Zinc anode and its applications:
Zinc anode is commonly used in sea water or brackish water. In some cases, it is also used for structures buried in the ground and to eliminate the induced effects of the high voltage network. Zinc anodes are manufactured according to MIL-A-18001K, BS3436 grade Zn1, DNV B 401, NOROSOK M-501 standards. The capacity of zinc anode is 780 ampere hours/kg with 85% efficiency and the open circuit voltage of these anodes is -1.05V. Zinc anode is produced in two forms, cast and extruded. The core in both production methods is made of steel belt with galvanized or cadmium coating. In order to connect to the structure under protection, the mentioned belt must have high physical resistance. Zinc anode is divided into two categories in terms of application and chemical composition:
A) Standard zinc alloy designed for use in fresh water and soil.
b) Seawater Alloy, which is suitable for use in seawater.
Zinc anode is used in electrolytes with a specific resistance of less than 1000 Ohm.cm, in water and mud environment. The said anodes have a fixed current capacity, which are suitable for the structure under protection in the early years of cathodic protection and require a small current.
Chemical analysis of zinc anode according to standards (ASTM G97, B 273, IPS-M-TP-750/1)
Design requirements:
In water environments with temperatures higher than 60 degrees Celsius, due to the reversal of polarity between iron and zinc, zinc anode cannot be used to protect the steel hulls from corrosion.
According to the NACE-RP0387 standard, the insert used in zinc anodes must be made of galvanized steel.
Depending on the type of anode and its application, zinc anodes are connected to the structure using various methods such as welding, bolts and cable connections. All kinds of zinc anodes with different shapes, sizes and weights can be produced for different uses.
Anode on a screw with one hole to protect heat exchangers Anode on a screw with two holes to protect heat exchangers
Zinc anodes in various rectangular and drop-shaped shapes with welded connection to the structure; For the protection of the hull of the ship and marine applications
Zinc anode for cathodic protection of ship’s balance tanks
