JPH11535A - External pressure type hollow fiber separation membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a module which easily shows an excellent separation efficiency and resistance against a muddy component by providing a conduit having an aperture at least at one position in a specified distance range to the axial direction of an outer cylinder from the resin partition wall surface so as to discharge the water to be treated from the outer cylinder. SOLUTION: The water to be treated supplied through a water supply port 1 is introduced into an outer cylinder 5 and treated by a hollow fiber bundle 7 which is bent into a U-shape. The both ends of the hollow fiber bundle 7 are open on the outer surface of a resin partition wall 6, and the openings 8 of the hollow fiber bundle are separated and sealed from the inside of the cylinder 5 by the resin partition wall 6. The water introduced into the cylinder 5 permeates through the outer surface of the hollow fiber under pressure to separate. The permeated water through the cross sectional direction of the hollow fibers bleeds through the openings 8 of the hollow fibers and is discharged to the outside through a permeated water outlet port 3. The water which is not permeated through the hollow fibers by the separation treatment is discharged to the outside through a conduit 9 and a water discharging port 2. The conduit 9 has an aperture within 50 mm distance to the axial direction from the surface of the resin partition wall 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external pressure type hollow fiber type separation membrane module used for separating solids or solutes from a liquid mixture or selectively permeating components in a gas mixture. The present invention relates to an external pressure type hollow fiber type separation membrane module which can be separated with high efficiency.

[0002]

2. Description of the Related Art Separation and concentration of a liquid mixture by a membrane method is an energy-saving method as compared with separation techniques such as distillation and does not involve a change in the state of a substance. Production of drinking water and industrial water by desalination of water and brine, production of ultrapure water in the electronics industry, production of aseptic water in the pharmaceutical industry and medical field, and other valuable resources from the water purification field or industrial wastewater It is widely used in various fields such as recovery of waste. Conventional gas separation methods include cryogenic separation method, adsorption method, absorption method, etc., compared to these technologies, the separation cost is lower when using the separation membrane method, the operation is simpler, and the equipment efficiency is lower. It has advantages such as high cost and easy maintenance, and is actively researched and developed.

[0003] These membrane separations are accomplished by using a membrane to more selectively permeate only certain components from a mixture. Therefore, the performance of the separation membrane is characterized by the permeation selectivity and permeation rate of the separation object. The permeation selectivity is defined, for example, in the case of a reverse osmosis membrane by the salt removal rate, and in the case of a gas separation membrane, by the separation coefficient. Similarly, the permeation rate is defined by the amount of permeated water and the amount of gas permeated per unit time.

[0004] Hollow fiber type, separation membrane module,
Spiral type, tubular type, flat membrane type, etc. are adopted.In particular, the hollow fiber type separation membrane module has a small amount of permeated water per unit membrane area, but can increase the membrane area per module because It is widely adopted because of its advantage that the amount of permeated water can be increased and the volumetric efficiency is high.

A conventional external pressure type hollow fiber type separation membrane module has a structure in which a hollow fiber membrane is wound around a porous core tube and both ends are fixed with an epoxy resin or the like into an outer cylinder. Examples thereof include those which are supplied vertically to the hollow fiber membrane via a tube, and those in which a hollow fiber membrane bundle fixed in a U-shape and fixed by a resin partition is accommodated in an outer cylinder.

However, in the former case, the flow rate of the treated water on the membrane surface is small, solute concentration on the membrane surface is high, and the separation efficiency and the permeation efficiency are deteriorated. In order to increase the separation efficiency, it is necessary to lower the recovery rate. In addition, the number of hollow fiber membranes is arranged in the outer cylinder as much as possible to increase the membrane area, and the flow rate at the membrane surface is small, so that the turbid components in the treated water are easily clogged in the hollow fiber membrane gap. There is a problem that the performance is seriously degraded due to the influence of.

[0007] The latter is mainly used for ultrafiltration membranes and microfiltration membranes in which total filtration is symmetrical, and can increase the flow rate of treated water on the surface of the hollow fiber membrane. However, there is an advantage that a rise in concentration can be suppressed, but there is a problem that a drift is easily generated. In particular, when a reverse osmosis membrane is used for the hollow fiber membrane, it has been considered that the separation efficiency is remarkably reduced and is not suitable for practical use.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problem. A hollow fiber bundle bent in a U-shape is accommodated in an outer cylinder, and one end of the outer cylinder is provided with a resin partition wall. , And both ends of the hollow fiber membrane bent in the U-shape are open to the outer surface of the resin partition wall. By providing a conduit having an opening for discharging the water to be treated from inside the outer cylinder at at least one position within a range of 50 mm, a module capable of easily exhibiting excellent separation efficiency and turbidity-resistant components is provided. The purpose is to provide.

[0009]

That is, according to the present invention, a hollow fiber bundle bent in a U-shape is accommodated in an outer cylinder having a treated water supply port, a treated water discharge port and a permeated water outlet. One end is fixed by a resin partition, and both ends of the hollow fiber membrane bent in the U-shape are opened on the outer surface of the resin partition, and the inside of the outer cylinder and the opening are made liquid-tight by the resin partition. In the external pressure type hollow fiber type separation membrane module, a conduit having an opening for discharging water to be treated from inside the outer cylinder at at least one position within a range of 50 mm in the axial direction from the surface of the resin partition in the outer cylinder. , And one end of the conduit is communicated with a treated water discharge port, to provide an external pressure type hollow fiber type separation membrane module.

[0010] The external pressure type hollow fiber type separation membrane module referred to in the present invention contains a hollow fiber bundle bent in a U-shape in an outer cylinder having a treated water supply port, a treated water discharge port and a permeated water outlet. One end of the outer cylinder is fixed by a resin partition, and both ends of the hollow fiber membrane bent into a U-shape are opened on the outer surface of the resin partition, and the inside of the outer cylinder and the opening are sealed by the resin partition. This is a dense external pressure type hollow fiber type separation membrane module, and is not limited to a method for producing the same.

The high molecular weight polymer for forming the hollow fiber type separation membrane used in the present invention includes cellulose acetates, polyamides, polyamide hydrazides, polyureas, polyvinyl alcohols, polysulfones, polyacrylonitriles, and carbonized polymers. Hydrogen or the like is used alone or as a mixture, but is not particularly limited thereto.

Further, some separation membranes have an active layer and a support layer whose structure is composed of an active layer and a support layer. An element in which the active layer and the support layer are made of the same material is called an asymmetric membrane. Are called composite membranes. An asymmetric membrane can be obtained by a phase inversion method, while a composite membrane is formed by forming a support membrane serving as a support layer in the same operation as the asymmetric membrane,
It can be obtained by forming a thin active layer on the surface of this by a coating method, an interfacial polymerization method, a plasma polymerization method or the like. The hollow fiber type separation membrane used in the present invention is not limited to these structures and production methods.

Further, the shape of the hollow fiber type separation membrane is not particularly limited, and the separation performance is not limited.

In the external pressure type hollow fiber type separation membrane module of the present invention, the material of the outer cylinder and the conduit having an opening in the outer cylinder includes vinyl chloride, polystyrene, polyethylene, polypropylene, polyacrylate, polycarbonate, polysulfone, FRP and the like. But are not particularly limited to these.

In the external pressure type hollow fiber type separation membrane module of the present invention, epoxy resin,
Examples thereof include a polyurethane resin and a polyester resin, but are not particularly limited thereto.

The filling rate of the hollow fiber bundle in the external pressure type hollow fiber type separation membrane module of the present invention is preferably 35 to 75%,
40 to 60% is more preferred. If the filling ratio is less than 35%, drifting of treated water is likely to occur and the separation efficiency is reduced.
If it is more than 5%, clogging in the hollow fiber gap due to the turbid component in the treated water is accelerated, so that the separation efficiency tends to be reduced.

The length / diameter ratio of the hollow fiber bundle in the external pressure type hollow fiber type separation membrane module of the present invention is preferably from 4 to 20, more preferably from 4 to 15. When the length / diameter ratio is less than 4, the separation efficiency is reduced due to the uneven flow of the treated water, and when it is larger than 20, the pressure loss in the module is liable to occur and the separation efficiency is reduced.

In the conduit having an opening in the external pressure type hollow fiber type separation membrane module of the present invention, the shape and number of the openings and the number of conduits are not particularly limited. The number is preferably one. Further, the position of the opening in the conduit must be provided within a range of 50 mm in the axial direction from the surface of the resin partition inside the outer cylinder. If it is larger than 50 mm, the dead space in the outer cylinder increases, and the separation efficiency decreases due to a decrease in the effective length of the hollow fiber membrane and a drift of treated water. Also, one end of the conduit needs to communicate with the treated water discharge port.

The structure of the external pressure type hollow fiber type separation membrane module of the present invention will be described below with reference to the drawings. 1 to 4 show examples of an external pressure type hollow fiber type separation membrane module according to the present invention, and FIGS. 5 and 6 show examples of a conventional external pressure type hollow fiber type separation membrane module. .

1 to 4, reference numeral 1 denotes a treated water supply port;
Denotes an outlet for treated water, and 3 denotes an outlet for permeated water.
The treated water supplied from 1 is treated by the hollow fiber bundle 7 guided into the outer cylinder 5 and bent into a U-shape. Both ends of the hollow fiber bundle 7 are fixed to one end of the outer cylinder by a resin partition 6 and are opened on the outer surface of the resin partition 6, and the inside 5 of the outer cylinder and the hollow fiber bundle opening 8 are separated by the resin partition 6. It is dense. The treated water guided to the inside of the outer cylinder 5 is press-fitted from the outer surface of the hollow fiber and separated, and the permeated water passing through the hollow fiber in the cross-sectional direction permeates through the hollow fiber through the hollow fiber bundle opening 8. However, it is led out of the system from the permeate outlet. On the other hand, the water to be treated that has not permeated the hollow fiber during the separation treatment is discharged out of the system through the treated water discharge port 2 through the conduit 9 having the opening.

The arrangement of the treated water supply port 1, the treated water discharge port 2 and the permeated water outlet 3 is not particularly limited, but the treated water supply port 1 is preferably installed at a position as far as possible from the resin partition wall 6. This is because the drift in the outer cylinder is reduced and the dead space can be minimized, so that stable performance can be exhibited.

[0022]

According to the external pressure type hollow fiber type separation membrane module of the present invention, since the fluid flows uniformly without creating a drift, concentration polarization does not occur and a high permeation selectivity can be achieved. It is possible to provide a module that can exhibit excellent separation efficiency and turbidity component properties. Such an external pressure type hollow fiber type separation membrane module according to the present invention is, for example, a membrane separation process used for desalination by desalination of seawater or brackish water for the purpose of producing drinking water, industrial water, etc. It can be suitably used for separating components of a gas mixture.

[0023]

The present invention will be described below with reference to examples and comparative examples, but the examples given here do not limit the present invention.

Example 1 The structure of a hollow fiber type separation membrane module is as shown in FIG. As the conduit having an opening, one having three holes each having a diameter of 3 mm as shown in FIG. 7A was used, and the distance from the resin partition wall surface in the outer cylinder was set to 20 to 25 mm. A hollow fiber type reverse osmosis membrane made of a cellulose triacetate having an outer diameter of 165 μm and an inner diameter of 64 μm, and provided with crimps having an amplitude of 500 μm at a length of 15 hollow fibers per 10 cm length is formed into a U-shaped hollow fiber bundle, 65m inside diameter
The length / diameter ratio of the hollow fiber bundle to the pressure-resistant outer cylinder of m is 330 mm is 4.5, and the filling rate of the hollow fiber bundle into the pressure-resistant outer cylinder is 50%.
And fixed with resin. The performance of the hollow fiber type reverse osmosis membrane used for making the module was as follows: the amount of permeated water was 60 l under the evaluation conditions of sodium chloride concentration in the supply liquid: 35000 mg / l, supply liquid temperature: 25 ° C., operating pressure: 55 kg / cm ^2. / M ² days, the removal rate of sodium chloride was 99.9%.

The obtained external pressure type hollow fiber type separation membrane module was subjected to a sodium chloride concentration of 35,000 mg /
1, supply liquid temperature: 25 ° C, operating pressure: 55Kg / c
Reverse osmosis performance was confirmed under the conditions of m ² , recovery rate: 30% and 50%. Table 1 shows the results. Both the amount of permeated water and the salt removal rate were satisfactory.

Example 2 The structure of the hollow fiber type separation membrane module is as shown in FIG. As the conduit having an opening, one having five holes each having a diameter of 2 mm on the side face as shown in FIG. 7A was used, and the distance from the resin partition wall surface in the outer cylinder was set to 10 to 15 mm. A hollow fiber bundle made of a cellulose triacetate having an outer diameter of 175 μm and an inner diameter of 84 μm, and a hollow fiber type reverse osmosis membrane provided with 15 crimps per 10 cm length of the hollow fiber and having an amplitude of 500 μm is formed into a U-shaped hollow fiber bundle, 54m inside diameter
The length / diameter ratio of the hollow fiber bundle is 5.2 in the pressure-resistant outer cylinder with m length of 290 mm, and the filling rate of the hollow fiber bundle into the pressure-resistant outer cylinder is 50%.
And fixed with resin. The performance of the hollow fiber type reverse osmosis membrane used for making the module was as follows: the sodium chloride concentration in the supply liquid: 500 mg / l, the supply liquid temperature: 25 ° C., the operating pressure: 3 kg / cm ² , and the permeated water amount was 21 l. / M ² days, removal rate of sodium chloride is 9
It was 5.4%.

The obtained external pressure type hollow fiber type separation membrane module was subjected to a sodium chloride concentration in a feed solution of 500 mg / l,
Reverse osmosis performance was confirmed under the conditions of feed liquid temperature: 25 ° C., operating pressure: 3 kg / cm ² , and recovery rate: 50% and 75%.
Table 1 shows the results. Both the amount of permeated water and the salt removal rate were satisfactory.

Example 3 The structure of the hollow fiber type separation membrane module is as shown in FIG. As the conduit having an opening, a hollow tube having an inner diameter of 5 mm as shown in FIG. 7B was used, and the distance from the surface of the resin partition in the outer cylinder to the opening was set to 20 mm. Outer diameter 300μ
m, a hollow fiber type ultrafiltration membrane made of aromatic polysulfone having an inner diameter of 200 μm is formed into a U-shaped hollow fiber bundle, and the length of the hollow fiber bundle is set in a pressure-resistant outer cylinder having an inner diameter of 54 mm and a length of 330 mm. The hollow fiber bundle was inserted so that the diameter ratio was 6.0 and the filling rate of the hollow fiber bundle into the pressure-resistant outer cylinder was 45%, and this was fixed with resin. The performance of the hollow fiber type ultrafiltration membrane used for making the module was determined by dextran (molecular weight: 10
10,000) Concentration: 300 ppm, supply liquid temperature: 25 ° C., operating pressure: 1 kg / cm ² , and the amount of permeated water is 1,5 under the evaluation conditions.
At 001 / m ² days, the dextran removal was 90.2%.

The obtained external pressure type hollow fiber type separation membrane module was subjected to dextran (molecular weight: 100,000) concentration in the feed solution:
300 ppm, supply liquid temperature: 25 ° C, operating pressure: 1 kg
/ Cm ² , the recovery rate was 70% and 90%, and the ultrafiltration membrane performance was confirmed. Table 2 shows the results.
Both the amount of permeated water and the dextran removal rate were satisfactory.

Comparative Example 1 Example 2 was followed except that the conventional type shown in FIG. 5 was employed as the module structure. Table 1 shows the results. At a recovery rate of 50%, good performance was maintained, but at a recovery rate of 75%, both the amount of permeated water and the salt removal were reduced. This suggests that a drift has occurred in the module.

Comparative Example 2 Example 3 was followed except that the conventional type shown in FIG. 6 was used as the module structure. Table 2 shows the results. Even at a recovery rate of 70%, both the amount of permeated water and the salt removal were reduced. This suggests that the treated water discharge port provided on the side surface of the outer cylinder is blocked by the hollow fiber bundle, and that a drift has occurred in the module.

[0032]

[Table 1]

[0033]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a view showing an example of an external pressure type hollow fiber type separation membrane module according to the present invention.

FIG. 2 is a view showing an example of an external pressure type hollow fiber type separation membrane module according to the present invention.

FIG. 3 is a diagram showing an example of an external pressure type hollow fiber type separation membrane module according to the present invention.

FIG. 4 is a view showing an example of an external pressure type hollow fiber type separation membrane module according to the present invention.

FIG. 5 is a view showing an example of a conventional external pressure type hollow fiber type separation membrane module.

FIG. 6 is a view showing an example of a conventional external pressure type hollow fiber type separation membrane module.

FIG. 7 shows an example of a conduit having an opening.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 treated water supply port 2 concentrated water discharge port 3 permeated water outlet 4 outer cylinder 5 inner cylinder 6 resin partition wall 7 hollow fiber bundle bent in U-shape 8 hollow fiber bundle opening 9 conduit with opening 10 treated water Supply core pipe 11 O-ring 12 Opening

Claims (5)

[Claims] 1. A hollow fiber bundle bent into a U-shape is accommodated in an outer cylinder having a treated water supply port, a treated water discharge port, and a permeated water outlet, and one end of the outer cylinder is fixed by a resin partition. An external pressure type hollow fiber type separation membrane module in which both ends of the hollow fiber membrane bent in a U-shape are opened on the outer surface of a resin partition, and the inside and the opening are made liquid-tight by the resin partition. In the axial direction from the surface of the resin partition in the outer cylinder
mm, a conduit having an opening for discharging the water to be treated from inside the outer cylinder is provided at one position, and one end of the conduit communicates with the water to be treated discharge port. Pressure type hollow fiber separation membrane module. 2. The external pressure type hollow fiber type separation membrane module according to claim 1, wherein the filling rate of the hollow fiber bundle is 35 to 75%. 3. The external pressure type hollow fiber type separation membrane module according to claim 1, wherein the length / diameter ratio of the hollow fiber bundle is 4 to 20. 4. The external pressure type hollow fiber type separation membrane module according to claim 1, wherein the hollow fiber membrane forming the hollow fiber bundle is a reverse osmosis membrane. 5. A hollow fiber membrane forming a hollow fiber bundle,
The external pressure type hollow fiber according to any one of claims 1 to 4, wherein a hollow fiber membrane provided with 5 to 20 crimps having an amplitude of 0.5 to 10 times the outer diameter of the hollow fiber per 10 cm length is used. Mold separation membrane module.