DC electric arc furnace is a new type of electric furnace steelmaking equipment developed in the early 1980s. The initial DC electric arc furnace was transformed from the original AC electric arc furnace. How to Choose Graphite Electrode for DC Electric Arc Furnace? Some used 3 graphite electrodes and some used 2 graphite electrodes.
After the mid-1980s, most of the newly designed DC electric arc furnaces only used one graphite electrode. Compared with AC electric arc furnaces with three graphite electrodes of the same power, the total surface area of the electrode that was oxidized at a high temperature was greatly reduced. The DC arc furnace operating at the same high power can reduce the (hp) graphite electrode consumption per ton of steel by about 50%. DC arc furnace current does not produce skin effect and proximity effect when passing through the electrode. The current distribution is uniform on the electrode cross section, and the stability of the DC arc is good. The mechanical vibration is small during operation, and the noise of the electric furnace is also low.
The diameter of the graphite electrode used in the DC electric arc furnace is also calculated based on the capacity of the electric furnace and the allowable current density of the electrode. 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. DC arc furnaces have higher quality requirements for graphite electrodes than graphite electrodes used in AC arc furnaces.