JP2014226618A - Hollow fiber membrane module and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow fiber membrane module having a hollow fiber membrane excellent in durability.SOLUTION: A hollow fiber membrane 12a constituting a hollow fiber membrane bundle 12 is covered with a coating agent 14 in a range of a length L1 from one end thereof. The hollow fiber membrane bundle 12 is integrated with an adhesive agent 13 in a range of a length L2 from an end having the hollow fiber membrane 12a coated with the coating agent 14. L1>L2 is satisfied.

Description

  The present invention relates to a hollow fiber membrane module and a manufacturing method thereof.

Hollow membrane modules are widely used as water treatment means in various fields.
In the hollow fiber membrane module, hundreds or thousands of hollow fiber membranes are accommodated in a module case as a hollow fiber membrane bundle in which one or both ends thereof are integrated with an adhesive.
When a filtration operation is performed using a hollow membrane module, pressure is applied to the hollow fiber membrane bundle by the liquid entering and exiting the nozzle (raw water inlet, permeate outlet, concentrated water outlet, etc.) of the module case.
For this reason, in the process of continuing the filtration operation, the hollow fiber membrane may be damaged (for example, a hole may be opened or torn) and a liquid leakage (leakage) may occur, which is one of the factors that lower the filtration performance. Therefore, development of means capable of improving the strength (durability) of the hollow fiber membrane is required.

JP-A-4-293527 Japanese Patent Laid-Open No. 2-107318 Japanese Patent Laid-Open No. 11-033366 Japanese Patent Laid-Open No. 11-033365 JP-A-9-225269 Japanese Patent Laid-Open No. 7-251039

  An object of the present invention is to provide a hollow fiber membrane module in which the durability of the hollow fiber membrane accommodated in the module case is improved, and a method for producing the same.

The present inventors have completed the present invention by paying attention to the fact that when the filtration operation is continued using the hollow fiber membrane module, damage to the hollow fiber membrane occurs particularly in a portion in contact with the adhesive layer.
As a means for solving the problems, the present invention
A hollow fiber membrane module in which a hollow fiber membrane bundle is accommodated in a module case,
The hollow fiber membranes constituting the hollow fiber membrane bundle are covered with a synthetic resin coating agent in a range of length L1 from at least one end side thereof,
Further, the hollow fiber membrane bundle is integrated with an adhesive in the range of the length L2 from the end of the hollow fiber membrane coated with a synthetic resin coating agent,
The synthetic resin coating agent is selected from a thermosetting resin adhesive and a thermoplastic resin adhesive,
Provided are a hollow fiber membrane module in which the relationship between the lengths L1 and L2 is L1> L2, and a method for manufacturing the same.

  In the hollow fiber membrane module of the present invention, the strength of the hollow fiber membrane in contact with the adhesive layer that integrates the required number of hollow fiber membranes is increased, and therefore when the filtration operation is continued for a long period of time. Even if it exists, it is hard to damage a hollow fiber membrane and it is hard to generate | occur | produce the liquid leak (leak) from a hollow fiber membrane.

It is sectional drawing of the axis X direction (length direction) of the hollow fiber membrane module of this invention, and has shown in the state which cut off about half of the module case so that the inside could be seen. Explanatory drawing of the preparation method of the hollow fiber membrane for a test. Explanatory drawing of the hollow fiber membrane module for a test.

<Hollow fiber membrane module>
This will be described with reference to FIG.
In the hollow fiber membrane module 10, a hollow fiber membrane bundle 12 including a required number (for example, several hundred to several thousand) of hollow fiber membranes 12 a is accommodated in a cylindrical module case 11.
In addition, the hollow fiber membrane module 10 may be one in which a water collecting pipe is disposed at the center portion of the axis X in the cylindrical module case 11 (inside the hollow fiber membrane bundle 12).

The hollow fiber membrane 12a constituting the hollow fiber membrane bundle 12 has a covering portion in which the range from the one end portion side (end surface 13b on the outer side in the axis X direction of the adhesive layer 13) to the length L1 is coated with a synthetic resin coating agent. 14
The hollow fiber membrane bundle 12 is integrated by the adhesive layer 13 in the range of the length L2 from one end side (end surface 13b on the outer side in the axis X direction of the adhesive layer 13).

The lengths L1 and L2 have a relationship of L1> L2.
For this reason, in the covering portion 14, a portion corresponding to the length L2 in the length L1 is embedded in the adhesive layer 13, and a portion corresponding to the length L3 (that is, L1-L2) is exposed from the adhesive layer 13. It is in the state that was done.
The covering portion 14 corresponding to the length L3 is in contact with the end surface 13a on the inner side in the axis X direction of the adhesive layer 13.

  The relationship between the lengths L1 and L2 is preferably in the range of L1 / L2 = 1.2 to 2.0, more preferably in the range of 1.3 to 1.8 in order to increase the durability of the hollow fiber membrane 12a. The range of 0.4 to 1.7 is more preferable.

  When the length of the hollow fiber membrane bundle 12 (hollow fiber membrane 12a) is 900 to 1100 mm, L1 is preferably in the range of 30 to 50 mm, and L2 is preferably in the range of 20 to 30 mm. At this time, L3 is preferably in the range of 10 to 20 mm.

The synthetic resin coating agent that forms the covering portion 14 and the adhesive agent that forms the adhesive layer 13 may be the same or different.
As the synthetic resin coating agent (not including paint) that forms the covering portion 14, a material selected from a thermosetting resin adhesive and a thermoplastic resin adhesive can be used. For this purpose, a thermosetting resin adhesive is preferred.
Examples of the thermosetting resin adhesive include an epoxy resin adhesive, a urethane resin adhesive, a phenol resin adhesive, an unsaturated polyester resin adhesive, a melamine resin adhesive, and a urea resin adhesive.

The hollow fiber membrane module 10 shown in FIG. 1 is shown having an adhesive layer 13 and a covering portion 14 only on one end side, but in order to enhance durability, it has the same structure on both end sides. Is preferred.
The cylindrical module case 11 is closed at one end by a cap 15a having liquid inlets 16a and 17a and at the other end by a cap 15b having liquid inlets 16b and 17b. The opening of the cylindrical module case 11 on the cap 15a side may be closed beforehand.

<Method for producing hollow fiber membrane module>
Next, the manufacturing method of the hollow fiber membrane module 10 shown in FIG. 1 is demonstrated.
In the first step, the covering portion 14 is formed by coating a range of the length L1 from at least one end side of the hollow fiber membrane 12a with a coating agent made of synthetic resin.
The method of coating with the synthetic resin coating agent in the first step is not particularly limited. For example, a method of immersing the hollow fiber membrane in a bath made of a synthetic resin coating agent, a synthetic resin coating The method etc. which apply | coat an agent to a hollow fiber membrane can be applied.
After the first step, a drying or drying / curing step can be provided as necessary. The drying or drying / curing step may be a drying method in which cold air or hot air is blown, a drying / curing method held in a heated atmosphere, or a method of natural drying during the transition to the next step.
Although the thickness of the coating | coated part 14 changes with kinds of coating agent to be used, for example, the thickness after drying (or drying and hardening) may be about 0.01 to 0.5 mm.

In the second step, the required number of hollow fiber membranes 12 a on which the covering portions 14 are formed are accommodated in the module case 11.
The module case 11 is a known one, and the size (inner diameter and length) is adjusted according to the number and length of the hollow fiber membranes 12a to be accommodated.

In the third step, the end of the required number of hollow fiber membranes 12a on which the covering portion 14 is formed (the end including the covering portion 14) and the inner wall surface 11a of the module case 11 facing the end are L2 in length. Integrate with adhesive so that it is within range.
As a method for forming the adhesive layer 13 and integrating the required number of hollow fiber membranes 12a, for example, a method described in JP-A-2006-281051 can be applied.

In a 4th process, the edge part (part used as the adhesive bond layer 13) of the hollow fiber membrane bundle 12 which protruded from the end surface of the cylindrical module case 11 and was integrated with the adhesive agent is cut | disconnected, and the hollow fiber membrane 12a Open.
At this time, the length L2 of the adhesive layer 13 after cutting is adjusted to a desired length.

  Then, according to the shape of the module case 11 used, a cap is put on and the opening is closed to obtain the hollow fiber membrane module 10.

During the filtration operation of the hollow fiber membrane module 10 of the present invention, the hollow fiber membrane 12a that is not fixed by the adhesive layer 13 receives the fluid pressure (pressure associated with the entry and exit of the permeate, concentrated solution, etc.) associated with the filtration operation. Shaking.
At this time, if the hollow fiber membrane 12a is a central portion in the length direction, a certain amount of pressure can be absorbed by shaking, but the portion of the hollow fiber membrane 12a in contact with the adhesive layer 13 is subjected to hydraulic pressure. The power is applied intensively by shaking.
For this reason, it becomes easy to generate | occur | produce especially a part (for example, a hole opens or tears) in the part which contact | connects the adhesive bond layer 13 of the hollow fiber membrane 12a at the time of filtration operation.

The hollow fiber membrane bundle 12 (hollow fiber membrane 12a) used in the hollow fiber membrane module 10 of the present invention has a part integrated with the adhesive layer 13 and a part embedded in the adhesive layer 13, and the remaining part Has a cover portion 14 that protrudes from the adhesive layer 13 and is exposed.
For this reason, since the strength (durability) of the portion of the hollow fiber membrane 12a in contact with the adhesive layer 13 is increased, the adhesive layer of the hollow fiber membrane 12a even when the filtration operation is continued for a long period of time. Since it is difficult for damage to occur at the portion in contact with 13, liquid leakage (leakage) is also less likely to occur.

Examples and Comparative Examples Using the following, the same test module as the hollow fiber membrane module shown in FIG. 1 was produced.
-Module case: Polysulfone, outer diameter 89mm, inner diameter 80mm, length 1066mm
・ Cap: Polysulfone ・ Hollow fiber membrane: Polyethersulfone, inner diameter 0.8mm, outer 1.3mm
-Adhesive used for the adhesive layer: Epoxy resin adhesive-Coating agent:
Heat-resistant urethane: urethane resin manufactured by Sanyu Rec Co., Ltd., main agent SA-7520B, curing agent SA-7520A
Epoxy: Epoxy resin manufactured by Japan Epoxy Resin Co., Ltd., main agent 815, curing agent ST12
Paint: Product name Water-based versatile (Asahi Pen Co., Ltd.), water-based synthetic resin paint (acrylic resin, pigment, rusting agent, antifungal agent, water)

As shown in FIG. 2, the hollow fiber membrane was coated with the same coating agent on the L1 length portion on one end side and the L1 length portion on the other end side.
Coating was carried out by immersing the hollow fiber membrane in a container containing a coating agent. After immersion, it was naturally dried at room temperature.
In this way, a test hollow fiber membrane was obtained (hollow fiber membrane shown in Table 1) in which both ends were coated with the same coating agent (three types each of urethane, epoxy, and paint were used). In addition, what also has what has not applied the coating agent to the both ends (blank) was produced.

  Next, the module case 11 was divided into four chambers with a partition plate. For each chamber, the hollow fiber membrane was filled with a coating part coated with the same coating agent (urethane, epoxy, or paint, respectively) and an uncoated one (number and filling shown in Table 1). rate).

The flux and air permeation amount of the test hollow fiber membrane module are as shown in Table 1, and it was confirmed that the test hollow fiber membrane module functions normally as a hollow fiber membrane module. Durability was evaluated by performing a heat shock test using this test hollow fiber membrane module. The results are shown in Table 1.
For example, in Comparative Example 1 of Table 1, “1 (1)” or “1 (2)” indicates that one leak occurred between 0 and 96 heat shock cycles (in parentheses). Shows the total number), and indicates that one leak occurred by 97 to 154 heat shock cycles (the total number in parentheses).

  As shown in Table 1, when Examples 1 and 2 were compared with Comparative Examples 1 and 2, it was confirmed that the durability of the hollow fiber membranes of Examples 1 and 2 was improved.

DESCRIPTION OF SYMBOLS 10 Hollow fiber membrane module 11 Module case 12 Hollow fiber membrane bundle 12a Hollow fiber membrane 13 Adhesive layer 14 Covering part

Claims (4)

A hollow fiber membrane module in which a hollow fiber membrane bundle is accommodated in a module case,
The hollow fiber membranes constituting the hollow fiber membrane bundle are covered with a synthetic resin coating agent in a range of length L1 from at least one end side thereof,
Further, the hollow fiber membrane bundle is integrated with an adhesive in the range of the length L2 from the end of the hollow fiber membrane coated with a synthetic resin coating agent,
The synthetic resin coating agent is selected from a thermosetting resin adhesive and a thermoplastic resin adhesive,
A hollow fiber membrane module in which the relationship between the lengths L1 and L2 is L1> L2.   The hollow fiber membrane module according to claim 1, wherein the relationship between the lengths L1 and L2 is in a range of L1 / L2 = 1.2 to 2.0.   The hollow fiber membrane module according to claim 1 or 2, wherein when the length of the hollow fiber membrane bundle is 900 to 1100 mm, the L1 is 30 to 50 mm and the L2 is 20 to 30 mm. It is a manufacturing method of the hollow fiber membrane module according to any one of claims 1 to 3,
A step of coating a range of length L1 from at least one end of the hollow fiber membrane with a synthetic resin coating agent;
A process of accommodating a required number of hollow fiber membranes in a module case;
A step of integrating at least one end of the required number of hollow fiber membranes and an inner wall surface of the module case directly facing it with an adhesive so that the length is in the range of L2,
The step of cutting the end portion of the bundle of hollow fiber membranes which is protruded from the end face of the cylindrical module case and integrated with the adhesive, and opens the hollow fiber membranes,
A process for producing a hollow fiber membrane module.

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