JP6458304B2 - Membrane module, membrane module manufacturing method, and water treatment system - Google Patents

Description

  The present invention relates to a membrane module for treating organic wastewater such as human waste, a method for producing the membrane module, and a water treatment system.

When organic wastewater such as human waste is treated, it is the mainstream to use membrane separation such as MF (microfiltration) and UF (ultrafiltration) for solid-liquid separation.
As the membrane separation device, a plurality of membrane modules including a cylindrical casing and a plurality of tubular filtration membranes (hollow fiber membranes) accommodated in the casing are used, and raw water is circulated inside the tubular filtration membrane. An apparatus using a filtration method is known (for example, see Patent Document 1). The permeated water that has permeated through the tubular filtration membrane is sucked by a suction pump and stored in, for example, a storage tank and used as appropriate.

JP 2013-052338 A

  By the way, in the conventional membrane separation apparatus, a plurality of membrane modules are generally placed vertically, that is, arranged so that the axis of the casing is along the vertical direction and are close to each other. Such an arrangement method is advantageous in that the installation area is reduced and each membrane module can be directly installed on one floor surface.

  However, when a plurality of membrane modules are placed vertically, for example, when replacing or repairing a membrane module installed on the back side, the membrane module to be exchanged is lifted or the membrane module on the front side is temporarily It was necessary to remove the membrane module to be replaced. That is, in the membrane separation apparatus in which a plurality of membrane modules are placed vertically, there is a problem that the maintainability is poor.

  In order to improve the maintainability of the membrane separation apparatus, it is conceivable to place a plurality of membrane modules horizontally. However, when the membrane module is placed horizontally, there is a problem that a plurality of tubular filtration membranes extending in the horizontal direction along the axis of the casing bend.

  An object of this invention is to provide the membrane module which can suppress the bending of a tubular filtration membrane, the manufacturing method of a membrane module, and a water treatment system, when a membrane module is set horizontally.

According to the first aspect of the present invention, the membrane module includes a cylindrical casing having an axial line extending in a horizontal direction, a first partition wall provided at one end in the extending direction of the casing, and an extension of the casing. A second partition provided at the other end in the existing direction; a hydrophilic portion extending in the horizontal direction inside the casing, having one end connected to the first partition and the other end connected to the second partition A plurality of tubular filtration membranes having a single-layer structure in which a functional monomer is copolymerized, and a reinforcing member that reinforces the tubular filtration membrane in a range between the first partition wall and the second partition wall , The reinforcing member has a cylindrical shape, is disposed on the outer peripheral side of the tubular filtration membrane, and is formed so that a gap formed between the outer peripheral surface of the tubular filtration membrane is constant, The cylindrical main body is disposed on the inner peripheral surface of the cylindrical main body so as to be spaced apart from each other. Of axially extending, having a plurality of support portions for supporting the outer peripheral surface of said tubular filtration membranes, a plurality of through-holes formed in the cylindrical body portion.

According to such a configuration, the plurality of tubular filtration membranes are reinforced by the reinforcing member, thereby preventing the tubular filtration membranes from being bent even when the tubular filtration membranes are arranged to extend in the horizontal direction. can do.
In addition, by arranging the membrane modules such that the casing extends in the horizontal direction, the membrane modules can be easily replaced even when a plurality of membrane modules are arranged. Thereby, the maintenance of the membrane separator comprising a plurality of membrane modules can be facilitated.

  According to such a configuration, the tubular filtration membrane can be supported so as not to bend without hindering the flow of permeated water permeated from the tubular filtration membrane.

According to a second aspect of the present invention, a method of manufacturing a membrane module, a method of manufacturing the above Kimaku module, a crude fiber content measurement step of measuring the proportion of crude fiber content in the treated water, A membrane inner diameter selecting step for selecting an inner diameter of the tubular filtration membrane based on the ratio of the amount of the coarse fibers, and a manufacturing member for the membrane module including the tubular filtration membrane having the inner diameter selected in the membrane inner diameter selection step are prepared. A manufacturing member preparation step, and an assembly step of assembling the manufacturing member.

  According to such a structure, it can suppress that a tubular filtration membrane is obstruct | occluded by a coarse fiber part by selecting the internal diameter of a tubular filtration membrane according to the amount of coarse fibers of to-be-processed water.

According to the third aspect of the present invention, the water treatment system includes a biological treatment water tank that treats organic matter contained in the treated water, and a raw water tank that accommodates the treated water discharged from the biological treatment water tank. , has an upper Kimaku module, a membrane separation apparatus for separating water to be treated and permeate and concentrate water supplied from the raw water tank, a return line for returning the concentrated water to the biological treatment water tank, the And the concentrated water is not returned to the raw water tank.

  According to such a configuration, since the membrane filtration membrane has hydrophilicity, the membrane surface flow rate can be lowered, so that the circulation flow rate of the water to be treated can be reduced. Thereby, the distribution tank which distributes concentrated water to a raw | natural water tank and a biological treatment water tank, and the piping which returns concentrated water to a raw | natural water tank become unnecessary. In addition, the diameter of the pipe can be reduced by reducing the flow rate. In addition, by reducing the flow rate, it is possible to reduce equipment such as a flow meter.

According to the present invention, since the plurality of tubular filtration membranes are reinforced by the reinforcing member, even when the tubular filtration membranes are arranged to extend in the horizontal direction, the tubular filtration membranes bend and come off the partition walls. Further, it is possible to prevent a reduction in processing capacity by forming a gap between the partition wall and the tubular filtration membrane.
In addition, by arranging the membrane modules such that the casing extends in the horizontal direction, the membrane modules can be easily replaced even when a plurality of membrane modules are arranged. Thereby, the maintenance of the membrane separator comprising a plurality of membrane modules can be facilitated.

It is a schematic block diagram of the water treatment system of 1st embodiment of this invention. It is a schematic perspective view of the membrane separator of 1st embodiment of this invention. It is a schematic sectional drawing of the membrane module of 1st embodiment of this invention. It is a perspective view of the reinforcing member of a first embodiment of the present invention. It is the side view which looked at the reinforcement member of a first embodiment of the present invention from the axial direction of the reinforcement member. It is a schematic sectional drawing of the membrane module of the modification of 1st embodiment of this invention. It is a flowchart explaining the manufacturing method of the membrane module of 1st embodiment of this invention. It is a perspective view of the reinforcement member of 2nd embodiment of this invention. It is a perspective view of the reinforcement member of the 1st modification of 2nd embodiment of this invention. It is a perspective view of the reinforcement member of the 2nd modification of 2nd embodiment of this invention. FIG. 10 is a side view of the reinforcing member of the second modified example of the second embodiment of the present invention, as viewed from the arrow X in FIG. 9. It is a perspective view of the reinforcement member of 3rd embodiment of this invention. It is a flowchart explaining the design method of the water treatment system of 4th embodiment of this invention. It is a schematic block diagram of the water treatment system of 4th embodiment of this invention. It is a schematic block diagram of the water treatment system of 4th embodiment of this invention.

(First embodiment)
Hereinafter, the water treatment system 10 having the membrane module 1 of the first embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the water treatment system 10 of the present embodiment includes a biological treatment water tank 11 for treating organic substances contained in the water to be treated W1 (organic wastewater including human waste and septic tank sludge), and a biological treatment water tank 11. The raw water tank 12 in which the treated water W2 discharged is accommodated, and the membrane separation device 13 that separates the treated water W3 (raw water) supplied from the raw water tank 12 into the permeated water PW and the concentrated water W4. ing.

  The biological treatment water tank 11 is a device that decomposes and removes BOD, nitrogen compounds, etc. in the liquid by the action of nitrifying bacteria and denitrifying bacteria, for example. To-be-treated water tank 11 is supplied with treated water W <b> 1 through first pipe 15. The biological treatment water tank 11 and the raw water tank 12 are connected by a second pipe 16.

The membrane separation device 13 includes a plurality of membrane modules 1. The plurality of membrane modules 1 are arranged in parallel. As shown in FIG. 2, the plurality of membrane modules 1 are disposed sideways in the housing 14 of the membrane separation device 13. That is, the axis A (see FIG. 3) of the cylindrical casing 2 of the membrane module 1 extends in the horizontal direction.
As shown in FIG. 3, the membrane module 1 includes a casing 2 and a plurality of tubular filtration membranes 3 arranged inside the casing 2. The membrane separation device 13 is a device that takes out the permeated water PW from the water to be treated W3 by using a method of filtering the water to be treated W3 while circulating it inside the tubular filtration membrane 3.

The raw water tank 12 and the membrane separation device 13 are connected via a raw water supply pipe 17. A circulation pump 21 is provided in the raw water supply pipe 17. The treated water W2 stored in the raw water tank 12 is supplied to the membrane separation device 13 while being pressurized by the circulation pump 21.
The permeated water PW separated from the membrane separation device 13 is introduced into the permeated water pipe 18. The permeated water pipe 18 is connected to the storage tank 20. That is, the permeate discharge port 9 (see FIG. 3) of the membrane module 1 is connected to the permeate pipe 18. A suction pump 22 is provided in the permeate water pipe 18.

The concentrated water W4 separated from the permeated water PW and discharged from the membrane separation device 13 is returned to the biological treatment water tank 11 through the return pipe 19 (return line), except for the excess sludge. That is, the concentrated water discharge port 8 (see FIG. 3) of the membrane module 1 is connected to the return pipe 19, and the concentrated water W4 does not have to be returned to the raw water tank 12.
The treated water W2 discharged from the biological treatment water tank 11 returns to the biological treatment water tank 11 via the raw water tank 12 and the membrane separator 13. That is, the water to be treated circulates in the piping of the water treatment system 10.

  As described above, the plurality of membrane modules 1 are arranged in parallel. Specifically, the raw water supply pipe 17, the permeate water pipe 18, and the return pipe 19 are connected to each membrane module 1.

As shown in FIG. 3, the membrane module 1 includes a cylindrical casing 2, a plurality of tubular filtration membranes 3, and a reinforcing member 34 that reinforces the tubular filtration membrane 3.
The casing 2 includes a cylindrical casing body 4, a first side wall 5 that closes one end of the casing body 4, a second side wall 6 that closes the other end of the casing body 4, and a cover formed on the casing body 4. A treated water introduction port 7, a concentrated water discharge port 8 formed in the casing body 4, and a permeate discharge port 9 formed in the casing body 4 are provided.

  The membrane module 1 includes a first partition wall 30 and a second partition wall 31 that divide the inside of the casing 2 into three spaces. A plurality of insertion holes 32 are formed in the first partition wall 30 and the second partition wall 31. The insertion hole 32 is a hole that penetrates the first partition wall 30 and the second partition wall 31 in the plate thickness direction. The inner diameter of the insertion hole 32 is slightly larger than the outer diameter of the tubular filtration membrane 3.

The first partition 30 is a plate-shaped member, and is fixed to one end side (the first side wall 5 side) inside the casing 2. A space surrounded by the casing body 4, the first partition wall 30, and the first side wall 5 is a first header space S1.
The second partition wall 31 is a plate-shaped member, and is fixed to the other end side (the second side wall 6 side) inside the casing 2. A space surrounded by the casing body 4, the second partition wall 31, and the second side wall 6 is a second header space S2.
A space surrounded by the casing body 4, the first partition wall 30, and the second partition wall 31 is a permeated water space S3. The permeated water PW taken out from the plurality of tubular filtration membranes 3 is discharged into the permeated water space S3 and then introduced into the permeated water pipe 18 (see FIG. 1) through the permeated water discharge port 9.

The treated water introduction port 7 is an opening that allows communication between the outside of the casing 2 and the first header space S1. The treated water inlet 7 is formed in the casing body 4. The treated water introduction port 7 is provided between the first partition wall 30 and the first side wall 5 in the axis A direction of the casing 2.
The concentrated water discharge port 8 is an opening that allows communication between the outside of the casing 2 and the second header space S2. The concentrated water discharge port 8 is formed in the casing body 4. The concentrated water discharge port 8 is provided between the second partition wall 31 and the second side wall 6 in the axis A direction of the casing 2.
The permeated water discharge port 9 is an opening that allows communication between the outside of the casing 2 and the permeated water space S3. The permeated water discharge port 9 is formed in the casing body 4. The permeate discharge port 9 is provided between the first partition wall 30 and the second partition wall 31 in the axis A direction of the casing 2.

One end of each tubular filtration membrane 3 is fixed to the inner peripheral surface of the insertion hole 32 after being inserted into the insertion hole 32 of the first partition wall 30. A space between the inner peripheral surface of the insertion hole 32 and the outer peripheral surface of the tubular filtration membrane 3 is sealed with a sealing material (not shown). As the sealing material, a material that has an initial viscosity and hardens with time, such as an epoxy resin or a urethane resin, is preferable.
The other end of each tubular filtration membrane 3 is fixed to the insertion hole 32 of the second partition wall 31 in the same manner as one end of the tubular filtration membrane 3.

The tubular filtration membrane 3 has a cylindrical shape, and is formed of a polymer filtration membrane having a single layer structure in which a hydrophilic monomer is copolymerized on a single main constituent material.
That is, the tubular filtration membrane 3 is formed of a single material as a main material. That the main material is formed of one kind of material means that one kind of resin occupies 50% by mass or more in the material (for example, resin) forming the tubular filtration membrane 3.
The fact that the main material is formed of one kind of material means that the nature of the one kind of material dominates the nature of the constituent material. Specifically, it means a material in which one kind of resin has 50 mass% to 99 mass%.

  The main materials constituting the tubular filtration membrane 3 include polyolefin chlorides such as vinyl chloride resin, polysulfone (PS), polyvinylidene fluoride (PVDF), polyethylene (PE), polyacrylonitrile (PAN), and polyether. Polymer materials such as sulfone, polyvinyl alcohol (PVA), and polyimide (PI) can be used.

  As a main material constituting the tubular filtration membrane 3, a vinyl chloride resin is particularly preferable. Examples of vinyl chloride resins include vinyl chloride homopolymer (vinyl chloride homopolymer), a copolymer of a monomer having an unsaturated bond copolymerizable with vinyl chloride monomer and vinyl chloride monomer, and vinyl chloride monomer in the polymer. Examples thereof include graft copolymers obtained by graft copolymerization, and (co) polymers composed of chlorinated vinyl chloride monomer units.

Examples of hydrophilic monomers include:
(1) A cationic group-containing vinyl monomer such as an amino group, an ammonium group, a pyridyl group, an imino group or a betaine structure and / or a salt thereof,
(2) Hydrophilic nonionic group-containing vinyl monomers such as hydroxyl groups, amide groups, ester structures, ether structures,
(3) Anionic group-containing vinyl monomer such as carboxyl group, sulfonic acid group, phosphoric acid group and / or salt thereof,
(4) Other monomers may be mentioned.

  The membrane module 1 of the present embodiment includes a reinforcing member 34 that reinforces each tubular filtration membrane 3. The reinforcing member 34 is a cylindrical member that covers each tubular filtration membrane 3 from the outer peripheral side. The tubular filtration membrane 3 is inserted through the inner peripheral side of the reinforcing member 34. The reinforcing member 34 is formed so that the inner peripheral surface of the reinforcing member 34 and the outer peripheral surface of the tubular filtration membrane 3 are in contact with each other over substantially the entire periphery.

As shown in FIG. 4, the reinforcing member 34 includes a cylindrical main body portion 35 disposed on the outer peripheral side of the tubular filtration membrane 3, and a plurality of support portions 36 provided on the inner peripheral surface 35 a of the cylindrical main body portion 35. And a plurality of through holes 37 formed in the cylindrical main body 35.
The cylindrical main body 35 has a cylindrical shape. As shown in FIG. 5, the inner diameter of the cylindrical main body 35 (the diameter of the inner peripheral surface 35 a) is larger than the outer diameter of the tubular filtration membrane 3. A gap G is formed between the inner peripheral surface 35 a of the cylindrical main body 35 and the outer peripheral surface of the tubular filtration membrane 3. If the outer diameter of the tubular filtration membrane 3 is 5 mm, for example, the inner diameter of the cylindrical main body 35 can be 7 mm, for example. In this case, the gap G between the inner peripheral surface 35a of the cylindrical main body 35 and the outer peripheral surface of the tubular filtration membrane 3 is 1 mm. The cylindrical main body 35 is formed such that the gap G between the tubular main body 35 and the tubular filtration membrane 3 is constant.

The length of the cylindrical main body portion 35 is the same as the distance between the first partition wall 30 and the second partition wall 31. That is, the length of the cylindrical main body 35 is the same as the length of the tubular filtration membrane 3 exposed in the permeated water space S3.
The cylindrical main body 35 can be formed of, for example, a lightweight metal such as titanium or aluminum, or a plastic such as polyacetal resin. The plate thickness of the cylindrical main body 35 is preferably as thin as possible within a range that does not impair the strength of the reinforcing member 34.

  The support portion 36 is a protrusion that extends in the axial direction (extending direction) of the cylindrical main body portion 35. A plurality of support portions 36 (eight in the present embodiment) are formed in the circumferential direction of the cylindrical main body portion 35 at intervals. The height of each support portion 36 is substantially the same as the width of the gap G between the inner peripheral surface 35 a of the cylindrical main body portion 35 and the outer peripheral surface of the tubular filtration membrane 3.

In addition, although the reinforcement member 34 of this embodiment has the eight support parts 36, if it can support the tubular filtration membrane 3, it will not restrict to this. In order to secure a wider space between the tubular main body 35 and the tubular filtration membrane 3, that is, a space where the permeated water PW is discharged, it is preferable that the number is small.
Moreover, in the said embodiment, although the support part 36 is continuously formed in the axial direction of the cylindrical main-body part 35, it is not restricted to this. The support part 36 should just be able to support the tubular filtration membrane 3, ensuring this space as much as possible, without filling the space between the cylindrical main-body part 35 and the tubular filtration membrane 3. FIG. For example, the support part 36 may be formed intermittently in the axial direction. Alternatively, the tubular filtration membrane 3 may be point-supported by a plurality of support protrusions that are separated from each other.

  The through-hole 37 is an opening that allows communication between the outer peripheral side of the cylindrical main body 35 and the inner peripheral side of the cylindrical main body 35. The plurality of through holes 37 are regularly (equally) arranged on the entire outer surface of the cylindrical main body 35. It is preferable to form as many through holes 37 as possible as long as the strength of the reinforcing member 34 is not impaired. The position of the through hole 37 in the circumferential direction of the cylindrical main body portion 35 is preferably different from that of the support portion 36.

Next, the manufacturing method of the membrane module 1 of this embodiment is demonstrated.
As shown in FIG. 6, the manufacturing method M1 of the membrane module 1 of the present embodiment includes a coarse fiber amount measuring step S11 for measuring the ratio of the amount of coarse fibers contained in the treated water W3 (raw water), and the treated water W. A membrane inner diameter selection step S12 for selecting the inner diameter of the tubular filtration membrane 3 based on the amount of the coarse fibers, and a manufacturing process for preparing manufacturing members such as the tubular filtration membrane 3 and the casing 2 having the inner diameter selected in the membrane inner diameter selection step S12. It includes a member preparation step S13 and an assembly step S14 for assembling the production member.

  The coarse fiber amount measuring step S11 is a step of measuring the coarse fiber amount (mg / liter) of the water to be treated W3 introduced into the membrane separation device 13. The coarse fiber is a fiber component such as hair contained in the water to be treated W that is organic waste water.

  In the coarse fiber amount measurement step S11, a part of the water to be treated W3 can be taken out and measured by, for example, a gravimetric method. Specifically, after taking out 1 liter of water W3 to be treated, it can be calculated by removing moisture and drying it, and measuring the amount of remaining crude fiber. The measurement of the amount of crude fibers is based on, for example, a crude suspended matter analysis method in a sewage test method.

The membrane inner diameter selection step S12 is a step of selecting the inner diameter of the tubular filtration membrane 3 based on the coarse fiber amount measured in the coarse fiber amount measurement step S11.
As a result of experiments and examinations, the inventors have found that the blockage due to the coarse fibers can be suppressed by changing the inner diameter of the tubular filtration membrane 3 in accordance with the amount of the coarse fibers. Specifically, as shown in Table 1 below, by selecting the inner diameter of the tubular filtration membrane 3, blockage of the tubular filtration membrane 3 due to coarse fibers can be suppressed.

  That is, when the coarse fiber amount α is 200 mg / liter or less, the inner diameter of the tubular filtration membrane 3 is set to 5 mm. When the coarse fiber amount α is larger than 200 mg / liter and smaller than 500 mg / liter, the inner diameter of the tubular filtration membrane 3 is set to 5 mm-10 mm. When the coarse fiber amount α is 500 mg / liter or more, the inner diameter of the tubular filtration membrane 3 is set to 10 mm or more.

The production member preparation step S13 is a step of preparing the casing 2, the first partition wall 30, the second partition wall 31, the tubular filtration membrane 3, the reinforcing member 34, and the like constituting the membrane module 1. The tubular filtration membrane 3 is prepared having the inner diameter selected in the membrane inner diameter selection step S12.
The assembly step S14 is a step of assembling the manufacturing member.

Next, the effect | action of the water treatment system 10 of this embodiment is demonstrated.
First, the water to be treated W1 is treated in the biological treatment water tank 11. Specifically, the organic substance contained in the for-treatment water W1 is decomposed by microorganisms.
Next, the water to be treated W2 discharged from the biological treatment water tank 11 is stored in the raw water tank 12. When the treated water W3 discharged from the raw water tank 12 is supplied to the membrane separation device 13 via the circulation pump 21, it is sent into the tubular filtration membrane 3 of the membrane module 1. On the other hand, the permeated water space S <b> 3 in the casing 2 of the membrane module 1 becomes negative pressure by the operation of the suction pump 22. The suction pump 22 sucks in a direction substantially orthogonal to the flow of the water to be treated W3 flowing through the tubular filtration membrane 3 through the permeate discharge port 9. The permeated water PW permeated from the tubular filtration membrane 3 is stored in the storage tank 20 through the permeated water discharge port 9 and the permeated water pipe 18.

  Concentrated water W4 discharged from the membrane separator 13 is returned to the biological treatment water tank 11 through the return pipe 19 for the entire amount excluding excess sludge, and is processed again.

  According to the above embodiment, the membrane module 1 can be easily replaced even when a plurality of membrane modules 1 are arranged by placing the membrane module 1 horizontally, that is, by arranging the casing 2 so as to extend in the horizontal direction. It can be. Thereby, the maintenance of the membrane separator 13 composed of the plurality of membrane modules 1 can be facilitated.

In addition, the plurality of tubular filtration membranes 3 are reinforced by the reinforcing member 34, thereby preventing the tubular filtration membrane 3 from being bent even when the tubular filtration membrane 3 is arranged to extend in the horizontal direction. Can do.
Further, a gap G is formed between the inner peripheral surface of the reinforcing member 34 and the outer peripheral surface of the tubular filtration membrane 3 by the support portion 36 of the reinforcing member 34, so that the permeated water PW permeated from the tubular filtration membrane 3 can be reduced. The tubular filtration membrane 3 can be supported so as not to bend without impeding the flow.

  When the membrane module 1 is placed vertically, the head difference (resistance) between one end and the other end of the tubular filtration membrane 3 is increased. By placing the membrane module 1 horizontally, the head difference becomes smaller and the FLUX (outflow amount) distribution can be made smaller than when the membrane module 1 is placed vertically.

Moreover, by placing the membrane module 1 horizontally, it becomes easy to connect the plurality of membrane modules 1 in series. Even when the arrangement method of the plurality of membrane modules 1 constituting the membrane separation device 13 is arranged in series, the correspondence is easy.
Moreover, it can suppress that the tubular filtration membrane 3 is obstruct | occluded with a coarse fiber part by selecting the internal diameter of the tubular filtration membrane 3 according to the amount of coarse fibers of raw | natural water.

  Moreover, the membrane surface flow rate of the to-be-processed water W3 can be made low by forming the tubular filtration membrane 3 with the material which has hydrophilic property. The film surface flow velocity can be set to, for example, 0.15 m / s-0.30 m / s.

  When the tubular filtration membrane 3 is hydrophobic, it is necessary to increase the membrane surface flow velocity (for example, 2.5 m / s). For this reason, the circulation flow rate increases, and it becomes necessary to return the concentrated water W4 discharged from the membrane separation device 13 to the raw water tank 12 and the biological treatment water tank 11. In order to return to the raw water tank 12 and the biological treatment water tank 11, a distribution tank that distributes the concentrated water W4 to the raw water tank 12 and the biological treatment water tank 11 and a pipe that returns the concentrated water W4 to the raw water tank 12 are required. .

Since the water treatment system 10 of the present embodiment can reduce the membrane surface flow velocity, the circulating flow rate of the concentrated water W4 can be reduced. Thereby, the power of the circulation pump 21 can be reduced. Moreover, the distribution tank which distributes the concentrated water W4 to the raw | natural water tank 12 and the biological treatment water tank 11, and the piping which returns the concentrated water W4 to the raw | natural water tank 12 become unnecessary.
In addition, the diameter of the pipe can be reduced by reducing the flow rate. In addition, by reducing the flow rate, it is possible to reduce equipment such as a flow meter.

  In the above embodiment, the membrane module 1 in which the tubular filtration membranes 3 are arranged in parallel is adopted as the membrane module 1, but the present invention is not limited to this. For example, as shown in FIG. 7, a plurality of tubular filtration membranes 3 may be connected in series. That is, a plurality of U-shaped connection members 46 that connect one end of the plurality of tubular filtration membranes 3 and the other end of the tubular filtration membrane 3 so that the plurality of tubular filtration membranes 3 are connected in series. It is good also as a structure to have.

  At this time, the treated water introduction port 7 and the concentrated water discharge port 8 are directly connected to the plurality of tubular filtration membranes 3 connected in series via the connection member 53 and the connection member 54 to be treated. Water W3 may be introduced and concentrated water W4 may be discharged. In this case, since the lower header S1 and the upper header space S2 may be omitted, the configuration of the casing may be changed such that the first side wall 5 and the second side wall 6 are eliminated.

  Further, the length of the reinforcing member 34 is made longer than the interval between the first partition wall 30 and the second partition wall 31, and the reinforcing member 34 is inserted into the insertion holes 32 of the first partition wall 30 and the second partition wall 31. Also good. By setting it as such a form, the burden concerning the tubular filtration membrane 3 can be reduced more.

(Second embodiment)
Hereinafter, the reinforcing member used for the membrane module of the second embodiment of the present invention will be described with reference to the drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 8, the reinforcing member of the present embodiment is a mesh-like network structure 39 that has a cylindrical shape and is arranged on the outer peripheral side of the tubular filtration membrane 3 so as to be in contact with the tubular filtration membrane 3. The net-like structure 39 is a plastic tube formed by combining a plurality of linear plastics in a lattice pattern. A plurality of meshes 40 corresponding to the through holes 37 of the reinforcing member 34 of the first embodiment are formed in the mesh structure 39 by combining a plurality of linear plastics in a lattice shape.

As an alternative to the linear plastic, for example, a wire formed of a metal such as stainless steel can be employed. Moreover, you may employ | adopt the wire coat | covered with vinyl etc.
Further, the method of combining a plurality of linear plastics is not limited to a lattice shape, and a plurality of linear plastics may be knitted into a hexagon.
Further, as shown in FIG. 9, a net-like structure 41 obtained by processing a cylindrical plastic tube into a net shape may be adopted. That is, it is good also as a structure which formed the cylindrical-shaped cylinder main-body part 42 and the some permeated water discharge hole 43 regularly formed in the cylinder main-body part 42. FIG. The shape of the permeated water discharge hole 43 is not limited to the rectangular shape shown in FIG. 9, but may be a hexagonal shape or a circular shape as long as the permeated water PW can be sufficiently discharged.

  According to the said embodiment, compared with the reinforcement member 34 of 1st embodiment, the tubular filtration membrane 3 can be reinforced with a simpler structure. Further, the permeated water PW that has passed through the tubular filtration membrane 3 can be discharged from the mesh 40 or the permeated water discharge hole 43.

In addition, in the said embodiment, although it was set as the structure which arrange | positions the net-like structure 39 used as the reinforcement member 34 in the outer peripheral side of the tubular filtration membrane 3, it does not restrict to this. For example, as shown in FIGS. 10 and 11, the tubular filtration membrane itself may be reinforced with a metal wire 44 to form a wire-containing tubular filtration membrane 3B. The wire 44 is embedded near the center of the tubular filtration membrane 3 in the thickness direction. The wire 44 extends spirally in the extending direction of the tubular filtration membrane 3.
The method for embedding the wire 44 is not limited to the above method as long as the tubular filtration membrane 3 is reinforced by the wire 44. For example, a plurality of wires 44 may be embedded in the tubular filtration membrane 3 in a lattice pattern.

(Third embodiment)
Hereinafter, the reinforcement member used for the membrane module of 3rd embodiment of this invention is demonstrated based on drawing. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 12, the reinforcing member 34 </ b> C of the present embodiment includes a plate-like main body portion 48 having a circular plate shape, and a plurality of film insertion holes 49 formed in the plate-like main body portion 48. . The tubular filtration membrane 3 is inserted through the plurality of membrane insertion holes 49. Three reinforcing members 34 are provided at intervals in the axial direction of the casing 2.

  The outer peripheral surface 48 a of the plate-like main body 48 of the reinforcing member 34 is in contact with the inner peripheral surface of the casing 2. The reinforcing member 34 is supported by the lower part of the reinforcing member 34 coming into contact with the inner peripheral surface of the casing 2. A lower outer peripheral surface 48 a of the reinforcing member 34 functions as a reinforcing member support portion that supports the reinforcing member 34. Further, it is desirable that the cutout 55 exists in a part of the reinforcing member 34, for example, so that the permeated water PW flows in the permeated water space S3.

According to the embodiment, the plurality of tubular filtration membranes 3 are mechanically connected by the reinforcing member 34C. Thereby, even when the tubular filtration membrane 3 is arranged to extend in the horizontal direction, the tubular filtration membrane 3 can be prevented from being bent.
In addition, since the reinforcing member 34C of the present embodiment supports the tubular filtration membrane 3 only at three points in the extending direction, the permeated water PW can be more permeated than the reinforcing member 34 of the first embodiment. it can.

In the reinforcing member 34C of the above embodiment, the outer peripheral surface 48a of the reinforcing member 34C is in contact with the inner peripheral surface of the casing 2, but the present invention is not limited to this. That is, if the reinforcing member 34 </ b> C is supported by the inner peripheral surface of the casing 2, the upper portion of the reinforcing member 34 </ b> C does not have to abut on the inner peripheral surface of the casing 2. Moreover, the shape where a part of outer periphery contacts a casing, such as polygonal shape, may be sufficient, for example.
Further, the number of the reinforcing members 34C is not limited to three, and may be appropriately increased or decreased according to the strength of the tubular filtration membrane 3.

(Fourth embodiment)
Hereinafter, the design method of the water treatment system 10 of 4th embodiment of this invention is demonstrated based on drawing.
The water treatment system 10 of this embodiment is designed according to the amount of coarse fibers of the water to be treated W3. That is, the design method of the water treatment system of the present embodiment changes the arrangement of the apparatus for removing the coarse fibers according to the amount of coarse fibers in the water to be treated W3.

  As shown in FIG. 13, the water treatment system design method M2 of this embodiment includes a coarse fiber amount measurement step S21 for measuring the amount of coarse fibers in the water to be treated W3 (raw water), and the amount of coarse fibers in the water to be treated W3. And a fiber removal device selection step S22 for selecting a fiber removal device based on the above.

  The coarse fiber amount measurement step S21 is a step of measuring the coarse fiber amount (mg / liter) of the water to be treated W3 introduced into the membrane separation device 13.

Fiber removal apparatus selection process S22 is a process of selecting the fiber removal apparatus installed in the water treatment system 10 based on the coarse fiber quantity measured in the coarse fiber quantity measurement process S21.
As a result of experiments and examinations, the inventors have found that by selecting a fiber removal device according to the amount of coarse fibers, the inflow of the coarse fibers into the membrane separation device 13 can be suppressed. Specifically, as shown in Table 2 below, by selecting a fiber removing device, it is possible to suppress the inflow of coarse fibers into the membrane separation device 13.

When the coarse fiber amount α is 2,000 mg / liter or more, a centrifuge 50 is provided in the second pipe 16 between the biological treatment water tank 11 and the raw water tank 12 as shown in FIG.
When the coarse fiber amount α is larger than 500 mg / liter and smaller than 2,000 mg / liter, the trommel 51 is provided in the second pipe 16 as shown in FIG. The trommel 51 is a rotating drum having a water-permeable circumferential surface and is rotated at a low speed by a driving device. In the organic sludge supplied from one end of the trommel 51, the water in the organic wastewater is discharged as separated water from the breathable peripheral surface in the process of moving inside the inclined trommel 51 and concentrated from the other end. Organic sludge is discharged.

  When the coarse fiber amount α is 500 mg / liter or less, a screen mesh 52 is provided on the downstream side of the circulation pump 21 of the raw water supply pipe 17 as shown in FIG. As an alternative to the screen mesh 52, an auto strainer or a double strainer may be provided.

  According to the said embodiment, the inflow of the coarse fiber part to the membrane separator 13 can be suppressed. Moreover, optimization of the water treatment system 10 can be aimed at by installing the fiber removal apparatus according to the rough fiber amount of raw | natural water.

The embodiment of the present invention has been described in detail above, but various modifications can be made without departing from the technical idea of the present invention.
For example, regarding the number of the tubular filtration membranes 3, five tubular filtration membranes 3 are shown in FIG. 3 and the like, but the number of the tubular filtration membranes 3 is not limited to this.

DESCRIPTION OF SYMBOLS 1 Membrane module 2 Casing 3, 3B Tubular filtration membrane 4 Casing main body 5 1st side wall 6 2nd side wall 7 To-be-processed water introduction port 8 Concentrated water discharge port 9 Permeated water discharge port 10 Water treatment system 11 Biological treatment water tank 12 Raw water tank 13 Membrane separation device 15 First piping 16 Second piping 17 Raw water supply piping 18 Permeated water piping 19 Return piping (return line)
DESCRIPTION OF SYMBOLS 20 Storage tank 21 Circulation pump 22 Suction pump 30 1st partition 31 Second partition 32 Insertion hole 34, 34C Reinforcement member 35 Cylindrical main-body part 36 Support part 37 Through-hole 39,41 Net-like structure 40 Mesh 42 Cylindrical main-body part 43 Permeation | transmission Water discharge hole 46 Connecting member 48 Plate body 48a Outer peripheral surface (reinforcing member support)
49 Membrane insertion hole 50 Centrifuge 51 Trommel 52 Screen mesh 53 Connection member 54 Connection member 55 Notch A Axis G Gap PW Permeated water S1 First header space S2 Second header space S3 Permeated water space W1, W2, W3 Water to be treated W4 concentrated water

Claims (3)

A cylindrical casing whose axis extends in the horizontal direction;
A first partition wall provided at one end in the extending direction of the casing;
A second partition provided at the other end of the casing in the extending direction;
A plurality of layers having a single layer structure in which a hydrophilic monomer is copolymerized, extending in a horizontal direction inside the casing, one end connected to the first partition and the other end connected to the second partition. A tubular filtration membrane;
A reinforcing member for reinforcing the tubular filtration membrane in a range between the first partition wall and the second partition wall ;
The reinforcing member is
A cylindrical main body portion formed in a cylindrical shape, disposed on the outer peripheral side of the tubular filtration membrane, and formed so that a gap formed between the outer peripheral surface of the tubular filtration membrane is constant;
A plurality of support portions that are arranged apart from each other on the inner peripheral surface of the cylindrical main body portion, extend in the axial direction of the cylindrical main body portion, and support the outer peripheral surface of the tubular filtration membrane;
A membrane module having a plurality of through holes formed in the cylindrical main body . It is a manufacturing method of the membrane module of Claim 1, Comprising:
A coarse fiber amount measuring step for measuring the proportion of the coarse fiber amount contained in the water to be treated;
A membrane inner diameter selection step for selecting the inner diameter of the tubular filtration membrane based on the ratio of the amount of the coarse fibers,
A manufacturing member preparing step of preparing a manufacturing member of the membrane module, including the tubular filtration membrane having an inner diameter selected in the membrane inner diameter selecting step;
An assembly process for assembling the manufacturing member. A biological treatment water tank for treating organic substances contained in the water to be treated;
A raw water tank in which treated water discharged from the biological treatment water tank is stored;
A membrane separation apparatus comprising the membrane module according to claim 1 and separating water to be treated supplied from the raw water tank into permeate and concentrated water;
And a return line for returning the concentrated water to the biologically treated water tank, wherein the concentrated water is not returned to the raw water tank.

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