JPH07155750A - Hot-water sterilization method for water purifier - Google Patents

Abstract

PURPOSE:To enable to introduce hot water into a filtering part and to sterilize an interior of a water purifier, in the water purifier housing a filtering part formed with active carbon and a hollow yarn membrane. CONSTITUTION:Hot water at a specified temp. is passed for the time in accordance with the temp. in the same manner as the water passing method in normal water purification, as the hot water introducing method. Besides, in order to practice more conveniently, a stop valve is provided between a hot water distributing pipe and a feed water intake of the water purifier and the stop valve is automatically turned on and off by a timer and the hot water is fed to the water purifier at the time of opening the stop valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purifier used for purifying tap water and the like. More specifically, the present invention relates to a method for sterilizing hot water of a water purifier that prevents water that has been once purified from being re-contaminated by bacteria or the like.

[0002]

2. Description of the Related Art In recent years, a water purifier having a filtration mechanism in which a filter using a filtration membrane having fine pores such as a hollow fiber membrane is used in combination with activated carbon has attracted attention and has been widely used for purification of tap water. .

In such a filter, the hollow fiber membrane is converged, and the converging end is fixed by a potting material such as polyurethane resin so as not to block the open end of the hollow fiber membrane, whereby the hollow portion of the hollow fiber membrane is fixed. Is airtightly partitioned and is fixed to the cylindrical case body, and the filtration portion is formed in a state of being connected to the activated carbon layer.

In this filtration section, residual carbon in tap water, other odorous components, organic substances, etc. are removed by activated carbon, and iron rust and colloidal components, bacteria etc. which are difficult to remove only by chlorine sterilization are provided by the hollow fiber membrane layer. Removal is taking place.

In addition, as a tap for supplying tap water,
There is a widespread type in which a hot water supply from a hot water supply pipe of a gas type or an electric water heater can be provided together with a drinking water pipe under a sink.

[0006]

In this way, the purified water purified by the filter section and staying in the filter section and the water pipe connected to the filter section has the chlorine component for sterilization introduced into tap water. Almost removed. Therefore, if you touch the water outlet of the water purifier with an unsanitary hand, or if the water droplets adhere to the water outlet of the water purifier when you are not using it at the place where the water purifier is installed and when you wash dishes or wash dirt, etc. , If the water purifier is left unused for several days, bacteria may grow inside the water purification pipe and the water purification outlet may be contaminated.

Therefore, when the conventional water purifier is not used for a long time and is reused, a certain amount of purified water is discarded and the contaminated accumulated water is removed before use.
However, when the degree of pollution is high, a small amount of waste water immediately reproduces the pollution.

On the other hand, as the industrial sterilization means, a method using a chemical agent, a method using an ultraviolet germicidal lamp, a method using ozone, a gas method using ethylene oxide or the like, a method using radiation such as γ rays, a method using high pressure steam, etc. However, it is not practical as a sterilizing method for a water purifier for supplying drinking water in general households.

From the above, a method of sterilization with warm water is mentioned as a relatively safe and practical method at home. In this case, it may not be possible to completely sterilize it for industrial use, but it cannot be used in a water purifier, but since many contaminating bacteria easily grow at relatively low temperatures, 50 ° C to 8 ° C.
It is effective in sterilization with warm water at a relatively low temperature of 0 ° C.

As an attempt to prevent bacterial contamination of the water purifier by sterilization with warm water, there is an attempt to sterilize only the water passage after passing through the filtration section (Japanese Patent Laid-Open No. 31480/1993) or a filtration section mainly composed of activated carbon. An attempt of hot water sterilization for a water purifier (Japanese Patent Laid-Open No. 4-243591) and the like are shown.

However, the former sterilization of only the water passage after passing through the filtering portion is not sufficient for preventing pollution, and there is a concern that the accumulated water in the piping portion may be contaminated when hot water is not passed. On the other hand, in the latter water purifier having a filter section mainly composed of activated carbon, chlorine which is put in tap water for the purpose of disinfection is removed, so that various bacteria propagate in the filter section. Although sanitary purified water can be obtained immediately after sterilization with warm water, there is a possibility that purified water will always be contaminated by bacterial growth when non-warm water is passed. The present invention provides a reliable and simple sterilization method for a water purifier without causing the above-mentioned inadequacies.

[0012]

The gist of the present invention is to sterilize the inside of a water purifier by introducing hot water into the filter in a water purifier having a filter formed of activated carbon and a hollow fiber membrane. It is a hot water sterilization method for a water purifier characterized by:

As the water purifier used in the present invention, a material that can be used in a temperature range of 50 to 80 ° C. is selected as a material used for the member, and it can be connected to a commonly used faucet. It can be either a direct faucet direct connection type or a stationary type, and an undersink type that can be installed in the pipe section under the sink will do as long as hot water can be supplied from the same faucet.

As a faucet for installing a water purifier, hot water from a hot water pipe of a gas or electric water heater can be supplied together with a drinking water pipe, and hot water of a predetermined temperature can be obtained by mixing hot water and tap water. A hot and cold water mixing faucet that can be supplied is desirable. However, when the drinking water supply faucet and the hot water supply faucet are installed individually on the facility, for the faucet direct connection type and the stationary type, a water purifier is usually installed in the drinking water supply faucet and the sterilization method of the present invention. It is also possible to move to the hot water supply faucet only when performing.

In addition, as a method of introducing hot water, in the case of a hot and cold water mixing faucet as described above and in the case of a single hot water supply faucet, hot water of a predetermined temperature is supplied to normal purified water for a time corresponding to the temperature. Water may be passed in the same manner as the method of passing water. Furthermore, for easier implementation, an opening / closing valve is provided between the hot water supply pipe and the raw water inlet of the water purifier, and the opening / closing valve is automatically opened / closed by a timer, and hot water is supplied to the water purifier when the opening / closing valve is opened. It is also possible to install a device adapted to do so.

As the hot water flow conditions, the higher the temperature, the shorter the time of sterilization is possible, but it is desirable to select the temperature in consideration of safety and heat resistance of the water purifier. More specifically, as is clear from the results in Table 1, it is about 30 minutes at 50 ° C, 3 to 5 minutes at 60 ° C, 1 to 3 minutes at 70 ° C, and 80 minutes.
It is possible to sterilize by passing water for 1 minute at ℃, but it may be necessary to extend the time depending on the capacity of the water purifier.

[0017]

[Table 1]

The water passage time during hot water sterilization is 30 minutes or more, which is not practical, and therefore the lower limit of the hot water temperature is preferably about 50 ° C. In addition, using hot water of 80 ° C or higher at home poses a safety problem, and in order to use hot water of high temperature, more expensive heat-resistant materials must be used, which is not practical. The upper limit of the hot water temperature is preferably around 80 ° C. From the above, as the sterilizing hot water, 50 to 80 ° C is desirable.

Further, in such a temperature range, various hollow fiber membranes made of polyolefin, polysulfone, acetate and the like can be mentioned as the hollow fiber membrane material, and among them, chemical stability, microbial stability and easy handling are mentioned. Therefore, a polyolefin-based porous membrane is preferable. As the polyolefin, a polymer or copolymer mainly composed of one or more monomers selected from the group consisting of ethylene, propylene, 4-methyl-1-pentene and 3-methyl-1-butene,
Or the thing using these fluorine compounds is mentioned.

[0020]

The hot water sterilization method for a water purifier of the present invention can be used as a preventive measure against bacterial contamination that may occur during continuous use of the water purifier. It becomes possible to take measures.

[0021]

EXAMPLE An example in which the sterilizing method of the present invention is actually carried out by using a water faucet direct connection type water purifier will be specifically described below. Example 1 A water purifier intentionally contaminated under the environment of 30 ° C. × 90 RH% (Mitsubishi Rayon Co., Ltd.) in the same manner as the water purifier used in Table 1.
Table 2 and Table 3 show the results of examining the effect of sterilization with hot water in an actual machine using a cleansed product manufactured by Kurinsui. Table 2 shows the results when hot water at 60 ° C was passed, and Table 3 shows the results when hot water at 70 ° C was passed. The confirmation of the sterilization method was performed by examining the viable cell counts of the contaminated purified water initial flow, the purified water after passing a predetermined amount of warm water, and the purified water initial flow after being left at room temperature for 24 hours. As for the method for measuring the viable cell count, the heterotrophic bacteria test was used as in Table 1.

[0022]

[Table 2]

[0023]

[Table 3]

As a result of carrying out warm water sterilization on the faucet direct connection type washing machine in this manner, it was found that a sufficient sterilization effect can be obtained if water is passed for a time corresponding to the temperature at which water is passed.

[0025]

EFFECT OF THE INVENTION The present invention is a method for sterilizing hot water in a water purifier, characterized in that the inside of the water purifier is sterilized by using hot water in the water purifier having a built-in filter formed of activated carbon and a hollow fiber membrane. In contrast to the usual industrial sterilization method, it is possible to sterilize by ordinary households by an easy and simple means.

Claims (2)

[Claims] 1. A water purifier with a built-in filter formed of activated carbon and a hollow fiber membrane, wherein hot water is introduced into the filter to sterilize the inside of the water purifier. Sterilization method. 2. The method according to claim 1, wherein the temperature of the hot water is 50 ° C. to 80 ° C.