JP2920336B2 - Flat hollow fiber membrane module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-shaped flat hollow fiber membrane module used for liquid filters in various fields such as industrial water purifiers.

[0002]

2. Description of the Related Art In general, a liquid filter such as a water purifier or the like is configured such that one end or both ends of a hollow fiber membrane are focused, and the focused end is fixed with a resin while maintaining the opening of the hollow fiber membrane to form a liquid between the inner wall of the container and the liquid. Raw water is filtered through the hollow fiber membrane wall. As the filtration direction, there are an external pressure type in which raw water passes from the outside to the inside of the hollow fiber membrane and an internal pressure type in which raw water passes from the inside to the outside of the hollow fiber membrane. It is used in a wide range of applications, including purification, purification of domestic wastewater from industrial wastewater such as sewage, and furthermore, in the field of water treatment and industrial process filtration such as liquor filtration and dye filtration.

In particular, in recent years, there has been a strong interest in the treatment of industrial water from the viewpoints of environmental protection and sanitation, and as an effective purification means for industrial water, such as removal of organic substances and inorganic substances such as heavy metals in sewage and wastewater. The use of liquid filters using porous hollow fiber membranes is increasing.

[0004] Unlike the case of purification of tap water such as tap water, such an industrial liquid filter has a large clogging of the hollow fiber membrane at the time of the filtration treatment.
The air is sent to vibrate the hollow fiber membrane to wash the membrane surface, and the membrane surface is washed repeatedly by passing treated water in the opposite direction of the filtration process.

[0005]

In the case of a general industrial liquid filter, the number of hollow fibers per unit area is increased and the hollow fibers are densely bundled in order to make the filtration module compact and increase the filtration efficiency. The membrane area is increased to make it difficult for air and water to pass through when cleaning the membrane surface.Thus, the washing is not performed sufficiently, and the filtration efficiency gradually decreases.
This is a cause of shortening the life of the module.

As a solution to this problem, there has been proposed a flat type module in which hollow fiber membranes are arranged in a sheet form, instead of a focusing type filtering module. (Tokuhei 4-26885
No.)

[0007] In such a sheet-shaped flat hollow fiber type module, the hollow fiber membranes can be arranged evenly between the inner and outer layers with a space between the layers. Since it is extremely easy to wash, it has begun to be used as a module suitable for industrial use, for example, it is possible to suppress a decrease in filtration efficiency as before.

However, in the hollow fiber membrane module, it is necessary to partition the hollow portion of the hollow fiber membrane from the outer surface in a liquid-tight manner so that the hollow fiber membrane can be permeated by the membrane wall. At the same time, the ends are fixed, and at the same time, they are integrally joined to the inner peripheral surface of the module case.At the time of this potting, the capillarity causes the bases of the individual hollow fibers constituting the hollow fiber membrane sheet to have " Penetration by the potting resin referred to as “creeping” occurs, and a hardened portion by the potting resin is generated in a width of about 10 to 20 mm from the potting surface.

Accordingly, when the hollow fiber membrane is vibrated by air bubbling (air bubbling) at the time of cleaning the membrane surface, the hollow fiber membrane is formed in a sheet shape. As a result, stress due to buckling of the hollow fiber membrane tends to concentrate on the interface of the hollow fiber membrane, resulting in a decrease in strength at the interface.As a result, cracks and cuts occur in the hollow fiber membrane at the interface between the cured resin portion and the hollow fiber membrane. Short-term use can cause module functionality to disappear.

In such a sheet-shaped flat module, the hollow fiber membranes located at the side ends of the hollow fiber membranes arranged in a sheet form are separated by vibrations or the like during potting. However, there are problems such as difficulty in forming a uniform module.

The present invention solves such a problem in an industrial liquid filter using a sheet-shaped flat hollow fiber membrane module. It is an object of the present invention to provide a sheet-shaped flat hollow fiber membrane module that does not cause damage to the hollow fiber membrane at the interface between parts.

[0012]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a sheet-like flat type in which one end is formed of a potting portion fixed by a potting resin and the other end is linearly restrained by a restraining thread. A hollow fiber membrane module,
In the sheet-like hollow fiber membrane constituting the intermediate portion of the hollow fiber membrane module, the individual hollow fiber membranes are arranged in parallel in a separated state, and the hollow fiber membranes arranged in parallel are in the vicinity of the potting portion, A sheet-shaped flat hollow fiber membrane module having a band-shaped restraining portion formed by a plurality of rows of restraining threads arranged in parallel with a potting portion.

[0013]

[Function] Since a plurality of restraining yarns are arranged in a belt shape,
During potting, the rise of the potting resin is blocked in a stepwise manner, and the rising resin adheres gradually from the potting part side to the hollow fiber membrane side, and the side close to the potting part is hard and close to the hollow fiber membrane The side has a soft and flexible structure. Therefore, stress caused by shaking of the hollow fiber membrane during cleaning of the hollow fiber membrane during clogging is not concentrated on a specific portion such as an interface between the crawling portion and the hollow fiber membrane, and the stress is dispersed throughout the belt-shaped portion. Take it.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view showing an example of a sheet-shaped flat hollow fiber membrane module of the present invention, and FIG. 2 is a partially enlarged view of the band-shaped restraining portion. 1 is a hollow fiber membrane, 2 is a restraining thread at the end of the sheet, 3 is a belt-like restraining section, 4, 5 and 6 are individual restraining threads constituting a belt-like restraining section, 7 is a potting section, and 8 is potting. The crawling portions made of resin are shown.

The sheet-shaped flat hollow fiber membrane module of the present invention uses a potting resin in a state where the hollow fiber membrane formed in a sheet shape keeps one end of each hollow fiber membrane 1 open. Fixed. Then, the potting resin is hardened while crawling up from the potting surface and reaching the belt-shaped restraining portion 3. In the belt-shaped restraining portion 3, the restraining thread 4 to the restraining thread 5, The amount of the resin adhered to the restraining thread 6 gradually decreases, and the hollow fiber membrane 1 and the swelling hardened portion 8 formed by the potting resin are connected in a flexible structure.

In FIG. 1, as the hollow fiber membrane 1, any generally used porous hollow fiber membrane such as a cellulose type, a polyolefin type, a polyvinyl alcohol type, a polysulfone type, and a PMMA type can be used.

The constraining thread 2 is a sheet-shaped hollow fiber membrane module at the extreme end of a sheet-shaped flat hollow fiber membrane module, the hollow fiber membranes 1 constituting a sheet being fixed to each other.
Generally, it is used as a warp at the time of forming a sheet-like hollow fiber membrane, and the hollow fiber membranes 1 are continuously bound to each other in a chain knitting shape. The restraining thread at one end is cut and removed to form an open end at the end when the module is formed. As a kind of the fiber constituting the restraining yarn 2, a multifilament yarn or a spun yarn made of synthetic fiber having water resistance such as polyester fiber is used.

The flat hollow fiber membrane module in the form of a sheet according to the present invention has a fixed width from the potting portion 7 in addition to the constrained yarn 2 that linearly constrains the outermost end of the hollow fiber membrane 1. The band-shaped restraining portion 3 in which the restraining threads 4, 5, and 6 are arranged in a belt shape is provided substantially parallel to the potting portion 7 at the set position.

Although the band-shaped restraining portion 3 is composed of three in FIG. 1, the band-shaped restraining portion 3 is formed from the viewpoint of gradually increasing the swelling of the resin and increasing the stress relaxation at the time of cleaning as described above. It is preferable that the number of yarns constituting No. 3 increases as the effect increases.

For each of the constrained filaments 4, 5, and 6 constituting the band-shaped constrained portion 3, the band-shaped constrained portion 3 may be formed by simultaneously using a plurality of warps at the time of sheet formation. The constraint does not necessarily have to be a chain knitting shape, and may be continuously restricted in any form. As in the case of the constraining yarn 2, the type of the fibers of the constraining yarns 4, 5, and 6 constituting the belt-shaped constraining portion 3 is a multifilament yarn or a spun yarn made of water-resistant synthetic fiber such as polyester fiber. Can be used.

FIG. 2 is a partially enlarged view of the band-shaped restraining portion 3 (the resin does not move up). FIG. 2 shows a state in which the hollow fiber membrane 1 is restrained in a chain knit shape by the restraining yarns 4 and 5. FIG. 2 shows a model in which one hollow fiber membrane 1 is constrained in a chain knitting manner, but a plurality of hollow fiber membranes 1 may of course be bundled.

Since the band-shaped restraining portion 3 has an uneven portion on the surface of the hollow fiber membrane, when it is used as a hollow fiber membrane module, dirt easily adheres to the module, and therefore, germs are easily propagated. It is preferable that the band-shaped restraining portion 3 has antibacterial properties from the viewpoint of preventing the occurrence of the squeezing.

As a means for imparting antibacterial properties to the band-shaped constraining section 3, antibacterial fibers may be used for a part or all of the yarns constituting the band-shaped constraining section 3. The fiber itself may have an antibacterial property, such as sometimes containing an antibacterial agent, or the manufactured synthetic fiber or the like may be coated or impregnated with the antibacterial agent. Examples of the antibacterial agent include an antibacterial zeolite carrying silver, a metal phthalocyanine compound, a quaternary nitrogen compound, and a copper compound.

The band-shaped restraining portion 4 is formed to have a certain width from the potting portion 7 of the sheet-shaped flat hollow fiber membrane module. The position of the band-shaped restraining thread 3 is preferably located at the upper end of the crawling-up portion 8 of the potting resin generated at the time of potting at the time of forming the module using the sheet-like hollow fiber membrane. Generally, the rise of the resin from the potting surface is about 10 to 20 mm. Therefore, it is preferable that the band-shaped restraining section 3 is positioned about 10 to 20 mm above the potting section 7. If the band-shaped restraining portion 3 largely deviates from the upper end portion of the crawling portion 8, the stress due to the vibration of the hollow fiber membrane 1 cannot be dispersed and absorbed, and the interface between the hollow fiber membrane 1 and the crawling portion 8 is formed. This is undesirable because the module tends to concentrate and damage the module.

The sheet-like hollow fiber membrane used in the sheet-like flat hollow fiber membrane module of the present invention may be produced by any method, for example, Japanese Patent Publication No. 4-26886.
It is easy to use the devices and methods described in Japanese Patent Application Laid-Open No. 63-91673 and Japanese Patent Application Laid-Open No. 63-91673. The flat hollow fiber membrane module in the form of a sheet can be formed by a method similar to or similar to a general flat hollow fiber membrane module.

When the module is formed, the sheet-like hollow fiber membrane of the present invention can be formed into a module by converging it into a spiral shape or a cylindrical shape in addition to the flat type shown in the figure. It is possible to prevent a decrease in the strength of the interface due to climbing.

[0028]

According to the sheet-shaped flat hollow fiber membrane module of the present invention, the interface between the hardened portion and the hollow fiber membrane caused by the rise of the potting resin is grasped in a flexible structure by the band-shaped restraining threads. Therefore, stress due to vibration or the like at the time of cleaning the hollow fiber membrane can be dispersed and absorbed, and the hollow fiber membrane is not damaged. In addition, since one end is also linearly constrained by the constraining thread, the disturbance of the hollow fiber membrane during washing is reduced. As described above, the flat hollow fiber membrane module of the present invention is easy to clean when clogged, and is extremely suitable for an industrial liquid filter module such that the damage to the hollow fiber membrane is extremely small.

Further, if a thread having an antibacterial property is used for the band-shaped restraining portion, it is possible to prevent the propagation of various bacteria when used as a module.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a sheet-shaped flat hollow fiber membrane module of the present invention.

FIG. 2 is a partially enlarged view of a band-shaped constrained portion of the sheet-shaped flat hollow fiber membrane module of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow fiber membrane 2 Restricted thread at the end of the sheet 3 Band-shaped constrained part 4 Individual constrained thread forming a band-shaped constrained part 5 Individual constrained thread forming a band-shaped constrained part 6 Band-constrained part The individual restraining yarns that make up 7 Potting section 8 Crawling section

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Watari 4-160 Sunadabashi, Higashi-ku, Nagoya City, Aichi Prefecture Mitsubishi Rayon Co., Ltd. Product Development Research Center (72) Inventor Masaaki Sato 4-1-1 Sunadabashi, Higashi-ku, Nagoya City, Aichi Prefecture No. 60 Investigator, Mitsubishi Rayon Co., Ltd. Product Development Laboratory Junko Yoshimizu (56) References JP-A-6-114242 (JP, A) JP-A-62-57965 (JP, A) (58) Fields investigated (Int .Cl. ⁶ , DB name) B01D 63/02 B01D 63/00 500 B01D 65/02 500 C02F 1/44

Claims (2)

(57) [Claims] 1. A sheet-shaped flat hollow fiber membrane module having a potting portion fixed at one end with a potting resin and having an opposite end portion linearly restrained by a restraining thread. In the sheet-like hollow fiber membrane constituting the intermediate portion of the fiber membrane module, individual hollow fiber membranes are arranged in parallel in a separated state, and the hollow fiber membranes arranged in parallel are arranged in a potting section near the potting section. A flat hollow fiber membrane module in the form of a sheet, comprising a band-shaped restraining portion formed by a plurality of rows of restraining threads arranged in parallel with the sheet. 2. The sheet-shaped flat hollow fiber membrane module according to claim 1, wherein the restraining thread forming the belt-like restraining portion has antibacterial properties.