JP3112927B2 - Water purifier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a water purifier comprising a group of hollow fiber membranes, an activated carbon layer, and a raw water filter.

[Prior art] In recent years, a water purifier having a hollow fiber membrane group and an activated carbon layer as a basic configuration has been used to remove unpleasant odors and tastes due to residual chlorine in tap water, and colloidal iron powder floating and sinking in raw water. It is used to remove fine foreign matter and foreign substances such as bacteria, and the range of use has been dramatically expanded.

In these conventional water purifiers, most of the water to be treated passes from the outer surface of the hollow fiber membrane to the inner surface of the hollow fiber membrane through the membrane wall, and the above-mentioned various types of water are formed by the fine porous wall of the hollow fiber membrane. It is configured to remove foreign matter. Therefore, the above foreign substances accumulate on the outer surface of the hollow fiber membrane by passing water, but when the membrane reaches a state where most of the membrane surface is covered, the filtration ability is almost lost, and the life of the water purifier ends. It will arrive.

For this reason, the appearance of a water purifier that functions effectively only at the time of water purification treatment and has a long service life has been desired, but such a water purifier has not been found before.

[Problem to be Solved by the Invention] The water purifier of the present invention improves the above-mentioned drawbacks of the conventional water purifier, and reverses the water flow direction of the conventional product from the inside to the outside of the hollow fiber membrane. , And the inner surface of the hollow fiber membrane can be constantly washed with so-called primary filtered water so that foreign substances in the raw water do not adhere and accumulate except during the water purification treatment.

An object of the present invention is to provide a long-life water purifier in which the coating of the hollow fiber membranes with the deposits is reduced as much as possible, and the cumulative filtration capacity is remarkably enhanced.

Means for Solving the Problems According to the present invention, a cylindrical case 1 having a secondary filtered water passage hole 10 in an outer peripheral portion and having both ends opened is provided. Hollow fiber membrane group 6 housed and open at both ends, resin fixing layers 9 and 9 'for liquid-tightly fixing the end of the hollow fiber membrane group and the open end of the cylindrical case, outer peripheral surface of the cylindrical case And an outer cylinder case 2 having an activated carbon layer 7 and one or more purified water outflow holes 8, a raw water inflow cap 4 having a raw water filter 5 on both ends of the cylindrical case, and a primary filtered water outflow. It has a cap 12, and the raw water filter 5 is disposed on the entire upper surface of the resin fixing layer 9 on the raw water inflow side of the cylindrical case 1 and has pores at least smaller than the inner diameter of the hollow fiber membrane. It is a water purifier.

Examples of the material of the hollow fiber membrane used in the present invention include known porous hollow fiber membranes such as polyolefin, cellulose, polysulfone, polyvinyl alcohol, and polyacrylonitrile.

Examples of the material of the activated carbon layer used in the present invention include granular activated carbon or molded activated carbon obtained by solidifying granular activated carbon with a small amount of a binder, and activated carbon fiber or an activated carbon fiber molded product obtained by solidifying the same with a small amount of a binder. And the like.

The raw water filter disposed on the upper surface of the resin fixing layer on the raw water inflow side of the cylindrical case 1 may be a mesh filter having fine pores made of a knitted or woven fabric of metal or fiber, or a substantially non-woven fabric made of the same. Or a sintered body or a ceramic filter made of them.

[Operation] The present invention will be described in more detail with reference to the drawings. FIG. 1 schematically shows a cross section of the water purifier of the present invention.

Raw water such as tap water flows in from a raw water inlet 3 and passes through a raw water inflow cap 4 and passes through a raw water filter 5, where the first-stage treatment is performed to obtain primary filtered water.

The size of the pores of the raw water filter 5 may be smaller than the inner diameter of the hollow fiber membrane 6, which will be described later.
May be fixed to the outer peripheral surface of the upper end of the cylindrical case 1 closely or to the inner peripheral surface of the raw water inflow cap 4.

The primary filtered water that has passed through the raw water filter 5 is then removed from each hollow fiber of the hollow fiber membrane group 6 having an opening cross section on the surface of the resin fixing layer 9 formed below the filter 5 at the upper end of the cylindrical case 1. The cylindrical case 1 passing through the inner hollow portion of the membrane
It flows out from the primary filtered water outlet 13 through the opening cross section of the resin fixing layer 9 'at the lower end and the primary filtered water outflow cap 12.

Therefore, the primary filtered water subjected to only the first-stage treatment directly flows out without undergoing the second-stage treatment by the hollow fiber membrane group 6 or the activated carbon layer 7.

In order to function as the original water purifier and obtain so-called purified water, it is built in the primary filtered water outflow cap 12,
Or an on-off valve connected to the cap 12 and beyond (not shown)
Is closed, and the primary filtered water is passed through the hollow fiber membrane group 6 and the activated carbon layer 7 to perform the second-stage treatment.

In this case, the primary filtered water that has passed through the raw water filter 5 passes through the membrane wall from the inside to the outside of the hollow fiber membrane 6 and is filtered to become secondary filtered water.

Fine porosity is formed on the membrane wall of each hollow fiber,
As a result, the second stage processing is performed. The finer colloidal iron powder, dust, bacteria, and the like that are not removed by the raw water filter 5 and floated and sink in the water are removed, and secondary filtered water is obtained here.

The second-stage treated water flowing out from the inside to the outside of each hollow fiber membrane through the membrane wall passes through a group of secondary filtered water passage holes 10 provided in the outer peripheral portion of the cylindrical case 1, It passes through the activated carbon layer 7 which is in close contact with the outer surface of the case 1 and is fixed to the inner surface of the outer case 2.

By passing through the activated carbon layer 7, the third-stage treatment can be performed to remove unpleasant odors and tastes due to residual chlorine in the secondary filtered water.

It is preferable that the activated carbon layer 7 is tightly fixed to the cylindrical case 1 so that the secondary filtered water always passes through the activated carbon layer 7.

The third-stage treated water that has passed through the activated carbon layer 7 becomes purified water, and is collected in a gap 11 formed in the space between the inner surface of the outer cylinder case 2 and the outer surface of the activated carbon layer 7, and is collected by the outer cylinder case 2. It flows out from the provided purified water outflow hole 8.

The number of the purified water outflow holes 8 may be one or more.

Although the pressure loss naturally occurs in the activated carbon layer 7, the pressure loss sometimes becomes non-uniform, and depending on the position of the purified water outflow hole 8, the third-stage treated water from the activated carbon layer 7 near the outflow hole 8 having a small pressure loss The phenomenon that the outflow of water increases.

For this reason, it is preferable to make the pressure loss in the activated carbon layer 7 uniform over the entire circumference. For example, the hole diameter of the secondary filtered water passage hole group 10 of the cylindrical case 1 is gradually changed so as to make the pressure loss uniform near the purified water outflow hole 8, or the gap portion is formed.
It is also preferable that the shape of 11 is changed so that the pressure loss becomes uniform regardless of the position of the outflow hole 8.

Therefore, when simply obtaining the primary filtered water, the switching operation of the on-off valve, that is, the built-in or outlet hole 8
This can be easily obtained by closing the on-off valve connected thereafter and opening the on-off valve built in or connected to the primary filtered water outflow cap 12.

When obtaining purified water, the valve may be opened and closed in the opposite direction. This can be easily achieved by using a three-way valve or the like to simultaneously open and close the valve.

The inner surface area of the hollow fiber membrane is limited due to the restrictions on the form as a water purifier, and by continuously washing and removing various foreign matters deposited on the limited inner surface, an increase in water flow resistance is prevented. You can do it.

Comparing the amounts of normal purified water and primary filtered water used for washing dishes, washing vegetables and fish, and the like, the latter is overwhelmingly large.

Therefore, it is possible to secure desired purified water for a long period of time by constantly washing the inner surface of the hollow fiber membrane to remove the deposits by using the primary filtered water.

[Example] Hereinafter, an example using the purifier of the present invention having the structure shown in Fig. 1 will be described, but the present invention is not limited to these.

Example 1 and Comparative Example 1 As the hollow fiber membrane group, a polyethylene hollow fiber membrane having an inner diameter of 270 μm and a thickness of 55 μm (EHF-270T manufactured by Mitsubishi Rayon Co., Ltd.)
The hollow fiber membrane was bundled with 7,776 fibers, and both ends were fixed with resin so that the effective hollow fiber length was 123 mm. The outer periphery of the hollow fiber membrane was activated carbon fiber (A-15 manufactured by Osaka Gas Co., Ltd.). The outer diameter
A water purifier provided with an activated carbon layer molded to 81 mm, an inner diameter of 57 mm and a length of 123 mm was prepared, and a water flow test was performed using the same water purifier under the same test conditions in different water flow directions.

That is, water was passed through one side in the order of the inner surface of the hollow fiber membrane, the same outer surface, and the activated carbon layer in the same manner as in the present invention.

Also, the other is the same as the conventional product (opposite to the present invention),
Water was passed through the activated carbon layer, the outer surface of the hollow fiber membrane, and the inner surface in this order.

 Table 1 shows the above results.

The water flow test was performed under the following conditions.

Raw water: Nagoya city Water temperature: 6-17 ° C Flow rate: 4 / min. Flow rate: 200 / day Flow rate of cleaning water inside the hollow fiber membrane: 750 / day (primary filtered water, only used in Example 1) Shows that the water purifier of the present invention has a clearly higher flow rate and flow rate even after passing a large amount of water than the conventional water purifier of the comparative example.

[Effects of the Invention] In the water purifier of the present invention, when the purified water is not required, only the first-stage treatment for obtaining the primary filtered water can be performed by switching the open / close valve, At this time, since the inner surface of the membrane is washed by the primary filtered water that passes through the inner surface of the hollow fiber membrane, most of various foreign substances deposited on the inner surface of the hollow fiber membrane during the water purification treatment hardly remain on the membrane surface. Further, since the increase in pressure loss is greatly reduced, a large amount of desired purified water can be secured over a long period of time.

Therefore, the water purifier of the present invention has a function different from that of the conventional water purifier as described above, that is, a structure in which the surface of the hollow fiber membrane can always be washed with primary filtered water except when obtaining purified water. It is more economical than water purifiers because it is more reasonable and efficient, and has a very long life.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view showing the structure of the water purifier of the present invention. 1: Cylindrical case 2: Outer case 3: Raw water inlet 4: Raw water inflow cap 5: Raw water filter 6: Hollow fiber membrane group 7: Activated carbon layer 8: Purified water outlet 9,9 ': Resin fixed layer 10: Two Secondary filtered water passage hole 11: Void 12: Primary filtered water outlet cap 13: Primary filtered water outlet

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C02F 1/44 B01D 63/02 B01D 65/02 B01D 65/08 C02F 1/28

Claims (2)

(57) [Claims] 1. A cylindrical case 1 having a secondary filtered water passage hole 10 at its outer peripheral portion and having both ends opened. The cylindrical case 1 is linearly bundled and stored in the cylindrical case, and both ends are opened. Hollow fiber membrane group 6, resin fixing layers 9 and 9 'for fixing the ends of the hollow fiber membrane group and the open ends of the cylindrical case in a liquid-tight manner, and activated carbon layers 7 and 1 in contact with the outer peripheral surface of the cylindrical case It comprises an outer cylinder case 2 having at least two purified water outflow holes 8, and a raw water inflow cap 4 having a raw water filter 5 and a primary filtered water outflow cap 12 at the outer side of both end faces of the cylindrical case. Water purifier. 2. The water purification apparatus according to claim 1, wherein the raw water filter is disposed on the entire upper surface of the resin fixing layer on the raw water inflow side of the cylindrical case, and has pores at least smaller than the inner diameter of the hollow fiber membrane. vessel.