Auxiliary anode device and cathode protection system

Abstract

The utility model provides an auxiliary anode device and a cathode protection system, and belongs to the technical field of corrosion and protection. The auxiliary anode device comprises an anode body, a cathode circular tube and an insulating circular tube, the insulating round pipe comprises a pipe body, and an upper pipe cap and a lower pipe cap which are respectively sleeved at two ends of the pipe body; the upper pipe cap is provided with an anode cable threading pipe, a cathode cable threading pipe and an exhaust water inlet pipe; the cathode circular tube is arranged between the anode body and the inner wall of the tube body, the cathode circular tube is connected with a cathode cable, and the cathode cable penetrates through a cathode cable threading tube; one end of the anode body is connected with an anode cable; and the anode cable penetrates through the anode cable threading pipe. According to the auxiliary anode device and the cathode protection system disclosed by the utility model, the simultaneous electrochemical corrosion protection on the inner wall or the outer wall of a metal pipeline or a metal container can be realized, the comprehensiveness and the effect of cathode protection are obviously improved, and the service life of a metal structure is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of corrosion and protection technology, specifically to an auxiliary anode device and a cathodic protection system. Background Technology

[0002] Metal pipes and containers play a vital role in industrial production, urban water supply, and oil and gas transportation. However, these metal structures are exposed to complex natural environments for extended periods, making them highly susceptible to electrochemical corrosion. This corrosion leads to reduced structural strength, shortened service life, and even safety accidents. Therefore, effectively preventing electrochemical corrosion of metal pipes and containers has become a pressing technical challenge.

[0003] Traditional electrochemical corrosion protection methods mainly include coating protection, cathodic protection, and anodic protection. Among them, cathodic protection is widely used due to its significant effect and ease of operation. The basic principle of cathodic protection is to apply a cathodic current to the protected metal structure, causing its surface potential to shift negatively, thereby reducing the electrochemical corrosion rate of the metal.

[0004] Cathodic protection technology mainly includes impressed current cathodic protection and sacrificial anode cathodic protection. Sacrificial anode cathodic protection primarily uses a metal (such as zinc or aluminum) or alloy with a more negative potential than the protected metal as the anode, connected to the protected metal structure to form a galvanic cell. In a corrosive medium, the anode metal preferentially undergoes oxidation and is consumed, thus protecting the connected metal structure from corrosion. However, this method has drawbacks such as limited driving potential, non-adjustable protective current, and rapid anode consumption. Currently, impressed current cathodic protection is a commonly used method. This method uses an external DC power supply, connecting the protected metal structure to the negative terminal of the power supply, making it the cathode; simultaneously, the positive terminal of the power supply is connected to an auxiliary anode, making it the anode. In the electrolyte solution, current flows from the anode to the cathode, providing cathodic protection to the protected metal structure. However, for equipment with internal and external walls, such as metal pipes and containers, due to the uneven distribution of current in the metal structure and the influence of the electrolyte solution on current transmission, traditional impressed current cathodic protection methods often struggle to achieve simultaneous protection of both the internal and external walls.

[0005] Therefore, it is of great significance to develop an auxiliary anode device and a cathodic protection system that can simultaneously protect the inner and outer walls of metal pipes and metal containers from electrochemical corrosion. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model discloses an auxiliary anode device and a cathodic protection system, which can simultaneously protect the inner and outer walls of metal pipes and metal containers from electrochemical corrosion.

[0007] To achieve the above technical objectives, on the one hand, this utility model proposes an auxiliary anode device, including an anode body, a cathode tube, and an insulating tube;

[0008] The insulating round tube includes a tube body, an upper tube cap and a lower tube cap respectively fitted on both ends of the tube body, and the upper tube cap is provided with an anode cable conduit, a cathode cable conduit, and an exhaust and water inlet pipe;

[0009] The cathode tube is disposed between the anode body and the inner wall of the tube body, the cathode tube is connected to the cathode cable, and the cathode cable passes through the cathode cable conduit;

[0010] One end of the anode body is connected to an anode cable, and the anode cable is threaded through the anode cable conduit.

[0011] Furthermore, the exhaust and water inlet pipes are located at the edge of the upper cap, and there can be one or more exhaust and water inlet pipes. Independent exhaust and water inlet pipes ensure the discharge of excess gas, automatically maintain moisture, and guarantee stable device performance. Regardless of whether the auxiliary anode device is placed vertically or horizontally, the location of the exhaust and water inlet pipes at the edge of the upper cap allows for smoother gas discharge, preventing gas accumulation inside the device and reducing the risk of performance degradation or malfunction due to increased gas pressure. The design of providing one or more exhaust and water inlet pipes allows for flexible configuration of the device according to actual needs.

[0012] Furthermore, the anode body comprises multiple anode body units, with any two adjacent anode body units separated by an insulating support component; and / or, the anode body is either rod-shaped or strip-shaped. The anode body is composed of multiple anode body units, and any two adjacent anode body units are separated by an insulating support component. This separate, independent anode body design ensures electrical insulation between anode body units, preventing short circuits between anode body units. When one anode body unit fails or is damaged, the other anode body units can still operate normally, thereby avoiding the failure of the entire auxiliary anode device due to damage to any single anode body unit and extending the service life of the device.

[0013] Furthermore, the inner cavity of the insulating circular tube is filled with non-metallic material, which effectively prevents electrochemical corrosion and extends the life of the device.

[0014] Furthermore, the bottom of the cathode tube is provided with a through hole. This hole is pre-cut before installation at the bottom of the cathode tube. Its main function is to connect the cavity between the anode body and the inner wall of the cathode tube, and between the outer wall of the cathode tube and the inner wall of the tube, which facilitates electron conduction and improves the uniformity of current distribution.

[0015] Furthermore, the auxiliary anode device also includes insulating support tubes, which are circumferentially distributed between the inner wall of the tube body and the outer wall of the cathode tube. The circumferentially distributed insulating supports ensure that the cathode tube remains centered within the tube body, effectively preventing displacement or deformation of the cathode tube due to water flow, sediment, or other external factors. The insulating supports not only provide physical support but also serve as electrical isolation. They prevent current loss through unintended paths (such as direct contact between the tube body and the cathode tube), thereby reducing current loss.

[0016] Furthermore, the anode cable is detachably connected to the anode body; and / or, the cathode cable is welded or bolted to the cathode tube.

[0017] Furthermore, the insulating circular tube is a circular tube made of synthetic resin; and / or, the cathode circular tube is a circular tube made of carbon steel. The use of synthetic resin in the insulating circular tube reduces the soil voltage gradient under high voltage conditions, protecting the safety of nearby people and animals, and is more suitable for shallow burial to reduce the initial investment in the project.

[0018] On the other hand, this utility model also provides a cathodic protection system comprising at least one of the above-mentioned auxiliary anode devices, and further comprising a potentiostat and an auxiliary cathode device, wherein:

[0019] The positive output terminal of the potentiostat is connected to the anode cable of the auxiliary anode device, and the negative output terminal of the potentiostat is connected to the wall of the protected metal pipe or the wall of the metal container; the reference terminal of the potentiostat is connected to the solid reference electrode of the auxiliary cathode device; the zero terminal of the potentiostat is connected to the surface of the protected metal pipe or the metal container.

[0020] The cathode cable of the auxiliary anode device is connected to the anode terminal of the auxiliary cathode device;

[0021] The auxiliary cathode device includes a metal housing and an insulated connecting pipe. An anode terminal is provided on the metal housing, a solid reference electrode is provided on the metal housing, and an insulating layer is coated on the outer wall of the metal housing.

[0022] One end of the connecting pipe is insulated from the metal shell and connected to the wall of the protected metal pipe or the wall of the metal container, so that the electrolyte solution in the protected metal pipe or the metal container is introduced into the space formed by the metal shell through the connecting pipe.

[0023] Existing technologies often only provide cathodic protection for the outer or inner walls of metal pipes or containers. However, the auxiliary anode device of this invention can simultaneously provide electrochemical corrosion protection for both the inner and outer walls of metal pipes or containers. Specifically, when the potentiostat is energized, electrons flow through the electrolyte solution in the protected metal pipe or container to the auxiliary cathode device. The auxiliary cathode device connects to the cathode cable of the auxiliary anode device of this invention and is conducted to the cathode tube. Electrons are then conducted through the cathode tube to the anode body and return to the potentiostat via the anode cable, forming a circuit and achieving electrochemical corrosion protection for the inner wall of the metal pipe or container. Furthermore, when the potentiostat is energized, electrons are conducted through the outer wall of the protected metal pipe or container to the exhaust and inlet pipes of the auxiliary anode device, enter the anode body of the auxiliary anode device, and return to the potentiostat via the anode cable, forming a circuit and achieving electrochemical corrosion protection for the outer wall of the metal pipe or container. This feature significantly improves the comprehensiveness and effectiveness of cathodic protection and extends the service life of the protected metal structure.

[0024] Compared with existing technologies, the advantages of this invention are as follows: the auxiliary anode device and cathodic protection system can simultaneously provide electrochemical corrosion protection for the inner or outer walls of metal pipes or containers, significantly improving the comprehensiveness and effectiveness of cathodic protection and extending the service life of the protected metal structure; it is applicable to various metal pipes and containers, whether large industrial equipment or small household facilities, and can be flexibly configured and used according to actual conditions. This wide applicability gives this invention greater market potential and application value. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0026] Figure 1 A structural diagram of the auxiliary anode device of this utility model is shown;

[0027] Figure 2 This invention provides a top view of the auxiliary anode device in AA cross section.

[0028] Figure 3 The diagram shows the appearance of an insulating support in the auxiliary anode device of this utility model;

[0029] Figure 4 This invention illustrates a cathode protection system that includes an auxiliary anode device.

[0030] The above figures include the following reference numerals:

[0031] 1-Auxiliary anode device, 11-Anode body, 12-Cathode round tube, 13-Insulating round tube, 131-Pipe body, 132-Upper tube cap, 133-Lower tube cap, 141-Anode cable conduit, 142-Cathode cable conduit, 15-Exhaust and water inlet pipe, 161-Anode cable, 162-Cathode cable, 17-Insulating support round tube, 18-Insulating support component, 181-Insulating bracket, 182-Support tube, 19-Through hole, 2-Potential constant, 21-Reference terminal, 22-Zero position terminal, 23-Water quality detection terminal, 3-Auxiliary cathode device, 31-Metal shell, 311-Anode terminal, 312-Solid-state reference electrode, 313-Water quality sensor, 314-Probe including corrosion test piece, 32-Connecting pipe, 4-Protected metal pipe. Detailed Implementation

[0032] To facilitate understanding of this utility model, a more comprehensive description of it will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are merely for more detailed explanation and should not be construed as limiting the utility model in any way, i.e., not limiting the scope of protection of this utility model.

[0033] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0034] All numerical designations, such as nominal diameter, length, wall thickness, and side length, including range, are approximate values. It's important to understand that while not all numerical designations are explicitly preceded by the term "approximately," this is not always the case.

[0035] Example 1

[0036] An auxiliary anode device, as shown in the attached Figure 1 As shown, it includes an anode body 11, a cathode circular tube 12, and an insulating circular tube 13;

[0037] The insulating round tube 13 includes a tube body 131, an upper tube cap 132 and a lower tube cap 133 respectively fitted on both ends of the tube body. The upper tube cap 132 is provided with an anode cable conduit 141, a cathode cable conduit 142, and an exhaust and water inlet pipe 15.

[0038] The cathode tube 12 is disposed between the inner wall of the anode body 11 and the tube body 131. The cathode tube 12 is connected to the cathode cable 162, and the cathode cable 162 passes through the cathode cable conduit 142.

[0039] One end of the anode body 11 is connected to the anode cable 161, and the anode cable 161 is threaded through the anode cable conduit 141.

[0040] Optionally, the insulating round tube 13 is a round tube made of synthetic resin, such as PE, PP, PVC, UPVC, etc. In the optional example of this utility model, the insulating round tube 13 is UPVC, which has a pressure resistance of 1.6MPa.

[0041] Optionally, the nominal diameter of the insulating round tube 13 is not less than 100mm, and the length of the insulating round tube 13 can be selected by those skilled in the art according to the specific application scenario. In the optional example of this utility model, the nominal diameter of the insulating round tube 13 is 200mm and the length is 1 meter.

[0042] Optionally, the anode body 11 is made of high-temperature resistant and corrosion-resistant aerospace titanium alloy.

[0043] Optionally, the cathode tube 12 is a round tube made of carbon steel.

[0044] Optionally, the nominal diameter of the cathode tube 12 is smaller than the nominal diameter of the insulating tube 13, and the length of the cathode tube 12 can be selected by those skilled in the art according to the specific application scenario; in the optional example of this utility model, when the nominal diameter of the insulating tube 13 is 200mm, the nominal diameter of the cathode tube 12 is 159mm, the wall thickness of the cathode tube 12 is not less than 5mm, and the length is 1 meter.

[0045] Optionally, the gap between the tube body 131 of the insulating round tube 13 and the upper cap 132 and lower cap 133 is sealed with epoxy resin.

[0046] Optionally, the cables (anode cable 161, cathode cable 162) and conduits (anode cable conduit 141, cathode cable conduit 142) and the gap between the conduits and the upper cap 132 are sealed with synthetic resin or other sealing materials.

[0047] Optionally, the cathode tube 12 has a through hole 19 at its bottom. The specific shape of the through hole 19 is not limited. In an optional example of this utility model, the hole is pre-cut at the bottom of the cathode tube 12 before installation. The through hole 19 is approximately an equilateral triangle with a side length of 5 cm.

[0048] Optionally, the inner cavity of the insulating circular tube 13 is filled with a non-metallic material. In an optional example of this utility model, the cavity between the inner wall of the anode body 11 and the cathode circular tube 12, and between the outer wall of the cathode circular tube 12 and the inner wall of the tube body 131 is filled with a non-metallic material.

[0049] Example 2

[0050] Based on the auxiliary anode device 1 shown in Embodiment 1, an exhaust water inlet pipe 15 is disposed on the edge of the upper pipe cap 132, and the number of exhaust water inlet pipes 15 is one or more.

[0051] In an optional example of this utility model, the exhaust water inlet pipe 15 is installed 7 cm off-center from the upper pipe cap 132, and the gap between the exhaust water inlet pipe 15 and the hole of the upper pipe cap 132 is cured with resin or other curing adhesive.

[0052] In an optional example of this utility model, there are two exhaust water inlet pipes 15.

[0053] Optionally, the exhaust water inlet pipe 15 is made of non-metallic material. In an optional example of this utility model, the exhaust water inlet pipe 15 is made of UPVC.

[0054] Example 3

[0055] Based on the auxiliary anode device 1 shown in Embodiment 1, as shown in the attached... Figure 1 and attached Figure 2 As shown, the anode body 11 includes multiple anode body units, and any two adjacent anode body units are separated by an insulating support member 18; the anode body is rod-shaped or strip-shaped.

[0056] Optionally, the insulating support tube 17 is made of non-metallic material. In an optional example of this utility model, the insulating support tube 17 is made of PVC tube.

[0057] Optionally, the anode body 11 includes multiple anode body units, each anode body unit including one or more anode body monomers. If the anode body unit includes multiple anode body monomers, each anode body monomer is bonded together using viscoelastic sealing tape, insulating casting adhesive or synthetic resin to form an anode body unit.

[0058] Optionally, the anode body 11 is rod-shaped or strip-shaped. In an optional example of this utility model, the anode body 11 is round rod-shaped, and the number of round rod-shaped anode bodies is 5. However, this utility model is not limited to 5. Those skilled in the art can choose according to specific circumstances.

[0059] Optionally, the insulating support component 18 is not limited. Any insulating support component 18 that serves to space any two adjacent anode body units and is connected to the cathode circular tube 12, thus providing support, is applicable to this utility model. In an optional example of this utility model, the insulating support component 18 is disposed at the upper and lower ends of the anode body 11. The insulating support component 18 includes an insulating bracket 181 and a support tube 182. The structure of the insulating bracket 181 is shown in the attached figure. Figure 3An anode rod is inserted into the central tube of the insulating support 181, and the remaining anode rods are installed in the gaps of the horizontal four-way tubes of the insulating support 181. The insulating support 181 and the anode rods are bound together with insulating cable ties. One end of the support tube 182 is inserted into the horizontal four-way tube of the insulating support 181, and the other end is connected to the cathode tube 12. Optionally, the support tube 182 is made of a high-temperature resistant non-metallic material; in an optional example of this utility model, the support tube 182 is made of UPVC.

[0060] Example 4

[0061] Based on the auxiliary anode device 1 shown in Embodiment 1, the auxiliary anode device 1 in this embodiment further includes an insulating support circular tube 17, with the insulating support members evenly distributed circumferentially between the inner wall of the tube body 131 and the outer wall of the cathode circular tube 12.

[0062] The anode cable 161 is detachably connected to the anode body 11; the cathode cable 162 is welded or bolted to the cathode tube 12.

[0063] Optionally, the anode cable 161 is connected to the anode body 11 by a stainless steel clamp; the cathode cable 162 is directly welded to the inner wall of the cathode tube 12 or iron bolts are welded to the inner wall of the cathode tube 12 for bolt connection.

[0064] It should be noted that this utility model does not limit the connection method between the anode cable 161 and the anode body 11, as well as the inner wall of the cathode tube 12. Those skilled in the art can choose according to the specific circumstances of the implementation.

[0065] Example 5

[0066] This embodiment provides an example of a cathodic protection system including the aforementioned auxiliary anode device. It should be noted that this example is merely a preferred illustration and does not limit the scope of protection of this utility model. Specifically:

[0067] A cathodic protection system, as shown in the attached Figure 4 As shown, the cathodic protection system includes at least one auxiliary anode device 1 as shown in Embodiments 1-4, as well as a potentiostat 2 and an auxiliary cathode device 3, wherein:

[0068] The positive terminal of the potentiostat 2 is connected to the anode cable 161 of the auxiliary anode device 1, and the negative terminal of the potentiostat 2 is connected to the wall of the protected metal pipe 4 or the wall of the metal container; the reference terminal 21 of the potentiostat 2 is connected to the solid reference electrode 312 of the auxiliary cathode device 3; the zero terminal 22 of the potentiostat 2 is connected to the surface of the protected metal pipe 4 or the metal container.

[0069] The cathode cable 162 of the auxiliary anode device 1 is connected to the anode terminal 311 of the auxiliary cathode device 3;

[0070] The auxiliary cathode device 3 includes a metal housing 31 and an insulated connecting pipe 32. An anode terminal 311 is provided on the metal housing 31, a solid reference electrode 312 is provided on the metal housing 31, and an insulating layer is coated on the outer wall of the metal housing 31.

[0071] One end of the connecting pipe 32 is insulated from the metal shell 31, and the other end is connected to the wall of the protected metal pipe 4 or the wall of the metal container, so that the electrolyte solution in the protected metal pipe 4 or the metal container is input into the space formed by the metal shell 31 through the connecting pipe 32.

[0072] It should be noted that the number of auxiliary anode devices 1 in this utility model is not limited and can be selected according to the specific application scenario. If there are multiple auxiliary anode devices 1, they are connected in parallel.

[0073] This invention does not limit the insulating connection method between the connecting pipe 32 of the auxiliary cathode device 3 and the metal housing 31; a flange connection can be selected. Figure 4 As shown, one end of the connecting pipe 32 is connected to a flange on the shell 31, the flanges are bolted together, and an insulating gasket is provided between the flanges.

[0074] Optionally, a switching valve is provided on the connecting pipe 32 of the auxiliary cathode device 3. By opening the switching valve, the electrolyte solution in the protected metal pipe 4 or metal container enters the auxiliary cathode device 3 of this invention, thereby improving the controllability of the device.

[0075] Optionally, a water quality sensor 313 is installed on the metal housing 31 of the auxiliary cathode device 3 to monitor the performance of the electrolyte solution in the protected metal pipe or metal container.

[0076] Optionally, the metal housing 31 of the auxiliary cathode device 3 is also provided with a probe 314 including a corrosion test piece. By setting the probe containing the corrosion test piece, the anti-corrosion effect of the cathodic protection system of this utility model can be directly characterized, which facilitates the evaluation and tracking detection of the performance of the cathodic protection system and improves the operability of the cathodic protection system.

[0077] The operation of the cathodic protection system in this embodiment includes at least the following stages:

[0078] On the one hand, after the potentiostat 2 is powered on and the protection potential value is set, electrons flow through the energized point on the outer wall of the metal pipe through the salt water on the inner wall of the pipe, and are conducted to the inner wall of the insulating metal tube on the lower side of the auxiliary cathode device 3. They are then conducted to the wiring bolt on the wall of the insulating metal tube on the lower side of the auxiliary cathode device 3 through the metal conduction of ...

[0079] On the other hand, after the potentiostat 2 is powered on, the inner wall protection potential value is set. Electrons flow through the energized point on the outer wall of the metal pipe through the damaged opening of the anti-corrosion layer on the outer wall of the pipe and enter the soil. Electrons are conducted through the soil to the exhaust and water inlet pipe 15 of the auxiliary anode device 1. Then, electrons are conducted through the non-metallic filler in the cavity of the auxiliary anode device 1 to the anode body 11, and flow back to the potentiostat 2 through the anode cable 161 to form a circuit, thereby realizing the electrochemical corrosion protection of the damaged opening of the outer wall of the pipe in contact with the soil from the energized point of the cable connection on the metal pipe to the position of the auxiliary cathode device 3.

[0080] The cathodic protection system formed above can simultaneously protect against electrochemical corrosion of the inner and outer walls of metal pipes.

[0081] It should be noted that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions; the dimensional data in this embodiment do not necessarily limit the technical solution, but merely illustrate one specific working condition. For those skilled in the art to which this invention pertains, several simple improvements and modifications can be made without departing from the concept of the present invention, and all such improvements and modifications should be considered to fall within the scope of protection of the present invention.

Claims

1. An auxiliary anode device, characterized in that, It includes an anode body (11), a cathode tube (12), and an insulating tube (13); The insulating round tube (13) includes a tube body (131), an upper tube cap (132) and a lower tube cap (133) respectively fitted on both ends of the tube body. The upper tube cap (132) is provided with an anode cable conduit (141), a cathode cable conduit (142), and an exhaust water inlet pipe (15). The cathode tube (12) is disposed between the inner wall of the anode body (11) and the tube body (131), and the cathode tube (12) is connected to the cathode cable (162), and the cathode cable (162) passes through the cathode cable conduit (142); One end of the anode body (11) is connected to an anode cable (161), and the anode cable (161) is threaded through the anode cable conduit (141).

2. The auxiliary anode device according to claim 1, characterized in that, The exhaust water inlet pipe (15) is located on the edge of the upper pipe cap (132), and the number of exhaust water inlet pipes (15) is one or more.

3. The auxiliary anode device according to claim 1, characterized in that, The anode body (11) includes a plurality of anode body units, and any two adjacent anode body units are separated by an insulating support member (18); And / or, the anode body (11) is either rod-shaped or strip-shaped.

4. The auxiliary anode device according to claim 1, characterized in that, The inner cavity of the insulating round tube (13) is filled with non-metallic material.

5. The auxiliary anode device according to claim 1, characterized in that, The bottom of the cathode tube (12) is provided with a through hole (19).

6. The auxiliary anode device according to claim 1, characterized in that, The auxiliary anode device (1) further includes an insulating support tube (17), which is circumferentially distributed between the inner wall of the tube body (131) and the outer wall of the cathode tube (12).

7. The auxiliary anode device according to claim 1, characterized in that, The anode cable (161) is detachably connected to the anode body (11); And / or, the cathode cable (162) is welded or bolted to the cathode tube (12).

8. The auxiliary anode device according to claim 1, characterized in that, The insulating round tube (13) is a round tube made of synthetic resin; and / or, the cathode round tube (12) is a round tube made of carbon steel.

9. A cathodic protection system, characterized in that, It includes at least one auxiliary anode device as described in any one of claims 1 to 7 (1).

10. The cathodic protection system according to claim 9, characterized in that, The cathodic protection system also includes a potentiostat (2) and an auxiliary cathode device (3), wherein: The positive terminal of the potentiostat (2) is connected to the anode cable (161) of the auxiliary anode device (1), and the negative terminal of the potentiostat (2) is connected to the wall of the protected metal pipe (4) or the wall of the metal container; the reference terminal (21) of the potentiostat (2) is connected to the solid reference electrode (312) of the auxiliary cathode device (3); the zero terminal (22) of the potentiostat (2) is connected to the surface of the protected metal pipe (4) or the metal container. The cathode cable (162) of the auxiliary anode device (1) is connected to the anode terminal (311) of the auxiliary cathode device (3); The auxiliary cathode device (3) includes a metal housing (31) and an insulated connecting pipe (32). An anode terminal (311) is provided on the metal housing (31). A solid reference electrode (312) is provided on the metal housing (31). An insulating layer is coated on the outer wall of the metal housing (31). One end of the connecting pipe (32) is insulated from the metal shell (31), and the other end is connected to the wall of the protected metal pipe (4) or the wall of the metal container, so that the electrolyte solution in the protected metal pipe (4) or the metal container is input into the space formed by the metal shell (31) through the connecting pipe (32).

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