JP4210964B2 - Water purifier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water purifier that removes and reduces particulate components and chemical components contained in water.
[0002]
[Prior art]
The basic functions of a water purifier can be broadly divided into two.
One of them is a function of removing suspended substances contained in the water to be treated.
Suspended substances in water, for example, iron rust and fine dust can be considered, but recently, so-called chlorine resistance that can not be killed using chlorine that is contained in tap water and commonly used in tap water This category also includes protozoa that are harmful to the human body, such as Cryptosporidium and Giardia. As a method for removing these suspended substances, a generally popular method is mechanical removal using a hollow fiber membrane. The hollow fiber membrane has a large number of pores of about 0.1 μm on the side wall of the straw-like membrane, and when the water to be treated passes through it, a large suspended substance or a very fine suspended substance such as bacteria Until then, it will be collected and separated together. The hollow fiber membrane has a fine separation performance as described above, but has the disadvantage that the life of filtration is extremely short. One of the ideas for improving this disadvantage is Japanese Utility Model Publication No. 3-047089. According to this device, by providing a prefilter having an average gap of 20 μm to 50 μm on the upstream side of the hollow fiber membrane, coarse suspended substances are captured by this filter, and the load on the hollow fiber membrane is reduced, thereby reducing the hollow fiber membrane. It is trying to extend the service life by suppressing clogging.
One of the other functions of the water purifier is the removal of chemical substances. Examples of chemical substances contained in water include chlorine, trihalomethane, which is a carcinogen, and geosmin and dimethylisoborneol, which cause musty odor. As a method for removing these chemical substances, a method that has been widely used is removal by a chemical reaction using activated carbon and an adsorption action. When activated carbon is largely separated from its shape and properties, it is classified into fibrous, granular and solid forms. Fibrous activated carbon is formed by laminating and carbonizing organic polymers processed into fibers. As a general property, the removal performance is high when the flow rate of treated water is large, that is, when the residence time is short. It can be demonstrated. In addition, granular activated carbon activates coal and coconut shells to create a large number of pores. As a general property, it exhibits its performance when the flow rate of treated water is relatively small, that is, when the residence time is relatively long. can do. Solid activated carbon is manufactured by a method such as putting a binder in granular activated carbon and sintering it, and is used for the purpose of combining the ease of handling and the removal of suspended solids rather than the chemical removal performance of activated carbon. In particular, no features or superiority are found in the removal performance of chemical substances. Compared with fibrous activated carbon and granular activated carbon, as described above, fibrous activated carbon has advantages in terms of the flow rate of treated water, but granular activated carbon is superior when it exceeds a certain grade in terms of chemical substance removal capacity per unit weight. In addition, in terms of economic efficiency, granular activated carbon has an advantage because it is approximately 1/5 the price of fibrous activated carbon.
Examples of the invention having both the suspended substance removing function and the chemical substance removing function of the water purifier described above are Japanese Utility Model Laid-Open No. 3-047089 and Japanese Patent Laid-Open No. 10-113507 cited above.
According to Japanese Utility Model Publication No. 3-047089, in addition to the configuration in which chemical substances are removed by conventional fibrous activated carbon and suspended substances are removed by hollow fiber membranes, suspension in fibrous activated carbon is performed. A prefilter with an average air gap of 20 to 50 μm is installed on the uppermost stream side of the filter unit in order to prevent degradation of performance and water flow due to masking of the active surface due to adhesion of substances, and prevention of water flow reduction due to the life of the hollow fiber membrane. ing.
Further, according to the published patent publication of JP-A-10-113507, a fibrous activated carbon formed into a cylindrical shape from the upstream side, and a pleat filter disposed on the downstream side to form a two-layer structure. And the suspended matter is removed by a pleated filter layer.
[0003]
[Problems to be solved by the invention]
However, as described above, when a hollow fiber membrane is used, the filtration life is considerably shortened. As a measure for improving this, in JP-A-3-047089, a pleated membrane-like prefilter is disposed on the upstream side. However, compared to the hollow fiber membrane having a pore diameter of 0.1 μm, the effect of prolonging the service life cannot be expected with a prefilter having an average gap of 20 μm to 50 μm described in Japanese Utility Model Publication No. 3-047089. Moreover, there is a disadvantage that the water purifier itself becomes larger by newly adding a pleated membrane.
Further, as described in JP-A-10-113507, when the cylindrical fibrous activated carbon and the pleated filter are arranged in this order from the upstream side of the treated water, in order to secure the membrane area of the pleated filter, Not only has the diameter of the core of the water collecting pipe at the center increased and the water purifier itself becomes larger, but the suspended carbon adheres to the surface of the fibrous activated carbon placed upstream, and the activated carbon originally has it. The performance of the activated carbon is remarkably deteriorated, or the fibrous activated carbon itself is clogged, and the water resistance is increased within a short period of time.
In general, a pleated filter exerts a force to spread outward when a force is applied to the membrane itself from the inside to the outside. In particular, a strong mechanical stress is applied to the sealing portions at both longitudinal ends of the pleated filter. The problem is that this part of the film is damaged and cannot perform.
Further, considering the original performance of the activated carbon, the granular activated carbon has an advantage as described above. However, in the examples of Japanese Utility Model Laid-Open No. 3-047089 and Japanese Patent Laid-Open No. 10-113507, which are mentioned above, the activated carbon is both fibrous. Activated carbon is used. The reason for this is presumed to be mainly because they are molded, easy to handle and almost no fine powder is produced. In the case of using granular activated carbon, it means that the handling property, particularly the filling of the activated carbon layer and the leakage of fine powder become a problem.
Further, if the filter membrane is exposed, there is a risk that the pleated filter may be damaged in, for example, a filter assembly process, and the performance of the filter may be deteriorated.
In addition, the filter membrane is generally weak in mechanical strength. In particular, when the treated water permeates in a state where the pressure loss of the filter membrane is high, the filter membrane is subjected to mechanical stress, and there is a risk of reducing the performance. is there.
In addition, as mentioned earlier, protozoa that are harmful to humans, such as chlorine-resistant Cryptosporidium and Giardia, which are not effective in chlorination of tap water, have recently been found in tap water. It is becoming an obligation of water purifiers to perform treatment. When considering the performance of a pleated filter membrane, in order to ensure the required filtration performance depending on the purpose of use, it is customary to develop a filter membrane that exhibits the corresponding membrane performance. Had to spend considerable time and money.
Also, as one of the major problems when using pleated filters, if the suspended material passing through the filter is in the form of clay, the pleat filter folds and folds will coalesce and the filter area will decrease substantially, resulting in filtration. There was a problem that the lifetime was shortened. Further, when the treated water does not pass through the activated carbon layer, there has been a problem that the chemical substance removal performance is extremely lowered.
In addition, the end face in the longitudinal direction of the pleated filter is generally welded to the cap or sealed with a resin. However, the welding requires a considerable equipment investment, and the welding boundary surface is filtered. There is a problem of securing the performance of the film, and technical and cost hurdles are higher than in the case of resin sealing. Compared to this, sealing with resin is relatively easy, but if resin is injected in some cases, the resin is sucked up by the pleated filter and does not remain sufficiently on the end face, and this part cannot be sealed, for example, When a strong force acts on the filter part and the end face adhesive seal part of the filter with a water hammer or the like, there is a problem that the adhesive seal is peeled off and the adhesive seal is easily deteriorated.
Therefore, the present invention does not cause clogging, has a long service life, does not damage the filter during the assembly process, and can remove protozoa such as chlorine-resistant Cryptosporidium and Giardia, and has a high chemical removal performance. An object of the present invention is to provide a water purifier that has high performance filtration ability, is small, has a high strength of an adhesive seal, and is inexpensive.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, a representative invention of the present application has the following configuration.
A case having a raw water inlet and a purified water outlet, a filter medium comprising a prefilter and a main filter loaded inside the case with a gap from an inner peripheral surface of the case, and a holding member for sealing the filter medium and fixing the filter medium in an appropriate position And in the water purifier consisting of a water collecting member with one end communicating with the water purification outlet,
The main filter is composed of a pleated filter and granular activated carbon, and the filter medium is arranged in the order of prefilter, pleated filter, activated carbon from the upstream side of the treated water,
The holding member includes a cap provided at both ends of the main filter and a cage for holding the activated carbon, and forms a pleated filter chamber in which the pleated filter is accommodated and an activated carbon chamber in which the activated carbon is accommodated.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
Example 1
FIG. 1 is a side sectional view showing an example of the water purifier of the present invention. This is loaded into a housing consisting of a body 18 and a head 18 having an inlet side joint 1 corresponding to a raw water inlet and an outlet side joint 2 corresponding to a purified water outlet, spaced from the inner peripheral surface of the case inside. The water purifier uses the pre-filter 9, the water collecting pipe 17 as a water collecting member, and the pleated filter 10 and the activated carbon filter 19 as the main filter. Reference numeral 15 denotes an O-ring that seals the connection between the outlet side joint 2 and the water collecting pipe 17. FIG. 2 is an enlarged cross-sectional view showing details of the pleated filter 10 and has a structure in which a filter membrane 21 is sandwiched between support membranes 20.
First, the treated water flows from the inlet side joint 1 through the outer water passage 8 into the housing as indicated by the water inflow direction arrow 13. Next, after removing a large suspended substance with the pre-filter 9, it passes through the pleated filter 10, passes through the cage 16, removes the chemical substance with the activated carbon 19, flows into the water collecting pipe 17, and flows out from the outlet side joint 2. As shown by the arrow 14, it is a mechanism that flows out of the water purifier.
The operation will be described. This water purifier does not use a hollow fiber membrane, and the main filtration is performed by a pleated filter. The core diameter of the pleat filter, that is, the outer diameter of the cage 16 is about 70 mm, the fold height of the pleat filter is about 15 mm, and the length is about 270 mm. The surface area of the pleat filter is 1.5 m ^2. The above can be obtained. Therefore, taking an example in a Japanese water supply, it is designed so that sufficient performance can be obtained even at a place where the original water pressure is 0.1 MPa, which is a low pressure area, even for treated water with a maximum turbidity of 2 degrees. Has been. For example, in the case of using a hollow fiber membrane, taking the above-mentioned Japanese Utility Model Publication No. 3-047089 as an example, when using a hollow fiber membrane and a pleated type prefilter, the filtration capacity is 10 m ^3. It becomes easy to see that the present invention is a high-performance water purifier.
(Example 2)
In the present embodiment, the configuration is arranged in the order of the pre-filter 9, the pleat filter 10, and the activated carbon 19 from the upstream side of the treated water. Therefore, the core diameter of the pleat filter 10 can be increased to about 70 mm. A film area of such a large pleated filter 10 of 1.5 m ² can be secured. For example, when the pleated filter 10 is located on the most downstream side and the water collecting pipe 17 has a core diameter, the membrane area that can be secured in proportion to the diameter decreases. In this example, the membrane area is only about 1/10. It can not be secured, and it can be seen that it is not practical. Conversely, when the diameter of the water collecting pipe 17 is increased so as to ensure a certain membrane area, the water purifier becomes larger than the performance, and problems such as installation location and handling may occur during use. In the case of this example, the treated water after removing suspended substances flows into the activated carbon 19, so that the suspended substances do not adhere to the activated carbon surface, and the performance of the activated carbon 19 is fully exhibited. Obviously we can do it.
(Example 3)
Example 3 will be described. Pressure is applied to the water purifier in accordance with the flow of the normal treated water, and in this embodiment as well, compression force is applied to the pre-filter 9 and the pleat filter 10 during normal water passage. The compression force is such that the pleat filter 10 is pressed against the cage 16, and the cage 16 and further the activated carbon 19 inside the cage 16 pushes back the force so that the pleat filter 10 does not cause any significant deformation. Can continue. However, for example, when the water flow is suddenly stopped at the tip of the outlet side joint 2, a so-called water hammer for avoiding the water flow energy is generated, and the pleat filter 10 is contrary to the normal water flow. A pressure is generated from the inside to the outside. Although this force is instantaneous, particularly when the pleated filter 10 is clogged with suspended substances and the pressure loss is high, the pleated filter 10 receives the water hammer, and the pleated filter 10 is moved from the inside. It receives the force that opens outward and moves. For this reason, a force is applied to the portion where the interface with the sealing portion of the pleated filter 10 is fixed and the portion which is not fixed, and this portion is damaged and the performance of the filter membrane 21 is deteriorated. In particular, in a use environment where the frequency of opening and closing is high, the repeated stress on this part becomes significant, and in some cases, the film may be broken. When the prefilter 9 is wound over the entire pleated filter 10, even if the water hammer is applied to the pleated filter 10, the entire pleated filter 10 does not move toward the outside, so that the pleated filter 10 is damaged. It does not occur and the prefilter 9 can also act stably. In the present embodiment, a belt-shaped nonwoven fabric is wound as the prefilter 9 while being spirally overlapped, but it is not necessarily a nonwoven fabric and may not necessarily be a spiral.
(Example 4)
Next, Example 4 will be described. As described above, granular activated carbon has superior chemical treatment capacity and low cost compared to fibrous activated carbon. Therefore, it is preferable to use granular activated carbon in order to demonstrate the capability of the water purifier, and granular activated carbon is also used in this embodiment.
(Example 5)
Next, Example 5 will be described. FIG. 2 shows an outline of the positional relationship between the support membrane and the filter membrane. The filter membrane 21 is composed of fibers laminated to have a hole diameter of 10 to 100 μm, and at least two of them are provided. Since it is necessary to remove fine suspended solids, it is a fine film and is usually a delicate film having a thickness of several μm to several tens of μm so as not to increase pressure loss. When handling this, the biggest problem is not to damage the membrane. Therefore, by disposing the support film on both sides so as not to touch the film directly, the handleability is improved and the reliable pleated filter 10 can be provided. Further, since the membrane has a thickness as described above, the strength of the membrane itself, that is, the “strain” is weak, and the filtration membrane 21 may be damaged by the pressure of passing the treated water. Therefore, the support film 20 is necessary.
(Example 6)
Next, Example 6 will be described. When the hole diameter of the support membrane 20 is dense, the suspended matter is captured by the support membrane 20 itself, and the pressure loss increases with time. When the pressure loss is low, the support membrane 20 can pass the water while maintaining its shape without receiving an external force. However, when the pressure loss of the support membrane 20 increases, the support membrane 20 moves in the direction of water flow. Under the force, it gradually deforms in the direction of water flow and acts in a direction to reduce the effective membrane area of the filter membrane 21. Accordingly, the support film 20 needs to have a hole diameter that does not cause pressure loss, and the value is 100 μm or more, preferably 200 μm or more.
(Example 7)
Next, Example 7 will be described. As mentioned earlier, for example, the chlorine used in tap water does not die, and removing chlorine-resistant protozoa that harm humans is also a mission imposed on the water purifier by the form of use of the water purifier. . At present, the smallest of these protozoa is a small cyst of Cryptosporidium, which is approximately 4 μm in size. US NSF International has approved this protozoa as a water purification system that can be removed by removing 99.95% or more of 3-4μm particles, and meeting this standard is one of the important performances. . In this example, it was confirmed that this specification was satisfied when a test was conducted in accordance with this standard.
(Example 8)
Next, Example 8 will be described. Conventionally, filter membranes have been developed with a great deal of development time and cost depending on the filtration accuracy. However, if the purpose can be achieved by laminating basic filter membranes, this enormous development time and cost is unnecessary, and a water purifier that uses the filter membranes to the market in a timely and relatively inexpensive manner. Can be provided. For example, when the filtration accuracy of one filter membrane is 99%, a filtration accuracy of 99.9% can be realized by laminating the same membrane with another sheet.
Example 9
Next, Example 9 will be described. When suspended matter is collected in the pleated filter 10 and pressure is applied, the membrane receives a force that is crushed inside the pleats. Further, when the suspended substance is a clay-like substance such as kaolin, for example, even if the crushing force is removed, the pleats of the pleated filter 10 do not adhere to each other, and the water passage portion is substantially concealed and the water passage portion is hidden. The area is reduced. As a method for preventing this problem, if the thickness of the support film is changed from 50 μm to 1000 μm, even if the folds are fused, a water passage having this thickness is secured, and no trouble due to adhesion occurs. Note that 1000 μm is considered to be a value that is practically difficult to increase beyond this.
(Example 10)
Next, Example 10 will be described. In the embodiment shown in FIG. 1, the activated carbon 19 is longer than the pleated filter 10. This is a structure in which the treated water that has passed through the pleated filter 10 always passes through the activated carbon 19. For example, when the length of the activated carbon 19 is the same as the end face of the pleated filter 10, the treated water is the upper cap 7 and the activated carbon 19. Since it flows into the water collection pipe | tube 17 through the interface of this, the removal performance of a chemical substance falls.
(Example 11)
Next, Example 11 will be described. As described above, when using activated carbon, granular activated carbon is desirable, but granular activated carbon is different from fibrous activated carbon, and fine activated carbon powder may flow out of the water purifier. In order to prevent this, a non-woven fabric having a gap smaller than the activated carbon particle diameter is wound around the entire outer circumference of the water collection pipe 17 and the cage 16, thereby preventing the activated carbon fine particles from flowing out of the water purifier and upstream.
Example 12
Next, Example 12 will be described. In the water purifier of FIG. 1, the water collecting pipe 17, the activated carbon 19, the cage 16, the pleated filter 10, and the prefilter 9 are integrated with the upper cap 7 and the lower cap 12 to form a filter unit. When the activated carbon is filled in the filter unit, the inlet is necessary, and the inlet is located at the position of the rubber cap 4. By injecting the activated carbon 19 in the final assembly process of the filter unit using this inlet, the activated carbon 19 is not mixed into the water collecting pipe 17 and discharged from the water purifier to the outside.
(Example 13)
Next, Example 13 will be described. Although the injection port filled with activated carbon was provided according to Example 12, even when the rubber plug 4 was attached here and the activated carbon chamber was sealed, for example, when the activated carbon 19 was at a high pressure by a water hammer or the like, There is a possibility that the rubber plug 4 is detached or a gap is formed and the activated carbon 19 is mixed into the upstream side of the water purifier. In this case, there is a possibility that a bypass path of treated water due to a decrease in the amount of the activated carbon 19 is formed in the activated carbon chamber, or the activated carbon 19 is clogged in the pleated filter 10 and the life of the pleated filter 10 may be reduced. It is necessary to prevent this. As shown in FIG. 1, since the rubber presser 3 that presses the rubber plug 4 from the head 18 is provided, the rubber plug 4 does not easily come off even if it receives a force with a water hammer or the like.
(Example 14)
Next, Example 14 will be described. The end face of the pleated filter 10 needs to be completely sealed so that the treated water does not bypass from this portion. When the resin is filled and adhesively sealed, the resin needs to remain on the end face of the pleated filter 10, but if conditions such as familiarity between the pleated filter 10 and the resin are satisfied, the resin is added to the pleated filter 10. The resin is sucked up and no resin remains on the end face of the pleated filter 10. Therefore, as a method for preventing all the resin from being sucked up from the boundary surface between the pleated filter 10 and the upper cap 7 or the lower cap 12, a resin reservoir 22 is provided as shown in FIG. According to this method, since the resin in the resin reservoir 22 is difficult to be sucked up, it is possible to bond and seal the boundary surface between the pleated filter 10 and the upper cap 7 or the lower cap 12. Moreover, as shown in FIG. 4, the resin holding member 23 holding resin is used. The resin holding member 23 can hold the resin in this position by placing it in the filter groove of the cap, for example, as a nonwoven fabric. Can be stopped.
(Example 15)
Example 15 will be described. As described above, when a water hammer or the like is generated, a force is also exerted in a direction in which the cap of the filter unit is pulled away. As shown in FIG. 5, by providing the convex and concave portions 24 on the side surface of the inner wall of the filter groove, it is possible to perform adhesive sealing that is strong against the force in the direction of pulling off the cap of the filter unit.
[0006]
【The invention's effect】
As described above, according to the present invention, a pleated filter and granular activated carbon are used as the main filter, and the filter medium is arranged in the order of the prefilter, the pleated filter, and the activated carbon from the upstream side of the treated water. It is possible to obtain a relatively inexpensive water purifier that is small, has high performance, has a long lifetime, and is highly reliable.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a water purifier of the present invention.
FIG. 2 is an enlarged sectional view showing a pleated filter of the present invention.
FIG. 3 is an enlarged cross-sectional view showing a resin reservoir of the cap of the present invention.
FIG. 4 is an enlarged sectional view showing a resin holding member of the cap of the present invention.
FIG. 5 is an enlarged cross-sectional view showing convex and concave portions of the cap of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inlet side joint 2 Outlet side joint 3 Rubber presser 4 Rubber stopper 5 Body 6 Sealing part 7 by fusion | bonding Upper cap 8 Outer water passage 9 Prefilter 10 Pleated filter 11 Sealing part 12 by adhesion | attachment Lower cap 13 Water inflow direction arrow 14 Water outflow direction arrow 15 O-ring 16 Cage 17 Water collecting pipe 18 Head 19 Activated carbon 20 Support membrane 21 Filter membrane 22 Resin reservoir 23 Resin enclosing member 24 Concavity and convexity

Claims (15)

A case having a raw water inlet and a purified water outlet, a filter medium comprising a prefilter and a main filter loaded inside the case with a gap from an inner peripheral surface of the case, and a holding member for sealing the filter medium and fixing the filter medium in an appropriate position And in the water purifier consisting of a water collecting member with one end communicating with the water purification outlet,
The main filter is composed of a pleated filter and granular activated carbon, and the filter medium is arranged in the order of prefilter, pleated filter, activated carbon from the upstream side of the treated water,
The holding member includes a cap provided at both ends of the main filter and a cage for holding the activated carbon, and forms a pleated filter chamber in which the pleated filter is accommodated and an activated carbon chamber in which the activated carbon is accommodated. A water purifier characterized by The water purifier according to claim 1, wherein the prefilter is made of a nonwoven fabric and is wound around the entire outer surface of the pleated filter. The water purifier according to claim 1 or 2, wherein the case includes a head having a raw water inlet and a purified water outlet and a cylindrical body. The water purifier according to claim 1, wherein the cap has a filter groove on which the pleated filter is mounted and an activated carbon groove that holds the activated carbon. The water purifier according to any one of claims 1 to 4, wherein the pleated filter has a structure in which a filter membrane is sandwiched between support membranes from both sides. 6. The water purifier according to claim 5, wherein the filter membrane is made of a laminate of fibers and having a hole diameter of 10 to 100 [mu] m, and at least two of them are provided. The water purifier according to claim 5 or 6, wherein the support membrane has an average hole diameter of at least 100 µm and a thickness of 10 to 1000 µm. The water purifier according to any one of claims 1 and 5 to 7, wherein the activated carbon chamber has a length longer than that of the pleated filter chamber. The water purifier according to any one of claims 1 to 8, wherein a nonwoven fabric is wound around the entire outer periphery of the water collecting member, and a hole diameter of the nonwoven fabric is smaller than a particle size of the activated carbon. The water purifier according to any one of claims 1 or 5 to 9 , wherein a nonwoven fabric is wound on the entire outer periphery of the cage, and a hole diameter of the nonwoven fabric is smaller than a particle size of the activated carbon. The injection port for injecting the activated carbon is provided in the cap provided above the activated carbon chamber, and after the activated carbon is injected, the injection port is sealed with a rubber stopper. The water purifier according to. The water purifier according to claim 11, wherein a rubber presser for pressing the rubber stopper is provided inside the head. The water purifier in any one of Claim 1 or 5 to 12 which provided the resin reservoir in the bottom part of the filter groove | channel of the said cap. The water purifier in any one of Claim 1 or 5 to 13 which provided the resin enclosure member which encloses resin before hardening in the filter groove | channel of the said cap. The water purifier in any one of Claim 1 or 5 to 14 which provided the uneven | corrugated | grooved part in the inner wall of the filter groove | channel of the said cap.

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