JP2726784B2 - Water purifier filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purifier for filtering drinking water, a filter used in the water purifier, and a method for manufacturing the filter.

[0002]

2. Description of the Related Art In recent years, hollow fiber membranes formed by bundling porous hollow fibers having countless micropores have been widely used as filter media for filtering drinking water. A hollow fiber membrane is a type of filter that filters water using micropores on the hollow fiber wall surface.In use, water permeates through the wall surface from outside the hollow fiber and flows into the hollow fiber. Dust in the water is filtered, and the water that has flowed into the hollow fiber flows out through the opening at the end of the hollow fiber. Hollow fiber membranes have the advantage of filtering bacteria as well, since the micropores are as small as 0.01-0.1 microns.

However, when the hollow fiber membrane is used for a long time, countless bacteria adhere to the surface of the hollow fiber membrane and multiply and generate gas such as hydrogen sulfide, which causes a problem of generating an odor in the filtered water. Was. For example, sulfate-reducing bacteria generate hydrogen sulfide gas when growing. This is particularly problematic in tap water that has had chlorine removed using granular activated carbon, because the sterilizing ability is degraded.

[0004] In order to solve the problem, powdered activated carbon has been conventionally used. Japanese Patent Laid-Open No. 1-143 discloses a production method for uniformly disposing powdered activated carbon in water.
No. 685. That is, the powdered activated carbon is evenly arranged by injecting the powdered activated carbon from the other end while sucking air from one end of the case containing the granular activated carbon. Next, another case containing the hollow fiber membrane is fitted into the case, and water is allowed to flow from the granular activated carbon side, so that the powdered activated carbon adheres to the surface of the hollow fiber membrane.

[0005]

However, the conventional filter and the method for manufacturing the filter have the following problems. (1) Many bacteria adhere to the downstream side of the hollow fiber membrane, that is, the outlet side of the filter, and generate an unpleasant odor. However, according to the conventional filter manufacturing method, powdered activated carbon concentrates on the upstream side of the hollow fiber membrane. Is attached. Therefore, the off-flavor generated on the downstream side of the hollow fiber membrane cannot be absorbed, and the off-flavor is generated in the filtered water, which has been a problem. (2) If too much powdered activated carbon is added, there is a problem that when water is first passed through, powdered activated carbon adheres to the wall surface of the chamber to form a film and narrow the flow path.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a water purification apparatus, a filter, and a method of manufacturing a filter that stably supply clean water free of bacteria and an unpleasant odor. With the goal.

[0007]

In order to achieve this object, a method for manufacturing a filter of a water purification apparatus according to the present invention comprises a first chamber containing a hollow fiber membrane formed by bundling porous hollow fibers;
A method for producing a filter of a water purification device having a second chamber for accommodating granular activated carbon, comprising placing powdered activated carbon at one end of the first chamber and near the second chamber, and from the other end of the first chamber. It is characterized in that air is sucked out and powdered activated carbon is attached to the surface of the hollow fiber membrane.

In order to achieve this object, the filter of the water purification apparatus of the present invention comprises a first chamber containing a hollow fiber membrane formed by bundling porous hollow fibers, and a second chamber containing a granular activated carbon. And a powder activated carbon wrapped in a nonwoven fabric at one end of the first chamber and near the second chamber.

In order to achieve this object, the water purification apparatus of the present invention has a first chamber for storing a hollow fiber membrane formed by bundling porous hollow fibers, and a second chamber for storing granular activated carbon. A water purifier using a filter, wherein a pH value of water in the first chamber is set to 7.5 or more and 8.0 or less.

[0010]

The granular activated carbon housed in the second chamber of the present invention having the above structure removes chlorine components in tap water. Further, in the hollow fiber membrane formed by bundling the porous hollow fibers housed in the first chamber, water flows into the hollow fiber from the outside of the hollow fiber through the micropores on the wall surface during use. Since the micropores of the hollow fiber membrane 3 are as small as 0.01 to 0.1 μm, bacteria, iron rust, mold and nigori are also filtered.

The filtered bacteria, especially the sulfate-reducing bacteria, grow near the opening 3a of the hollow fiber membrane and generate hydrogen sulfide. However, the coral powder wrapped in the nonwoven fabric at one end of the first chamber and near the second chamber keeps the pH value of the water in the first chamber at 7.5 or more and 8.0 or less. Therefore, the growth of sulfate-reducing bacteria is suppressed.

Further, at the time of manufacturing the first chamber which is a filter, powdered activated carbon is arranged at one end of the first chamber near the second chamber, and air is sucked out from the other end of the first chamber to the outside. Powdered activated carbon is attached to the surface of the hollow fiber membrane. Therefore, the powdered activated carbon is filled in the opening 3 of the hollow fiber membrane.
Since the powdered activated carbon absorbs the hydrogen sulfide generated by the growth of bacteria, it is not disposed in the vicinity of a.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A water purification apparatus, a filter and a method for manufacturing the same according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view illustrating the entire configuration of the water purification device 2. The filter cartridge 1 is detachably attached to the main body. Although the structure of the filter cartridge 1 will be described later in detail, the filter cartridge 1 is composed of two hollow fiber membrane chambers 21. Further, the nonwoven fabric filter 4 is disposed above the hollow fiber membrane chamber 21.

In the space between the outer wall of the hollow fiber membrane chamber 21 and the inner wall of the main body of the filter cartridge 1, the granular activated carbon 5
Is arranged. A water input port 25 is attached to the lower left portion of the water purification device 2, and a water pipe is piped from the tap water tap to the input port 25. A flow meter 6 is attached to the lower right part of the water purification device 2. An electronic display unit 7 is provided above the flow meter. Water output port 24 on the upper surface of water purification device 2
Is fitted with a bellows tube 8.

Next, the operation of the water purification device 2 having the above configuration will be described. After passing through the input port 25, the water passes through the flow meter 6, and is branched into two hands under the filter cartridge 1.
And flows into the two hollow fiber membrane chambers 21. 2
The water flowing out of the two hollow fiber membrane chambers 21 joins below the filter cartridge 1 and flows out of the bellows tube 8 through the outlet port 24.

The flow rate type 6 measures the flow rate of tap water flowing through the water purification device 2, and when the service limit of the filter cartridge 1 is approaching, a display for instructing replacement is performed. The filter cartridge 1 can be easily removed and attached to the water purification device 2, and the user can always replace the filter cartridge 1 with the replacement display to supply clean water.

Next, the configuration of the filter cartridge 1 will be described in detail. FIG. 2 shows a cross-sectional view of the filter cartridge 1. Filter cartridge 1 is lower case 1
1 and the middle case 12 are fitted together, and the middle case 12 and the upper case 18 are fitted together to form the entire outer case. In addition, the lower case has an inlet port 9 and an outlet port 1
0 is formed. The filter cartridge 1 is separated into two left and right filter portions by a middle plate 19.

Since the main parts are symmetrical, only the right part will be described, and the description of the left part will be omitted. A hollow fiber membrane chamber 21 containing the hollow fiber membrane 3 is provided at the center. Here, the hollow fiber membrane 3 is a kind of filter that filters water using micropores on the hollow fiber wall surface. The function of the hollow fiber membrane is that when used, water penetrates the wall from outside the hollow fiber and flows into the hollow fiber.At that time, the dust in the water is filtered, and the water flowing into the hollow fiber is removed at the end of the hollow fiber. Opening 3a
(Lower in the figure) flows out. The hollow fiber membrane 3 has the advantage of filtering bacteria, iron rust, mold and nigori that cannot be removed with activated carbon, because the micropores are as small as 0.01 to 0.1 microns.

A non-woven fabric bracket 22 is provided above the hollow fiber membrane chamber 21, and the non-woven fabric filter 4 is accommodated in the non-woven fabric bracket 22. Non-woven fabric filter 4
Is a case where powdered activated carbon and coral powder are stored in a bag made of nonwoven fabric. Here, powdered activated carbon is 200
Uses mesh. In addition, the coral powder is 30-8
0 mesh is used. The non-woven fabric used does not allow passage of particles having a large particle size of 100 mesh or less. Therefore, from inside a bag made of non-woven fabric,
Powdered activated carbon goes out, but coral powder does not go out. Further, the nonwoven fabric bracket 22 has a net shape, and the storage portion of the nonwoven fabric filter 4 and the storage portion of the hollow fiber membrane 3 communicate with each other.

A hole communicating with the water outlet port 10 is provided at a position of the middle case 12 opposite to the center of the hollow fiber membrane 21, and the housing portion of the hollow fiber membrane 3 and the water outlet port 10 communicate with each other. A donut-shaped lower filter 14 is fixed around the hole by a lower filter retainer 13. Hollow fiber membrane chamber 21
Is a hollow cylindrical space between the outer wall of the upper case 18 and the inner wall of the upper case 18.
Is stored. As the granular activated carbon A15, 42 to
A granular activated carbon having a particle size of 80 mesh is used.

Above the granular activated carbon A15, a mixed activated carbon 17 is stored. Mixed activated carbon 17 is 4
It is a mixture of granular activated carbon having a particle size of 2 to 80 mesh and coral powder having a particle size of 30 to 80 mesh. Above the mixed activated carbon 17, a granular activated carbon B20 is stored. As the granular activated carbon B20, granular activated carbon having a relatively large particle size of 8 to 32 mesh is used. A 30-mesh stainless steel filter 16 inside the granular activated carbon B20 and between the nonwoven fabric bracket 22
Is attached.

Next, the operation of the filter cartridge 1 having the above configuration will be described. Explanation will be given along the flow of water. The tap water that has entered through the water inlet port 9 immediately branches right and left, and travels to the right hollow fiber membrane chamber 21A and the left hollow fiber membrane chamber 21B. The reason why the two hollow fiber membrane chambers 21 are used is that the filtering ability of the hollow fiber membrane 3 is low and only one hollow fiber membrane cannot be filtered when a large amount of tap water is flowed. The branched tap water is supplied to the lower filter 1
4 and enters the granular activated carbon A15. Here, the lower filter 14 is for removing dust in tap water.

The granular activated carbon A15 absorbs a chlorine component in tap water. Chlorine kills 99% of bacteria in tap water, and it is indispensable to add chlorine to tap water for supply of tap water, but when used as a drink, chlorine produces an unpleasant odor. Reduce. Therefore, the chlorine contained in the tap water is absorbed by the granular activated carbon A15. Next, the water passes through the mixed activated carbon 17. The coral mixed in the mixed activated carbon 17 adds a mineral component to water.

Next, the water passes through the granular activated carbon B20. The granular activated carbon B20 further absorbs chlorine remaining in water. Next, it passes through the stainless steel filter 16 and the nonwoven fabric filter 4. The stainless filter 16 prevents the granular activated carbon from flowing into the hollow fiber membrane storage unit.

The water is made weakly alkaline with a pH value of 7.5 or more and 8.0 or less by the coral powder in the nonwoven fabric filter 4. Water is made weakly alkaline because bacteria that grow on the wall surface of the hollow fiber membrane and generate hydrogen sulfide are particularly vulnerable to alkalis, and in weak alkalis, there is little growth, so there is little hydrogen sulfide generated and there is no unpleasant odor. Because it is suppressed.

That is, FIG. 4 shows data on the amount of hydrogen sulfide generated by bacteria in water. Here, general germs are A
As shown in Fig. 7, a large amount of hydrogen sulfide is generated when the pH value is between 7 and 9. However, the sulfate-reducing bacteria on the wall surface of the hollow fiber membrane, which are supposed to generate hydrogen sulfide by multiplication, generate the maximum amount of hydrogen sulfide when the pH value is 7 as shown in B in the figure. However, when the pH value becomes 7.5 or more, the amount of generated hydrogen sulfide rapidly decreases.

Therefore, it is necessary to make the pH near the opening 3a of the hollow fiber membrane, in which a large amount of bacteria are generated and multiply to generate hydrogen sulfide, a weak alkali of 7.5 or more. Conventionally, water was made weakly alkaline by coral powder mixed with granular activated carbon, but in that case, the distance to the opening 3a of the hollow fiber membrane was long, and water near the opening 3a3a of the hollow fiber membrane was long. The alkalinity of the water became weak and it was almost neutral.

In this embodiment, the coral powder is disposed immediately near the hollow fiber membrane 3, so that the water is made weakly alkaline by the coral powder and the water near the opening 3a of the hollow fiber membrane is formed. The pH value can be maintained at 7.5 or more and 8.0 or less. Here, since the water quality standard of tap water by the Ministry of Health and Welfare specifies that the pH value is 5.8 or more and 8.6 or less, in this embodiment, the pH value is set to 8.0 or less in consideration of safety. I have.

When the pH value is 8.0 or more, there is a problem that the generated hydrogen sulfide is decomposed, ionized, and dissolved in purified water. Ionized hydrogen sulfide cannot be absorbed by powdered activated carbon. When using purified water, for example, if ice has a pH value of about 7.3 when ice is added, the ice melts into the purified water, and the pH value of water becomes 8.0 or less. In addition, dissolved hydrogen sulfide is generated, generating an off-flavor. This also applies, for example, when rice is ground with water and the pH value is 8.0 or less.

Next, the weakly alkaline water flows into the hollow fiber membrane 3. The function of the hollow fiber membrane 3 is as follows. At the time of use, water flows from the outside of the hollow fiber into the hollow fiber through the micropores on the wall surface. Here, since the micropores of the hollow fiber membrane 3 are as small as 0.01 to 0.1 micron, bacteria, iron rust, mold and nigori are also filtered. Then, dust and bacteria in the water are filtered, and the water that has flowed into the hollow fiber flows out through the opening 3a (the lower side in the figure) at the end of the hollow fiber.

At this time, the filtered bacteria are transferred to the hollow fiber membrane 3
However, most of the bacteria concentrate in the vicinity of the opening 3a of the hollow fiber membrane 3 on the lower side in the figure because the water flowing later gradually flows downstream. Therefore,
Bacteria grow and produce hydrogen sulfide as they grow. However, in the water purification device 2 of the present embodiment, the opening 3 of the hollow fiber membrane 3
Since the pH value of water in the vicinity of a is 7.5 or more and 8.0 or less, as shown in FIG. 4, the growth of sulfate-reducing bacteria is suppressed, the generation of hydrogen sulfide is small, and the unpleasant odor attached to the water is small. .

Further, as described later, the hollow fiber membrane 3
Powdered activated carbon is attached to the outer wall of the hollow fiber membrane 3 around the periphery of the hollow fiber membrane 3, particularly near the opening 3a, so that even if sulfuration occurs due to bacterial growth, the generated hydrogen sulfide is absorbed by the powdered activated carbon. Therefore, there is almost no off-flavor attached to the water. Next, the water that has flowed through the opening 3a through the inside of the hollow fiber membrane 3 merges with the water that comes out of the hollow fiber membrane chamber 21B on the left side and flows out from the water discharge port.

Next, a method of manufacturing the hollow fiber membrane chamber 21 as a filter for disposing powdered activated carbon around the hollow fiber membrane 3 will be described. As shown in FIG. 3, a nonwoven fabric bracket 22 is attached to an upper portion of a hollow fiber membrane chamber 21 in which a hollow fiber membrane 3 is housed.
In 2, place a nonwoven bag containing a mixture of powdered activated carbon and coral powder. Since the powdered activated carbon and the coral powder are placed in a non-woven bag, the powder and the like do not scatter and enter other parts of the apparatus, and do not adversely affect the apparatus. In addition, workers do not inhale powder etc.,
Worker safety is ensured.

Then, the air F is sucked from the outlet 21 a at the lower part of the hollow fiber membrane chamber 21, thereby lowering the atmospheric pressure of the storage part of the hollow fiber membrane 3, and the powdered activated carbon is placed around the hollow fiber membrane 3. To do it. Here, powder activated carbon uses 200 mesh, and coral powder uses 30 to 80 mesh. On the other hand, the non-woven fabric used is one that does not allow particles with a large particle size of 100 mesh or less to pass through, so from inside a bag made of non-woven fabric, powdered activated carbon goes out, but coral powder goes out. Does not appear. Therefore, only the powdered activated carbon is sucked and placed around the hollow fiber membrane 3.

If the air F is sucked too strongly, the micropores of the hollow fiber membrane 3 are crushed, so it is necessary to suck the air F with a weak suction force. Since the outer wall of the hollow fiber membrane chamber 21 is translucent, the powdered activated carbon is coated in the opening 3 of the hollow fiber membrane 3.
It can be confirmed that they are arranged around a. Thereby, the powdered activated carbon can be arranged near the opening 3 a of the hollow fiber membrane 3.

The present invention is not limited to the above embodiment, but can be applied to various applications. For example, powdered activated carbon may be arranged near the opening 3a of the hollow fiber membrane 3 by sucking air from the water outlet port in a state where the activated carbon is incorporated in the filter cartridge 1. Also, the powdered activated carbon and coral powder may be stored in a bag or box of another filter instead of a non-woven bag. Further, in this embodiment, coral powder is used to maintain water to be weakly alkaline, but other weakly alkaline substances may be mixed.

[0037]

As is apparent from the above description, according to the method for manufacturing a filter of the present invention, one end of the first chamber containing a hollow fiber membrane formed by bundling porous hollow fibers, The powdered activated carbon is arranged near the second chamber for accommodating the granular activated carbon, air is sucked out from the other end of the first chamber to the outside, and the powdered activated carbon is attached to the surface of the hollow fiber membrane. Since powdered activated carbon adheres to the surroundings, particularly to the outer wall of the hollow fiber membrane near the opening, which is downstream, even if sulfuration occurs due to the growth of bacteria, the generated hydrogen sulfide is absorbed by the powdered activated carbon. Almost no off-flavors.

Further, according to the water purification apparatus of the present invention, the pH value of the water in the first chamber containing the hollow fiber membrane formed by bundling the porous hollow fibers is set to 7.5 or more and 8.0 or less. The odor of water can be reduced by reducing the growth of bacteria, especially sulfate-reducing bacteria, and reducing the generation of hydrogen sulfide. Further, since the unpleasant odor of water is reduced, the replacement cycle of the filter cartridge can be lengthened, and the cost can be reduced as a whole.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a water purification device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a filter cartridge according to an embodiment of the present invention.

FIG. 3 is an explanatory view showing a method of manufacturing a filter according to an embodiment of the present invention.

FIG. 4 is a data diagram showing the relationship between the generation of hydrogen sulfide by bacteria and the pH value of water.

[Explanation of symbols]

 Reference Signs List 1 filter cartridge 2 water purification device 3 hollow fiber membrane 4 nonwoven fabric filter 5 granular activated carbon A 17 mixed activated carbon 20 granular activated carbon B 21 hollow fiber membrane chamber

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-2666893 (JP, A) JP-A-3-296483 (JP, A) JP-A-5-18691 (JP, U)

Claims (2)

(57) [Claims] 1. A filter of a water purification device having a first chamber containing a hollow fiber membrane formed by bundling porous hollow fibers and a second chamber containing granular activated carbon, wherein one end of the first chamber is provided. non-Te in the second chamber closer
Filter the water purification device, characterized in that arranged powdered activated carbon wrapped in fabric. 2. A filter for a water purification apparatus according to claim 1.
In addition , coral powder is arranged in the nonwoven fabric together with the activated carbon powder.
A filter for a water purification device, which is provided.