Auxiliary cathode device and cathode protection system comprising same

Abstract

The utility model provides an auxiliary cathode device and a cathode protection system comprising the same. The auxiliary cathode device comprises a metal shell and an insulated communicating pipe, an anode terminal is arranged on the metal shell and is used for connecting a cathode cable end of the auxiliary anode device; one end of the communicating pipe is communicated with the metal shell in an insulating manner, and the other end of the communicating pipe is communicated with the pipe wall of the protected metal pipeline or the wall of the metal container, so that an electrolyte solution in the metal pipeline or the metal container is input into a space formed by the metal shell through the communicating pipe; therefore, current input from the cathode cable of the auxiliary anode is transmitted to the inner surface of the protected metal pipeline or metal container through the anode terminal and the electrolyte solution in the metal shell, and protection electrons are provided for electrochemical corrosion of the contact surface of metal on the inner surface of the pipeline or container and the electrolyte solution. The cathode protection system comprising the auxiliary cathode device can simultaneously perform forced current cathode protection on the inner wall and the outer wall of a metal pipeline or a metal container.

Description

Technical Field

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

[0002] Cathodic protection is a type of electrochemical protection technology. Its principle involves applying an external current to the surface of a corroded metal structure, making the protected structure the cathode. This inhibits electron migration that causes corrosion, thus preventing or reducing corrosion. Currently, cathodic protection technology is widely used for the protection of pipelines, ship hulls, underground storage tanks, offshore platforms, heat exchangers, and other equipment or devices.

[0003] Cathodic protection technology is divided into sacrificial anode cathodic protection and forced current cathodic protection. Among them, sacrificial anode cathodic protection involves connecting a metal with a more negative potential to the metal being protected and placing them in the same electrolyte, so that electrons from the sacrificial anode metal are transferred to the metal being protected, thus placing the entire metal being protected at a relatively negative and uniform potential. This method is simple and easy to implement, but it is easily limited by the service life of the anode and soil conditions.

[0004] Forced current cathodic protection involves applying an external DC power supply and an auxiliary anode to supply a large number of electrons to the metal, creating an electron surplus state across the entire metal surface. This results in all points on the metal surface reaching the same negative potential, making the protected metal structure's potential lower than the surrounding environment, thus providing protection. This method is characterized by stable operation and is mainly used to protect large metal structures or those located in soils with high resistivity, such as long-distance buried pipelines and large metal tank complexes. However, it is worth noting that existing forced current cathodic protection technology can only provide corrosion protection for the outer walls of equipment; the internal corrosion protection of metal pipelines or metal containers remains a significant technical challenge. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model discloses an auxiliary cathode device and a cathodic protection system including the device, in order to solve the technical problem that existing technologies cannot simultaneously achieve cathodic protection of the inner and outer walls of metal pipes or metal containers by applying strong current.

[0006] To achieve the above technical objectives, this utility model proposes an auxiliary cathode device, which includes a metal shell and an insulated connecting pipe, wherein:

[0007] An anode terminal is provided on the metal housing, which is used to connect to the cathode cable terminal of the auxiliary anode device; a solid reference electrode is provided on the metal housing, which is used to connect to the reference terminal of the potentiostat; the outer wall of the metal housing is coated with an insulating layer.

[0008] 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 metal pipe or the metal container is introduced into the space formed by the metal shell through the connecting pipe.

[0009] When using the auxiliary cathode device of this invention for cathodic protection, the electrolyte solution inside the wall of the protected metal pipe or metal container is introduced into the metal shell through the connecting pipe. This allows the current input from the cathode cable of the auxiliary anode to be transmitted through the anode terminal and the electrolyte solution inside the metal shell to the inner surface of the protected metal pipe or metal container. This provides protective electrons for electrochemical corrosion occurring at the interface between the metal surface of the pipe or container and the electrolyte solution, thereby inhibiting electrochemical corrosion of the inner wall of the metal pipe or metal container. Combining this auxiliary cathode device with a traditional cathodic protection system allows for simultaneous high-current cathodic protection of both the inner and outer walls of the protected metal pipe or metal container.

[0010] It should be noted that the electrolyte solution described in this utility model refers to a solution containing substances that can dissociate into ions in water, thereby making the aqueous solution conductive. Under certain working conditions, it can also be water directly.

[0011] In another aspect, this utility model proposes a cathodic protection system comprising at least one of the aforementioned auxiliary cathode devices. This cathodic protection system, which includes the aforementioned auxiliary cathode devices, further combines the strong current cathodic protection provided by the conventional cathodic protection system for the outer wall of the protected pipe or container. It can simultaneously provide strong current cathodic protection for both the inner and outer walls of the metal pipe or container, providing comprehensive corrosion protection and thus effectively extending the service life of the metal pipe or container.

[0012] Compared with existing technologies, the beneficial effects of this invention are as follows: The auxiliary cathode device of this invention introduces the electrolyte solution from the protected metal pipe or container into the metal housing connected to the cathode cable of the auxiliary anode device through an insulated connecting pipe. This allows the current output from the auxiliary anode device to be transmitted through the electrolyte solution in the metal housing to the electrolyte solution in the protected metal pipe or container during operation, inhibiting electrochemical corrosion between the inner surface of the metal pipe or container and the electrolyte ions. The cathodic protection system incorporating this auxiliary cathode device can achieve electrochemical cathodic protection of the inner wall of the metal pipe or container while simultaneously providing cathodic protection by applying a strong current to the outer wall of the metal pipe or container, as is the traditional method. This protection system is simple, practical, and has significant application value. Attached Figure Description

[0013] 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:

[0014] Figure 1 This diagram shows a structural illustration of the auxiliary cathode device of this invention.

[0015] Figure 2 This diagram illustrates a structural diagram of the cathodic protection system of this invention.

[0016] The above figures include the following reference numerals:

[0017] 1-Auxiliary cathode device, 11-Metal housing, 111-Anode terminal, 112-Solid-state reference electrode, 113-Water quality sensor, 114-Probe including corrosion test piece, 115-First bolt, 116-Second bolt, 117-Third bolt, 12-Connecting pipe, 121-Switch valve, 122-Flange, 123-Insulating gasket, 124-Fourth bolt, 125-Insulating sleeve, 2-Protected metal pipe, 3-Potentialistor, 31-Reference terminal, 32-Zero position terminal, 33-Water quality detection terminal, 4-Auxiliary anode device. Detailed Implementation

[0018] To facilitate understanding of this utility model, a more comprehensive description of the present utility model 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 present utility model in any way, i.e., not limiting the scope of protection of the present utility model. Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which this utility model pertains.

[0019] Example 1

[0020] An auxiliary cathode device 1 includes a metal housing 11 and an insulated connecting pipe 12, such as... Figure 1 As shown, where:

[0021] An anode terminal 111 is provided on the metal housing 11, which is used to connect to the cathode cable end of the auxiliary anode device; a solid reference electrode 112 is provided on the metal housing 11, which is used to connect to the reference terminal 31 of the potentiostat 3; the outer wall of the metal housing 11 is coated with an insulating layer.

[0022] One end of the connecting pipe 12 is insulated from the metal shell 11 and connected to the wall of the protected metal pipe or the wall of the metal container, so that the electrolyte solution in the metal pipe or the metal container is introduced into the space formed by the metal shell 11 through the connecting pipe 12.

[0023] It should be noted that the specific shape of the metal shell 11 is not limited in this utility model. It can be cylindrical, rectangular, rhomboid, spherical, irregular or other shapes, with cylindrical being preferred. Those skilled in the art can choose according to their needs, and this does not limit the scope of protection of this utility model.

[0024] It should be noted that this invention does not limit the connection method between the solid-state reference electrode 112 and the metal housing 11; a fixed connection or a detachable connection can be selected. In one optional example of this invention, the solid-state reference electrode 112 is detachably connected to the metal housing 11 to facilitate the inspection and replacement of the solid-state reference electrode 112. Furthermore, this invention does not limit the detachable connection method between the solid-state reference electrode 112 and the metal housing 11, for example… Figure 1 An example is shown in which the solid reference electrode 112 is detachably connected to the metal housing 11 by a first bolt 115.

[0025] It should be noted that this invention does not limit the relative position of the anode terminal 111 or the solid reference electrode 112 on the metal housing 11; those skilled in the art can set it according to actual needs. In an optional example of this invention, the solid reference electrode 112 is disposed at the bottom of the metal housing 11 to reduce measurement errors. Distributing it at the bottom also makes it easier to access and maintain, facilitating inspection and replacement. In an optional example of this invention, such as... Figure 1 As shown, the anode terminal 111 is located on the side wall of the metal housing 11.

[0026] It should be noted that the outer wall of the metal pipe or metal container protected by the auxiliary cathode device of this utility model is coated with an insulating layer.

[0027] Example 2

[0028] Based on the auxiliary cathode device 1 shown in Embodiment 1, a water quality sensor 113 is provided on the metal housing 11 of the auxiliary cathode device 1 shown in this embodiment. Thus, a suitable sensor can be set according to actual needs to detect one or more performance parameters of the electrolyte solution, such as temperature, pH, conductivity, turbidity, etc., to monitor the performance of the electrolyte solution in the protected metal pipe 2 or metal container.

[0029] Furthermore, multiple water quality sensors 113 can be installed on the metal casing 11 of the auxiliary cathode device 1 to monitor electrolyte parameters at different locations, and can also monitor different electrolyte solution performance parameters at different locations. Those skilled in the art can make the settings according to actual needs.

[0030] Furthermore, the water quality sensor 113 is either fixedly connected to or detachably connected to the metal housing 11. A detachable connection is preferable to facilitate the maintenance and functional adjustment of the water quality sensor 113. It should be noted that this invention does not limit the specific method of detachable connection between the water quality sensor 113 and the metal housing 11; bolted connections, snap-fit ​​connections, or other optional methods are possible, such as... Figure 1 An example is shown where the water quality sensor 113 is detachably connected to the metal housing 11 by a second bolt 116.

[0031] Example 3

[0032] Based on the auxiliary cathode device 1 shown in Embodiment 1, the metal housing 11 of the auxiliary cathode device 1 shown in this embodiment is provided with a probe 114 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 on the inner wall of metal pipes or metal containers 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.

[0033] Furthermore, this invention does not limit the connection method between the probe 114, including the corrosion test piece, and the metal housing 11; a fixed connection or a detachable connection can be selected. In an optional example of this invention, the probe 114, including the corrosion test piece, is detachably connected to the metal housing 11, such as... Figure 1 The probe 114, which includes a corrosion test piece, is detachably connected to the metal housing 11 by a third bolt 117 for easy maintenance and replacement.

[0034] Example 4

[0035] Based on the auxiliary cathode device 1 shown in Embodiment 1, the material of the insulating connecting tube 12 is not limited in this invention. The connecting tube 12 can be selected as a polyvinyl chloride insulating tube, a polyethylene insulating tube, a cross-linked polyethylene insulating tube, a glass fiber insulating tube, a metal insulating tube, a ceramic insulating tube, a polytetrafluoroethylene insulating tube, etc.

[0036] In this embodiment, the connecting pipe 12 is a metal pipe with an insulating layer on its outer wall, thereby improving the mechanical properties of the connecting pipe 12 and facilitating its use in various working conditions. It should be noted that when the connecting pipe 12 is a metal pipe with an insulating layer on its outer wall, the auxiliary cathode device 1 of this utility model can also achieve the effect of preventing corrosion of the inner metal wall of the connecting pipe 12 and extending its service life.

[0037] Example 5

[0038] Based on the auxiliary cathode device 1 shown in Embodiment 1, a switching valve 121 is provided on the connecting pipe 12 in this utility model. By opening the switching valve 121, the electrolyte solution in the protected metal pipe 2 or metal container enters the auxiliary cathode device 1 of this utility model, thereby improving the controllability of the device.

[0039] Example 6

[0040] Based on the auxiliary cathode device 1 shown in Embodiment 1, this invention does not limit the insulating connection method between the connecting pipe 12 and the metal housing 11; a flange connection can be selected. Figure 1 As shown, one end of the connecting pipe 12 is connected to a flange 122, which is then connected to the housing. The two flanges 122 are fixed by a fourth bolt 124, and an insulating gasket 123 is placed between the flanges 122, thereby achieving insulated communication between the connecting pipe 12 and the metal housing 11. Optionally, an insulating sleeve 125 is provided between the flange 122 and the fourth bolt 124 to further enhance the insulated communication between the connecting pipe 12 and the metal housing 11.

[0041] Example 7

[0042] Based on the auxiliary cathode device 1 shown in Embodiment 1, the present invention does not limit the material of the metal shell 11 and the protected metal pipe or metal container. Those skilled in the art can choose the same or different metal materials as needed, without limiting the scope of protection of the present invention.

[0043] In this embodiment, the material of the metal shell 11 can be the same as that of the protected metal pipe or metal container, thereby avoiding the formation of a potential difference and the occurrence of electrochemical corrosion under certain working conditions due to the difference in material between the metal shell 11 and the protected metal pipe 2 or the metal shell 11.

[0044] Example 8

[0045] Based on the auxiliary cathode device 1 shown in Embodiment 1, the outer wall of the metal housing 11 in this embodiment is coated with an insulating and anti-corrosion layer to achieve multi-effect protection of the outer wall of the auxiliary cathode device 1, including insulation and anti-corrosion.

[0046] And / or, the outer wall of the metal shell 11 is covered with thermal insulation material, which helps to improve the operational stability of the auxiliary cathode device 1 of this utility model, making it suitable for more extreme environmental conditions and expanding its application range.

[0047] Example 9

[0048] This embodiment presents an example of an optional cathodic protection system. It should be noted that this embodiment is merely a preferred illustration and does not limit the scope of protection of this utility model. Specifically:

[0049] A cathodic protection system includes at least one auxiliary cathode device 1 as shown in Embodiments 1-8, a potentiostat 3, and an auxiliary anode device, wherein: the positive output terminal of the potentiostat 3 is connected to the anode cable terminal of the auxiliary anode device, and the negative output terminal of the potentiostat 3 is connected to the wall of the protected metal pipe or the wall of the protected metal container; the reference terminal 31 of the potentiostat 3 is connected to the solid-state reference electrode 112 of the auxiliary cathode device 1; the zero-position terminal 32 of the potentiostat 3 is connected to the surface of the protected metal pipe or metal container; when the auxiliary cathode device 1 is equipped with a water quality sensor 113, the water quality detection terminal 33 of the potentiostat 3 is connected to the water quality sensor 113; the cathode cable terminal of the auxiliary anode device is connected to the anode terminal 111 of the auxiliary cathode device 1. Figure 2 A schematic diagram showing the connection between the cathodic protection system of this utility model and the protected metal pipe 2 is shown.

[0050] The operation of the cathodic protection system in this embodiment includes at least the following stages:

[0051] On one hand, after the potentiostat 3 is powered on and its operating parameters are set, the current from the positive terminal of the potentiostat 3 is input to the auxiliary anode device via a cable, and further transmitted to the metal housing 11 of the auxiliary cathode device 1 via the cathode cable of the auxiliary anode device. Since the surface of the metal housing 11 has an insulating layer, and the metal housing 11 is insulated from the connecting pipe 12, the current can only be transmitted to the inner surface of the protected metal pipe or metal container through the conductive electrolyte solution inside the metal housing 11. When the current flows through the inner surface of the metal pipe or metal container, it provides protective electrons for electrochemical corrosion occurring when the inner wall of the pipe comes into contact with the electrolyte solution, thereby inhibiting electrochemical corrosion of the inner wall of the pipe or container. Finally, the current flowing through the protected metal pipe 2 or metal container returns to the negative terminal of the potentiostat 3 via a cable, completing the cathodic protection of the inner wall of the protected metal pipe 2 or metal container with a strong current. The data detected by the zero-position terminal 32 and the reference terminal 31 of the potentiostat 3 provide a reference for setting the operating parameters of the potentiostat 3.

[0052] On the other hand, the auxiliary anode device is located in the soil. The current input to the auxiliary anode device is transmitted to the protected metal pipe or metal container through soil electrons, so that the outer wall of the pipe or container is cathodically polarized to prevent corrosion. Finally, the current flows back to the negative terminal of the output of the potentiostat 3 via a cable, thus completing the cathodic protection of the outer wall of the protected metal pipe 2 or metal container by applying current.

[0053] Therefore, the cathodic protection system including the auxiliary cathode device 1 of this utility model can simultaneously provide corrosion protection for the inner and outer walls of the protected metal pipe 2 container.

[0054] It should be noted that the cathodic protection system of this utility model can be configured with multiple auxiliary cathodic protection devices at different locations of the metal pipe 2 or metal container according to the changes in the specifications of the protected metal pipe 2 or metal container, so as to achieve comprehensive cathodic protection of the inner and outer walls of the pipe or container by applying strong current.

[0055] Furthermore, this invention does not limit the number of potentiostats 3 in the cathodic protection system. It can be selected to set at least 2 units, with 1 of them as a backup, thereby ensuring the stable operation of the cathodic protection system in practical applications.

[0056] Furthermore, the potentiostat 3 is equipped with a remote control module, thereby enabling the remote transmission of protection parameters of the protected object and realizing remote transmission and remote control functions.

[0057] 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 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 cathode device, characterized in that, It includes a metal housing (11) and an insulated connecting pipe (12), wherein: an anode terminal (111) is provided on the metal housing (11), the anode terminal (111) is used to connect to the cathode cable end of the auxiliary anode device; a solid reference electrode (112) is provided on the metal housing (11), the solid reference electrode (112) is used to connect to the reference terminal (31) of the potentiostat (3); the outer wall of the metal housing (11) is coated with an insulating layer; One end of the connecting pipe (12) is insulated from the metal shell (11), and the other end is connected to the wall of the protected metal pipe (2) or the wall of the metal container, so that the electrolyte solution in the metal pipe or metal container is input into the space formed by the metal shell (11) through the connecting pipe (12).

2. The auxiliary cathode device according to claim 1, characterized in that, A water quality sensor (113) is installed on the metal housing (11).

3. The auxiliary cathode device according to claim 1, characterized in that, The metal housing (11) is provided with a probe (114) including a corrosion test piece.

4. The auxiliary cathode device according to claim 1, characterized in that, The connecting pipe (12) is a metal pipe with an insulating layer coated on its outer wall.

5. The auxiliary cathode device according to claim 1, characterized in that, A switch valve (121) is installed on the connecting pipe (12).

6. The auxiliary cathode device according to claim 1, characterized in that, The metal housing (11) is flanged to the connecting pipe (12).

7. The auxiliary cathode device according to claim 1, characterized in that, The metal shell (11) is made of the same material as the protected metal pipe (2) or metal container.

8. The auxiliary cathode device according to claim 1, characterized in that, The outer wall of the metal casing (11) is coated with an insulating and anti-corrosion layer.

9. The auxiliary cathode device according to claim 1, characterized in that, The outer wall of the metal shell (11) is covered with thermal insulation material.

10. A cathodic protection system, characterized in that, It includes at least one auxiliary cathode device as described in any one of claims 1-9.

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