Filtration membrane unit

Abstract

Provided is a filtration membrane unit capable of preventing the concentrated generation of dirt at a prescribed part of a filtration membrane to improve the purification effect, and capable of reducing the cleaning frequency to prolong the operation time. A filtration membrane unit (1) in which a plurality of membrane modules (2) are laminated and arranged, each membrane module (2) comprising: filtration membranes (3a, 3b) that are configured from a pair of sheet-like members, have a gap (S) formed between the pair of sheet-like members, and introduce purified water obtained by filtering water to be purified into the gap (S); and a nozzle section (6) that sucks the purified water introduced into the gap section (S) and discharges the purified water to the outside, the nozzle section (6) having: a suction port (6a) that is formed of an elongated groove that opens along the edge sections of the filtration membranes (3a, 3b) toward the gap section (S) and is capable of suctioning the purified water in the gap section (S); and a lead-out port (6b) which leads the purified water sucked from the suction port (6a) to the outside of the membrane module (2).

Description

Technical Field

[0001] The present invention relates to a filtration membrane unit formed by stacking a plurality of membrane modules having filtration membranes and nozzles. Background Art

[0002] As a purification technology for filtering sludge to obtain purified water, a filtration membrane unit having a membrane module called a membrane separation activated sludge process (MBR) can be cited. The membrane module (particularly a flat membrane type module) used in the conventional filtration membrane unit is configured to have sheet-shaped filtration membranes arranged opposite to each other, a support body sandwiched between the filtration membranes, and a nozzle portion formed at a predetermined position of the filtration membrane, as disclosed in Patent Document 1, and the purified water filtered by the filtration membrane is sucked by the nozzle portion and discharged to the outside.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2014 / 010554 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, since the nozzle of the conventional membrane module is formed on a part of the outer peripheral edge of the filter membrane, the flow rate of purified water near the nozzle is significantly higher than that of other parts, and there is a problem that dirt (clogging caused by the adhesion of sludge substances) is concentrated near the nozzle. If dirt is concentrated in a part, the purification effect of the entire filter membrane is reduced, and the cleaning frequency of the filter membrane is increased, resulting in a reduction in operating time.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a filtration membrane unit that can prevent the concentrated generation of fouling at a predetermined portion of the filtration membrane to enhance the purification effect and that can reduce the cleaning frequency to extend the operating time.

[0009] Means for solving problems

[0010] The invention described in technical solution 1 is a filtration membrane unit, which is formed by stacking a plurality of membrane modules, and the membrane module comprises: a filtration membrane, which is composed of a pair of sheet-like parts that can capture impurities contained in the purified water and filter it, and the filtration membrane forms a gap between the pair of sheet-like parts, and the purified water obtained by filtering the purified water is introduced into the gap; and a nozzle part, which sucks the purified water introduced into the gap and discharges it to the outside, characterized in that the nozzle part comprises: a suction port, which is composed of a long groove that opens to the gap along the edge of the filtration membrane and can suck the purified water in the gap; and a discharge port, which discharges the purified water sucked from the suction port to the outside of the membrane module.

[0011] The invention described in claim 2 is characterized in that, in the filtration membrane unit described in claim 1 , the nozzle portion is formed in a holding portion that holds the pair of filtration membranes facing each other.

[0012] The invention described in claim 3 is characterized in that, in the filtration membrane unit described in claim 2 , the filtration membrane is formed in a rectangular shape in a plan view, and a pair of opposing side edges are respectively held by the holding portion.

[0013] The invention described in claim 4 is the filtration membrane unit described in claim 1, wherein the membrane module contains a porous member in the gap portion.

[0014] The invention described in claim 5 is characterized in that, in the filtration membrane unit described in claim 1 , the filtration membrane unit includes a bubble ejection portion that ejects bubbles toward the membrane module.

[0015] Effects of the Invention

[0016] According to the invention described in technical solution 1, the nozzle portion comprises: a suction port, which is composed of a long groove that opens toward the gap portion along the edge of the filter membrane and can suck purified water from the gap portion; and a discharge port, which discharges the purified water sucked from the suction port to the outside of the membrane module, thereby preventing the concentration of dirt at a specified position of the filter membrane and improving the purification effect, and reducing the cleaning frequency and extending the operating time.

[0017] According to the invention described in claim 2, the nozzle portion is formed in the holding portion that holds the pair of filter membranes facing each other. Therefore, the nozzle portion can be formed by the holding portion, and the suction port and the outlet of the nozzle portion can be easily formed.

[0018] According to the invention described in technical solution 3, the filter membrane is formed into a rectangular shape when viewed from above, and a pair of opposing side edges are respectively held by holding parts, so the length direction dimension of the suction port formed in the holding part can be set larger, which can further improve the dirt suppression effect.

[0019] According to the invention described in claim 4, since the porous member is accommodated in the gap portion of the membrane module, the gap portion can be ensured to have a desired separation size and purified water can be introduced into the gap portion in a good manner.

[0020] According to the invention described in claim 5, since the air bubble ejecting section ejects air bubbles toward the membrane module, the sludge substances attached to the filtration membrane can be easily removed by ejecting air bubbles. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a perspective view showing the appearance of a filtration membrane unit according to an embodiment of the present invention.

[0022] Figure 2 This is a perspective view showing the appearance of the lower part and the back side of the filtration membrane unit.

[0023] Figure 3 1 is a three-view diagram showing a stacked unit of the filtration membrane unit.

[0024] Figure 4 1 and 2 are three views showing membrane modules constituting the stacking unit.

[0025] Figure 5 It is a perspective view showing the nozzle portion (delivery outlet) of the membrane module.

[0026] Figure 6 It is a perspective view showing a holding portion (first holding portion) in which a nozzle (suction port and lead-out port) is formed in the membrane module.

[0027] Figure 7 is a schematic diagram showing a cross section of the membrane module, (a) is Figure 4 AA line section view, (b) is Figure 4 BB line cross-sectional view.

[0028] Figure 8 is a schematic cross-sectional view showing the stacking structure of the stacking unit ( Figure 3 CC line cross-sectional view).

[0029] Fig. 9 It is a perspective view showing the integrated structure of the stacking unit.

[0030] Fig.10 This is an external view showing a membrane module according to another embodiment of the present invention.

[0031] Fig.11 This is an external view showing a membrane module according to another embodiment of the present invention. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0033] The filtration membrane unit 1 of this embodiment is installed in a purification tank containing water to be purified containing sludge and can filter and purify the water to be purified. Figures 1 to 8 As shown in FIG. 1 , a plurality of stacking units M are provided inside a box-shaped frame F, and each stacking unit M is as shown in FIG. Figure 3 , Fig. 9 As shown, a plurality of membrane modules 2 are stacked and integrated.

[0034] The membrane module 2 comprises a filtration membrane (3a, 3b), a first holding portion 4, a second holding portion 5, and a nozzle portion 6. The filtration membrane (3a, 3b) is composed of a pair of sheet-like components that can capture impurities such as sludge contained in the purified water and filter them. Figure 4 As shown, it is formed in a rectangular shape in a plan view, and a pair of opposing side edges are held by a first holding portion 4 and a second holding portion 5, respectively.

[0035] The filter membrane (3a, 3b) is composed of, for example, a structure having chemical fibers (such as polypropylene, acrylic acid, aromatic polyamide resin or polyethylene terephthalate). Specific materials include polysulfone (PSF), polyvinylidene fluoride (PVDF), polyether sulfone (PES), polyimide (PI), polyvinyl chloride (PVC), cellulose acetate (CA), etc.

[0036] The filter membranes (3a, 3b) of this embodiment form a gap S between a pair of sheet-like members, and purified water obtained by filtering the water to be purified is introduced into the gap S. That is, the filter membrane 3a and the filter membrane 3b are separated by a predetermined size and arranged opposite to each other, and the gap S is formed between these filter membranes 3a and 3b, whereby the water to be purified is filtered in the process of passing through each filter membrane (3a, 3b) and reaching the gap S, and the purified water is introduced into the gap S.

[0037] In addition, a porous member W is accommodated in the gap S of the filter membrane (3a, 3b), and the gap S can be maintained even when a negative pressure is applied. Examples of the material of the porous member W include polyvinyl alcohol (PVA), ethylene vinyl acetate (EVA), polypropylene (PP), and polyethylene (PE). In addition, a mesh member may be accommodated in the gap S instead of the porous member W or together with the porous member W.

[0038] like Figure 4As shown in FIG. 1 , the first holding portion 4 and the second holding portion 5 are composed of long strip-shaped members for holding a pair of filter membranes (3a, 3b) facing each other, and a welding surface D is formed for welding the edges of the filter membranes (3a, 3b). Figure 7 As shown, the side edges of each filter membrane (3a, 3b) are supported by being welded (or bonded) to the welding surfaces D of the first holding part 4 and the second holding part 5 by ultrasonic welding, hot plate welding, etc., and a gap S is formed therebetween.

[0039] And, if Figure 4 As shown in the figure, the first holding part 4 supports one side edge portion (the left side edge portion in the figure) of the filter membrane (3a, 3b) at its welding surface D, and the second holding part 5 supports one side edge portion (the right side edge portion in the figure) of the filter membrane (3a, 3b) at its welding surface D, thereby supporting the filter membrane (3a, 3b) in an opposed state. In addition, the upper and lower edges of the filter membrane (3a, 3b) are sealed by welding (or bonding) to each other by ultrasonic welding, hot plate welding, etc.

[0040] In addition, as the material of the first retaining part 4 and the second retaining part 5, thermoplastic resins such as polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyacetal (POM), ABS, and polyphenylene sulfide (PPS) can be cited.

[0041] Since the nozzle portion 6 sucks the purified water introduced into the gap portion S and discharges it to the outside, in this embodiment, it is composed of a suction port 6a and a discharge port 6b formed in the first holding portion 4. Figure 6 , Figure 7 As shown, the suction port 6a is composed of a long groove that opens toward the gap S along the edge (side edge) of the filter membrane (3a, 3b) and can suck purified water in the gap S, and is formed along the side surface (inner surface) of the first retaining part 4 along the longitudinal direction.

[0042] In addition, the outlet 6b is connected to a part of the suction port 6a (in this embodiment, a position above the filter membranes (3a, 3b)), and as shown in FIG. Figure 5 As shown in FIG. 1 , the outlet 6b is formed to protrude toward the side of the membrane module 2 and is configured to guide the purified water sucked from the suction port 6a to the outside of the membrane module 2. The outlet 6b is connected to the suction pipe portion 7 (see FIG. 1 ) mounted on the frame F. Figure 2 ) is connected, and if negative pressure is generated by a negative pressure generator (not shown) connected to the suction pipe portion 7, negative pressure is generated in the gap portion S through the suction pipe portion 7.

[0043] In this way, the structure is such that by generating a negative pressure in the gap S, the purified water is sucked into the gap S toward the filter membranes (3a, 3b), the purified water filtered in the process of passing through the filter membranes 3a, 3b is introduced into the gap S, and the introduced purified water is discharged to the outside through the nozzle part 6, and then stored outside the filter membrane unit 1 (such as a purified water storage tank provided outside the septic tank) through the suction pipe part 7.

[0044] Moreover, if Figure 3 As shown, by stacking and integrating a plurality of membrane modules 2, a stacking unit M can be obtained. Figure 8 , Fig. 9 As shown, the stacking unit M is formed by stacking a plurality of membrane modules 2, overlapping the first holding portion 4 and the second holding portion 5 of adjacent membrane modules 2, and stacking metal plates H at both ends and inserting a metal shaft L therethrough to prevent it from coming off, thereby integrating the membrane modules.

[0045] Furthermore, the first holding portion 4 and the second holding portion 5 of the adjacent membrane modules 2 are configured so that the filtration membranes (3a, 3b) of the adjacent membrane modules 2 are separated by a predetermined size by overlapping. Figure 8 As shown, the first holding portion 4 and the second holding portion 5 of the membrane module 2 of the present embodiment set the width dimension t of the portion (the wide width portion at the end) overlapping with the first holding portion 4 and the second holding portion 5 of the adjacent membrane module 2 according to the separation dimension u (inter-membrane dimension) of the filtration membranes (3a, 3b). Therefore, when a plurality of membrane modules 2 are stacked to form a stacking unit M, the first holding portion 4 and the second holding portion 5 of the adjacent membrane modules 2 overlap and are positioned in a manner to form the separation dimension u (inter-membrane dimension).

[0046] In addition, regarding the stacking unit M of this embodiment, Figure 3 As shown, the outlets 6b of the nozzles 6 in the adjacent membrane modules 2 are formed to protrude at positions staggered in the vertical direction (offset positions). Thus, the outlets 6b can be set to a predetermined size, the flow rate of the purified water discharged from the gap S can be sufficiently ensured, and interference between adjacent outlets 6b can be avoided.

[0047] Here, if Figure 6 As shown, the suction port 6a of this embodiment is composed of a long groove that opens toward the gap S along the edge of the filter membrane (3a, 3b) and can suck the purified water in the gap S. Therefore, the purified water in the gap S can be sucked in the entire area of ​​the side of the filter membrane (3a, 3b), and the flow rate of the sucked purified water can be prevented from being locally increased.

[0048] In addition, if Figure 1 , Figure 2As shown, the filtration membrane unit 1 of this embodiment is provided with a bubble ejection unit 8 at a position lower than the arrangement position of the stack unit M. The bubble ejection unit 8 is composed of a flow pipe capable of ejecting bubbles from a plurality of bubble holes while circulating the supplied air, and can remove sludge substances attached to the filtration membranes (3a, 3b) by ejecting bubbles toward the membrane module 2.

[0049] According to the filtration membrane unit 1 of the present embodiment, the nozzle portion 6 comprises: a suction port 6a which is formed by a long groove which opens toward the gap portion S along the edge of the filtration membrane (3a, 3b) and can suck the purified water in the gap portion S; and a lead-out port 6b which leads the purified water sucked from the suction port 6a to the outside of the membrane module 2, thereby preventing the concentrated generation of dirt at a predetermined position of the filtration membrane (3a, 3b) and improving the purification effect, and reducing the cleaning frequency and extending the operation time.

[0050] In addition, the nozzle portion 6 of the present embodiment is formed in the holding portion (first holding portion 4) that holds the pair of filter membranes (3a, 3b) facing each other, so the nozzle portion 6 can be formed by using the first holding portion 4, and the suction port 6a and the outlet port 6b of the nozzle portion 6 can be easily formed. In addition, the filter membranes (3a, 3b) of the present embodiment are formed in a rectangular shape in a plan view, and the pair of opposing side edges are held by the holding portions (first holding portion 4 and second holding portion 5), respectively, so the length direction dimension of the suction port 6a formed in the first holding portion 4 can be set larger, and the dirt suppression effect can be further improved.

[0051] In addition, the membrane module 2 of the present embodiment has a porous member W accommodated in the gap S, so the gap S can be ensured to have a desired separation size, and purified water can be well introduced into the gap S. In addition, the filtration membrane unit 1 of the present embodiment has a bubble ejection portion 8 that ejects bubbles toward the membrane module 2, so that sludge substances attached to the filtration membranes (3a, 3b) can be easily removed by ejecting bubbles.

[0052] Furthermore, the retaining parts (the first retaining part 4 and the second retaining part 5) overlap when the membrane modules 2 are stacked, and the filter membranes (3a, 3b) of adjacent membrane modules 2 are separated by a specified size. Therefore, there is no need for clamping objects or clamping mechanisms such as spacers, and the filter membranes (3a, 3b) of adjacent membrane modules 2 can be reliably separated by a specified size without increasing the number of components.

[0053] In addition, the retaining parts (the first retaining part 4 and the second retaining part 5) of the present embodiment set the width dimension t of the overlapping portion with the retaining parts (the first retaining part 4 and the second retaining part 5) of the adjacent membrane module 2 according to the separation dimension u of the filter membrane (3a, 3b). Therefore, by changing the width dimension t at the overlapping portion of the retaining parts (the first retaining part 4 and the second retaining part 5), the separation dimension u of the filter membrane (3a, 3b) in the adjacent membrane module 2 can be arbitrarily adjusted.

[0054] The present embodiment has been described above, but the present invention is not limited thereto. Fig.10 As shown in FIG. 1 , the nozzle portion 6 (suction port 6a and guide port 6b) is formed in both the first holding portion 4 and the second holding portion 5. Fig.11 As shown, the outlet 6b of the nozzle portion 6 is formed at the central position of the first holding portion 4 (or the second holding portion 5). In addition, spacers may be installed between adjacent membrane modules 2 to arbitrarily adjust the separation dimension u (inter-membrane dimension) of the filtration membranes (3a, 3b).

[0055] Industrial Applicability

[0056] As long as it is a filtration membrane unit having a nozzle portion as follows, it can also be applied to other methods, wherein the nozzle portion has: a suction port, which is composed of a long groove that opens toward the gap portion along the edge of the filtration membrane and can suck purified water from the gap portion; and a discharge port, which discharges the purified water sucked from the suction port to the outside of the membrane module.

[0057] Description of symbols

[0058] 1: filtration membrane unit; 2: membrane module; 3a, 3b: filtration membrane; 4: first holding part; 5: second holding part; 6: nozzle part; 6a: suction port; 6b: guide port; 7: suction pipe part; 8: bubble ejection part; M: stacking unit; S: gap part; W: porous part; F: frame; D: welding surface.

Claims

1. A filtration membrane unit, which is composed of a plurality of stacked membrane modules, wherein the membrane module has: a filter membrane composed of a pair of sheet members capable of capturing impurities contained in the water to be purified and filtering the impurities, wherein the filter membrane has a gap formed between the pair of sheet members, and purified water obtained by filtering the water to be purified is introduced into the gap; and a nozzle portion that sucks the purified water introduced into the gap portion and discharges it to the outside, It is characterized in that The nozzle portion has: A suction port, which is composed of a long groove that opens toward the gap along the edge of the filtration membrane and can suck the purified water in the gap; as well as A lead-out port is provided for leading the purified water sucked from the suction port to the outside of the membrane module.

2. The filtration membrane unit according to claim 1, characterized in that: The nozzle portion is formed in a holding portion that holds the pair of filter membranes facing each other.

3. The filtration membrane unit according to claim 2, characterized in that: The filter membrane is formed in a rectangular shape in a plan view, and a pair of opposing side edges are respectively held by the holding portion.

4. The filtration membrane unit according to claim 1, characterized in that: The membrane module accommodates a porous member in the gap portion.

5. The filtration membrane unit according to claim 1, characterized in that: The filtration membrane unit includes a bubble ejection portion for ejecting bubbles toward the membrane module.

Images