JP2002153878A - Water quality maintenance equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the free residual chlorine concentration of the tap water stored in water storage tanks (elevated water tanks) of buildings and condominiums from lowering. SOLUTION: The water quality maintenance equipment 4 having an electrolytic cell 5 for converting the chlorine ions included in the tap water by electrolyzing the tap water to chlorine is installed in juxtaposition with the water storage tank 1. The water in the water storage tank 1 is circulated through the electrolytic cell 5 by a circulating pump 6, by which the free residual chlorine concentration of the tap water stagnating in water storage tank 1 is maintained at a specified range. At this time, the water temperature is captured by a water temperature sensor 33 and the operating time per time is calculated from the temperature of the raw water and the previously measured chlorine ion concentration and the electrolytic cell 5 and the circulating pump are operated for the calculated time at the prescribed time plural times a day.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water quality maintaining device for maintaining the concentration of free residual chlorine in tap water stored in a water tank of a building or an apartment.

[0002]

2. Description of the Related Art In general, in buildings and condominiums, tap water received by a water receiving tank on the ground is used as a water storage tank on a roof (an elevated water tank).
The water is supplied to each faucet from this water tank. On the other hand, the water supply law stipulates that the concentration of free residual chlorine at the tap of a water supply should be 0.1 mg / l or more, but the concentration of free residual chlorine of 0.3 to 0.5 mg / l is necessary to maintain safe water quality. It is supposed to be.

[0003]

However, the elevated water tank is an open tank, and when the residence time of tap water is prolonged, chlorine is released, and germs easily propagate. In particular, when there is a lot of ultraviolet rays at high temperatures like in summer or when the number of residents decreases due to returning home, the amount of water used drops extremely and the residence time of water becomes longer, the concentration of free residual chlorine drops significantly. . This decrease in the concentration of free residual chlorine is an important problem that directly leads to deterioration of water quality. Therefore, an object of the present invention is to compensate for a decrease in the concentration of free residual chlorine in tap water in a water storage tank and always maintain an effective concentration of free residual chlorine in a certain range.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention aims to maintain the water quality of a water storage tank by generating chlorine using chlorine ions contained in tap water. That is, the water quality maintaining device of the present invention comprises an electrolytic cell that electrolyzes tap water containing chlorine ions to generate chlorine, a circulation pump and a circulation pipe that circulate the tap water stored in the water storage tank through the electrolytic cell. And a control means for operating the electrolytic cell and the circulating pump to perform electrolysis while circulating the tap water in the water tank, so that the concentration of free residual chlorine in the tap water stored in the water tank is within a certain range. To maintain.

[0005] The control means of the water quality maintaining device adjusts the operation time in accordance with the chlorine ion concentration of tap water in the water storage tank. Further, the water quality maintaining device includes a water temperature sensor that detects a temperature of tap water in the water storage tank or the circulation pipe, and the control unit adjusts an operation time according to the water temperature detected by the water temperature sensor. (Claim 2). Furthermore, the control means of the water quality maintaining device adjusts the operation time according to the capacity of the water storage tank (claim 3). Furthermore, the water quality maintaining device includes a water temperature sensor for detecting a temperature of tap water in the water storage tank or the circulation pipe, and the control unit detects the chlorine ion concentration of the tap water in the water storage tank and detects the water temperature sensor using the water temperature sensor. The operation time is adjusted according to the water temperature and the capacity of the water storage tank (claim 4).

[0006]

FIG. 1 is a system configuration diagram of a water quality maintenance device showing an embodiment of the present invention, and FIG. 2 is a control block diagram of the device of FIG. 3A and 3B show the electrolytic cell in FIG. 1, wherein FIG. 3A is a partially cutaway plan view, and FIG. 3B is a sectional view taken along the line BB. First, in FIG. 1, reference numeral 1 denotes a water storage tank installed on the roof of a building or the like, which stores tap water pushed up by a pump (not shown) from a water receiving tank (not shown) installed on the ground. Tap water in the water storage tank 1 is supplied to each faucet from the water outlet 2 and when the water level falls to the lower limit level, the pump is started by a signal from a water level sensor (not shown), and the tap water in the water receiving tank is supplied to the water inlet 3.
It is replenished from to the maximum level. The tap water in the water storage tank 1 is sterilized with chlorine, but as described above, chlorine gradually escapes as the residence time elapses, and germs easily propagate.

On the other hand, a water quality maintenance device 4 is installed alongside the water storage tank 1, and tap water in the water storage tank 1 is circulated through the water quality maintenance device 4 to maintain the free residual chlorine concentration. The water quality maintaining device 4 includes an electrolytic cell 5 that electrolyzes tap water to generate chlorine from chlorine ions in a box-shaped main body.
And a circulating pump 6 and a circulating pipe 7 for circulating tap water stored in the water tank 1 through the electrolytic tank 5, and a control unit 8 for activating the electrolytic tank 1 and the circulating pump 6 at a preset time.
And is installed. A circulation pump 6 is provided in the circulation line 7.
Leak detection valve 9 that shuts off the pipe line when water leaks before
A water temperature sensor 33 for detecting the temperature of tap water is inserted in front of the electrolytic cell 5. Further, inside the main body, an antifreeze heater 10, a circulation fan 11 for circulating air inside the machine through the antifreeze heater 10, an air temperature sensor 12 for detecting the air temperature inside the machine, an exhaust fan 13 for discharging air inside the machine, A water leak detector 14 and the like for detecting water leak from a water pool on the floor inside the machine are installed. The same four electrolyzers 5 are installed to adjust the electrolysis capacity.
They are connected in series two by two, and furthermore, they are connected in parallel.

The structure of the electrolytic cell 5 will be described with reference to FIG.
3A shows a state in which the case 15 and the anode 19 of the upper electrode 7 in FIG. 3B are removed. In FIG. 3, the electrolytic cell 5 includes a case 15 and a cover 1.
6, two sets of electrodes 17 are arranged on both sides of a partition plate 18 in a container made of a molded resin divided into six parts. Each of the electrodes 17 is composed of two positive and negative electrode plates 19 and 20. These electrode plates 19 and 20 are arranged to face each other with a frame-shaped spacer 21 made of a thin resin film therebetween. Each terminal 22 is joined. At the left end of FIG. 3 of the electrolytic cell container, one water inlet 23 having one end closed so as to straddle two sets of electrodes 17 is provided. Further, at the right end, two water outlet channels 24 for each electrode are provided, and one end thereof is closed on the side opposite to the water inlet channel 23. As shown in FIG. 3A, a pipe joint 25 is attached to an open end of the water inlet channel 23, and a pipe joint 26 spanning the two water outlet channels is attached to an open end of the water outlet channel 24.

In such an electrolytic cell 5, when a DC voltage having the illustrated polarity is applied to each of the electrode plates 19 and 20 of the two sets of electrodes 17 via the terminals 22 and tap water is supplied from the water inlet channel 23, Tap water undergoes electrolysis while passing through the electrode, and chlorine ions in the tap water are converted to chlorine by a reaction of 2Cl ⁻ → Cl ₂ + 2e ^{− at} the anode. The tap water containing chlorine is collected in the water discharge passage 24 for each electrode as shown by arrows in the drawings, further mixed by the pipe joint 26, and led to a hose (not shown) constituting a circulation pipeline.

The control operation of the control section 8 will be described next. First, the decrease in the chlorine concentration of the stored water in the water storage tank 1 is affected by the water temperature. The decrease is small when the water temperature is low, and is large when the water temperature is high. Therefore, the water temperature is divided into several stages, and a target increase value of the free residual chlorine concentration due to the electrolysis of the stored water is determined for each stage. Table 1 shows one example.

[0011]

[Table 1]

Next, the amount of chlorine generated per unit time (mg / min) by electrolysis of tap water is substantially proportional to the concentration of chlorine ions (mg / l) in raw water. Therefore, although the amount of generated chlorine varies depending on the quality of the raw water, according to experiments performed by the inventors, it has been found that this proportional relationship changes at a water temperature of about 10 ° C., and the chlorine generation decreases in a higher temperature range. Chloride ion concentration B
As an example of the approximate expression of the amount L of chlorine generated by K, K ₀ , K ₁ ,
Assuming that K ₂ is a proportional constant, the following is obtained. 0 <B <10 Chlorine generation amount L (mg / min) = K ₁ × B 10 ≦ B Chlorine generation amount L (mg / min) = K ₂ × B + K ₀

The amount of chlorine generated also depends on the temperature of the raw water. According to experiments performed by the inventors, it has been found that the amount of chlorine generated is small even when the water temperature is low or high, and is large in the intermediate region. Therefore, the chlorine generation amount L needs to be corrected by the water temperature (° C.), and the correction is approximated by the following equation using M ₁ and M ₂ as proportional constants.

L is the amount of chlorine generated per electrolytic cell. In the water quality maintaining apparatus of the illustrated embodiment including four electrolytic cells 5, the amount of chlorine generated L depends on the number of electrolytic cells 5 to be operated.
Is corrected as follows. Electrolyzer 2 Chlorine generation L = L × 2 Electrolyzer 4 Chlorine generation L = L × 4

From the above, when the capacity of the water storage tank 1 is A (t) and the daily operation time T (minutes) is calculated, D <10 1 day operation time T (minutes) = A × 1000 × 0.05 ÷ L = 50 × A ÷ L 10 ≦ D <20 One-day operation time T (minutes) = A × 1000 × 0.1 ÷ L = 100 × A ÷ L 20 ≦ D <30 One-day operation time T (minutes) = A × 1000 × 0.2 ÷ L = 200 × A ÷ L 30 ≦ D One-day operation time T (minutes) = A × 1000 × 0.3 ÷ L = 300 × A ÷ L. Therefore, assuming that the number of operations per day is C (times / day), the operation time T1 (minutes / times) per operation is T / C. Table 2 shows an example of operation time in the illustrated embodiment.

[0016]

[Table 2]

In FIG. 2, the water tank capacity A, the chloride ion concentration B, the number of operations C, the operation time, the number of electrolytic cells and the like are previously set and input into the control unit 8 from the keyboard 27. Therefore, the control unit 8 takes in the water temperature data from the water temperature sensor 33 and calculates the operation time T1 per operation. Then, at a predetermined operation time, for example, at 0, 4, 8, 12, 12, 16 and 20 o'clock if the number of operations per day is 6, the electrolytic cell 5 is supplied from the power supply 28 via the polarity switching relay 29. , A circulating pump 6 is activated, and the tap water in the water storage tank 1 is circulated through the electrolytic tank 5. As a result, the chlorine ions in the tap water passing through the electrolytic tank 5 are converted into chlorine, and the tap water which has become rich in chlorine is returned to the water tank 1, and the chlorine in the tap water in the water tank 1 lost due to the stagnation. Is replenished. When the predetermined time has elapsed, the operations of the electrolytic cell 5 and the circulation pump 6 are stopped. By this repetition, the free residual chlorine concentration of the tap water in the water storage tank 1 is maintained in an appropriate range, for example, around 0.5 mg / l.

The control unit 8 also monitors the air temperature inside the machine by the air temperature sensor 12, and when the air temperature drops to a certain value, energizes the antifreeze heater 10 and starts the circulation fan 11 to circulate the warm air. While the various parts in the machine are prevented from freezing, when the air temperature rises to a certain value, the exhaust fan 13 is started to exhaust the machine air and to introduce the outside air to cool the inside of the machine. Further, when a water leak is detected by the water leak detector 14, the water leak detection valve 9 is closed to stop the water from leaking into the machine.

[0019]

As described above, according to the present invention, free residual chlorine in the storage water in the water storage tank is automatically maintained at a concentration required for the disinfection effect, and the generation of germs is suppressed to provide water that is always safe. Can be provided. In addition, maintenance and management are easy because chlorine ions contained in tap water are used and no chemical is used.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a water quality maintenance device showing an embodiment of the present invention.

FIG. 2 is a control block diagram of the apparatus of FIG.

3 shows the electrolytic cell in FIG. 1, (A) is a plan view,
(B) is a cross-sectional view along the line BB.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water storage tank 4 Water quality maintenance device 5 Electrolysis tank 6 Circulation pump 7 Circulation pipe 17 Electrode 18 Partition plate 19 Electrode plate 20 Electrode plate 21 Spacer 22 Terminal 23 Water inlet 24 Water outlet 28 Power supply 33 Water temperature sensor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 1/50 550 C02F 1/50 550H 560 560F 1/76 1/76 A (72) Inventor Takeshi Kasai Kanagawa 1-1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-ku, Japan F-term in Fuji Electric Co., Ltd. (reference) 4D050 AA04 AB06 BB04 BD06 CA10 4D061 DA03 DB10 EA02 EB02 EB04 EB33 EB37 EB39 GA05 GA09 GA30 GC15

Claims (4)

[Claims] 1. An electrolytic cell for electrolyzing tap water containing chlorine ions to generate chlorine, a circulation pump and a circulation line for circulating tap water stored in a water storage tank through said electrolytic tank, and said electrolytic tank. And a control means for operating a circulation pump and performing electrolysis while circulating the tap water in the water storage tank.The control means adjusts the operation time according to the chlorine ion concentration of the tap water in the water storage tank. A water quality maintaining device for maintaining the concentration of free residual chlorine in tap water stored in the water storage tank within a certain range. 2. An electrolytic cell for electrolyzing tap water containing chlorine ions to generate chlorine, a circulation pump and a circulation line for circulating tap water stored in the water tank through the electrolytic tank, and the water tank. Or, a water temperature sensor that detects the temperature of tap water in the circulation pipeline, and operates the electrolytic cell and the circulation pump,
Control means for performing electrolysis while circulating the tap water in the water tank, the control means adjusts the operation time according to the water temperature detected by the water temperature sensor, the tap water stored in the water tank A water quality maintenance device characterized by maintaining a free residual chlorine concentration within a certain range. 3. An electrolytic cell for electrolyzing tap water containing chlorine ions to generate chlorine, a circulation pump and a circulation line for circulating tap water stored in a water storage tank through said electrolytic tank, and said electrolytic cell. And a control means for operating a circulation pump and performing electrolysis while circulating tap water in the water storage tank.The control means adjusts an operation time according to the capacity of the water storage tank, and stores the water in the water storage tank. A water quality maintaining device for maintaining the concentration of free residual chlorine in tap water within a certain range. 4. An electrolytic cell for generating chlorine by electrolyzing tap water containing chlorine ions, a circulation pump and a circulation line for circulating tap water stored in a water tank through said electrolytic tank, and said water tank. Or, a water temperature sensor that detects the temperature of tap water in the circulation pipeline, and operates the electrolytic cell and the circulation pump,
Control means for performing electrolysis while circulating tap water in the water tank, the control means controlling the chlorine ion concentration of the tap water in the water tank, the water temperature detected by the water temperature sensor, and the capacity of the water tank. A water quality maintenance device, wherein an operation time is adjusted in accordance therewith to maintain the concentration of free residual chlorine in tap water stored in the water storage tank within a certain range.