WO2017039309A1

WO2017039309A1 - Porous hollow fiber membrane

Info

Publication number: WO2017039309A1
Application number: PCT/KR2016/009712
Authority: WO
Inventors: 장재영
Original assignee: 주식회사 퓨어엔비텍
Priority date: 2015-08-31
Filing date: 2016-08-31
Publication date: 2017-03-09

Abstract

A porous hollow fiber membrane according to an embodiment of the present invention includes a first hollow formed in a central portion of a horizontal cross section thereof, and N (N being a natural number of at least 3) second hollows formed so as to be arranged uniformly equidistant from the central portion. N recessed portions for integrally connecting the spaces between the second hollows are formed on the outer peripheral surface of the horizontal cross section.

Description

Porous Hollow Fiber Membrane

The present invention relates to a porous hollow fiber membrane, and more particularly, to a porous hollow fiber membrane formed so that a plurality of holes are formed in the cross section of the hollow fiber and have a petal shape on the outer circumferential surface.

In general, membrane technology uses selective permeability of a polymer material, etc., and is commercialized while being applied to a desalination process in the United States in the 1960s. Unlike the distillation process, the membrane separation process to which the separation membrane is applied does not have a phase change, thereby saving energy and having a relatively simple process, so that the space occupied by the device is small. Therefore, the separator is widely applied to the reverse osmosis (RO) separation process, ultrafiltration (UF), microfiltration (MF) and nanofiltration (NF) separation process.

Generally, membranes have various shapes such as spiral wound, tubular, hollow fiber, plate and frame, among which hollow fiber has a diameter of 0.2 ~ 2mm Since the shape of the hollow tube, the area ratio per unit volume of the hollow yarn has the advantage of obtaining high productivity compared to the spiral wound, tubular, and plate-shaped.

In particular, recently, a hollow fiber membrane having a unique structure has been developed compared to a commercially available hollow fiber membrane, and Inge of Germany has seven independent capillaries in rigid single fibers having a circular outer circumferential surface. Formed porous membrane (Multibore® membrane) was commercialized. Since the hollow fiber membrane is applied to the ultrafiltration process for water treatment, the separation performance is superior to that of a conventional single-bore hollow fiber membrane in which only one capillary (hollow) is formed in the conventional short fibers, and has excellent mechanical properties and chemical stability. And it is known that the membrane fouling (fouling) effect, such as excellent, but there is still room for improvement in order to maximize the permeation performance, filtration efficiency and membrane fouling prevention performance.

Accordingly, the present inventors have conducted a study on the hollow fiber membrane for water treatment having a new structure, and have formed a channel having a plurality of holes (multi-bore, hollow) in the short fibers constituting the hollow fiber, but the holes (multi- When the outer circumferential surface of the short fibers including bore, hollow) is designed in the shape of petals with a pattern of concave and convex portions not circular, the outer circumferential surface of the short fibers increases the filling density and specific surface area compared to the circular shape, and thus the filtration efficiency is increased. The present invention has been made in view of the fact that the permeation performance can be further improved, and the membrane fouling prevention performance can be greatly improved.

An object of the present invention is to increase the filling density and specific surface area to improve the filtration efficiency and permeability, as well as to prevent membrane fouling, and to form a plurality of hollows (holes) in the short fibers forming hollow fibers, It is to provide a porous hollow fiber membrane formed in the shape of a petal of the concave portion and the convex portion repeated pattern on the outer peripheral surface of the hollow fiber short fiber comprising.

Porous hollow fiber membrane according to an embodiment of the present invention, the first hollow is formed in the center of the cross-section, is arranged so as to uniformly radiate with respect to the center to form N (N is a natural number of 3 or more) second hollows The outer peripheral surface of the cross section is formed with N concave portions for integrally connecting between the second hollow and the second hollow.

Further, when the diameter is larger than the first hollow, the concentric circle of the first hollow is defined as the first virtual circle, the diameter is larger than the second hollow, and the concentric circle of the second hollow is defined as the second virtual circle, The second virtual circle is preferably formed to circumscribe the first virtual circle.

In addition, the first virtual circle radius is formed to the same size as the second virtual circle radius.

In addition, the first virtual circle radius may be larger than the second virtual circle radius.

In addition, the first virtual circle radius is formed smaller than the second virtual circle radius.

In addition, the porous hollow fiber membrane is made of polyethylene (PE) resin, polypropylene (PP) resin, ethylene chloro trifluoro ethylene resin (ECTFE), polyvinyl chloride (PVC) resin, polysulfone resin, polyether sulfone At least one selected from the group consisting of resins, sulfonated polysulfone resins, polyvinylidene fluoride (PVDF) resins, polyacrylonitrile (PAN) resins, polyimide resins, polyamideimide resins and polyetherimides is suitable. .

In addition, the porous hollow fiber membrane is preferably prepared by conventional non-solvent-induced phase transition (NIPS) or heat-induced phase transition (TIPS).

In addition, the above-described porous hollow fiber membrane is preferably applied to the microfiltration membrane, the ultrafiltration membrane, the degassing membrane, and the pervaporation membrane.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in this specification and claims should not be interpreted in a conventional, lexical sense, and the inventors will appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that it can.

Porous hollow fiber membranes according to an embodiment of the present invention, as compared to the conventional mono- or porous hollow fiber membranes by increasing the mechanical strength of the membrane or increase the packing density and specific surface area not only improves the filtration efficiency, permeation performance, but also prevents membrane fouling. It is excellent in effect and can be applied to microfiltration and ultrafiltration separation process for water treatment.

In addition, there is an effect to provide a porous hollow fiber membrane formed of petals of the concave portion and the convex portion repeated pattern on the outer peripheral surface of the hollow fiber short fibers.

In addition, since the distance between the second hollow and the convex portion is constant, there is an effect of providing a multi-fiber membrane module having a uniform permeability and uniform reliability of the product compared to the conventional hollow fiber membrane.

In addition, since the distance between the second hollow and the convex portion is constant, there is an effect that the bending strength and the mechanical strength are improved compared to the conventional circular.

1 is a perspective view of a porous hollow fiber membrane according to an embodiment of the present invention.

2 is an exemplary cross-sectional view of the first virtual circle diameter and the second virtual circle diameter of the porous hollow fiber membrane according to an embodiment of the present invention.

3 is an exemplary view showing the form of FIG.

Figure 4 is an exemplary cross-sectional view of the first virtual circle diameter of the porous hollow fiber membrane is formed larger than the second virtual circle diameter in accordance with an embodiment of the present invention.

5 is an exemplary view showing the form of FIG.

6 is a cross-sectional view illustrating a first virtual circle diameter of the porous hollow fiber membrane smaller than the second virtual circle diameter in accordance with an embodiment of the present invention.

7 is an exemplary view showing the form of FIG.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. In the present specification, in adding reference numerals to the components of each drawing, it should be noted that the same components as possible, even if displayed on different drawings have the same number as possible. In addition, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. In addition, in describing the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a perspective view of a porous hollow fiber membrane according to an embodiment of the present invention, Figure 2 is a cross section in which the first virtual circle diameter and the second virtual circle diameter of the porous hollow fiber membrane according to an embodiment of the present invention are the same 3 is an exemplary view showing the form of Figure 2, Figure 4 is a cross-sectional view of the first virtual circle diameter of the porous hollow fiber according to an embodiment of the present invention is formed larger than the second virtual circle diameter 5 is an exemplary view showing a form of FIG. 4, FIG. 6 is a cross-sectional view illustrating a first virtual circle diameter of the porous hollow fiber membrane smaller than the second virtual circle diameter according to an embodiment of the present invention. 7 is an exemplary view showing the form of FIG.

Referring to Figures 1 to 3, the porous hollow fiber according to an embodiment of the present invention, the first hollow 100 is formed in the center of the cross-section, N is formed so as to uniformly radiate with respect to the center (N is a natural number of 3 or more) two second hollows 200 are formed, and N concave portions for integrally connecting the second hollows 200 and the second hollows 200 are formed on the outer circumferential surface of the cross section. do.

Referring to FIG. 1, the porous hollow fiber membrane 10 is formed in a pillar shape in which a first hollow 100 is formed at a central portion thereof. At this time, the first hollow 100 serves as a passage through which foreign matter or purified material moves. The second hollow 200 is uniformly formed at the back radial position with respect to the center of the first hollow 100. That is, it is appropriate that the second hollow 200 is formed with N (N is a natural number of 3 or more) of the first hollow 100.

Referring to FIGS. 2 and 3, the porous hollow fiber membrane 10 has a first virtual circle 310 and a second hollow formed larger than the first hollow radius a1 based on the center of the first hollow 100. The second virtual circle 330 formed larger than the second hollow radius b1 based on the center of the concentric circle of 200 and the second virtual circle 330 are in contact with the inside from the center of the concentric circle of the first hollow 100. The third virtual circle 350 is included.

Referring to FIG. 2, the first virtual circle 310 is larger than the radius a1 of the first hollow and formed around the concentric circle of the first hollow 100. The first virtual circle 310 is formed such that the second virtual circle 330 is circumscribed. The first virtual circle 310 is disposed at a position where the second hollow 200 is uniformly radiated.

The second virtual circle 330 is larger than the second hollow radius b1 and is formed around the concentric circles of the second hollow 200. The second virtual circle 330 is formed to circumscribe the first virtual circle 310. The second virtual circle 330 is in contact with N (N is a natural number of 3 or more) centering on the first virtual circle 310. That is, the second hollow 200 is formed to be spaced apart from the first hollow 100 in an equal radial shape, and the second hollow 200 is formed of N (N is a natural number of 3 or more).

The third virtual circle 350 is formed to be in contact with the second virtual circle 330 at the center of the first hollow 100. That is, the third virtual circle 350 is formed to have a size of the outer circumferential surface of the porous hollow fiber membrane 10 at the center of the first hollow 100.

Unevenness is formed on the outer circumferential surface of the porous hollow fiber membrane 10. The bending of the unevenness 110 is formed corresponding to the number of the second hollow 200 is arranged. That is, the unevenness 110 may be divided into the concave portion 111 and the convex portion 113. Such unevenness 110 is preferably formed in the shape of a petal with respect to the cross section of the porous hollow fiber membrane 10. Porous hollow fiber membrane 10 is improved in bending strength and mechanical strength than the conventional circular. That is, the porous hollow fiber membrane 10 serves to withstand the air injected vertically when installed in the filtration device. Many air pressure is formed on the surface of the porous hollow fiber 10 has the effect of improving the filtration efficiency.

Concave-convex 110 is a convex portion 113 is formed in a portion formed by extending the second hollow 200 in the circumferential direction. In addition, the concave-convex 110 includes a concave portion 111 at a portion connecting the second hollow 200 and the second hollow 200 in the circumferential direction.

The convex portion 113 of the concave-convex 110 is formed to contact the inner side of the third virtual circle 350, and the concave portion 111 of the concave-convex 110 is the second hollow 200 and the second hollow 200. It is formed between. That is, the recess 111 has a space close to the space between the second hollow 200 and the second hollow 200 is formed.

The unevenness 110 is formed on the outer circumferential surface of the porous hollow fiber membrane 10, thereby improving the specific surface area and filtration efficiency. In addition, the concave-convex 110 forms a concave portion 111 on the outer circumferential surface of the porous hollow fiber membrane 10, so that the concave-convex 110 reduces the raw materials used in manufacturing, thereby improving economic efficiency. Further, the unevenness 110 serves to ensure uniform permeability and uniform reliability of the product as compared to the conventional hollow fiber membrane by making the distance between the second hollow 200 and the convex portion 113 constant.

For example, when three second hollows 200 are formed as shown in FIG. 3A, the concave portion 111 is formed to be closer to the first hollow 100. That is, the second hollows 200 are provided. When the three are formed, it can be seen that the concave portion 111 is in contact with the first virtual circle 310. This does not mean that when three second hollows 200 are formed, the concave portion 111 is necessarily formed in contact with the first virtual circle 310. That is, it is revealed that the recess 111 is formed near the first virtual circle 310.

Referring to FIGS. 3B to 3H, the porous hollow fiber membrane 10 is formed such that when the second hollow 200 increases by one, the concave portion 111 moves away from the first hollow 100 direction. That is, when four or more second hollows 200 are formed, it can be seen that the concave portion 111 is far from the first virtual circle 310. That is, the concave portion 111 is formed to be closer to the direction of the third virtual circle 350 while gradually moving away from the vicinity of the first virtual circle 310 when the second hollow 200 increases. That is, the recess 111 is formed near the first virtual circle 310 as shown in FIG. 3A, and the recess 111 is formed near the third virtual circle 350 as shown in FIG. 3H. can confirm. do.

The porous hollow fiber membrane 10 has a radius a2 of the first virtual circle 310 and a radius b2 of the second virtual circle having the same size.

On the other hand, the porous hollow fiber membrane 10 may be made of a hydrophobic polymer including a vinyl polymer and an olefin polymer. As the hydrophobic polymer, polyethylene (PE) resin, polypropylene (PP) resin, ethylene chloro trifluoro ethylene resin (ECTFE), polyvinyl chloride (PVC) resin, polysulfone resin, polyethersulfone resin, sulfonated polysulfone resin And at least one selected from the group consisting of polyvinylidene fluoride (PVDF) resin, polyacrylonitrile (PAN) resin, polyimide resin, polyamideimide resin, and polyetherimide. In particular, fluorine-containing hydrophobic polymers such as polyvinylidene fluoride (PVDF) homopolymers or copolymers thereof are more preferably used in view of chemical stability.

In addition, the porous hollow fiber membrane 10 according to the present invention is obtained by dissolving the above-mentioned hydrophobic polymer in a solvent or a solvent containing a non-solvent or an additive, if necessary, to obtain a spinning solution, the spinning solution and the internal coagulant to the spinning nozzle After discharging, supplying and spinning through a conventional nonsolvent induced phase separation method (NIPS) or thermally induced phase separation method (TIPS) to form a hollow fiber completely phase-transferred by an external coagulant It can be manufactured by.

Second embodiment

Referring to FIG. 4, the porous hollow fiber membrane 10 according to the second exemplary embodiment of the present invention omits the same components as those of the first exemplary embodiment, and the radius a2 of the first virtual circle 310 is set to the first. The case in which the virtual circle 330 is formed larger than the radius b2 will be described in detail.

Unevenness is formed on the outer circumferential surface of the porous hollow fiber membrane 10. The bending of the unevenness 110 is formed corresponding to the number of the second hollow 200 is arranged. That is, the concave-convex 110 may be divided into the concave portion 111 and the convex portion 113 (see FIG. 4).

For example, when six second hollows 200 are formed as shown in FIG. 5A, the recess 111 has a depth of “v” shape in the direction of the first hollow 100.

5A to 5D, the porous hollow fiber membrane 10 is increased by one second hollow 200. When the concave portion 111 is formed one by one between the second hollow 200 and the second hollow 200, the concave portion 111 is formed to move away from the first hollow 100 direction. That is, when seven or more second hollows 200 are formed, it can be seen that the concave portion 111 is far from the first virtual circle 310. That is, the concave portion 111 is formed to be closer to the direction of the third virtual circle 350 while gradually moving away from the vicinity of the first virtual circle 310.

Third embodiment

Referring to FIG. 6, the porous hollow fiber membrane 10 according to the third exemplary embodiment of the present invention omits the same components as those of the first exemplary embodiment, and the radius a2 of the first virtual circle 310 is set to the first. The case in which the virtual circle 330 is formed smaller than the radius b2 will be described in detail.

Filtration efficiency can be increased while reducing the diameter of the porous hollow fiber membrane 10. The porous hollow fiber membrane 10 is formed to have a smaller radius a2 of the first virtual circle 310, and increases the radius b2 of the second virtual circle 330 of the porous hollow fiber membrane 10. That is, by increasing the radius b1 of the second hollow 200 of the surface outer diameter of the porous hollow fiber membrane 10, the filtration efficiency and the packing density may be increased (see FIG. 6 or 7).

Unevenness is formed on the outer circumferential surface of the porous hollow fiber membrane 10. The bending of the unevenness 110 is formed corresponding to the number of the second hollow 200 is arranged. That is, the concave-convex 110 may be divided into the shape of the concave portion 111 and the convex portion 113 (see FIG. 6).

For example, when three second hollows 200 are formed as shown in FIG. 6A, the recess 111 has a depth of “v” shape in the direction of the first hollow 100.

Referring to FIGS. 7A to 7C, the porous hollow fiber membrane 10 is increased by one second hollow 200. In this case, when the recess 111 is formed one by one between the second hollow 200 and the second hollow 200, the recess 111 is formed to be far from the first hollow 100 direction. That is, when four or more second hollows 200 are formed, it can be seen that the concave portion 111 is far from the first virtual circle 310. That is, the concave portion 111 is formed to be closer to the direction of the third virtual circle 350 while gradually moving away from the vicinity of the first virtual circle 310.

Hereinafter, an experimental example in which a porous hollow fiber membrane formed in the shape of a petal having a concave portion and a convex portion on the outer circumferential surface of the hollow fiber short fiber according to an embodiment of the present invention is repeated to evaluate water permeability and mechanical properties. To describe.

Experimental Example

40% by weight of polyvinylidene fluoride resin (weight average molecular weight 300,000 to 320,000), 15% by weight of silica, 30% by weight of dioctylphthalate and dibutyl, using a porous (multibore) nozzle with an outer diameter of the nozzle The composition was discharged at 240 ° C. using a twin screw extruder with a composition of 15% by weight of phthalate. Dioctyl phthalate was used at 30 ° C. as a hollow forming agent, passed through an 80 mm air chamber, and solidified in a 60 ° C. water bath, stretched 50% in a 60 ° C. water bath, and stabilized in a hot air at 120 ° C. The winding speed was adjusted to 15 m / min to prepare a porous hollow fiber membrane having an outer circumferential surface as shown in FIG. 1 in the shape of a petal (outer diameter 4.2 탆, inner diameter 0.8 탆). After immersing the porous hollow fiber membrane having a petal-like outer circumferential surface for 30 minutes in methylene chloride, immersing in 8% by weight of sodium hydroxide solution for 15 minutes, immersion in ethanol for 10 minutes, and glycerine in 3% by weight aqueous solution for 24 hours The water permeability and mechanical properties were evaluated through the treatment, and the results are shown in Table 1.

[Comparative Example]

A porous hollow fiber membrane having a circular outer circumferential surface was prepared in the same manner as in the above experimental example, except that the nozzle had a circular porous diameter (multibore) nozzle, and the water permeability and mechanical properties were evaluated through post-treatment. It was.

Table 1

Sample	Water transmission flux (L / ㎡.hr, 0.1mpa)	Breaking load (N)	Elongation at Break (%)
Experimental Example	3,600	46.9	120
Comparative example	2,100	36.2	80

As shown in Table 1, the porous hollow fiber membrane of the outer circumferential surface prepared from the experimental example according to an embodiment of the present invention is petal-shaped compared to the porous hollow fiber membrane of which the outer circumferential surface prepared from the comparative example is circular. It can be seen that the remarkably increased, which is due to the fact that the outer diameter of the nozzle is petal-shaped, heat transfer is uniformly made during the hollow fiber membrane formation process, the surface area is large.

In addition, in terms of mechanical properties such as maximum breaking load and elongation at break, according to an embodiment of the present invention, the porous hollow fiber membrane having the outer circumferential surface prepared from the experimental example has a petal-shaped porous hollow fiber membrane having the circular outer circumferential surface prepared from the comparative example It can be confirmed that it is much superior to that, this is because the porous hollow fiber membrane having the outer circumferential surface is formed in the bone during the hollow fiber membrane formation process, the orientation is good during stretching, the strength is increased, the pores are uniformly formed and the longitudinal direction is increased. It is interpreted that the bone is formed and the elongation is improved.

Therefore, according to the porous hollow fiber membrane of the present invention, by increasing the packing density and the specific surface area compared to the conventional single-hole or porous hollow fiber membrane, not only the filtration efficiency and permeation performance is improved, but also the membrane fouling prevention effect is excellent, and the fine filtration membrane, It can be applied to the separation process of ultrafiltration membrane, degassing membrane and permeation membrane.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiments are for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various implementations are possible within the scope of the technical idea of the present invention.

Claims

A first hollow is formed at the center of the cross section, and is uniformly radiated with respect to the center to form N (N is a natural number of 3 or more) second hollows.

The hollow hollow fiber membrane of the cross-sectional outer surface is formed with N concave portions for integrally connecting between the second hollow and the second hollow.
The method according to claim 1,

A diameter larger than the first hollow, and defines a concentric circle of the first hollow as a first virtual circle,

When the diameter is larger than the second hollow and the concentric circles of the second hollow are defined as the second virtual circle,

The second virtual circle is a porous hollow fiber membrane formed to circumscribe the first virtual circle.
The method according to claim 2,

The first virtual circle radius is a porous hollow fiber membrane, characterized in that formed in the same size as the second virtual circle radius.
The method according to claim 2,

And the first virtual circle radius is larger than the second virtual circle radius.
The method according to claim 2,

And the first virtual circle radius is smaller than the second virtual circle radius.
The method according to any one of claims 1 to 5,

The porous hollow fiber membrane may be made of polyethylene (PE) resin, polypropylene (PP) resin, ethylene chloro trifluoro ethylene resin (ECTFE), polyvinyl chloride (PVC) resin, polysulfone resin, polyether sulfone resin, At least one member selected from the group consisting of sulfonated polysulfone resin, polyvinylidene fluoride (PVDF) resin, polyacrylonitrile (PAN) resin, polyimide resin, polyamideimide resin and polyetherimide Hollow fiber membrane.
The method according to claim 6,

The porous hollow fiber membrane is a porous hollow fiber membrane, characterized in that produced by the conventional non-solvent induction phase transition method (NIPS) or heat induced phase transition method (TIPS).
The porous hollow fiber membrane according to any one of claims 1 to 5 is applied to a microfiltration membrane, an ultrafiltration membrane, a degassing membrane and a pervaporation membrane.