JP2022052722A - Hollow fiber membrane element, hollow fiber membrane module, water treatment device and water treatment method - Google Patents

Abstract

To provide a hollow fiber membrane element and a hollow fiber membrane module which are excellent in pressure resistance.SOLUTION: A hollow fiber membrane element has a hollow fiber membrane, a water collecting pipe, and an output port for taking out treatment water from the water collecting pipe, in which the hollow fiber membrane and the water collecting pipe are fixed to each other by a potting part, a water collecting path using the potting part and the water collecting pipe as a wall surface is provided inside the water collecting pipe, an end of the hollow fiber membrane communicates with the water collecting pipe, and a cross-sectional area in an arbitrary water collecting path cross section vertical to a longitudinal direction of the water collecting pipe is 100-350 mm2.SELECTED DRAWING: Figure 3

Description

The present invention relates to a hollow fiber membrane element, a hollow fiber membrane module, a water treatment apparatus, and a water treatment method.

Hollow fiber membrane elements are widely used in the production of sterile water, drinking water, high-grade pure water, and the like. As the hollow fiber membrane element, for example, a water collecting pipe is provided at both ends in the length direction of the hollow fiber membrane, and a tubular support column connected to the water collecting pipe in a communicating state is provided (patented). Document 1).
In a hollow fiber membrane element as in Patent Document 1, tubular protrusions communicating with the water collecting portion are provided at both ends of the water collecting pipe so as to be fitted and connected to the ends of the tubular columns. .. In the manufacture of the hollow fiber membrane element, for example, resin is injected around the protrusion with the protrusion side of the water collecting pipe facing up, and the tubular support is inserted so that the protrusion is inserted into the end of the tubular support. After inserting the end of the water pipe into the end of the water collecting pipe, the resin is cured. By inserting the tubular strut into the end of the water collection pipe with the resin injected around the protrusion, the gap between the protrusion inserted in the end of the tubular strut and the tubular strut is also filled with resin. A hollow fiber membrane element having excellent watertightness at the connection portion between the water pipe and the tubular column can be obtained.

China Utility Model No. 202006088

The hollow fiber membrane element preferably has a small pressure loss because it requires less energy for operation.
Therefore, in the hollow fiber membrane element of the type that collects water from the end of the hollow fiber membrane through the water collecting pipe, it is preferable that the cross-sectional area of the water channel inside the water collecting pipe is large because the pressure loss is small.
The hollow fiber membrane element is usually used as a hollow fiber membrane module by using a plurality of hollow fiber membrane elements. When the thickness of the hollow fiber membrane element is thin, the membrane cleanability is improved, and it is easy to increase the amount of treated water per unit volume. Therefore, if the installation location is limited, a relatively thin hollow fiber membrane element may be used.
When using a thin hollow fiber membrane element, the maximum length (height) between the bottom of the catchment pipe and the part farthest from the bottom that contacts the wall of the catchment pipe in the potting section to avoid increasing pressure loss. ) Has been lengthened to increase the cross-sectional area of the water channel inside the water collection pipe.

As a method for cleaning the hollow fiber membrane element, for example, a reverse cleaning method in which cleaning water is flowed from the water collecting pipe side to the hollow fiber membrane in order to eliminate fouling is known.
When the height of the water channel inside the water collection pipe of the relatively thin hollow fiber membrane element was increased, backwashing at high pressure (for example, 1 MPa or more) was examined, and water leakage occurred due to breakage, improving the pressure resistance. There was room for it.

An object of the present invention is to provide a hollow fiber membrane element and a hollow fiber membrane module having excellent pressure resistance.

The present invention has the following configurations.
[1] A hollow fiber membrane element having a hollow fiber membrane, a water collecting pipe, and an outlet for taking out treated water from the water collecting pipe.
The hollow fiber membrane and the water collecting pipe are fixed by a potting portion, and are fixed.
A water collecting channel having the potting portion and the water collecting pipe as a wall surface is provided inside the water collecting pipe.
The end of the hollow fiber membrane communicates with the water collecting pipe and
A hollow fiber membrane element having a cross-sectional area of 100 to 350 mm ² in any catchment channel cross section perpendicular to the longitudinal direction of the catchment pipe.
[2] The hollow fiber membrane element according to [1], wherein the length of the cross section of the catchment channel in the length direction of the hollow fiber membrane is 20 mm or less.
[3] The hollow fiber membrane element according to [1] or [2], which has at least one of a deformation suppressing member in contact with the wall of the water collecting pipe and a deformation suppressing member integrated with the water collecting pipe.
[4] The hollow fiber membrane element according to [3], wherein the deformation suppressing member is a rib.
[5] The hollow fiber membrane element according to any one of [1] to [4], wherein the water collecting pipe has a step and the step and the lower portion of the potting portion are adhered to each other.
[6] The hollow fiber membrane element according to [5], wherein the step is 0.5 mm or more.
[7] The water collecting pipe is composed of a first water collecting pipe and a second water collecting pipe.
The second water collecting pipe is located on the opposite side of the first water collecting pipe and the hollow fiber membrane in the length direction, and the first water collecting pipe and the second water collecting pipe are connected by a support.
The hollow fiber membrane element according to any one of [1] to [6].
[8] The hollow fiber membrane according to [7], wherein the water passage inside the column and the first water pipe of the first water pipe and the second water pipe of the second water pipe communicate with each other. element.
[9] Let b be the cross-sectional area on an arbitrary surface perpendicular to the longitudinal direction of the water collecting channel of the water collecting pipe, and a be the cross-sectional area on an arbitrary surface perpendicular to the longitudinal direction of the water passage of the column. The hollow fiber membrane element according to [8], which satisfies the relationship of × a ≦ b.
[10] The hollow fiber membrane element according to [9], which satisfies the following formulas (1) and (2).
a / b ₁ ≧ 0.9 ・ ・ ・ (1)
a / b ₂ ≧ 0.9 ・ ・ ・ (2)
a: Arbitrary cross-sectional area of the drainage channel of the column b ₁ : Cross-sectional area in any surface perpendicular to the longitudinal direction of the first catchment channel of the first catchment pipe b ₂ : Longitudinal direction of the second catchment channel of the second catchment pipe [11] The hollow fiber membrane element according to [9] or [10], which satisfies the following formulas (3) and (4).
0.5 × a ≦ b ₁ ... (3)
0.5 × a ≦ b ₂ ... (4)
a: Arbitrary cross-sectional area of the drainage channel of the column b ₁ : Cross-sectional area in any surface perpendicular to the longitudinal direction of the first catchment channel of the first catchment pipe b ₂ : Longitudinal direction of the second catchment channel of the second catchment pipe 12] A hollow fiber membrane module comprising a plurality of hollow fiber membrane elements according to any one of [12] [1] to [11].
[13] A water treatment device including the hollow fiber membrane module according to [12] and an air diffuser arranged below the hollow fiber membrane module.
[14] A water treatment method using the water treatment apparatus according to [13].

The present invention may have another configuration as follows.
[A1] Hollow fiber membrane and
A water collecting pipe that collects the treated water collected by the hollow fiber membrane,
A hollow fiber membrane element having an outlet for taking out treated water from the water collecting pipe.
The hollow fiber membrane and the water collecting pipe are fixed by a potting portion, and are fixed.
A water collecting channel having the potting portion and the water collecting pipe as a wall surface is provided inside the water collecting pipe.
The water collecting pipe has a support column extending parallel to the hollow fiber membrane.
The support column has a water passage that communicates with the water collection channel inside.
The cross-sectional area of the water collecting channel on the plane perpendicular to the longitudinal direction of the water collecting pipe is equal to or less than the cross-sectional area of the water passage.
Hollow fiber membrane element.
[A2] Assuming that the cross-sectional area of the catchment channel is b and the cross-sectional area of the water passage is a.
0.5 × a ≦ b
The hollow fiber membrane element according to [A1], which satisfies the relationship of.
[A3] Let W be the maximum length between the wall surfaces of the water collecting pipes facing each other at intervals in the lateral direction of the water collecting pipes.
Let H be the maximum length in the longitudinal direction of the hollow fiber membrane perpendicular to the longitudinal direction of the water collecting pipe from the portion of the potting portion in contact with the wall surface farthest from the bottom surface of the collecting channel to the bottom surface.
The hollow fiber membrane element according to [A1] or [A2], which satisfies the relationship of H ≦ 1.2 × W.
[A4] The water collecting pipes are a first water collecting pipe provided on one side of the hollow fiber membrane in the longitudinal direction and having a first collecting channel, and a second collecting channel provided on the other side of the hollow fiber membrane in the longitudinal direction. Has a second water collecting pipe and has
One of [A1] to [A3], wherein the first water collecting pipe and the second water collecting pipe are connected by the support column, and the first water collecting channel and the second water collecting channel communicate with the water passage. The hollow fiber membrane element described.
[A5] The hollow fiber membrane element according to any one of [A1] to [A4], wherein ribs are arranged in the lower part of the water collecting pipe.
[A6] The hollow fiber membrane element according to [A5], wherein the ribs are arranged over 70% or more of the length in the longitudinal direction of the catchment channel.
[A7] Hollow fiber membrane and
A water collecting pipe that collects the treated water collected by the hollow fiber membrane,
A hollow fiber membrane element having an outlet for taking out treated water from the water collecting pipe.
The hollow fiber membrane and the water collecting pipe are fixed by a potting portion, and are fixed.
A water collecting channel having the potting portion and the water collecting pipe as a wall surface is provided inside the water collecting pipe.
The end of the hollow fiber membrane communicates with the water collecting pipe and
The cross-sectional area of the catchment channel on the plane perpendicular to the longitudinal direction of the catchment pipe is 100 to 350 mm ² .
The length of the water collecting channel in the longitudinal direction of the hollow fiber membrane on the plane perpendicular to the longitudinal direction of the water collecting pipe is 20 mm or less.
Hollow fiber membrane element.
[A8] Hollow fiber membrane and
A water collecting pipe that collects the treated water collected by the hollow fiber membrane,
A hollow fiber membrane element having an outlet for taking out treated water from the water collecting pipe.
The hollow fiber membrane and the water collecting pipe are fixed by a potting portion, and are fixed.
A water collecting channel having the potting portion and the water collecting pipe as a wall surface is provided inside the water collecting pipe.
The end of the hollow fiber membrane communicates with the water collecting pipe and
The cross-sectional area of the water collecting channel perpendicular to the longitudinal direction of the water collecting pipe is 100 to 350 mm ² .
It has a member that is in contact with and / or is integrated with the wall of the water pipe and suppresses deformation of the wall.
Hollow fiber membrane element.
[A9] The water collecting pipe has a first water collecting pipe and a second water collecting pipe.
The second water collecting pipe is located on the opposite side of the first water collecting pipe and the hollow fiber membrane in the longitudinal direction, and the first water collecting pipe and the second water collecting pipe are connected by a support column [A7]. Or the hollow fiber membrane element according to [A8].
[A10] The hollow fiber membrane element according to [A9], wherein the support column communicates with the water collecting portion inside the first water collecting pipe and the second water collecting part inside the second water collecting pipe. ..
[A11] The ratio a / b ₁ of the cross-sectional area a of the portion through which the water of the column passes and the cross-sectional area b1 of the portion through which the water of the _first water collecting pipe passes, and the cross-sectional area a of the portion through which the water of the column passes and the above. The hollow fiber membrane element according to [A10], wherein the ratio a / b ₂ of the cross-sectional area b ₂ of the portion through which water passes in the second water collecting pipe simultaneously satisfies the formulas (1) and (2).
a / b ₁ ≧ 0.9 ・ ・ ・ (1)
a / b ₂ ≧ 0.9 ・ ・ ・ (2)
[A12] The hollow fiber membrane element according to any one of [A1] to [A11], wherein the surface roughness of the adhesive surface of the water collecting pipe with the potting portion is Ra 6.3 to 25.
[A13] The hollow fiber membrane element according to any one of [A1] to [A12], wherein the adhesive surface of the water collecting pipe with the potting portion has irregularities.
[A14] The hollow fiber membrane element according to any one of [A1] to [A13], which has a step at the lower part of the adhesive surface of the water collecting pipe with the potting portion.
[A15] The hollow fiber membrane element according to [A14], wherein the step is 0.5 mm or more.
[A16] A hollow fiber membrane module including a plurality of hollow fiber membrane elements according to any one of [A1] to [A15].

According to the present invention, it is possible to provide a hollow fiber membrane element and a hollow fiber membrane module having excellent pressure resistance.

It is a perspective view which showed an example of the hollow fiber membrane element of this invention. It is a front view of the hollow fiber membrane element of FIG. FIG. 2 is a cross-sectional view taken along the line AA of the hollow fiber membrane element of FIG. This is a modification of the hollow fiber membrane element of the present invention. This is a modification of the hollow fiber membrane element of the present invention. This is a modification of the hollow fiber membrane element of the present invention. This is a modification of the hollow fiber membrane element of the present invention. This is a modification of the hollow fiber membrane element of the present invention. This is a modification of the hollow fiber membrane element of the present invention. This is a modification of the hollow fiber membrane element of the present invention. This is a modification of the hollow fiber membrane element of the present invention. It is BB sectional view of the hollow fiber membrane element of FIG. 4 is a cross-sectional view taken along the line CC of the hollow fiber membrane element of FIG. This is a modification of the hollow fiber membrane element of the present invention.

When "-" is used to indicate a numerical range, the numerical values before and after "-" are included as the lower limit value and the upper limit value.
Further, in the present invention, "arbitrary" is synonymous with "at least a part".

1. 1. Hollow fiber membrane element Hereinafter, an example of the hollow fiber membrane element of the present invention will be described with reference to the drawings. It should be noted that the dimensions and the like of the figures exemplified in the following description are examples, and the present invention is not necessarily limited to them, and the present invention can be appropriately modified without changing the gist thereof. ..

1.1 Structure of Hollow Fiber Membrane Element The hollow fiber membrane element 1 of the present embodiment has a hollow fiber membrane 11, a water collecting pipe, and an outlet 40a for taking out treated water from the water collecting pipe, as shown in FIGS. 1 and 2. , 40b and.
In the hollow fiber membrane element 1 shown in FIGS. 1 and 2, the water collecting pipe is composed of a first water collecting pipe 12 having a first water collecting channel 20e inside and a second water collecting pipe 14 having a second water collecting channel 20f inside. It is composed. The first water collecting pipe 12 and the second water collecting pipe 14 are respectively arranged on opposite sides in the length direction of the hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10 in which a plurality of hollow fiber membranes 11 are bundled. The ends of both the first water collecting pipe 12 and the second water collecting pipe 14 are connected to each other by the first tubular column 16 and the second tubular column 18, respectively.
In the hollow fiber membrane element 1, outlets 40a and 40b are formed at both ends of the second water collecting pipe 14 in the longitudinal direction, respectively. The outlet may be located anywhere as long as the treated water collected in the water collecting pipe can be taken out through the hollow fiber membrane, or may be present on the support column.

1.2 Hollow fiber membrane The hollow fiber membrane 11 is usually used as a hollow fiber membrane sheet-like material 10 in which a plurality of hollow fiber membranes 11 are bundled in a sheet shape. The first water collecting pipe 12 is provided on the side of the first opening end portion 10a in the length direction of the hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10. The second water collecting pipe 14 is provided on the side of the second opening end 10b opposite to the first opening end 10a in the length direction of the hollow fiber membrane sheet-like material 10.

The first tubular strut 16 is arranged on one side in the width direction of the hollow fiber membrane sheet-like object 10, and the first end portion 17a of the first tubular strut 16 is attached to the first end portion 13a of the first water collecting pipe 12. It is connected and the second end 17b of the first tubular column 16 is connected to the first end 15a of the second water collecting pipe 14. The second tubular strut 18 is arranged on the other side of the hollow fiber membrane sheet-like object 10 in the width direction, and the first end portion 19a of the second tubular strut 18 is attached to the second end portion 13b of the first water collecting pipe 12. It is connected and the second end 19b of the second tubular column 18 is connected to the second end 15b of the second water collecting pipe 14.
The hollow fiber membrane element 1 is arranged so that the first water collecting pipe 12 is on the lower side and the second water collecting pipe 14 is on the upper side, and the length direction of each hollow fiber membrane 11 of the hollow fiber membrane sheet 10 is the vertical direction. Can be done.

The hollow fiber membrane sheet-like material 10 is formed by bundling a plurality of hollow fiber membranes 11 in parallel with each other in a sheet shape. The number of hollow fiber membranes 11 in the hollow fiber membrane sheet 10 is not particularly limited, and can be appropriately set according to the film area, for example, 1000 to 6000, 2000 to 5000, and the like.
The hollow fiber membrane sheet-like material 10 of this example is a laminated body in which a plurality of sheets in which a plurality of hollow fiber membranes 11 are aligned are laminated. In the present invention, the hollow fiber membrane sheet-like material may be a laminated body of such a plurality of sheets, or may be composed of one sheet.

Examples of the material of the hollow fiber membrane include polysulfone resin, polyacrylonitrile, cellulose derivative, polyolefin such as polyethylene and polypropylene, polyvinylidene fluoride (PVDF) and fluororesin such as polytetrafluoroethylene, polyamide, polyester and polymethacrylate. , Polyacrylate and the like. Further, those having a substituent introduced into a part of these resins may be used. The material of the hollow fiber membrane may be one kind or two or more kinds.

For example, a plurality of hollow fiber membranes 11 may be used to form a hollow fiber membrane sheet by the method for producing a hollow fiber membrane sheet described in Japanese Patent No. 5919672.

1.3 Water collecting pipe As shown in FIG. 3, the first water collecting pipe 12 has a long length in which the surfaces of the first water collecting pipe 12 face each other in the lateral direction of the first water collecting pipe 12 and extend in the longitudinal direction of the first water collecting pipe 12. A pair of side wall portions 20a and 20b and a bottom portion 20c having a semicircular cross section connecting one end portions of the side wall portions 20a and 20b (lower ends in FIG. 3) are provided. The shape of the cross section orthogonal to the longitudinal direction of the first water collecting pipe 12 is U-shaped. On the side of the first water collecting pipe 12 opposite to the bottom portion 20c, a slit-shaped opening 20d extending in the longitudinal direction is formed between the first end portion 13a and the second end portion 13b. The first opening end portion 10a of the hollow fiber membrane sheet-like material 10 is inserted into the opening portion 20d of the first water collecting pipe 12.

Inside the bottom portion 20c, a pair of wall surfaces 50a and 50b and a pair of wall surfaces 50a and 50b facing each other at a distance in the lateral direction of the first water collecting pipe 12 and extending in the longitudinal direction of the first water collecting pipe 12 A bottom surface 50c connecting the lower ends is formed. The wall surface 50a and the wall surface 50b are arranged at intervals of a maximum length W in the lateral direction of the first water collecting pipe 12. The bottom surface 50c is a semicircle having a cross-sectional shape perpendicular to the longitudinal direction of the first water collecting pipe 12 and having a radius W / 2.

As shown in FIG. 3, the first opening end portion 10a of the hollow fiber membrane sheet-like material 10 is housed in the potting case 23 and fixed to the potting case 23 by the potting portion 23b made of a cured product of the potting resin. Then, it is inserted into the opening 20d of the first water collecting pipe 12. The potting case 23 is fixed to the first water collecting pipe 12 by a potting portion 22a made of a cured product of the potting resin. Further, the portion of the hollow fiber membrane sheet-like material 10 on the opening 20d side of the potting case 23 at the first opening end 10a is fixed to the first water collecting pipe 12 by the potting portion 23a made of a cured product of the potting resin. There is.
In this way, the hollow fiber membrane 11 and the first water collecting pipe 12 are fixed by the potting portions 22a, 23a, 23b. The bottom 20c side of the potting portions 22a and 23b in the first catchment pipe 12 is the first catchment channel 20e (collection channel). That is, the first water collecting pipe 12 has a first water collecting channel 20e having a potting portion 22a, 23b and a first water collecting pipe 12 as a wall surface inside the first water collecting pipe 12.
In the first opening end portion 10a of the hollow fiber membrane sheet-like material 10, the inside of each hollow fiber membrane 11 communicates with the first water collecting channel 20e of the first water collecting pipe 12.

The cross-sectional area of any first catchment channel 20e perpendicular to the longitudinal direction of the first catchment pipe 12 is 100 mm 2-350 mm ² , preferably 150 mm ^2-300 mm ² , more preferably ^{250 mm} 2-280 mm. It is ² . When the cross-sectional area is within this range, it is possible to secure excellent pressure resistance while suppressing an increase in flow resistance within an acceptable range.
As the first water collecting pipe 12, it is preferable that the cross-sectional area of the first water collecting channel 20e is within the above range at any position in the longitudinal direction of the first water collecting pipe 12. However, the present invention is not limited, and the first catchment pipe 12 may have only a part of the cross-sectional area in the longitudinal direction of the first catchment channel 20e in the above range.

The length H (also referred to as the height H of the catchment channel) in the length direction of the hollow fiber membrane 11 in the cross section of the catchment channel perpendicular to the longitudinal direction of the first catchment pipe 12 is preferably 20 mm or less, more preferably. It is 15 to 20 mm, more preferably 16 mm to 20 mm, and particularly preferably 17 mm to 19 mm. As shown in FIG. 3, the length H is the bottom surface of the potting portion 23b in contact with the wall surfaces 50a and 50b in the length direction of the hollow fiber membrane 11 having a cross section perpendicular to the longitudinal direction of the first water collecting pipe 12. It is the distance from the end face on the 50c side to the bottom of the bottom surface 50c.
When the height H of the catchment channel is 20 mm or less, the pressure resistance is further improved, and water leakage is less likely to occur even if backwashing at high pressure is performed.

It is preferable that the maximum length W of the interval in the lateral direction on the wall surfaces 50a and 50b and the height H of the catchment channel satisfy the relationship of H ≦ 1.2 × W. Within this range, it becomes easy to suppress the retention of water.
Further, when the maximum length W of the catchment channel is widened, a large amount of membrane can be packed in the catchment pipe, and the amount of water that can be treated per unit time increases. Furthermore, the water inside the catchment pipe is easily updated, and the water accumulated in the lower part of the catchment channel flows out to improve the water quality.

As another means for improving the pressure resistance of the first water collecting pipe 12, as shown in FIGS. 3A to 3H, a deformation suppressing member 21a that suppresses deformation of the wall of the first water collecting pipe 12 may be provided. Further, a member 21 that supports the deformation suppressing member 21a may be further provided. The deformation suppressing member 21a suppresses deformation in which the water collecting channel tends to expand outward even when backwashing is performed at high pressure, and the pressure resistance is further improved, so that water leakage is less likely to occur. Further, by installing the deformation suppressing member 21a, even if the hollow fiber membrane element 1 is hit, only the deformation suppressing member 21a is damaged, and the water collecting channel is less likely to be damaged.
It is preferable that the deformation suppressing member 21a is arranged over 70% or more of the length in the longitudinal direction of the first water collecting pipe 12.
The deformation suppressing member 21a is preferably a reinforcing rib, but may be a reinforcing member other than the rib as long as it can suppress the deformation of the wall of the first water collecting pipe 12.

The deformation suppressing member 21a may be provided on the outside of the first water collecting pipe 12 as shown in FIGS. 3A, 3B, 3F to 3H, and the first collecting member 21a may be provided as shown in FIGS. 3C to 3E. It may be provided inside the water pipe 12, that is, on the side of the first water collecting channel 20e.
Further, the deformation suppressing member 21a may be provided as a separate member from the first water collecting pipe 12 so as to be in contact with the wall of the water collecting pipe, and is an integrated member connected to the first water collecting pipe 12. May be good.

As shown in FIGS. 3A to 3H, the deformation suppressing member 21a is defined by the distance between the outer side surfaces of the pair of side wall portions 20a and 20b in the cross section perpendicular to the longitudinal direction of the first water collecting pipe 12. It is formed with a width that does not greatly exceed. Therefore, the first water collecting pipe 12 having the deformation suppressing member 21a does not increase the overall size. For example, even when a collision occurs during maintenance work, the damage is suppressed because it is structurally reinforced, and the deformation suppressing member 21a bears the impact when the collision occurs. It becomes possible to replace it with.

As shown in FIG. 3, the first water collecting pipe 12 has a step 20 g on the inner surface of the pair of side wall portions 20a and 20b, and the lower portion of the potting portion 22a is adhered to the surface of the step 20 g facing the opening 20d side. Is preferable. The presence of such a step of 20 g is preferable in that the adhesion range in the shear direction increases with respect to the force that the wall of the catchment channel at the time of pressurization tends to spread outward. Further, since the adhesive area is increased and the adhesive strength is improved, the adhesive strength between the water collecting pipe and the potting portion is increased, and it becomes easy to suppress the peeling of the adhesive portion due to the impact when hit.
The width of the step 20 g in the lateral direction of the first water collecting pipe 12 is preferably 0.5 mm or more, more preferably 1.5 mm or more, and more preferably 2.0 mm to 3.0 mm.

The surface roughness of the adhesive surface of the first water collecting pipe 12 with the potting portion 22a is preferably Ra 6.3 to 25 as the arithmetic average roughness Ra defined in JIS B 0601: 2001. When the surface roughness is within this range, the adhesive strength between the first water collecting pipe 12 and the potting portion 22a becomes higher, the durability of the hollow fiber membrane element 1 is further improved, and a plurality of high-pressure backwashing is performed. Will be easier to withstand. In addition, the adhesive strength between the water collecting pipe and the potting portion is increased, and it becomes easy to suppress the peeling of the adhesive portion due to the impact when hit.
The surface roughness is divided into a case where the surface is roughened on the main body of the water collecting pipe and a case where the surface is roughened on the molding die of the water collecting pipe. When it is applied to the main body of the water collection pipe, sandblasting or filing can be mentioned, and when it is applied to the mold of the water collecting pipe, shot blasting treatment or chemical corrosion treatment can be mentioned.

It is preferable that the adhesive surface of the first water collecting pipe 12 with the potting portion 22a has irregularities. When the adhesive surface has irregularities, the adhesive strength between the first water collecting pipe 12 and the potting portion 22a becomes higher, the durability of the hollow fiber membrane element 1 is further improved, and it can withstand a plurality of high-pressure backwashing. It will be easier. In addition, the adhesive strength between the water collecting pipe and the potting portion is increased, and it becomes easy to suppress the peeling of the adhesive portion due to the impact when hit.
Examples of the unevenness of the adhesive surface include a square shape and a corrugated shape. The height (height difference) of the unevenness is preferably 0.3 mm to 1.0 mm, more preferably 0.4 mm to 0.6 mm. When the unevenness is in this range, it is preferable in that the adhesive force of the potting liquid applied to the adhesive surface is improved and it is easy to prevent the potting liquid from flowing into the catchment channel when the potting liquid is injected.

The contents described above for the first water collecting pipe 12 in "1.3 Water collecting pipe" include the mode of inserting the open end of the hollow fiber membrane sheet into the water collecting pipe, the cross-sectional area of the collecting channel, and the like. 2 It also corresponds to the water collecting pipe 14. In the hollow fiber membrane element 1, the second water collecting pipe 14 is a first water collecting pipe on the side opposite to the first water collecting pipe 12 side in the length direction of each hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10. No. 12 is arranged upside down, that is, with the opening facing downward. The second opening end portion 10b of the hollow fiber membrane sheet-like material 10 is inserted into the slit-shaped opening of the second water collecting pipe 14, and is fixed by the potting portion in a state where the end faces of the respective hollow fiber membranes 11 are open. ..
The first water collecting pipe 12 and the second water collecting pipe 14 may have the same mode or different modes, but it is preferable that the first water collecting pipe 12 and the second water collecting pipe 14 have the same mode.

The material of the water collecting pipe is preferably one having excellent mechanical strength and durability, for example, polycarbonate, polysulfone, polyolefin, PVC (polyvinyl chloride), acrylic resin, ABS resin, modified PPE (polyphenylene ether) and the like. Can be mentioned. The material of the water collecting pipe may be one type or two or more types.

Examples of the potting resin forming the potting portion include an epoxy resin, an unsaturated polyester resin, a polyurethane resin, a silicone-based filler, and various hot melt resins. The potting resin forming the potting portion may be one kind or two or more kinds.

1.4 Strut FIG. 4 is a cross-sectional view taken along the line BB of the hollow fiber membrane element of FIG.
As shown in FIG. 4, the first tubular column 16 has a water passage 61, which is a portion through which water passes. The water passage 61 inside the first tubular column 16 and the first water pipe 20e inside the first water pipe 12 and the second water pipe 20f inside the second water pipe 14 communicate with each other. There is. Similarly, the second tubular strut 18 has a water passage, which is a portion through which water passes. The water passage inside the second tubular column 18 and the first water pipe 20e inside the first water pipe 12 and the second water pipe 20f inside the second water pipe 14 communicate with each other. ..

The cross-sectional area of the water collecting channel of the water collecting pipe is preferably equal to or less than the cross-sectional area of the water passage of the column. If the cross-sectional area of the catchment channel of the catchment pipe is larger than the cross-sectional area of the drainage channel of the column, in other words, if the cross-sectional area of the channel of the column is smaller than the cross-sectional area of the catchment channel of the catchment pipe, a suction pump or the like. The suction pressure when collecting the treated water collected by the hollow thread film through the water passage to the water collection channel is lost in the water flow channel and is not sufficiently applied to the water collection channel, so that the water permeability is lowered. there is a possibility. On the other hand, when the cross-sectional area of the water collecting channel of the water collecting pipe is equal to or less than the cross-sectional area of the water passage of the column, it becomes easy to suppress the pressure loss in the water passage and maintain the water permeability.
As described above, by setting the cross-sectional area of the catchment channel in the plane perpendicular to the longitudinal direction of the catchment pipe to be equal to or less than the cross-sectional area of the water passage, it becomes easy to suppress the pressure loss in the water passage and maintain the water permeability. .. In addition, since there is a dimensional allowance in the height direction while ensuring the cross-sectional area of the catchment channel without changing the size of the hollow fiber membrane element, a deformation suppressing member should be installed at the bottom of the catchment channel or the catchment pipe. Will be easier.

Assuming that the cross-sectional area of an arbitrary surface perpendicular to the longitudinal direction of the water passage of the column is a and the cross-sectional area of any surface perpendicular to the longitudinal direction of the water collecting channel of the water collecting pipe is b, 0.5 × a ≦ b It is preferable to satisfy the relationship. When the cross-sectional area b of the catchment channel is smaller than 0.5 × a, the pressure loss in the catchment channel may be large and the water permeability may decrease. Therefore, by satisfying the relationship of 0.5 × a ≦ b, it becomes easy to maintain the water permeability of each hollow fiber membrane 11.

The ratio a / b ₁ of the cross-sectional area a of the water passage 61 of the first tubular support 16 to the cross-sectional area b ₁ of the first water collecting channel 20e of the first water collecting pipe 12 and the disconnection of the water passage 61 of the first tubular support 16. The ratio a / b ₂ of the area a and the cross-sectional area b2 of the _second catchment channel 20f of the second catchment pipe 14 is preferably 0.7 or more, more preferably 0.9 or more, respectively, and the formula (1) and the formula. It is preferable to satisfy (2) at the same time.
a / b ₁ ≧ 0.9 ・ ・ ・ (1)
a / b ₂ ≧ 0.9 ・ ・ ・ (2)
When the ratio a / b ₁ and the ratio a / b ₂ are 0.7 or more, the pressure loss of the water passage 61 of the first tubular column 16 in the hollow fiber membrane element 1 tends to be smaller, which is preferable.
The ratio of the cross-sectional area of the water passage of the second tubular support 18 to the cross-sectional area of the first water collecting channel 20e of the first water collecting pipe 12, and the cross-sectional area of the water passage of the second tubular support 18 and the second water collecting pipe. The same applies to the ratio to the cross-sectional area of the two catchment channels 20f.

The cross-sectional area a of the water passage 61 of the first tubular column 16, the cross-sectional area b1 of the first water collecting channel 20e of the first water collecting pipe 12, and the cross-sectional area b2 of the _second water collecting channel 20f of the _second water collecting pipe 14. Is more preferably satisfied with the equations (3) and (4) at the same time. This makes it even easier to maintain the water permeability of each hollow fiber membrane 11.
0.5 × a ≦ b ₁ ... (3)
0.5 × a ≦ b ₂ ... (4)

The cross-sectional area of the water passage of the column may be, for example, 150 mm ² to 400 mm ² .
The form of the support is not particularly limited, and examples thereof include a square cylinder and a cylinder.
The material of the column is not particularly limited, and examples thereof include stainless steel (SUS) and the like.

1.5 Protruding portion The first end portion 13a of the first catchment pipe 12 has a tubular portion 24a communicating with the first catchment channel 20e and an opening of the tubular portion 24a, as shown in FIGS. 4 and 5. It includes a tubular protrusion 24b provided so as to protrude toward the portion 20d, and a peripheral wall portion 24c provided so as to surround the periphery of the protrusion 24b. Two of the four peripheral wall portions 24c are provided on both sides of the protrusion 24b on the tubular portion 24a in the longitudinal direction in the longitudinal direction, away from the protrusion 24b and facing each other. The remaining two of the four peripheral wall portions 24c are provided on both sides of the first water collecting pipe 12 of the protrusion 24b on the tubular portion 24a in the lateral direction, facing each other at a distance from the protrusion 24b. , Each is a continuous wall integrated with the side wall portions 20a and 20b.
Of the four peripheral wall portions 24c surrounding the protrusion 24b, the upper end of the peripheral wall portion 24c on the central side in the longitudinal direction of the first water collecting pipe 12, that is, on the side close to the first opening end portion 10a of the hollow fiber membrane sheet-like material 10. , It is slightly lower than the upper ends of the side wall portions 20a and 20b. Further, the upper ends of the remaining three peripheral wall portions 24c, that is, the peripheral wall portions 24c on the end face side of the first water collecting pipe 12 and the pair of peripheral wall portions 24c facing each other in the lateral direction are at the same height as the upper ends of the side wall portions 20a and 20b. It has become.

The tubular protrusion 24b provided at the first end 13a of the first water collecting pipe 12 is a portion for connecting to the first tubular support 16. The inside of the protrusion 24b communicates with the inside of the tubular portion 24a. The shape of the protrusion 24b is not particularly limited, and examples thereof include a square cylinder and a cylinder.

The height of the protrusion 24b is preferably 5 to 30 mm, more preferably 10 to 20 mm. When the height of the protrusion 24b is equal to or higher than the lower limit of the above range, the connection strength between the protrusion 24b and the first tubular support 16 can be easily increased. When the height of the protrusion 24b is equal to or less than the upper limit of the above range, the molding processability is excellent.

The aspect of the second end 13b of the first water collecting pipe 12 is the same as that of the first end 13a, and includes a tubular protrusion for connecting to the second tubular column 18, and the preferred embodiment is also the same. Is.
The embodiments of the first end portion 15a and the second end portion 15b of the second water collecting pipe 14 are the same as those of the second end portion 13b of the first water collecting pipe 12, and the preferred embodiments are also the same.

1.6 Outlet port An outlet for taking out treated water is formed on at least one end surface of the first water collecting pipe 12 and the second water collecting pipe 14. In the end surface of the first water collecting pipe 12 on the first end portion 13a side of this example, the opening 24d of the tubular portion 24a is closed by the lid member 25. The opening on the end face of the water collecting pipe may be used as an outlet for taking out the treated water without closing it with the lid member.

1.7 Tubular sleeve In FIGS. 4 and 5, the protrusion 24b of the first end 13a of the first water collecting pipe 12 is inside the first end 17a of the first tubular strut 16 with the tubular sleeve 26 attached. Although inserted, the tubular sleeve 26 is optional. Further, the tubular sleeve 26 may be integrally molded with the first water collecting pipe.
When the tubular sleeve 26 is attached, the first is in a state where the inside of the first tubular support 16 and the first water collecting channel 20e inside the first water collecting pipe 12 communicate with each other via the protrusion 24b and the tubular sleeve 26. The first end portion 17a of the tubular support 16 and the first end portion 13a of the first water collecting pipe 12 are connected to each other.
Similarly, the protrusion of the second end 13b of the first water collecting pipe 12 is inserted into the first end 19a of the second tubular strut 18 with the tubular sleeve attached, and is inserted into the inside of the second tubular strut 18. The first end 19a of the second tubular column 18 and the second end of the first water collecting pipe 12 in a state where the first water collecting channel 20e inside the first water collecting pipe 12 communicates with each other via a protrusion and a tubular sleeve. It may be connected to 13b. The tubular sleeve is optional. Further, the tubular sleeve 26 may be integrally molded with the second water collecting pipe.
The protrusion of the first end portion 15a of the second water collecting pipe 14 is inserted into the second end portion 17b of the first tubular strut 16 with the tubular sleeve attached, and the inside of the first tubular strut 16 and the second collection. In a state where the second water collecting channel 20f inside the water pipe 14 communicates with the second water collecting channel 20f via the protrusion and the tubular sleeve, the second end portion 17b of the first tubular column 16 and the first end portion 15a of the second water collecting pipe 14 are connected. It may be connected.
The protrusion of the second end 15b of the second water collecting pipe 14 is inserted into the second end 19b of the second tubular support 18 with the tubular sleeve attached, and the inside of the second tubular support 18 and the second collection. The second end 19b of the second tubular column 18 and the second end 15b of the second water collecting pipe 14 are in a state where the second water collecting channel 20f inside the water pipe 14 communicates with the second water collecting channel 20f via the protrusion and the tubular sleeve. It may be connected.

1.8 Resin The resin 30 is filled around the first end 17a of the first tubular column 16 inside the peripheral wall 24c of the first end 13a of the first water collecting pipe 12. As a result, the insertion portion 28 of the first tubular column 16 is fixed in a state of being hermetically sealed with the resin 30 so that the inside and the outside thereof are separated from each other.
It is preferable that the gap between the first tubular column 16 and the protrusion 24b in the insertion portion 28 is watertightly sealed with the resin 30.

The resin 30 is not particularly limited, and a known curable resin can be used without particular limitation. As the resin 30, a hard resin having a shore A hardness of 80 or more measured in accordance with JIS C 2105 is preferable because it has a higher adhesive force with a tubular column and is excellent in watertightness. When the resin 30 is a hard resin, the shore A hardness is preferably 99 or less because the portion of the resin 30 is not easily damaged. As the resin 30, a soft resin having a shore A hardness of less than 80 may be used.

Examples of the hard resin include epoxy resin, unsaturated polyester resin, polyurethane resin, silicone-based filler, and various hot melt resins.
Examples of the soft resin include polyurethane resin, silicone-based filler, and various hot melt resins.

It is preferable that the protrusion 24b becomes thinner toward the tip. This makes it easier to insert the first tubular column 16, and also makes it easier to prevent the resin 30 injected around the protrusion 24b from being peeled off when the first tubular column 16 is inserted. In addition, it becomes easy to remove the mold when the first water collecting pipe 12 is manufactured by injection molding.

The outer surface of the first end 17a of the first tubular column 16 is preferably blasted. In the present invention, it is preferable that the outer surfaces of the ends of the first tubular column and the second tubular column are blasted. The outer surface of the end portion of the first tubular strut and the second tubular strut is watertightly sealed so that the inside and the outside communicating with each other are separated from the insertion portion in which the protrusion is inserted in the end portion. Contact with the resin to be fixed. Since the outer surfaces of the ends of the first tubular column and the second tubular column are blasted, the adhesion between the tubular column and the resin is improved, and the strength of the hollow fiber membrane element is improved.
The blasting method is not particularly limited.

1.9 blocks Further, in this example, blocks 32 and 34 are provided on both sides in the longitudinal direction of the first end portion 17a of the first tubular column 16 inside the peripheral wall portion 24c of the first water collecting pipe 12. .. The blocks 32 and 34 are provided in a state of being embedded in the resin 30 filled inside the peripheral wall portion 24c. As a result, even when a load is applied to the support column, the support column is prevented from falling and being damaged.

The form of the block is not particularly limited, and examples thereof include a tubular body and a columnar body.
The material of the block is not particularly limited, and examples thereof include the same materials as those mentioned as the material of the water collecting pipe.
A rectangular parallelepiped part of the water collecting pipe may be formed by integral molding so as to have the same function as the block.

Further, in the present invention, the first through the first opening end of the hollow fiber membrane sheet-like material on the first end side of the first opening end of the hollow fiber membrane sheet-like material in the longitudinal direction of the first water collecting pipe. A first closing portion is provided to block the flow of the treated water flowing into the collecting channel of the collecting pipe to the first tubular column, and the second opening end of the hollow fiber membrane sheet-like material in the longitudinal direction of the second collecting pipe. On the side of the second end, there is a second closing part that blocks the flow of the treated water that has flowed into the collecting channel of the second collecting pipe through the second opening end of the hollow fiber membrane sheet-like material to the second tubular column. It is preferable that it is provided. As a result, it is possible to prevent the portion of the hollow fiber membrane sheet-like material used for processing from being biased, and the hollow fiber membrane sheet-like material can be efficiently used for processing as a whole.

For example, in this example, as shown in FIG. 2, the first end 13a side and the second water collecting pipe of the hollow fiber membrane sheet-like material 10 in the longitudinal direction of the first water collecting pipe 12 with respect to the first opening end 10a. The first closed portion 36 and the second closed portion 38 are provided on the second end portion 15b side of the second opening end portion 10b of the hollow fiber membrane sheet-like material 10 in the longitudinal direction of 14. The outlets 40a and 40b for taking out the treated water are formed on the end faces of the first end portion 15a and the second end portion 15b of the second water collecting pipe 14.

The first closing portion 36 is a portion that blocks the flow of the treated water that has flowed into the first catchment channel 20e through the first opening end portion 10a of the hollow fiber membrane sheet-like material 10 to the first tubular column 16. The second closing portion 38 is a portion that blocks the flow of the treated water that has flowed into the second collecting channel 20f through the second opening end portion 10b of the hollow fiber membrane sheet-like material 10 to the second tubular column 18.
The form of the first closed portion 36 and the second closed portion 38 is not particularly limited as long as it can block the flow of the treated water.

In such an embodiment, as shown in FIG. 2, the treated water collected in the first water collecting channel 20e of the first water collecting pipe 12 below from the lower portion of each hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10. Is sent to the second end portion 15b of the upper second water collecting pipe 14 through the second tubular support 18 and taken out from the take-out port 40b. Further, the treated water collected in the second water collecting channel 20f of the second water collecting pipe 14 above from the upper portion of each hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10 is the first end portion of the second water collecting pipe 14. It is sent to 15a and taken out from the take-out port 40a. As a result, the hollow fiber membrane sheet-like material 10 can be efficiently used for processing as a whole.

Further, for example, as shown in FIG. 6, a first closed portion 36 is provided in the center in the longitudinal direction of the first water collecting pipe 12, and a second closed portion 38 is provided in the center in the longitudinal direction of the second water collecting pipe 14. The outlets 40a and 40b for taking out the treated water may be formed on the end faces of the first end portion 15a and the second end portion 15b of the second water collecting pipe 14.

In this configuration, the first closing portion 36 is the second end portion 13b of the treated water that has flowed into the first catchment channel 20e through the first opening end portion 10a of the hollow fiber membrane sheet-like material 10 on the first end portion 13a side. Flow to the first end 13a side of the treated water that has blocked the flow to the side and has flowed into the first catchment channel 20e through the first opening end 10a of the hollow fiber membrane sheet-like material 10 on the second end 13b side. Block. The second closing portion 38 is a flow of the treated water flowing into the second catchment channel 20f through the second opening end portion 10b of the hollow fiber membrane sheet-like material 10 on the first end portion 15a side to the second end portion 15b side. Is blocked, and the flow of the treated water flowing into the second catchment channel 20f through the second opening end portion 10b of the hollow fiber membrane sheet-like material 10 on the second end portion 15b side is blocked to the first end portion 15a side.

In such an embodiment, as shown in FIG. 6, the first water collecting channel of the first water collecting pipe 12 below the lower portion of each hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10 on the first end portion 13a side. The treated water collected in 20e is sent to the first end portion 15a of the upper second water collecting pipe 14 through the first tubular column 16 and is taken out from the take-out port 40a. Further, the treated water collected in the second water collecting channel 20f of the second water collecting pipe 14 above from the upper portion of each hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10 on the first end portion 13a side is the second collecting water. It is sent to the first end portion 15a of the water pipe 14 and taken out from the take-out port 40a.
Further, the treated water collected in the first water collecting channel 20e of the first water collecting pipe 12 below from the lower portion of each hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10 on the second end portion 13b side is the second. It is sent to the second end portion 15b of the upper second water collecting pipe 14 through the tubular support 18 and is taken out from the take-out port 40b. Further, the treated water collected in the second water collecting channel 20f of the second water collecting pipe 14 above from the upper portion of each hollow fiber membrane 11 of the hollow fiber membrane sheet-like material 10 on the second end portion 13b side is collected in the second collection. It is sent to the second end portion 15b of the water pipe 14 and taken out from the take-out port 40b. As a result, the hollow fiber membrane sheet-like material 10 can be efficiently used for processing as a whole.

The hollow fiber membrane element of the present invention is not limited to the hollow fiber membrane element 1 described above.
For example, the number and position of the outlets are not limited to the above-mentioned number and position, and can be set as appropriate.
The hollow fiber membrane element may be used in a state where the hollow fiber membrane elements of the hollow fiber membrane sheet-like material are arranged so that the length direction of each hollow fiber membrane is horizontal.

2. 2. Method for Manufacturing Hollow Fiber Membrane Element The method for manufacturing the hollow fiber membrane element of the present invention is not particularly limited. Hereinafter, as an example of the method for manufacturing the hollow fiber membrane element of the present invention, the method for manufacturing the hollow fiber membrane element 1 described above will be described.

Examples of the method for manufacturing the hollow fiber membrane element 1 include methods having the following steps (a) to (e).
Step (a): The first end portion and the second end portion of the plurality of hollow fiber membranes 11 bundled in a sheet shape are inserted into a potting case, and a potting resin is injected and cured to form a hollow fiber membrane sheet. Fix the object to the potting case.
Step (b): The tip of the potting case to which the hollow fiber membrane 11 is fixed is cut to obtain the hollow fiber membrane sheet-like material 10.
Step (c): The first tubular column 16 and the second tubular column 18 are connected to the protrusions of the first end portion 13a and the second end portion 13b of the first water collecting pipe 12.
Step (d): The first tubular column 16 and the second tubular column 18 are connected to the protrusions of the first end portion 15a and the second end portion 15b of the second water collecting pipe 14.
Step (e): The first opening end portion 10a of the hollow fiber membrane sheet-like material 10 is inserted into the first water collecting pipe 12 and fixed by the potting portion, and the second hollow fiber membrane sheet-like material 10 is inserted into the second water collecting pipe 14. The opening end portion 10b is inserted and fixed by the potting portion.
If necessary, a deformation suppressing member is provided in the water collecting pipe.

3. 3. Hollow fiber membrane module The hollow fiber membrane module of the present invention includes a plurality of hollow fiber membrane elements of the present invention. The hollow fiber membrane module of the present invention can adopt known embodiments except that the hollow fiber membrane module of the present invention includes a plurality of hollow fiber membrane elements of the present invention.
In the hollow fiber membrane module of the present invention, for example, a plurality of hollow fiber membrane elements are spaced apart from each other so that the surfaces of the hollow fiber membrane sheet-like material face each other and in a direction perpendicular to the surface of the hollow fiber membrane sheet-like material. Can be placed side by side with an open space. Further, a plurality of units in which a plurality of hollow fiber membrane elements are arranged in such a manner may be formed, and the plurality of units may be stacked one above the other.

4. Action Effect The hollow fiber membrane element of the present invention has excellent pressure resistance by setting the cross-sectional area of the catchment channel in the plane perpendicular to the longitudinal direction of the catchment pipe to 100 to 350 mm ² . Therefore, even if pressure is applied to the inside of the water collecting pipe during backwashing at high pressure, it is possible to prevent the water collecting pipe from being damaged and water leakage.
The use of the hollow fiber membrane element and the hollow fiber membrane module of the present invention is not particularly limited, and may be used for wastewater treatment, or may be used for producing purified water such as sterile water, drinking water, and high-grade pure water. The hollow fiber membrane element of the present invention has excellent pressure resistance that can withstand backwashing, and is therefore particularly useful for producing purified water.

5. Water treatment device The water treatment device of the present invention includes the hollow fiber membrane module of the present invention and an air diffuser arranged below the hollow fiber membrane module.
The air diffuser is not particularly limited, and a known air diffuser for cleaning the membrane can be used without limitation.
Examples of the water treatment apparatus of the present invention include an apparatus used in the membrane separation activated sludge (MBR) method and a water purification apparatus for treating river water and the like.

6. Water treatment method The water treatment method of the present invention is a method of water treatment using the water treatment apparatus of the present invention. The water treatment method of the present invention is not particularly limited, and examples thereof include a membrane separation activated sludge (MBR) method and water purification treatment of river water and the like.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following description.

[Example 1]
Hollow fiber membrane elements having the same shape as the hollow fiber membrane elements 1 illustrated in FIGS. 1 to 3 were produced.
The cross-sectional area b ₁ of the first catchment channel of the first catchment pipe and the cross-sectional area b ₂ of the second catchment channel of the second catchment pipe are 300 mm ² , respectively, and the height H of the first catchment channel and the second catchment channel is 18 mm, respectively. , The ratio a / b ₁ and the ratio a / b ₂ were 1.28, respectively.

[Example 2]
The forms of the first catchment pipe and the second catchment pipe are changed to the form having the deformation suppressing member exemplified in FIG. 3A, and the cross-sectional area, height H, ratio a / b ₁ and the cross-sectional area of the first catchment channel and the second catchment channel are changed. A hollow fiber membrane element having the same shape as that of Example 1 was produced except that the ratios a / b ₂ were changed as shown in Table 1.

[Example 3]
The forms of the first catchment pipe and the second catchment pipe are changed to the form having the deformation suppressing member exemplified in FIG. 3A, and the cross-sectional area, height H, ratio a / b ₁ and the cross-sectional area of the first catchment channel and the second catchment channel are changed. A hollow fiber membrane element having the same shape as that of Example 1 was produced except that the ratios a / b ₂ were changed as shown in Table 1.

[Comparative Example 1]
The forms of the first catchment pipe and the second catchment pipe are changed to the form having the deformation suppressing member exemplified in FIG. 3A, and the cross-sectional area and height H of the first catchment channel and the second catchment channel are shown without providing a support. A hollow fiber membrane element having the same shape as that of the first embodiment was produced except that the changes were made as shown in 1.

[Comparative Example 2]
Hollow fibers having the same shape as in Example 1 except that the cross-sectional areas, height H, ratio a / b ₁ and ratio a / b ₂ of the first catchment channel and the second catchment channel are changed as shown in Table 1. A membrane element was made.

[Withstand voltage test]
For the hollow fiber membrane elements of each example, each hollow fiber membrane was cut at the positions of the openings of the first water collecting pipe and the second water collecting pipe, and the cut portions were sealed with a potting resin. Then, water was supplied into each water collecting pipe, and the water pressure was gradually increased until the water collecting pipe was damaged and a water leak occurred. Table 1 shows the water pressure at the time of water leakage in the hollow fiber membrane element of each example.

As shown in Table 1, the hollow fiber membrane elements of Examples 1 to 3 in which the cross-sectional area of the water collecting pipe is in an appropriate range are the comparative example 1 in which the cross-sectional area of the water collecting pipe is small and the comparison in which the cross-sectional area of the water collecting pipe is large. Compared with the hollow fiber membrane element of Example 2, the water pressure at the time of water leakage was high and the pressure resistance was excellent. Further, the hollow fiber membrane elements of Examples 2 and 3 provided with the deformation suppressing member had further excellent pressure resistance as compared with the hollow fiber membrane element of Example 1 not provided with the deformation suppressing member.

1 ... Hollow fiber membrane element, 10 ... Hollow fiber membrane sheet-like material, ... 10a First opening end, 10b ... Second opening end, 11 ... Hollow fiber membrane, 12 ... First water collecting pipe (water collecting pipe), 13a ... 1st end, 13b ... 2nd end, 14 ... 2nd water collecting pipe (water collecting pipe), 15a ... 1st end, 15b ... 2nd end, 16 ... 1st tubular strut (post), 17a ... 1st end, 17b ... 2nd end, 18 ... 2nd tubular strut (post), 19a ... 1st end, 19b ... 2nd end, 20a ... side wall, 20b ... side wall, 20c ... bottom, 20d ... opening, 20e ... first collecting channel (collecting channel), 20f ... second collecting channel (collecting channel), 20 g ... step, 21 ... member, 21a ... deformation suppressing member, 22a ... potting part, 23 ... potting case , 23a ... potting part, 23b ... potting part, 23c ... interface, 24a ... tubular part, 24b ... protrusion, 24c ... peripheral wall part, 24d ... opening, 25 ... lid member, 26 ... tubular sleeve, 28 ... insertion part, 30 ... resin, 32 ... block, 33 ... protective layer, 34 ... block, 36 ... first closed portion, 38 ... second closed portion, 40a, 40b ... outlet, 61 ... water pipe.

Claims (14)

A hollow fiber membrane element having a hollow fiber membrane, a water collecting pipe, and an outlet for taking out treated water from the water collecting pipe.
The hollow fiber membrane and the water collecting pipe are fixed by a potting portion, and are fixed.
A water collecting channel having the potting portion and the water collecting pipe as a wall surface is provided inside the water collecting pipe.
The end of the hollow fiber membrane communicates with the water collecting pipe and
A hollow fiber membrane element having a cross-sectional area of 100 to 350 mm ² in any catchment channel cross section perpendicular to the longitudinal direction of the catchment pipe. The hollow fiber membrane element according to claim 1, wherein the length of the hollow fiber membrane in the cross section of the catchment channel in the longitudinal direction is 20 mm or less. The hollow fiber membrane element according to claim 1 or 2, which has at least one of a deformation suppressing member in contact with the wall of the water collecting pipe and a deformation suppressing member integrated with the water collecting pipe. The hollow fiber membrane element according to claim 3, wherein the deformation suppressing member is a rib. The hollow fiber membrane element according to any one of claims 1 to 4, wherein the water collecting pipe has a step, and the step and the lower portion of the potting portion are adhered to each other. The hollow fiber membrane element according to claim 5, wherein the step is 0.5 mm or more. The water collecting pipe is composed of a first water collecting pipe and a second water collecting pipe.
The second water collecting pipe is located on the opposite side of the first water collecting pipe and the hollow fiber membrane in the longitudinal direction, and the first water collecting pipe and the second water collecting pipe are connected by a support.
The hollow fiber membrane element according to any one of claims 1 to 6. The hollow fiber membrane element according to claim 7, wherein the water passage inside the column, the first water pipe of the first water pipe, and the second water pipe of the second water pipe communicate with each other. Let b be the cross-sectional area on an arbitrary surface perpendicular to the longitudinal direction of the water collecting channel of the water collecting pipe, and let a be the cross-sectional area on an arbitrary surface perpendicular to the longitudinal direction of the water passage of the column. The hollow fiber membrane element according to claim 8, which satisfies the relationship of b. The hollow fiber membrane element according to claim 9, which satisfies the following formulas (1) and (2).
a / b ₁ ≧ 0.9 ・ ・ ・ (1)
a / b ₂ ≧ 0.9 ・ ・ ・ (2)
a: Arbitrary cross-sectional area of the drainage channel of the column b ₁ : Cross-sectional area in any surface perpendicular to the longitudinal direction of the first catchment channel of the first catchment pipe b ₂ : Longitudinal direction of the second catchment channel of the second catchment pipe Cross-sectional area on any surface perpendicular to The hollow fiber membrane element according to claim 9 or 10, which satisfies the following formulas (3) and (4).
0.5 × a ≦ b ₁ ... (3)
0.5 × a ≦ b ₂ ... (4)
a: Arbitrary cross-sectional area of the drainage channel of the column b ₁ : Cross-sectional area in any surface perpendicular to the longitudinal direction of the first catchment channel of the first catchment pipe b ₂ : Longitudinal direction of the second catchment channel of the second catchment pipe Cross-sectional area on any surface perpendicular to A hollow fiber membrane module comprising a plurality of hollow fiber membrane elements according to any one of claims 1 to 11. A water treatment device comprising the hollow fiber membrane module according to claim 12 and an air diffuser arranged below the hollow fiber membrane module. A water treatment method using the water treatment apparatus according to claim 13.

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