KR20070044738A - Protection monitoring system - Google Patents

Abstract

It relates to a method of detecting the way of pipes and the degree and point of damage to the pipes by overeating or spreading by measuring the anticorrosive potential and anticorrosive current of pipes embedded in soil using galvanic current. A system for detecting the corrosion status of a finished pipe, comprising a sensor for detecting corrosion and a zero resistance ammeter for measuring the galvanic current induced by the sensor, wherein the sensor for detecting corrosion is formed of anode and purity made of the same material as the pipe being measured. The negative electrode is made of 99.99% or more of copper.

By measuring the galvanic current induced in the corrosion detection sensor as described above, the degree of corrosion of the pipe is quantitatively determined by using the correlation with the corrosion state (anticorrosive potential and anticorrosive current) of the pipe in which the cathode method is in progress. By presenting it, the anticorrosive condition of the pipe can be easily detected, and the problem of damage to the pipe due to overheating or electroplating can be prevented in advance.

Method, Cathode Method, Corrosion Current, Corrosion Prevention, Anticorrosive Potential, Anticorrosive Current, Galvanic Current, Sensor, Piping

Description

Protection monitoring system

1 is a schematic diagram of an iron- copper anti-corrosion system according to the present invention,

2 is a view showing the chemical composition of the positive electrode material,

3 is a configuration diagram of a galvanic sensor for corrosion detection shown in FIG.

4 is a conceptual diagram showing the configuration of the artificial leachate immersion cell for applying the system according to the present invention,

5 is a view showing the artificial leachate immersion cell according to the configuration shown in FIG.

6 is a view showing the configuration of a seal pipe cell;

7 is a view showing a relationship between a pipe applied current and a sensor current;

8 is a view showing a relationship between an anticorrosive current and a sensor current;

9 is a diagram showing the relationship between the anticorrosive potential and the sensor current;

10 is a view showing the electrical and anticorrosive state of the pipe through the sensor current,

11 is a view showing a potential change of the pipe and the sensor electrode according to the application of the anticorrosive current,

12 is a view showing a change in pipe corrosion potential and sensor current with or without anticorrosive current applied;

13 is a view showing a change over time of the anticorrosive potential and sensor current of the pipe in the actual pipe cell;

14 is a diagram showing a relationship between sensor current and anticorrosive potential in a real pipe cell;

Explanation of symbols on the main parts of the drawings

10: positive electrode 20: ammeter

30: reference electrode 40: buried pipe

50: voltmeter 60: galvanic sensor

The present invention relates to an anticorrosive detection system of underground pipes, and more specifically, by measuring the anticorrosive potential and anticorrosive current of pipes embedded in soil using galvanic current, by the anticorrosive state of the pipes and by overeating or electroplating. It relates to a sensing system that monitors the extent and point of damage to the piping.

In general, the anticorrosive performance evaluation of piping is qualitatively judged by the change of anticorrosive potential by measuring the potential of the ground. However, this method requires a technique for monitoring the quantitative cathodic state because it is difficult to accurately measure the potential potential because IR drop is included in the measurement potential due to soil resistivity or coating resistance. The importance of systems for assessing the effects of interference, such as the vault current, is also emerging.

An example of a system for measuring anticorrosive potential for anticorrosive performance of piping is disclosed in Korean Laid-Open Patent Publication No. 2004-88683, Japanese Laid-Open Patent Publication No. 5-107217, and the like.

That is, Japanese Patent Laid-Open No. 5-107217 relates to a piping device having a function for measuring a corrosion tendency inside a pipe in a drainage system of a building, such as a building, and the like, to prevent corrosion of the pipe without causing a decrease in the reference electrode. A piping device that can be easily measured is disclosed.

In addition, Korean Patent Laid-Open Publication No. 2004-88683 discloses a cathode for corrosion detection apparatus of a pipe, in which the anode is formed in the same manner as the metal to be measured, and the cathode is a galvanic-based metal that is heterogeneous with the metal of the anode generating a galvanic current. It is disclosed that the galvanic metal has a potential difference of 200 to 900 mV, a pipe is embedded in the soil, and a specific resistance of the soil is 5000 Ωcm to 10000 Ωcm.

However, in the technique disclosed in the above publication, the potential and the reference potential of the object to be measured were measured. Therefore, when the voltage drop (IR-drop) due to soil resistivity or coating resistance is included in the measurement potential, there was a problem in that the exact anticorrosive potential cannot be measured.

Therefore, an object of the present invention is to solve the problems described above, and predict the anticorrosive potential and anticorrosive current of the pipe embedded in the soil using galvanic current, and furthermore, whether or not damage to the pipe by over-eating or electroplating It is to provide a detection system that can detect quantitatively and prevent pipe damage.

That is, the sensor anode of the present invention is formed of the same metal as the embedded pipe, and the cathode is made of copper which is easy to generate a galvanic current. As shown in FIG. 1, by measuring the galvanic current induced by the galvanic pair formation of the anode and cathode materials with a zero resistance ammeter (ZRA), the cathode method is being applied through the measured galvanic current amount. Indirectly detect the anticorrosive potential of the pipe.

In order to achieve the above object, the anti-corrosive detection system according to the present invention is a system for detecting the anticorrosive state of a pipe embedded in soil, and includes a sensor for corrosion detection and a zero resistance ammeter for measuring galvanic current induced in the sensor. The corrosion detecting sensor is characterized by consisting of a cathode formed of the same material as the pipe to be measured and a cathode made of copper having a purity of 99.99% or more.

In the anticorrosive detection system according to the present invention, the anticorrosive state of the pipe is quantitatively detected.

In the anticorrosive detection system according to the present invention, the galvanic current induced in the sensor and the anticorrosive potential of the pipe are linearly correlated.

In addition, in the anti-corrosion system according to the present invention, the anticorrosive state of the pipe is indirectly measured through a linear correlation, and the galvanic current is sensed through the sign of the galvanic current.

The above and other objects and novel features of the present invention will become more apparent from the description of the specification and the accompanying drawings.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated according to drawing.

1 is a schematic diagram of a manner sensing system according to the present invention.

As shown in FIG. 1, an anti-corrosion system according to the present invention includes an anode rod 10 serving as an anode embedded in soil, an ammeter 20 connected in series, and a reference electrode 30 between a buried pipe 40. The voltmeter 50, the galvanic sensor 60, and the zero resistance ammeter (ZRA) 70 which measure the electric current induced by the sensor 60 are connected.

That is, the sensor anode of the present invention is formed of the same metal as the embedded pipe, and the cathode is made of copper which is easy to generate a galvanic current. As shown in FIG. 1, by measuring the galvanic current induced by the galvanic pair formation of the anode and cathode materials with a zero resistance ammeter (ZRA), the cathode method is being applied through the measured galvanic current amount. Indirectly detect the anticorrosive potential of the pipe.

In the present invention, the material used as the anode of the sensor 60 is a water coated coating steel pipe (KS D3565), and the material used as the sensor cathode is copper. The composition of the coated steel pipe is shown in FIG. 2, and copper having a purity of 99.99% or more was used.

Next, a specific configuration of the galvanic sensor 70 for detecting corrosion shown in FIG. 1 will be described with reference to FIG. 3.

Using a given material, the anode is a coating steel pipe for water supply, and the corrosion sensor 70 for the cathode is manufactured as shown in FIG. In FIG. 3 (a), both the anode 61 and the cathode 62 were manufactured in the form of a rod having a diameter of 12 mm, and uniformly polished to # 600 with SiC abrasive paper prior to the experiment, and then washed and dried with ethanol and distilled water. .

In Fig. 3B, reference numeral 63 denotes a sensor body portion incorporating the positive electrode 61 and the negative electrode 62, and the positive electrode 61 and the negative electrode 62 are each a zero resistance ammeter ( 50 is a cable for connecting to the main body, 65 is a cover part covering the main body 62, 66 is the main body 63, the positive electrode 61, the negative electrode 62, the lead-out part of the cable 64, and It is a sealing part for sealing the coupling part of the cover part 65.

That is, when the galvanic sensor 60 according to the present invention is inserted into the soil containing moisture, each component part connected to the main body 63 is prevented from entering the main body 63. It is sealed by a seal 66 made of known waterproofing material.

Next, to clarify the relationship between the sensor current of the sensor 60 according to the present invention in the soil environment and the manner of the piping and the interference state, the immersion cell 70 was configured as shown in FIG. 4 in the artificial leachate environment. As shown in FIG. 4, the cell 70 includes a pipe (WE), a carbon rod (CE), and a saturated red electrode (RE) in the center of the cell 70 to simulate the manner and interference state of the water supply pipe. Located in In addition, to measure the galvanic current of the sensor 60, sensors 60 and 60 'made of copper-steel (Cu-CS) are disposed on both sides of the cell 70, and one sensor is a pipe specimen (WE). The other sensor (60 ') is connected to the steel pipe and the pipe specimen (WE) of the sensor to complete the immersion cell 70, as shown in FIG.

The measurement method simulates a situation in which an electric current occurs due to interference by applying an anode current to a pipe specimen, and simulates a situation in which the pipe 40 is a method when a cathode current is applied. At this time, the galvanic current was measured in each sensor to examine the effects of interference and method.

In order to measure galvanic current, a wide range of current and voltage control can be controlled by manual and computer, and Potentionstat (80) is applied to conveniently analyze data processing results.

 In order to change the size of the pipe specimen and the distance to the sensor 60, the seal pipe cell as shown in FIG. 6 is configured to detect the anticorrosion state of the pipe 40 under conditions similar to those in which the actual pipe 40 is embedded. Monitoring). The method of the pipe 40 was an external power supply method, and the correlation between the method potential of the pipe 40 and the current measured by the sensor 60 according to the method of applying the method current was compared.

In Fig. 6, reference numeral 41 denotes a coating member for covering the pipe 40, and reference numeral 42 denotes a power supply for supplying power to the pipe 40 and the positive electrode 10.

Next, the experimental results for identifying the correlation with the current of the sensor 60 according to the cathode method and the interference in the artificial leachate cell 70 according to the present invention will be described with reference to FIG.

When the positive or negative current is applied to the pipe in the state in which the positive electrode of the pipe 40 and the sensor 60 are not connected to FIG. 7 (a), the potential of the pipe 40 and the sensor current are shown. Before the current is applied to the pipe 40, the sensor current is measured with a positive sign, whereas when the cathode current is applied to the pipe 40, the current of the sensor changes to a negative value. . This means that the current flow of the sensor 60 initially flows from the positive electrode (steel pipe) to the negative electrode (copper), and when the current is applied, the direction of the current changes from the negative electrode to the positive electrode. In addition, it can be seen that the current of the sensor 60 also increases in the negative direction in proportion to the magnitude of the cathode current applied to the pipe 40. On the contrary, when an anode current is applied to the pipe 40, the sensor current also changes in the positive direction. That is, when the pipe 40 is a cathode type, the current of the sensor 60 has a negative sign and is proportional to the magnitude of the anticorrosive current, and when the pipe 40 is in an electrical state due to interference, the sensor It can be seen that the current of 60 changes with the sign of (+) in proportion to the magnitude of the vagus current.

In addition, even when the anode of the pipe 40 and the sensor 60 are connected as shown in FIG. 7B, the magnitude of the cathode or anode current applied to the pipe 40 and the sensor current are proportional to each other. The correlation between the current and the applied current code is not well established, which makes it difficult to distinguish between the state of the pipe 40 and the system.

Next, the correlation between the galvanic current and the anticorrosion potential of the pipe according to the measurement result according to FIG. 7 will be described with reference to FIGS. 8 and 9.

8 and 9 show the relationship between the anticorrosive current, anticorrosive potential, and sensor current based on the above measurement results. It can be seen that the following linear relationship is established between the anticorrosive current and the anticorrosive potential and the sensor current both when the pipe 40 and the sensor 60 are not connected.

When pipe and sensor are not connected

Sensor Current (uA / cm2) = (17.2 × Method Current (mA)) + 1.6

Sensor current (uA / cm2) = (285.1 × corrosion potential (VSCE)) + 267.2

When pipe and sensor are connected

Sensor Current (uA / cm2) = (10.3 × Method Current (mA))-76.3

Sensor current (uA / cm2) = (163.7 × anticorrosive potential (VSCE)) + 77.4

However, when the pipe 40 and the sensor 60 are not connected, the sign of the current applied to the pipe 40 and the sign of the sensor current are the same, so that it is easier to evaluate whether the wiring and the method through the measurement of the sensor current. Was supposed to.

Through the above results, it is possible to determine whether the pipe 40 is connected to the pipe 40 by measuring the sensor current, and the magnitude of the current applied to the pipe can be confirmed by monitoring the sensor current.

Next, the state for the detection of the electrical and system conditions of the pipe 40 through the sensor current will be described with reference to FIG.

As shown in FIG. 10, sensors 60 and 60 ′ were mounted on both sides of the pipe 40, and the cables of the respective sensors were connected to the zero resistance ammeter 70. That is, the sensor 60 is mounted in an area where corrosion occurs due to the vagus current, and the sensor 60 'is mounted in an area in which the anticorrosive current flows.

It was measured that the sign of the electric current of the sensors 60 and 60 'changes with the structure shown in FIG. Changing the sign of the sensor current means that the electrochemical characteristics of the positive and negative electrodes of the sensor change. In other words, the steel pipe, which is a component of the sensor, is more active than copper, and thus acts as an anode. In the state of anticorrosive current, the polarity of the steel pipe and copper is changed, and copper acts as an anode. Therefore, the effect of anticorrosive current on the change of electrochemical characteristics of sensor electrode was evaluated.

FIG. 11 shows the potential change of the anticorrosive potential of the pipe 40 and the electrode of the sensor when the anticorrosive current of -5 mA is applied to the pipe. At this time, copper and steel, which are sensor electrodes, independently measured the change in potential of the sensor electrode according to the method of the pipe 40 in the state of not being connected to each other. Before the anticorrosive current is applied, the corrosion potential of copper is the highest, and the corrosion potential of the steel of the pipe 40 and the sensor 60 is similar. However, when the anticorrosive current is applied to the pipe 40, not only the pipe but also the steel pipe and the copper, which are the sensor electrodes, are used. In this case, the anticorrosive potential of copper is lower than that of the steel pipe. That is, when anticorrosive current is applied to the pipe 40, copper having a lower anticorrosive potential acts as an anode, while a steel pipe having a high anticorrosive potential acts as a cathode, and thus the sign of the sensor current measured is negative. Will change.

12 shows the change in the potential and the sensor current of the pipe 40 when the anticorrosive current of −10 mA is applied to the pipe 40 for 10 hours and then the application of the anticorrosive current is stopped and maintained for 10 hours. When the anticorrosive current is applied, the polarity of the steel pipe and copper, which are the sensor electrodes, is changed, and the sensor current of (-) is measured. When the anticorrosive current is stopped, the steel pipe becomes the anode again and the positive sensor current is measured. .

Next, the correlation of the sensor current according to the cathode method and the interference in the actual piping cell according to the present invention will be described. Through the above research results, it was confirmed that the galvanic sensor 60 buried around the pipe 40 can monitor the interference and cathode type of the pipe. Therefore, in this study, we evaluated the characteristics of the sensor's anticorrosive state in the actual pipe cell.

Figure 13 shows the changes in the corrosion potential and sensor current of the pipe when the anti-corrosion current of -1.6 mA and -0.8 mA is applied to the pipe. In the real pipe cell, the corrosion behavior of the pipe and the change of sensor current were consistent with time. That is, the anticorrosive potential of the pipe can be predicted by measuring the current induced in the sensor, which shows a linear relationship as shown in FIG. 14.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

As described above, according to the anti-corrosion system according to the present invention, the anticorrosive potential of the pipe in which the negative electrode system is in progress can be predicted through the galvanic current induced by the sensor, and the influence of the over-provisioning and the electroplating also indicates the galvanic current. And quantitatively detectable through size.

In addition, according to the present invention, the anticorrosive state of the pipe is presented as a quantitative value through a linear correlation between the galvanic current induced between the iron-copper sensor and the anticorrosive potential of the pipe compared to conventional devices. Through this, effective maintenance and management can be achieved, and the effect of contributing to the effective management and reliability of infrastructure in social and economic aspects is also obtained.

Claims (4)

A system for detecting the condition of the pipes buried in the soil, Corrosion detection sensor It includes a zero resistance ammeter for measuring the galvanic current induced in the sensor, The corrosion detection sensor is an anti-corrosion detection system, characterized in that consisting of a cathode formed of the same material as the pipe to be measured and the cathode made of copper with a purity of 99.99% or more. The method of claim 1, Method of detecting the system characterized in that the detection of the manner of the pipe is quantitatively detected. The method of claim 2, Galvanic current induced in the sensor and the anticorrosive potential of the pipe has a linear correlation. The method of claim 3, wherein And a method of indirectly measuring the manner of the pipe through the linear correlation, and detecting the electrical distribution of the pipe due to the vagus current through the sign of the galvanic current.

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