10 with a solution L containing a high hydrophilic polymer material, the spacer 20 is detached from the membrane 10 even when water treatment is operated for a long time due to the high hydrophilicity. doesn't happen In addition, by providing the spacer 20 by a casting method using the spacer support 21 , the spacer 20 may be manufactured in various shapes and materials.

Therefore, the spacer 20 according to the present invention does not cause problems such as contamination of the membrane 10 and pressure drop, and the spacer 20 can be manufactured at the same time as the film formation. In addition, since the spacer 20 can minimize the area covering the surface of the membrane 10, it is possible to improve water permeability and prevent contaminants from being caught in the pores 20a, which is effective in minimizing pressure increase and reducing fouling. am. In addition, since the spacer 20 has its own pores 24, it is effective to reduce the decrease in water permeability.

As described above, although described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the following claims. You will understand that it can be done.

1: water treatment device
10: membrane
20: spacer
21: spacer support
22: casting machine
23: Fiber
24: Qigong
L: solution

Claims (15)

membranes for water treatment; and
a spacer formed of a hydrophilic polymer material and integrally provided with respect to the membrane;
includes,
The membrane is provided in a multi-layer structure,
The spacer is integrally provided so as to be laminated on one side of the membrane, and is cast by a hydrophilic polymer solution obtained by putting the hydrophilic polymer material in a solvent to form and implement, and phase separation of the hydrophilic polymer solution from the formed spacer After the spacer is dried,
The solvent is removed from the spacer to form a plurality of pores in the spacer,
The spacer is integrated into the membrane by a phase separation method after casting the hydrophilic polymer material in solution and supplying it to a spacer support laminated to the membrane,
the spacer support is removed after the spacer is cast,
The hydrophilic polymer material includes PAN (polyacrylonitrile), the solvent includes DMF (dimethylformamide, dimethylformamide),
PAN of the hydrophilic polymer solution has a concentration of 10 to 20 wt%, DMF of the hydrophilic polymer solution has a concentration of 80 to 90 wt%,
The spacer support,
a plurality of void frames of a predetermined shape;
a plurality of connecting frames interconnecting the plurality of void frames; and
A water treatment device having an empty space between the plurality of connecting frames and the plurality of void frames. delete delete delete delete delete A solution preparation step of preparing a hydrophilic polymer solution;
a shape implementation step of supplying the solution to a spacer support placed on a membrane and casting the solution to implement a spacer shape;
a phase separation step of phase-separating the solution from the spacer implemented in a shape and integrating the spacer with the membrane; and
a drying step of drying the phase-separated spacer;
It is integrally formed on one side of the membrane provided in a multi-layer structure, including
The solution is prepared by removing the gas after putting the hydrophilic polymer material in a solvent to form a solution,
The drying step removes the solvent remaining in the phase-separated spacer,
A plurality of pores are formed in the spacer by the removal of the solvent,
The hydrophilic polymer material includes PAN (polyacrylonitrile), the solvent includes DMF (dimethylformamide, dimethylformamide),
PAN of the hydrophilic polymer solution has a concentration of 10 to 20 wt%, DMF of the hydrophilic polymer solution has a concentration of 80 to 90 wt%,
The spacer support,
a plurality of void frames of a predetermined shape;
a plurality of connecting frames interconnecting the plurality of void frames; and
A method of manufacturing a spacer having an empty space between the plurality of connecting frames and the plurality of void frames. delete delete delete 8. The method of claim 7,
The phase separation step is a method of manufacturing a spacer by immersing the formed spacer in a non-solvent. 8. The method of claim 7,
The drying step is a method of manufacturing a spacer that is dried in a vacuum oven for 20 to 30 hours. delete 8. The method of claim 7,
The shape implementation step is,
A method of manufacturing a spacer by setting the thickness of the spacer to 250 to 1000 μm and casting at a speed of 5 to 15 mm/s. A spacer prepared according to any one of claims 7, 11, 12, and 14.

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