JPH10216483A - Hollow fiber membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate occurrence of a membrane failure by the vibration displacement, etc., of hollow fiber membranes while assuring a high treatment capacity. SOLUTION: Partition plates 4 for dividing hollow fiber membrane bundles 2 to plural parts are fixed to fixing layers 3. These partition plates 4 partly protrude from the surfaces of the fixing parts 3 and the front ends of the protruding parts are formed to a convergent shape by tapering or chamfering. As a result, the parts near the fixing layers 3 of the hollow fiber membranes are supported by the partition plates 4 and the excessive deformation of the hollow fiber membranes is suppressed when the hollow fiber membranes are deformed by the vibration at the time of membrane washing, by which the membrane failure is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a hollow fiber membrane module used for separating components in a liquid.

[0002]

2. Description of the Related Art Various separation membrane modules such as a hollow fiber membrane module, an annular membrane module, a spiral membrane module, and a pleated membrane module are used to separate components in a liquid. In particular, the hollow fiber membrane module has advantages such as a large membrane area per unit volume (volume efficiency), a simple seal between the undiluted solution and the permeated solution, and a small number of types of constituent members and a small size. Therefore, it is used in various fields such as ultrafiltration, reverse osmosis, dialysis, and crystal separation.

In a conventional external pressure type hollow fiber membrane module, since a large number of hollow fiber membranes are densely arranged in a cross section, a gap between the hollow fiber membranes is narrow, which becomes a resistance when a stock solution flows. . Therefore, when the stock solution is processed, there is a problem that the stock solution does not penetrate to the center of the hollow fiber membrane bundle, and the originally expected processing capacity cannot be obtained. This becomes more remarkable as the diameter of the hollow fiber membrane bundle increases, and it becomes difficult to perform uniform membrane separation over the entire hollow fiber membrane bundle. Therefore,
A hollow fiber membrane module capable of performing uniform membrane separation over the entire hollow fiber membrane bundle has been proposed.

FIGS. 5 and 6 are cross-sectional views of the proposed external pressure type hollow fiber membrane module. FIG. 5 shows a module of a type in which a permeate transmitted through a hollow fiber membrane bundle is taken out at both ends of a cylindrical case, and FIG. 6 shows a type in which a permeate transmitted through a hollow fiber membrane bundle is taken out at one end side of a cylindrical case. Module.

In the hollow fiber membrane module shown in FIG. 5, a number of thin hollow fiber membranes are bundled into one at substantially equal intervals to form a hollow fiber membrane bundle 2.
1, the hollow fiber membrane bundle 21 is housed in the cylindrical case 20, and both ends of the hollow fiber membrane bundle 21 are fixed to the fixed layers 22 at both ends of the cylindrical case 20 with a resin adhesive. ing. On the outer surface of the fixed layer 22, the end face of each hollow fiber membrane is formed so as to be open.

The hollow fiber membrane module shown in FIG.
Only one end of the hollow fiber membrane bundle 31 is fixed to the fixed layer 22 formed at one end of the cylindrical case 20.

In the hollow fiber membrane module shown in FIGS. 5 and 6, a partition plate 23 is arranged in a fixed layer 22 to divide the hollow fiber membrane bundle into a plurality of portions. By providing a gap in the central portion of the hollow fiber membrane bundle using this partition plate 23,
The undiluted solution easily flows into the central portion of the hollow fiber membrane bundle 21,
It is possible to perform uniform membrane separation over the entire hollow fiber membrane bundle 21.

[0008]

FIG. 7 is a partially enlarged view of the hollow fiber membrane module shown in FIG. 5 and FIG. FIG.
As shown in (1), in the conventional hollow fiber membrane module, the partition plate 23 is embedded in the fixed layer 22. For this reason,
In the hollow fiber membrane 21a facing the gap 40 between the hollow fiber membranes formed by the partition plate 23, the hollow fiber membrane 21 is easily deformed toward the gap 40,
On the side opposite to the gap 40, deformation is prevented by the adjacent hollow fiber membrane.

When the hollow fiber membrane bundle 21 is vibrated by air bubbling for cleaning the membrane, the hollow fiber membrane 21a particularly adjacent to the gap 40 is largely displaced toward the gap 40, and such displacement is repeated. . For this reason, the hollow fiber membrane 21a
The bending action is repeatedly applied to the vicinity of the boundary portion between the hollow fiber membrane and the fixed layer 22, causing a problem that the root A of the hollow fiber membrane is damaged.

An object of the present invention is to provide a hollow fiber membrane module which ensures high processing performance and does not cause membrane breakage due to vibration of the hollow fiber membrane bundle.

[0011]

Means for Solving the Problems and Effects of the Invention In the hollow fiber membrane module according to the present invention, a hollow fiber membrane bundle formed by bundling a plurality of hollow fiber membranes is housed in a cylindrical case, and at least one of the hollow fiber membranes is provided. In a hollow fiber membrane module having one end fixed to a fixed layer provided at an end of a cylindrical case, a partition plate for partitioning the hollow fiber membrane bundle into a plurality of portions is formed from a hollow fiber membrane in the cylindrical case from within the fixed layer. It is provided so as to protrude between them.

In the hollow fiber membrane module according to the present invention, since a gap is formed in the hollow fiber membrane bundle by the partition plate,
The undiluted solution sufficiently penetrates to the center of the hollow fiber membrane bundle, and high processing capacity is secured.

[0013] Further, the root portion of the hollow fiber membrane near the fixed layer is indicated by a partition plate protruding between the hollow fiber membranes from within the fixed layer. Thus, when the hollow fiber membrane vibrates due to air bubbling for membrane cleaning, concentration of excessive bending stress on the root portion of the hollow fiber membrane is suppressed, and breakage of the hollow fiber membrane is prevented.

In particular, it is preferable that the thickness of the tip of the partition plate projecting between the hollow fiber membranes is made smaller than the thickness of the base of the partition plate projecting between the hollow fiber membranes on the fixed layer side. This prevents the root of the hollow fiber membrane near the fixed layer from being bent by the base on the fixed layer side of the partition plate, while allowing the hollow fiber membrane to vibrate in the vicinity of the tip of the partition plate, and The bending of the hollow fiber membrane at the portion can be suppressed. Therefore, it becomes possible to sufficiently clean the hollow fiber membrane while preventing damage to the hollow fiber membrane.

In particular, it is preferable that at least the tip of the partition plate projecting between the hollow fiber membranes has a tapered cross section in the thickness direction. This allows the hollow fiber membrane to be displaced near the distal end of the partition plate while preventing the hollow fiber membrane from being damaged by the edge of the distal end of the partition plate.

In particular, it is preferable to chamfer an edge along a width direction of a leading end of the partition plate protruding between the hollow fiber membranes. This allows the hollow fiber membrane to be displaced near the distal end of the partition plate while preventing the hollow fiber membrane from being damaged by the edge of the distal end of the partition plate.

[0017]

FIG. 1 is a sectional view of an external pressure type hollow fiber membrane module according to the present invention. In the external pressure type hollow fiber membrane module shown in FIG. 1, a plurality of thin hollow fiber membranes are bundled at substantially equal intervals, and both ends of a hollow fiber membrane bundle 2 are made of a thermosetting resin such as urethane resin or epoxy resin. Is formed by casting into the openings at both ends. Fixed layers 3, 3
On the outer surface of the hollow fiber membrane bundle 2, the end face of each hollow fiber membrane of the hollow fiber membrane bundle 2 is open and constitutes a permeate outlet. The cylindrical case 1 is formed with a stock solution inlet 1a and a concentrated solution outlet 1b.

The hollow fiber membrane bundle 2 is divided into a plurality of parts by a partition plate 4. FIG. 2 is an enlarged view near the partition plate 4 in FIG. The partition plate 4 includes a buried portion 4c buried inside the fixed layer 3, a root portion 4b protruding from the surface of the fixed layer 3, and a tip portion 4a. Buried part 4c and base part 4b
Are formed in the same thickness, and the tip 4a is tapered to form a tapered shape. Although not shown, the tip 4a may be chamfered.

The length of the hollow fiber membrane bundle 2 between the fixed layers 3 is 3
The thickness of the partition plate 4 is 3 mm to 10 mm
mm, the portions (4a, 4a) protruding from the fixed layer 3
b) The length is about 5 to 40 mm, and the root portion 4b
Is formed to a length of about 3 to 10 mm. The tip 4a is tapered by 5 to 20 degrees. Alternatively, chamfering of R3 to 5 (radius of 3 to 5 mm) may be applied to the distal end portion 4a.

As described above, by forming the partition plate 4 so as to protrude from the surface of the fixed layer 3, even when the hollow fiber membrane vibrates due to air bubbling during membrane washing, for example, the root portion 4b and the tip The portion near the fixed layer 3 of the hollow fiber membrane is supported by the portion 4a, and excessive deformation of the hollow fiber membrane is suppressed. In particular, by forming the tip 4a into a tapered shape by tapering or chamfering, deformation of the hollow fiber membrane near the tip 4a is allowed, and the hollow fiber membrane is damaged by the edge of the tip 4a of the partition plate 4. Can be prevented.

FIG. 3 is a partially enlarged view of a hollow fiber membrane module using a partition plate according to another example. In FIG. 3, the partition plate 14 includes a buried portion 14 c buried in the fixed layer 3 and a protrusion 14 a protruding from the surface of the fixed layer 3. The entire protrusion 14a is formed in a tapered shape.
Even with such a shape, the portion of the hollow fiber membrane displaced toward the partition plate 14 in the vicinity of the fixed layer 3 can be supported, and breakage of the hollow fiber membrane can be prevented. Further, the tapered protrusion 1
The edge portion 4a may be chamfered.

FIG. 4 is a sectional view showing another example of the external pressure type hollow fiber membrane module according to the present invention. In this external pressure type hollow fiber membrane module, only one end of the hollow fiber membrane bundle 2 is fixed to the fixed layer 3 formed at one end of the cylindrical case 10. Then, the partition plate 4 is fixed to the fixed layer 3. As the shape of the partition plate 4, either the partition plate 4 shown in FIG. 2 or the partition plate 14 shown in FIG. 3 can be applied. This suppresses excessive bending displacement of the hollow fiber membrane,
The breakage of the hollow fiber membrane bundle 2 can be prevented.

[0023]

EXAMPLES Here, external pressure type hollow fiber membrane modules of Examples and Comparative Examples were prepared, and the presence or absence of breakage of the hollow fiber membrane due to vibration displacement was compared.

In the hollow fiber membrane module of the embodiment, as shown in FIG. 1, 3,200 hollow fiber membranes made of polysulfone having an outer diameter of 1.6 mm are inserted into the cylindrical case 1, and both ends thereof are fixed with resin. The partition plate 4 is fixed so that the hollow fiber membrane bundle 2 is divided into four in the fixed layers 3 at both ends. The length of the hollow fiber membrane bundle 2 between the fixed layers 3 is 3 mm, and the thickness of the partition plate 4 is 10 mm. The partition plate 4 is embedded 20 mm in the fixed layer 3 and protrudes 20 mm from the fixed layer 3. Also, of the protruding portions, a portion 10 mm from the surface of the fixed layer 3 is
It is formed to the same thickness as the part embedded in the
The 0 mm portion was tapered at 10 degrees to form a tapered shape. Further, the hollow fiber membrane module of the comparative example had the structure shown in FIG. 5 and was manufactured so that the partition plate 23 did not protrude from the fixed layer 22.

With respect to the hollow fiber membrane modules of this example and the comparative example, the pressure was 2 kg / cm ² and the air amount was ² Nm ^3.
An air bubbling test in which air was continuously introduced into the hollow fiber membrane module for 100 hours under the conditions of / h was performed, and then an air leak test was performed to check whether the hollow fiber membrane was damaged.

As a result of the above test, five hollow fiber membranes were damaged in the hollow fiber membrane module of the comparative example, but no membrane damage was generated in the hollow fiber membrane module of the example.

As described above, by projecting the partition plate from the surface of the fixing portion and forming the tip thereof into a tapered shape,
Excessive bending deformation of the hollow fiber membrane can be suppressed, and membrane breakage can be prevented.

[Brief description of the drawings]

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

FIG. 2 is an enlarged view near a partition plate in FIG.

FIG. 3 is an enlarged view showing another example of the partition plate of the hollow fiber membrane module according to the present invention.

FIG. 4 is a sectional view showing another example of the hollow fiber membrane module according to the present invention.

FIG. 5 is a sectional view showing an example of a conventional hollow fiber membrane module.

FIG. 6 is a cross-sectional view showing another example of a conventional hollow fiber membrane module.

FIG. 7 is an enlarged view near a partition plate in FIGS. 6 and 7;

[Explanation of symbols]

 1, 10 cylindrical case 2 hollow fiber membrane bundle 3 fixing layer 4, 14 partition plate 4a tip 4b root 4c, 14c burying portion 14a projecting portion

Claims (4)

[Claims] A hollow fiber membrane bundle formed by bundling a plurality of hollow fiber membranes is housed in a cylindrical case, and at least one end of the hollow fiber membrane is fixed to a fixed layer provided at an end of the cylindrical case. In the hollow fiber membrane module, a partition plate for dividing the hollow fiber membrane bundle into a plurality of portions is provided so as to protrude from within the fixed layer between the hollow fiber membranes in the cylindrical case. Hollow fiber membrane module. 2. The method according to claim 1, wherein a thickness of a tip portion of the partition plate projecting between the hollow fiber membranes is formed smaller than a thickness of a base portion of the partition plate projecting between the hollow fiber membranes on a fixed layer side. The hollow fiber membrane module according to claim 1, wherein 3. The hollow fiber membrane module according to claim 2, wherein a cross section in a thickness direction of at least a front end portion of said partition plate protruding between said hollow fiber membranes is formed in a tapered shape. 4. The hollow fiber membrane module according to claim 2, wherein an edge along a width direction of a front end of the partition plate protruding between the hollow fiber membranes is chamfered.