Sacrificial anode structure, and sacrificial anode consumption state determination system and method

Abstract

To make it possible to more accurately determine a consumption state of a sacrificial anode.SOLUTION: There is provided a sacrificial anode structure, including: a sacrificial anode 11; a waterproof container 14 which is a hollow container in which at least the part of a body is embedded in the inside of the sacrificial anode 11 and which is constituted so that water does not enter from other places than a through-hole 21 opened at a predetermined position of the body; and a water entry sensor 15 arranged inside the waterproof container 14; wherein the through-hole 21 is provided at a position where the through-hole is embedded in the sacrificial anode 11 and where the through-hole starts to be exposed from a dissolution surface of the sacrificial anode 11 when a consumption amount of the sacrificial anode 11 reaches a desired amount. Thus, when the consumption amount of the sacrificial anode 11 reaches a desired amount, water enters the inside of the waterproof container 14 from the through-hole 21, and by detecting the water entry by the water entry sensor 15, it is possible to grasp that the consumption amount of the sacrificial anode 11 reaches the desired amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sacrificial anode structure, and a system and method for determining the wear state of a sacrificial anode, and in particular to a sacrificial anode structure provided to prevent corrosion of steel materials to be protected against corrosion that are installed underwater or underground in port steel structures or river structures such as steel pipe piles or steel sheet piles, and a system and method for determining the wear state of a sacrificial anode. [Background technology]

[0002] Conventionally, cathodic protection using sacrificial anodes (also called galvanic anodes) whose main components are Al, Zn, and Mg, each of which has a higher ionization tendency than the steel material to be protected from corrosion, has been widely used as a method for preventing corrosion of steel materials to be protected from corrosion, such as steel pipe piles or steel sheet piles that form the foundations of port facilities such as piers or revetments, in seawater, river water, or soil. Among these sacrificial anodes, there is a type that is supported by a metal core that penetrates the inside of the sacrificial anode and is attached to the steel material to be protected from corrosion (see, for example, Patent Documents 1 and 2).

[0003] When implementing cathodic protection using sacrificial anodes, it is necessary to monitor whether the sacrificial anodes are generating the designed protective current, periodically monitor the wear state of the sacrificial anodes, and understand the potential of the steel material being protected and the lifespan of the sacrificial anodes.Theoretically, the wear of a sacrificial anode is proportional to the product of the generated current and time (amount of electricity) according to Faraday's law, so by measuring the current generated by the sacrificial anode over time, it is possible to estimate the wear of the sacrificial anodes.

[0004] Known prior art for predicting the lifespan of a sacrificial anode is, for example, the technology described in Patent Document 3. The lifespan prediction device described in Patent Document 3 includes an Mg anode terminal connected to the Mg anode, which is the sacrificial anode, a buried pipe terminal connected to the buried pipe, and a calculation circuit that periodically monitors the current flowing from the Mg anode to the buried pipe and calculates the remaining amount of electricity from this current value and the amount of electricity of the Mg anode, which is the measurement target and which has been input in advance.

[0005] According to the life prediction device described in Patent Document 3, an arithmetic circuit periodically monitors the value of the anticorrosion current that constantly flows from the Mg anode to the buried pipe based on the potential difference. From this value and the amount of electricity of the target Mg anode that has been input in advance, the amount of wear up to the present can be calculated, and the degree of wear and life of the Mg anode can be known.

[0006] Furthermore, a conventional technique for monitoring the wear of sacrificial anodes is known, for example, from Patent Document 4. In the cathodic protection monitoring system described in Patent Document 4, a sensing electrode made of the same metal as the underwater metallic structure is attached to the cathodic protected underwater metallic structure, and the sensing electrode and the underwater metallic structure are connected via an insulating lead wire and a zero-resistance current meter, thereby forming a cathodic protection current monitor. Then, multiple cathodic protection current monitors are installed on the underwater metallic structure, and the current data from each monitor is collected and monitored.

[0007] According to the cathodic protection monitoring system described in Patent Document 4, unlike conventional methods that use reference electrodes such as silver-silver chloride electrodes or saturated calomel electrodes to measure the potential of underwater metal structures, by directly measuring the anticorrosion current, it is possible to efficiently and effectively improve the safety and long-term durability of underwater metal structures in a cathodic protection state, and it is also said that it is possible to remotely and unmannedly monitor the anticorrosion status of underwater metal structures or the wear state of sacrificial anodes. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 5-171477 [Patent Document 2] Japanese Patent Application Publication No. 7-316851 [Patent Document 3] Japanese Patent Application Publication No. 6-294770 [Patent Document 4] Japanese Patent Application Publication No. 8-283969 Summary of the Invention [Problem to be solved by the invention]

[0009] In the prior art disclosed in Patent Documents 3 and 4, there is no problem if the wear rate of the sacrificial anode is approximately the same as the original design value. However, during long-term corrosion protection, factors such as changes in the environment surrounding the structure (e.g., water temperature, water pollution level, water resistivity, etc.), unexpected deterioration of the coating applied to the structure, and structural changes in the structure itself due to connections with other structures, can change beyond what was initially expected, and these changes can affect the lifespan of the sacrificial anode. Therefore, the prior art disclosed in Patent Documents 3 and 4 cannot accurately determine the wear state of the sacrificial anode.

[0010] The present invention has been made to solve such problems, and has as its object to make it possible to more accurately determine the state of consumption of a sacrificial anode. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems, the sacrificial anode structure of the present invention includes a sacrificial anode, a waterproof container which is a hollow container in which at least a portion of a body is embedded and which is configured to prevent water from entering from any location other than a through-hole opened at a predetermined position in the body, and a water intrusion sensor disposed inside the waterproof container. The through-hole is located at a position where the sacrificial anode is embedded inside the waterproof container and where the through-hole begins to become exposed from the dissolving surface of the sacrificial anode when the consumption amount of the sacrificial anode reaches a desired amount. [Effects of the Invention]

[0012] According to the present invention configured as described above, the sacrificial anode structure of the present invention is installed and used on a steel material to be protected from corrosion placed underwater. When the sacrificial anode reaches a desired level of wear, the through-hole is exposed from the dissolving surface of the sacrificial anode, causing water to enter the waterproof container through the through-hole, and this water intrusion is detected by the water intrusion sensor. Therefore, the detection operation of the water intrusion sensor makes it possible to know that the sacrificial anode has reached a desired level of wear. The degree of wear of the sacrificial anode varies depending on changes in the environment surrounding the sacrificial anode and structural changes in the sacrificial anode itself. However, because water intrusion into the waterproof container occurs depending on the actual wear state of the sacrificial anode due to these influences, it is possible to more accurately determine the wear state of the sacrificial anode. [Brief explanation of the drawings]

[0013] [Figure 1] 1A to 1C are diagrams illustrating an example of the configuration of a sacrificial anode structure according to a first embodiment. [Figure 2] 1 is a diagram illustrating a configuration example of a waterproof container according to a first embodiment. [Figure 3] FIG. 10 is a diagram showing a state in which the through-hole is exposed. [Figure 4] 3A and 3B are diagrams showing the state of a cable inside a body of a waterproof container according to the first embodiment. [Figure 5] 10A and 10B are diagrams illustrating an example of the configuration of a cap provided at the tip of a cable. [Figure 6] 1 is a diagram showing an example of the configuration of a consumption state determination system including a sacrificial anode structure according to a first embodiment. [Figure 7] 1 is a block diagram showing an example of the functional configuration of a measurement device according to a first embodiment. [Figure 8] 10A and 10B are diagrams illustrating an example of the configuration of a sacrificial anode structure according to a second embodiment. [Figure 9] 10A and 10B are diagrams showing modified examples of the sacrificial anode structure according to the second embodiment. [Figure 10] 10A and 10B are diagrams illustrating an example of the configuration of a sacrificial anode structure according to a third embodiment. [Figure 11] FIG. 10 is a block diagram showing an example of the functional configuration of a measurement device according to a third embodiment. [Figure 12] FIG. 10 is a diagram illustrating an example of the configuration of a waterproof container according to a fourth embodiment. [Figure 13] FIG. 10 is a block diagram showing an example of the functional configuration of a measurement device according to a fourth embodiment. [Figure 14] FIG. 10 is a diagram for explaining an example of notification according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] (First embodiment) A first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a diagram showing an example of the configuration of a sacrificial anode structure 1 according to the first embodiment. As shown in Fig. 1, the sacrificial anode structure 1 according to the first embodiment is configured to include a sacrificial anode 11, a core 12, a flat steel bent core 13, a waterproof container 14, and a cable 15 used as a water immersion sensor. The sacrificial anode structure 1 of this embodiment is used by attaching it to a steel material to be protected from corrosion that is placed underwater.

[0015] The sacrificial anode 11 is made of an aluminum alloy, zinc alloy, magnesium alloy, or the like, whose main component is a metal with a higher ionization tendency than the steel material to be protected from corrosion, and has, for example, a trapezoidal prism shape. The sacrificial anode 11 gradually dissolves itself through ionization in water attached to the steel material to be protected from corrosion, generating a protective current. This protective current flows into the steel material to be protected from corrosion, thereby providing a corrosion-inhibiting effect to the steel material to be protected from corrosion.

[0016] The core metal 12 is a steel bar disposed inside the sacrificial anode 11, and is disposed along the longitudinal direction of the trapezoid at approximately the center in the height direction of the trapezoidal column-shaped sacrificial anode 11. The core metal 12 can be made of, for example, a conductive stainless steel bar or a deformed steel bar.

[0017] Both ends of the core metal 12 are embedded inside the sacrificial anode 11, and flat steel bent core metal 13 is welded to both ends of this core metal 12. The flat steel bent core metal 13 has a gentle, roughly crank-shaped configuration with an angle larger than a right angle, and one end is welded to the end of the core metal 12. The flat steel bent core metal 13 protrudes from the longitudinal end face of the sacrificial anode 11 and is bent toward the lower base side of the sacrificial anode 11. The other end of the flat steel bent core metal 13 is welded to a channel steel 101, and the channel steel 101 is welded and fixed to the steel material 100 to be corrosion protected. As a result, the anticorrosion current generated from the sacrificial anode 11 returns to the sacrificial anode 11 via the path of the steel material to be protected 100 → channel steel 101 → flat steel bent core bar 13 → core bar 12 → sacrificial anode 11 or the path of the steel material to be protected 100 → channel steel 101 → flat steel bent core bar 13 → sacrificial anode 11.

[0018] While FIG. 1 illustrates a configuration in which a flat steel bent core 13 is connected to the core 12 and the sacrificial anode structure 1 is attached to the steel material 100 to be protected from corrosion using the bent core 13, the present invention is not limited to this. For example, the core 12 may be long enough to penetrate the sacrificial anode 11 in the longitudinal direction, with the portions protruding from both longitudinal end faces of the sacrificial anode 11 formed into a roughly crank shape, and the ends of the core 12 may be welded to channel steel 101 welded to the steel material 100 to be protected from corrosion. Alternatively, a simple flat steel bar without a crank shape may be used instead of the bent core 13. In this case, flat steel bars may be used to connect both ends of the core 12 embedded in the sacrificial anode 11 to the steel material 100 to be protected from corrosion, as shown in FIG. 1. Alternatively, flat steel bars may be used to connect both ends of the core 12, which has a length long enough to penetrate the sacrificial anode 11 in the longitudinal direction, to the steel material 100 to be protected from corrosion.

[0019] The waterproof container 14 is a hollow container fixed to the core metal 12 with at least a portion of the body 20 embedded inside the sacrificial anode 11, and is configured so that water does not enter from any location other than the through-hole 21 provided at a predetermined position in the body 20. The attachment position of the waterproof container 14 to the sacrificial anode 11 is, for example, the back side of the sacrificial anode 11 (the lower bottom side of the trapezoidal column shape). However, this is not limited to this, and the waterproof container 14 may be attached to any of the four faces other than the two end faces from which the flat steel bent core metal 13 protrudes.

[0020] 2 is a diagram showing an example of the configuration of the waterproof container 14. The body 20 of the waterproof container 14 is made of, for example, a flanged STPG (Steel Tube Pipe General) steel pipe. A steel plate 22 is welded to the lower end of the body 20, and for example, the steel plate 22 is welded to the core metal 12. A PVC closing flange 25 with a packing 24 sandwiched therebetween and a cable gland 26 attached thereto is attached to a flange 23 provided at the upper end of the body 20 with bolts 27 and nuts 28 as shown in FIG.

[0021] Although Fig. 2 shows a configuration in which the cross section of the body 20 is circular, this is not limited to this. In other words, the cross section of the body 20 may be polygonal or any other shape. A configuration using a flanged steel pipe, packing, and a closing flange is effective as a watertight structure. However, as long as the configuration does not allow water to enter from any location other than the through hole 21, it is not limited to the configuration shown in Fig. 2.

[0022] A through-hole 21 is provided at a predetermined position in the body 20, penetrating from the outside to the inside of the waterproof container 14. The through-hole 21 has an inner diameter of about several millimeters. For example, it may be about 3 mm. In the example shown in FIG. 2, two through-holes 21 are provided equidistant from the initial surface of the sacrificial anode 11 (the end surface of the unconsumed sacrificial anode 11). However, this number is merely an example, and the number may be one, three, or more. The through-hole 21 is provided at a position where it is embedded inside the sacrificial anode 11 and where it begins to become exposed from the dissolving surface of the sacrificial anode 11 when the consumption amount of the sacrificial anode 11 reaches a desired amount. The through-hole 21 may be polygonal or any other shape. It is sufficient that the shape allows water to enter through the through-hole 21 when the consumption amount of the sacrificial anode 11 reaches a desired amount.

[0023] FIG. 3 is a diagram showing a state in which the through-hole 21 is exposed. FIG. 3(a) shows a state in which the sacrificial anode 11 is not consumed (not dissolved) at all. As shown in FIG. 3(a), the through-hole 21 of the waterproof container 14 is embedded inside the sacrificial anode 11. FIG. 3(b) shows a state after the sacrificial anode 11 has been consumed. As the sacrificial anode 11 is consumed, the dissolving surface 11a of the sacrificial anode 11 gradually retreats from its original position (shown by the dotted line) to a position closer to the core metal 12, as indicated by arrow Y1 in FIG. 3(b). As a result, the through-hole 21 is exposed from the dissolving surface 11a of the sacrificial anode 11. When the through-hole 21 is exposed, water flows into the body 20 through the through-hole 21.

[0024] 3(b) shows a state in which the entire through-hole 21 is completely exposed from the dissolving surface 11a of the sacrificial anode 11. This shows a state in which exposure begins from the end of the through-hole 21, and the amount of exposure gradually increases until the entire through-hole 21 is finally exposed. In reality, when a portion of the through-hole 21 is exposed from the dissolving surface 11a of the sacrificial anode 11, water flows into the interior of the body 20 from the exposed portion.

[0025] When the sacrificial anode 11 is cast into the waterproof container 14, the molten metal hardly penetrates into the inside of the body 20 through the through-hole 21 due to its viscosity. Even if the molten metal does enter the inside of the body 20 during casting, it will quickly solidify and cause no problems. The material of the waterproof container 14 may be any material that can withstand the temperature (about 800°C) when the sacrificial anode 11 is cast, and may be metal, ceramic, or any other material.

[0026] Here, the sacrificial anode structure 1 may be used in either a vertical or horizontal orientation. Vertical orientation refers to the case where the longitudinal direction of the sacrificial anode 11 is in the vertical direction (vertical direction) (see FIG. 6). Horizontal orientation refers to the case where the longitudinal direction of the sacrificial anode 11 is in the horizontal direction (horizontal direction). Depending on whether it is used in a vertical or horizontal orientation, it is necessary to determine the position of the through-hole 21 through which water flows in. That is, by providing the through-hole 21 at a position that is at the top of the cross section of the body 20 (on the water surface side), it is possible to allow air to escape from inside the body 20 and make it easier for water to flow in.

[0027] When the sacrificial anode structure 1 is used in a vertical orientation, the waterproof container 14 may be attached anywhere from above (the water surface side) to below (the bottom side) the sacrificial anode 11. On the other hand, when the sacrificial anode structure 1 is used in a horizontal orientation, the waterproof container 14 may be attached anywhere from the left to the right of the sacrificial anode 11. However, because the sacrificial anode 11 dissolves faster at the ends than at the center, the timing at which water begins to seep into the body 20 differs depending on the position at which the waterproof container 14 is attached to the sacrificial anode 11. In other words, water begins to seep into the body 20 sooner when the waterproof container 14 is attached closer to the end of the sacrificial anode 11.

[0028] In general, sacrificial anodes 11 in water are gradually consumed starting from their surface. Therefore, the consumption rate of sacrificial anodes 11 at the time when they begin to be submerged can be set arbitrarily by adjusting the position of through-holes 21 drilled in waterproof containers 14 in which sacrificial anodes 11 are embedded. Here, we will explain how to calculate the vertical distance from the surface of core metal 12 placed inside sacrificial anode 11 to the dissolution surface of the consumed sacrificial anode 11.

[0029] Based on the idea that when the remaining rate of the sacrificial anode 11 becomes 10%, the length of the sacrificial anode 11 becomes 90% of its initial value (85% depending on the shape of the sacrificial anode 11) (this will be described later), the vertical distance from the surface of the core metal 12 to the dissolution surface of the consumed sacrificial anode 11 is calculated as follows, based on the remaining rate of the sacrificial anode 11 and the remaining rate of the length of the sacrificial anode 11.

[0030] (Remaining amount of sacrificial anode 11) = (cross-sectional area of ​​remaining sacrificial anode 11) × (remaining length of sacrificial anode 11), a×V0=(πr a 2 )×(b×L) (Approximate radius of remaining sacrificial anode 11) = (radius of core metal 12) + (vertical distance from the surface of core metal 12 to the dissolving surface of sacrificial anode 11), r a =d+e Therefore, e={(a×V o ) / (π×b×L)} 1 / 2 -d...(Formula 1) This becomes:

[0031] Here, the parameters are as follows: a: Remaining rate of sacrificial anode 11 [%] b: Remaining length of the sacrificial anode 11 [%] d: radius of core bar 12 [mm] e: Vertical distance from the surface of the core metal 12 to the dissolving surface of the sacrificial anode 11 [mm] r a : Approximate radius of remaining sacrificial anode 11 [mm] V0: Initial volume of the sacrificial anode 11 [mm 3 ] L: initial length of the sacrificial anode 11 [mm]

[0032] For example, the radius d of the core metal 12 is 8 mm, and the initial volume V of the sacrificial anode 11 is 90,000,000 mm. 3], when the initial length L of the sacrificial anode 11 is 1,000 mm, and the sacrificial anode 11 is consumed to 90% and the length of the sacrificial anode 11 is reduced by 10% (a = 0.1, b = 0.9), the vertical distance e from the surface of the core metal 12 to the dissolving surface of the sacrificial anode 11 is calculated to be e = 48.4 mm using the above (Equation 1). Therefore, if it is desired that water begin to penetrate into the body 20 after the sacrificial anode 11 is consumed to 90%, the through hole 21 should be positioned so that the end of the through hole 21 is located at a position where the vertical distance e from the surface of the core metal 12 is 48.4 mm.

[0033] Here, we will explain the idea that when the remaining rate of the sacrificial anode 11 reaches 10%, the length of the sacrificial anode 11 will be 90% of its initial value (85%, depending on the shape of the sacrificial anode 11). This is explained in "RECOMMENDED PRACTICE DNV-RP-B401 Edition May 2021" (Cathodic protection design p.38, 60). According to this, if the shape of the sacrificial anode 11 is a long slender stand-off type, the consumption of the sacrificial anode 11 reaches 90% when it has been consumed to 90% of its initial length. In other words, when the length of the sacrificial anode 11 has been consumed by 10%, the overall consumption of the sacrificial anode 11 will be 90%.

[0034] Here, a long slender stand-off type is a sacrificial anode 11 that satisfies L≧4r, where r is the equivalent radius of the sacrificial anode 11, expressed as r=c / 2π, where L is the length of the sacrificial anode 11 and c is the cross-sectional circumference. On the other hand, if L<4r, it is called a short slender stand-off type, and this is based on the idea that when the sacrificial anode's length is consumed by 10%, its consumption amount is 85%. By following this idea, it is possible to arbitrarily set the detection of the consumption amount of the sacrificial anode 11.

[0035] Returning to FIG. 1 , the cable 15 functions as a water intrusion sensor for detecting the occurrence of water intrusion into the body 20. The cable 15 is, for example, a two-core cable, and one end of each of the first core wire 151 and the second core wire 152 is electrically connected to a measuring device (details of which will be described later) for measuring potential difference or resistance. The other ends of the first core wire 151 and the second core wire 152 are disposed inside the waterproof container 14 in an open state so as to prevent electrical continuity between them. The cable 15 may be a copper wire having a base material made of a solid wire or a stranded wire, or may be one having a base material made of a metal other than copper. The first core wire 151 and the second core wire 152 may be made of different metals. Any conductor may be used as long as it is covered with an insulator.

[0036] 4A and 4B are diagrams showing the state of the cable 15 inside the body 20. For example, as shown in FIG. 4A, the cable 15 is inserted into the body 20 through a cable gland 26, and the end of the first core wire 151 and the end of the second core wire 152 are arranged in the hollow without contacting each other. Alternatively, as shown in FIG. 4B, the end of the first core wire 151 may be arranged in the hollow, while a crimp terminal (not shown) may be attached to the end of the second core wire 152, and the crimp terminal may be fixed with a bolt and nut to a metal fitting 141 welded to the inner wall of the body 20. This reliably prevents the end of the first core wire 151 and the end of the second core wire 152 from contacting each other.

[0037] 5, a non-conductive cap 155 may be provided on at least one end of the first core wire 151 and the second core wire 152. The base of the cap 155 is fixed to, for example, the first core wire 151 via a packing 156, while the tip is open, allowing water to flow into the cap 155. The tip of the first core wire 151 is surrounded by the cap 155 in a ring shape, and therefore does not come into contact with the tip of the second core wire 152.

[0038] As described above, before water flows into the body 20 through the through-hole 21, the end of the first core wire 151 and the end of the second core wire 152 are electrically insulated from each other, and the potential difference between them exhibits an unstable value of several millivolts or more, and the resistance is infinite. In contrast, when water flows into the body 20 through the through-hole 21, the end of the first core wire 151 and the end of the second core wire 152 become immersed in water. This causes a significant change in the potential difference or resistance between the end of the first core wire 151 and the end of the second core wire 152. That is, the potential difference represents the difference in natural potential between the metals of the first core wire 151 and the second core wire 152, and its value stabilizes. Furthermore, the resistance decreases to several tens of kΩ or less. As described above, the other ends of the first core wire 151 and the second core wire 152 are electrically connected to a measuring device, which can detect this change in potential difference or resistance.

[0039] The cable 15 may be a single-core wire. In this case, it is possible to detect water ingress into the body 20 by checking the potential difference or resistance between the steel material 100 to be corrosion protected and the single-core wire, or between the reference electrode and the single-core wire.

[0040] Fig. 6 is a diagram showing an example of the configuration of a wear state determination system including the sacrificial anode structure 1 configured as described above. As shown in Fig. 6, the wear state determination system is configured with the sacrificial anode structure 1 and a measuring device 2. As shown in Fig. 6, the sacrificial anode structure 1 is attached to a steel material 100 to be corrosion protected, which is placed underwater. The measuring device 2 is a device that measures the potential difference or resistance generated at the other end of the cable 15 (first core wire 151 and second core wire 152) placed inside the body 20 of the sacrificial anode structure 1. The sacrificial anode structure 1 is placed underwater, while the measuring device 2 is placed on land.

[0041] FIG. 7 is a block diagram showing an example of the functional configuration of the measurement device 2 according to the first embodiment. As shown in FIG. 7, the measurement device 2 has a consumption state determination unit 2a and a notification unit 2b as its functional configuration. These functional blocks 2a-2b can be configured using any of hardware such as a circuit, a DSP (Digital Signal Processor), or software. It is also possible for a portion to be configured using hardware or a DSP, and another portion to be configured using software. The portion configured using software is actually configured using a computer CPU, RAM, ROM, etc., and is realized by the operation of a program stored in a storage medium such as RAM, ROM, a hard disk, or semiconductor memory.

[0042] The wear state determination unit 2a sequentially measures the potential difference or resistance occurring at the ends of the first core wire 151 and the second core wire 152 at predetermined time intervals. The wear state determination unit 2a then determines the wear state of the sacrificial anode 11 based on changes in the measured potential difference or resistance. For example, the wear state determination unit 2a compares the most recent measurement value with the most recent measurement value, and detects that the wear amount of the sacrificial anode 11 has reached a desired amount when the potential difference changes from an unstable value of several millivolts or more to a stable value, or when the resistance changes from infinity to a stable value. Note that the lifespan of the sacrificial anode 11 can last several decades, so the measurement interval can be set taking this into consideration. Alternatively, measurements may be performed at any timing.

[0043] The notification unit 2b notifies the user that the sacrificial anode 11 has reached a predetermined consumption amount when the consumption state determination unit 2a detects that the consumption amount of the sacrificial anode 11 has reached a desired amount. The notification method is arbitrary. For example, an LED or other light-emitting element may be made to emit light. Alternatively, a message using characters or figures may be displayed on a display device. Alternatively, an alarm buzzer may be sounded, or a predetermined audio message may be output from a speaker.

[0044] 7 is shown as an example of the configuration of the measuring device 2, but the present invention is not limited to this. The measuring device 2 may simply be a voltmeter, recorder, or logger. Alternatively, the cable 15 may be connected to the measuring device 2 only when measuring the potential difference or resistance.

[0045] As described above in detail, in the first embodiment, the sacrificial anode structure 1 is configured to include the sacrificial anode 11, a hollow waterproof container 14 having at least a portion of its body 20 embedded inside the sacrificial anode 11, and a cable 15 serving as a water intrusion sensor disposed inside the waterproof container 14. The body 20 of the waterproof container 14 is provided with a through-hole 21 at a position where the cable is embedded inside the sacrificial anode 11 and where the cable begins to become exposed from the dissolving surface of the sacrificial anode 11 when the consumption amount of the sacrificial anode 11 reaches a desired amount. The cable 15 is also configured as a two-core cable, with one end of each of the two cores connected to the measuring device 2 and the other end disposed in an open state (insulated state) inside the body 20 of the waterproof container 14.

[0046] According to the first embodiment configured as described above, the sacrificial anode structure 1 of this embodiment is installed and used on the steel material 100 to be protected from corrosion that is placed underwater, and when the amount of consumption of the sacrificial anode 11 reaches a desired amount, the through hole 21 is exposed from the dissolving surface of the sacrificial anode 11 and is exposed to the water, causing water to enter the waterproof container 14 through the through hole 21. The occurrence of water entry into the waterproof container 14 is then detected by the measuring device 2 through a change in the potential difference or resistance that occurs between the two core wires 151, 152 of the cable 15 arranged inside the body 20.

[0047] Therefore, this detection operation makes it possible to know that the consumption amount of the sacrificial anode 11 has reached the desired amount. The degree of consumption of the sacrificial anode 11 varies depending on the influences of changes in the environment surrounding the sacrificial anode 11 and structural changes in the sacrificial anode 11 itself, but since water enters the waterproof container 14 depending on the actual consumption state of the sacrificial anode 11 due to these influences, it is possible to more accurately determine the consumption state of the sacrificial anode 11.

[0048] In the first embodiment, a configuration example in which the waterproof container 14 is fixed to the core metal 12 has been shown, but the present invention is not limited to this. That is, the waterproof container 14 does not necessarily have to have the body 20 fixed to the core metal 12. However, if the body 20 is made of metal and welded to the core metal 12, there is an advantage in that the sacrificial anode 11 can be easily cast.

[0049] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings. Fig. 8 is a diagram showing a configuration example of a sacrificial anode structure 1A according to the second embodiment. In Fig. 8, components having the same reference numerals as those shown in Fig. 1 have the same functions, and therefore, redundant explanations will be omitted here.

[0050] As shown in FIG. 8, the sacrificial anode structure 1A according to the second embodiment includes a sacrificial anode 11, a core metal 12, and a plurality of waterproof containers 14A. -1 ,14A -2 ,14A -3 (Hereinafter, these may be collectively referred to as a waterproof container 14A), and a cable 15A used as a water intrusion sensor. -1 ,15A -2 ,15A -3 (Hereinafter, these may be collectively referred to as cable 15A), conductive pillars 16, a cable 17, and a waterproof joint box 18. Although not shown in FIG. 8, flat steel bent core metals 13 similar to those in the first embodiment are connected to both ends of core metal 12.

[0051] In the second embodiment, a plurality of waterproof containers 14A -1 ,14A -2 ,14A -3 is fixed to the core metal 12 so as to be in a conductive state. This fixing method is the same as in the first embodiment, and the steel plate 22A welded to the lower end of the body 20A is welded to the core metal 12. -1 ,14A -2 ,14A -3Since the sacrificial anode 11 is electrically connected to the core metal 12, it is not essential that the sacrificial anode 11 is electrically connected to the core metal 12. However, if the sacrificial anode 11 is electrically connected, it is easier to cast the sacrificial anode 11. If the sacrificial anode 11 is not electrically connected, the waterproof container 14 may be damaged when the sacrificial anode 11 is worn out. -1 ,14A -2 ,14A -3 Since there is a possibility that the sacrificial anode 11 may come off, it is preferable that the sacrificial anode 11 is electrically conductive.

[0052] In the second embodiment, the body 20A is made of a steel pipe (for example, a thick steel electrical conduit) having a diameter approximately the same as that of the cable gland 26. That is, in the second embodiment, in order to embed a plurality of waterproof containers 14A and conductive columns 16 in a sacrificial anode 11 having the same volume as that of the first embodiment, each of the plurality of waterproof containers 14A is made thinner than the waterproof container 14 according to the first embodiment. The upper end of the waterproof container 14A is closed by the cable gland 26.

[0053] A through-hole 21A is provided at a predetermined position on the body 20A, and penetrates from the outside to the inside of the waterproof container 14A. -1 ,21A -2 ,21A -3 (Hereinafter, these may be collectively referred to as through holes 21A.) These through holes 21A are provided at positions where they are embedded inside the sacrificial anode 11, and where they begin to be exposed from the dissolving surface of the sacrificial anode 11 when the amount of consumption of the sacrificial anode 11 reaches a desired amount.

[0054] Multiple waterproof containers 14A -1 ,14A -2 ,14A -3 In the through hole 21A -1 ,21A -2 ,21A -3 The positions where the first waterproof container 14A is provided are different. -1 Through hole 21A -1 The second waterproof container 14A is provided at a distance t1 from the initial surface of the sacrificial anode 11. -2 Through hole 21A -2is provided at a position at a distance t2 (t1 < t2) from the initial surface of the sacrificial anode 11. The third waterproof container 14A -3 of the through-hole 21A -3 is provided at a position at a distance t3 (t2 < t3) from the initial surface of the sacrificial anode 11. For example, the distance t1 is the position where the consumption rate of the sacrificial anode 11 is 70%, the distance t2 is also 80%, and the distance t3 is also 90% where water immersion starts.

[0055] A plurality of waterproof containers 14A -1 , 14A -2 , 14A -3 The cable 15A arranged as a water immersion sensor in -1 , 15A -2 , 15A -3 are all single-core cables. One end of each is electrically connected to the measuring device 2 via the joint box 18, and the other end is in an open state inside the waterproof container 14A -1 , 14A -2 , 14A -3 is arranged inside. Since the internal space of the waterproof container 14A is narrower than that of the first embodiment, in order to prevent the tip of the cable 15A from contacting the inner wall of the waterproof container 14A and causing conduction, it is preferable to cover the tip of the cable 15A with the cap 155.

[0056] A plurality of waterproof containers 14A -1 , 14A -2 , 14A -3 are arranged at relatively close positions to each other. The third waterproof container 14A arranged at the end among them -3 At a position away from, the conductive columnar body 16 is fixed to the core metal 12 so as to be in a conductive state. The conductive columnar body 16 is, for example, round steel with male thread processing at the tip. Note that the conductive columnar body 16 does not necessarily have to be round steel, and for example, a steel pipe or the like may be used. Also, since the conductive columnar body 16 is also conductive through the sacrificial anode 11, it does not necessarily have to be conductive to the core metal 12. However, it is preferable that it is conductive because it facilitates casting of the sacrificial anode 11 and can prevent the sacrificial anode 11 from falling off when the consumption of the sacrificial anode 11 progresses.

[0057] One end of a cable 17 is connected to the conductive pillar 16, and the other end of the cable 17 is electrically connected to the measuring device 2 via a joint box 18. The multiple cables 15A, whose ends are arranged inside the bodies 20A of the multiple waterproof containers 14A, and the cable 17 connected to the conductive pillar 16 are connected to a multi-core cable 19 inside the joint box 18, and the multi-core cable 19 is connected to the measuring device 2 on land. The joint box 18 may also be installed on land.

[0058] In the second embodiment, before water flows into the body 20A through the through-hole 21A, the end of the cable 15A and the body 20A are electrically isolated from each other, exhibiting an unstable potential difference of several millivolts or more and an infinite resistance. In contrast, when water flows into the body 20A through the through-hole 21A, the cable 15A becomes immersed in water. This significantly changes the potential difference or resistance between the end of the cable 15A and the body 20A. The other end of the cable 15A is electrically connected to the measuring device 2 via the joint box 18. The body 20A is electrically connected to the conductive pillar 16 through the mandrel 12 and the sacrificial anode 11. The conductive pillar 16 is electrically connected to the measuring device 2 via the cable 17 and the joint box 18. This allows the measuring device 2 to detect the change in potential difference or resistance. The potential difference or resistance between the end of cable 15A and body 20A can also be detected by inserting a voltmeter or the like between the other end of cable 15A and steel material 100 to be corrosion protected.

[0059] In the second embodiment, the water intrusion into the inside of the body 20A is prevented by the first waterproof container 14A. -1 → Second waterproof container 14A -2 →Third waterproof container 14A -3 The measuring device 2 measures the change in potential difference or resistance due to the immersion in water in the first waterproof container 14A. -1 → Second waterproof container 14A -2 →Third waterproof container 14A -3Therefore, according to the second embodiment, it is possible to know in order that the consumption amount of the sacrificial anode 11 has reached the amounts of the distances t1, t2, and t3.

[0060] Furthermore, based on the values ​​of distances t1, t2, and t3 and the dates and times when the consumption of the sacrificial anode 11 reaches distances t1, t2, and t3, the relationship between the consumption of the sacrificial anode 11 and the elapsed time can be determined, and it is also possible to predict when a predetermined consumption amount will be reached. For example, from the date and time when the consumption of the sacrificial anode 11 reaches distance t1, it is possible to predict when the consumption of the sacrificial anode 11 will reach distance t2 or distance t3. It is also possible to predict the lifespan of the sacrificial anode 11.

[0061] 9, a plurality of waterproof containers 14A each having the same configuration as the waterproof container 14 described in the first embodiment and each having a through hole 21 at a different position may be used. -1 ',14A -2 ',14A -3 8. In this case, the conductive pillars 16 are not necessary. However, in this case, the volume of the sacrificial anode 11 is smaller than that of the configuration in FIG. 8, so the configuration in FIG. 8 is more preferable.

[0062] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to the drawings. Fig. 10 is a diagram showing an example of the configuration of a sacrificial anode structure 1B according to the third embodiment. In Fig. 10, components having the same reference numerals as those shown in Fig. 1 have the same functions, and therefore redundant explanations will be omitted here.

[0063] As shown in Fig. 10, a sacrificial anode structure 1B according to the third embodiment includes a sacrificial anode 11, a core 12, a flat steel bent core 13, a waterproof container 14B, a cable 15B that functions as a water intrusion sensor, and a conductive drainage bar 31. One end of the drainage bar 31 is connected to the steel material 100 to be protected from corrosion by a drainage point fitting 32 at a location different from the channel steel 101. The other end of the drainage bar 31 is inserted into the waterproof container 14B and fixed by a penetration fitting 33. The joints at both ends of the drainage bar 31 may be waterproofed with, for example, an underwater curing epoxy resin.

[0064] In the third embodiment, the channel steel 101 is insulated from the flat steel bent core 13 by an insulating plate 102 made of, for example, PVC. Therefore, the anticorrosion current generated from the sacrificial anode 11 flows into the steel material 100 to be protected from corrosion, and is led out to the waterproof container 14B via the drainage bar 31. The drainage bar 31 functions as a conductive path that leads the anticorrosion current into the inside of the waterproof container 14B.

[0065] Inside the waterproof container 14B, wiring 34 is provided that electrically connects the drainage bar 31 to the steel plate 22, and a circuit is formed including this wiring 34, in which the anticorrosive current generated from the sacrificial anode 11 returns to the sacrificial anode 11. A part of the wiring 34 is formed by a shunt resistor 35. With this circuit, the anticorrosion current generated from the sacrificial anode 11 returns to the sacrificial anode 11 via the following path: the steel material to be protected 100 → drain point fitting 32 → drain bar 31 → wiring 34 (including shunt resistor 35) → shunt connection part 36 → steel plate 22 → core wire 12 → sacrificial anode 11, the steel material to be protected 100 → drain point fitting 32 → drain bar 31 → wiring 34 → shunt connection part 36 → steel plate 22 → sacrificial anode 11, or the steel material to be protected 100 → drain point fitting 32 → drain bar 31 → wiring 34 → shunt connection part 36 → steel plate 22 → body 20B → sacrificial anode 11.

[0066] Cable 15B is a three-core cable, with two cores 151B and 152B for measuring the protective current of sacrificial anode 11 and the other core 153B for detecting wear of sacrificial anode 11. One end of each of cores 151B, 152B, and 153B of cable 15B is electrically connected to onshore measuring device 2B (details of which will be described later using FIG. 11). Meanwhile, the other end of each of the two cores 151B and 152B for measuring the protective current is electrically connected to both ends of shunt resistor 35 on the circuit through which the protective current generated from sacrificial anode 11 returns to the sacrificial anode 11. The other end of core 153B for wear detection is disposed in an open state inside waterproof container 14B. In the example of FIG. 10, the other end of each of the two cores 151B and 152B for measuring the protective current is electrically connected to both ends of shunt resistor 35. The other end of the wear detection core 153B is covered with a cap 155.

[0067] In the third embodiment, the anticorrosion current passing through the shunt resistor 35 is measured by an on-shore measuring device 2B from the potential difference between the first core wire 151B and the second core wire 152B for measuring the anticorrosion current, which are connected to both ends of the shunt resistor 35. The measuring device 2B also measures the potential difference or resistance occurring between the end of the third core wire 153B and the end of the first core wire 151B or the second core wire 152B, and the wear state of the sacrificial anode 11 is determined from changes in the measured value. As described above, the potential difference or resistance occurring between the end of the third core wire 153B and the body 20B of the waterproof container 14B can also be detected by inserting a voltmeter or the like between the other end of the third core wire 153B and the steel material 100 to be protected from corrosion.

[0068] A through-hole 21 that penetrates from the outside to the inside of the waterproof container 14B is provided at a predetermined position in the body 20B of the waterproof container 14B. In the third embodiment, before water flows into the inside of the body 20B from the through-hole 21, the end of the third core wire 153B for wear detection is electrically insulated from the other two core wires 151B and 152B, and the potential difference therebetween exhibits an unstable value of several millivolts or more, and the resistance is infinity.

[0069] In contrast, when water flows into the interior of body 20B through through-hole 21, all three core wires 151B, 152B, and 153B become immersed in water. As a result, the potential difference or resistance between third core wire 153B and first core wire 151B or between third core wire 153B and second core wire 152B changes significantly compared to before the immersion in water. Measuring device 2B detects this change in potential difference or resistance.

[0070] Fig. 11 is a block diagram showing an example of the functional configuration of a measuring device 2B according to the third embodiment. In Fig. 11, components with the same reference numerals as those shown in Fig. 7 have the same functions, and therefore redundant explanations will be omitted here. As shown in Fig. 11, the measuring device 2B has, as its functional configuration, a wear state determination unit 2a, a notification unit 2b', and a protective current measurement unit 2c. These functional blocks 2a to 2c can be configured using any of hardware such as a circuit, DSP, or software. It is also possible for some to be configured using hardware or DSP, and other parts to be configured using software.

[0071] The consumption state determination unit 2a measures, for example, the potential difference or resistance occurring at the ends of the first core wire 151B and the third core wire 153B for consumption detection sequentially at predetermined time intervals or at any timing, and determines the consumption state of the sacrificial anode 11 (that the consumption amount of the sacrificial anode 11 has reached a desired amount) based on changes in the measured potential difference or resistance value.Then, the determination result is notified to the notification unit 2b'.

[0072] The anticorrosion current measuring unit 2c measures the anticorrosion current by detecting the potential difference generated across the shunt resistor 35 at each end of the first core wire 151B and the second core wire 152B for measuring the anticorrosion current. The anticorrosion current measuring unit 2c sequentially measures the anticorrosion current at predetermined time intervals and sequentially outputs the measurement results to the reporting unit 2b'.

[0073] When the consumption state determination unit 2a detects that the consumption amount of the sacrificial anode 11 has reached a desired amount, the notification unit 2b' notifies that the sacrificial anode 11 has reached a predetermined consumption amount. In addition, the notification unit 2b' displays the value of the anticorrosion current measured by the anticorrosion current measurement unit 2c on the display device.

[0074] According to the third embodiment configured as described above, the wear amount of the sacrificial anode 11 can be calculated according to a predetermined function using the wear current as a variable by measuring the wear current over time from the potential difference between the two core wires 151B, 152B connected to both ends of the shunt resistor 35 for wear current measurement. Furthermore, the wear state of the sacrificial anode 11 can be determined from changes in the potential difference or resistance between the end of the third core wire 153B, which is disposed within the body 20 of the waterproof container 14B for wear detection, and the first core wire 151B or the second core wire 152B. Furthermore, when water seeps in through the through hole 21 and it is detected that the wear amount of the sacrificial anode 11 has reached a desired amount, it is possible to verify the wear amount of the sacrificial anode 11 by comparing it with the wear amount calculated from the wear current measured over time.

[0075] Although the third embodiment described an example in which a three-core cable is used as cable 15B, a four-core cable may also be used. In this case, first core wire 151B and second core wire 152B are used to measure the anticorrosive current of sacrificial anode 11, and third core wire 153B and fourth core wire (not shown) are used to detect wear of sacrificial anode 11. One end of each of third core wire 153B and fourth core wire is electrically connected to measuring device 2B, and the other ends are disposed in body 20B of waterproof container 14B in an open state so as not to be electrically connected to each other. Wear state determining unit 2a measures the potential difference or resistance occurring at the end of third core wire 153B and the end of the fourth core wire.

[0076] In addition, although the third embodiment also shows an example of a configuration in which the waterproof container 14B is fixed to the core metal 12, the present invention is not limited to this. That is, the present invention is not limited to a sacrificial anode structure 1B of a type in which the sacrificial anode 11 is supported by the core metal 12, and a configuration in which the body 20B is not fixed to the core metal 12 may also be used.

[0077] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 12 is a diagram showing an example of the configuration of a waterproof container 14C according to the fourth embodiment. In Fig. 12, components with the same reference numerals as those shown in Fig. 10 have the same functions, and therefore redundant explanations will be omitted here. In the fourth embodiment, as in Fig. 10, the sacrificial anode structure including the waterproof container 14C also includes a flat steel bent core 13 and a drainage bar 31.

[0078] 12, the waterproof container 14C according to the fourth embodiment has a first space SP1 in which the wiring 34 and the shunt resistor 35 are provided, and a second space SP2 in which the through-hole 21 is provided. The wiring 34 and the shunt resistor 35 are not provided in the second space SP2, and only a third core wire 153C of a cable 15C (described later) is disposed therein. The second space SP2 is disposed closer to a deeper portion of the sacrificial anode 11 (closer to the core metal 12) than the first space SP1. The first space SP1 and the second space SP2 are separated by a steel plate 37, and are configured to be watertight.

[0079] When a waterproof container 14C having such a configuration is used, the anticorrosion current generated from the sacrificial anode 11 returns to the sacrificial anode 11 via the following path: steel material 100 to be protected from corrosion → drain point fittings 32 → drain bar 31 → wiring 34 (including shunt resistor 35) → shunt connection part 36 → steel plate 37 → body 20C → steel plate 22 → core wire 12 → sacrificial anode 11, a path that flows directly from the steel plate 37 to the sacrificial anode 11, a path that flows directly from the body 20C to the sacrificial anode 11, or a path that flows directly from the steel plate 22 to the sacrificial anode 11.

[0080] Cable 15C is a four-core cable, with two cores 151C and 152C for measuring the anticorrosive current of sacrificial anode 11, and the other cores 153C and 154C for detecting wear and water ingress of sacrificial anode 11. One end of each of cores 151C to 154C of cable 15C is electrically connected to onshore measuring device 2C (details of which will be described later using FIG. 13). The other end of each of first core 151C and second core 152C for measuring the anticorrosive current is electrically connected to two points (both ends of shunt resistor 35) on the circuit through which the anticorrosive current generated from sacrificial anode 11 returns to sacrificial anode 11.

[0081] The other end of the third core wire 153C for wear detection is disposed in an open state inside the second space SP2 of the waterproof container 14C. As shown in Fig. 12, the third core wire 153C is passed from the first space SP1 to the second space SP2 via a cable gland 38 attached to a steel plate 37, so that water does not enter this area. The other end of the fourth core wire 154C for water entry detection is disposed in an open state inside the first space SP1. The ends of the third core wire 153C and the fourth core wire 154C are covered with caps 155.

[0082] In the fourth embodiment, as in the third embodiment, the anticorrosion current passing through the shunt resistor 35 is measured by an on-shore measuring device 2C from the potential difference between the first core wire 151C and the second core wire 152C for measuring the anticorrosion current, which are connected to both ends of the shunt resistor 35. The potential difference or resistance occurring at the end of the third core wire 153C is also measured by the measuring device 2C, and the wear state of the sacrificial anode 11 is determined from changes in the measured value. Furthermore, the potential difference or resistance occurring at the end of the fourth core wire 153C is measured by the measuring device 2C, and flooding of the first space SP1 is detected from changes in the measured value.

[0083] A through-hole 21 that penetrates from the outside of the waterproof container 14C to the inside of the second space SP2 is provided at a predetermined position in the body 20C of the waterproof container 14C. In the fourth embodiment, before water flows into the second space SP2 through the through-hole 21, the end of the third core wire 153C for wear detection is electrically insulated from the steel plate 37, and is therefore electrically insulated from the first core wire 151C and the second core wire 152C that are electrically connected to the steel plate 37. Therefore, the potential difference between the third core wire 153C and the first core wire 151C or between the third core wire 153C and the second core wire 152C exhibits an unstable value of several millivolts or more, and the resistance exhibits infinity.

[0084] In contrast, when water flows into the second space SP2 from through hole 21, the space between third core wire 153C and steel plate 37 becomes submerged in water. This causes a significant change in the potential difference or resistance between third core wire 153C and first core wire 151C or between third core wire 153C and second core wire 152C compared to before the water entered. Measuring device 2C detects this change in potential difference or resistance.

[0085] Furthermore, in the fourth embodiment, unless water flows into the first space SP1 due to damage to the waterproof container 14C or poor watertightness, the end of the fourth core wire 154C for detecting water intrusion, which is arranged in the first space SP1, is electrically insulated from the first core wire 151C and the second core wire 152C arranged in the same first space SP1, and the potential difference therebetween shows an unstable value of several millivolts or more, and the resistance shows ∞.

[0086] In contrast, when water flows into the first space SP1, all three core wires 151C, 152C, and 154C are immersed in water. As a result, the potential difference or resistance between the fourth core wire 154C and the first core wire 151C or between the fourth core wire 154C and the second core wire 152C changes significantly compared to before the water entered the space. The measuring device 2C detects this change in potential difference or resistance.

[0087] FIG. 13 is a block diagram showing an example of the functional configuration of a measuring device 2C according to the fourth embodiment. In FIG. 13, components assigned the same reference numerals as those shown in FIG. 11 have the same functions, and therefore redundant explanations will be omitted here. As shown in FIG. 13, the measuring device 2C has, as its functional configuration, a wear state determination unit 2a, a notification unit 2b", a protective current measurement unit 2c, and a flood detection unit 2d. These functional blocks 2a to 2d can be configured using any of hardware such as circuits, DSP, or software. It is also possible for some to be configured using hardware or DSP, and other parts to be configured using software.

[0088] The consumption state determination unit 2a measures, for example, the potential difference or resistance occurring at the ends of the first core wire 151C and the third core wire 153C for consumption detection sequentially at predetermined time intervals or at any timing, and determines the consumption state of the sacrificial anode 11 (that the amount of consumption of the sacrificial anode 11 has reached a desired amount) based on changes in the value of the measured potential difference or resistance. Then, it notifies the notification unit 2b'' of the determination result.

[0089] The anticorrosion current measuring unit 2c measures the anticorrosion current from the potential difference generated at each end (both ends of the shunt resistor 35) of the first core wire 151C and the second core wire 152C for measuring the anticorrosion current. The anticorrosion current measuring unit 2c sequentially measures the anticorrosion current at predetermined time intervals and sequentially outputs the measurement results to the reporting unit 2b".

[0090] The water intrusion detection unit 2d measures, for example, the potential difference or resistance occurring at the ends of the first core wire 151C and the fourth core wire 154C for water intrusion detection sequentially at predetermined time intervals or at any timing, and detects water intrusion into the first space SP1 based on changes in the measured potential difference or resistance. Then, it notifies the notification unit 2b'' of the detection result.

[0091] The notification unit 2b" notifies that the sacrificial anode 11 has reached a predetermined amount of consumption when the consumption state determination unit 2a detects that the amount of consumption of the sacrificial anode 11 has reached a desired amount. The notification unit 2b" also displays the value of the anticorrosion current measured by the anticorrosion current measurement unit 2c on the display device. The notification unit 2b" also notifies that flooding has occurred when the flooding detection unit 2d detects that flooding has occurred in the first space SP1.

[0092] 14, the measuring device 2C includes a display device 41 for displaying the anticorrosion current, an LED 42 for informing of anode consumption, and an LED 43 for informing of the occurrence of flooding, and constantly displays the anticorrosion current on the display device 41. Furthermore, when it is detected that the sacrificial anode 11 has reached a desired consumption amount, the LED 42 is turned on, and when flooding into the first space SP1 is detected, the LED 43 is turned on.

[0093] According to the fourth embodiment configured as described above, by making the waterproof container 14C a two-layer structure of the first space SP1 and the second space SP2, it is possible to separately detect the wear state of the sacrificial anode 11 and the occurrence of water intrusion into the first space SP1 in which the wiring 34 and the shunt resistor 35 are arranged. By detecting the occurrence of water intrusion into the first space SP1, it is possible to know that the shunt resistor 35 is in an unusable state.

[0094] Although the fourth embodiment has been described as an example in which a four-core cable is used as cable 15C, a five-core cable may also be used. In this case, first core wire 151C and second core wire 152C are used to measure the anticorrosion current of sacrificial anode 11, and third core wire 153C and fifth core wire (not shown) are arranged in an insulated state in second space SP2 and are used to detect wear of sacrificial anode 11. Wear state determiner 2a measures the potential difference or resistance generated at the end of third core wire 153C and the end of the fifth core wire.

[0095] Furthermore, in the fourth embodiment, a configuration example in which the waterproof container 14C is fixed to the metal core 12 has been shown, but the present invention is not limited to this. That is, the present invention is not limited to the sacrificial anode structure 1C of the type in which the sacrificial anode 11 is supported by the metal core 12, and the body 20C may not be fixed to the metal core 12.

[0096] In the first to fourth embodiments, examples have been described in which cables 15, 15A to 15C are used as water immersion sensors, but the present invention is not limited to this. That is, water immersion sensors are not limited to types that measure the potential difference or resistance between two electrodes. For example, a water immersion sensor that utilizes a mechanism in which, when water enters the sensor, a water absorbent material expands, bending an optical fiber or other optical fiber core, thereby increasing loss, may be used.

[0097] Furthermore, the above-described embodiments are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be carried out in various forms without departing from the gist or main features thereof. [Explanation of symbols]

[0098] 1, 1A, 1B Sacrificial anode structure 2,2A,2B,2C measuring device 2a Consumption state determination unit 2b, 2b', 2b" Notification section 2c Anticorrosion current measurement section 2d Water ingress detection unit 11 Sacrificial anode 12 Core 13 Flat steel bending core 14,14A,14B,14C Waterproof container 15, 15A, 15B, 15C Cable (Water Intrusion Sensor) 16 Conductive column 17 Cable 18 Joint Box 19 Multi-core cable 20, 20A, 20B, 20C fuselage 21,21A through hole 22,21A steel plate 31 Drainage bar (conduit) 34 Wiring 35 Shunt resistor

Claims

1. A sacrificial anode structure to be attached to a steel material to be protected against corrosion, comprising: A sacrificial anode; A waterproof container that is a hollow container in which at least a part of a body is buried inside the sacrificial anode and is configured so that water does not enter from any part other than a through hole provided at a predetermined position of the body; a water ingress sensor disposed inside the waterproof container; The through hole is provided at a position embedded inside the sacrificial anode and at a position that begins to be exposed from the dissolving surface of the sacrificial anode when the consumption amount of the sacrificial anode reaches a desired amount. A sacrificial anode structure comprising:

2. The sacrificial anode structure according to claim 1, characterized in that the water immersion sensor is a cable having one end electrically connected to a measuring device and the other end open and placed inside the waterproof container.

3. The sacrificial anode structure described in claim 2, characterized in that the cable serving as the water immersion sensor is a two-core cable, one end of each of the first core wire and the second core wire is electrically connected to the measuring device, and the cable is placed inside the waterproof container in an open state so that the other ends of the first core wire and the second core wire are not electrically connected to each other.

4. A plurality of the waterproof containers having the through holes embedded in the sacrificial anode at different positions; A conductive columnar body embedded inside the sacrificial anode; a cable electrically connecting the conductive columnar body and the measuring device; The cables as the water intrusion sensors arranged in the plurality of waterproof containers are single-core cables, one end of which is electrically connected to the measuring device, and the other end of which is open and arranged inside the waterproof container.

3. A sacrificial anode structure as defined in claim 2.

5. 3. The sacrificial anode structure according to claim 2, further comprising a plurality of waterproof containers each having a through hole at a different position.

6. The cable as the water ingress sensor is a cable with three or more cores, two cores are used for measuring the anticorrosive current of the sacrificial anode, and the other cores are used for detecting wear of the sacrificial anode, One end of each core wire is electrically connected to the measuring device, while the other end of each of the two core wires for measuring the anticorrosive current is electrically connected to both ends of a shunt resistor on a circuit in which the anticorrosive current generated from the sacrificial anode returns to the sacrificial anode, and the other end of the core wire for detecting wear is disposed inside the waterproof container in an open state.

3. A sacrificial anode structure as defined in claim 2.

7. The circuit is configured using a conductive path electrically connected to the steel material to be protected from corrosion and wiring provided inside the waterproof container.

7. A sacrificial anode structure as defined in claim 6.

8. the waterproof container has a first space in which the wiring is provided and a second space in which the wiring is not provided and in which the through hole is provided, the second space is disposed closer to a deeper portion of the sacrificial anode than the first space, and the first space and the second space are configured so that they are not flooded with water; The cable as the water ingress sensor is a cable having four or more cores, two cores are used for measuring the anticorrosive current of the sacrificial anode, and the other cores are used for detecting wear of the sacrificial anode and detecting water ingress, One end of each core wire is electrically connected to the measuring device, while the other end of each of the two core wires for measuring the anticorrosive current is electrically connected to both ends of a shunt resistor on a circuit in which the anticorrosive current generated from the sacrificial anode returns to the sacrificial anode, the other end of the core wire for detecting wear is disposed inside the second space in an open state, and the other end of the core wire for detecting water intrusion is disposed inside the first space in an open state.

8. A sacrificial anode structure as claimed in claim 7.

9. A sacrificial anode structure according to any one of claims 2 to 5; a measuring device for measuring a potential difference or resistance occurring at the other end of the cable, The measuring device includes a consumption state determination unit that determines the consumption state of the sacrificial anode based on a change in the potential difference or resistance value. A system for determining the wear state of a sacrificial anode.

10. The sacrificial anode structure according to claim 6 ; a measuring device for measuring a potential difference or resistance occurring at the other end of the cable, The measuring device is a corrosion protection current measuring unit that detects the potential difference generated across the shunt resistor for measuring the corrosion protection current at the other end of the two core wires and measures the corrosion protection current; a wear state determination unit that determines a wear state of the sacrificial anode based on a change in the potential difference or resistance value generated at the other end of the wear detection core wire. A system for determining the wear state of a sacrificial anode.

11. The sacrificial anode structure of claim 8; a measuring device for measuring a potential difference or resistance occurring at the other end of the cable, The measuring device is a corrosion protection current measuring unit that detects the potential difference generated across the shunt resistor for measuring the corrosion protection current at the other end of the two core wires and measures the corrosion protection current; a wear state determination unit that determines a wear state of the sacrificial anode based on a change in the potential difference or resistance value generated at the other end of the wear detection core wire; a water ingress detection unit that detects water ingress into the first space based on a change in the potential difference or resistance value generated at the other end of the water ingress detection core wire. A system for determining the wear state of a sacrificial anode.

12. A method for determining the wear state of a sacrificial anode, in the wear state determination system described in claim 9, characterized in that the potential difference or resistance generated at the other end of the cable is measured by the measuring device, and the wear state of the sacrificial anode is determined based on the change in the value of the measured potential difference or resistance.

13. A method for determining the wear state of a sacrificial anode, in the wear state determination system described in claim 10, characterized in that the potential difference generated across both ends of the shunt resistor connected to the core wire for measuring the anticorrosive current is detected to measure the anticorrosive current, and the wear state of the sacrificial anode is determined based on a change in the potential difference or resistance value generated at the other end of the core wire for detecting wear.

14. In the wear state determination system described in claim 11, a method for determining the wear state of a sacrificial anode, characterized in that the potential difference generated across both ends of the shunt resistor connected to the core wire for measuring the anticorrosive current is detected to measure the anticorrosive current, the wear state of the sacrificial anode is determined based on a change in the potential difference or resistance value generated at the other end of the core wire for detecting wear, and water ingress into the first space is detected based on a change in the potential difference or resistance value generated at the other end of the core wire for detecting water ingress.

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