JP7089434B2 - Residual chlorine detection device and residual chlorine detection method - Google Patents

Description

The present disclosure relates to a residual chlorine detection device for detecting free residual chlorine in tap water and a method for detecting residual chlorine.

Conventionally, as this kind of residual chlorine detection method, a method of immersing a pair of electrodes having different ionization tendencies in tap water and detecting free residual chlorine based on the voltage generated between the electrodes is known (for example,). See Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-114376 (paragraph [0008])

By the way, in the above-mentioned conventional residual chlorine detection method, a technique has been developed in which the detection accuracy is improved by making it less susceptible to the influence of inclusions other than free residual chlorine in tap water. However, the effect is not sufficient, and there is a need to develop a technique capable of detecting free residual chlorine with higher accuracy than before.

The invention of claim 1 made to solve the above problem is a residual chlorine detecting device for detecting free residual chlorine in tap water, and removes the free residual chlorine from tap water discharged from a water pipe. A removal processing unit to be performed, a pair of electrodes having different ionization tendencies, a first voltage generated between the pair of electrodes in a state of being immersed in the treated tap water having been removed, and the removal. A measuring unit that detects the second voltage generated between the pair of electrodes when the pair of electrodes is immersed in untreated untreated tap water, and the free residual chlorine in tap water from the second voltage. It is a residual chlorine detection device including a difference calculation unit for obtaining a difference voltage by subtracting a voltage component due to an inclusion other than the above first voltage based on the first voltage.

According to the invention of claim 2, the removal processing unit has a storage unit in which tap water discharged from the water pipe is stored for a predetermined reference time or longer, and the removal treatment is performed by storing the tap water for the reference time or longer. The residual chlorine detection device according to claim 1, wherein the first voltage and the second voltage are detected in a state where the pair of electrodes is fixed to the storage portion.

The invention according to claim 3 is the residual chlorine detection according to claim 2, wherein the difference calculation unit obtains the difference voltage from the second voltage and the first voltage detected immediately before the detection of the second voltage. It is a device.

The invention of claim 4 is a drain port that drains tap water from the storage section and is opened and closed by a drain valve, and a water supply port that supplies tap water to the storage section and is opened and closed by a water supply valve. And a valve control unit that controls the drainage valve and the water supply valve so that the storage unit is always maintained in a substantially full state including when the treated tap water is replaced with the untreated tap water. The residual chlorine detection device according to claim 2 or 3.

In the invention of claim 5, the amount of water supplied from the water supply port when the water supply valve is fully open is larger than the amount of drainage from the drain port when the drainage valve is fully open, and the valve control is performed. The unit is the residual chlorine detection device according to claim 4, wherein both the drain valve and the water supply valve are fully opened when the inside of the storage portion is replaced with the untreated tap water.

The invention of claim 6 is the residual chlorine detection device according to claim 1, further comprising a stirrer for stirring tap water in the reservoir.

The invention of claim 7 is the residual chlorine detection device according to claim 1, wherein the upper surface of the storage portion is open.

The invention of claim 8 is a method for detecting free residual chlorine in tap water, which tends to ionize the treated tap water from which the free residual chlorine has been removed from the tap water discharged from the water pipe. Immerse a pair of different electrodes to detect the first voltage generated between the electrodes, and immerse the pair of electrodes in untreated tap water that has not been removed and generate between the electrodes. The second voltage is detected, and the voltage component due to the inclusions other than the free residual chlorine in tap water is subtracted from the second voltage based on the first voltage to obtain the differential voltage, and the differential voltage is used to obtain the differential voltage. This is a residual chlorine detection method for detecting free residual chlorine.

In the invention of claim 9, the removal treatment is performed by storing tap water discharged from the water pipe in a storage unit for a predetermined reference time or longer, and the pair of electrodes is fixed to the storage unit. The residual chlorine detection method according to claim 8, wherein the first voltage and the second voltage are detected.

The invention of claim 10 is the residual chlorine detection method according to claim 9, wherein the differential voltage is obtained from the second voltage and the first voltage detected immediately before the detection of the second voltage.

The invention according to claim 11 is the residual chlorine detection method according to claim 9 or 10, wherein the storage portion is always maintained in a substantially full state including when the treated tap water is replaced with the untreated tap water.

In the inventions of claims 1 and 8, a pair of electrodes is immersed in tap water which has been treated to remove free residual chlorine, and the first voltage is detected. Then, the voltage component due to the inclusions other than free residual chlorine is subtracted from the second voltage detected by immersing the pair of electrodes in untreated tap water based on the first voltage, and the differential voltage is obtained. Therefore, the differential voltage is obtained. It is possible to detect free residual chlorine with higher accuracy than before.

In the inventions of claims 2 and 9, since the pair of electrodes is fixed to the storage portion where the treated tap water and the untreated tap water are stored, it is easy to make the detection conditions of the first voltage and the second voltage uniform. This also makes it possible to detect free residual chlorine with high accuracy.

The difference voltage may be obtained from the second voltage and the first voltage detected immediately after that, or as in the inventions of claims 3 and 10, the second voltage and the first voltage detected immediately before the second voltage. You may ask from. In the former case, it takes a removal time to remove the free residual chlorine between the detection of the first voltage and the second voltage, and in the latter case, it takes a time to replace the tap water. Usually, since the replacement time can be shortened as compared with the removal time, according to the inventions of claims 3 and 10, it becomes easy to make the detection conditions of the first voltage and the second voltage uniform.

Electrodes have different surface conditions depending on whether they are in contact with air or water, which can be a disturbing factor for voltage detection. On the other hand, in the inventions of claims 4 and 11, since the storage portion is always maintained in a substantially full state including the time when the treated tap water is replaced with the untreated tap water, the disturbance of the first voltage and the second voltage is caused. Suppressed detection is possible.

According to the configuration of claim 5, the reservoir can be maintained in a full state and the treated tap water can be replaced with untreated tap water simply by fully opening both the drain valve and the water supply valve.

According to the configuration of claim 6, the removal of the residual chlorine detection device can be promoted by stirring the tap water in the storage unit with a stirrer. When the voltage is detected, it is preferable to stop the stirrer to stop the flow in the tap water.

In the configuration of claim 7, since the upper surface of the storage portion is open, the stored tap water comes into contact with air to promote the removal of free residual chlorine.

Conceptual diagram of the residual chlorine detection device of the first embodiment Control program flowchart Control program flowchart Conceptual diagram of the residual chlorine detection device of the second embodiment Conceptual diagram of the residual chlorine detection device of the third embodiment

[First Embodiment]
Hereinafter, embodiments of the residual chlorine detection device 10 and the residual chlorine detection method shown in FIGS. 1 to 3 will be described. FIG. 1 conceptually shows the residual chlorine detection device 10 of the present embodiment. The residual chlorine detection device 10 is provided with a storage portion 11 having a tank structure with an open upper surface. An outlet of the water pipe 12 is arranged above the storage unit 11. The water pipe 12 is branched from the water pipe 13 which is the main pipe of the water pipe network, and the discharge port of the water pipe 12 is the water supply port 12A for the storage unit 11. Further, the water supply port 12A is opened and closed by the water supply valve 12V. The water supply valve 12V is provided with, for example, a solenoid as a drive source, and can be switched between a fully open state and a fully closed state.

A drainage port 11A is provided in the lower part of the storage unit 11 and is opened and closed by a drainage valve 11V. The drain valve 11V also has a solenoid as a drive source and can be switched between a fully open state and a fully closed state. In addition, the amount of water supplied from the water supply port 12A when the water supply valve 12V is opened is slightly larger than the amount of drainage from the drain port 11A when the drain valve 11V is opened when the storage unit 11 is full. It has become. One or both of the water supply valve 12V and the drainage valve 11V may be used as a flow rate control valve capable of controlling the flow rate.

A drain pan 14 is provided below the reservoir 11. Then, the tap water overflowing from the storage unit 11 and the tap water discharged from the drain port 11A are received by the drain pan 14. The tap water received in the drain pan 14 is discharged to sewage or the like from, for example, the discharge port 14A of the drain pan 14.

The storage unit 11 is provided with a stirrer 15. The stirrer 15 is provided with, for example, a motor as a drive source, and has a rotary blade 15A submerged in tap water in a filled storage unit 11. Further, the drive source is arranged above the storage unit 11 by a bracket (not shown). Then, for example, the rotary blade 15A rotates at a low speed such that tap water does not foam, and the tap water is agitated.

A pair of electrodes 16A and 16B are fixed to the storage unit 11 and immersed in tap water in the storage unit 11. The electrodes 16A and 16B are metals having different ionization tendencies, and one electrode 16A is composed of a metal (for example, platinum, iridium, gold or palladium) that easily reacts with free residual chlorine, while the other. The electrode 16B is made of a metal that does not easily react with free residual chlorine (for example, SUS316, SUS316L, SUS430, tungsten, tantalum, titanium, molybdenum or zirconium).

The pair of electrodes 16A and 16B are connected to the measuring unit 17, and the voltage generated between the electrodes 16A and 16B is detected by the measuring unit 17.

The measuring unit 17 is provided with a resistance element connected between the electrodes 16A and 16B, and is configured to detect the voltage between both terminals of the resistance element. A switch is provided between the electrodes 16A and 16B so that the inclusions other than the free residual chlorine in the tap water do not disappear, and the electrodes 16A and 16B are disconnected except when the voltage is detected. May be good.

The timing of voltage detection by the measuring unit 17 and the timing of operation of the above-mentioned agitator 15, the water supply valve 12V, and the drainage valve 11V are controlled by the control unit 20. The control unit 20 has a microcomputer and a storage unit, and the storage unit stores the control program PG1 shown in FIGS. 2 and 3. Then, when the residual chlorine detection device 10 is started, the control program PG1 is executed by the microcomputer, and each part is controlled as follows.

That is, as shown in FIG. 2, the control program PG1 is executed with the activation of the residual chlorine detection device 10, and the storage process (S11) thereof is executed. When the storage process (S11) is executed, the drainage valve 11V is closed and the water supply valve 12V is opened for a predetermined first water supply time, and then both valves 11V, 12V is closed. As a result, the storage unit 11 is filled with water.

As described above, as a configuration other than filling the storage unit 11 with water based on the water supply time, a pair of detection terminals are provided at the upper end of the storage unit 11, and the detection terminals are short-circuited with tap water. Depending on whether or not the reservoir 11 is full, it may be detected and the water supply valve 12V may be closed.

Next, the time measurement by the main timer is started (S12), and the stirrer 15 is started (S13). Then, the stirrer 15 is continuously operated until the main timer measures a predetermined first check time (for example, 22 hours from the start) (NO loop in S14). As a result, the treatment for removing free residual chlorine in the tap water stored in the storage unit 11 is completed, the storage unit 11 is filled with the treated tap water, and the pair of electrodes 16A and 16B are immersed in the treated tap water. It will be in the state of being done.

The tap water in the storage unit 11 may be left without the stirrer 15, but stirring with the stirrer 15 promotes the removal treatment of free residual chlorine. Further, the upper surface of the storage unit 11 may be closed, but if the upper surface is open as in the storage unit 11 of the present embodiment, the stored tap water comes into contact with air to remove free residual chlorine. Is promoted. Further, in order to promote the removal treatment of free residual chlorine, a substance that is easily combined with free residual chlorine and is difficult to be combined with other contents of tap water may be added to tap water. Examples of such substances include metals (iron, iron alloys, etc.) that easily corrode by combining with free residual chlorine. Further, the rotary blade 15A of the stirrer 15 may be configured with such a metal that is easily corroded. Here, since the solubility of the metal ion is much smaller than the solubility of the ion of the non-metal substance, it is presumed that the influence of the metal oxidation product on the voltage measurement is small. Further, when it is not necessary to promote the removal treatment of free residual chlorine, the cathodic protection may be performed on the rotary blade 15A, and the cathode protection may be canceled only when necessary.

The main timer measures the first check time (YES in S14), and when the stirrer 15 is stopped (S15), the main timer measures a predetermined second check time (for example, 15 minutes from the first check time). It is left until (NO loop of S16). As a result, the treated tap water in the storage unit 11 is hydrostatic.

When the main timer measures the second check time (YES in S16), the voltage between the pair of electrodes 16A and 16B immersed in the treated tap water is detected as the first voltage E1 (S17). This voltage detection is performed a plurality of times (for example, 10 times) at predetermined intervals (for example, 1 second), and the average thereof is stored as the first voltage E1.

After the detection of the first voltage E1, the water replacement process (S18) is performed. In the water replacement process (S18), the state in which the water supply valve 12V and the drainage valve 11V are both opened is maintained for the second water supply time, and then both valves 11V and 12V are closed. As a result, the tap water in the storage unit 11 is replaced with untreated tap water that has not been treated to remove free residual chlorine, and a pair of electrodes 16A and 16B are immersed in the untreated tap water. Become.

Here, the second water supply time is, for example, about 30 minutes, and is obtained experimentally. Specifically, for example, the tap water in the storage unit 11 is colored, the water supply valve 12V and the drainage valve 11V are opened together, and the time until the tap water in the storage unit 11 becomes colorless and transparent is the first. 2 It is experimentally calculated as the water supply time.

Further, as described above, the amount of water supplied through the water supply valve 12V is larger than the amount of drainage passing through the drainage valve 11V, so that the tap water is replaced in a state where the tap water overflows from the storage unit 11. As a result, the storage unit 11 is always maintained in a full water state, and the immersion state of the electrodes 16A and 16B is kept constant.

Next, wait until the main timer measures the third check time (for example, 15 minutes after the water replacement process (S18)) and wait for the untreated tap water in the storage unit 11 to become still water (NO in S19). The voltage between the pair of electrodes 16A and 16B immersed in untreated tap water is detected as the second voltage E2 (S20).

Next, the absolute value of the value obtained by subtracting the first voltage E1 from the second voltage E2 is calculated as the difference voltage ΔE (S21). Then, depending on whether or not the differential voltage ΔE is equal to or higher than the preset reference differential voltage L1, the free residual chlorine in tap water is equal to or higher than the reference concentration specified by law (for example, 0.1 [ppm] or higher). ) Is determined (S22), and if the concentration is not equal to or higher than the reference concentration, for example, an abnormality is notified to the detection main body at a remote location (S23). Then, the main timer is stopped and reset (S24), the process returns to step S12 described above, and the above operation is repeated.

In the present embodiment, the microcomputer of the control unit 20 executing step S21 corresponds to the "difference calculation unit" described in the claims. Further, in the present embodiment, it is detected whether or not the free residual chlorine is equal to or higher than the reference concentration, but the concentration of the free residual chlorine may be detected from the differential voltage ΔE and the preset data table. The value of the differential voltage ΔE itself may be output or stored as a detection result which is a substitute value for the concentration of free residual chlorine. Further, the first voltage E1 and the second voltage E2 may be transmitted to the detection main body unit, and the difference voltage ΔE may be obtained by the detection main body unit. In that case, the detection main body unit corresponds to the “difference calculation unit”. The "residual chlorine detection device" described in the claims is configured from the residual chlorine detection device 10 and the detection main body.

This concludes the description of the residual chlorine detection device 10 and the residual chlorine detection method of the present embodiment. Next, their action and effect will be described. As described above, in the residual chlorine detection device 10 and the residual chlorine detection method of the present embodiment, a pair of electrodes 16A and 16B are immersed in treated tap water that has been treated to remove free residual chlorine to obtain a first voltage E1. To detect. Then, the voltage component due to the inclusions other than free residual chlorine is subtracted from the second voltage E2 detected by immersing the pair of electrodes 16A and 16B in untreated tap water based on the first voltage E1, and the differential voltage ΔE is obtained. Since it is obtained, free residual chlorine can be detected with higher accuracy than before by using the differential voltage ΔE.

Here, since the pair of electrodes 16A and 16B are fixed to the storage unit 11, it is easy to make the detection conditions of the first voltage E1 and the second voltage E2 uniform. Further, the surface states of the pair of electrodes 16A and 16B differ depending on whether they are in contact with air or water, which can be a disturbing factor for voltage detection, but in the present embodiment, they are not treated with tap water. Since the storage unit 11 is always maintained in a substantially full state even when it is replaced with treated tap water, voltage detection with suppressed disturbance becomes possible. Further, the flow of tap water can also be a disturbance factor for voltage detection, but in the present embodiment, since the voltage is detected in a state where the tap water is hydrostatic, this also enables voltage detection with suppressed disturbance.

In the present embodiment, the difference voltage ΔE is obtained from the second voltage E2 and the first voltage E1 detected immediately before the second voltage E2, but from the second voltage E2 and the first voltage E1 detected immediately after that. The differential voltage ΔE may be obtained. In that case, a long processing time for removing free residual chlorine is required between the detection of the first voltage E1 and the second voltage E2, but as in the present embodiment, the second voltage E2 and its own are required. When the differential voltage ΔE is obtained from the first voltage E1 detected immediately before, both the first voltage E1 and the second voltage E2 can be detected in a short time, and the detection conditions can be easily made uniform. Become.

[Second Embodiment]
The residual chlorine detection device 10V of the present embodiment is shown in FIG. 4, and the structure of the storage portion 30 is mainly different from that of the first embodiment. That is, the residual chlorine detection device 10V of the present embodiment is provided with a water supply valve 12V and a drainage valve 11V at the upstream and downstream portions of the branch path 31 branched from the water supply pipe 13, and stores the intermediate portion between them. It is the part 30. Further, the electrodes 16A and 16B are fixed so as to penetrate the storage portion 30. The residual chlorine detection device 10V of the present embodiment is not provided with the stirrer 15 and the drain pan 14. Other configurations are the same as those in the first embodiment. The configuration of the present embodiment also exerts an action and effect in the same manner as the first embodiment.

[Third Embodiment]
The residual chlorine detection device 10W of the present embodiment is shown in FIG. 5, and is a modification of the second embodiment, in which the water supply pipe 13 is separated from the pair of electrodes 16A and 16B penetrating the storage portion 30. It is provided with a pair of electrodes 16C and 16D penetrating the above. Then, the first voltage E1 is detected by the electrodes 16A and 16B fixed to the storage unit 30, and the second voltage E2 is detected by the electrodes 16C and 16D fixed to the water supply pipe 13. Further, the correction coefficient is experimentally determined based on the difference when the electrodes 16A and 16B fixed to the storage unit 30 and the electrodes 16C and 16D fixed to the water supply pipe 13 are immersed in the same tap water and the voltage is detected. The control unit 20 calculates the difference voltage ΔE by subtracting the correction coefficient of the first voltage E1 from the second voltage E2. Other configurations are the same as those of the second embodiment, and the configurations of the present embodiment also have the same effects as those of the first and second embodiments.

[Other embodiments]
(1) In the residual chlorine detection device 10 of the first embodiment, after detecting the second voltage E2 in step S20, the main timer waits until the main timer measures 24 hours, then stops and resets (S24), and the above is performed. The configuration may return to step S12 so that the first voltage E1 and the second voltage E2 are detected at the same time every day. Further, a plurality of storage portions 11 and electrodes 16A and 16B may be provided so that the first voltage E1 and the second voltage E2 can be detected a plurality of times at predetermined intervals each day.

(2) In the second and third embodiments, as shown in FIGS. 4 and 5, the cross section of the portion of the branch path 31 that is the storage portion 30 is larger than the cross section of the other portion. However, the entire storage unit 30 may have a pipe structure having a uniform diameter, and the storage unit 30 may have the same pipe structure as both ends of the branch path 31.

10,10V, 10W Residual chlorine detector 11,30 Storage unit 11A Drainage port 11V Drainage valve 12 Water pipe 12A Water supply port 12V Water supply valve 13 Water supply pipe 15 Stirrer 16A-16D Electrode 17 Measuring unit 20 Control unit (difference calculation) Department, valve control unit)
E1 1st voltage E2 2nd voltage ΔE Difference voltage

Claims (11)

A residual chlorine detector that detects free residual chlorine in tap water.
A removal treatment unit that removes the free residual chlorine from tap water discharged from a water pipe,
A pair of electrodes with different ionization tendencies and
The first voltage generated between the electrodes when the pair of electrodes is immersed in the treated tap water that has been removed, and the pair of electrodes in the untreated tap water that has not been removed. A measuring unit that detects the second voltage generated between the electrodes while the water is immersed in the water,
A difference calculation unit for obtaining a differential voltage by subtracting a voltage component of tap water containing a substance other than the free residual chlorine from the second voltage based on the first voltage.
Residual chlorine detector equipped with. The removal processing unit has a storage unit in which tap water discharged from the water pipe is stored for a predetermined reference time or longer, and the removal treatment is performed by storing the tap water for the reference time or longer.
The residual chlorine detection device according to claim 1, wherein the first voltage and the second voltage are detected in a state where the pair of electrodes is fixed to the storage portion. The residual chlorine detection device according to claim 2, wherein the difference calculation unit obtains the difference voltage from the second voltage and the first voltage detected immediately before the detection of the second voltage. A drainage port that drains tap water from the reservoir and is opened and closed by a drainage valve,
A water supply port that supplies tap water to the storage unit and is opened and closed by a water supply valve,
The drain valve and the valve control unit for controlling the water supply valve are provided so that the storage unit is always maintained in a substantially full state including when the treated tap water is replaced with the untreated tap water. The residual chlorine detection device according to claim 2 or 3. The amount of water supplied from the water supply port when the water supply valve is fully open is larger than the amount of drainage from the drainage port when the drainage valve is fully open.
The residual chlorine detection device according to claim 4, wherein the valve control unit fully opens both the drainage valve and the water supply valve when the inside of the storage unit is replaced with the untreated tap water. .. The residual chlorine detection device according to claim 1, further comprising a stirrer for stirring tap water in the reservoir. The residual chlorine detection device according to claim 1, wherein the upper surface of the storage portion is open. It is a residual chlorine detection method that detects free residual chlorine in tap water.
A pair of electrodes having different ionization tendencies are immersed in the treated tap water which has been treated to remove the free residual chlorine from the tap water discharged from the water pipe, and the first voltage generated between the electrodes is detected and described above. The pair of electrodes is immersed in untreated tap water that has not been removed, and the second voltage generated between the electrodes is detected.
The voltage component due to the inclusions other than the free residual chlorine in tap water is subtracted from the second voltage based on the first voltage to obtain the differential voltage, and the differential voltage is used to detect the free residual chlorine. Chlorine detection method. The removal treatment is performed by storing the tap water discharged from the water pipe in the storage unit for a predetermined reference time or longer.
The method for detecting residual chlorine according to claim 8, wherein the pair of electrodes is fixed to the storage portion to detect the first voltage and the second voltage. The residual chlorine detection method according to claim 9, wherein the differential voltage is obtained from the second voltage and the first voltage detected immediately before the detection of the second voltage. The residual chlorine detection method according to claim 9 or 10, wherein the storage portion is always maintained in a substantially full state including when the treated tap water is replaced with the untreated tap water.

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