What is a impressed current cathodic protection system and how does it work?

For cathodic protection in large structures, the use of cathodic protection system of sacrificial anodes may not be appropriate. The number of sacrificial anodes required to provide sufficient current to protect the structure against corrosion may be excessive or impractical. To control this, an external energy source is used to help conduct electrochemical reactions. are Impressed current cathodic protection system is a type of system that is usually used in cases where high flow requirements required to protect against corrosion or control needs to be increased. In impressed current cathode protection (ICCP) systems, the current required for protection is supplied from an external source of electrical energy supplied by a DC regulated power supply called a transformer. ICCP systems for corrosion protection are ideal for many structures, such as underground pipelines, storage tanks, large ships, and offshore and offshore structures.

How does a impressed current cathodic protection system work?

The impressed current cathodic protection system consists of one or more reference electrodes and several ICCP anodes, all connected to the same power supply. The reference electrodes adjust the required output current unit on the anodes by measuring the electrical protection potential of the environment in which the structure is located. Adjusted current prevents the corrosion process from occurring. In this method, unlike the sacrificial anode method, where the anodes were negative, the anodes are more positive than the structure. The positive pole of the power supply is connected to the anode and the negative pole is connected to the structure. Therefore, the positive ions inside the electrolyte return from the anode to the metal in question. Depending on the electrolyte in which the structure is located, the applied voltage must be such that it can withstand sufficient current intensity for all parts of the device that is cathodically protected. Provide. A properly installed, commissioned, and serviced ICCP system can last for 25 years or more.

impressed current anodes

The cathodic protection system consists of two types of anodes: the sacrificial anode and the impressed current anode.

A impressed current anode uses an external power source known as a “rectifier” to create a high potential difference between the protected surface and the anode. The anodes used are generally made of graphite, cast iron, titanium alloy and silicon iron. Today, the most common type of impressed current anodes are MMO anodes, which are found in various sizes and shapes such as wires, rods, tubes, plates and strips. The choice of the type of impressed current anodes to protect the structure from corrosion depends on the environment in which the structure is located. For example, ribbon MMO anodes are used to protect the bottom of tanks.

Impressed current anodes have advantages over sacrificial anodes, including:

• They have higher flow efficiencies.
• Less anodes are needed to protect the structure.
• Reduce the initial cost.