WO2023181933A1

WO2023181933A1 - Filtration system and filtration processing equipment

Info

Publication number: WO2023181933A1
Application number: PCT/JP2023/008743
Authority: WO
Inventors: 寛野口; 輝武丹羽; 彰利中川
Original assignee: 株式会社明電舎
Priority date: 2022-03-23
Filing date: 2023-03-08
Publication date: 2023-09-28
Also published as: JP2023140572A; JP7338728B1

Abstract

This filtration system comprises a plurality of filtration membrane units in which a filtrate taken into the interior of the filtration membrane flows along the lengthwise direction of the filtration membrane, an accommodation space for accommodating the filtrate discharged from each of the plurality of filtration membrane units, an upper connecting flow passage (50) connecting an upper portion of the accommodation space to an external space above the accommodation space, and a lower connecting flow passage (51) connecting a lower portion of the accommodation space to an external space below the accommodation space, said filtration system being equipped with a guiding tube 150, which comprises a tubular member in which through-holes 152 are provided in the peripheral wall, is connected to the upper connecting flow passage 50 and the lower connecting flow passage 51 and guides the flow of liquid between the upper connecting flow passage 50 and the lower connecting flow passage 51, and into the interior of which the filtrate in the accommodation space is taken in through the through-holes 152.

Description

Filtration system and filtration treatment equipment

The present invention relates to a filtration system and filtration treatment equipment.

Conventionally, there have been provided a plurality of filtration membrane units through which the filtrate taken into the filtration membrane flows along the longitudinal direction of the filtration membrane, a storage space for accommodating the filtrate discharged from each of the plurality of filtration membrane units, and an upper communication channel. A filtration system is known that includes a lower communication channel and a lower communication channel.

For example, the membrane separation device described in Patent Document 1 includes a plurality of membrane modules stacked in multiple stages. A membrane module as a filtration system includes a plurality of membrane elements as filtration membrane units and a water collection case. The water collection case is provided with a storage space for accommodating filtrate discharged from each of the plurality of membrane elements, an upper connecting section serving as an upper communicating channel, and a lower connecting section serving as a lower communicating channel. The upper connection path connects the upper part of the accommodation space to the external space above the accommodation space. Moreover, the lower connecting path connects the lower part of the accommodation space to the external space below the accommodation space.

In a filtration system, the filtrate collected in the storage space from each of the plurality of membrane elements is discharged upward from the upper connection path, and then passes through the lower connection path of the upper membrane module to the upper storage space. leading to. Alternatively, after being discharged downward from the lower connecting path, it reaches the lower housing space via the upper connecting path of the membrane module arranged in the lower stage. In this manner, the membrane separator collects the filtrate that has been filtered by the plurality of membrane modules while flowing from the lower stage to the upper stage, or collects the filtrate while flowing from the upper stage to the lower stage.

JP2012-148230A

In a membrane separation device having such a configuration, there is a problem in that the energy efficiency of the power source decreases due to an increase in flow path resistance due to turbulence generated within the housing space of each membrane module.

The present invention has been made in view of the above background, and it is an object of the present invention to provide a filtration system and filtration processing equipment that can suppress a decrease in energy efficiency caused by turbulence generated within a storage space.

In order to achieve the above object, one aspect of the present invention includes a plurality of filtration membrane units through which the filtrate taken into the inside of the filtration membrane flows along the longitudinal direction of the filtration membrane, and a plurality of filtration membrane units that flow from each of the plurality of filtration membrane units. an accommodation space that accommodates the filtrate to be discharged; an upper communication channel that communicates the upper part of the accommodation space with an external space above the accommodation space; and the lower part of the accommodation space that communicates with an external space below the accommodation space. A filtration system comprising a lower communication flow path communicating with the upper communication flow path, the system comprising a tubular member having a through hole arranged in a peripheral wall, and communicating with the upper communication flow path and the lower communication flow path with the upper communication flow path. The device is characterized in that it includes a guide tube that takes the filtrate in the storage space into itself through the through hole while guiding the flow of liquid to and from the lower communication channel.

According to the present invention, there is an excellent effect of suppressing a decrease in energy efficiency caused by turbulence generated within the accommodation space.

1 is a diagram showing a schematic configuration of a water treatment facility including a filtration system according to an embodiment. It is a perspective view showing a filtration membrane unit concerning an embodiment. It is a sectional view showing a longitudinal section of a suction side socket of the same filter membrane unit. It is a side view showing the same filter membrane unit from the side. FIG. 1 is a perspective view showing a filtration system according to an embodiment. It is an exploded perspective view showing the same filtration system. It is a perspective view showing a water collection cassette of the holding body concerning an embodiment. It is a perspective view showing filtration processing equipment concerning an embodiment. It is a perspective view which shows the upper water collection cassette and the lower water collection cassette arranged in multiple stages in the same filtration processing equipment, and the connecting pipe which connects these cassettes. It is a perspective view showing a guide tube. FIG. 3 is a perspective view for explaining the flow of treated water in the storage space in an upper stage transfer method in which treated water is transported toward the upper stage. It is a perspective view for explaining the flow of treated water in a storage space in a lower tier transfer method for transferring treated water toward a lower tier. It is a sectional view showing a longitudinal section of two water collection cassettes stacked one above the other in the filtration treatment equipment according to the example, together with a cross section of a connecting pipe. FIG. 11 is a cross-sectional view showing a cross section of the connecting pipe in a larger scale than that shown in FIG. 10;

Hereinafter, one embodiment of a filtration treatment facility to which the present invention is applied will be described using each figure. In the embodiments, structures and elements other than the main parts of the present invention will be simplified or omitted in order to make the description easier to understand. Further, in each figure, the same elements are given the same reference numerals. Note that the shapes, dimensions, etc. of each element shown in each figure are shown schematically, and do not represent actual shapes, dimensions, etc.

FIG. 1 is a diagram showing a schematic configuration of a water treatment facility including filtration treatment equipment according to an embodiment. This water treatment facility includes a raw water tank 1, a filtered water tank 2, a treated water tank 3, a control device 4, a raw water pump 5, a first water level sensor 6, a raw water transfer pipe 7, a treated water transfer pipe 8, a suction pump 9, and a first water level sensor 6. A second water level sensor 11, a third water level sensor 12, etc. are provided. The water treatment facility also includes a blower 13, an air supply pipe 14, a pedestal 15, a filtration treatment facility 20, a bubble generator 90, and the like.

In the raw water tank 1, raw water (pre-treatment water) _W1 as a liquid is stored. A first water level sensor, such as an ultrasonic sensor installed in the raw water tank 1, detects the water level (water surface height) of the raw water _W1 in the raw water tank 1, and sends the detection result to the control device 4 as a water level signal. Send. A raw water pump 5 installed in the raw water tank 1 sucks and discharges the raw water _W1 in the raw water tank 1, and sends it to the filtration treatment tank 2 through the raw water transfer pipe 7. Although a submersible pump is illustrated as the raw water pump 5, a land pump may also be used.

The filtration treatment water tank 2 is a water tank made of reinforced concrete. In the filtration treatment water tank 2, a filtration treatment equipment 20 and a bubble generator 90 are installed. The filtration treatment equipment 20 and the bubble generator 90 are supported by the pedestal 15. The pedestal 15 supports the bubble generator 90 in such a manner that it is positioned directly below the filtration treatment equipment 20 . Each of the filtration equipment 20 and the bubble generator 90 is immersed in the raw water _W1 in the filtration water tank 2.

The blower 13 discharges air as a gas sucked through the suction port to the air supply pipe 14 through the discharge port. The air discharged into the air supply pipe 14 is supplied to the bubble generator 90. The bubble generator 90 emits air supplied from the air supply pipe 14 upward as bubbles. The released air bubbles rise in the raw water _W1 while contacting a plurality of filter membranes mounted on the filtration treatment equipment 20. At this time, the bubbles cause the solid matter adhering to the surface of the filtration membrane to separate from the surface of the filtration membrane. This separation suppresses clogging of the filtration membrane.

The third water level sensor 12 installed in the filtered water tank 2 detects the water level of the raw water _W1 in the filtered water tank 2, and transmits the detection result to the control device 4 as a water level signal.

The suction pump 9 sucks raw water W ₁ in the filtered water tank 2 via the treated water transfer pipe 8 and a plurality of filter membranes, which will be described later, mounted in the filtering equipment 20 . The sucked raw water W ₁ is filtered by a filter membrane to become treated water W ₂ , and then sent to the treated water tank 3 through the treated water transfer pipe 8 . The second water level sensor 11 set in the treated water tank 3 detects the water level of the treated water W2 in the treated water tank 3, and transmits the detection result to the control device 4 as a water level signal.

Note that instead of the suction pump 9, a pump that generates suction force using water head pressure may be used. The means of suction is not particularly limited.

When the water level in the treated water tank 3 has not reached the upper limit and predetermined operation execution conditions are met, the control device 4 operates the suction pump 9 and the blower 13 to perform the filtration process on the raw water _W1. Execute. However, even if the operation execution conditions are met, if the water level of the raw water W ₁ in the raw water tank 1 is below the lower limit, or if the water level of the raw water W ₁ in the filtered water tank 2 is below the lower limit. In this case, the control device 4 stops execution of the filtration process.

The filtration treatment equipment 20 includes a plurality of filtration systems (described in detail later) according to the embodiment. Each filtration system includes a plurality of filtration membrane units (described in detail later) according to embodiments.

FIG. 2 is a perspective view showing the filtration membrane unit 21 according to the embodiment. The filtration membrane unit 21 includes a flat filtration membrane 22 . Examples of the material for the filter membrane 22 include organic materials such as PVDF (polyvinylidene fluoride) and PVC (polyvinyl chloride). Further, as the material of the filter membrane 22, a ceramic whose main component is alumina, silicon carbide, etc. may be used. The filtration membrane 22 of the filtration membrane unit 21 according to the embodiment is made of a ceramic membrane.

When the above-mentioned suction pump (9 in FIG. 1) operates, suction force is applied to the filtration membrane 22 along the longitudinal direction of the filtration membrane 22. In the filtration system according to the embodiment, a suction force is applied to the filtration membrane 22 from one side in the longitudinal direction of the filtration membrane 22 (the right side in the left-right direction in FIG. 4, which will be described later). That is, one side of the filter membrane 22 in the longitudinal direction is a suction side to which suction force is applied. The other side in the longitudinal direction of the filtration membrane 22 (the left side in the left-right direction in FIG. 4, which will be described later) is a shielding side that shields the suction force applied to the filtration membrane 22.

In addition to the above-mentioned filtration membrane 22, the filtration membrane unit 21 includes a suction side socket 23 and a shielding side socket 24. The suction side socket 23 serving as a socket in the present invention is fixed to one end of the filtration membrane 22 in the longitudinal direction in order to hold the filtration membrane 22 on one side (suction side) in the longitudinal direction. The shield-side socket 24 is fixed to the other longitudinal end of the filter membrane 22 in order to hold the filter membrane 22 on the other longitudinal side (shield side). Each of the suction side socket 23 and the shielding side socket 24 is fixed to the filtration membrane 22 and extends in the lateral direction of the filtration membrane 22 (in the embodiment, the vertical direction along the direction of gravity).

FIG. 3 is a sectional view showing a longitudinal section of the suction side socket 23. The suction side socket 23 includes a socket main body 23a. The socket main body 23a has a recess 23d into which one longitudinal end of the filtration membrane (22 in FIG. 2) is inserted, and a channel 23e extending in the extending direction of the socket main body 23a while communicating with the recess 23d. Be prepared.

The socket main body 23a completely covers the circumferential surface of the filtration membrane (22 in FIG. 2), which is composed of a front surface, a back surface, and two side surfaces at one longitudinal end of the filtration membrane (22 in FIG. 2), by the inner peripheral surface of the recess 23d. Cover all around. The inner circumferential surface of the recess 23d covers the entire circumferential surface of one end of the filter membrane (22) in the longitudinal direction, thereby preventing the end from wobbling within the recess 23d.

In addition to the socket body 23a described above, the suction side socket 23 includes a first protrusion 23b and a second protrusion 23c. Each of the first protruding body 23b and the second protruding body 23c is located on the outside (on the right side in FIG. 3) of the socket main body 23a in the longitudinal direction (left-right direction in FIG. 3) of the filtration membrane (22 in FIG. 2). , are lined up along the extending direction (vertical direction in FIG. 3) of the socket body 23a.

Each of the first protruding body 23b and the second protruding body 23c extends from one end surface of the socket main body 23a (right side in FIG. 3) to one side in the longitudinal direction (left-right direction in FIG. 3) of the filtration membrane (22). protrude towards.

In such a configuration, when each of the first protrusion 23b and the second protrusion 23c is inserted into an insertion hole provided in a holder (not shown), one longitudinal end of the filtration membrane unit (21) It is positioned with respect to the holding body and is held by the holding body. The area of the outer circumferential surface of the first protruding body 23b is much smaller than the area of the outer circumferential surface of the socket main body 23a. Furthermore, the area of the outer circumferential surface of the second protrusion 23c is also much smaller than the area of the outer circumferential surface of the socket body 23a. Therefore, even if the clearance between the outer periphery of the first protrusion 23b and the inner periphery of the insertion hole described above and the clearance between the outer periphery of the second protrusion 23c and the inner periphery of the insertion hole described above are almost eliminated, they are It is possible to easily insert each of the protrusions (23b, 23c) into individual insertion holes. When the clearance is set in this manner, wobbling at one end of the filtration membrane unit (21) in the longitudinal direction is prevented. Therefore, according to the filtration membrane unit (21) according to the embodiment, it is possible to suppress the occurrence of damage to the filtration membrane (22) due to rattling at one end in the longitudinal direction of the filtration membrane unit.

The structure of each of the first protruding body 23b and the second protruding body 23c is a tubular structure having a hollow (23b-1, 23c-1). Each hollow (23b-1, 23c-1) in the first protrusion 23b and the second protrusion 23c communicates with the channel 23e of the socket body 23a. Further, the hollows (23b-1, 23c-1) in the first protruding body 23b and the second protruding body 23c are located at both ends of the protruding bodies (23b, 23c) in the extending direction (left-right direction in FIG. 3). is open. Of the two openings in the hollow 23b-1 of the first protrusion 23b, the opening on one side (the right side in FIG. 3) in the extending direction (left-right direction in FIG. 3) of the first protrusion 23b is inside the flow path 23e. The first outlet 23b-2 is a discharge port for discharging the treated water (W ₂ in FIG. 1). Further, among the two openings in the hollow 23c-1 of the second protrusion 23c, the opening on one side (the right side in FIG. 3) in the extending direction (left-right direction in FIG. 3) of the second protrusion 23c is a flow path. The second outlet 23c-2 is a discharge port for discharging the treated water in the second outlet 23e.

The hollow 23b-1 of the first protruding body 23b has an opening 23b-3 on the other side (the left side in FIG. 3) in the extending direction (left-right direction in FIG. 3) of the first protruding body 23b among its two openings. It communicates with the flow path 23e through. Further, the hollow 23c-1 of the second protrusion 23c is the opening 23c on the other side (the left side in FIG. 3) of the two openings of the second protrusion 23c in the extending direction (left-right direction in FIG. 3). -3 and communicates with the flow path 23e.

When the suction pump (9 in FIG. 1) operates, a suction force due to negative pressure is generated in each of the hollow 23b-1 of the first protruding body 23b and the hollow 23c-1 of the second protruding body 23c. Due to this suction force, the treated water in the channel 23e of the socket body 23a is sucked toward the interior of the hollow 23b-1 of the first protrusion 23b and the hollow 23c-1 of the second protrusion 23c.

FIG. 4 is a side view showing the filtration membrane unit 21 from the side. The shield-side socket 24 of the filtration membrane unit 21 includes a socket main body 24a and two protrusions 24b. The socket main body 24a includes a recess (not shown) into which the other end (left side in FIG. 4) of the filter membrane 22 in the longitudinal direction (left-right direction in FIG. 4) is inserted. Note that the socket main body 24a does not include a flow path communicating with the above-mentioned recess. The suction force applied to the filtration membrane 22 is blocked on the other longitudinal side of the filtration membrane 22 by the shielding side socket 24 .

Each of the two protrusions 24b in the shielding side socket 24 is located outside (on the left side in FIG. 4) of the socket body 24a in the longitudinal direction of the filtration membrane 22 (the left-right direction in FIG. 4), and extends from the socket body 24a. They are lined up along the current direction (vertical direction in FIG. 4).

Hereinafter, the first outlet provided on the first protruding body 23b (23b-2 in FIG. 3) and the second outlet provided on the second protruding body 23c (second outlet 23c-2 in FIG. 3) will be collectively referred to as "suction side". ``Two outlets of socket 23''. When the diameter of the discharge port is set to a predetermined value and the amount of filtrate per unit time by the filtration membrane (22, 122) is set to a predetermined value, the conditions for the flow rate of treated water per unit time passing through the discharge port As such, it is necessary to adopt the following conditions. That is, the amount of treated water flowing into the outlet of the filtration membrane unit 121 according to the first comparative example is approximately equal to the amount of treated water flowing into each of the "two outlets of the suction side socket 23" according to the embodiment. The condition is to set it twice. Under such conditions, the flow path resistance of the treated water in the filtration membrane unit 21 is made smaller than in the first comparative example, compared to the configuration described in Patent Document 1, which has only one discharge port (filtrate outlet). Therefore, the power of a suction power machine such as a suction pump (9 in FIG. 1) can be made smaller, and energy saving can be achieved.

Unlike the embodiment shown in FIG. 3, each of the first outlet (23b-2 in FIG. 3) and the second outlet (23c-2 in FIG. 3) (hereinafter, this arrangement will be referred to as peripheral arrangement). However, as shown in FIG. 3, the first outlet 23b-2 and the second outlet 23c-2 are arranged on the tip surface of the protrusion (23b, 23c) (hereinafter, this arrangement is referred to as the tip surface arrangement). ) is more desirable. This is due to the reason explained below. That is, in the circumferential arrangement, the flow of treated water in the hollows (23b-1, 23c-1) of the protrusions (23b-2, 23c-2) is directed to the discharge ports (first outlet 23b-2, second outlet It is necessary to change direction at an angle of about 90 degrees just before reaching the exit 23c-2). This increases the flow path resistance of the filtration membrane unit 21. On the other hand, in the distal end arrangement, the flow direction of the treated water in the hollows (23b-1, 23c-1) of the protrusions (23b-2, 23c-2) and the discharge port (first outlet 23b-2) , the flow direction of the treated water when passing through the second outlet 23c-2) is the same direction. Therefore, unlike the circumferential arrangement, there is no need to change the direction of the flow of the treated water in the hollows (23b-1, 23c-1), so the flow path resistance is reduced compared to the circumferential arrangement. be able to.

FIG. 5 is a perspective view showing the filtration system 31 according to the embodiment. The filtration system 31 includes a plurality of filtration membrane units 21 and a holder 40 that holds the plurality of filtration membrane units 21. The shape of the holder 40 is a frame, and the holder 40 holds a plurality of filtration membrane units 21 within the frame. The holding body 40 also includes a water collection cassette 41, a blind cassette 60, a first side cover 65, and a second side cover 66.

FIG. 6 is an exploded perspective view showing the filtration system 31 according to the embodiment. The holder (40 in FIG. 5) is composed of a flat rectangular parallelepiped-shaped water collection cassette 41, a flat plate-shaped first side cover 65, a flat rectangular parallelepiped-shaped blind cassette 60, and a flat plate-shaped second side cover 66. It is formed by combining the shapes. Unlike the state shown in the figure, in a state where a plurality of filtration membrane units 21 are not present, the water collection cassette 41 and the blind cassette 60 face each other. Additionally, in the above state, the first side cover 65 and the second side cover 66 face each other in a direction perpendicular to the direction in which the water collection cassette 41 and the blind cassette 60 face each other.

Each of the water collection cassette 41 and the blind cassette 60 is arranged in such a manner that its longitudinal direction is aligned with the direction in which the first side cover 65 and the second side cover 66 face each other. On the other hand, each of the first side cover 65 and the second side cover 66 is arranged such that its longitudinal direction is aligned with the direction in which the water collection cassette 41 and the blind cassette 60 face each other.

FIG. 7 is a perspective view showing the water collection cassette 41 of the holder (40 in FIG. 5). The water collection cassette 41 includes a top plate 42, a bottom plate 45, a first long side plate 43, a second long side plate 44, a first short side plate 46 shorter than the long side plates (43, 44), and a first short side plate 46, which is shorter than the long side plates (43, 44). Two short side plates 47 are combined to form a flat rectangular parallelepiped shape. The top plate 42 and the bottom plate 45 face each other. In the water treatment facility, as shown in the figure, the water collection cassette 41 is arranged in such a manner that the top plate 42 and the bottom plate 45 are arranged vertically along the direction of gravity.

Each of the first long side plate 43 and the second long side plate 44 is arranged in such a manner that its longitudinal direction is along the short side direction of the first short side plate 46 and the second short side plate 47, respectively. On the other hand, each of the first short side plate 46 and the second short side plate 47 is arranged in such a manner that its longitudinal direction is aligned with the direction in which the top plate 42 and the bottom plate 45 face each other.

A first fixing portion 48 protruding from the front surface is provided on the front surface of the first short side plate 46. Furthermore, a second fixing portion 49 is provided on the front surface of the second short side plate 47 and protrudes from the front surface.

Hereinafter, the frame structure of the frame-shaped holder (40 in FIG. 5) will be simply referred to as a "frame." The first elongated side plate 43 is located inside the "frame" than the second elongated side plate 44. The first elongated side plate 43 functions as a side plate that holds one longitudinal end of the filtration membrane unit (21 in FIG. 6).

The first elongated side plate 43 has an insertion hole into which one of the first protrusion (23b in FIG. 3) and the second protrusion (23c in FIG. 3) is inserted, and the first and second protrusion. A plurality of hole pairs are provided in which one of the protruding bodies is not inserted into the insertion hole and the other is inserted into the insertion hole. In each of the plurality of hole pairs, the distance between the two insertion holes is the same.

As shown in FIG. 6, the two insertion holes of the hole pair are arranged along the short direction of the first long side plate 43 (vertical direction in FIG. 6). One of the first protruding body 23b and the second protruding body 23c is inserted into one of the two insertion holes of the hole pair, and the other protruding body is inserted into the other insertion hole.

As shown in FIG. 2, each of the two protrusions 24b of the shielding socket 24 has a square or rectangular parallelepiped shape. The two protrusions 24b are for positioning the other longitudinal end of the filtration membrane unit (21 in FIG. 6) in the blind cassette (60 in FIG. 6) and holding the other end in the blind cassette. It is.

In the suction side socket 23, each of the two protrusions (23b, 23c) formed integrally with the socket main body 23a has a tubular shape.
Hereinafter, in each member, the length in the thickness direction of the flat filter membrane 22 will be referred to as width. In order to efficiently bring out the filtration performance of the filtration membrane 22, it is desirable that the inner diameters of the two protrusions (23b, 23c) of the suction side socket 23 be the same as the width of the filtration membrane 22. Then, as shown in FIG. 2, the respective tube peripheral walls of the two protrusions (23b23c) protrude from the socket body 23a in the width direction. That is, the outer diameters of the two protrusions (23b, 23c) are larger than the width of the socket body 23a.

With such a configuration, it becomes difficult to downsize the filtration system (31 in FIG. 5). Specifically, in order to reduce the size of the filtration system, it is desirable to make the pitch in the arrangement direction of the plurality of filtration membrane units (21 in FIG. 6) as small as possible. The aforementioned narrowing of the arrangement pitch is restricted by the respective outer diameters of the two protrusions (23b, 23c) of the suction side socket 23.

The reason why the aforementioned narrowing of the arrangement pitch is restricted by the outer diameter of the protrusions (23b, 23c) is as follows. That is, each of the plurality of hole pairs provided in the first long side plate (43 in FIG. 7) is an insertion hole located on one side in the short direction of the first long side plate (43) among the two insertion holes. are arranged along the longitudinal direction of the first long side plate (43). In addition, in each of the plurality of hole pairs, the insertion hole located on the other side in the lateral direction of the first elongated side plate (43) out of the two insertion holes is also located on the other side in the lateral direction of the first elongated side plate (43). Arrange along the direction. Hereinafter, two insertion holes adjacent to each other along the longitudinal direction will be referred to as "two adjacent insertion holes." As the filtration system (31 in FIG. 5) becomes smaller, the arrangement pitch (the arrangement pitch along the longitudinal direction of the first long side plate 43) of the plurality of filtration membrane units (21 in FIG. 6) becomes smaller. The distance between "two adjacent insertion holes" becomes shorter. If this distance becomes excessively short, the length between the holes of the first long side plate (43) (the portion between "two adjacent insertion holes") becomes excessively small, and the length between the holes of the first long side plate (43) becomes excessively small. The necessary strength cannot be obtained. In the above-mentioned hole portion of the first long side plate (43), the hole length (narrow limit value) that provides the minimum strength is the same even if the material and thickness of the first long side plate (43) are the same. is constant. On the other hand, even if the arrangement pitch of the plurality of filtration membrane units 21 is the same, if the outer diameters of the protrusions (23b, 23c) are different, the above-mentioned inter-hole lengths will be different. As the outer diameter of the protrusion (23b, 23c) becomes larger, the length between the holes becomes smaller (the strength of the portion between the holes becomes lower). Therefore, the narrowing of the arrangement pitch of the insertion holes is restricted by the outer diameter of the protrusions (23b, 23c).

Therefore, in the suction side socket (23) of the filtration membrane unit 21 according to the embodiment, each of the two protrusions (23b, 23c) is arranged in the manner shown in FIG. 3. Specifically, the distance α from the center in the extending direction of the socket body 23a (the position indicated by the dashed line L1) to the first protrusion 23b and the distance β from the center to the second protrusion 23c are set to each other. This is an embodiment in which they are different (α<β). In such a configuration, compared to the case where the length between the holes of the first elongated side plate (43) is narrowed to the narrowing limit value, and the distance α and the distance β are made the same, it is possible to reduce the distance between the plurality of filter membranes. The effect of reducing the arrangement pitch of the units (21) can be achieved.

The reason why the above-mentioned effects can be achieved is as explained below. That is, there are two types of hole pairs provided in the first long side plate 43 shown in FIG. Among the plurality of hole pairs, the first type hole pair 43c is classified as the first type, and the second type hole pair 43f is classified as the second type. The first type hole pairs 43c and the second type hole pairs 43f are arranged alternately along the longitudinal direction (vertical direction in FIG. 7) of the first long side plate 43. The distance between the two insertion holes (43a, 43b) in the first type hole pair 43c and the distance between the two insertion holes (43d, 43e) in the second type hole pair 43f are the same. Of the two insertion holes (43a, 43b) of the first type hole pair 43c, the insertion hole 43a located on one side (upper side in FIG. 7) in the lateral direction of the first elongated side plate 43 is the first elongated hole pair 43c. It is arranged at a predetermined first position along the lateral direction of the first long side plate 43 within the plane of the side plate 43 . This first position is indicated by a dashed line L2 in FIG. Of the two insertion holes (43d, 43e) of the second type hole pair 43f, the insertion hole 43d located on one side (upper side in FIG. 7) in the transverse direction of the first elongated side plate 43 is the first elongated hole pair 43f. It is arranged at a predetermined second position along the lateral direction of the first long side plate 43 within the plane of the side plate 43 . This second position is indicated by a dashed line L3 in FIG. In the lateral direction of the first elongated side plate 43, the above-mentioned first position and second position are different from each other.

Two protrusions (23b, 23c) of the filtration membrane unit (21) that take a predetermined first posture are inserted into the first type hole pair 43c. On the other hand, two protrusions (23b, 23c) of the filtration membrane unit (21) that take a predetermined second attitude are inserted into the second type hole pair 43f. The filtration membrane unit (21) that takes the first attitude and the filtration membrane unit (21) that takes the second attitude are located between the center of the suction side socket (23) in the extending direction and the extension of the shielding side socket (24). It is located at a point-symmetrical position (180° rotated position) with respect to the axis passing through the center of the direction (dotted chain line L4 in FIG. 2).

Hereinafter, in each member, the positional deviation of the first elongated side plate 43 along the short direction will be simply referred to as positional deviation. Among the two insertion holes (43a, 43b) of the first type hole pair 43c, the insertion hole 43a located at the above-mentioned first position (dotted chain line l2) and the two insertion holes (43a, 43b) of the second type hole pair 43f 43d, 43e), the insertion hole 43e located at the second position (dotted chain line L2) is shifted from the insertion hole 43e. One of the two adjacent filtration membrane units (21) inserts the two protrusions (23b, 23c) of the suction side socket (23) into the two insertion holes (43a, 43b) of the first type hole pair 43c. are doing. In the other filtration membrane unit (21), the two protrusions (23b, 23c) of the suction side socket (23) are inserted into the two insertion holes (43d, 43e) of the second type hole pair.

In this configuration, in the longitudinal direction of the first long side plate 43, the other end of the adjacent insertion hole located on one side of the "two adjacent insertion holes" is connected to the adjacent insertion hole located on the other side. It is possible to secure the portion between the holes of the first elongated side plate 43 while locating it on the other side of the hole rather than one end of the hole. More specifically, in FIG. 7, the longitudinal direction of the first long side plate 43 is generally along the left-right direction in FIG. 7 (strictly speaking, the longitudinal direction is slightly inclined from the left-right direction in FIG. 7). ) Therefore, hereinafter, the longitudinal direction of the first long side plate 43 will be described as the left-right direction in FIG. 7. For example, among the plurality of hole pairs provided in the first elongated side plate 43, the insertion hole 43a of the first type hole pair 43c located on the leftmost side in the left-right direction in the figure, and the insertion hole 43a on the right side in the left-right direction in the figure. Let's focus on the insertion holes 43d of the adjacent second type hole pair 43f as "two adjacent insertion holes." The insertion hole 43a of the first seed hole pair 43c is located on the left side in the left-right direction in the figure than the insertion hole 43d of the second seed hole pair 43f. In other words, the insertion hole 43a of the first type hole pair 43c is the adjacent insertion hole located on the other side in the longitudinal direction of the first long side plate 43 among the two adjacent insertion holes, and the second type hole Attention is focused on an example in which the insertion holes 43d of the pair 43f are adjacent insertion holes located on one side in the longitudinal direction. In this example, the left (other side) end of the insertion hole 43d of the second type hole pair 43f is located to the left of the right (one side) end of the insertion hole 43a of the first type hole pair 43c. . While maintaining such a positional relationship, in the first elongated side plate 43, an inter-hole portion between the insertion hole 43a and the insertion hole 43d is secured. As the amount of positional deviation between the insertion hole 43a and the insertion hole 43d becomes larger, the inter-hole length of the above-mentioned inter-hole portion becomes larger. Therefore, even if the diameter of the two protrusions (23b, 23c) of the suction side socket (23) is increased or the arrangement pitch of the plurality of filtration membrane units (21) is narrowed, the above-mentioned position By increasing the amount of deviation, it is possible to make the length between the holes equal to or greater than the narrowing limit value.

Therefore, according to the filtration system 31, the arrangement pitch of the plurality of filtration membrane units 21 can be adjusted without causing positional displacement of the plurality of filtration membrane units 21 (positional displacement along the short direction of the first long side plate 43). The filtration system 31 can be made smaller by narrowing the filtration system 31. In addition, according to the filtration system 31, the filtration performance of the filtration membrane 22 can be improved by increasing the diameter of the two protrusions (23b, 23c) of the suction side socket (23).

The blind cassette 60 shown in FIG. 6 includes a plurality of shielding-side insertion holes (not shown) on the surface facing the plurality of filtration membrane units 21. These shield-side insertion holes are insertion holes into which the protrusion 24b of the shield-side socket 24 of the filtration membrane unit 21 is inserted. By inserting each of the two protrusions 24b of the shielding side socket 24 into the shielding side insertion hole provided on the opposing surface, the other end in the longitudinal direction of the filtration membrane unit 21 is inserted into the blind cassette 60. It is positioned against. In addition, the other end of the filter membrane unit 21 in the longitudinal direction is held in the blind cassette 60.

Although an example has been described in which a plurality of shielding side insertion holes are arranged on the face of the blind cassette 60 facing the plurality of filtration membrane units 21, and two protrusions 24b are provided in the shielding side socket 24 of the filtration membrane unit 21. , the shield-side insertion hole, and the protrusion 24b may be omitted. In this case, for example, by using the following rubber member, it is possible to hold the end of each of the plurality of filtration membrane units 21 on the other side (shielding side) in the longitudinal direction. That is, the rubber member includes a base plate extending along the longitudinal direction of the blind cassette 60, and a plurality of partition plates that protrude from the surface of the base plate and are arranged at a predetermined arrangement pitch along the longitudinal direction of the blind cassette 60. It is. The shield-side socket 24 of the filtration membrane unit 21 may be sandwiched between two adjacent partition plates of this rubber member.

Furthermore, although an example in which the filtration membrane 22 has a flat plate shape has been described, the shape of the filtration membrane 22 is not limited to a flat plate shape, and may be, for example, a corrugated plate shape.

Stress is applied to the filtration membrane unit 21 by the flow of raw water (W ₁ ) existing around the filtration membrane unit 21, bubbles released from the bubble generator 90, and the like. Due to this stress, the filtration membrane unit 21 is subjected to a force (skew force) that tends to tilt the lateral direction of the filtration membrane 22 from the lateral direction of each of the water collection cassette 41 and the blind cassette 60 (vertical direction in FIG. 6). ) is added. Due to this skew force, out of the entire area of the filtration membrane 22, the area near the first protrusion 23b of the suction side socket 23, the area near the second protrusion 23c of the suction side socket, and the two protrusions of the shielding side socket 24 are affected. A large force is applied to the region close to 24b. Hereinafter, the above-mentioned four regions will be collectively referred to as a region near the protrusion.

As shown in FIG. 3, the first protruding body 23b of the suction side socket 23 is located on one side (in the same figure) of the second protruding body 23c in the transverse direction (vertical direction in FIG. 3) of the filtration membrane (22). (hereinafter, this amount of deviation will be referred to as the "first deviation amount"). Furthermore, the first protruding body 23b is disposed at a position shifted toward the center of the socket body 23a from one end (the upper side in FIG. 3) of the socket body 23a in the lateral direction (hereinafter referred to as This amount of deviation is referred to as the "second deviation amount").

Hereinafter, of the two protrusions 24b provided on the shielding socket 24, the one located on one side (upper side in the figure) in the transverse direction (vertical direction in the figure) of the filtration membrane (22) will be referred to as "one side". side protrusion 24b. Furthermore, of the two protrusions 24b, the one located on the other side (lower side in the figure) in the transverse direction is referred to as "the other protrusion 24b." "One side protrusion 24b" is located at a position shifted from one end (upper end in the figure) to the other side (lower side in the figure) in the extending direction of the socket body (24a) (hereinafter referred to as , this amount of deviation is called the "third deviation amount"). In addition, "the protrusion 24b on the other side" is located at a position shifted to one side (upper side in the figure) from the other end (lower end in the figure) in the extending direction of the socket body (24a). Hereinafter, this amount of deviation will be referred to as the "fourth deviation amount."

A comparative example different from the example shown in FIG. 3 will be considered for comparison with the example shown in FIG. 3. In the comparative example, the first protruding body 23b of the suction side socket 23 is located at one end (the upper end in the figure) of the filtration membrane (22) in the transverse direction. Further, the second protruding body 23c of the suction side socket 23 is located at the other end (lower end in the figure) of the filtration membrane (22) in the transverse direction.

In the shielding socket 24 of the comparative example, the "one side protrusion 24b" is located at one end (the upper end in the figure) of the filtration membrane (22) in the transverse direction. Moreover, "the protruding body 24b on the other side" is located at the other end (lower end in the figure) of the filtration membrane (22) in the transverse direction.

That is, in the comparative example, the "first shift amount", "second shift amount", "third shift amount", and "fourth shift amount" are all zero. In the comparative example with such a configuration, the distance between the first protrusion 24b and the second protrusion 24c of the suction side socket 23 is longer than the same distance in the filtration membrane unit 21 according to the embodiment. In addition, in the comparative example, the distance between the "one side protrusion 24b" and the "other side protrusion 24b" of the shielding side socket 24 is longer than the same distance in the filtration membrane unit 21 according to the embodiment. . Therefore, in the comparative example, due to the lever principle, the force applied to the region of the filtration membrane 22 near the protrusion is larger than that of the filtration membrane unit 21 according to the embodiment, so that the filtration membrane 22 is likely to be damaged. Become. In other words, in the filtration membrane unit 21 according to the embodiment, by not arranging each protrusion at the end of the socket in the lateral direction of the filtration membrane 22, damage to the filtration membrane 22 due to skew force can be suppressed. can.

In the filtration membrane unit 21 according to the embodiment, in order to efficiently suppress damage to the filtration membrane 22, the "first deviation amount", "second deviation amount", "third deviation amount", and "fourth deviation amount" are ” should be as large as possible. However, if the "first deviation amount" and "second deviation amount" are excessively increased in the suction side socket 23, the amount of water collected from the first protrusion 23b and the amount of water collected from the second protrusion 23c will not be equal. It will be difficult to achieve this goal. In order to achieve the above-mentioned uniformity, each of the "first deviation amount" and the "second deviation amount" is set to 1/10 or less of the length in the extending direction of the socket body 23a of the suction side socket 23. This is desirable. More desirably, a range of 1/4 to 1/3 of the length of the socket body 23a of the suction side socket 23 in the extending direction is preferably adopted. The same applies to the "third shift amount" and "fourth shift amount" in the shielding side socket 24.

In the lateral direction of the filtration membrane (22), the first protruding body 23b is disposed at a position shifted to one side (upper side in FIG. 3) from the center of the socket body 23a, and the second protruding body 23c is disposed at a position shifted from the center of the socket body 23a. It is arranged at a position shifted to the other side (lower side in FIG. 3). In such a configuration, both the first protruding body 23b and the second protruding body 23c are disposed at positions shifted from the center to either one side or the other side, thereby improving the filtration membrane unit (21). Shaking on the side where the protrusion is not arranged is prevented. Therefore, according to the filtration membrane unit (21) according to the embodiment, it is possible to prevent the filtration membrane (22) from being damaged due to the aforementioned vibration.

Although the filtration system (31) adopts the so-called single-pull method in which only one side of the longitudinal sides of the filtration membrane 22 is used as the suction side, the filtration system (31) adopts the so-called double-pull method in which each of both sides is used as the suction side. It's okay. In this case, suction side sockets 23 having a similar configuration may be provided as the respective sockets on both sides.

FIG. 8 is a perspective view showing the filtration treatment equipment 20 according to the embodiment. The filtration treatment facility 20 includes three filtration systems 31. The three filtration systems 31 are lined up along the short direction of the first long side plate (43). In the figure, since the short side direction is along the vertical direction, the structure of the filtration treatment equipment 20 is a three-stage structure in which three filtration systems 31 are stacked in the vertical direction.

FIG. 9 shows the water collection cassette 41 of the filtration system (31) disposed on one side (upper side in the figure) of the first long side plate (43) in the width direction and the other side (upper side in the figure) of the first elongated side plate (43). It is a perspective view which shows the water collection cassette 41 of the filtration system (31) arrange|positioned at the lower side in a figure, and the connecting pipe 70. The connecting pipe 70 plays a role of connecting the two water collection cassettes 41. In each of the top plates 42 of the two water collection cassettes 41 shown in FIG. 9, three top plate openings 42a are arranged in a manner that they are lined up at predetermined intervals along the longitudinal direction of the top plate 42. The top plate opening 42a faces one side (upper side in the figure) of the first long side plate 43 in the lateral direction (vertical direction in the figure).

Three cylindrical first connection sockets 50 are arranged inside the water collection cassette 41. These first connection sockets 50 are fixed to the back surface of the top plate 42 and communicate with the top plate opening 42a.

Three bottom plate openings 45a are arranged in the bottom plate 45 of each of the three water collection cassettes 41 so as to be lined up at predetermined intervals along the longitudinal direction of the bottom plate 45. The bottom plate opening 45a faces the other side (lower side in the figure) of the first long side plate 43 in the lateral direction.

One of the three top plate openings 42a and one of the three bottom plate openings 45a face each other along the short direction of the first long side plate 43. Further, another one of the three top plate openings 42a and another one of the three bottom plate openings 45a face each other along the lateral direction. Furthermore, the last one of the three top plate openings 42a and the last one of the three bottom plate openings 45a face each other along the lateral direction.

Three cylindrical second connection sockets 51 are provided inside the water collection cassette 41. These second connection sockets 51 are fixed to the back surface of the bottom plate 45 and communicate with the bottom plate opening 45a.

The water collection cassette 41 arranged on the lower side of the figure and the water collection cassette 41 arranged on the upper side of the figure are connected by three connecting pipes 70. The connecting pipe 70 is arranged in such a manner that the pipe length direction is aligned with the lateral direction (the vertical direction in the figure) of the first elongated side plate 43. A ring-shaped recess (not shown) extending over the entire circumference of the pipe circumferential surface is arranged at one end and the other end of the connecting pipe 70 in the transverse direction, respectively. An O-ring 71 is fitted into the ring-shaped recess.

The one end (upper side in the figure) of the connecting pipe 70 in the lateral direction is inserted into the second connection socket 51 of the water collection cassette 41 on the upper side in the figure. Further, the other (lower side in the figure) end of the connecting pipe 70 in the lateral direction is inserted into the first connecting socket 50 of the water collection cassette 41 on the upper side of the figure. The accommodation space for the water collection cassette 41 on the upper side of the figure and the accommodation space for the water collection cassette 41 on the lower side of the figure communicate with each other through three connecting pipes 70.

Note that among the three water collection cassettes 41 stacked in three tiers, in the bottom water collection cassette 41, the connection pipes 70 are not inserted into each of the three second connection sockets 51, but are inserted into each of the three second connection sockets 51. A sealing plug (not shown) is inserted into the second connection socket 51. This prevents the suction force generated in the accommodation space of the lowermost water collection cassette 41 from leaking to the outside through the second connection socket 51.

Furthermore, among the three water collection cassettes 41 that are stacked in three tiers, in the top water collection cassette 41, the connection pipes 70 are not inserted into the three first connection sockets 50, but are branched for water collection. A tube is inserted. These water collection branch pipes are connected to one treated water transfer pipe (8 in FIG. 1).

The storage space of the water collection cassette 41 on the lower side of the figure contains treated water that has passed through the filter membranes of a plurality of filter membrane units (not shown) held by the first long side plate 43 of the water collection cassette 41. will flow in. In addition, in the storage space of the water collection cassette 41 on the upper side of the figure, treated water that has passed through the filtration membranes of a plurality of filtration membrane units (not shown) held by the first long side plate 43 of this water collection cassette 41 is stored. Water flows in. The treated water present in the accommodation space of the water collection cassette 41 on the lower side of the figure is sucked into the accommodation space of the upper water collection cassette 41 through the connection pipe 70 by the suction force generated inside the connection pipe 70. be done.

That is, in each of the three filtration systems 31 shown in FIG. 8, treated water that has passed through each of the plurality of filtration membranes 22 is collected in the water collection cassette 41. In each of the water collection cassettes 41 of the three filtration systems 31, the treated water in the storage space of the water collection cassette 41 located lower is transferred to the storage space of the water collection cassette 41 located higher. is sucked into. As a result, the treated water collected in the storage spaces of the three water collection cassettes 41 is finally collected in the storage space of the uppermost water collection cassette 41, and is then transferred to the treated water tank ( It is transferred to 3) in FIG.

In the connecting pipe 70 shown in FIG. 9, the pipe length direction is along the lateral direction of the first long side plate 43, as described above. The O-ring 71 fitted into the end of the connecting pipe 70 on one side (the upper side in the figure) in the short direction prevents the end inserted into the second connecting socket 51 from coming out of the second connecting socket 51. This improves the sealing performance between the end portion and the second connection socket 51. In order to more reliably avoid the above-mentioned slippage or to further improve the above-mentioned sealing performance, a plurality of O-rings 71 arranged in the lateral direction may be fitted into the end portion.

The O-ring 71 fitted into the other (lower side in the figure) end of the connecting pipe 70 in the short direction allows the O-ring 71 to be inserted into the first connecting socket 50 at the end inserted into the first connecting socket 50. This prevents the end portion from coming off and improves the sealing performance between the end portion and the first connection socket 50. In order to more reliably avoid the above-mentioned slippage or to further improve the above-mentioned sealing performance, a plurality of O-rings 71 arranged in the lateral direction may be fitted into the end portion.

The number of the top plate opening 42a, the bottom plate opening 45a, the first connection socket 50, the second connection socket 51, and the connection pipe 70 is not limited to three. It is sufficient if there is one or more.

Although the filtration treatment equipment (20) in which a plurality of filtration systems (31) are stacked in a multi-stage system has been described, a multi-layer system in which a plurality of filtration systems (31) are connected horizontally and a multi-stage system may also be used together. good.

The filtrate sent from another filtration system is sent into the accommodation space of the water collection cassette 41 along the substantially vertical direction. On the other hand, filtrate from a plurality of filtration membrane units communicating with the accommodation space is sent along a substantially horizontal direction. In the storage space, such a vertical flow and a horizontal flow may combine, or the inflowing filtrate may not move smoothly toward the downstream channel and may spread. Easy to generate turbulence. When flow path resistance increases due to turbulence, extra power is required, resulting in a decrease in energy efficiency.

Therefore, the filtration treatment equipment (20) according to the embodiment is provided with a guide pipe in each accommodation space. FIG. 10 is a perspective view showing the guide tube 150. The guide tube 150 is made of a cylinder as a tubular member with a plurality of through holes 152 arranged in the peripheral wall. The guide pipe 150 communicates with a first connecting socket 50 as an upper communication channel and a second connecting socket 51 as a lower communicating channel, and is connected between the first connecting socket 50 and the second connecting socket 51. Guide the flow of water. In addition, the guide pipe 150 takes in the treated water in the accommodation space of the water collection cassette (41) into its own pipe through the plurality of through holes 152.

FIG. 11 is a perspective view for explaining the flow of treated water in the storage space in the upper stage transfer method in which treated water is transported toward the upper stage. In the upper stage transfer method, treated water sent from the lower stage storage space flows into the guide pipe 150 through the second connection socket 51. The inflowing treated water is guided toward the first connection socket 50 by a flow path formed by the guide pipe 150 . Therefore, much of the treated water smoothly flows from the second connection socket 51 to the first connection socket 50. This flow acts as a suction force toward the first connection socket 50 on the treated water present around the guide pipe 150 . As a result, the treated water existing around the guide pipe 150 is sucked diagonally upward into the through hole 152 as shown.

FIG. 12 is a perspective view for explaining the flow of treated water within the storage space in a lower stage transfer method in which treated water is transported toward the lower stage. In the lower stage transfer method, treated water sent from the upper stage storage space flows into the guide pipe 150 through the first connection socket 50. The treated water that has flowed in is guided toward the second connection socket 51 by the flow path formed by the guide pipe 150 . Therefore, much of the treated water flows smoothly from the first connection socket 50 to the second connection socket 51. This flow acts on the treated water existing around the guide pipe 150 as a suction force toward the second connection socket 51 . As a result, the treated water existing around the guide pipe 150 is sucked diagonally downward into the through hole 152 as shown in the figure.

As described above, the guide pipe 150 handles not only the treated water flowing into the guide pipe 150 via the first connection socket 50 or the second connection socket 51, but also the treated water existing around the guide pipe 150. It also guides you to move in the desired direction. In this configuration, by guiding the flow of treated water in the storage space in a preferable direction by the guide pipe 150, generation of turbulent flow in the storage space is suppressed, and a decrease in energy efficiency due to turbulence is suppressed. be able to.

Next, an example of the filtration treatment equipment (20) will be described. Note that unless otherwise specified below, the configuration of the filtration treatment equipment (20) according to the example is the same as that in the embodiment.

It is assumed that the filtration system (31) of the filtration treatment equipment (20) according to the example is in an upside-down position. Even if the posture of the filtration system (31) is flipped upside down in this way, the two-dimensional layout of each insertion hole on the plane of the first long side plate (43) of the water collection cassette (41) remains the same as before upside down. Each insertion hole is arranged so that In addition, in the water collection cassette (41), the plate material that functioned as the top plate (42) before being turned upside down functions as the bottom plate (45) after being turned upside down, and functions as the bottom plate (45) before being turned upside down. The plate material that was used as a top plate functions as a top plate (42) after being turned upside down. In the region from one longitudinal end to the other end of the water collection cassette (41), the relative positions of the three top plate openings (42a) of the top plate (42) before being turned upside down and the top plate (42) after being turned upside down are ) are the same relative to the three top plate openings (42a). Therefore, in the region from one end to the other end in the longitudinal direction of the water collection cassette 41, the relative positions of the three bottom plate openings (45a) of the bottom plate (45) before being turned upside down and the position of the bottom plate (45) after being turned upside down are The relative positions with the three bottom plate openings (45a) are the same. Therefore, in the filtration treatment equipment (20) according to the embodiment, the filtration system (31) can be handled without worrying about the vertical posture of the filtration system (31).

FIG. 13 is a cross-sectional view showing a longitudinal cross-section of two water collection cassettes 41 stacked one above the other in the filtration treatment equipment (20) according to the embodiment, along with a cross-section of the connecting pipe 70. FIG. 14 is a cross-sectional view showing a cross section of the connecting pipe 70 on a larger scale than in FIG. 10. As shown in FIG.

As shown in FIG. 14, each of the three first connection sockets 50 fixed to the top plate 42 of the water collection cassette 41 is provided with a female screw portion 50a on the inner peripheral surface. The female threaded portion 50a is provided in an upwardly biased region of the entire length of the first connection socket 50 made of a tube material. Further, each of the three second connection sockets 51 fixed to the bottom plate 45 of the water collection cassette 41 includes a female screw portion 51a on the inner peripheral surface. The female threaded portion 51a is provided in a region biased toward the lower side of the entire length of the second connection socket 51 made of a tube material.

When the posture of the water collection cassette 41 is reversed vertically, the plate material that was functioning as the top plate 42 before being reversed vertically functions as the bottom plate 45, and the pipe material that was functioning as the first connection socket 50 before being reversed vertically, It functions as a second connection socket 51. As shown in FIG. 14, the connecting pipe 70 includes a male threaded portion 70a on its outer peripheral surface. The male threaded portion 70a is provided in a region biased to one side of the entire length of the connecting pipe 70 in the pipe length direction. The connecting pipe 70 is used in such a manner that, of both ends of the connecting pipe 70 in the pipe length direction, the end provided with the male threaded portion 70a is located below the other end.

In FIG. 13, each of the three connecting pipes 70 has a male threaded portion 70a attached to the female threaded portion 50a of the first connecting socket 50 of the lower one of the two water collecting cassettes 41. It is inserted into this first connection socket 50 while doing so. The above-mentioned screw can prevent the connecting pipe 70 from coming off from the first connecting socket 50. Further, when separating the upper water collection cassette 41 and the lower water collection cassette 41 for maintenance and inspection work, each of the three connecting pipes 70 is held in the lower water collection cassette 41. Since the condition can be maintained reliably, the workability of maintenance and inspection can be improved.

In the filtration treatment equipment (20), among the three filtration systems (31) stacked in three tiers, the second connection socket 51 in the water collection cassette 41 of the lowest filtration system (31) is equipped with a connection pipe. 70 is not inserted. Instead, a sealing plug (not shown) having a male thread on its outer peripheral surface is inserted into the second connection socket 51. At this time, the sealing plug is inserted into the second connection socket 51 while threading its male threaded portion into the female threaded portion 51a of the second connection socket 51. The sealing plug inserted into the second connection socket 51 in this manner is prevented from coming off from the second connection socket 51 by the aforementioned screw.

Of the three filtration systems (31) in the filtration treatment facility (20), the connection pipe 70 is not inserted into the first connection socket 50 in the water collection cassette 41 of the uppermost filtration system (31). Instead, the above-mentioned water collection branch pipe is inserted into the first connection socket 50. A male threaded portion is provided on the outer peripheral surface of this water collection branch pipe. The water collection branch pipe is inserted into the first connection socket 50 while screwing its own male thread into the female thread of the first connection socket 50. The water collection branch pipe inserted into the first connection socket 50 in this manner is prevented from coming off from the first connection socket 50 by the above-mentioned screw.

The present invention is not limited to the above-described embodiments and examples, and configurations different from the embodiments and examples may be adopted within the scope where the configuration of the present invention is applicable. The present invention provides specific effects for each aspect described below.

[First aspect]
The first aspect includes a plurality of filtration membrane units (e.g., filtration membrane unit 21) that cause the filtrate taken into the filtration membrane (e.g., filtration membrane 22) to flow along the longitudinal direction of the filtration membrane, and a plurality of the filtration membrane units. an accommodation space that accommodates the filtrate discharged from each of the accommodation spaces; an upper communication channel (for example, the first connection socket 50) that communicates the upper part of the accommodation space with an external space above the accommodation space; A filtration system (for example, a filtration system 31) comprising a lower communication channel (for example, a second connection socket 51) that communicates a lower part with an external space below the accommodation space, the filtration system having a plurality of through holes (for example, a through hole) in a peripheral wall. It is made of a tubular member (for example, a cylinder) in which holes 152) are arranged, and communicates with the upper communication channel and the lower communication channel to allow liquid to flow between the upper communication channel and the lower communication channel. The device is characterized by comprising a guide tube (for example, guide tube 150) that guides the filtrate in the accommodation space into the interior of the container through the plurality of through holes.

According to this configuration, by guiding the flow of the filtrate in the storage space in a preferable direction by the guide pipe, generation of turbulent flow in the storage space can be suppressed, and a decrease in energy efficiency caused by the turbulence can be suppressed. Can be done.

[Second aspect]
A second aspect is a filtration system having the configuration of the first aspect, wherein a pair of the upper communication channel and the lower communication channel that face each other along the vertical direction are arranged along the longitudinal direction of the accommodation space. The present invention is characterized in that a plurality of guide pipes are arranged and individually communicate the upper communication channel and the lower communication channel in each pair.

According to this configuration, by guiding the behavior of the filtrate in a preferable direction at mutually different positions in the longitudinal direction of the accommodation space, it is possible to better suppress the occurrence of turbulent flow.

[Third aspect]
A third aspect is a filtration treatment facility (for example, the filtration treatment facility 20) that includes a plurality of filtration systems arranged in multiple stages, and each of the plurality of filtration systems is the filtration system of the first aspect or the second aspect. It is characterized by this.
can.

[Fourth aspect]
A fourth aspect is a filtration treatment facility having the configuration of the third aspect, in which one of the upper communication passages and the other lower communication passage in the two filtration systems that are vertically adjacent to each other, Each of the tubes has a female thread on its inner circumferential surface, and is connected to each other by a connecting tube inserted inside each tube, and one longitudinal end of the connecting tube has an O-ring made of an elastic material on its outer circumferential surface. , the other end of the connecting pipe in the length direction is provided with an O-ring made of an elastic material and a male threaded part disposed closer to the one end than the O-ring on the outer peripheral surface thereof. .

According to such a configuration, the screws between the female threaded portion and the male threaded portion can prevent the connecting pipe from coming off from the upper communication channel or the lower communication channel. In particular, if the male threaded part of the connecting pipe and the female threaded part of the lower communication channel of the lower filtration system are screwed together, the connecting pipe can be lowered when separating the two filtration systems for maintenance and inspection work. Since it can be left naturally in the filtration system on the side, it is possible to improve the workability of maintenance and inspection.

20... Filtration processing equipment, 21... Filtration membrane unit, 22... Filtration membrane, 23... Suction side socket (socket), 23a... Socket body, 23b... First protruding body, 23b-1...Hollow, 23b-2...First outlet, 23c...Second protrusion, 23c-1...Hollow, 23c-2...Second outlet, 23d...Concave part , 23e...flow path, 31...filtration system

Claims

A plurality of filtration membrane units through which the filtrate taken into the filtration membrane flows along the longitudinal direction of the filtration membrane, a housing space for accommodating the filtrate discharged from each of the plurality of filtration membrane units, and a housing space in the housing space. A filtration system comprising: an upper communication channel that communicates an upper part with an external space above the accommodation space; and a lower communication channel that communicates a lower part of the accommodation space with an external space below the accommodation space, ,
It is made of a tubular member with a through hole arranged in a peripheral wall, and communicates with the upper communication channel and the lower communication channel to guide the flow of liquid between the upper communication channel and the lower communication channel. A filtration system, comprising: a guide tube that takes the filtrate in the storage space into the filtration system through the through hole.
The filtration system according to claim 1,
A plurality of pairs of the upper communication channel and the lower communication channel facing each other along the vertical direction are arranged along the longitudinal direction of the accommodation space,
A filtration system characterized in that a plurality of guide pipes are arranged that individually communicate the upper communication channel and the lower communication channel in each pair.
A filtration treatment facility comprising a plurality of filtration systems arranged in multiple stages,
A filtration treatment facility, wherein each of the plurality of filtration systems is the filtration system according to claim 1 or 2.
The filtration treatment equipment according to claim 3,
In the two filtration systems that are adjacent to each other in the vertical direction, one of the upper communication channels and the other lower communication channel are provided with female threads on their respective inner circumferential surfaces, and are inserted into the respective insides. connected to each other by a connecting pipe,
One longitudinal end of the connecting pipe is provided with an O-ring made of an elastic material on the outer peripheral surface,
A filtration treatment facility characterized in that the other end in the length direction of the connecting pipe is provided with an O-ring made of an elastic material and a male screw portion disposed closer to the one end than the O-ring on the outer peripheral surface.