JP3730688B2 - Rust prevention method and equipment for water pipe system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water pipe system, in particular, a rust prevention method and apparatus for buildings and water pipes in buildings.
[0002]
[Prior art]
Water pipes such as buildings are rusted when 15 years have passed since construction, and they are contained in water and combined with impurities, and accumulate as so-called rust. If this is left unattended, the piping will corrode, and in a few years, a situation will occur in which replacement takes place at an enormous cost.
[0003]
In order to prevent the generation of red water due to rust in this water pipe, JP-A-64-75693, JP-B-5-25954, JP-B-5-25954, JP-A-5-10465, JP-A-5-10465, As disclosed in Japanese Patent Application Laid-Open No. 6-12464, etc., many methods have been proposed in which a metal serving as an anode is disposed in a water pipe and a corrosion prevention current is passed from the anode to a water pipe serving as a cathode to prevent rust.
[0004]
[Problems to be solved by the invention]
However, when such a red water generation prevention device is to be attached to an aging pipe, not only is the cost increased, but it is necessary to stop water supply for the attachment.
[0005]
The problem to be solved in the present invention is that it can be performed easily and with good reproducibility in applying a potential to tap water flowing in the water pipe and passing a weak current through the water to rust the water pipe. It is to provide means.
[0006]
[Means for Solving the Problems]
By supplying a weak current from the outside to the water in the water storage tank , the present invention charges the water for water supply in the water storage tank, and supplies the charged water to the water supply pipe from the water storage tank . In the rust prevention method of the water pipe system that lowers the surface potential of the water pipe and maintains the inert state where rust and corrosion do not occur in the water pipe , the charge amount to the water for water supply in the water storage tank is stored It is characterized in that the pH of the water flowing through the water supply pipe from the tank is measured and controlled according to the fluctuation of the measured pH.
[0007]
The electric potential charged in the water storage tank replenishes the tap water flowing through the pipe, keeps the pipe in a stable state, prevents ionization, and prevents the generation of rust. Further, by adding an electric current to this, the surface of the water pipe is usually at a potential of about -0.6 volts, and an inert state in which the water pipe does not rust or corrode is maintained. That is, when a weak current is supplied to water from the outside, the periphery of the pipe through which the current flows changes to weak alkalinity. The slightly acidic rust on the surface of the water pipe becomes slightly alkaline due to the weak current supplied from the anode, neutralizes with water and dissolves in water. However, when the current value is high, rust and corrosion progress on the contrary due to excessive inactive state.
[0008]
The present invention maintains such an appropriate value of the supply current by measuring the pH value of the water flowing in the pipe and appropriately controlling the potential applied to the water in accordance with the fluctuation of the measured pH. To do.
[0009]
The maintenance of the appropriate value of the supply current is not only applicable to the first invention of the present application, but can also be arbitrarily applied to the control of the applied potential when applying the potential to the anode installed in the conventional pipe.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In carrying out the present invention, as an electrode, in order to minimize electric corrosion, titanium is used for the substrate, and platinum-plated material is used, and 5-10 mm from the electrode surface is used. A platinum pH sensor is also arranged at an interval, and the amount of potential applied, that is, the current value is controlled by a transmission controller for supplying a potential to the pH value obtained therefrom.
[0011]
【Example】
FIG. 1 shows that between a 10-ton roof tank OT and a 20-ton underground tank UT installed on the roof of the building, the pipe inner diameter is 200 mm, the total length is about 500 m, and the normal water circulation rate is An example will be shown in which a device 1 for applying an electric charge to supply tap water from the roof tank OT is installed by applying to a water pipe system in which a 30 m ³ water pipe SP is disposed.
[0012]
2A, 2B, and 2C show a specific configuration of the charge applying device 1 shown in FIG. FIG. 4A shows the side plate 2 and the wiring 3 constituting the box of the charge applying device 1. FIG. 2B shows the structure of the side plate 2. The side plate 2 is made of a weather-resistant plastic. An opening 4 is formed in the side plate 2, and an anode 5 in which a titanium plate is covered with platinum is disposed facing the opening 4. FIG. 2C shows a stainless steel plate 9 having a cross section that forms the cathode 6 of the charge applying device 1, and is mounted in an insulated state at the center of the box. The anodes 5 on the inner surface of the side plate 2 shown in FIG. 2A were assembled facing inward, and a cathode 6 made of a stainless steel plate 9 was mounted in the center of the side plate 2 in an insulated state from the box side plate 2. The total area of one side of the anode 5, in 280 cm ^2, the effective area of the whole forms a 4200Cm ^2, the effective area of the cathode 6 is formed in 5700Cm ^2, spacing the anode 5 and the cathode 6, was 150 mm. A non-illustrated pH meter with a safety cover was fixed on the anode surface.
[0013]
FIG. 3 is a diagram showing a system configuration of the charge applying device 1. In the figure, each anode 5 of the charge application device 1 and a cathode 6 connected to a water supply pipe 7 and grounded are connected to a high frequency transmitter (controller) 8 of a control unit. The controller 8 is configured to adjust the energization amount to be constant with respect to fluctuations with respect to the set value of the pH meter.
[0014]
In this system, a 50-Hz 100 V AC power source was applied to the high-frequency transmitter 8 and charged from the charge applying device 1 installed in the rooftop tank OT storing water shown in FIG.
[0015]
FIG. 4 shows the change in the redox potential of water over time after installation, measured in a tank using tap water as raw water. As seen in the figure, the potential of water in the circulation tank dropped from 800 mV to 200 mV or less immediately after installation, and maintained a substantially constant value for about 100 hours. During this period, the inner surface of the water pipe at each position of the water pipe changed from red rust to black rust. After that, the energization amount was adjusted by the change from pH value 7.7.
[0016]
FIG. 5 shows the fluctuation of the pH value of the water in the circulation tank with the elapsed time after the operation of the charge applying device, and FIG. 6 shows the electricity of the water supply water in the circulation tank with the elapsed time after the installation. It shows the variation of conductivity. Furthermore, FIG. 7 shows the change in the amount of dissolved oxygen.
[0017]
As a result, there was no fluctuation in the electrical conductivity of the water supply water supply, tap water with a stable dissolved oxygen amount could be supplied, corrosion of the water pipe could be prevented, and furthermore, the corroded water pipe could be restored to a clean state. .
[0018]
【The invention's effect】
The following effects can be achieved by the present invention.
[0019]
(1) It can be easily installed in existing water pipe systems as well as newly installed, and it has excellent rust removal and rust prevention effects, and the life of old pipes can be extended.
[0020]
(2) Not only rust prevention, but also the alkalinity of supply water and oxygen enrichment are significant, contributing to water quality improvement.
[0021]
(3) The present invention is not limited to a closed system such as a building, but can be easily applied to a cooling water circulation device and a mold cooling device, and also improves rust prevention and cleaning effects by improving water quality.
[Brief description of the drawings]
FIG. 1 shows a water pipe system to which the present invention is applied.
FIG. 2 shows a configuration of a charge imparting device.
FIG. 3 shows a system configuration of the charge application device.
FIG. 4 shows a change in redox potential of tap water over time after the operation of the charge imparting device.
FIG. 5 also shows the change in pH value.
FIG. 6 also shows the change in electrical conductivity.
FIG. 7 also shows the change in the amount of dissolved oxygen.
[Explanation of symbols]
OT rooftop tank UT underground tank SP water pipe system 1 charge applicator 2 side plate 3 wiring 4 opening 5 anode 6 cathode 7 water supply pipe 8 high frequency transmitter (controller)
9 Stainless steel plate

Claims (2)

By supplying a weak current from the outside to the water in the water storage tank , the water for the water supply is charged in the water storage tank , and this charged water is supplied to the water supply pipe from the water storage tank , so that the surface of the water pipe In the water pipe system rust prevention method to reduce the potential of the water pipe and maintain the inert state where rust and corrosion do not occur in the water pipe,
The amount of electric charge to the water for water supply in the water storage tank is measured by measuring the pH of the water flowing through the water supply pipe from the water storage tank, and is controlled according to the fluctuation of the measured pH. Rust method. Each anode of the charge applying device installed in the water storage tank and the cathode grounded by connecting to the water supply pipe to the water storage tank are connected to the high frequency transmitter, and a pH meter is provided in the water pipe from the water storage tank,
The high-frequency transmitter is a water pipe rust prevention device that adjusts the amount of current to keep constant with respect to fluctuations in the set value of the pH meter .

Images