JP2004000989A - Water purification apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water purification apparatus which enables safe and effective bacteriostasis for stagnant water in downstream piping of the water purification apparatus without adding chlorine. <P>SOLUTION: In the water purification apparatus, a silver addition device which adds silver of ≥10μg/l to the downstream piping of the apparatus is attached or a mechanism which adds silver of ≥10μg/l from the water purification apparatus to the downstream piping of the apparatus is disposed. <P>COPYRIGHT: (C)2004,JPO

Description

(4) The present invention relates to a water purification device having a function of removing chlorine, for example, a water purification device that is cut in the middle of piping and installed, among water purification devices used in general households, restaurants, soft drink factories, and the like.

In recent years, due to the progress of tap water pollution, water purifiers have been frequently used for removing chlorine odor and musty odor which cause unpleasant odor, or for removing trihalomethane which has carcinogenic properties. In general households, for example, water purifiers are used close to the faucet, such as a faucet direct connection type, a top sink type, or an undersink type. The extremely short service life is cited as dissatisfaction with these water purification devices. Therefore, in order to solve these users' dissatisfaction, a water purification apparatus in which the size of the water purification apparatus is increased and the instantaneous water flow rate and the total filtration flow rate are increased is considered. These water purifiers become water purifiers that are used by being cut in the middle of piping (for example, see Patent Document 1).
JP-A-9-122636 (FIG. 1)

However, most conventional water purifiers remove chlorine injected into tap water for the purpose of sterilization and purification, so that water after passing through the water purifier removes chlorine and loses sterilization performance. In water purifiers such as faucet direct connection type, top sink type and under sink type where the piping to the faucet is extremely short, the remaining water in the piping after chlorine removal is determined by setting the discharge time every morning, and this water is discarded and used As a result, the bacteria that increase in the residence water in the piping have been treated. However, for example, in the case of a water purifier installed outdoors, the distance from the installation location of the water purifier to the faucet may be several meters or more, and the user is required to discharge the accumulated water in the piping, for example, every morning by the user's manual. However, the user does not always perform sufficient release. Therefore, it is necessary to provide a bacteriostatic function or a sterilizing function to the stagnant water in the downstream piping of the water purification device by some method.However, in the high-quality water supply system installed in buildings, etc., the purified water after passing through the water purification device is required. On the other hand, these bacteriostatic properties have been maintained by adding chlorine at a concentration that is hardly felt by humans. However, in this method of adding chlorine, there is a problem that water purified by removing chlorine once reduces taste due to chlorine odor. The organic matter and chlorine contained in the water may react in a high temperature range, producing a large amount of carcinogenic trihalomethane, which may return to dangerous water.

Therefore, the present invention provides a water purification device that is safe against accumulated water in the downstream piping of the water purification device without adding chlorine, which may cause a decrease in taste or generate a carcinogenic substance due to a rise in temperature. It is intended to provide an effective bacteriostatic method.

た め In order to solve the above-mentioned problems, the present invention provides a water purification device in which a silver addition device for adding 10 μg / liter or more of silver is added to a downstream pipe of the water purification device. Further, the water purification device was provided with a silver addition device for controlling the amount of silver added to the downstream pipe of the water purification device to be 10 μg / L or more and 100 μg / L or less. In addition, a water purifier equipped with a mechanism for adding 10 μg / liter or more of silver from the water purifier to the downstream pipe of the water purifier is adopted. In addition, a water purification apparatus was used in which silver was controlled at 10 μg / L or more and 100 μg / L or less from the water purification apparatus to the downstream pipe of the water purification apparatus.

Fig. 2 shows the measurement results of the sterilization performance of silver against Escherichia coli, which was performed at a designated laboratory specified by the Ministry of Health and Welfare. From FIG. 2, it can be seen that when the silver concentration is 10 μg / liter or more, sufficient sterilization performance is exhibited even for staying water after 24 hours. Silver has been used for tableware and spoons for a long time, has high safety, and has almost no effect on taste. The safety is clear from the fact that Nittan, which has been a favorite for many years, is manufactured by coating a large amount of silver, but from a regulatory perspective, the United States Environmental Protection Agency (EPA) states that The concentration of silver contained is specified to be 100 μg / liter or less based on the type 2 standard. Desirably, following this standard is considered significant in terms of ensuring safety. As described above, there is no problem with the sterilizing performance, taste change, and safety of silver. Therefore, in the water purification device, a silver addition device for adding 10 μg / liter or more of silver to the downstream pipe of the water purification device is added or installed in the water purification device. By incorporating such a mechanism, a bacteriostatic effect can be obtained even in the piping downstream of the water purification device, and safe and excellent taste-purified water can be provided. In addition, if the silver concentration is desirably controlled within the range of 100 μg / liter or less in tap water specified by the United States Environmental Protection Agency (EPA), the safety of the water purification device will be further enhanced.

As described above, according to the present invention, in the water purifier, without adding chlorine that may cause a decrease in taste or generate a carcinogenic substance due to a rise in temperature, the retention of the downstream pipe of the water purifier can be prevented. A safe and effective bacteriostatic method for water can be provided.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of a first embodiment of the present invention, and the first embodiment will be described below. First, 10 tap waters containing harmful substances such as chlorine, musty odor, and trihalomethane pass through one water purifier. Activated carbon, nonwoven fabric, or hollow fiber membranes are usually used in water purifiers to decompose or remove turbidity components and chemical substances such as chlorine in water. The 10 tap water purified by one water purifier is divided into two directions, a system guided to the silver elution system downstream of the one water purifier and a system directly flowing to the faucet. The silver elution system is controlled entirely by 9 control units. The control unit 9 is provided with an instantaneous flow rate of purified water 11 flowing in the direction of the faucet measured by the flow meter 8. The control unit 4 determines the amount of the silver solution 14 stored in the silver elution tank and determines the amount 7. The discharge amount of the 14 silver solution is instructed to the fixed amount discharge pump, and the 14 silver solution is discharged from the 7 fixed amount discharge pump to the purified water side to add appropriate silver to the 11 purified water. In this example, since a sensor for detecting the silver concentration of the 14 silver solution is not added, the silver concentration of the 11 purified water is regarded as a constant value of the 14 silver solution, and the silver concentration of the 14 silver solution is determined only by the flow rate of the 11 purified water. It is controlled by adding a solution. A 5 silver level detector is attached to the 4 silver elution tank, and sends the water level information of the 4 silver elution tank to 9 control units. The 9 control unit gives a command to the 2 electromagnetic valves when the water level of the 4 silver elution tank falls below a certain value, and the 2 electromagnetic valves automatically adjust the valves to supply purified water to the 4 silver elution tank.

Here, the mechanism of silver elution will be described in detail. The inside of the 4-silver elution tank contains finely divided solid silver oxide and purified water. When a solid silver compound is immersed in water for an extremely long time, silver equivalent to its saturated solubility can be eluted in water. However, in this example, since the 14 silver solution stored in the 4 silver elution tank is added to the 11 purified water as described above, the 14 silver solution is used in a short time depending on the use situation of the user, Purified water to make the 14 silver solution may be replenished and reduce the concentration of the 14 silver solution. In this example, since the means for detecting the silver concentration of the 14 silver solution is not taken as described above, it is necessary that the silver concentration of the 14 silver solution can be regarded as constant. Therefore, it is necessary to stabilize the silver concentration of the 14 silver solution in a relatively short period of time, and for that purpose, it is necessary to dissolve silver rapidly to the saturation solubility. Therefore, ultrasonic waves are applied to the 4-silver elution tank containing the solid silver compound and purified water to forcibly vibrate, thereby dissolving silver efficiently. When the silver concentration of the 14 silver solution in the 4 silver elution tank reaches the saturation solubility of silver oxide, it does not increase any more even when vibration is applied, and the silver concentration is stabilized at a certain upper limit concentration. Therefore, also in the system shown in this example, a 14 silver solution having a stable silver concentration can be added to 11 purified water.

FIG. 3 shows a schematic cross-sectional view of the configuration of the second embodiment of the present invention. FIG. 3 shows a so-called out-in type water purifier in which 18 silver-impregnated activated carbon is put as a filter material in 15 cases. The water to be treated (not necessarily tap water) entering from the 16 tap water inlet passes between the 15 housings and the 20 partitions and proceeds into the activated carbon impregnated with 18 silver, and the 21 central water channel provided in the center To 17 through a purified water outlet. Conventionally, activated carbon impregnated with silver has been used to impart a bacteriostatic action to the inside of a water purifier, particularly to an activated carbon portion where microorganisms are easily generated. Therefore, normally, silver is supported on activated carbon, and silver having a weight ratio of about 0.1% to activated carbon is mixed in the activated carbon portion. In this state, silver which can be dissolved in the downstream pipe of the water purifier is at most 1 to 1. Only 3 μg / liter. Therefore, the conventional amount of silver contamination cannot provide a sufficient bacteriostatic effect on the downstream pipe of the water purifier. In the present example, the amount of silver mixed into the activated carbon part was increased, and silver having a weight ratio of 4% or more with the activated carbon was mixed using activated carbon. As a result, the silver concentration of 120 μg / liter was detected immediately after passing water from the state where silver of 1 to 3 μg / liter was conventionally eluted in the downstream pipe of the water purifier, and thereafter the silver concentration gradually decreased. It was confirmed that water could be stably passed at a value of about 20 μg / liter.

Here, the elution of silver of 120 μg / liter even immediately after passing water exceeds 100 μg / liter or less recommended by US EPA. Desirably, a silver concentration of 100 μg / liter or less is eluted immediately after the water is passed. As a method, silver having a weight ratio of 4% or more with activated carbon and loaded on activated carbon before filling into a water purifier is used. The steps were washed with clean water, dried and filled. As a result, it was confirmed that the silver concentration was 80 μg / liter in the downstream pipe of the water purifier immediately after the passage of water. Further, as a method of shortening the time required for washing the activated carbon carrying silver before filling with activated carbon or controlling the silver concentration immediately after starting the passage of water, raising the temperature of purified water used for washing is also an effective means. It was confirmed.

Outline of water purification system with silver addition device Escherichia coli bactericidal action data by silver Outline of configuration of water purifier with silver elution function using silver activated carbon

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Water purifier 2 Solenoid valve 3 Check valve 4 Silver elution tank 5 Water level detection device 6 Ultrasonic vibration device 7 Discharge pump 8 Flow meter 9 Control unit 10 Tap water 11 Purified water 12 Control signal 13 Detection signal 14 Silver solution 15 Case Body 16 Tap water inlet 17 Purified water outlet 18 Silver-impregnated activated carbon 19 Water flow 20 Partition 21 Central waterway

Claims (4)

Of the water purifiers that have the function of removing chlorine,
A water purifier characterized by adding a silver addition device for adding 10 μg / liter or more of silver to a downstream pipe of the water purifier. In the scope of claim 1,
A water purification device in which silver added to a downstream pipe of the water purification device is controlled to 10 μg / liter or more and 100 μg / liter or less. Of the water purifiers that have the function of removing chlorine,
A water purifier equipped with a mechanism for adding 10 μg / L or more of silver from a water purifier to a downstream pipe of the water purifier. In the scope of claim 3,
A water purification device in which silver added to the downstream side of the water purification device is controlled to 10 μg / liter or more and 100 μg / liter or less.

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