JPH06182160A - Hollow yarn-type cartridge filter - Google Patents

Abstract

PURPOSE:To provide a hollow yarn-type cartridge filter for liquid gas filtration using a hollow yarn membrane. CONSTITUTION:The hollow yarn-type cartridge filter consists of water-permeable yarns 5, folded back in a loop form, which are filled in a space between a porous outer cylinder 2 and a poreless inner cylinder 1 arranged almost concentrically with a poreless bottom 3 excepting an inner cylindrical part 8 in which said yarn 5 is not present. In addition, the other end of the folded back part of the yarns 5 are cohesively bundled together with the inner cylinder, the outer cylinder and a potting material 6 so that an opening is formed on the other end. Further, a cap 4 having a liquid passage 9 connecting between the opening and the outer cylinder, to the outer cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cartridge filter for filtering liquid or gas, which uses a hollow fiber membrane.

[0002]

2. Description of the Related Art As a cartridge filter for fluid filtration, a so-called pleated type cartridge filter in which a film-like membrane having a large number of folds is filled in a space between double perforated cylinders has been mainly used. In order to further increase the speed and enable backwashing, a hollow fiber membrane has been developed instead of the pleated membrane.

Since the pleated cartridge filter has a unified design so that the products of each company can be replaced, it is desirable that the pleated cartridge filter can be interchanged in the same manner even when a hollow fiber membrane is used, and various contrivances have been made conventionally. Came.

For example, in Japanese Patent Laid-Open No. 62-74408, a non-perforated inner cylinder is used in place of the perforated inner cylinder of a pleat type cartridge filter, and a hollow fiber is filled in a space between the perforated outer cylinder. Then, a cartridge filter is described which is compatible with a pleated cartridge filter in which caps having fluid passages to the outside are connected to the upper and lower ends, respectively, by concentrating them with potting materials so that hollow fibers are opened at the upper and lower ends.

Further, in Japanese Patent Laid-Open No. 64-30605, only a perforated outer cylinder of a pleated cartridge filter is used, and hollow fibers are filled in the outer cylinder to seal one end with a potting material and the other end. It is described that the outer cylinder and the potting material are focused and fixed so that the hollow fibers are opened, and then a cap having a fluid passage to the outside is connected to be compatible with a pleated cartridge filter.

Further, as shown in FIG. 4, a hole 10 is formed on the outer peripheral surface.
, A plurality of hollow fibers 102, ... Are arranged in the cylindrical body 100 having 1 and are focused and fixed to the ends of the cylindrical body 100 by potting materials 103 and 103 so that both ends thereof are opened. Fluid passages 10 at both ends of 100
There is also a structure in which the caps 104 having 104 and 104 are hermetically connected.

However, these hollow fiber type cartridge filters cannot necessarily be said to have sufficiently satisfied the advantages of the hollow fibers and the compatibility with the pleated type cartridge filter.

[0008]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention JP-A-62-7
According to Japanese Patent No. 4408, the filtration rate is not high because the filling volume of the hollow fiber is sacrificed so much as to resemble the design of a pleated cartridge filter. on the other hand,
In JP-A-64-30605, the inner cylinder is removed so much that the filling amount of the hollow fiber is increased, so that it cannot be applied to a housing in which a bolt for fixing a cartridge filter is inserted into the inner cylinder.

It is an object of the present invention to provide a hollow fiber type cartridge filter which eliminates these drawbacks and is compatible with all pleated type cartridge filters without sacrificing the characteristics of the hollow fiber.

[0010]

In the pleat type cartridge filter, the inner diameter of the outer cylinder is almost double the outer diameter of the inner cylinder in order to maximize the storage area of the pleat membrane. From the viewpoint of fluid pressure loss and fixing bolts, the diameter of this inner cylinder is too large. In order to increase the filling volume of the hollow fiber as much as possible, it is necessary to reduce the volume loss due to the potting material as much as possible.

The present inventor has arrived at the present invention as a result of extensive studies from such a viewpoint in order to solve the above problems. That is, according to the present invention, a plurality of water-permeable hollow fibers folded back in a loop shape are arranged so as to be substantially concentric with a non-perforated bottom except for the inner cylindrical portion and a non-perforated outer cylinder. A cap that is filled in the space between the cylinders and focused and fixed to the inner cylinder and the outer cylinder with a potting material so that the other end of the folded portion of the hollow fiber is opened, and has a fluid passage between these openings and the outside. Is connected to the outer cylinder, and more preferably, the outer diameter of the inner cylinder is made 1/5 to 1/3 of the inner diameter of the outer cylinder.

[0012]

According to the present invention, the filling volume of the hollow fiber by the inner cylinder is reduced by narrowing the outer diameter of the inner cylinder within the range where the cartridge filter fixing bolt passes and the pressure loss of the fluid does not become excessive. It is supplemented by gathering and fixing both ends of the thread folded back into a loop on one side and focusing and fixing only the open end with a potting material, and since it has an inner cylinder, it is not only compatible with any pleated type but this It is also possible to connect a plurality of cartridges in series. The hollow fiber type cartridge filter of the present invention is not only compatible with all conventional pleated type cartridge filters, but also has a higher filtration rate than the pleated type cartridge filter and can be backwashed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view showing an embodiment of the structure of the hollow fiber type cartridge filter of the present invention in order to specifically describe it. The schematic structure is a non-perforated inner cylinder 1
Are arranged substantially concentrically inside the perforated outer cylinder 2, one end of the inner cylinder 1 is fixed to the bottom 3 of the outer cylinder 2, and a cap 4 is connected to the open end of the outer cylinder 2 in a sealed state. In addition, inner cylinder 1 and outer cylinder 2
A plurality of water-permeable hollow fibers 5, the central portion of which is folded back in a loop shape (or U-shape), are arranged between them, and both ends thereof are gathered on one side and the outer end together with the open end of the inner cylinder 1. The tube 2 is focused and fixed by the potting material 6 on the open end side.

More specifically, as shown in FIGS. 1 and 2, a plurality of water permeable hollow fibers 5 are housed in the space between the non-perforated inner cylinder 1 and the outer cylinder 2 having the hole 7 on the outer peripheral surface. ing. The non-perforated inner cylinder 1 and the perforated outer cylinder 2 are arranged substantially concentrically, and the outer cylinder 2 has a non-perforated bottom 3 except for an inner cylinder portion 8 communicating with the inner cylinder 1. The hollow fiber 5 is folded back in a loop shape near the bottom 3,
The other end is focused and fixed by the outer cylinder 2 and the potting material 6 together with the inner cylinder 1 so that the end is opened. A cap 4 having fluid passages 9 between these openings and the outside is connected to the outer cylinder 2. That is, the inside of the inner cylinder 1 and the inner cylinder portion 8
It also penetrates linearly with the fluid passage 9 and can be attached to the housing with a bolt described later.

The outer diameter of the inner cylinder 1 should be such that the inner diameter thereof passes through the cartridge fixing bolt and does not cause excessive pressure loss of the fluid, and is preferably 1/5 to 1/3 of the inner diameter of the outer cylinder. Usually, a plastic material such as polyvinyl chloride, polycarbonate, polypropylene, polysulfone, and ABS resin is used for the inner cylinder 1, the outer cylinder 2, and the bottom 3, but they may be integrally molded products, such as ultrasonic welding. You may adhere with.

A large number of hollow fibers 5 are filled so that the total outer diameter cross-sectional area of the hollow fibers is 40 to 60% of the cross-sectional area perpendicular to the cylindrical axis of the space between the inner cylinder 1 and the outer cylinder 2. Has been done. The end of the hollow fiber is an epoxy resin,
A potting material 6 such as urethane resin or silicone resin is focused and fixed together with the inner cylinder and the outer cylinder so that the hollow fiber end and the inner cylinder end are opened.

The cap 4 having the fluid passage 9 communicating with the outside is connected at the end of the outer cylinder 2 by means such as adhesion, screwing or welding. In the case of screw-type connection, the cap 4 may be not only a gasket that seals the fluid but also an O-ring (neither is shown).

FIG. 3 is a schematic view showing an embodiment in which a plurality of hollow fiber cartridge filters 10 of FIG. 1 are connected in series and arranged in a housing 11 for use. The hollow fiber cartridge filter 10 has an inlet 13 and an outlet 14.
Three of them are arranged in series in the housing 11 having the above through the gasket 12 and are fixed by the bolts 15 passing through the inner cylinder 1. The treatment fluid is sent from the inlet 13 into the housing 11, and is filtered from the outside of the hollow fiber 5 through the hole 7 of the outer cylinder 2 of the hollow fiber cartridge filter 10. The filtered fluid passes through the inside of the hollow fiber 5 and is collected in the collecting chamber 16 formed by the cap 4 and the potting material 6, and the fluid passage 9 and the inner cylinder 1 are provided in the upper cartridge filter.
Sent through. The filtered fluid passage 9 of the uppermost cartridge filter is connected to the filtered fluid outlet 14 of the housing.

The hollow fiber 5 must withstand not only the filtration pressure but also the vibration and tensile load applied to the hollow fiber when a large amount of fluid is filtered. Therefore, the tensile strength per hollow fiber needs to be 100 g or more, more preferably 150 g or more. The maximum elongation is required to be 20%, more preferably 30% or more.

Since the hollow fiber type cartridge filter is mainly used for filtering water or an aqueous solution, it is important that the properties of the hollow fiber are properly designed in such a field. It is possible to analytically set the inner diameter that maximizes the water permeation rate of the cartridge filter while maintaining the strength of the hollow fiber. If the hollow fiber is made thin, the effective filtration area of the hollow fiber that can be stored can be increased, but when water is filtered from the outside of the hollow fiber, the filtered water that flows inside the hollow fiber can be used in the same way as a normal pleated cartridge filter. Pressure loss increases. Therefore, there is an optimum value of the dimension of the hollow fiber which maximizes the water permeation rate as a cartridge filter corresponding to the water permeability coefficient of the hollow fiber.

For example, the water permeability coefficient of the hollow fiber is 1000,
In the case of 5000 and 10000 l / m ² · hr · Kg / cm ² , the water permeation rate when using a cartridge filter depends on the wall thickness of the hollow fiber required to maintain strength, but it is about 300 μm each. , 400 μm and 500
Maximum when μm. At this time, the water permeation rate as a standard size cartridge filter corresponding to the pleated type cartridge filter is about 4, 11, and 17 l / min at a filtration pressure of 0.1 kg / cm ² . When the hollow fiber is longer than this standard size, the water permeation rate is not proportional to the effective area because the pressure loss of the filtered water increases. Therefore, when filtering a large amount, connecting a standard-size cartridge with a filtered water passage in the inner cylinder in series as shown in Fig. 1 should increase the filtration speed rather than lengthening the hollow fiber. You can However, if the water permeability coefficient of the hollow fiber is less than 1000 l / m ² · hr · Kg / cm ² , the contribution of the pressure loss of the filtered water becomes small and the effective area becomes large even if the hollow fiber is longer than the standard size. It is advantageous to store as many hollow fibers as possible. Therefore, the water permeability coefficient of the hollow fiber used in the present invention is 100.
It is preferably 0 l / m ² · hr · Kg / cm ² or more.

As such hollow fibers, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, cellulose acetate, regenerated cellulose,
Those made of various materials such as polysulfone can be used. Of these, polysulfone is particularly preferable because it has not only a higher water permeation rate than other materials but also excellent properties such as strength and heat resistance.

The present invention will be described in more detail below.

Hollow fibers 2-3 having a folded length of about 10 cm
Book, inner diameter, outer diameter, length 6mm, 8mm, 15cm respectively
It was put in the glass tube of No. 1 and the end of the hollow fiber was opened so as to be focused and fixed with urethane resin to prepare a mini-filter. Using this mini filter, the filtration rate of water is measured while changing the filtration pressure from the outside of the hollow fiber, and the measured value at each pressure is expressed in units of l / m ² · hr · Kg / cm ² and the filtration pressure is 0. The value when extrapolated to was taken as the water permeability coefficient. The water used is
Temperature 2 when filtered with an ultrafiltration membrane with a molecular weight cut-off of about 60,000
It is tap water at 5 to 30 ° C.

(Example 1) The inner dimensions are 22 cm in length and 6 in inner diameter.
A space between a 1 mm outer cylinder with a hole and an inner cylinder with an outer diameter of 20 mm and an inner diameter of 16 mm was bent into a loop and had a water permeability coefficient of 6
600 l / m ² · hr · Kg / cm ² and 1400 hollow fibers made of polysulfone having inner and outer diameters of 500 μm and 800 μm and having a logarithmic removal rate of 0.1 μm of polymer particles of 5 or more are filled. As shown in FIG. 1, the end portion was converged and fixed with a urethane resin so that the inner cylinder and the tip of the hollow fiber were opened. A 2.5 cm long cap was adhered to this to prepare a hollow fiber type cartridge filter having a total length of 25 cm. The average length of the potting material was 15 mm, the average effective length of the hollow fiber to the tip of the unpotted loop was 19 cm, and the effective membrane area was 1.3 m ² .
When this cartridge filter was set in a housing for a commercially available pleated cartridge filter and the filtration rate of water was measured, the filtration pressure was 0.1 Kg / cm ²
It was l / min.

(Embodiment 2) A hollow fiber storage case consisting of the same inner and outer cylinders as in Embodiment 1 was bent into a loop,
Water permeability coefficient is 9000 l / m ² · hr · Kg / cm ² , log removal rate of Pseudomonas bacteria is 7 or more, inner and outer diameter is 600
1150 μm and 900 μm polysulfone hollow fibers
After full filling, the effective membrane area was 1.2 m ² as in Example 1.
A hollow fiber type cartridge filter was prepared. The filtration rate of this cartridge filter was 17 l / min at a filtration pressure of 0.1 Kg / cm ² .

(Example 3) Water permeation coefficient of 3300 l / m ²
-Hr · Kg / cm ² , 0.04μm polymer particles with a logarithmic removal rate of 5 or more, inner and outer diameters of 500μm and 800μ
A cartridge filter was prepared in the same manner as in Example 1 except that the polysulfone hollow fiber of m was used, and the filtration rate was measured and found to be 8 l / min at a filtration pressure of 0.1 Kg / cm ² .

The hollow fiber type cartridge filters of Examples 1 to 3 each had a filtration rate of 1.5 to 4 times that of the pleated type cartridge filters corresponding to the removal particle size.

(Examples 4 to 6) Two of the cartridge filters prepared in Examples 1, 2 and 3 were connected in series as shown in FIG. 3 and fixed with bolts having an outer diameter of 8 mm.
The filtration rates of these filters were 28, 32 and 16 l / min respectively at a filtration pressure of 0.1 kg / cm ² .

Example 7 Using the filter of Example 1, an aqueous solution in which powdered talc was dispersed was filtered until the filtration rate became half of the initial value, and then the filtrate was flowed in reverse to the outer surface of the hollow fiber. The accumulated talc powder was removed by backwashing. When the talc dispersion was filtered again, the initial initial value was restored. Even when this cycle was repeated 10 times, the filtration rate was recovered similarly.

(Comparative Example 1) 3200 hollow fibers same as those in Example 1 were filled only in a perforated outer cylinder having an inner diameter of 61 mm and a length of 45 cm, and both ends were opened so that the hollow fiber ends were open. Focused and fixed together with the tube. The length of the potting portion was 15 mm at both ends, the effective length of the hollow fiber was 42 cm, and the effective membrane area was 3.4 m ² . 2.5 cm long caps were adhered to both ends to prepare a cartridge filter having a total length of 50 cm. The filtration rate of this filter was 20 l / min at a filtration pressure of 0.1 Kg / cm ² . Compared with Example 4, it can be seen that the pressure loss of the filtrate flowing inside the hollow fiber becomes predominant when the hollow fiber becomes long because the filtration rate is low despite the large effective membrane area.

[0032]

The hollow fiber type cartridge filter of the present invention has the features of the hollow fiber that can be backwashed and has a high filtration rate and the feature that it is compatible with the conventional pleated type cartridge filter, and its economic effect is Is large.

[Brief description of drawings]

FIG. 1 is a simplified cross-sectional view showing a hollow fiber cartridge filter of the present invention.

FIG. 2 is an enlarged cross-sectional view of the same with a part omitted.

FIG. 3 is a simplified cross-sectional view showing a case where three cartridge filters of the present invention are connected in series to a conventional pleated cartridge filter housing and used.

FIG. 4 is a simplified cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Inner Cylinder 2 Outer Cylinder 3 Bottom 4 Cap 5 Hollow Fiber 6 Potting Material 7 Hole 8 Inner Cylinder Part 9 Fluid Passage 10 Hollow Fiber Cartridge Filter 11 Housing 12 Gasket 13 Inlet 14 Outlet 15 Bolt 16 Assembly Room

Claims (5)

[Claims] 1. A perforated outer cylinder and a non-perforated inner cylinder arranged so that a plurality of water-permeable hollow fibers folded back in a loop shape are substantially concentric with each other except for the inner cylinder portion and having a non-perforated bottom. Space between the inner cylinder and the outer cylinder so that the other end of the folded portion of the hollow fiber is opened, and is fixed by a potting material, and a cap having a fluid passage between these openings and the outside is provided. A hollow fiber cartridge filter connected to the outer cylinder. 2. The outer diameter of the inner cylinder is 1/5 to 1 / of the inner diameter of the outer cylinder.
3. The hollow fiber type cartridge filter according to claim 1, which is 3. 3. The hollow fiber type cartridge filter according to claim 1, wherein the hollow fiber has a tensile strength of 100 g / strand or more and an elongation of 20% or more. 4. The hollow fiber type cartridge filter according to claim 1, wherein the hollow fiber has a water permeability coefficient of 1000 l / m ² · hr · Kg / cm ² or more. 5. The hollow fiber type cartridge filter according to claim 1, wherein the hollow fiber is polysulfone.