JPH11533A - Hollow fiber membrane filter cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the flowing resistance of a hollow fiber membrane in a tube to obtain a high flow, an to effectively use the whole membrane by providing water collecting rooms to collect the treated liquid permeated through the hollow fiber membrane on both ends of a cylindrical case and providing a water collecting tube in the cylindrical case to connect the two water collecting rooms. SOLUTION: A water collecting tube 4 is arranged in the center part of a cylindrical case 2 parallel to the hollow fiber membrane, and the both ends of the tube are fixed by fixing members 3, 3'. Water collecting rooms 5, 5' to collect the treated water permeated through the hollow fiber membrane 1 are attached by the fixing members 3, 3' to be separated and sealed from the water to be treated. The water collecting tube 4 is used for sending the liquid collected in the water collecting room 5' in the side where no coupling means is attached to the other water collecting room 5. The inner and outer diameters of the water collecting tube 4 are not limited whenever the tube can be disposed in the cylindrical case 2 and is thicker than the inner diameter of the hollow fiber membrane and the pressure loss during sending the treated liquid can be neglected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow fiber membrane filter cartridge, and more particularly to an exchangeable hollow fiber membrane filter cartridge suitable for mounting in a commercially available standard filter housing. Specific application fields of this filter cartridge include ultrapure water filtration in semiconductor production, aseptic filtration in pharmaceuticals, aseptic filtration and concentration for food and beverage applications, and air filters.

[0002]

2. Description of the Prior Art Filter housings are typically standardized to accommodate cylindrical cartridges about 3 inches in diameter and 8 to 12.6 inches (typically 10 inches) in length. Many of such filter cartridges have a structure in which a flat membrane is used as a filtering member, which is folded in a pleated shape and inserted into a cylinder. The pleated flat membrane module is used for various applications, and particularly for the production of ultrapure water in the semiconductor industry where extremely high purity and flow rate are required.

Recently, a module using a hollow fiber membrane having a much larger membrane area than a module using a flat membrane as a filtration member has been marketed, and such a module has a very high particle removal efficiency. It has the advantages of high cost, long service life, and high flow rate.
No. 05).

[0004]

At present, a commercially available standard type filter cartridge (module) using a hollow fiber membrane has a hollow fiber membrane inserted into a cylindrical case having an outer diameter of about 3 inches in parallel with its longitudinal direction. Then, one end or both ends of the hollow fiber membrane are sealed with a resin at the end of the cylinder, so-called potting is performed, and the hollow portion of the hollow fiber membrane is kept open at the end by cutting off the resin-fixed portion. 1.75 inches (4.44c) that fits into the housing
m) or a pipe-like coupling member having an outer diameter of 2.25 inches (5.71 cm) or the like is attached to the cylindrical case so as to cap the open end of the hollow fiber membrane.

[0005] Such a hollow fiber membrane module has a large membrane area as compared with a flat membrane. When a liquid such as water is filtered using this module, a flow rate corresponding to the increase in the membrane area is obtained. The inability to get it often happened. This is due to the resistance generated when the filtered liquid flows through the hollow portion (in the tube) of the hollow fiber membrane. Several hundred μm inside diameter
When a normal hollow fiber membrane of about 1 mm is used and the length of the hollow fiber membrane is about 20 cm of the length of the standard type filter cartridge (when the total length of the cartridge is about 10 inches),
Such tube resistance cannot be ignored. In particular, the higher the flow rate of the membrane itself, the greater the resistance in the tube.

[0006] Standard filter cartridges having a filter cartridge length of 20 inches or 30 inches are also commercially available to process a larger amount of liquid. In the case of a flat membrane, the flow rate is increased by an amount corresponding to the increased membrane area. Can be secured. However, in the case of the hollow fiber membrane, the internal resistance increases as the length of the hollow fiber membrane increases, and a sufficient flow rate according to the membrane area cannot be obtained. In other words, in order to obtain a flow rate equivalent to that of a flat membrane cartridge of the same size, there is a problem that it is necessary to apply several times the pressure.

At the same time as the above-mentioned problem, due to the resistance of the hollow fiber membrane in the tube, the membrane surface near the resin is mainly used for filtration, and the distal end, that is, the portion far from the resin-fixed portion is used. It is also difficult to use the membrane surface.
For this reason, there is also a problem that the film surface near the resin fixing portion is rapidly clogged, and a sudden increase in the differential pressure is caused, thereby shortening the life of the module.

In order to obtain a high flow rate, a method of increasing the number of hollow fiber membranes to increase the membrane area, that is, a method of increasing the filling rate can be considered, but the number of hollow fiber membranes that can be accommodated in the case is limited. Further, if the filling rate is too high, the hollow fiber membranes are likely to adhere to each other via the deposits, and it is difficult to effectively use the hollow fiber membrane at the center of the module.

An object of the present invention is to provide a hollow fiber membrane filter cartridge capable of reducing the in-tube resistance of a hollow fiber membrane, obtaining a flow rate corresponding to the membrane area, and effectively utilizing the entire installed membrane. It is in.

[0010]

That is, the present invention relates to a hollow fiber membrane filter cartridge comprising a hollow fiber membrane provided in a cylindrical case having a coupling means at one end thereof in parallel with a longitudinal direction thereof. At both ends of the cylindrical case,
A water collecting chamber for collecting the treatment liquid permeated through the hollow fiber membrane is provided, and a water collecting pipe connecting the two water collecting chambers is provided. A hollow fiber membrane filter cartridge which is provided in a cylindrical case.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view of the hollow fiber membrane filter cartridge of the present invention. In this hollow fiber membrane filter cartridge, the hollow fiber membrane 1 is disposed in the cylindrical case 2 in parallel with the longitudinal direction thereof, and both ends thereof are fixed by the fixing members 3, 3 'while maintaining the open state. I have. In addition, one water collecting pipe 4 is disposed at the center of the cylindrical case in parallel with the hollow fiber membrane, and both ends thereof are fixed by both fixing members. At both ends of the cylindrical case, water collecting chambers 5 and 5 'for collecting the treated water that has passed through the hollow fiber membrane are arranged in a liquid-tight manner with the liquid to be treated by a fixing member. At one end of the cylindrical case, there is provided a cylindrical outlet port 6 for treated water, which also functions as a coupling means 7 with the filter housing, and an O-ring 8 is attached to the outer periphery thereof. .

As the hollow fiber membrane 1 used in the hollow fiber membrane filter cartridge of the present invention, for example, those made of various materials such as cellulose, polyolefin, polyvinyl alcohol, and polysulfone can be used. The pore diameter, porosity, film thickness, outer diameter, etc. are not particularly limited as long as they can be used as a filtration membrane, but should be 0.2 μm or less for the purpose of removing bacteria. Is required,
For the purpose of removing organic substances and viruses, it is necessary to use an ultrafiltration membrane having a molecular weight cutoff of tens of thousands to hundreds of thousands.

For the purpose of filtering an organic solvent or the like, the surface characteristics of the hollow fiber membrane may be hydrophobic. However, when filtering an aqueous liquid, the surface characteristics of the hollow fiber membrane are hydrophilic. Preferably, there is. Further, a so-called permanent hydrophilized membrane having a hydrophilic group or the like on the surface of the hollow fiber membrane is more preferable.

As the method for producing the permanent hydrophilic membrane, a known method such as a method for producing a hollow fiber membrane with a hydrophilic polymer such as a polyvinyl alcohol type or a method for hydrophilizing the surface of a hydrophilic polymer membrane is used. it can. For example, examples of the hydrophilic polymer for imparting a hydrophilic polymer to the membrane surface to hydrophilize the hydrophobic hollow fiber membrane include saponified ethylene-vinyl acetate copolymers and polyvinylpyrrolidone. .
As another method, a method of spinning and forming a film by blending a hydrophilic polymer with a hydrophobic polymer (for example, polyolefin or polysulfone) can be mentioned, and examples of the hydrophilic polymer to be used are described above. Things.

If the surface of the hollow fiber membrane is hydrophobic, hydrophobic interaction between organic matter in the water to be treated and the surface of the hollow fiber membrane occurs, and organic substances are adsorbed on the membrane surface, which causes blockage of the membrane surface. And the filtration life is shortened. By using the permanent hydrophilizing membrane, the hydrophobic interaction between the organic substance and the surface of the hollow fiber membrane can be reduced, and the adsorption of the organic substance can be suppressed. When the membrane is dried and becomes hydrophobic, the flux may be reduced. However, the permanent hydrophilized membrane does not cause the flux to be reduced even when dried. The cylindrical case 2 functions as a member for supporting the entire hollow fiber membrane filter cartridge, and at the same time, has an outer diameter at one end adapted to the concave-shaped coupling portion of a commercially available standard type filter housing. A coupling means 7 is provided, and can be connected to the filter housing in a liquid-tight or air-tight manner via an O-ring 8 provided on the outer periphery thereof. The cylindrical case may be integrally formed up to the coupling joint, or the cylindrical joint may be formed separately and adhered to the end of the case. Further, an opening (slit) is provided on the side of the cylindrical case where the hollow fiber is exposed so that the treatment liquid enters the cylindrical case and is filtered by the hollow fiber membrane.

It is preferable that the dimensions of the entire filter cartridge conform to those of a commercially available filter cartridge. Typical dimensions are about 10 inches (2 inches) in total length.
5.4 cm), the outer diameter of the place where the hollow fiber membrane is housed is about 3 inches (7.62 cm), and the outer diameter of the part which is coupled to the filter housing as the coupling means is about 1.7.
5 inches (4.44 cm). The length of the cylindrical case may be as long as 20 inches or 30 inches, or may be as short as about 3 inches.

The material of the cylindrical case 2 may be any material having mechanical strength and durability. For example, polycarbonate, polysulfone, polyethylene, polypropylene, acrylic resin, ABS resin, polyacetal resin,
Examples thereof include polyphenylene oxide-based resins and fluorine-based resins.

The fixing members 3, 3 'bundle the hollow fiber membrane 1,
It is a member to be fixed, while fixing in the cylindrical case while maintaining its open state at both ends of the hollow fiber membrane,
It functions as a member that partitions the liquid to be treated and the treatment liquid in a liquid-tight manner and forms a water collecting chamber. The fixing member is usually obtained by curing a liquid resin such as an epoxy resin, an unsaturated polyester resin, or a polyurethane resin.

The water collecting pipe 4 is a pipe for sending the processing liquid collected in the water collecting chamber 5 'on the side where the coupling means is not provided to the other water collecting chamber 5, and has a cylindrical case. And fixed by a fixing member like a hollow fiber membrane. In FIG. 1, only one water collecting pipe 4 is provided, but a plurality of water collecting pipes 4 may be provided. The water collecting pipe 4 can be arranged in a cylindrical case, is thicker than the inner diameter of the hollow fiber membrane, and can be negligible in pressure loss when sending the processing liquid.
The inner diameter and outer diameter are not particularly limited. The material of the water collecting pipe 4 is similar to that of the cylindrical case 2.

As the coupling means 7, when the filter cartridge is mounted on the filter housing,
Any material may be used as long as it is completely sealed, but it is preferable to use a member having an O-ring 8 provided on the outer periphery of a cylindrical member thinner than the cylindrical case 2. The diameter of the concave part in the coupling connection of the standard filter housing is 1.00 inch (2.54 cm), 1.
75 inches (4.44 cm), 2.25 inches (5.7
1 cm) and the like are typical. Therefore, O-rings suitable for these apertures, ie, -020 type, -222
Type and -226 type are preferable. The material of the O-ring may be any.

[0022]

EXAMPLES The present invention will be specifically described by way of examples.

Example 1 A cylindrical polycarbonate case having a slit of 21.5 cm in length and an inner diameter of 6.4 cm and a water collecting pipe made of a polycarbonate having an outer diameter of 2.86 cm and an inner diameter of 2.56 cm was mainly placed. Then, a material covered with a polyethylene hollow fiber membrane (outside diameter: 380 μm, inside diameter: 270 μm) was inserted, and both ends were fixed with urethane resin while holding the opening at the end face of the hollow fiber membrane. Next, a coupling coupling member is attached to one end of the cylindrical case, and a -222 type O
Two rings were attached. A cap was attached to the other end so as to partition the liquid to be treated in a liquid-tight manner, and a 10-inch hollow fiber membrane filter cartridge having a longitudinal section as shown in FIG. 1 was produced.

The length of the hollow fiber membrane exposed on the side of the liquid to be treated is 18.5 cm, and the number of filled hollow fiber membranes is 97
The number of the membranes was 60, the effective membrane area was 2.16 m ² , and the filling rate of the hollow fiber membrane at the hollow fiber membrane filling portion in the cylindrical case was 43%.

Using this hollow fiber membrane filter cartridge, pure water was filtered at a differential pressure of 0.5 kg / cm ² , and the flow rate at that time was measured. The results are shown in Table 1.

Comparative Example 1 Except that the hollow fiber membrane was looped into a U-shape and converged after being inserted into a cylindrical case, and the end was fixed with urethane resin while holding the opening at the end face of the hollow fiber membrane. Example 1
A conventional hollow fiber membrane filter cartridge was produced in the same manner as described above.

The exposed fiber length of the hollow fiber membrane of this cartridge is 20 cm, the number of filled hollow fiber membranes is 12200 (number of loops: 6100), the effective membrane area is 2.91 m ² , and the filling rate of the hollow fiber membrane is 43%. there were. Table 1 shows the results of measuring the filtration flow rate in the same manner as in Example 1.

Example 2 The materials of the housing case and the water collecting pipe were polysulfone,
The material of the hollow fiber membrane is a mixture of polyethersulfone and polyarylsulfone (outside diameter: 590 μm, inside diameter: 405 μm)
m) A hollow fiber membrane filter cartridge was produced in the same manner as in Example 1, except that the fixing member was changed to an epoxy resin.

The exposed fiber length of the hollow fiber membrane of this cartridge was 18.5 cm, the number of filled hollow fiber membranes was 4050, the effective membrane area was 1.39 m ² , and the filling rate of the hollow fiber membrane was 43%. Table 1 shows the results of measuring the filtration flow rate in the same manner as in Example 1.

Comparative Example 2 A comparison was made except that the material of the housing case was polysulfone, the material of the hollow fiber membrane was a mixture of polyethersulfone and polyarylsulfone (590 μm in outer diameter, 405 μm in inner diameter), and the fixing member was epoxy resin. A hollow fiber membrane filter cartridge was produced in the same manner as in Example 1.

The exposed length of the hollow fiber membrane of this cartridge is 20 cm, and the number of filled hollow fiber membranes is 5060 (number of loops:
2530), and the effective membrane area was 1.88 m ² . Table 1 shows the results of measuring the filtration flow rate in the same manner as in Example 1.

Example 3 A hollow fiber membrane filter cartridge was prepared in the same manner as in Example 2 except that the length of the housing case was 65 cm, the exposed length of the hollow fiber membrane was 61 cm, and the effective membrane area was 4.58 m ^2. Was prepared. Table 1 shows the results of measuring the filtration flow rate in the same manner as in Example 1.

Comparative Example 3 A hollow fiber membrane filter cartridge was prepared in the same manner as in Comparative Example 2 except that the length of the housing case was 65 cm, the exposed fiber length of the hollow fiber membrane was 63 cm, and the effective membrane area was 5.91 m ^2. Was prepared. Table 1 shows the results of measuring the filtration flow rate in the same manner as in Example 1.

[0034]

[Table 1] In comparison with the filter cartridge of 10 inch size, in the case of the same hollow fiber membrane filling rate (43%), there was almost no difference in flow rate per cartridge, but considering the difference in membrane area, the filter cartridge of the present invention was It can be seen that filtration is performed efficiently using the membrane surface. Further, when the length of the cartridge was increased to 30 inches, a high flow rate was obtained with the filter cartridge of the present invention despite the smaller membrane area.

[0035]

The hollow fiber membrane filter cartridge of the present invention has the same size and shape as a conventional standard filter cartridge utilizing a hollow fiber membrane, but can obtain a high flow rate with a smaller membrane area than conventional products. In addition, since the entire surface of the hollow fiber membrane can be effectively used, an increase in differential pressure due to local clogging is unlikely to occur.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a hollow fiber membrane filter cartridge of the present invention.

[Explanation of symbols]

 Reference Signs List 1 hollow fiber membrane 2 cylindrical case 3, 3 'fixing member 4 water collecting pipe 5, 5' water collecting chamber 6 treated water outlet 7 coupling means 8 O-ring

Claims (1)

[Claims] 1. A hollow fiber membrane filter cartridge in which a hollow fiber membrane is provided in a cylindrical case having a coupling means at one end thereof in parallel with a longitudinal direction thereof, and a hollow fiber membrane is provided at both ends of the cylindrical case. A water collecting chamber is provided for collecting the processing liquid permeated through the hollow fiber membrane, which is separated by a fixing member that fixes the ends while maintaining the open state, and a water collecting pipe connecting the two water collecting chambers is provided in the cylindrical case. A hollow fiber membrane filter cartridge, which is provided.