WO2017017777A1 - Hollow fiber membrane module - Google Patents

Abstract

Provided is a hollow fiber membrane module that can eliminate suspended matter adhering to hollow fiber membranes. Raw water flows through an inflow opening 1e, an inflow chamber 5, holes 4a, a treatment chamber 6, linking pipes 10, a discharge chamber 9, and a discharge opening 1f. Permeating water that has passed through the hollow fiber membranes 2 is extracted via an extraction opening 1g from a permeated water chamber 7. When bubbling cleaning is performed, air is supplied from the inflow opening 1e. Holes 4a and linking pipes 10 are provided uniformly over the entire area of potting parts 4, 3; therefore, sufficient bubbling cleaning occurs even in the upper parts of all the hollow fiber membranes 2.

Description

Hollow fiber membrane module

The present invention relates to a hollow fiber membrane module, and more particularly to a hollow fiber membrane module that can sufficiently wash away turbidity adhering to the membrane.

When performing filtration of polluted water using a hollow fiber membrane module with an external pressure method, if turbidity adheres to the hollow fiber membrane, the filtration life of the hollow fiber membrane module is shortened or the filtration flow rate is reduced. . Therefore, when turbidity adheres to the hollow fiber membrane, the turbidity is removed by backwashing or bubbling with air.

In conventional hollow fiber membrane modules, a bubbling air outlet is often provided on one side of the container directly below the upper potting portion. In this hollow fiber membrane module, bubbling air does not easily reach the hollow fiber membrane located on the side opposite to the discharge port, and cleaning is likely to be insufficient.

Patent Document 1 discloses a hollow fiber membrane in which an air discharge hole is provided in a peripheral portion of an upper potting portion that binds an upper portion of a hollow fiber membrane, and air during bubbling is discharged through the air discharge hole to an upper chamber of the upper potting portion. A module is disclosed. However, in the hollow fiber membrane module disclosed in Patent Document 1, bubbling air is collected at the peripheral portion of the upper potting portion, so that the hollow fiber membrane on the center side of the potting portion is not sufficiently cleaned.

Patent Literature 2 describes a hollow fiber membrane module in which a nozzle for supplying water to be treated (raw water) is provided at the center of the lower potting part, and a connecting pipe for discharging concentrated water is connected to the center part of the upper potting part. ing. In this hollow fiber membrane module, the fine particles are accommodated in a processing chamber in which the hollow fiber membranes are arranged, and the water to be treated is discharged from the nozzles in the radial direction so that the fine particles are disturbed, and the gel layer on the hollow fiber membranes. Prevent adhesion.

In the hollow fiber membrane module of Patent Document 2, the fine particles are difficult to reach the upper part of the processing chamber even if the fine particles are disturbed. For this reason, the upper part of the hollow fiber membrane tends to be insufficiently cleaned. In addition, since the connecting pipe is arranged at the central portion of the upper potting portion, the water to be treated and the fine particles are likely to gather at the central portion of the processing chamber. It tends to be insufficient.

JP-A-6-343836 Reality 4-41932

As described above, in Patent Document 1, the cleaning of the hollow fiber membrane on the center side of the potting portion tends to be insufficient, and in Patent Document 2, the cleaning of the hollow fiber membrane on the outer periphery side of the potting portion tends to be insufficient.

An object of the present invention is to provide a hollow fiber membrane module capable of removing turbidity adhering to the hollow fiber membrane evenly and sufficiently.

The hollow fiber membrane module of the present invention is a container in which a raw water inlet is provided in the lower part and a permeated water outlet and a concentrated water outlet are provided in the upper part, and a hollow fiber membrane for separating raw water into permeated water and concentrated water. A hollow fiber having a plurality of hollow fiber membranes arranged in the vertical direction in the container, and an upper potting portion arranged at the upper part in the container, the upper end portion of the hollow fiber membrane being fixed In the membrane module, a partition plate is provided above the upper potting portion, a concentrated water and bubbling air discharge chamber is provided above the partition plate, and permeated water is provided between the partition plate and the upper potting portion. A chamber is provided, the hollow fiber membrane communicates with the permeated water chamber, and a communication pipe that communicates the lower processing chamber of the upper potting portion and the discharge chamber has an entire area of the upper potting portion. Special features To.

In the present invention, it is preferable that a through hole is provided in each of the partition plate and the upper potting portion in the vertical direction, and an upper end and a lower end of the communication pipe are inserted into the through hole.

In addition, a lower potting portion that binds the lower ends of the hollow fiber membranes is provided, and the lower potting portion has an inflow chamber below the lower potting portion and an upper side of the lower potting portion throughout the lower potting portion. It is preferable that a communication hole communicating with the chamber is provided vertically.

When air is introduced into the lower part of the container for bubbling and washing the hollow fiber membrane module of the present invention, bubbling air flows out from the concentrated water outlet through the treatment chamber, the communication tube and the discharge chamber.

In the present invention, since the communication pipe is provided in the entire upper potting portion, the bubbling air uniformly contacts the upper part of all the hollow fiber membranes, and all the hollow fiber membranes are sufficiently washed, The membrane performance is fully restored.

In particular, by making holes vertically in the entire area of the lower potting part, bubbling air uniformly hits all the hollow fiber membranes, and turbidity is sufficiently removed from all the hollow fiber membranes. The

It is a typical longitudinal section of a hollow fiber membrane module concerning an embodiment of the present invention. It is a partial expanded sectional view of the hollow fiber membrane module which concerns on the same embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

As shown in FIG. 1, the hollow fiber membrane module includes a container 1 that is arranged with the axial direction of the cylinder in the vertical direction (vertical direction in this embodiment). The container 1 includes a cylindrical body 1A, a canopy body 1B, and a bottom cover body 1C. The trunk portion 1A, the canopy body 1B, and the bottom lid body 1C are connected by flanges 1a, 1b, and 1c, respectively. The bottom lid 1C is provided with an inlet 1e for raw water or bubbling air, and the canopy 1B is provided with a discharge port 1f for concentrated water or bubbling air. A treated water outlet 1g is provided on the upper portion of the body 1A.

A plurality of hollow fiber membranes 2 are arranged in the container 1. The upper end of the hollow fiber membrane 2 is fixed by an upper potting portion 3 made of synthetic resin, and the lower end is embedded in the lower potting portion 4 and sealed. As a synthetic resin for the potting portions 3 and 4, for example, an epoxy resin can be used. The potting parts 3 and 4 are installed horizontally.

The lower side of the lower potting portion 4 is an inflow chamber 5, and the space between the lower potting portion 4 and the upper potting portion 3 is a processing chamber 6. A partition plate 8 is installed substantially horizontally above the upper potting portion 3, and a permeated water chamber 7 is formed between the upper potting portion 3 and the partition plate 8. An upper side of the partition plate 8 is a discharge chamber 9.

The potting parts 3 and 4 are disk-shaped, and their outer peripheral surfaces are in watertight contact with the inner surface of the container 1. In FIG. 1, four hollow fiber membranes 2 are shown for the sake of clarity, but in reality, a large number of hollow fiber membranes 2 are arranged. The upper end side of the hollow fiber membrane 2 penetrates the potting portion 3, the opening at the upper end faces the permeate water chamber 7, and the inside of the hollow fiber membrane 2 communicates with the permeate water chamber 7.

A communication pipe 10 having an inner diameter of about 4 to 10 mm is provided so that the processing chamber 6 and the discharge chamber 9 communicate with each other. As shown in an enlarged view in FIG. 2, through holes 8a and 3a are vertically provided in the partition plate 8 and the upper potting portion 3, respectively, and the upper and lower ends of the communication pipe 10 are inserted into the holes 8a and 3a. Yes. The outer peripheral surface of the upper part of the tube 10 and the inner peripheral surface of the hole 8a, and the outer peripheral surface of the lower part of the tube 10 and the inner peripheral surface of the hole 3a are fixed in a watertight manner by an adhesive or the like. The holes 8a and 3a are evenly arranged over the entire area of the partition plate 8 and the upper potting 3. The communication pipe 10 is made of a water-impermeable material such as metal or synthetic resin.

In the lower potting portion 4, as shown in an enlarged view in FIG. 2, a communication hole 4a having an inner diameter of about 5 to 10 mm that connects the inflow chamber 5 and the processing chamber 6 is provided in the vertical direction. The holes 4 a are arranged uniformly over the entire area of the board surface of the lower potting portion 4.

When the raw water is treated and collected using the hollow fiber membrane module configured as described above, the raw water is supplied to the inlet 1e by a raw water supply device (not shown) having at least a raw water pump and piping. The raw water flows into the processing chamber 6 through the inlet 1e, the inflow chamber 5 and the hole 4a. While the raw water rises in the processing chamber 6, a part of the water permeates through the hollow fiber membrane 2, and the permeated water is taken out from the outlet 1 g through the permeated water chamber 7.

Water that has not permeated through the hollow fiber membrane 2 while rising in the processing chamber 6 is discharged out of the container 1 from the communication tube 10 through the discharge chamber 9 and the discharge port 1f as concentrated water.

If such raw water treatment operation is continued, turbidity will adhere to the hollow fiber membrane 2, so back washing and bubbling washing are performed. In order to perform backwashing, backwashing water (preferably permeated water of this hollow fiber membrane module) is supplied from the outlet 1g to the permeate water chamber 7, and the backwash waste water is discharged from the inlet 1e.

In order to perform bubbling cleaning, air or air and water (for example, raw water) is supplied from the inlet 1e while raw water or concentrated water is accumulated in the processing chamber 6, and the inside of the processing chamber 6 is bubbled. Air is supplied by an air pump and piping. As the bubbles rise in the processing chamber, the hollow fiber membrane 2 vibrates and the adhering suspended matter is peeled off. The separated turbidity is discharged from the discharge port 1 f through the communication pipe 10 and the discharge chamber 9.

After completion of the bubbling cleaning, rinsing water is introduced from the inlet 1e, and turbidity-containing water remaining in the processing chamber 6 is discharged from the outlet 1f. As the rinse water, raw water is sufficient, but other clean water may be used.

After performing such a cleaning process, restart the water sampling process.

In this cleaning process, since the holes 4a and the communication pipes 10 are evenly provided throughout the potting parts 4 and 3, the bubbling air uniformly contacts all the hollow fiber membranes 2, and all the hollow fiber membranes. 2 is sufficiently washed, and the performance of the hollow fiber membrane 2 is sufficiently restored. According to this embodiment, bubbling air uniformly hits all the hollow fiber membranes 2 even immediately below the upper potting portion 3, and turbidity is sufficiently removed even at the upper portions of all the hollow fiber membranes 2. The washed waste water containing the separated turbidity flows out into the discharge chamber 9 through the communication pipe 10 and therefore does not enter the permeated water chamber 7 at all.

When the arrangement density of the hollow fiber membranes 2 in the upper potting portion 3 is 300 to 600 per 100 cm ² (10 × 10 cm ² ), the arrangement density of the communication pipe 10 is 10 to 90, especially 50 to 100 per 100 cm ^2. The number is preferably about 70. In this case, the arrangement density of the holes 4a in the lower potting portion 4 is preferably about 10 to 90, particularly about 50 to 70 per 100 cm ² .

The above embodiment is an example of the present invention, and the present invention may be configured other than illustrated. For example, in the above embodiment, air is supplied from the inlet 1e, but an air inlet and an air nozzle may be provided separately from the inlet 1e. Further, a water passage gap may be provided between the outer periphery of the lower potting portion 4 and the inner peripheral surface of the container 1. Moreover, there is no lower potting part 4, and the lower end of the hollow fiber membrane 2 may be a free end. In this case, the lower end of the hollow fiber membrane is plugged (sealed).

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2014-114075 filed on Jun. 2, 2014, which is incorporated by reference in its entirety.

Claims (6)

A container in which a raw water inlet is provided in the lower part and a permeate outlet and a concentrated water outlet are provided in the upper part;
A hollow fiber membrane for separating raw water into permeated water and concentrated water, a plurality of hollow fiber membranes arranged in the vertical direction in the container,
In the hollow fiber membrane module, the upper end portion of the hollow fiber membrane is fixed, and the upper potting portion disposed in the upper part of the container,
A partition plate is provided above the upper potting portion,
A concentrated water and bubbling air discharge chamber is provided on the upper side of the partition plate,
A permeated water chamber is provided between the partition plate and the upper potting portion;
The hollow fiber membrane communicates with the permeate chamber,
A hollow fiber membrane module, characterized in that a communication pipe communicating the processing chamber below the upper potting portion and the discharge chamber is provided in the entire area of the upper potting portion. 2. The hollow fiber membrane module according to claim 1, wherein a through hole is provided in each of the partition plate and the upper potting portion in a vertical direction, and an upper end and a lower end of the communication pipe are inserted into the through hole. . In Claim 1 or 2, the lower side potting part which binds the lower end of the hollow fiber membrane is provided,
The lower side of the lower potting part is an inflow chamber,
Between the lower potting part and the upper potting part is the processing chamber,
A hollow fiber membrane module, characterized in that a communication hole for communicating the inflow chamber and the processing chamber is vertically provided in the entire area of the lower potting portion. 4. The hollow fiber according to claim 3, wherein the arrangement density of the hollow fiber membranes in the upper potting portion is 300 to 600 per 100 cm ² , and the arrangement density of the communication pipes is 10 to 90 per 100 cm ^2. Membrane module. 5. The hollow fiber membrane module according to claim 4, wherein the arrangement density of the communication holes in the lower potting portion is 10 to 90 per 100 cm ² . A method for cleaning a hollow fiber membrane module according to any one of claims 1 to 5, comprising a step of supplying air or air and water to a lower portion of the container and bubbling the processing chamber. Cleaning method.

Images