JPH0711784Y2 - filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a filter using a hollow fiber membrane bundle.

<Prior Art> There is a case where a tap filter is equipped with a full-filter cartridge filter to filter tap water before use. Recently, it has been proposed to use an ultrafiltration membrane or a microfiltration membrane for this type of filter, and in particular, a cartridge filter using a hollow fiber membrane capable of taking a large membrane area per unit volume has been receiving attention. . FIG. 4 shows a hollow fiber membrane cartridge of this kind prototyped by the inventors of the present invention, in which a hollow fiber membrane bundle 1'for embedding and sealing one end in a plate-shaped resin block 2'is provided in an outer cylinder 3 '. And the other end of the hollow fiber membrane bundle is opened to the outside of the system from one end of the jacket cylinder through the resin partition wall 4 '.

The attachment to the water supply currant is performed at the other end of the envelope. Thus, when the currant is put into a water-passing state, the raw water is pressurized and supplied into the outer casing from between the plate-shaped resin block and the other end of the outer casing, and microorganisms in the raw water are blocked by the hollow fiber membrane. ,
The clean water that has permeated the hollow fiber membrane is taken out as water from the one end opening of the fiber membrane.

<Problems to be Solved> However, in this hollow fiber membrane cartridge,
When pressurizing and pouring raw water into the envelope cylinder, the hollow fiber membrane bundle is tightened from the outer periphery and becomes dense, and the flow resistance when sewing the gap between the hollow fiber membranes becomes large. It is difficult to supply raw water to the central part, and it is difficult to obtain a predetermined amount of permeated water. However, as time passes, the central part of the hollow fiber membrane bundle also comes into contact with the raw water pressure, and the hollow fiber membrane returns to its initial position due to its bending rigidity, and a gap is maintained between the hollow fiber membranes, and Although the amount of permeated water can be obtained, it takes a long time to reach such a normal state as the hollow fiber membrane becomes extremely fine, that is, as the bending rigidity becomes low,
In particular, this is a problem when the membrane filling efficiency is improved by using an ultrafine hollow fiber membrane.

An object of the present invention is to provide a hollow fiber membrane cartridge which can secure a sufficient gap passage between the hollow fiber membranes from the beginning of supplying pressurized raw water.

<Means for Solving the Problems> In the filter according to the present invention, a hollow fiber membrane bundle is housed in an outer cylinder, one end of the hollow fiber membrane is opened outside the outer cylinder through a resin partition wall, and a passage hole is formed in the center. And the gap between the outer cylinder and
The other end of the hollow fiber membrane bundle is embedded in a plate-shaped resin block of 1.0 mm or less, and a conical passage is formed in the hollow fiber membrane bundle from the passage hole of the block toward the resin partition wall. , Same as above, the inner diameter of the passage hole of the block is
The configuration is characterized by being set to 0.4 to 0.6 times.

<Description of Embodiments> Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. In FIGS. 1 and 2, 1 is a hollow fiber membrane bundle, and one end of each fiber membrane is an open end. 2 is a plate-shaped resin block cast on the other end of the hollow fiber membrane bundle, and the other end of each hollow fiber membrane is closed by embedding in the block. 20 is a passage hole provided in the center of the block. Reference numeral 3 denotes an outer cylinder, in which the hollow fiber membrane bundle is housed. The gap g between the jacket cylinder and the block is set to 1.0 mm or less in order to make the inflow of raw water from this gap substantially zero. Reference numeral 4 denotes a resin partition wall cast into one end of the outer cylinder, and one end of the hollow fiber membrane bundle penetrates the resin partition wall and is opened outside the outer cylinder. Reference numeral 5 denotes a conical passage formed in the hollow fiber membrane bundle, which is narrowed from the passage hole of the plate-shaped resin block to the resin partition wall. The inlet diameter of this conical passage, that is, the passage hole diameter r ₀ of the plate-shaped resin block is 0.4 to 0.6 of the block outer diameter.
Is doubled.

As the above hollow fiber membranes, polyethylene, polypropylene, polycarbonate, polyacrylonitrile, polysulfone, polyester, polymethylmethacrylate, polyamide, ultrafiltration hollow fiber membranes made of cellulose triacetate, microfiltration hollow fiber membranes and the like can be used. Further, epoxy resin, urethane resin, or silicon resin can be used for the plate-shaped resin block and the resin partition. Also,
The outer cylinder can be made of plastic or metal. Further, a transparent transparent plastic tube can be used.

The filter according to the present invention is used in a state in which the other end of the jacket cylinder is attached to the water supply currant. Thus, when the tap water is used, the raw water is pressed into the conical hole passage in the hollow fiber membrane bundle through the passage hole of the plate-shaped resin block, and the hollow fiber membrane bundle is expanded for pressurization from the conical hole passage. . The expansion of the hollow fiber membrane bundle is a result of each hollow fiber membrane being flexibly deformed due to water flow pressure (equally distributed load). When the hollow fiber membrane at the innermost circumference is projected on the hollow membrane at the outermost circumference, both are the same in span length, load distribution, and support state, so the radial change of the outermost circumference fiber membrane at the same position (filter). The change in the direction perpendicular to the axial direction) dR is equal to the change in the radial direction dr of the innermost thread film.

Therefore, the cross-sectional area S of the hollow fiber membrane bundle at a certain position is S = π (R ² −r ² ) −, and the allocated space α per hollow fiber membrane is S / N (N
Is the number of fiber membranes), and the change in α with the expansion of the hollow fiber membrane bundle Δα is And, because dR = dr, Becomes

This Δα evaluates the increase in the gap between the hollow fiber membranes due to the expansion of the bundle of hollow fiber membranes, and the larger Δα, the larger the gap between the hollow fiber membranes, so that raw water can be supplied with low resistance. is there. However, as is clear from the equation, the larger r becomes, the smaller Δα becomes, which acts to hinder the low resistance supply. However, in the present invention, the passage hole diameter of the plate-shaped resin block is set to the block outer diameter, that is,
Since the outer diameter of the hollow fiber membrane bundle is limited to 0.6 times or less, Δα can be made sufficiently large for the entire hollow fiber membrane bundle, and low resistance supply is possible. Moreover, since the diameter of the passage is the same as the outside diameter of 0.4 times or more, the resistance in the conical passage can be reduced,
The supply resistance of the entire filter can be made sufficiently low.

FIG. 3 shows another embodiment of the present invention in which a reinforcing net 6 is provided on the outer circumference of the hollow fiber membrane bundle 1. In the embodiment shown in FIG. 3, the same reference numerals as those in FIG. 1 denote the same components as those in FIG.

In any of the above-mentioned embodiments, it is desirable that the passage hole of the plate-shaped resin block has a hole diameter equal to or larger than the diameter of the supply liquid pipe to the filter in order to reduce the pressure loss.

<Effect of the Invention> The filter according to the present invention has the above-described configuration,
Most of the raw water flows into the filter through the passage holes of the plate-shaped resin block, and the conical passage of the hollow fiber membrane bundle is spread by this inflowing raw water. A sufficient gap can be secured between the membranes,
In addition, since the inner diameter of the conical passage in the hollow fiber membrane bundle is made sufficiently large, the resistance of the passage can be lowered, and therefore, the raw water can be smoothly supplied to the hollow fiber membrane mutual gaps, which is stable. Permeate flux can be obtained. Further, when the gel layer adheres to the hollow fiber membranes, the filter is removed from the tap water, immersed in the cleaning solution, and the plate-shaped resin block is moved to bend the hollow fiber membranes so that the hollow fiber membranes slide on each other. The gel layer can be efficiently removed by moving the filter, and the filter can be easily cleaned.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, and FIG.
11 is a sectional view taken along line II-II in FIG. 3, FIG. 3 is an explanatory view showing another embodiment of the present invention, and FIG. 4 is an explanatory view showing a conventional example. 1 ... Hollow fiber membrane bundle 2 ... Plate-shaped resin block 20 ... Passage hole 3 ... Envelope cylinder 4 ... Resin partition wall 5 ... Conical passage

Claims (1)

[Scope of utility model registration request] 1. A hollow fiber membrane bundle is housed in an outer casing, one end of the hollow fiber membrane bundle is opened to the outside of the outer casing through a resin partition wall, has a passage hole in the center, and is connected to the outer casing. The other end of the hollow fiber membrane bundle is embedded in a plate-shaped resin block having a gap of 1.0 mm or less, and the hollow fiber membrane bundle has a conical shape from the passage hole of the block toward the resin partition wall. A filter having a passage formed therein, and the passage hole diameter of the block is 0.4 to 0.6 times the outer diameter of the block.