The term sacrificial anode can be explained quite well with cathodic corrosion protection (CCP), on the basis of galvanic corrosion. Galvanic corrosion occurs when at least two metals are present and one metal(anode) corrodes in relation to another(cathode). Corrosion can often be attributed to the poor compatibility of selected materials, where one metal (e.g. magnesium) corrodes towards another metal (e.g. steel storage tank wall) and an anodic-cathodic cell is formed.
For this reaction to occur, different metals must be electrically connected to each other (e.g. by water in the hot water storage tank/elector lyte). The metal with the lower voltage (anode - magnesium anode) dissolves in the electrolyte. The dissolving magnesium thereby migrates via the water (electrolyte) to the metal with the higher voltage (cathode - enamelled storage tank wall).
You are now asking yourself, what does all this have to do with my hot water tank?Every enamelled hot water tank has defects due to the production process. The magnesium particles of the protective anode (anode) migrate via the water (electrolyte) to the imperfections in the enamelling (cathode) in order to protect the cylinder from corrosion (protective layer). The magnesium anode OPFERS (degrades) and is therefore also called a sacrificial anode. If you have any questions about "What is a sacrificial anode", please do not hesitate to contact us.