JPH11188244A - Immersion type film treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an immersion type film treating device provided with a spiral type film element less in secular deterioration of a transmission water quantity and enabling to obtain a high transmission water quantity, and being high in packing density of the film. SOLUTION: The spiral type film element 40 in which a separation film is wound spirally to form it, raw water flowing from one end surface of the wound body into a raw water flow path between separation films themselves and flowing out from the other end surface as concentrated water and also transmitted water flows out from a socket 25 at the other end surface, is piped in a raw water tank under immersion, and the inside of a transmission water flow path is sucked with a suction pump 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus used for membrane separation of water, and more particularly to an immersion type membrane treatment apparatus in which a membrane element is immersed in a raw water tank.

[0002]

2. Description of the Related Art In an immersion type membrane treatment apparatus in which a membrane element is immersed in a raw water tank, raw water permeates the membrane by suctioning the permeated water side of the membrane element, and permeated water is taken out. Conventionally, as a membrane element of such a submerged membrane treatment apparatus, an element in which a plurality of flat membranes are arranged in parallel or a number of hollow fiber membranes are arranged in a line is often used.

In order to flow raw water between the flat membrane element and the hollow fiber membrane element, a stirrer is provided in the raw water tank, or an air diffuser is provided below the membrane element to generate an upward flow. Has been done.

[0004]

An immersion type membrane processing apparatus having a flat membrane as a membrane element has the disadvantage that the packing density of the membrane is low and the entire apparatus becomes large. Further, in the case of the hollow fiber membrane element, there is a disadvantage that SS (suspension substance) is easily deposited and deposited.

An object of the present invention is to provide an immersion-type film processing apparatus which overcomes the above disadvantages, has a high film filling density, can be downsized, and hardly deposits SS.

[0006]

The immersion type membrane treatment apparatus according to the present invention is an immersion type membrane treatment apparatus in which a membrane element is immersed in a raw water tank, wherein the membrane element is formed by winding a separation membrane in a spiral shape. The spiral membrane element is characterized in that the raw water flows into the raw water flow path between the separation membranes from one end face of the wound body and flows out as concentrated water from the other end face.

In such an immersion type membrane processing apparatus, a spiral type membrane element is adopted, and the packing density of the membrane is high. Further, since the SS adhesion layer (gel layer) is renewed by the flow of the raw water, the amount of permeated water is large.

In the present invention, the membrane element is such that a permeated water flow path material is disposed inside the bag-shaped membrane, and a raw water flow path material is disposed between the bag-shaped membranes. Is the first,
It is a substantially rectangular shape having second, third and fourth sides, the first, second and third sides are sealed, the fourth side is partially open, and the remainder is It is a closed part, and the fourth
A first side perpendicular to the side of the roll is applied to the shaft to wind the bag-like membrane to form a roll, and the fourth side faces the rear end face of the roll, and the fourth With the second side facing the side facing the front end face of the wound body, the raw water flow path between the bag-like membranes is entirely sealed with the third side, and the fourth side is closed. It is preferable that, in the side portion, a portion overlapping the open portion of the bag-like film is a closed portion, and a portion overlapping the closed portion of the bag-like film is an open portion.

In such a spiral membrane element, raw water flows into the raw water flow path from the front end face of the wound body. The raw water flows through the raw water flow path in a direction substantially parallel to the axis of the wound body, and then flows out as concentrated water from the raw water flow path opening at the rear end face of the wound body.

The water that has passed through the bag-like membrane flows in the bag-like membrane in a direction substantially parallel to the axis of the wound body, and flows out of the bag-shaped membrane opening at the rear end face of the wound body.

As described above, since the permeated water flows in the bag-shaped membrane in a direction parallel to the axis of the wound body, the water collecting pipe used in the conventional spiral type membrane element becomes unnecessary. Then, there is no flow resistance when flowing into the water collecting pipe from inside the bag-shaped membrane, and the flow resistance of permeated water is reduced.

Since the water collecting pipe is eliminated, the length of the bag-shaped membrane in the winding direction can be increased accordingly.
The membrane area can be expanded. And even if the length in the winding direction of the bag-like membrane is increased, the flow resistance of the permeated water does not increase,
The amount of permeated water can be increased.

In this spiral type membrane element, the raw water flow path is opened only at a part of the rear end face of the wound body. Can be increased, and the adhesion of dirt in the downstream area of the raw water flow path can be prevented.

In the present invention, the open portion of the bag-shaped membrane is disposed on the inner peripheral side of the rear end face of the roll, and the raw water flow path is disposed on the outer peripheral side of the rear end face of the roll. It is preferable that an annular member for separating the permeated water flowing out from the open part of the wound body and the concentrated water flowing out from the open part of the raw water flow path be connected to the rear end face of the wound body. By connecting a permeate extraction pipe to this annular member, permeate can be extracted without receiving inflow of raw water.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a perspective view of one bag-like membrane used for the spiral membrane element according to the embodiment of the present invention and a shaft around which the bag-like membrane is wound. FIGS. 1B and 1C are cross-sectional views taken along lines BB and CC of FIG. 1A, respectively. FIG. 2 is a sectional view showing a method of winding a bag-like membrane around a shaft, and FIG.
FIG. 4 is a perspective view showing an engagement relationship between a wound body and a socket, and FIG. 4 is a sectional view of an immersion type membrane processing apparatus in which a spiral type membrane element is immersed.

The bag-like membrane 1 used in this embodiment
0 is a square or rectangular shape, and the first side 1
1, second side 12, third side 13, and fourth side 1
Four. This bag-like membrane 10 is formed by stacking two separation membrane films and forming a first side 11, a second side 12,
The third side portion 13 and a part of the fourth side portion 14 are bonded. Instead of laminating the two films, one long separation membrane film is folded back at the second side portion, and the separation film folded at the first side portion 11 and the third side portion 13 is folded. The membrane films may be adhered to each other with an adhesive or the like, and a part of the fourth side portion 14 may be formed into a bag-like shape that is an open portion without being adhered.

In this embodiment, the fourth side 1
The separation membrane films of the bag-like membrane 10 are not bonded to each other from the middle of 4 to the first side portion 11, forming an open portion 30 for outflow of permeated water. Further, from the middle of the fourth side portion 14 to the third side portion 13, the separation membrane films of the bag-like membrane 10 are adhered to each other, forming a closing portion 31 for preventing outflow of permeated water. I have.

A flow path material (for example, made of a mesh spacer) 15 is inserted and arranged in the bag-like membrane 10.

On one surface of the bag-like film 10, an adhesive 1
6 is adhered and adhesives 17 and 18 are adhered to the other surface, and the bag-like film 10 is wound around the shaft 20. The adhesive 16 is applied along the first side 16, and the adhesive 17 is applied along the third side 13. The adhesive 18 is applied along the opening 30 for outflow of permeated water from the middle part in the longitudinal direction of the fourth side part 14 to the first side part 11.

By winding a plurality of bag-shaped membranes 10 around the shaft 20, the overlapped bag-shaped membranes 10 are joined in a water-tight manner at the adhesives 16, 17 and 18. Thus, a raw water flow path through which raw water (and concentrated water) flows is formed between the bag-like membranes 10, 10,....
As the adhesive 18 cures, an open portion for the outflow of raw water (concentrated water) is formed on the outer peripheral side on the rear end surface of the wound body, and a closed portion for preventing the outflow of raw water is formed on the inner peripheral side. You.

In this embodiment, the fourth side 1
The fin 19 extends from the boundary between the open portion 30 for permeated water outflow and the closed portion 31 for permeated water outflow out of 4, toward the rear of the wound body. The fins 19 are made of, for example, a synthetic resin film or sheet, and are preferably bonded to the bag-like film 10 by adhesion or the like.

By winding a plurality of bag-shaped membranes 10 around the shaft 20 via a mesh spacer 29 as shown in FIG. 2, a wound body 24 is formed as shown in FIG. The fin 19 extends from the rear end face of the wound body 24. By providing the fins 19 at the same location on the fourth side portion 14 of each bag-like membrane 10, the fins 19 are located on the same radius from the axis of the wound body 24, and the fins 19 overlap. The fin 19 forms a ring-shaped protrusion. The rear end of the cylindrical socket 25 is inserted into the ring-shaped protrusion, and the socket 25 and the fin 19 are joined with an adhesive or the like. The socket 25
May be externally fitted to the fins 19. Further, a cutting groove may be formed on the rear end face of the wound body 24 along the fins 19 with a lathe, and the end of the socket 25 may be embedded in the groove.

By joining the socket 25 and the fin 19 in this manner, a permeated water outflow area on the inner peripheral side of the rear end face of the wound body 24 and a concentrated water outflow area on the outer peripheral side of the socket 25 are defined. .

The outer periphery of the wound body 24 is restrained by a restraining member (for example, a winding sheet or a tubular member) so that the wound body 24 is not unwound, thereby forming a spiral membrane element.

As shown in FIG. 4, the spiral membrane element 40 is immersed in a raw water tank such that the axial direction of the membrane element 40 (the longitudinal direction of the shaft 20) is vertical. A suction pump 42 is connected to the socket 25 via a pipe 41 for extracting permeated water. On the upper side of the membrane element 40, a stirrer 50 for sending a water flow downward is installed. By operating the agitator 50 and the suction pump 42, the raw water flows into the raw water flow path of the membrane element 40, and the permeated water is taken out.

In this spiral type membrane element 40, as shown in FIG. 4, raw water flows into the raw water flow path between the bag-like membranes 10 from the front end surface (upper end surface) of the wound body 24. This raw water flows through the raw water flow path in a direction substantially parallel to the axis of the membrane element 40, and the socket 25 at the rear end of the wound body 24
Flows out from the outer end face as concentrated water. Then, while the raw water flows through the raw water flow path, the water permeates into the bag-like membrane 10, and the permeated water flows out from the inner peripheral side of the socket 25 on the rear end face of the wound body 24, And suction pump 42
Is taken out through.

In the immersion type membrane processing apparatus having such a spiral type membrane element 40, the packing density of the membrane is extremely high, and the entire apparatus becomes compact. Further, the strength of the membrane element itself is higher than that of a conventional flat membrane element or hollow fiber element.

The spiral membrane element 40
In this case, since the permeated water flows in the bag-shaped membrane 10 in a direction parallel to the axis of the wound body 42 and is taken out from the rear end face, the water collecting pipe used in the conventional spiral membrane module is unnecessary. It is. For this reason, the flow resistance when flowing from the bag-like membrane into the water collecting pipe is eliminated, and the permeated water flow resistance is significantly reduced.

Further, the water collecting pipe is omitted, and the length of the bag-like membrane 10 in the winding direction can be increased by that much.
It is possible to increase the film area. Even if the length of the bag-like membrane in the winding direction is increased, the permeated water flow resistance does not increase,
The amount of permeated water can be increased.

In the membrane element 40, since the raw water always flows along the membrane surface, the amount of permeated water can be maintained.
Also, the attached gel layer on the membrane surface is renewed by the raw water flow,
No excessive gel layer is formed and the amount of permeated water is large.

In this embodiment, the outlet portion of the raw water flow passage is provided only outside the socket 25, and the outlet (the most downstream portion) of the raw water flow passage is narrowed. Also on the downstream side, the flow rate of the raw water (concentrated water) becomes sufficiently large, and it is possible to prevent the adhesion of dirt in the downstream area of the raw water flow path.

In the membrane element 40, since the raw water flows evenly between the wound membranes, almost the entire membrane surface is contaminated, and there is no local membrane contamination.

When the membrane element 40 is backwashed, a backwash fluid (for example, water, a gas such as air, or a gas mixture) is flown through the pipe 41 into the bag-like membrane 10. This backwashing fluid is sent directly from the socket 25 into the bag-like membrane 10 and is uniformly supplied to almost the entire inside of each bag-like membrane 10.
Then, the back flow is almost uniformly returned from the entire surface of the bag-shaped membrane 10 to the raw water flow path side, and the entire membrane surface of the bag-shaped membrane 10 can be back-washed uniformly and evenly.

In the embodiment shown in FIG. 4, the raw water flow is formed by the stirrer 50. However, as shown in FIG. 5, an air diffuser 55 is provided below the membrane element 40, and the raw water flow is formed by rising bubbles. You may do it.

In the present invention, it is preferable that a cylindrical guide 60 is provided around the outer periphery of the membrane element 40 so that the rising raw water can surely flow into the raw water flow path of the membrane element 40. This guide 60 may be provided in FIG.

[0036]

As described above, the immersion type membrane processing apparatus of the present invention has a high packing density of the membrane, and the whole apparatus can be made small and compact. The spiral-wound membrane element employed in the present invention has a small decrease in the amount of permeated water over time and can stably obtain a high permeated water amount. Also, it is possible to increase the flow rate of the raw water (concentrated water) in the downstream area of the raw water flow path, thereby preventing the adhesion of dirt in the downstream area of the raw water flow path. Furthermore, the spiral-type membrane element employed in the present invention can perform backwashing uniformly, which can also increase the amount of permeated water in the immersion-type membrane treatment apparatus.

[Brief description of the drawings]

FIG. 1A is a perspective view of a bag-like membrane according to an embodiment,
(B) is a sectional view taken along line BB of (a), and (c) is a sectional view taken along line CC of (a).

FIG. 2 is a cross-sectional view illustrating a method of winding a bag-shaped membrane of the spiral membrane element according to the embodiment.

FIG. 3 is a perspective view showing an engagement relationship between a wound body and a socket.

FIG. 4 is a cross-sectional view of the immersion type film processing apparatus according to the embodiment.

FIG. 5 is a sectional view of an immersion type film processing apparatus according to another embodiment.

[Explanation of symbols]

 Reference Signs List 10 bag-like membrane 11 first side 12 second side 13 third side 14 fourth side 15 flow path material 16, 17, 18 adhesive 19 fin 20 shaft 24 wound body 25 socket 29 Mesh spacer 30 Open part for permeated water outflow 31 Closed part for permeated water outflow prevention 40 Spiral type membrane element 41 Piping 42 Suction pump 50 Stirrer 55 Air diffuser 60 Cylindrical guide

Claims (4)

[Claims] 1. An immersion type membrane treatment apparatus comprising a membrane element immersed in a raw water tank, wherein the membrane element is formed by winding a separation membrane in a spiral shape, and raw water flows from one end face of the wound body to the separation membranes. A spiral-type membrane element that flows into a raw water flow path between the above and the concentrated water and the permeated water flow out from the other end face. 2. The membrane element according to claim 1, wherein the permeated water flow path material is disposed on an inner surface of the bag-shaped membrane, and a raw water flow path material is disposed between the bag-shaped membranes. The bag-like membrane is substantially rectangular with first, second, third and fourth sides, the first, second and third sides are sealed,
A part of the fourth side is an open part and the remaining part is a closed part, and a first side perpendicular to the fourth side is applied to a shaft to wind a bag-like membrane. A body having a fourth side facing the rear end face of the wound body, a second side facing the fourth side facing the front end face of the wound body, In the raw water flow path between the membranes, the entire third side portion is sealed, and in the fourth side portion, a portion overlapping with the open portion of the bag-shaped membrane is a closed portion, An immersion type membrane processing apparatus characterized in that a portion overlapping the closed portion of the bag-like film is an open portion. 3. The roll-shaped membrane according to claim 2, wherein the open portion of the bag-shaped membrane is arranged on an inner peripheral side of a rear end face of the wound body, and the raw water flow path is arranged on an outer peripheral side of a rear end face of the wound body. An annular member for separating the permeated water flowing out of the open portion of the bag-shaped membrane from the concentrated water flowing out of the open portion of the raw water flow path is connected to a rear end surface of the wound body. An immersion type membrane processing apparatus characterized by the above-mentioned. 4. The immersion type membrane processing apparatus according to claim 1, further comprising means for flowing raw water through a raw water flow path of the spiral type membrane element.