JPH07185530A - Automatic control system for chlorine concentration - Google Patents

Abstract

PURPOSE:To maintain chlorine concentration at the absolute minimum when water distributed to a pass passing through an active carbon filter and a pass not passing it is distributed through a three-way valve by controlling the opening degree of the three-way valve according to the measured value of the concentration of free chlorine in water. CONSTITUTION:A pass for fed water is divided into a pass A passing through an active carbon filter 1 and a pass B not passing through it, and after that, they are joined, and a three-way valve 2 is installed at the junction. As the three-way valve 2, that having the valve relationship between a straight direction A and a bypass direction B being an equal percentage characteristic is used. Water joined through the three-way valve 2 is distributed to each house. In this case, a part of the distributed water is drawn out and introduced into a residual chlorine meter 3 to measure the residual chlorine. According to the measured value, the opening degree of the two passes of the three-way valve 2 is automatically controlled through an indicating controller 4. By regulating the quantity of water passing through the active carbon filter 2, the chlorine concentration is controlled in a desired range of concentration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic chlorine concentration control system for tap water and a comprehensive tap water purification system.

[0002]

2. Description of the Related Art In recent years,
Demand for safe and delicious water is increasing among general consumers.

Therefore, various methods for removing oxygen, which causes red water, and chlorine, which causes odor of chlorine, from tap water have been studied.

Chlorine is added to the water purification plant for the purpose of sterilization.
Need a chlorine concentration of. However, at the same time, since chlorine is a component that affects the taste and smell of water, it is desired that its content be suppressed to the necessary minimum.

As one of the methods for purifying water, hollow fiber membranes are often used for removing gases such as oxygen, which causes red water, from the convenience of handling.

The inventor of the present invention has also disclosed a gas-liquid separator using a hollow fiber membrane in JP-A-3-47520 and JP-A-3-21320.
No. 188 or Japanese Patent Application No. 4-248945, it is possible to remove not only the oxygen causing the generation of red water but also the carcinogen trihalomethane, and further removal of these hydrophobic gases. Provided is a device that is efficient and easy to maintain and manage.

However, since chlorine is a hydrophilic gas, chlorine cannot be removed by the hollow fiber membrane. It is recognized that adsorption by activated carbon is the most effective method for removing chlorine, and a chlorine concentration control system using an activated carbon filter is considered. A typical example is that a housing is provided as shown in FIG. 4, water is evenly distributed in two passages, that is, a passage passing through an activated carbon filter ... A and a passage not having an activated carbon filter attached, and then joined. It is a thing.

However, in the above case, the chlorine concentration in tap water is uniformly halved, so that when the chlorine concentration is already sufficiently low, it falls below the standard value. As described above, conventionally, it has been extremely difficult to control the content of chlorine.

Therefore, it is an object of the present invention to provide a chlorine control system in which it is easy to control the chlorine concentration in tap water to the minimum necessary level, and therefore, it is possible to provide delicious water with no odor of chlorine. Further, it is an object of the present invention to provide a water purification system in which red water is less likely to be generated and trihalomethane, which is a carcinogen, is reduced and safe and delicious tap water can be provided.

[0010]

The present inventor has completed the present invention described below as a result of intensive studies in accordance with the above object.

That is, according to the present invention, the water distributed from the water supply pipe to the flow path passing through the activated carbon filter (straight direction) and the flow path not passing the activated carbon filter (passing direction) has the equal% characteristic. This is a chlorine removal method that merges and distributes water with a three-way valve, measures the concentration of free chlorine in the water that is distributed, and automatically determines the valve opening ratio between the straight direction and the bypass direction of the three-way valve according to the measured value. The chlorine concentration automatic control system is characterized in that the chlorine concentration is adjusted by controlling the mixing ratio of water from the two flow paths by controlling the flow rate.

The present chlorine concentration automatic control system can maintain the chlorine concentration in the water tap at the end at 0.1 ppm to 0.3 ppm, and can provide water that has a bactericidal effect and does not give rise to an odor of chlorine.

Further, according to the present invention, water whose chlorine concentration is controlled by the above-mentioned system is passed through a contaminant removal filter, if necessary, and then a gas-liquid separation device, that is, a hollow fiber membrane made of a polymer substance is used. A large number of units arranged in parallel are arranged in the container, and water is circulated from one end of the hollow fiber membrane to the other end to create a negative pressure in the container and remove hydrophobic gas through the hollow fiber membrane. It is intended to provide a comprehensive water purification system in which oxygen, trihalomethane, etc. are reduced by passing through the device.

[0014]

The function of the present invention is that the opening ratio of the three-way valve is automatically proportionally controlled according to the value measured by the residual chlorine meter, and the flow path passes through the activated carbon filter with chlorine removal ability ... A and the bypass that does not pass through the activated carbon filter. The ratio of the amount of water from the road B is selected by proportional control. That is, when the chlorine concentration in the water that has undergone a series of purification treatment exceeds the desired range, a large proportion of the water from the flow path A passing through the activated carbon filter is distributed, and conversely the chlorine concentration is the minimum required. If it is below the limit, try to distribute a large amount of water from the bypass route B.

According to the present invention, heretofore impossible,
As described above, the ratio of the amounts of water in the channel A and the channel B can be arbitrarily changed, so that the desired chlorine concentration can be always maintained.
Therefore, it is possible to provide tasty water that can be kept in a concentration range that is the minimum necessary for the bactericidal effect, preferably 0.1 to 0.3 ppm, which is an extremely narrow concentration range, and does not have an odor of chlorine. If it is less than 0.1 ppm, it is recognized that the bactericidal action is insufficient under the current legislation, and conversely 0.3
If it exceeds ppm, a odor of chlorine will be felt. The Ministry of Health and Welfare Delicious Water Committee also announced the same effect.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG. The flow path of the supplied water is divided into a flow path ... A that passes through the activated carbon filter ... 1 and a bypass path ... B that does not pass through, and then merges. A three-way valve 2 is provided at the confluence to adjust the amount of water from each flow path. As the three-way valve 2, a valve whose straight direction A and bypass direction B have an equal% characteristic is used.

The water joined by the three-way valve is distributed to each house, and a part of the water is used for measuring the chlorine concentration and the residual chlorine meter. The residual chlorine meter is a chlorine (C) that is not combined with organic substances among the chlorine added for sterilization.
l ₂ ), hypochlorous acid (HClO), hypochlorite ion (ClO ⁻ ), and the like, which can measure chlorine in a free state which causes a chlorine odor without leaking.

In accordance with this measured value, the opening ratio of the two flow paths of the three-way valve 2 is automatically controlled through the indicator controller 4 and the chlorine concentration is adjusted by adjusting the amount of water passing through the activated carbon filter 1. Can be controlled within a desired concentration range.

As the three-way valve of the present invention, for example, a valve actuator SKD62 made by Tokimec can be applied, and its structure is shown in FIG. When the valve stem 21 is pulled up, the inner valve 22 is raised and the flow rates in the straight direction A and the bypass direction B are adjusted according to the amount of movement.

As the residual chlorine meter of the present invention, for example, a FRD-II type residual chlorine meter manufactured by Ohyalux Co., Ltd. can be applied. The device uses a rotating electrode polarographic method as a measurement principle, and a voltage (applied voltage) is applied between the indicator electrode (rotating electrode) and the counter electrode to electrolytically reduce free chlorine,
This is a device for measuring the current (diffusion current) flowing at this time to obtain the concentration of free chlorine.

Based on the value measured by the residual chlorine meter, by controlling the opening ratio of the inner valve 22 by moving the valve stem 21 of the three-way valve up and down, the amount of water passing through the activated carbon filter can be adjusted and is always constant. It is possible to provide delicious water having a chlorine concentration of a certain amount and having no chlorine odor.

As described above, the chlorine concentration in the water tap at the end is preferably 0.1 to 0.3 ppm,
For this purpose, the setting range of the support adjuster 4 is preferably narrower than this.

The present invention can be used as a comprehensive water purification system by combining other devices for water purification. For example, there is a water purification system shown in FIG.

[0024] A plurality of hollow fiber membranes made of a high molecular weight substance having a controlled chlorine concentration are arranged side by side in a container, and water is circulated from one end to the other end of the hollow fiber membranes. If a negative pressure is applied inside the container, and a hydrophobic gas is permeated and removed through the hollow fiber membrane, if it passes through a gas-liquid separation device ... 8, oxygen that causes the generation of red water and chlorine in the water purification plant are added to the water supply process. It is possible to reduce the carcinogen trihalomethanes generated during the period.

In order to prevent the occurrence of pinholes or contamination of the hollow fiber membrane, it is preferable to pass through the foreign matter removal filter 7 before passing through the gas-liquid separation device to remove the mixed fine dust. In particular, two different types of filters within the range of 1 to 15 μm, such as 12 μm and 5 μm.
It is preferable to treat with two kinds of filters such as m or 10 μm and 3 μm.

With the above-mentioned water purification system, it is possible to provide more delicious and safe water without feeling the smell of chlorine and the taste of iron rust.

As the gas-liquid separation device, Japanese Patent Application Laid-Open No. 3-47520 and Japanese Patent Application Laid-Open No. 3-47520 previously disclosed by the present inventor are disclosed.
The apparatus described in Japanese Patent Laid-Open No. 213188 or Japanese Patent Application No. 4-248945 is preferable because the gas removal efficiency is good and maintenance of the apparatus is easy.

The automatic control of chlorine concentration according to the present invention will be described in more detail with reference to the following examples.
However, the present invention is not limited to this.

[0029]

Example 1 In FIG. 1, the measurement range of the residual chlorine meter ... 3 is set to 0 to 1 mg / L. At this time, a signal of 4 mA is output when the residual chlorine concentration is 0, and the residual chlorine concentration is 1 mg /
When L, a signal of 20 mA is output.

The indicator adjuster 4 receives this signal and calculates it to indicate the residual chlorine concentration. At the same time, a voltage signal for adjusting the opening of the three-way valve is output according to the set value (residual chlorine concentration) and the proportional band. Here, the set value is 0.20 mg /
L, if the proportional band is set to 5%, the flow path that passes through the activated carbon ... 1 when the measured residual chlorine concentration is 0.20 mg / L ...
The flow rates in A and the bypass path ... B are 50% each.

The residual chlorine concentration measured is 0.18 mg / L
When it becomes, the bypass side of the three-way valve ... B is opened more and the flow rate becomes 55%, and the activated carbon side ... A is throttled to 45%. On the other hand, when the measured value becomes 0.22 mg / L, the activated carbon side ... A of the three-way valve is greatly opened and the flow rate is 55%, and the bypass side ... B is throttled to 45%.

The residual chlorine concentration set by the proportional operation as described above is 0.1 to 0.3 mg / L at the water tap end.
Can be held at (ppm).

The diameters of the activated carbon side ... A and the bypass side ... B were 25 A each. The flow rate of this diameter is about 103 L /
min, the flow rate in the pipe was 2.5 to 3 m / sec. For this reason,
Even if one side is fully closed, the flow rate is secured. Since at least one of the activated carbon side and the bypass side is always open and water flows in the pipe, stagnation of water does not decrease and fresh water can always be provided.

[0034]

According to the present invention, since the chlorine concentration in tap water can be automatically and accurately controlled, it is possible to suppress the chlorine concentration to the minimum necessary for the bactericidal effect, and it is delicious without smelling chyle. Water can be provided.

Furthermore, the water purification system of the present invention can stably provide delicious and safe water.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of a chlorine automatic control system of the present invention.

FIG. 2 is a vertical sectional view showing an example of a three-way valve applicable to the chlorine automatic control system of the present invention.

FIG. 3 is a flowchart showing one embodiment of the water purification system of the present invention.

FIG. 4 is a flow chart showing a conventional chlorine concentration control system for tap water.

[Explanation of symbols]

 1 ... Activated carbon filter 2 ... Three-way valve 3 ... Residual chlorine meter 4 ... Indicator regulator 5 ... Foreign matter removal filter 6 ... Pressure reducing valve 7 ... Flow meter 8 ... Gas-liquid separation device 21 ... Valve stem 22 ... Inner valve 23 ... Spring 24 ... Gland packing

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C02F 1/58 L

Claims (4)

[Claims] 1. A three-way valve having an equal% characteristic for water distributed from a water supply pipe to a flow passage (straight direction) passing through an activated carbon filter and a flow passage (passage direction) not passing through an activated carbon filter. A chlorine removal method that combines and distributes water, measures the concentration of free chlorine in the water that is distributed, and automatically controls the valve open ratio between the three-way valve straight direction and the bypass direction according to the measured value. The chlorine concentration automatic control system is characterized in that the chlorine concentration is adjusted by adjusting the mixing ratio of water from the two flow paths. 2. The chlorine concentration in the water tap at the end is 0.1 p.
The chlorine concentration automatic control system according to claim 1, which is maintained at pm to 0.3 ppm. 3. A container in which a plurality of units of water containing a chlorine concentration controlled by the system according to claim 1 are further disposed in a gas-liquid separator, that is, a plurality of polymer-made hollow fiber membranes are arranged in parallel. The water purification system is characterized in that water is circulated from one end of the hollow fiber membrane to the other end thereof, and the inside of the container is subjected to a negative pressure to pass through a device for permeating and removing the hydrophobic gas through the hollow fiber membrane. 4. The water, the chlorine concentration of which is controlled by the system according to claim 1, is passed through a contaminant removal filter before being passed through the gas-liquid separation device.
Water purification system described.