Graphite electrode for DC arc furnace

The graphite electrode DC arc furnace is a new type of electric furnace steelmaking equipment that developed and matured in the early 1980s.

The early DC arc furnaces were modified based on the original AC arc furnaces, some using three graphite electrodes and some using two graphite electrodes. However, after the mid-1980s, most newly designed DC arc furnaces only used one graphite electrode. Compared with AC arc furnaces using three graphite electrodes of the same power, the total surface area of the oxidized electrodes at high temperatures was greatly reduced. Similarly, DC arc furnaces operating at ultra-high power can reduce the consumption of graphite electrodes per ton of steel by about 50%. When the DC arc furnace current passes through the electrodes, there is no skin effect or proximity effect, and the current distribution is uniform across the electrode cross-section. Moreover, the stability of the DC arc is good, and the mechanical vibration during operation is small. The noise of the electric furnace is also low. The diameter of graphite electrodes used in DC arc furnaces is also calculated based on the furnace capacity and the allowable current density of the electrodes. For ultra-high power electric furnaces with the same input power, a DC furnace using one graphite electrode has a larger electrode diameter. For example, an AC arc furnace with a capacity of 150t uses an electrode with a diameter of 600mm, while a DC arc furnace with the same capacity uses an electrode with a diameter of 700-750mm. The quality requirements for graphite electrodes in DC arc furnaces are higher than those used in AC arc furnaces.