JPH05261253A - Hollow fiber membrane module - Google Patents

Abstract

PURPOSE:To provide a hollow fiber membrane module contg. hollow fiber membranes which are hardly integrated by sticking even when used to filter highly polluted water and capable of easily and efficiently restoring filtering function reduced by use. CONSTITUTION:Both ends of each hollow fiber membrane 3 are fixed with fixing members 2 in two housings 1 while keeping the opening state. The interval between both the housings 1 is variable. The shape of sections of the fixing members 2 perpendicular to the hollow fiber membrane 3 is made slender and nearly rectangular.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber membrane module, and more particularly to a hollow fiber membrane module suitable for filtering a highly polluted liquid (particularly organic matter pollutant).

[0002]

2. Description of the Related Art Conventionally, hollow fiber membrane modules have been manufactured using sterile water,
It has been widely used in the field of so-called microfiltration such as the production of drinking water and high-purity water, and the purification of air, but in recent years it has been highly polluted such as secondary and tertiary treatment in sewage treatment plants and solid-liquid separation in septic tanks. Various types of studies have been conducted for use in water treatment.

However, the hollow fiber membrane modules used in these fields are also of the cylindrical type in which the hollow fiber membranes are arranged concentrically in a circular shape or concentric circle, which has been used in the field of conventional microfiltration. Was the most. Further, even if improvements are made, most of them merely change the filling rate or filling form of the hollow fiber membrane.

[0004]

However, when a highly polluted water (for example, SS ≧ 50 ppm, TOC ≧ 100 ppm) is filtered using such a conventional hollow fiber membrane module, it is not suitable for use. Through the deposits such as organic substances attached to the surface of the hollow fiber membranes, the hollow fiber membranes are fixed (adhered) and integrated with each other, thereby reducing the effective membrane area of the hollow fiber membranes in the module. A sharp decrease in filtration flow rate was observed. In particular, this phenomenon was remarkable in the hollow fiber membrane in the central part of the cylindrical module, and was more remarkable in the large-sized one.

Further, even when the hollow fiber membrane module in which the hollow fiber membranes are fixed and integrated as described above is regularly subjected to membrane surface cleaning or backwashing, it is easy to recover the function of the module once fixed and integrated. However, there was a decrease in cleaning efficiency.

The object of the present invention is to make it difficult for the hollow fiber membranes in the module to be fixed and integrated even when used for filtering highly polluted water, and to easily and efficiently recover the filtration function which has been reduced by use. It is to provide a hollow fiber membrane module that can be well implemented.

[0007]

That is, the present invention provides a hollow fiber membrane module in which both ends of a hollow fiber membrane are fixed by fixing members in two different housings while maintaining their open states. In the hollow fiber membrane module, each of the members has a cross section that is perpendicular to the hollow fiber membrane and has an elongated rectangular shape, and the distance between the housings can be changed.

[0008]

The hollow fiber membrane module of the present invention will be described in more detail below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the hollow fiber membrane module of the present invention, and FIG. 2 shows the same module.
It is a figure which shows the state which shortened the distance between housings.

The hollow fiber membrane module of the present invention basically comprises two housings 1, a fixing member 2, and a large number of hollow fiber membranes 3. In addition to these, movable column 4
Various accessory members such as the above may be attached.

The housing 1 has an elongated and substantially rectangular opening, in which a fixing member is filled and fixed together with a hollow fiber membrane and has a treated water outlet 5. The two housings 1 are basically arranged so that their openings are opposed to each other, but are configured so that the distance between the two housings can be changed. That is, a member such as the movable support column 4 shown in FIG. 1 may be provided, which defines a tentative positional relationship between the two housings but can freely adjust the distance between them. A structure in which the distance between the housings does not extend beyond the length of the hollow fiber membranes only by the flexible hollow fiber membranes disposed between the housings without disposing any member. May be done.

The housing 1 may be made of any material as long as it has mechanical strength and durability, and examples thereof include polycarbonate, polysulfone, polypropylene, acrylic resin, ABS resin, and modified PPE resin. When incineration is required after use, it is preferable to use a hydrocarbon resin that can be completely burned without producing toxic gas by burning.

The fixing member 2 fixed to the opening of the housing 1 fixes both ends of a large number of hollow fiber membranes 3 to the inside of the housing while maintaining the open state thereof, and at the same time, the hollow fiber membranes are filtered. In order to function as, it functions as a member that liquid-tightly separates the water to be treated from the treated water. The fixing member 2 is usually formed by curing a liquid resin such as epoxy resin, unsaturated polyester resin or polyurethane.

The fixing member 2 has a substantially rectangular shape whose cross section perpendicular to the hollow fiber membrane is elongated, and the length of the short side of this rectangular shape is preferably 30 mm or less, preferably 15 mm.
The following is particularly preferable. In this way, the fixing member has an elongated rectangular shape in cross section. In other words, by deploying the hollow fiber membranes in a sheet-like manner between the two housings and arranging them, the entire hollow fiber membrane bundle is integrated. It is possible to prevent the effective membrane area of the hollow fiber membrane from abruptly reducing by sticking and integrating it in the shape of a bar. Further, even if the hollow fiber membranes are fixed to each other, the fixed portion of the hollow fiber membranes is thin. Furthermore, by changing the distance between both housings, the hollow fiber membranes, which were arranged as a flat sheet when used as a filtration module, were able to freely adjust the tension of the hollow fiber membranes and physically fix the adhered state. It is also possible to separate it, and the recovery processing of its filtering function can be easily performed. The length of the long side of the rectangle is not particularly limited, but if it is too short, it is not preferable because the number of hollow fiber membranes that can be arranged in one hollow fiber membrane module decreases, while if it is too long, manufacturing is difficult. Is not desirable. Usually, the long side length is 100-
It is about 2000 mm.

As the hollow fiber membrane 3, various types can be used, for example, various types of materials such as cellulose type, polyolefin type, polyvinyl alcohol type, PMMA type and polysulfone type can be used. However, considering the ease of processing into a knitted fabric, a material having a high strength and elongation such as polyethylene is preferable. The pore diameter, porosity, film thickness, inner diameter, etc. are not particularly limited as long as they can be used as a filtration membrane.

The preferred length of the hollow fiber membrane disposed between the two housings varies depending on the hole diameter, the inner diameter, etc. of the hollow fiber membrane, but is usually about 10 to 2000 mm.

When manufacturing the hollow fiber membrane module of the present invention, in order to store the hollow fiber membrane 3 in the elongated rectangular opening of the housing 1, several hollow fiber membranes are used, for example, as wefts and knitted. It is preferable to use a laminated body in which one sheet is laminated. Although it is difficult to store the hollow fiber membrane stripped in the elongated rectangular opening, the knitted fabric can be stored easily. Further, when laminating the hollow fiber membrane knitted fabrics, hollow fiber membrane knitted fabrics having different performances can be used. For example, when a hollow fiber membrane module is produced by using a sandwich of sandwiches of a hydrophobic hollow fiber membrane knitted with a hydrophilically treated hollow fiber membrane knitted fabric, a hydrophobic hollow fiber membrane layer Can be used as a means for supplying bubbles during backwashing.

Instead of using a laminate of several knitted fabrics, a folded knitted fabric in which the knitted fabric of the hollow fiber membrane is folded in a zigzag shape (arranged in a meandering shape) may be used. If this storage method is adopted, it is possible to prevent uneven distribution of the hollow fiber membranes on the fixing member when the hollow fiber membranes have a relatively low packing density.

When the hollow fiber membrane module of the present invention is used, a so-called pressure filtration method in which the module is placed in a closed container and the water to be treated is pressed to permeate the hollow fiber membrane can be employed, but it is also active pollutant. It is preferable to arrange the hollow fiber membrane module in a tank or a sedimentation tank and use it in a suction filtration method in which the side for collecting the treated water that has permeated the hollow fiber filtration membrane is sucked. In particular, by adopting a so-called intermittent suction operation method in which suction is periodically stopped for a predetermined time, it is possible to efficiently prevent the membrane surface deposits from entering the internal pores, and the hollow fiber membrane module The frequency of function recovery processing can be reduced.

The flow of the water to be treated in the suction filtration method is made to flow almost perpendicularly to the fiber length direction of the hollow fiber membrane so as to enhance the contact with the hollow fiber membrane and improve the cleaning effect of the membrane surface. preferable.

Further, as one of the preferable usage methods suitable for the shape of the hollow fiber membrane module of the present invention, there is a method of arranging this module in a rotating body and carrying out filtration while rotating the module. As a method of attaching the module to the rotating body, for example, two housings of the module are arranged in a vertically extending manner in a horizontal direction with the rotating body as an axis, and the hollow fiber membrane extends vertically between the two housings. The aspect which arranges so that it may be mentioned.

The hollow fiber membrane module of the present invention is particularly suitable for filtration of highly polluted water. Specific fields of application include filtration of river water, industrial water filtration, solid-liquid separation of sewage, and wastewater treatment ( For example, processing in a combined septic tank) and the like.

As the method for recovering the function of the hollow fiber membrane module of the present invention, the backwashing method can be easily carried out as in the case of the ordinary module, but the distance between the two housings is shortened or changed. At the same time, for example, a method of physically cleaning the film surface with a sponge ball or the like or a method of cleaning with ultrasonic waves can be adopted as an efficient method suitable for the physical form of the module.

[0024]

EFFECTS OF THE INVENTION In the hollow fiber membrane module of the present invention, since more hollow fiber membranes come into direct contact with the water to be treated, the accumulation of organic substances between the hollow fiber membranes is suppressed and the hollow fiber membranes are fixedly integrated. It is possible to maintain high filtration efficiency for a long period of time especially in the filtration of highly polluted water. Further, since the distance between the housings can be changed, the filtering function recovery process by washing can be efficiently performed.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing the hollow fiber membrane module of FIG. 1 with the distance between the housings shortened.

[Explanation of symbols]

 1 Housing 2 Fixing Member 3 Hollow Fiber Membrane 4 Movable Post 5 Treated Water Outlet

Claims (1)

[Claims] 1. A hollow fiber membrane module in which both ends of a hollow fiber membrane are fixed by fixing members in two different housings while maintaining open states, and a cross section perpendicular to the hollow fiber membrane of the fixing member. The hollow fiber membrane module has a substantially elongated rectangular shape and is configured so that the distance between both housings can be changed.