What is an impressed current anode?

What is an impressed current anode?

Impressed current anodes refer to a kind of anode of cathodic protection systems. These anodes are powered by the DC current from an external source. A proper selection of impressed current anodes would include the consideration of the environment that surrounds a buried or submerged structure to control corrosion.

What materials can anodes be made of?

The three most active materials used in sacrificial anodes are zinc, aluminum and magnesium. They have different properties and uses. The first property to consider is their electrical potential. All metals generate a negative voltage (as compared to a reference electrode) when immersed in water.

What properties are essential for an anode metal to be used in an impressed current cathodic protection system?

The anode must have high anode efficiency (i.e., the current produced by the metal dissolution must be readily available for cathodic protection). Magnesium and zinc are the most often used galvanic anodes for the cathodic protection of pipelines.

Which is used as an anode in impressed current cathodic protection?

Elements such as Zinc, Aluminium, Magnesium or their alloys are used as a sacrificial anode to protect the parent element like Iron or Steel which forms the cathode.

Which anode is used in impressed voltage method?

(a) Impressed Current System An external positive voltage is applied to an inert anode (silicon, cast iron, titanium) which is placed in concrete.

What kind of material is an impressed current anode made of?

The anodes employed are generally made of graphite, cast iron, titanium alloys, silicon iron and platinum-niobium clad metals. Impressed current anodes are found in many sizes and shapes such as wires, rods, tubes, plates and sticks. Impressed current anodes are less likely to be attacked by corrosion due to their inert nature.

What kind of anodes are used in cathodic protection?

A cathodic protection system has two types of anodes: a galvanic or sacrificial anode and an impressed current anode. Impressed current anodes are inert anodes used in impressed current protection in cathodic protection systems. These anodes are powered by the DC current from an external source.

How to design impressed current cathodic protection for steel?

Design an impressed current cathodic protection for steel immersed in freshwater by calculating the current required, selecting an anode material, number of anodes, circuit resistance and power source selection. 3.

What’s the difference between anode and sacrificial anode?

A sacrificial anode is a highly active metal that can save the less active metal surfaces from corrosion. It can be a metal or a metal alloy. Another name for this type of anodes is galvanic anode. These anodes supply cathodic protection.