Reprint: Advantages of DC Electric Arc Furnace

 

Advantages of DC Electric Arc Furnace

DC Electric Arc Furnace is an arc furnace that uses DC power to supply electricity.

Like AC Arc Furnace, it also uses the arc generated between the electrode and the charge (or molten pool) to generate heat to achieve the purpose of smelting.

The structural difference between DC Arc Furnace and AC Arc Furnace is:

Three electrodes that can move up and down are installed on the top of the three-phase AC Arc Furnace, while the DC Furnace only has one electrode that can move up and down on the top of the furnace, and the other electrode is fixed at the bottom of the furnace.

The DC Electric Arc Furnace needs DC power supply, so it has one more set of rectifier equipment to convert three-phase AC power into DC power than the three-phase AC Arc Furnace.

Compared with the traditional AC arc furnace, the main advantages of the DC arc furnace are:

(1) The arc is stable and concentrated, the molten pool is well stirred, the temperature distribution in the furnace is uniform, and the production efficiency can be increased by 10%;

(2) The current and voltage fluctuations are small, the impact on the power grid is reduced, the three-phase power supply is balanced, the power factor is high, and more than 5% of electricity can be saved;

(3) The electrode loss is small, and the electrode consumption per ton of steel is 50% less than that of the AC arc furnace.

Due to the limitation of the DC power supply capacity, the development of the DC arc furnace is slow. With the development of thyristor technology, the manufacturing technology of high-power DC power supply equipment has gradually matured. In the late 1970s, the DC arc furnace began to receive attention from the metallurgical industry.

The power supply system of the DC electric arc furnace is different from that of the AC arc furnace. It requires a rectifier to convert AC into DC.

There is only one electrode on the top of the DC electric arc furnace, which is the negative electrode, and the bottom electrode of the furnace is the positive electrode. Generally, a copper plate is placed on the steel plate at the bottom of the furnace as the bottom electrode to facilitate conductivity. Three layers of magnesia carbon bricks are laid on the copper plate, and then refractory materials are tied on top.

Among various bottom electrodes, the most widely used one is the water-cooled steel rod bottom electrode.

The article is reproduced from Sanrui Electric Furnace: Advantages of DC Electric Arc Furnace

E-mail: alice@srfurnace.com  / Tel: +86 15686041999 (Alice)

E-mail: anna@srfurnace.com  / Whatsapp: +86 159 2955 5868 (Anna)

Website: www.srfurnace.com / www.srmeltingfurnace.com / 

Xi'an Sanrui Electric Furnace