JP2012161791A - Membrane separation equipment, membrane separation device and method for operating membrane separation equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane separation equipment which can suppress an operation cost.SOLUTION: The membrane separation equipment has a treatment tank 3 for storing water to be treated 2 and a membrane separation device 6 which is arranged by being immersed in the water to be treated 2 in the treatment tank 3 to obtain treated water 5 which has passed through a filter membrane. The membrane separation device 6 has a plurality of membrane units 7, 8 which are arranged adjacent to each other in a horizontal direction and a wall body 9 which partitions between the membrane units 7, 8 and the treatment tank 3 while surrounding these membrane units 7, 8 and further a communication part 28 which feeds the water to be treated 2 in the wall body 9 and discharges the water to be treated 2 from the wall body 9 is provided above the membrane units 7, 8 of the wall body 9. Further the membrane units 7, 8 are respectively provided, at its lower parts, with air diffusers 12, 13 which can regulate air diffusion amount.

Description

  The present invention relates to a membrane separation facility, a membrane separation apparatus, and a method for operating the membrane separation facility for solid-liquid separation of a liquid to be treated such as sewage wastewater or purified water.

  Conventionally, as this type of membrane separation equipment, for example, as shown in FIG. 17, a reaction tank 81 and a solid-liquid separation tank 82 are provided adjacent to each other, and the solid-liquid separation tank 82 is a sludge mixed liquid. A membrane separation device 85 is provided that obtains a treatment liquid that is immersed in the liquid to be treated 83 and permeates the filtration membrane. The membrane separation device 85 has a plurality of membrane units 86 arranged adjacent to each other in the horizontal direction. Each membrane unit 86 has a plurality of filtration membranes and is provided with an air diffuser 87 at the bottom.

  An auxiliary air diffuser 88 is provided at the bottom of the reaction tank 81. The reaction tank 81 and the solid-liquid separation tank 82 are partitioned by a partition wall 89. A supply pipe 90 for supplying the liquid 83 to be processed from the reaction tank 81 to the solid-liquid separation tank 82 is provided, and a supply pump 91 is provided in the supply pipe 90. The partition wall 89 is formed with a return opening 92 for returning the liquid 83 to be processed in the solid-liquid separation tank 82 to the reaction tank 81.

  According to this, when the supply pump 91 is operated, the liquid 83 to be processed in the reaction tank 81 is supplied into the solid-liquid separation tank 82 through the supply pipe 90, and accordingly, in the solid-liquid separation tank 82. The liquid 83 to be treated is returned into the reaction tank 81 through the return opening 92. Thereby, the to-be-processed liquid 83 circulates between the reaction tank 81 and the solid-liquid separation tank 82.

  A large amount of air is diffused from the air diffuser 87 of a part of the plurality of membrane units 86 and a small amount of air is diffused from the air diffuser 87 of the remaining film unit 86. An upward flow 93 of the liquid 83 to be processed is generated in the membrane unit 86 and a downward flow 94 of the liquid 83 to be processed is generated in the remaining membrane unit 86. The membrane surface of the filtration membrane of some membrane units 86 is washed by the upward flow 93.

  Further, since the bubbles released from the air diffuser 87 of the remaining membrane unit 86 into the downflow 94 rise against the downflow 94, the apparent rising speed is reduced, and the air bubbles spread over a wide area while drifting in the lateral direction. Move and surface. Thereby, the membrane surface of the filtration membrane of the remaining membrane unit 86 is washed over a wide area by the bubbles and the local flow (turbulent flow) associated with the movement of the bubbles, and the adhering matter adhering to the ends of the filtration membrane is peeled off. It can be prevented that it remains without.

  The membrane separation equipment as described above is described in Patent Document 1 below.

JP2008-246357

  However, in the above conventional model, the reaction tank 81 and the solid-liquid separation tank 82 are provided separately, and the membrane separation device 85 is provided in the solid-liquid separation tank 82. In order to circulate the to-be-processed liquid 83 between, the supply piping 90 and the supply pump 91 are needed, and there exists a problem that operation cost, such as the electric power cost for operating the supply pump 91, rises.

  It is an object of the present invention to provide a membrane separation facility, a membrane separation apparatus, and a method for operating the membrane separation facility that can reduce operating costs.

In order to achieve the above object, a membrane separation facility according to the first aspect of the present invention includes a treatment tank for storing a treatment liquid, and a treatment liquid that is disposed so as to be immersed in the treatment liquid in the treatment tank and that passes through the filtration membrane. A membrane separation device to obtain,
The membrane separation apparatus has a plurality of membrane units arranged adjacent to each other in the horizontal direction, and a wall body that partitions between the plurality of membrane units and the treatment tank,
Above the membrane unit of the wall body, a communication part for taking in and out the liquid to be treated into and out of the wall body is provided,
The lower regions of adjacent membrane units communicate with each other via the liquid to be processed.
Each membrane unit is provided with a diffuser at the bottom.

  According to this, air is diffused from the air diffuser of some of the plurality of membrane units, and an upward flow of the liquid to be processed is generated in some of the membrane units. Since this upward flow is formed by the liquid to be processed drawn in from the remaining film unit adjacent through the lower region, a downward flow of the liquid to be processed is generated in the remaining film unit. In a state where such a downward flow is maintained, a small amount of air is diffused from the air diffuser of the remaining membrane units than the air diffuser of the air diffusers of some membrane units.

  Thereby, the membrane surface of the filtration membrane of some membrane units is washed by the upward flow. In addition, the bubbles released from the air diffuser of the remaining membrane unit during the descending flow rise against the descending flow, so the apparent rising speed is reduced, and the air moves over a wide area while drifting in the horizontal direction. To do. As a result, the membrane surface of the filtration membrane of the remaining membrane unit is washed by the downward flow and extensively by the local flow (turbulent flow) accompanying the movement of the bubbles and bubbles. Therefore, it is possible to prevent the deposits attached to the corners of the filtration membrane from remaining without being peeled off.

  Moreover, a part of the rising flow that has risen flows out from the inside of the wall body to the outside of the wall body through the communicating portion. Further, the liquid to be treated outside the wall is drawn down in the vicinity of the liquid surface, and flows from the outside of the wall through the communicating portion to the inside of the wall. Thereby, the to-be-processed liquid in a processing tank circulates the inner side and the outer side of a wall body through a communicating part.

  At this time, since the membrane separation apparatus having a wall is immersed in the liquid to be treated in the treatment tank, the communication portion can be configured to face the upper side of each membrane unit. For this reason, the to-be-processed liquid can be circulated in a wide range through the communication part, and the supply pump and the supply piping for circulating the to-be-processed liquid become unnecessary, and the operating cost can be suppressed.

In the membrane separation facility according to the second aspect of the present invention, the upper region of adjacent membrane units is partitioned by a partition member.
According to this, air is diffused from the air diffuser of one membrane unit adjacent to each other, and an upward flow of the liquid to be processed is generated in one membrane unit. Since this upward flow is formed by the liquid to be processed drawn in from the remaining film unit adjacent through the lower region, a downward flow of the liquid to be processed is generated in the remaining film unit. Such a downward flow flows through the other adjacent membrane unit, reverses when flowing in the lower region of the membrane unit, and is drawn into the lower portion of the one membrane unit. Thereby, a to-be-processed liquid circulates in the up-down direction over one membrane unit and the other membrane unit.

The membrane separation facility according to the third aspect of the present invention is provided with an auxiliary air diffuser inside the processing tank and outside the wall body.
According to this, when biologically treating the liquid to be treated, such as sewage wastewater, a sufficient amount of oxygen necessary for biological treatment is treated by aeration of the liquid to be treated in the treatment tank from the auxiliary air diffuser. It can be fed into the liquid.

The fourth aspect of the present invention is a membrane separation apparatus for obtaining a treatment liquid that is immersed in a treatment liquid in a treatment tank and that passes through a filtration membrane.
A plurality of membrane units arranged adjacent to each other in the horizontal direction, and a wall body that partitions between the plurality of membrane units and the treatment tank,
Above the membrane unit of the wall body is provided with a communication part for taking the treatment liquid in and out of the wall body in and out of the wall body,
The lower regions of adjacent membrane units communicate with each other via the liquid to be processed.
Each membrane unit is provided with a diffuser at the bottom.

The fifth aspect of the present invention is a method for operating a membrane separation facility according to any one of the first to third aspects of the present invention,
Aeration is performed from the diffuser of some of the plurality of membrane units to generate an upward flow of the liquid to be processed in some of the membrane units and a downward flow of the liquid to be processed in the remaining membrane units. Is generated,
A small amount of air is diffused from the air diffuser of the remaining membrane unit while maintaining the downward flow.

  According to this, the membrane surface of the filtration membrane of some membrane units is washed by the upward flow. In addition, the bubbles released from the air diffuser of the remaining membrane unit during the descending flow rise against the descending flow, so the apparent rising speed is reduced, and the air moves over a wide area while drifting in the horizontal direction. To do. As a result, the membrane surface of the filtration membrane of the remaining membrane unit is washed extensively by bubbles and local flow (turbulent flow) associated with the movement of the bubbles, and the deposits attached to the corners of the filtration membrane are peeled off. It can be prevented that it remains.

A sixth aspect of the present invention is a method for operating a membrane separation facility according to any one of the first to third aspects of the present invention,
Air is diffused from the air diffuser of some of the plurality of membrane units, and air is not diffused from the air diffuser of the remaining membrane units.

  According to this, an upward flow of the liquid to be processed is generated in some of the membrane units, and this upward flow is formed by the liquid to be processed that is drawn in from the remaining film unit adjacent through the lower region, A downflow of the liquid to be treated is generated in the membrane unit. The membrane surface of the filtration membrane of some membrane units is washed by the upward flow. Further, the membrane surface of the filtration membrane of the remaining membrane unit can be cleaned to some extent by the downward flow without performing the diffusion from the diffuser of the remaining membrane unit.

  As described above, according to the present invention, the liquid to be processed can be circulated in a wide range through the communication portion, and the supply pump and the supply pipe for circulating the liquid to be processed are not necessary, and the operation cost can be suppressed. .

It is sectional drawing of the membrane separation equipment in the 1st Embodiment of this invention. It is a top view of a membrane separation equipment. It is a figure of the membrane unit of a membrane separation equipment, (a) is a partially notched perspective view of a membrane unit, (b) is a X direction arrow view in (a). It is sectional drawing of the membrane separation installation in the 2nd Embodiment of this invention. It is sectional drawing of the membrane separation equipment in the 3rd Embodiment of this invention. It is sectional drawing of the membrane separation equipment in the 4th Embodiment of this invention. It is sectional drawing of the membrane separation equipment in the 5th Embodiment of this invention. It is sectional drawing of the membrane separation equipment in the 6th Embodiment of this invention. It is sectional drawing of the membrane separation equipment in the 7th Embodiment of this invention. It is sectional drawing of the membrane separation equipment in the 8th Embodiment of this invention. It is a top view of the membrane separation installation in the 9th Embodiment of this invention. It is a top view of the membrane separation installation in the 10th Embodiment of this invention. It is a top view of the membrane separation installation in the 11th Embodiment of this invention. It is a figure of the air supply apparatus of the membrane separation installation in the 13th Embodiment of this invention. It is sectional drawing of the membrane separation equipment in the 14th Embodiment of this invention. It is a top view of a membrane separation equipment. It is sectional drawing of the conventional membrane separation installation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
First, the first embodiment will be described.

  As shown in FIGS. 1 to 3, reference numeral 1 denotes a membrane separation facility for biologically treating a treated water 2 (an example of a treated liquid) containing organic substances such as domestic wastewater, sewage, or factory wastewater to perform solid-liquid separation. . The membrane separation facility 1 includes a treatment tank 3 for storing the treated water 2 supplied from the raw water supply system 35, and a treated water that has been immersed in the treated water 2 in the treatment tank 3 and has passed through the filtration membrane 4. 5 (an example of the treatment liquid).

  The membrane separation device 6 includes two (a plurality of) membrane units 7 and 8 disposed adjacent to each other in the horizontal direction, and surrounds the membrane units 7 and 8, the membrane units 7 and 8, and the treatment tank 3. It has the wall body 9 which partitions between.

  Each of the membrane units 7 and 8 has a plurality of flat plate membrane elements 10 and a membrane case 11 in which these membrane elements 10 are accommodated. Each membrane element 10 has a filtration membrane 4 attached to both surfaces of a resin filter plate 18 and communicates with a treated water derivation system 19 for deriving treated water 5. The membrane elements 10 are arranged with the membrane surface of the filtration membrane 4 along the vertical direction, and are arranged in parallel at a predetermined interval. Between the membrane surfaces of the filtration membrane 4 of the membrane elements 10 facing each other, a flow path 34 for the water to be treated 2 that is open both vertically is formed.

  The membrane case 11 has a membrane filling portion in the upper portion and a draft tube portion in the lower portion. The membrane units 7 and 8 are respectively provided with air diffusers 12 and 13 capable of adjusting the amount of air diffused (discharged air volume) at the bottom. The air diffusers 12 and 13 are each composed of an air diffuser having a plurality of air holes.

  The membrane separation facility 1 is provided with an air supply device 14 for supplying air to the air diffusers 12 and 13. The air supply device 14 includes a blower 15 and a plurality of air supply pipes 16 connected between the blower 15 and each of the air diffusion devices 12 and 13. Each air supply pipe 16 is provided with a valve 17 for adjusting the flow rate of air supplied to the air diffusers 12 and 13. An automatic flow control valve or the like is used as the valve 17. When the opening degree of the valve 17 is increased, the amount of air diffused increases. When the opening degree of the valve 17 is reduced, the amount of air diffused decreases. When 17 is fully closed, the amount of air diffused is 0, that is, air is not diffused.

  The wall body 9 has a rectangular box-like structure with an open upper surface, and includes a square frame-like side wall portion 20 and a bottom wall portion 21 that closes a lower end portion of the side wall portion 20, and a processing tank. 3 is installed in the central part.

  The upper regions 22 of the membrane units 7 and 8 adjacent to each other communicate with each other via the water to be treated 2 and the lower regions 23 communicate with each other via the water to be treated 2. Further, the membrane units 7 and 8 are partitioned by a partition plate 25 (an example of a partition member) in a region between the upper region 22 and the lower region 23. The partition plate 25 is provided between a pair of opposing wall surfaces of the side wall portion 20. The membrane elements 10 are arranged in a direction perpendicular to the partition plate 25.

  Above the membrane units 7, 8 of the wall body 9, a communication portion 28 is provided for taking the treated water 2 into and out of the wall body 9 at the water surface portion 27 in the treatment tank 3. That is, the wall body 9 is submerged in the water to be treated 2 in the treatment tank 3, and a communication portion 28 is formed between the upper end of the wall body 9 and the water surface portion 27. The communicating portion 28 is formed over the entire upper periphery of the wall body 9 and faces the upper side of all the membrane units 7 and 8.

Further, the side wall portion 20 of the wall body 9 has an upper draft portion 20 a protruding upward from the upper ends of the membrane units 7 and 8 at the upper end portion.
The membrane separation facility 1 is connected to a sludge extraction system 29 that extracts excess sludge from the bottom of the membrane units 7 and 8 inside the wall body 9 and the bottom outside the wall body 9 to the outside of the treatment tank 3. The sludge extraction system 29 includes a sludge extraction pipe 29a and extraction valves 29b and 29c. The extraction valves 29b and 29c are desirably provided at positions where the inner bottom portion of the wall body 9 and the outer bottom portion communicate with each other unconditionally so that the treated water 2 does not come and go.

  A plurality of auxiliary air diffusers 30 (another air diffusers) are provided at the bottom in the processing tank 3 and outside the wall body 9. The auxiliary air diffuser 30 is a general air diffuser such as a membrane type composed of a diffused membrane having a plurality of bubble discharge slits or a porous material such as ceramic. .

  The membrane separation facility 1 is provided with an auxiliary air supply device 31 that supplies air to each auxiliary air diffusion device 30. The auxiliary air supply device 31 includes an auxiliary air blower 32 and an auxiliary air supply pipe 33 connected between the auxiliary air blower 32 and each auxiliary air diffusion device 30.

Hereinafter, the operation of the above configuration will be described.
The treated water 2 supplied from the raw water supply system 35 into the treatment tank 3 is biologically treated by the activated sludge in the treatment tank 3 and is solid-liquid separated by the membrane units 7 and 8. The membrane permeated water that has passed through the filtration membrane 4 of the membrane units 7 and 8 is taken out from the treated water outlet system 19 as treated water 5 to the outside of the tank. Moreover, the solid content containing activated sludge is taken out of the tank from the sludge extraction system 29 as surplus sludge.

Hereinafter, the operation method of the membrane separation equipment 1 will be described.
A predetermined amount of air is diffused from the air diffuser 12 (hereinafter referred to as one air diffuser 12) of one of the plurality of membrane units 7 and 8 (an example of some membrane units). As a result, a large number of bubbles 37 are released from the one air diffuser 12 into the treated water 2 and floated, and an upward flow 38 of the treated water 2 is generated in the one membrane unit 7. Since this upward flow 38 is formed (generated) by the treated water 2 drawn in from the other membrane unit 8 (an example of the remaining membrane unit) adjacent through the lower region 23 and flows into the other membrane unit 8. Will generate a downward flow 39 of the water 2 to be treated. Thereby, the flow of the to-be-processed water 2 in both membrane units 7 and 8 is generated. Further, in a state where the downflow 39 is maintained, a small amount of air diffused from the air diffuser 13 of the other membrane unit 8 (hereinafter referred to as the other air diffuser 13) than the air diffuser of the one air diffuser 12. Do care.

  Thereby, the membrane surface of the filtration membrane 4 of one membrane unit 7 is washed by the upward flow 38 flowing through the flow path 34. Further, since the bubbles 37 released from the other air diffuser 13 into the descending flow 39 rise against the descending flow 39, the apparent ascending speed is reduced, and the bubbles 37 move in a wide range while drifting in the lateral direction. Surface. Thereby, the membrane surface of the filtration membrane 4 of the other membrane unit 8 is washed by the downward flow 39 flowing through the flow path 34, and also by the bubbles 37 and the local flow (turbulent flow) accompanying the movement of the bubbles 37. Washed extensively. Therefore, it can prevent that the deposit | attachment adhering to the corner | angular part etc. of the filtration membrane 4 remains without peeling.

  At this time, most (most) of the upward flow 38 rising to the vicinity of the water surface in the treatment tank 3 flows out from the inside of the wall body 9 to the outside of the wall body 9 through the communication portion 28. The treated water 2 outside the wall body 9 is drawn into the downward flow 39 near the water surface, and flows from the outside of the wall body 9 to the inside of the wall body 9 through the communication portion 28. Thereby, the to-be-processed water 2 in the processing tank 3 is mixed and stirred by the communication part 28 by the inner side and the outer side of the wall body 9, and the to-be-processed water 2 in the processing tank 3 is homogenized.

  At this time, since the communication portion 28 is formed over the entire upper periphery of the wall body 9, the water to be treated 2 can be mixed and stirred over a wide range through the communication portion 28, and the supply pump for circulating the water to be treated 2 And supply piping are not required, and operation costs can be reduced.

  In addition, by performing air diffusion from the auxiliary air diffuser 30 to the water to be treated 2 in the treatment tank 3, a sufficient amount of oxygen necessary for biological treatment can be supplied into the water to be treated 2. The auxiliary air diffuser 30 can be disposed at a position where oxygen is more efficiently dissolved by the water to be treated 2. For this reason, for example, there is an advantage that the auxiliary blower 32 can be operated with less aeration energy as compared with a method of increasing the amount of aeration of the blower 15 to promote the dissolution of oxygen.

  As described above, a predetermined amount of air diffused from one air diffuser 12 and a small amount of air diffused from the other air diffuser 13 than the amount of air diffused by one air diffuser 12 What is necessary is just to restrict | squeeze the opening degree of the valve | bulb 17 of the other aeration apparatus 13 rather than the opening degree of the valve | bulb 17 of one aeration apparatus 12. FIG.

  On the other hand, a predetermined amount of air is diffused from the other air diffuser 13 by narrowing the opening of the valve 17 of one air diffuser 12 more than the opening of the valve 17 of the other air diffuser 13. At the same time, it is possible to perform a small amount of air diffuser from one air diffuser 12 than the air diffuser of the other air diffuser 13. In this case, a large number of bubbles 37 are discharged from the other air diffuser 13 into the water to be treated 2 and float, and an upward flow 38 is generated in the other membrane unit 8, and a downward flow 39 is generated in the one membrane unit 7. appear. At this time, a small amount of air is diffused from one of the air diffusers 12 while maintaining the downward flow 39.

  Thereby, the membrane surface of the filtration membrane 4 of the other membrane unit 8 is washed by the upward flow 38. In addition, the membrane surface of the filtration membrane 4 of one membrane unit 7 is washed by the downward flow 39 and washed extensively by the bubbles 37.

  As described above, the first operation (see FIG. 1) in which the upflow 38 is generated in one membrane unit 7 and the downflow 39 is generated in the other membrane unit 8, and the upflow 38 is generated in the other membrane unit 8. And by alternately repeating the second operation for generating the downward flow 39 in one of the membrane units 7, the membrane surfaces of the filtration membranes 4 of the membrane units 7 and 8 alternate with the upward flow 38 and the downward flow 39, respectively. The film surface cleaning state for each of the film units 7 and 8 can be made uniform.

  Further, by periodically switching between the first operation and the second operation, the flow of the water to be treated 2 with respect to the membrane units 7 and 8 is reversed in the vertical direction, so that the fibrous form attached to the upper end of the membrane element 10 The adhering matter and the large adhering matter that cannot pass between the membrane elements 10 are peeled off by the upward flow 38, and the adhering matter adhering to the lower end portion of the membrane element 10 is peeled off by the downward flow 39.

  Similarly, by periodically switching between the first operation and the second operation, fibrous deposits such as stagnation entangled with the air diffusers 12 and 13 are also removed by the upward flow 38 and the downward flow 39. It is. Therefore, obstruction | occlusion of the air diffusion hole of the air diffusers 12 and 13 by a deposit | attachment is suppressed, and the uniform air diffusion in the membrane units 7 and 8 is ensured.

  The deposits thus peeled off or removed are discharged out of the tank from the sludge extraction system 29 together with the excess sludge. Thereby, the obstruction | occlusion by the sludge of the film surface accompanying the fall of the film surface washing | cleaning effect which a deposit | attachment causes is reduced.

  Further, the upward flow 38 is accelerated and rectified by the upper draft portion 20a of the wall body 9. For this reason, the flow rate of the upward flow 38 increases and the flow rate of the downward flow 39 also increases, and the cleaning effect of the membrane surface of the filtration membrane 4 is improved.

(Second Embodiment)
Next, a second embodiment will be described.
In the first embodiment described above, the wall body 9 has the bottom wall portion 21 as shown in FIG. 1. However, in the second embodiment, as shown in FIG. The body 45 does not have the bottom wall portion 21, and the bottom surface 3 a in the treatment tank 3 also serves as the bottom wall portion 21. That is, the wall body 45 has the side wall part 20 and the partition plate 25, and both upper and lower surfaces are open | released. The wall body 45 is installed at the central portion in the processing tank 3, and a sealing material 46 such as packing is provided between the lower end of the side wall portion 20 and the bottom surface in the processing tank 3.

According to this, the same operation and effect as the first embodiment described above can be obtained.
(Other embodiments)
In the first embodiment, as shown in FIG. 1, the bottom of the wall body 9 is in close contact with the bottom surface in the processing tank 3, but as a third embodiment, as shown in FIG. 5, A predetermined gap 48 may be provided between the bottom wall portion 21 of the wall body 9 and the bottom surface in the treatment tank 3. Although the wall body 9 is supported by the plurality of legs 49 and installed in the processing tank 3 in FIG. 5, the wall body 9 may be supported by being suspended from above.

  In the first and second embodiments, as shown in FIGS. 1 and 4, two membrane units 7 and 8 are arranged in the thickness direction A of the membrane element 10, but the number is limited to two. For example, as a fourth embodiment, four membrane units 7, 8, 50, 51 may be arranged as shown in FIG.

  In this case, a predetermined amount of air is diffused from the air diffusers 12 and 52 of one of the membrane units 7 and 50 adjacent to each other, and the air diffuser 12 is diffused from the air diffusers 13 and 53 of the other membrane units 8 and 51. , 52, an upward flow 38 is generated in one of the membrane units 7 and 50, and a downward flow 39 is generated in the other membrane units 8 and 51.

  On the other hand, a predetermined amount of air is diffused from the air diffusers 13 and 53, and a smaller amount of air is diffused from the air diffusers 12 and 52 than the air diffusers 13 and 53, thereby the other membrane unit 8. , 51, an upward flow 38 is generated, and a downward flow 39 is generated in one of the membrane units 7, 50.

  As described above, the first operation (see FIG. 6) in which the upflow 38 is generated in one of the membrane units 7 and 50 and the downflow 39 is generated in the other membrane units 8 and 51, and the other membrane units 8 and 51 is performed. The membrane surface of the filtration membrane 4 of each of the membrane units 7, 8, 50, 51 is generated by alternately repeating the second operation in which the upward flow 38 is generated and the downflow 39 is generated in one of the membrane units 7, 50. Can be washed alternately by the upward flow 38 and the downward flow 39, respectively.

Further, as a fifth embodiment, as shown in FIG. 7, a screen 55 (an example of a floating substance removing member) is provided at the upper end portion (that is, the communication portion 28) of the side wall body 20 of the wall body 9.
According to this, when the water 2 to be treated passes from the outside of the wall body 9 through the screen 55 of the communicating portion 28 and flows into the wall body 9, the suspended matter is captured by the screen 55, so Intrusion into the body 9 can be prevented.

  Further, as a sixth embodiment, as shown in FIG. 8, a plurality of concave portions 58 (an example of a communication portion) and convex portions 59 are formed on the upper portion of the side wall body 20 of the wall body 9. Protrudes upward from the surface of the water to be treated 2 in the treatment tank 3. The recess 58 is an opening that communicates with both the inside and outside of the wall body 9 in the water surface portion 27 of the water 2 to be treated. In addition, three membrane units 7, 8, 50 are arranged inside the wall body 9.

  In this case, a predetermined amount of air is diffused from the air diffuser 13 of the membrane unit 8 in the central portion, and a small amount of air is diffused from the air diffusers 12 and 52 at both ends than the air diffuser 13. An upward flow 38 is generated in the central membrane unit 8, and a downward flow 39 is generated in the membrane units 7 and 50 at both ends (see FIG. 8).

  On the other hand, a predetermined amount of air is diffused from the air diffusers 12 and 52 at both ends, and a smaller amount of air is diffused from the air diffuser 13 at the center than the air diffusers 12 and 52 at both ends. Ascending flow 38 is generated in the membrane units 7 and 50 in the central portion, and the descending flow 39 is generated in the membrane unit 8 in the central portion.

  As described above, the first operation in which the upward flow 38 is generated in the central membrane unit 8 and the downward flow 39 is generated in the membrane units 7 and 50 at both ends, and the upward flow 38 is generated in the membrane units 7 and 50 at both ends. And the second operation of generating the downward flow 39 in the central membrane unit 8 are alternately repeated, so that the membrane surface of the filtration membrane 4 of each of the membrane units 7, 8, and 50 is moved downward and downward respectively. It can be washed alternately with stream 39.

  At this time, a part of the upward flow 38 that has risen to the vicinity of the water surface in the treatment tank 3 flows out from the inside of the wall body 9 to the outside of the wall body 9 through the recess 58. The treated water 2 outside the wall body 9 is drawn into the downflow 39 near the water surface, and flows from the outside of the wall body 9 into the inside of the wall body 9 through the recess 58. Thereby, the to-be-processed water 2 in the processing tank 3 circulates through the communication part 28 to the inner side and the outer side of the wall body 9.

  Further, as a seventh embodiment, as shown in FIG. 9, a partition wall 61 is provided in the wall body 9, and the first processing chamber 62 and the second processing chamber 63 are formed in the wall body 9 by the partition wall 61. It is divided into. A plurality of (for example, two) membrane units 7 and 8 are disposed in the first processing chamber 62, and a plurality of (for example, two) membrane units 50 and 51 are disposed in the second processing chamber 63. Is arranged.

  According to this, in the first processing chamber 62, the first operation (see FIG. 9) in which the upflow 38 is generated in one membrane unit 7 and the downflow 39 is generated in the other membrane unit 8; By alternately repeating the second operation in which the upflow 38 is generated in the membrane unit 8 and the downflow 39 is generated in one of the membrane units 7, the membrane surfaces of the filtration membranes 4 of the membrane units 7 and 8 are respectively raised. The flow 38 and the downflow 39 can be alternately washed.

  Further, in the second processing chamber 63, the third operation (see FIG. 9) for generating the upward flow 38 in one membrane unit 50 and generating the downward flow 39 in the other membrane unit 51, and the other membrane unit. By alternately repeating the fourth operation in which the upward flow 38 is generated in 51 and the downward flow 39 is generated in one of the membrane units 50, the upward flow 38 is applied to the membrane surface of the filtration membrane 4 of each of the membrane units 50 and 51. And the downflow 39 can alternately be washed.

  In the present embodiment, the switching between the first operation and the second operation and the switching between the third operation and the fourth operation as described above are performed by the first processing chamber 62 and the second processing chamber 63. And can be done individually.

  Further, in each of the above embodiments, the membrane units 7, 8, 50, 51 are each configured with a single upper and lower stage (single stage), but may be configured with a plurality of upper and lower stages. For example, as an eighth embodiment, as shown in FIG. 10, the membrane units 7 and 8 are each composed of two upper and lower stages.

  Further, the upper end portion of the side wall body 20 of the wall body 9 protrudes upward from the water surface of the treated water 2 in the treatment tank 3, and the upper end portion of the side wall body 20 has a wall at a water surface portion 27 of the treated water 2. An opening 65 (an example of a communication part) communicating with both the inside and the outside of the body 9 is formed.

  According to this, a part of the ascending flow 38 rising to the vicinity of the water surface in the treatment tank 3 flows out from the inside of the wall body 9 to the outside of the wall body 9 through the opening 65. In addition, the water to be treated 2 outside the wall body 9 is drawn into the downward flow 39 in the vicinity of the water surface and flows into the wall body 9 from the outside of the wall body 9 through the opening 65. Thereby, the to-be-processed water 2 in the processing tank 3 circulates through the opening 65 to the inside and the outside of the wall body 9. The opening 65 does not necessarily need to include the water surface portion 27. If the opening 65 is positioned above the membrane units 7 and 8, the opening 65 is completely submerged in the treated water 2 below the water surface portion 27. May be.

  Moreover, in the said 1st Embodiment, as shown in FIG. 2, in the planar view, the inside of the wall body 9 is divided into the one division 41 and the other division 42 by the partition plate 25, and one division One membrane unit 7 is arranged in 41, and one membrane unit 8 is arranged in the other compartment 42. However, a plurality of membrane units 7 are arranged in one compartment 41, and in the other compartment 42 A plurality of membrane units 8 may be arranged. For example, as a ninth embodiment, as shown in FIG. 11, three membrane units 7 are arranged in parallel in one compartment 41, and three membrane units 8 are arranged in parallel in the other compartment 42. It may be.

  As a tenth embodiment, as shown in FIG. 12, the wall body 9 has a rectangular box-like structure with an open upper surface, and has a rectangular frame-shaped outer wall portion 67 and an outer wall portion 67. A rectangular frame-shaped inner wall portion 68 provided inside, and a bottom wall portion (not shown) provided between the lower end portion of the outer wall portion 67 and the lower end portion of the inner wall portion 68, It is installed in the central part in the processing tank 3.

  The upper and lower ends of the inner wall portion 68 are open. In the wall body 9, a plurality of membrane units 7, 8, 50, 51, 70 to 73 are installed so as to surround the inner wall portion 68. A partition plate 25 is provided between the membrane units 7, 8, 50, 51, and 70 to 73 adjacent to each other. Each partition plate 25 is attached between the outer wall portion 67 and the inner wall portion 68.

  According to this, for example, among the membrane units 7, 8, 50, 51, 70 to 73, the upward flow 38 is generated in one membrane unit 7, 50, 70, 72 adjacent to each other, and the other membrane unit 8, First operation for generating a downward flow 39 in 51, 71, 73, an upward flow 38 in the other membrane unit 8, 51, 71, 73 and a downward flow in one membrane unit 7, 50, 70, 72 By alternately repeating the second operation for generating 39, the membrane surfaces of the filtration membranes 4 of the membrane units 7, 8, 50, 51, 70 to 73 are alternately washed with the upflow 38 and the downflow 39, respectively. can do.

  As the eleventh embodiment, as shown in FIG. 13, a part of the wall body 9 is constituted by a part of the processing tank 3. That is, the wall body 9 includes a pair of side wall portions 9a and 9b facing each other in one direction A (for example, the thickness direction of the membrane element 10) and another direction B (for example, the width direction of the membrane element 10) orthogonal to the one direction A. ) Have a pair of opposing side wall portions 9c and 9d. Among these, the side wall parts 9 a to 9 c are constituted by a part of the processing tank 3, and the side wall part 9 d is provided between a pair of opposing wall surfaces of the processing tank 3.

  In the upper part of the side wall portion 9 d of the wall body 9, a communication portion 28 for taking the treated water 2 into and out of the wall body 9 at the water surface portion 27 in the treatment tank 3 is provided. That is, the side wall portion 9 d is submerged in the water to be treated 2 in the treatment tank 3, and the communication portion 28 is formed between the upper end of the side wall portion 9 d and the water surface portion 27.

A plurality of (for example, two) membrane units 7 and 8 are installed in the wall body 9, and a partition plate 25 is provided between adjacent membrane units 7 and 8.
According to this, the first operation (see FIG. 13) in which the upflow 38 is generated in one membrane unit 7 and the downflow 39 is generated in the other membrane unit 8, and the upflow 38 is generated in the other membrane unit 8. And by alternately repeating the second operation for generating the downward flow 39 in one of the membrane units 7, the membrane surfaces of the filtration membranes 4 of the membrane units 7 and 8 alternate with the upward flow 38 and the downward flow 39, respectively. Can be washed.

  At this time, a part of the upward flow 38 rising to the vicinity of the water surface in the treatment tank 3 flows out from the inside of the wall body 9 to the outside of the wall body 9 through the communication portion 28 as shown by an arrow F1 in FIG. To do. Further, the water 2 to be treated outside the wall body 9 is drawn into the downward flow 39 in the vicinity of the water surface, and passes through the communicating portion 28 from the outside of the wall body 9 as shown by an arrow F2 in FIG. Flows inward. Thereby, the to-be-processed water 2 in the processing tank 3 circulates through the communication part 28 to the inner side and the outer side of the wall body 9.

  As a twelfth embodiment, when operating the membrane separation facility 1, an operation is performed in which air is diffused from the diffuser of some of the plurality of membrane units and is not diffused from the remaining membrane units. A method is mentioned.

  For example, in the membrane separation facility 1 shown in FIG. 1 of the first embodiment, an air diffuser 12 (one of the plurality of membrane units 7, 8) (one example of some membrane units) Hereafter, a predetermined amount of air is diffused from one air diffuser 12), and the air diffuser 13 of the other membrane unit 8 (an example of the remaining membrane unit) (hereinafter referred to as the other air diffuser 13). Do not aerate from.

As a result, an upward flow 38 of the water to be treated 2 is generated in one membrane unit 7, and this upward flow 38
When the treated water 2 is drawn into the lower region 23, a downward flow 39 of the treated water 2 is generated in the other adjacent membrane unit 8.

  Thereby, the membrane surface of the filtration membrane 4 of one membrane unit 7 is washed by the upward flow 38 flowing through the flow path 34. Further, even if no air is diffused from the other air diffuser 13, the membrane surface of the filtration membrane 4 of the other membrane unit 8 is washed to some extent by the downward flow 39 flowing through the flow path 34.

  On the other hand, a predetermined amount of air may be diffused from the other air diffuser 13 and not diffused from one air diffuser 12. In this case, since the upward flow 38 is generated in the other membrane unit 8 and the downward flow 39 is generated in the one membrane unit 7, the membrane surface of the filtration membrane 4 of the other membrane unit 8 is increased in the flow path 34. Washed by stream 38. Further, even if air is not diffused from one air diffuser 12, the membrane surface of the filtration membrane 4 of one membrane unit 7 is washed to some extent by the downflow 39 flowing through the flow path 34.

In addition, the operation method of the twelfth embodiment may be applied to the membrane separation equipment 1 in each of the embodiments other than the first embodiment.
In the fourth to tenth embodiments, the wall body 9 having the bottom wall portion 21 is provided. Instead of the wall body 9, the bottom wall portion 21 as described in the second embodiment is used. You may provide the wall body 45 which does not have.

  In the first embodiment, as shown in FIG. 1, a valve 17 such as an automatic flow control valve is used in the air supply device 14, but as a thirteenth embodiment, as shown in FIG. Three-way automatic valves 75a and 75b may be used for the air supply device 14.

  That is, the air supply device 14 is provided in the air blower 15, the plurality of first air supply tubes 74 a and 74 b connected between the air blower 15 and each of the air diffusion devices 12 and 13, and the first air supply tubes 74 a and 74 b. The three-way automatic valves 75a and 75b, the second three-way automatic valves 75a and 75b, the second supply pipes 76a and 76b connected between the first supply pipes 74a and 74b, and the second supply pipes 76a and 76b. And throttle valves 77a and 77b provided in the

  The first outlet P1 of one of the three-way automatic valves 75a communicates with one of the air diffusers 12 through one of the first air supply pipes 74a. One end of one second air supply pipe 76a is connected to the second outlet P2 of one three-way automatic valve 75a, and the other end is connected to the downstream side of the first air supply pipe 74a.

  Similarly, the first outlet P1 of the other three-way automatic valve 75b communicates with the other air diffuser 13 through the other first air supply pipe 74b. One end of the other second air supply pipe 76b is connected to the second outlet P2 of the other three-way automatic valve 75b, and the other end is connected to the downstream side of the first air supply pipe 74b.

  The one and the other three-way automatic valves 75a and 75b respectively have a first flow direction Fa that flows the air supplied from the blower 15 from the inlet P0 side to the first outlet P1 side and the second outlet P2 from the inlet P0 side. The flow direction is switched to one of the second flow directions Fb flowing to the side. Moreover, the opening degree of both the throttle valves 77a and 77b is set to such an opening degree that the amount of diffused air is kept small.

Hereinafter, the operation of the above configuration will be described.
For example, a predetermined amount of air is diffused from one air diffuser 12 to generate an upward flow 38, and a lower amount of air is diffused from the other air diffuser 13 to a predetermined amount to generate a downward flow 39. In this case, one of the three-way automatic valves 75a is switched, the air supplied from the blower 15 to one of the first supply pipes 74a is flowed in the first flow direction Fa, and the other three-way automatic valve 75b is switched from the blower 15. The air supplied to the other first air supply pipe 74b is caused to flow in the second flow direction Fb.

  As a result, the air discharged from the blower 15 does not flow through the one second air supply pipe 76a, is discharged from the one air diffuser 12 through the one first air supply pipe 74a in a predetermined amount, and the other air After flowing through the other second air supply pipe 76b from the upstream side of the first air supply pipe 74b and being throttled by the other throttle valve 77b, it flows into the downstream side of the other first air supply pipe 74b again and flows into the other air diffuser. 13 is released in small amounts. As a result, an upward flow 38 is generated in one of the diffusers 12 and a downward flow 39 is generated in the other diffuser 13.

  In addition, a predetermined amount of air is diffused from the other air diffuser 13 to generate an upward flow 38, and a lower amount of air is diffused from the one air diffuser 12 than the predetermined amount to generate a downward flow 39. In this case, one of the three-way automatic valves 75a is switched so that the air supplied from the blower 15 to the first first supply pipe 74a flows in the second flow direction Fb, and the other three-way automatic valve 75b is switched from the blower 15. The air supplied to the other first air supply pipe 74b is caused to flow in the first flow direction Fa.

  As a result, the air discharged from the blower 15 is released from the other air diffuser 13 by a predetermined amount through the other first air supply pipe 74b, and one of the air is discharged from the upstream side of the first air supply pipe 74a. After flowing through the second air supply pipe 76a and being throttled by one throttle valve 77a, it flows into the downstream side of the first air supply pipe 74a again and is released from the one air diffuser 12 in a small amount. As a result, an upflow 38 is generated in the other diffuser 13 and a downflow 39 is generated in the one diffuser 12.

  In each of the above embodiments, the partition plate 25 is submerged below the surface of the water to be treated 2 and is located below the upper end of the wall body 9, and is an upper region of the adjacent membrane units 7, 8, 50, 51. 22 communicate with each other through the water 2 to be treated. As shown in FIGS. 15 and 16, the upper end portion of the partition plate 25 is located above the water surface of the water 2 to be treated. It may extend.

  For example, when an upflow 38 is formed in one adjacent membrane unit 7 and a downflow 39 is formed in the other membrane unit 8, the entire amount of the upflow 38 once passes from the one membrane unit 7 to the communication portion 28. After flowing out to the outside of the wall body 9, it flows into the other membrane unit 8 from the outside of the wall body 9 through the communication portion 28. For this reason, the to-be-processed water 2 is mixed and stirred over the whole processing tank 3, and mixing and stirring of the to-be-processed water 2 are accelerated | stimulated. In addition, the upper end part of the partition plate 25 may protrude on the water surface of the to-be-processed water 2, or may be immersed under the water surface.

  In each of the above embodiments, the membrane units 7, 8, 50, 51 are partitioned by the partition plate 25, but the membrane case 11 of each membrane unit 7, 8, 50, 51 corresponds to the partition plate 25. When fulfilling the function, the partition plate 25 may not be provided.

  Furthermore, even if each membrane unit 7, 8, 50, 51 is not provided with the membrane case 11 and the partition plate 25 is not provided, each membrane unit 7, 8, 50, 51 has a purpose. Ascending flow 38 and descending flow 39 can be formed.

  In each of the above-described embodiments, the membrane units 7, 8, 50, 51, the wall body 9, and the partition plate 25 are identified as shown in FIGS. In addition, gaps are formed between the membrane units 7, 8, 50, 51 and the wall body 9, and between the membrane units 7, 8, 50, 51 and the partition plate 25. Such a gap is preferably as narrow as possible or eliminated.

  In each of the above embodiments, the wall body 9 and the membrane case 11 of each membrane unit 7, 8, 50, 51 are individually provided, but only necessary portions such as the lower opening and the upper draft portion 20a are added. Thus, the membrane case 11 may be configured to also serve as a part of the wall body 9.

  In each of the above embodiments, the membrane units 7, 8, 50, 51 including the plate-like membrane element 10 are used. However, the membrane element 10 is not limited to the plate shape, for example, a hollow fiber membrane. Any type of membrane element 10 may be used as long as the surface of the separation membrane is washed with a fluid flow, such as a type or a tubular membrane type.

1 Membrane separation equipment 2 Water to be treated (liquid to be treated)
3 treatment tank 4 filtration membrane 5 treated water (treatment liquid)
6 Membrane separation device 7, 8, 50, 51 Membrane unit 9 Wall body 12, 13, 52, 53 Air diffuser 22 Upper region 23 Lower region 25 Partition plate (partition member)
27 Water surface part (liquid surface part)
28 Communication part 30 Auxiliary air diffuser 38 Up flow 39 Down flow

Claims (6)

A treatment tank for storing the treatment liquid, and a membrane separation device for obtaining a treatment liquid that is immersed in the treatment liquid in the treatment tank and that is transmitted through the filtration membrane,
The membrane separation apparatus has a plurality of membrane units arranged adjacent to each other in the horizontal direction, and a wall body that partitions between the plurality of membrane units and the treatment tank,
Above the membrane unit of the wall body, a communication part for taking in and out the liquid to be treated into and out of the wall body is provided,
The lower regions of adjacent membrane units communicate with each other via the liquid to be processed.
A membrane separation facility characterized in that each membrane unit has a diffuser at the bottom. The membrane separation facility according to claim 1, wherein the upper region of adjacent membrane units is partitioned by a partition member. The membrane separation facility according to claim 1 or 2, wherein an auxiliary air diffuser is provided inside the treatment tank and outside the wall body. A membrane separation device that obtains a treatment liquid that is immersed in a treatment liquid in a treatment tank and that passes through a filtration membrane,
A plurality of membrane units arranged adjacent to each other in the horizontal direction, and a wall body that partitions between the plurality of membrane units and the treatment tank,
Above the membrane unit of the wall body is provided with a communication part for taking the treatment liquid in and out of the wall body in and out of the wall body,
The lower regions of adjacent membrane units communicate with each other via the liquid to be processed.
A membrane separation device, wherein each of the membrane units is provided with an air diffuser at the bottom. The operation method of the membrane separation equipment according to any one of claims 1 to 3,
Aeration is performed from the diffuser of some of the plurality of membrane units to generate an upward flow of the liquid to be processed in some of the membrane units and a downward flow of the liquid to be processed in the remaining membrane units. Is generated,
A method for operating a membrane separation facility, characterized in that a small amount of air is diffused from the air diffuser of the remaining membrane unit while maintaining a downward flow. The operation method of the membrane separation equipment according to any one of claims 1 to 3,
A method for operating a membrane separation facility, characterized in that air is diffused from an air diffuser of a part of the plurality of membrane units and is not diffused from the air diffuser of the remaining membrane units.

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