JPH11333262A - Assembled hollow fiber membrane module container and its cleaning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable retention of high membrane performance and make it possible to treat a large amount of a solution containing a high concentration of a turbid substance by mounting in a single container a plurality of external pressure hollow fiber membrane modules each having one end of a hollow fiber membrane fixed and another end thereof set free in such a manner that the free end is arranged upward vertically. SOLUTION: A module container 80 is installed in such a manner that a raw water inlet 86 is oriented downward vertically and an air vent 88 is oriented upward. Raw water is allowed to flow downward along a hollow fiber membrane in a module 81 through the raw water inlet 86, and is filtered. Then, refined permeation water is introduced into a permeation chamber of the module 81 and is extracted from an outlet 90 through an extraction pipe 72 and a joining pipe 87. The module 81 is constituted of a cylinder 83 penetrating a flat plate 82 secured to an opened end face of a main body 13 and a header 85 connected to a seat 84 jointed with the cylinder 83, and the follow fiber membrane is included within the cylinder 83 in a state wherein a free end thereof is oriented upward. Thus, adhesion of a solid matter onto the hollow fiber membrane is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly type hollow fiber membrane module container for separating a liquid containing turbidity into turbidity and fresh water, and a method for cleaning the same. In particular, it can be suitably used for treating a liquid containing a high-concentration turbid substance.

[0002]

2. Description of the Related Art Separation membranes have been recently used to separate solid and soluble substances from raw water in the process of producing pure water or water, in the production of foods and pharmaceuticals, and in the wastewater treatment of domestic and industrial wastewater. Many modules are used.

[0003] Separation membrane modules include hollow fiber membranes, tubular membranes,
It consists of a separation membrane such as a flat membrane and a cylinder filled with a large number of separation membranes. Among them, the hollow fiber membrane module has excellent characteristics that the packing density of the membrane is high and the membrane area can be increased. On the other hand, when the raw water contains a high-concentration solid substance, the hollow fiber membrane module tends to block the solid substance in the bundle of the hollow fiber membrane (external pressure type) or the hollow (internal pressure type). In the structure where the upper end is fixed and the lower end is free (one-end free type), the outer surface of the hollow fiber membrane becomes a filtration surface while giving a constant flow rate along the membrane surface from the fixed end side. Innovative measures such as supplying raw water (external pressure type) were used.

FIG. 4 shows an example of the structure of a conventional hollow fiber membrane module of an external pressure one end free type. Hollow fiber membrane module 10
No. 0 includes a cylinder 110 and a header 150 connected to one end thereof to isolate raw water and permeated water. Cylinder 110
The other end is provided with a non-permeated water outlet 160. The hollow fiber membrane 120 is fixed to the end of the cylinder 110 on the header 150 side together with the resin injection by a resin partition 130. The fixed end of the hollow fiber membrane 120 is open, but the other end is closed and in a free state. Raw water supply ports 140 are provided in the resin partition wall 130 at equal intervals in the radial direction.
The header 150 has a raw water inlet 15 at the axial center of its body.
1. A permeated water outlet 152 is provided on the side surface, and a partition 153 connected to the partition 130 is mounted separately from the main body. The partition 153 integrally has a raw water flow pipe 154 that communicates with the raw water supply port 140 in a liquid-tight manner. This partition 15
3, the header 150 is connected to the raw water chamber a communicating with the raw water inlet 151 and the permeated water chamber b communicating with the permeated water outlet 152.
And is divided into.

[0005] The hollow fiber membrane module 100 of the external pressure one end free type is installed with the raw water inlet 151 facing vertically upward and the non-permeated water outlet 160 facing downward. Then, the raw water is supplied to the raw water inlet 151, the raw water distribution pipe 154, and the raw water supply port 140.
, Flows along the outer surface of the hollow fiber membrane 120 toward the free end, and is filtered by the hollow fiber membrane 120 during that time. The permeated water purified in the hollow fiber membrane 120 by filtration enters the permeated water chamber b and is taken out from the permeated water outlet 152. On the other hand, the non-permeated water concentrated by filtration is discharged from the non-permeated water outlet 160.

[0006] The pollution of the environment is becoming serious year by year, and attention has been paid to the use of membrane separation technology as a countermeasure. Therefore, in order to meet this expectation with a hollow fiber membrane module having a small membrane area, use of a large number of hollow fiber membrane modules, enlargement of the module, assembly of a plurality of modules into one container, etc. Ingenuity is required.

However, using a large number of modules is inefficient in terms of space and cost. Increasing the size of the module itself has limitations in manufacturing and handling. Therefore, a collective hollow fiber membrane module container is generally used. As a conventional collective type hollow fiber membrane module container,
Japanese Patent Publication No. 6-79656 discloses a hollow fiber membrane having both ends fixed, and Japanese Patent No. 2708043.
It is known that one end is fixed and the other end is free, and the fixed end is vertically upward, as described in Japanese Patent Application Laid-Open No. H10-260,036.

[0008]

In an assembly type hollow fiber membrane module container, it is effective to flow raw water vertically upward in operation. However, in the above-mentioned conventional collective type hollow fiber membrane module container, since the upper end in the vertical direction is fixed not only to the both-end fixed type but also to the one-end free type, solid matter accumulates at the upper end and the membrane is formed. Performance had been reduced. Therefore, an object of the present invention is to provide a collective hollow fiber membrane module container capable of maintaining excellent membrane performance and a cleaning method for maintaining the same.

[0009]

In order to achieve the object, an assembly type hollow fiber membrane module container according to the present invention has an external pressure hollow fiber having a structure in which one end of a hollow fiber membrane is fixed and the other end is free. It is characterized in that a plurality of membrane modules are mounted in one container with their free ends facing vertically upward.

[0010] In this module container, the free end faces upward, so that solid matter is discharged from the non-permeated water outlet without remaining. Therefore, excellent film performance is maintained. If the hollow fiber membrane is accommodated in a rigid cylinder for each module, the hollow fiber membrane can be easily erected in the above direction.

Further, it is preferable that the cylinder has a through hole on a side surface near the fixed end of the hollow fiber membrane. This is because when air is blown from the fixed end of the hollow fiber membrane for cleaning, water and bubbles flowing in from the outside of the cylinder through the through hole can discharge solids. Therefore, in this method of cleaning the collective hollow fiber membrane module container, an appropriate method is to blow air into the cylinder from the fixed end side with the treatment liquid remaining inside and outside the cylinder.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a collective type hollow fiber membrane module container of the first embodiment, FIG. 2 is a longitudinal sectional view of a hollow fiber membrane module loaded in the container of FIG. 1, and FIG.
It is A sectional drawing.

The collective hollow fiber membrane module container 80 has a structure that can be divided into a main body 13 and a lid 14 for mounting or removing the hollow fiber membrane module 81. When used, it is installed upside down toward the drawing. However, in the following description of the structure, the upper side of the drawing is referred to as a head and the lower side is referred to as a bottom for convenience.

The main body 13 has a U-shaped cross section, a flat plate 82 is fixed to the opening end face in the radial direction, a drain port (non-permeated water outlet) 89 is provided on a side surface near the flat plate 82, and an air vent is formed in the center of the arc-shaped bottom. 88 are provided. The flat plate 82 is provided with a plurality of through holes at equal intervals in the radial direction, and a cylinder 83 made of a hard resin or the like is provided in each of the through holes.
And is fixed so as to be orthogonal to. A seat 84 having the same diameter as the cylinder 83 is connected to the head side of the cylinder 83, from which the hollow fiber membrane 2 of the module 81 is inserted and fixed by a V band (not shown) or the like. The lid 14 has a raw water inlet 86 at the center.

The hollow fiber membrane module 81 has a header 85 connected to the seat 84 for isolating raw water and permeated water. The fixed end located on the head side of the hollow fiber membrane 2 is open, but the other end located on the bottom side is closed and in a free state. The resin partition 3 is inserted into the seat 84, and the raw water supply ports 4 are provided in the resin partition 3 at equal intervals in the radial direction. The header 85 has a permeated water outlet pipe 7 on the side.
2 are connected to each other, and the respective outlet pipes 72 are joined to the water collecting pipe 87 so that permeated water can be extracted from the outlet 90 on the side surface of the lid 14. Further, a partition wall 53 connected to the partition wall 3 is mounted on the header 85. Partition wall 5
Reference numeral 3 integrally includes a raw water flow pipe 54 which communicates with the raw water supply port 4 in a liquid-tight manner. The partition 85 allows the header 85
Is separated into a raw water chamber a communicating with the raw water inlet 86 and a permeated water chamber b communicating with the permeated water outlet pipe 72.

As described above, when the module 81 alone is viewed, it is basically similar to the conventional product. However, in the conventional product shown in FIG. 4, the raw water inlet 151 and the non-permeated water outlet 160 are provided in the module 100, whereas in the embodiment of the present invention, they are provided in the lid 14 and the main body 13 respectively. 86 and a drain port 89 are provided.

This assembly type hollow fiber membrane module container 80
Is installed with the raw water inlet 86 facing vertically downward and the air vent 88 facing upward. The air vent 88 is closed during the separation operation. The raw water pumped by a pump or the like is supplied to the raw water inlet 86, the raw water distribution pipe 54, and the raw water supply port 4.
, Flows along the outer surface of the hollow fiber membrane 2 toward the free end, and is filtered by the hollow fiber membrane 2 during that time. The permeated water purified in the hollow fiber membrane 2 by filtration is passed through the permeated water chamber b.
And is taken out from the outlet 90 through the permeated water take-out pipe 72 and the water collecting pipe 87. On the other hand, the non-permeated water concentrated by filtration is discharged from the drain port 89.

In this module container 80, the hollow fiber membrane 2
Are stored in the rigid tube 83 for each module 81, so that the hollow fiber membrane 2 can be erected so that the free end faces upward. Since the free end faces upward, that is, in the downstream direction of the flow of the raw water, the solid is discharged from the drain port 89 without remaining. Therefore, excellent film performance is maintained. Further, when solid matter is deposited on the membrane surface of the hollow fiber membrane 2, air can be blown from the raw water inlet 86, and the solid matter can be separated and removed by the bubbles. The air vent 88 is opened at this time to release the air.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a longitudinal sectional view showing the collective hollow fiber membrane module container of the second embodiment. This assembly type hollow fiber membrane module container has basically the same structure as that of the first embodiment, except that a through hole 73 is formed in a side surface of the cylinder 83 near the head end.
Is provided. Thus, the through hole 73
By providing air, it is easy to separate solid matter on the membrane surface with water and bubbles flowing in from the outside of the cylinder through the through hole by the air lift effect when cleaning by blowing air.

[0020]

EXAMPLE Turbid water was separated using a collective hollow fiber membrane module container 80 shown in FIGS. 1 and 5 containing 30 hollow fiber membrane modules each having a membrane area of 7.5 m ² . As the turbid water, one obtained by adding iron oxide as a simulated turbid substance to water was used. When about 10 g of iron oxide in terms of iron per 1 m ^{2 of the} membrane area was attached, the operation was stopped, the air vent 88 was opened, and air was blown from the raw water inlet 86. The amount of air blown was 0.1 Nm ³ / h per m ² of film area. Then, the iron concentration in the collective module container 80 was measured over time, and the rate at which the removed iron oxide was discharged from the cylinder 83 was evaluated using the change over time in the iron concentration as an index. The evaluation results are shown in a graph in FIG. The solid line in the graph represents the result of the embodiment shown in FIG. 5, and the broken line represents the result of the embodiment shown in FIG.

As a result, in the collective hollow fiber membrane module container shown in FIG. 5, the iron concentration in the container equilibrated in about 5 minutes, but in the collective hollow fiber membrane module container shown in FIG.
It took five minutes.

[0022]

According to the present invention, since a plurality of modules with the free ends of the hollow fiber membranes facing upward are accommodated in one container, a liquid containing a high concentration of turbid matter can be maintained while maintaining the membrane performance. Can be processed in large quantities.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a collective hollow fiber membrane module container of a first embodiment.

FIG. 2 is a longitudinal sectional view of a module used for the assembly type hollow fiber membrane module container.

FIG. 3 is a sectional view taken along the line AA in FIG. 2;

FIG. 4 is a longitudinal sectional view showing a conventional hollow fiber membrane module.

FIG. 5 is a longitudinal sectional view showing an assembly type hollow fiber membrane module container of a second embodiment.

FIG. 6 is a graph showing the relationship between the turbidity concentration in the container and the elapsed time of the treatment in the process of separating turbid water using the collective hollow fiber membrane module container.

[Explanation of symbols]

 Reference Signs List 80 aggregate hollow fiber membrane module container 83 cylinder 85 header 82 flat plate 84 seat 87 water collecting pipe 72 permeated water outlet pipe 89 drain port 86 raw water inflow port 14 lid 13 main body 90 permeated water outlet 3,53 resin partition

Claims (4)

[Claims] 1. An external pressure hollow fiber membrane module having a structure in which one end of a hollow fiber membrane is fixed and the other end is free,
An assembly-type hollow fiber membrane module container, wherein the free end is mounted vertically in a single container. 2. The collective hollow fiber membrane module container according to claim 1, wherein said hollow fiber membrane is housed in a rigid cylinder for each module. 3. The collective hollow fiber membrane module container according to claim 2, wherein the cylinder has a through hole on a side surface near a fixed end of the hollow fiber membrane. 4. The method for cleaning a collective hollow fiber membrane module container according to claim 3, wherein air is blown into the cylinder from the fixed end side in a state where the processing liquid remains inside and outside the cylinder. And the washing method.