IEC has in its portfolio the Iron-Silicon-Chromium Anodes that are extremely important items for the composition of the cathodic protection system. The anodes are manufactured by Anotec Industries Ltd, a Canadian company that we represent exclusively in Brazil.
Iron-Silicon-Chromium Anodes for impressed current cathodic protection are used to provide electrical current through soil and natural waters to protect structures by mitigating corrosion. During the process, the anodes are slowly consumed.
The anodes used in the impressed current system differ fundamentally from the galvanic anodes because they are inert, presenting a very low consumption and having a longer life.
The main features of these anodes are:
– Permissible current density
The permissible current density is a characteristic of the type of material used in manufacturing. The utilization of a current density above the maximum recommended can cause a sharp and irregular utilization of the anode. In certain cases, it may give rise to the appearance of insulating products on the surface.
Each type of anode has a known consumption rate when operating within the maximum current density limit. The consumption rate of a certain type of anode needs to be considered for the calculation of its life. In general, the ground bed is designed for a minimum life span of 15 to 20 years.
The electrical contact resistance between the anode and the electrolyte is a function of the anode dimensions and the electrolyte resistivity. Therefore, once the installation location is defined, the resistance of each anode will depend on its dimensions. Length or diameter increase in the anode will result in a reduction of the strength, however, the influence of the length is much greater than the diameter. The total resistance of the anode bed, in applications in soils from medium to high resistivity, is, in general, the factor that defines the number of anodes to be used.
The iron / silicon / chromium anodes (Fe-Si-Cr) are manufactured by Anotec Indutries Ltd. in circular bars, by casting, with a silicon content of 16% and a chromium content of not less than 4%. And are recommended for soils, sea water, seabed and freshwater.