Our titanium anode for cathodic protection has been completed and shipped today
Customer use: for cathodic protection
Coating: The outer wall of the titanium tube is coated with ruthenium and iridium
Coating thickness: 8-10um
Of course, in addition to the tube, it can also provide a variety of shapes, generally including MMO titanium anode tube, titanium anode tape, titanium anode rod, titanium anode wire, titanium conductive tape, titanium anode mesh, titanium anode plate
Titanium anode tube specifications: diameter 20, 25, 50, 80mm, length is designed and produced according to user requirements, generally 1000mm, 1500mm, 2000mm
Titanium anode belt specifications: 0.635mm*6.35mm*150m (150 meters or 152 meters per roll) Titanium conductive belt: 0.9*12.7*150 meters
Titanium anode rod: diameter 1mm-50mm and length according to user requirements design and production, titanium anode mesh: design and production according to user specifications
At present, the most widely used shape for cathodic protection exported by our company is tubular, the size is 25*1*1000mm.
Principle of Cathodic Protection:
The corroded metal is a multi-electrode coupling system. When the metal material is in contact with the electrolyte solution, a corrosion battery is often formed due to the electrochemical inhomogeneity of the metal surface. This kind of corrosion battery can be simplified as a two-electrode primary battery. Therefore, cathodic protection can be achieved by the following two methods.
1. Using external current to make the entire surface of the protected metal structure become a cathode, it is called external current cathodic protection.
When applying external current cathodic protection to metal equipment, the metal wire can be connected to the negative pole of an external power supply, and the other auxiliary anode can be connected to the positive pole of the power supply. At this time, after the current passing through the auxiliary anode flows through the electrolyte solution, it is mainly concentrated on the cathode part of the metal. Cathodic polarization of the metal occurs. This current flows back to the power supply through the cathode, thereby reducing the total potential of the metal. If the added protection current is large enough, the original anode on the protected structure will no longer dissolve, and complete protection will be obtained at this time.
2. Connecting a metal or alloy with a more negative potential to the metal equipment that needs to be protected is called sacrificial anode protection.
According to the principle of cathodic protection, any metal structure needs cathodic protection, and the following conditions should be specified:
(1) The environmental medium must be conductive. Because these media will form part of the cathodic protection system, so that the protection current can flow through the conductive media to form a complete electrical circuit. Cathodic protection can be implemented in media such as soil, seawater, and acid-base salt solutions, but not in gaseous media. The protection effect of the gas-liquid interface and the alternating wet and dry parts is not good. In strong acid farmer solutions, cathodic protection is generally not suitable because of the large current consumption of protection.
(2) Metal materials should be easy to be polarized cathodically in the medium in which they are located, otherwise cathodic protection methods are not suitable due to the large current consumption. Cathodic protection should not be used for metals in a passive state in the medium.
(3) The geometric shape of the metal structure to be protected should not be too complicated, otherwise the protection current will be unevenly distributed and partial protection will be insufficient or over-protected.
At present, cathodic protection methods are mainly used in the following media:
A: In fresh water and sea water, prevent corrosion of ships, docks, platforms, gates and cooling equipment.
B: In alkali and salt solutions, prevent corrosion of storage tanks, evaporation tanks, caustic soda pots, etc.
C: Prevent corrosion of pipelines and cables in soil and sea mud.
Cathodic protection is an effective method to control corrosion. It can eliminate battery and galvanic corrosion and limit local corrosion. At present, it has been widely used in many anti-corrosion structures such as underground cables, oil transportation, gas pipelines, parking lots, bridges, coastal structures, drilling platforms, ships, chemical industries, and power generation equipment.
MMO has been increasingly used in cathodic protection. It has the advantages of high current density, acid resistance, and long life. It is used in fresh water, soil, seawater, and concrete. Cathodic protection is to add cathodic polarization to the metal to be protected for the purpose of reducing activity and preventing metal corrosion. Generally, two schemes can be used to achieve:
1. Impressed current cathodic protection method
The impressed current cathodic protection uses an impressed current to make the entire surface of the protected metal structure the cathode. When applying external current cathodic protection to metal equipment, connect the metal wire to the negative pole of an external power source, and connect the other auxiliary anode to the positive pole of the power source. At this time, after the current through the auxiliary anode flows through the electrolyte solution, it is mainly concentrated on the cathodic protection of the metal, so that the metal is cathodicly polarized, and the current flows back to the power source through the cathode, thereby reducing the total potential of the metal. If the applied protection current is large enough, the original anode on the protected structure will no longer dissolve. At this time, only the cathodic reduction reaction occurs on the metal surface, and the addition is to achieve complete protection. Cathode materials are continuously developed and improved for different use conditions.
Because the metal oxide coating anode uses titanium as the substrate and the surface is coated with a platinum group metal oxide with high catalytic activity, it has good electrical conductivity and small surface output resistance, and it is not corroded by the medium itself. And easy processing and other advantages. It can be adapted to different environments, such as sea water, fresh water, soil and other media.
2. Sacrificial anode protection method
Sacrificial anode protection is to connect a metal with a more negative potential to the metal to be protected as the anode, which forms a large battery in the electrolyte with the metal to be protected. Dia Niu flows into the metal device from the anode through the electrolyte, and polarizes the cathode of the metal device to obtain corresponding protection.
Application: cathodic protection of underground metal structures, oil pipelines, cathodic protection of ships, cathodic protection of seawater steel structures
1. The cathodic protection method of sacrificial anode, also known as the sacrificial anode protection method, is a method to prevent metal corrosion, that is, the metal with strong reducibility is used as the protective electrode, and the metal to be protected is connected to form a galvanic battery. The metal will be consumed as a negative electrode in an oxidation reaction, and the protected metal can be used as a positive electrode to avoid corrosion.
2. The metal with strong reducibility is used as the protective electrode, which is connected with the protected metal to form a galvanic battery. The metal with strong reducibility will be used as the negative electrode to undergo oxidation reaction and consumed, and the protected metal can be used as the positive electrode to avoid corrosion. Because this method sacrifices the anode, which is the negative electrode of the primary battery, and protects the cathode, which is the positive electrode of the primary battery, it is called the sacrificial anode protection method.
3. Advantages: no need for external power supply; little maintenance; small current output causes little or no stray current interference; easy to install; in most cases, it is easy to add anodes; to provide uniform current distribution.
4. Disadvantages: lower driving voltage and current; more anodes are required for inferior coating structures; it may be ineffective in high-resistance soil environments; due to lower current efficiency, the cost per ampere current is higher than Impressed current cathodic protection; replacement of spent anodes is difficult or expensive.