JPH06198144A - Membrane separator - Google Patents

Abstract

PURPOSE:To prevent an inlet of a raw liq. passage from being plugged even if papery or filiform foreign matter is entwined with the tip of a unit module. CONSTITUTION:This membrane separator 11 is provided with a flat-membrane module 13 to be dipped in the raw liq. in a vessel 12 and an aeration tube 14 for generating a circulating current in the vessel by the discharged bubbles and used to discharge the treated liq. from a permeated liq. recovery tube 23 connected to the module. The adjacent unit modules 15a and 15b of the module are alternately made different in the mounting height to allow the positions of the tip differ from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane separation device for taking out a treatment liquid by immersing a flat membrane module having a separation membrane such as a reverse osmosis membrane, an ultrafiltration membrane or a microfiltration membrane in a stock solution in a container. It is a thing.

[0002]

2. Description of the Related Art As a conventional membrane separator for immersing a flat sheet membrane module in a stock solution in a container, the one described in JP-A-1-29313 proposed by the applicant of the present application is known. As shown in FIG. 7, this conventional membrane separation device includes a unit module 3 having flat membranes 2a and 2b inside a container 1.
The flat membrane module 4 is configured by arranging a plurality of ... At the same height at predetermined intervals, and the treatment liquid recovery pipe 7 is connected to the header pipe 6 connected to the water collection pipe 5 of each unit module 3 to obtain the treatment liquid. The treatment liquid is taken out by the operation of a pump provided in the middle of the recovery pipe 7. The membrane separation device having such a structure can perform membrane separation with low energy by utilizing the water head difference based on the water depth of the undiluted solution, and the filtration operation is repeated intermittently, or aeration air is fed from the aeration pipe 8 to form a membrane surface. It prevents the growth of gel-like substances adhering to, and also prevents the stock solution passage (membrane-to-membrane gap) from being blocked.

[0003]

However, when a paper piece-like or thread-like foreign matter SS is mixed in the stock solution, as shown in FIG. 9, the unit solution 3 flows into the stock solution, that is, corresponds to the inlet port. Paper-like or thread-like foreign matter SS at the lower end of the
Are entangled with each other to block the inlet of the undiluted solution passage 10, and finally the undiluted solution passage 10 is clogged with sludge, which significantly reduces the filtration rate. As a means for solving such a problem, it is conceivable to remove the paper-like or filamentous foreign matter SS in the undiluted solution and then perform membrane separation, but in the case of treatment of wastewater, etc., complete removal of these. Is extremely difficult, and its removal requires a large-scale device and a large amount of driving power, so that it is not a realistic solution. Therefore, the present invention is
It can be filtered with low power, and while maintaining a high filtration rate,
An object of the present invention is to provide a membrane separation device in which the inlet of the stock solution passage is not blocked.

[0004]

The present invention was developed to achieve the above-mentioned object, and has a flat membrane module immersed in the stock solution in a container, and the permeated liquid recovery connected to the flat membrane module. In the membrane separation device for taking out the treatment liquid from the tube, the positions of the tip portions of the unit modules adjacent to each other of the flat membrane module are different.

[0005]

Even if foreign matter SS in the form of paper or thread is entangled at the tip of the unit module, the tips of the adjacent unit modules are not on the same plane because their positions are different, and therefore the foreign matter S entangled at the tip.
Since the Ss are separated from each other, it is possible to secure a gap into which the undiluted solution flows.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a membrane separation device 11 according to an embodiment of the present invention.
3 is an internal perspective view showing the configuration of FIG. This membrane separation device 1
1 includes a flat membrane module 13 inside a container 12, and an aeration pipe 14 is provided below the flat membrane module 13 or in the vicinity thereof.
... are arranged, and the air bubbles sent out from the aeration pipe 14 cause a circulating convection in the stock solution in the container 12 that rises from below the flat membrane module 13 to the above and then descends toward the aeration pipe 14 side. Flat membrane module 1 by the stirring action of
The gel-like material is prevented from adhering to No. 3.

The flat sheet membrane module 13 is composed of a plurality of unit modules 15 ... In this embodiment, the unit modules 15 of the same size are mounted vertically at a predetermined interval d, but they are mutually attached. Adjacent unit module 1
The mounting heights of 5a and 15b are different from each other.

As shown in FIG. 2, the unit module 15a includes the films 17 and 17 on both sides of a spacer 16 formed of a net or the like.
And a permeate chamber 1 formed between both membranes 17,
The upper end of 8 communicates with the upper water collecting pipe 19a, and the lower end of 8 communicates with the lower water collecting pipe 20a.
It is configured so that the stock solution does not enter inside. The unit module 15b has the same structure as the unit module 15a, and the membranes 17 and 17 are stretched on both sides of the spacer 16 to form a permeate chamber 18 therebetween, and the upper end of the permeate chamber 18 is connected to the upper water collecting pipe. 19b, the lower end is connected to the lower water collecting pipe 20b, respectively.

A unit module 15 having such a configuration
When the flat membrane module 13 is constructed by attaching a plurality of a, 15b ..., For the first unit module 15a arranged at a high position, one end of the upper water collecting pipe 19a is the shaft 21 and the other end is the upper header pipe. 22 directly connected to each. Then, one end of the upper header pipe 22 is connected to the permeated liquid recovery pipe 23, and a suction pump 24 is provided in the middle of the permeated liquid recovery pipe 23. The lower water collecting pipe 20a of the first unit module 15a has one end connected to the communication pipe 25,
The other end is connected to the lower header pipe 26 via a rising pipe 27, respectively.

On the other hand, for the second unit module 15b arranged at a low position, one end of the upper water collecting pipe 19b is connected to the shaft 21 and the other end is connected to the upper header pipe 22 through the falling pipe 28. The lower water collecting pipe 20b of the second unit module 15b has one end directly connected to the communication pipe 25 and the other end directly connected to the lower header pipe 26.

In this way, the adjacent first unit modules 1
5a and the water collecting pipes 19a, 19 of the second unit module 15b
b, 20a, 20b to the rising pipe 27 and the falling pipe 2
When connected to the header pipes 22 and 26, the shaft 21 and the like via 8, the heights of the upper ends of the adjacent first unit module 15a and second unit module 15b are different from each other as shown in FIG. The height of the part is also different from the next.

Next, the distance d between the unit modules 15 and the height difference h will be described. Unit modules 15a, 15b
If the interval d is set to be small, the membrane area per unit volume can be made large, but reducing the interval d also narrows the undiluted solution passage 29 through which the undiluted solution flows. Therefore, there is a risk that the undiluted solution passage 29 will be blocked. Increase. Therefore, this interval d is naturally determined by the composition of the liquid to be separated, that is, the composition of the stock liquid, and the operating conditions, but it is desirable to set it to a range of approximately 1 to 10 mm. In addition, adjacent unit modules 15
It is desirable to set the height difference h between a and 15b to be large in consideration of the entanglement of the foreign matter SS described later, but if it is too large, the film area per unit volume becomes small.
It is desirable to set in the range of ≦ h ≦ 10d.

When the stock solution is processed by the membrane separation device 11 having the above-mentioned structure, the suction pump 24 is operated while generating bubbles from the aeration pipe 14. In this way, as shown in FIG. 4, in the present embodiment, the flat sheet membrane module 1
Since the aeration pipe 14 is arranged below the unit 3, a circulating flow that flows upward from below the flat sheet membrane module 13 is generated by the rising bubbles, and the unit liquids adjacent to each other are the unit modules 15a and 1a.
Flows in the interval d of 5b, that is, in the stock solution passage 29. Therefore, the lower end portions of the adjacent unit modules 15a and 15b serve as the inlet of the stock solution passage 29.

When the operation is performed in this state, the treatment liquid that has permeated the membranes 17 of the unit modules 15a, 15b, ... Collects in the upper header pipe 22 from the upper water collecting pipes 19a, 19b through the permeate chamber 18. The collected treatment liquid is discharged through the permeated liquid recovery pipe 23 by the suction action of the suction pump 24. Further, when such an operation is repeated, as shown in FIG. 3, the foreign matter SS in the form of paper or thread mixed in the stock solution is entangled with the lower end portions of the unit modules 15a and 15b and gradually grows.

However, in the membrane separation apparatus 11 according to the present invention, the positions of the lower end portions of the adjacent unit modules 15a and 15b are alternately different, so that the foreign matter SS is entangled in the lower end portions of the unit modules 15a and 15b. However, the gap between the lower ends of the adjacent unit modules 15a and 15b, which function as the inlet of the stock solution passage 29, is not blocked by the adhering foreign matter SS, and the interval at which the stock solution can flow is secured. Therefore, each unit module 15
It is possible to prevent the filtration rates of a and 15b from being significantly reduced.

Further, in the present embodiment, since the unit modules 15a and 15b of the same size are alternately mounted with different heights, not only the height of the lower end portion but also the height of the upper end portion is different. Therefore, as shown in FIG.
When the aeration pipe 14 is arranged at a position distant from the flat sheet membrane module 13 and used in the membrane separation device 11 which circulates the stock solution from the upper side to the lower side in the raw solution passage 29 of the flat sheet membrane module 13, the above-mentioned case Similarly, the effect of preventing the inflow port of the undiluted solution passage 29, that is, the upper end interval of the unit modules 15a and 15b, from being blocked.

Further, even in the membrane separation device 11 which employs a system in which the circulation direction of the stock solution generated in the container 12 is changed at predetermined time intervals, the above-described effect of preventing the blockage of the stock solution passage 29 is exerted. Moreover, by changing the direction of the circulation flow, the foreign matter SS entangled at the outlet end of the stock solution passage 29 can be dropped by the flow of the stock solution.

In summary, the present invention is directed to the flat membrane module 13
Of the unit modules 15 adjacent to each other (portions which become the inlets of the stock solution passages 29) are made different along the flowing direction of the stock solution, in other words, the end sections of the adjacent unit modules are on the same plane. If it is provided in the state not located in
The effect of preventing the inlet of the stock solution passage 29 from being blocked can be exhibited. Therefore, the heights of the tips of the adjacent unit modules 15 may not only be alternately changed but may be changed sequentially.

The flat sheet membrane module 13 is not limited to the one described above. For example, as shown in FIG. 6, a plurality of unit modules 15a ′, 15b ′ ... In which films 17 and 17 are provided on both sides of a spacer 16 are arranged at predetermined intervals d so as to be alternately different from each other by a height h. The unit modules 15a ', 15b', etc. may be arranged and the left and right side portions of the unit modules 15a ', 15b' ... The upper and lower edges of the unit modules 15a ', 15b' ... Are sealed with an adhesive, and
The connecting portion between a ', 15b' ... And the housing 30 is also sealed by a sealing member or a filling member so that the undiluted solution does not enter the inside of the permeate chamber 18 or the like. When the flat sheet membrane module 13 ′ having such a configuration is provided, the permeated liquid recovery pipe 23 is connected to the opening 31 opened at the bottom of the side surface of the housing 30.

A flat sheet membrane module 1 having the above structure
Also in 3 ', adjacent unit modules 15a', 15
Since the heights of the tips of b ′ are alternately different, it is possible to block the inlet of the stock solution passage 29 even if the foreign matter SS in the form of a paper piece or a thread is entangled with each tip like the above-described embodiment. Absent.

In each of the above embodiments, the container 12 is used.
Is an atmosphere open type, but the membrane separation device 1 according to the present invention
The container 12 of 1 may be a closed type that is not open to the atmosphere. When the container 12 of this closed type is provided, the inside of the container 12 is pressurized, so that it is not necessary to provide the suction pump 24 in the permeated liquid recovery pipe 23 of the flat sheet membrane module 13.

[0022]

As described above, according to the present invention, even if the foreign matter SS is entangled with the tip of the unit module, the tip of the adjacent unit module is located at a different position. Will not be blocked by the entangled foreign matter SS. Therefore, a high filtration rate can be maintained for a long time. Further, since it is possible to prevent the inlet of the stock solution passage from being blocked without increasing the interval between the unit modules, the area of the membrane per unit volume does not decrease, and an efficient membrane separation device is provided. You can

[Brief description of drawings]

FIG. 1 is a perspective view of a membrane separation device seen through.

FIG. 2 is a cross-sectional view of a flat sheet membrane module in which the positions of the tip portions are made different by making the heights of adjacent unit modules different.

FIG. 3 is a cross-sectional view of the unit module in a state where the foreign matter SS is entangled with the tip of the unit module.

FIG. 4 is a side view of a membrane separation device in which a stock solution is circulated from below to above the flat membrane module.

FIG. 5 is a side view of the membrane separation device in which the stock solution is circulated from the upper side to the lower side of the flat sheet membrane module.

FIG. 6 is a partially cutaway perspective view of another embodiment of the flat sheet membrane module.

FIG. 7 is an internal perspective view of a conventional membrane separation device.

FIG. 8 is a cross-sectional view of a conventional flat sheet membrane module.

9 is an enlarged cross-sectional view showing a state in which a foreign matter SS is entangled with the tip of the unit module of the flat sheet membrane module shown in FIG.

[Explanation of symbols]

 11 Membrane Separation Device 12 Container 13 Flat Membrane Module 14 Aeration Pipe 15 Unit Module 16 Spacer 17 Membrane 18 Permeate Chamber 19 Upper Water Collection Pipe 20 Lower Water Collection Pipe 22 Upper Header Pipe 23 Permeate Collection Pipe 26 Lower Header Pipe 27 Start-up Pipe 28 Falling pipe 29 Undiluted solution passage SS Foreign matter

Claims (1)

[Claims] 1. A membrane separation device having a flat membrane module immersed in a stock solution in a container, wherein a treatment liquid is taken out from a permeate recovery pipe connected to the flat membrane module, in a unit membrane module adjacent to each other. A membrane separation device characterized in that the position of the tip portion is different.