JP2620254B2 - Hollow fiber membrane filtration module - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hollow fiber membrane filtration module for liquid filtration, and more particularly, to treatment of a large amount of water containing suspended substances and removal of suspended substances in air. The present invention relates to a hollow fiber membrane filtration module that is suitable for use as a filter.

[Conventional technology]

BACKGROUND ART Hollow fiber filtration membranes have been widely used for various purposes such as production of high-purity industrial water and gas filtration, since they have an excellent filtration function.

Hollow fiber membrane filtration modules in which such hollow fiber filtration membranes are modularized include two types: one that filters the hollow fiber from the hollow part to the outside and one that filters the hollow fiber from the outside to the hollow part. There are different types. However, in the former type of module, the passage resistance of the fluid to be treated inside the hollow fiber is large, and when a suspended substance remains in the hollow portion of the hollow fiber and causes clogging, the filtration function of the hollow fiber is reduced. Due to the difficulty of the recovery treatment, the latter type has been often used when there are many suspended substances contained in the fluid to be treated.

[Problems to be solved by the invention]

Most of these conventional modules have hollow fibers housed in a straight pipe, and the inlet and outlet of the fluid to be treated are provided on the side of the straight pipe. Therefore, when a plurality of modules are connected in series and used, it is necessary to adopt a connection method in which the flow of the fluid to be treated is bent in a complicated manner, the pressure loss of the fluid to be treated is large, and an excessive pumping capacity is required. There are disadvantages, such as the need for them, the restriction on the number of connections, and the large energy loss.

Further, when a relatively large amount of fluid is industrially processed, the dimensions of the hollow fiber membrane filtration module must be increased. In particular, in order to solve the above problem, the hollow fiber membrane filtration module uses a straight pipe having both ends opened as both ends of the fluid to be treated, and one end is coaxial with the straight pipe in a central portion inside the straight pipe. And a curved pipe whose other end is located outside of the straight pipe is provided.
When the module is configured as a module having a structure in which the hollow fibers bundled in the shape of a letter are fixed, as the size increases, the outer peripheral portion of the hollow fiber bundle is effectively used, but the utilization efficiency of the central portion of the hollow fiber bundle is reduced. There is a problem that the recovery flow rate of the filtered liquid decreases significantly with time.

An object of the present invention is to provide a hollow fiber membrane filtration module which solves the above-mentioned problems and is particularly suitable for industrial fluid treatment.

[Means for solving the problem]

That is, the gist of the present invention resides in that a straight pipe (1) and one end thereof are arranged coaxially with the straight pipe at a radially central portion inside the straight pipe, and the other end is located outside the straight pipe. Curved pipe (2)
A hollow fiber membrane bundle (3) bundled in a U-shape or a hollow fiber membrane (3) bundle with one end kept open and the other end closed; a round bar (6); an open end of the hollow fiber membrane bundle And a potting material (5) for fixing the round bar and fixing the opening end of the hollow fiber membrane bundle of the potting material in a straight pipe in a liquid-tight manner at the curved pipe end. The round bar is arranged coaxially with the straight pipe, and the hollow fiber membrane bundle is in a hollow fiber membrane filtration module arranged around the round bar.

[Preferred embodiment for carrying out the invention]

Hereinafter, the hollow fiber membrane filtration module of the present invention will be described in detail with reference to the drawings.

FIG. 1 and FIG. 2 are schematic cross-sectional views each showing one embodiment of the hollow fiber membrane filtration module of the present invention, and FIG. 3 is a view showing a flange portion of a straight pipe with a flange.

The straight pipe 1 may have the same diameter throughout, or may be connected to a different diameter in the middle as shown in the figure. One end of the curved tube 2 is located at the center of the straight tube 1 and is arranged coaxially with the straight tube 1. The other end of the curved tube 2 is out of the straight tube 1, and the hollow fiber filtration is performed. It is the outlet for the purification fluid coming out through the membrane. In FIG.
Although an example of bending is shown at ゜, the angle is not necessarily 90 °, and the other end of the curved tube 2 may be at any angle as long as it goes out of the straight tube 1. The diameter of the curved tube 2 may be the same for the entire curved tube, or may be different for different portions as shown in FIG.

Preferably, the curved tube 2 is firmly fixed to the straight tube 1. In FIG. 1, a part of the straight pipe 1 is a straight pipe with a flange having a sectional shape as shown in FIG. 3, and is composed of a plurality of straight pipes joined at the flange part. Although an example of fixing with a flange is shown, the method of fixing the curved tube 2 is not limited to this.

The flange 4 shown in FIG. 3 has a space at the center corresponding to the inner diameter of the curved pipe, and the fluid to be processed flows freely in the straight pipe outside the curved pipe and inside the straight pipe. As many channels as possible are provided. In addition, the inner diameter of the straight pipe may be partially narrower than the others within a range where the pressure loss is not so large in order to hold the hollow fiber and increase the flow velocity locally.

The hollow fiber filtration membrane 3 is a hollow fiber bundle bundled in a U-shape, or one end of the hollow fiber bundle is kept open while the other end is closed, and the open end is kept open. As it is, it is fixed by a potting material 5 such as polyurethane, epoxy resin, unsaturated polyester resin, silicon resin or the like. Therefore, the effective membrane portion of the hollow fiber filtration membrane 3 is in the straight pipe.

The hollow fiber filtration membrane 3 is preferably one having flexibility. Examples of such hollow fibers are those for ultrafiltration or microfiltration made of materials such as polyolefin, fluorinated polyolefin, polysulfone, and polyacrylonitrile. The hollow fiber membrane can be raised.

The potting material 5 for fixing the hollow fiber bundle is fixed so that the surface fixing the open end of the hollow fiber is liquid-tight with the curved tube 2. The potting material 5 may be directly fixed to the end of the curved pipe, or a fixing member (flange) as shown in the figure.
The potting material 5 and the curved tube 2 may be fixed in a liquid-tight manner by connecting the fixing member to the curved tube.

At the center of the hollow fiber bundle, a round bar 6 is provided so as to be coaxial with the straight tube 1, and the thickness of the hollow fiber bundle around the round bar (measured from the surface of the round bar in the radial direction of the straight tube). 10)
It is arranged to be ~ 25cm. The round bar 6 may be a hollow pipe or a solid pipe. If it is hollow, it is desirable that the end be sealed so that fluid does not enter the pipe.

This round bar 6 is arranged to prevent the hollow fiber bundle from becoming excessively thick and making it impossible to effectively utilize the central part thereof. In addition, it also has the effect of preventing damage and the like. When the thickness of the hollow fiber bundle is less than 10 cm, the effective membrane area per volume of the hollow fiber membrane decreases, which is not preferable. Conversely, if the thickness exceeds 25 cm, it becomes difficult to measure the effective use of the central portion of the hollow fiber bundle. In addition, without providing a round bar, the inner diameter of the straight pipe in the portion for storing the hollow fiber bundle is reduced correspondingly, the radius of the hollow fiber bundle is made the same as the thickness of the hollow fiber bundle of the present invention, and the same effect is obtained. Even if it is attempted, in this case, the number of hollow fibers to be stored is reduced, and only those having a low processing capacity can be obtained.

The round bar 6 may be a simple round bar, but preferably has projections 7 on the surface, and the projections 7 are preferably uniformly distributed over the entire surface of the round bar. An example of the projection 7 is a small round bar embedded in the surface of the round bar 6 as shown in FIG. As a result, the flow of the fluid can be excessively disturbed in the hollow fiber bundle, and the efficiency of treating the fluid is improved.

The end of the round bar 6 is fixed together with the hollow fiber bundle by a potting material. In addition, the round bar 5 may be firmly fixed to a portion of the flange 4 protruding into the straight pipe or an inner wall of the straight pipe by an auxiliary tool or the like. In this way, the risk of damage to the potting portion when a force is applied to the round bar can be reduced. The hollow fibers may be evenly distributed around the round bar at the potting portion and fixed.However, it is necessary to divide the bundle into a plurality of hollow fiber bundles and pot them with the bundles uniformly arranged around the round bar. Can also. This is preferable because the fluid can more easily enter the hollow fiber bundle layer.

In the hollow fiber filtration module of the present invention, the fluid to be treated is introduced from one end a of the straight pipe, and the filtered fluid filtered by the hollow fiber filtration membrane passes through the inside of the hollow fiber and is taken out from one end c of the curved pipe. On the other hand, the unfiltered fluid is discharged from the other end b of the straight pipe. Therefore, the characteristic that the pressure loss is small because the filtered fluid to be processed flows substantially linearly in the straight pipe is exhibited.

The hollow fiber filtration module of the present invention is used for filtration of various types of water such as drinking water, industrial water, medical water, ultrapure water, and pyrogen-free water, polishing wastewater, oil-containing wastewater, coagulation treatment water, chelation reaction treatment water, and biological treatment water. It can be suitably used for filtration of turbid water, metal-containing powder wastewater, degreasing solution, filtration of SS-containing solvent, etc., filtration of valuable metal powders such as gold and silver, and filtration of flocs, and collection of valuable liquids in the food and pharmaceutical industries. .

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1. A polyethylene porous hollow fiber (polyethylene hollow fiber, EHF-390C, trade name) was placed in a straight pipe of 748 mm in length (length of a portion having an inner diameter of 68 mmφ of 700 mm and length of an inner diameter of 126 mmφ of 48 mm). (Mitsubishi Rayon Co., Ltd.)
Fig. 1 shows a polyurethane potting material with an outer diameter of 60mmφ, which is bundled in the shape of a letter and solidified by placing a round bar with a length of 763mm and an outer diameter of 32mmφ at the center, in a liquid-tight manner at the end of the curved pipe. Hollow fiber filtration module as shown (total membrane area: 5.58m
² ) was prepared.

A methane fermentation treatment liquid (MLSS 1,500mg /) of simulated wastewater (sugar water) was treated as wastewater to be treated in a wastewater treatment system configured with one module, and the flow rate in the straight pipe of the module was 1.0m / sec. flow so that the water to be treated inlet pressure 1.6Kg / cm ² G, was operated under the conditions of purified water outlet pressure 0.15Kg / cm ² G.

The recovery flow rate after the start of operation was 63 / m ² · hr after 1 minute, decreased to 37 / m ² · hr after 30 minutes, and 32 / m ² · hr after 1 hour.
Although reduced to m ² · hr, both the absolute value and the maintenance rate of the recovery flow rate were good, and it was confirmed that membrane filtration by the entire hollow fiber bundle was effectively performed.

Example 2. Exactly 32 mm in outer diameter of the same module as used in Example 1.
A cylindrical protrusion with an outer diameter of 10mmφ and a length of 10mm on the surface of a φ round bar
A module as shown in FIG. 2 constituted by uniformly distributing 30 pieces was produced. In a wastewater treatment apparatus having exactly the same configuration as that used in Example 1 for this module, the treatment of the methane fermentation treatment liquid was performed under exactly the same conditions as in Example 1.

As a result, the recovery flow rate after the start of operation was 71 / m 1 minute later.
A ² · hr, dropped to the 47 / m ² · hr after 30 minutes, but decreased to 41 / m ² · hr after 1 hour, both absolute and retention of the recovery flow better, the hollow fiber bundle It was confirmed that the entire membrane filtration was effectively performed.

Comparative Example 1. Without a round bar, 10,688 polyethylene hollow fibers (polyethylene hollow fiber, EHF-390C, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) were added to a potting material with a length of about 700 mm.
A hollow fiber filtration module (total membrane area: 9 m ² ) was produced in exactly the same manner as in Example 1 except that the module was fixed in a U-shape. This module was treated with a methane fermentation treatment solution under the exactly same conditions as in Example 1 in a wastewater treatment apparatus having exactly the same configuration as that used in Example 1.

In this case, the recovery flow rate after the start of operation is 53 minutes after one minute.
/ m is ² · hr, after 30 minutes decreased to 23 / m ² · hr,
After 1 hour, it decreased to 21 / m ² · hr.

(Effect of the present invention)

As described above, the hollow fiber filtration module of the present invention has a simple structure, is easy to assemble, can be easily connected to each other, has low passage resistance for the fluid to be treated, and has a hollow fiber inside the module. It has the feature that the flow rate maintenance rate of the filtration fluid is large because the whole is used effectively. Also, in such a fluid filtration system using a plurality of modules of the present invention connected to each other, the modules can be easily connected, the pressure loss is extremely small as compared with the conventional module, and the filtered and separated substances can be recovered. It is easy to use, and if an appropriate connecting member is used, an excellent effect of compact installation in a narrow place can be exhibited.

[Brief description of the drawings]

1 and 2 are schematic cross-sectional views each showing an example of an embodiment of the hollow fiber filtration module of the present invention, and FIG. 3 is a view showing a flange portion of a straight pipe with a flange. 1: Straight pipe, 2: Curved pipe 3: Hollow fiber filtration membrane, 4: Flange 5: Potting material, 6: Round bar 7: Projection a: Target fluid inlet, b: Target fluid outlet c: Filtration fluid outlet

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masujiro Arita 2-3-19 Kyobashi, Chuo-ku, Tokyo Inside Mitsubishi Rayon Engineering Co., Ltd. (56) References JP-A-62-132503 (JP, A)

Claims (4)

(57) [Claims] 1. A straight pipe (1), a curved pipe having one end arranged coaxially with the straight pipe at a radially central portion inside the straight pipe and the other end located outside the straight pipe. 2), a bundle of hollow fiber membranes (3) bundled in a U-shape or a bundle of hollow fiber membranes (3) with one end kept open, the other end closed, a round bar (6), and a hollow fiber membrane bundle A potting material (5) for focusing and fixing the open end and fixing the round bar, wherein the surface fixing the open end of the hollow fiber membrane bundle of the potting material is liquid-tight to the curved pipe end in the straight pipe. , A round bar is arranged coaxially with the straight pipe, and a hollow fiber membrane bundle is arranged around the round bar. 2. The hollow fiber membrane filtration module according to claim 1, wherein the thickness of the bundle of hollow fiber membranes (3) disposed around the round bar is 10 to 25 cm. 3. A round bar (6) having a plurality of projections (7) on its surface.
The hollow fiber membrane filtration module according to claim 1, comprising: 4. The hollow fiber membrane filtration module according to claim 3, wherein the projection (7) is a rod-shaped projection.