JPH07194947A - Membrane module - Google Patents

Abstract

PURPOSE:To provide a membrane module with a small friction resistance and a uniform membrane face sweeping flow and by which an apparatus can be large-sized by providing supporting materials in a hollow membrane supporting plates and forming flow paths for a membrane transmitting liq. between the supporting materials. CONSTITUTION:A hollow membrane supporting plate 21 is prepd. by connecting peripheral parts of a pair of flat plates 19 provided with fine holes 18 or fine slits each other. A membrane module is prepd. by arranging an org. filter membrane 22 covering the surface of this membrane supporting plate 21 and providing a suction nozzle 23 for taking out a membrane transmitting liq. on this membrane supporting plate 21 by making the hollow inside to be negative pressure. A plurality of lines of plat plate-like vertical supporting materials 24 supporting vertically the flat plates 19 are provided in the taking-out direction of the membrane transmitting liq. in the membrane supporting plate 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane module of a membrane filtration device used for solid-liquid separation in the treatment of activated sludge of organic wastewater.

[0002]

2. Description of the Related Art Conventionally, in the treatment of activated sludge of organic wastewater, Japanese Examined Patent Publication No. 4-70958 and Japanese Patent Laid-Open No. 4-26512.
No. 8, Japanese Patent Application No. 1-37241, Japanese Patent Laid-Open No. 4-33479.
Various membrane filtration devices such as that proposed in No. 1 are used. In this type of membrane filtration device, generally, a plurality of membrane modules are arranged in parallel at regular intervals by immersing them in water to be treated in a treatment tank, and an air diffuser is provided below the membrane module. The membrane module has a membrane permeate flow channel formed on the membrane permeation side, and by applying suction negative pressure to this channel,
Suspended substances such as microbial particles and inorganic particles in the water to be treated are captured by the filtration membrane, and the clean membrane permeate that permeates the filtration membrane and flows into the membrane permeate flow path is taken out of the treatment tank. It is configured. Then, the ascending flow parallel to the membrane surface generated by the air lift action of the gas bubbles supplied from the air diffuser separates the membrane surface deposit from the filtration membrane.

In the above Japanese Patent Publication No. 4-70958, a membrane module is provided in which a flat plate type membrane having a felt-like spacer for a permeate channel interposed between two flat membranes is connected to a pair of permeate water collecting pipes. Is disclosed.

Further, Japanese Patent Laid-Open No. 4-265128 discloses a membrane module in which a plate-shaped spacer made of a porous material having a filtration function is provided with a planar separation membrane. In addition, Japanese Patent Application No. 1-37241, Japanese Patent Application No. 4-334791.
In the No., the front and back of the filter plate consisting of a solid plate is covered with a filtration membrane, and a felt or net is interposed between the filter plate and the filtration membrane,
A membrane module has been proposed in which a membrane permeate flow channel is secured by forming a wrinkle on the surface of a filter plate. Further, a membrane module has been proposed in which a large permeate or a grain is formed on the surface of a filter plate to reach a water collecting portion to secure a membrane permeate flow path.

[0005]

However, in the case of the membrane module described in Japanese Patent Publication No. 4-70958, the rigidity is insufficient and the flow width of the water to be treated between the membrane modules is irregular due to the water flow. Therefore, the sweeping effect of the film surface deposits cannot be obtained uniformly over the entire film surface,
There is a problem that not only a high filtration rate cannot be obtained, but also film surface deposits are locally accumulated.

Further, in the case of the membrane modules described in JP-A-4-265128, JP-A-1-372241 and JP-A-4-334791, although the above-mentioned problem of rigidity is solved, a porous body and felt are used. Since the cross section of the permeated liquid channel formed by the texture is small, the frictional resistance when the permeated liquid flows through the channel is large, and it is difficult to increase the size of the membrane module.

Further, in a membrane module in which a large groove is formed on the surface of a filter plate to secure a membrane permeate flow channel, the filter plate is easily bent, and like the membrane module of Japanese Patent Publication No. 4-70958, There is a problem that the sweeping effect of the film surface deposits cannot be obtained uniformly with respect to the film surface. Therefore, even in this case,
It is difficult to increase the size of the membrane module.

The present invention solves the above-mentioned problems, and the frictional resistance when the membrane permeate flows through the permeate flow path is small,
It is an object of the present invention to provide a membrane module in which a membrane sweep can be uniformly obtained over all membrane surfaces and the apparatus can be made larger.

[0009]

In order to solve the above problems, in the membrane module of the present invention, a pair of flat plates provided with fine holes or fine slits are connected to each other at their peripheral portions to form a hollow membrane support plate. Then, the organic filtration membrane is arranged so as to cover the surface of the membrane supporting plate, and the membrane supporting plate is provided with a means for taking out the membrane permeated liquid by making the hollow inside a negative pressure, and at the inside of the membrane supporting plate, A plurality of rows of flat plate-shaped vertical support members for vertically supporting the flat plate are provided in the direction of taking out the membrane permeate.

In the membrane module of the present invention, a flat plate-shaped diagonal support member for obliquely supporting the flat plate is provided between the vertical support members. Further, the membrane module of the present invention is one in which a spacer that forms a predetermined gap is interposed between the membrane supporting plate and the organic filtration membrane.

Further, the membrane module of the present invention is one in which minute grooves are formed on the surface of a flat plate.

[0012]

With the above structure, the membrane permeated liquid that has permeated the filtration membrane enters the inside of the hollow membrane support plate through the fine holes or micro slits formed in the flat plate of the membrane support plate, and supports the flat plate. It is taken out of the membrane module through the flow path of the membrane permeation liquid formed between the materials. At this time, since the membrane supporting plate is hollow, the cross section of the flow path is large,
The frictional resistance of the membrane-permeated liquid when flowing through the channel is small. Further, since the hollow membrane supporting plate is supported from the inside by the vertical supporting member, the bending of the membrane supporting plate is prevented. From these, high filtration efficiency is obtained, and the width of the treated water flow path between the rigid membrane modules does not change irregularly under the influence of the water flow, and the membrane surface deposits on all membrane surfaces. Since the scavenging effect can be obtained evenly, it is possible to increase the size of the membrane module.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a cross-sectional view and a schematic plan view, respectively, for explaining the overall configuration of a membrane filtration device of an embodiment in which the membrane module of the present invention is arranged. The aeration tank 1 purifies the raw water 5 supplied from the raw water supply pipe 4, and inside the aeration tank 1, a submerged membrane filtration device 2 and an air diffusing pipe 3 are provided. The membrane filtration device 2 is for performing solid-liquid separation of the aeration tank mixed liquid 8 generated by the activated sludge treatment of the raw water 5 and the like, and a plurality of membrane modules are provided inside a rectangular box frame 9 whose upper and lower surfaces are open. 10 are vertically arranged in parallel at regular intervals, and the membrane module 10 is immersed with the top submerged. The air diffuser 3 is for blowing an aeration gas 11 containing oxygen such as air between the membrane modules 10, is arranged immediately below the membrane filtration device 2, and has an air supply pipe 12
It is connected to the blower 13 via. In addition, the membrane module 10 is provided with the membrane permeate tank 1 via the membrane permeate suction pipe 14.
5, a suction pump 17 for sucking the membrane permeated liquid 16 is provided in the middle of the membrane permeated liquid suction pipe 14.

3 to 5 show a membrane module according to a first embodiment of the present invention, FIG. 3 is a front view of the membrane module, FIG. 4 is a longitudinal sectional view thereof, and FIG. 5 is a transverse sectional view thereof. The membrane module is composed of a pair of flat plates 1 provided with micro holes 18 having a diameter of about 1 to 3 mm.
9 and 19 are connected to each other by a flat plate-shaped connecting support member 20 to form a hollow membrane supporting plate 21 whose entire circumference is closed, and the organic filter membrane 22 is covered by covering both sides of the membrane supporting plate 21. , 2
2, the membrane support plate 21 is provided with a suction nozzle 23 that communicates with the hollow interior to take out the membrane permeate.

The membrane supporting plate 21 is provided therein with a plurality of flat plate-like vertical supporting members 24 in a direction in which the membrane permeate is taken out by the suction nozzle 23.
9 and 19 are supported vertically, and support members 20 and 2
A channel A for the membrane permeate is formed between 4 and 24. The support member 24 is provided on the suction nozzle 23 side at a distance from the inner peripheral surface of the connection support member 20, and the suction nozzle 23 is provided.
The water collecting portion B is formed on the side. The micropores 18 are provided along the membrane permeate flow path A between the support materials, and each vertical support material 24 is provided with micropores 25 through which the membrane permeate liquid passes to the adjacent membrane permeation flow path A. Good.

Further, the filtration membrane 22 which is a microfiltration membrane or an ultrafiltration membrane arranged so as to cover the surface of the membrane supporting plate 21 is
The periphery of the filtration membrane 22 is fixed to the membrane support plate 21 by adhesion or fusion. Then, between the membrane supporting plate 21 and the filtration membrane 22, a spacer 26 made of a material such as felt, non-woven fabric or rusher having three-dimensionally fine communication holes is provided, and between the membrane supporting plate 21 and the filtration membrane 22. Holds a predetermined gap.

The operation of the above structure will be described below.
The raw water 5 sent from the raw water supply pipe 4 into the aeration tank 1 is aerated by the aeration gas 11 blown from the blower 13 to the membrane module 10 through the air supply pipe 12 and the diffuser pipe 3 to be treated with activated sludge. It becomes the mixed liquid 8. The mixed liquid 8 is solid-liquid separated by the filtration membrane 22 by the suction negative pressure applied to the inside of the membrane support plate 21 through the membrane permeation fluid suction pipe 14 from the suction pump 17, and passes through the filtration membrane 22 to obtain a clean membrane permeation. The liquid 16 enters the inside of the membrane supporting plate 21 through the minute holes 18, passes through the suction nozzle 23 and the membrane permeation liquid suction pipe 14, and is sent to the membrane permeation liquid tank 15. Further, the aeration gas 11 rising between the membrane modules 10 causes an upward flow parallel to the membrane surface between the membrane modules 10 due to the air lift action of the bubbles, and this rising flow causes the membrane surface of the filtration membrane 22 to adhere. The kimono is removed.

At this time, the membrane permeate 16 enters the inside of the hollow membrane support plate 21, and then the support materials 20, 2
Since it is collected in the water collecting part B through the membrane permeated liquid flow passage A between Nos. 4 and 24 and taken out to the outside of the membrane module 10, the cross section of the flow passage is large and the frictional resistance when flowing in the flow passage is small. The micropores 25 ensure a flow path between the membrane permeate liquid flow paths A.

Since the hollow membrane supporting plate 21 is supported from inside by the vertical supporting member 24, the membrane supporting plate 21 shown in FIG.
The bending of the treated water flow path between the membrane modules 10 and 10 which has rigidity can be prevented from curving in the X-axis and Y-axis directions in the above, and therefore the membrane surface deposition on the entire membrane surface can be prevented. The sweeping effect of the object can be obtained evenly.

Further, since the filtration membrane 22 is held by the membrane support plate 21 in a state where a predetermined gap is always maintained between the filtration membrane 22 and the membrane support plate 21, the membrane permeated liquid 16
Serves as a flow path for leading to the micropores 18.

FIG. 6 is a cross-sectional view of the membrane module of the second embodiment of the present invention. The membrane module of this embodiment is the first
The membrane module of the embodiment is different from the support members 20 and 2
In addition, a flat plate-shaped diagonal support member 27 for diagonally supporting the flat plates 19 and 19 is provided between the upper and lower ends of the adjacent support members by connecting between the upper ends of the adjacent support members and the lower ends of the other support members. is there. Each diagonal support member 27 is also provided with minute holes 27a so that the membrane permeate on both sides of the support member 27 can pass through.

With the configuration of this embodiment, the same operation as that of the first embodiment can be obtained, and the Y-axis direction curve of the membrane support plate described above with reference to FIG. 3 is prevented to prevent the membrane module. The rigidity of can be further increased.

FIG. 7 is a partial front view showing the membrane module of the third embodiment of the present invention. The membrane module of this embodiment differs from the membrane module of the first embodiment in that the flat plate 1
In FIG. 9, a minute slit 28 in the width direction of the permeated liquid channel A which replaces the minute hole is provided, and a minute groove 29 in the length direction of the permeated liquid channel A communicating with the minute slit 28 is provided on the entire surface of the flat plate 19. It is a point. Moreover, in this membrane module, no spacer is provided.

With the configuration of this embodiment, the same operation as that of the first embodiment can be obtained, and the membrane permeate on the surface of the flat plate 19 can be easily guided to the minute slits 28 by the minute grooves 29, and the minute slits 28 can be formed. Is larger than the micropores, the membrane-permeated liquid that has permeated the filtration membrane 22 is more likely to flow into the membrane supporting plate 21.

FIG. 8, FIG. 9 and FIG. 10 are respectively a front view, a horizontal sectional view and a vertical sectional view of a large-sized membrane module according to the fourth embodiment of the present invention. The membrane module of this embodiment differs from the membrane module of the first embodiment in that a pair of flat plates are connected to each other at two opposite sides and a water collecting portion is provided at the other two sides.

That is, a pair of rectangular flat plates 31, 31 having the minute holes 30 are connected by a connecting support member 32 at the long side peripheral portion 31a to form a hollow membrane support plate 33,
Inside the membrane supporting plate 33, a plurality of rows of flat plate-shaped vertical supporting members 34 in a direction parallel to the connecting supporting member 32 are provided.
4, the flat plates 31, 31 are vertically supported, and a membrane permeate liquid flow path C is formed between the support members 32, 34, 34. Further, between the support members 32, 34, 34, a flat plate shape having micro holes 35a for connecting the upper ends of the adjacent one support member and the lower end of the other support member to obliquely support the flat plates 31, 31 is provided. The diagonal supporting member 35 is provided.

The short side peripheral edge 31b of the flat plate 31
A water collecting cap 36 having a U-shaped cross section is externally inserted to form a water collecting portion D between the end surfaces of the flat plates 31 and 31 and the inner side surface of the water collecting cap 36, and one end surface of the water collecting cap 36 is formed. Is closed by another U-shaped cap 37, for example, and another end surface of the water collecting cap 36 is closed by a cap 39 having a suction nozzle 38. Further, a spacer 40 is provided on the surface of the flat plate 31, and the filtration membrane 41 is covered with the spacer 40.
Is fixed to the water collecting cap 36.

With the structure of this embodiment, the same operation as that of the first embodiment can be obtained, and the diagonal supporting member 35 is used.
By obliquely supporting the flat plates 31, 31 from the inside, it is possible to prevent the membrane supporting plate 33 from bending in the Y-axis direction and to secure the rigidity of the large-sized membrane module, and to collect water at the water collecting portions D at both ends of the membrane supporting plate 33. By providing a suction negative pressure from both ends of the membrane permeate flow channel C, the membrane permeate can be easily taken out even in a large membrane module.

[0029]

As described above, according to the present invention, a supporting member is provided inside a hollow membrane supporting plate, and the supporting member gives rigidity to the membrane module, and the membrane is provided between the supporting members. It was configured to form a flow path for the permeated liquid. For this reason,
The membrane permeate that has permeated the filtration membrane enters the inside of the membrane support plate, and then is taken out of the membrane module through the permeate flow passage with a large cross section between the support members. small. Further, the width of the treated water flow path between the rigid membrane modules does not change irregularly due to the influence of the water flow, and the effect of sweeping the membrane surface deposits can be uniformly obtained over the entire membrane surface. From these, a high filtration rate can be obtained, and the size of the membrane module can be increased.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating the overall configuration of a membrane filtration device of an embodiment in which a membrane module of the present invention is arranged.

FIG. 2 is a schematic plan view of the membrane filtration device of FIG.

FIG. 3 is a front view of the membrane module according to the first embodiment of the present invention.

4 is a vertical cross-sectional view of the membrane module of FIG.

5 is a cross-sectional view of the membrane module of FIG.

FIG. 6 is a cross-sectional view of the membrane module according to the second embodiment of the present invention.

FIG. 7 is a partial front view of the membrane module according to the third embodiment of the present invention.

FIG. 8 is a front view of a membrane module according to a fourth embodiment of the present invention.

9 is a cross-sectional view of the membrane module of FIG.

10 is a vertical cross-sectional view of the membrane module of FIG.

[Explanation of symbols]

 18 Micropores 19 Flat plate 21 Membrane support plate 22 Organic filtration membrane 23 Suction nozzle 24 Vertical support material 26 Spacer 27 Diagonal support material 28 Micro slit 29 Microgroove 30 Micropore 31 Flat plate 33 Membrane support plate 34 Vertical support material 35 Diagonal support material 38 Suction nozzle 40 Spacer 41 Organic filtration membrane

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Soeda 1-247 Shikitsuhigashi, Naniwa-ku, Osaka-shi, Osaka Kubota Corporation

Claims (4)

[Claims] 1. A hollow membrane supporting plate is formed by connecting a pair of flat plates provided with micropores or microslits to each other at their peripheral portions, and an organic filtration membrane is disposed so as to cover the surface of the membrane supporting plate.
The membrane supporting plate is provided with a means for taking out the membrane permeated liquid by using a negative pressure inside the hollow, and a flat plate-shaped vertical support member for vertically supporting the flat plate is taken out of the membrane supporting plate. A membrane module having a plurality of columns arranged in a direction. 2. The membrane module according to claim 1, wherein a flat plate-shaped diagonal support member for obliquely supporting the flat plate is provided between the vertical support members. 3. The membrane module according to claim 1, wherein a spacer that forms a predetermined gap is interposed between the membrane supporting plate and the organic filtration membrane. 4. The membrane module according to claim 1, wherein fine grooves are formed on the surface of the flat plate.