Classification of Electric Arc Furnaces
Classified by Electrode Melting Type
Non-consumable Electrode Electric Arc FurnaceIt adopts tungsten, graphite or other materials as electrodes. The electrodes have little or no consumption during smelting.
Consumable Electrode Electric Arc FurnaceThe electrode is made of the metal to be smelted. The metal electrode melts and consumes itself continuously during operation.
Classified by Arc Length Control Mode
Constant Arc Voltage Automatic Control EAFIt compares the actual voltage between two electrodes with the set voltage. The deviation signal is amplified to drive the lifting and lowering of the consumable electrode, so as to maintain a constant arc length.
Constant Arc Length Automatic Control EAFIt maintains roughly fixed arc length by stabilizing arc voltage.
Droplet Pulse Automatic Control EAFIt automatically stabilizes arc length based on the correlation between arc length and pulse frequency & duration generated during metal droplet formation and dripping.
Classified by Operation Mode
Batch Operation EAFOne complete smelting process counts as one production cycle.
Continuous Operation EAFTwo mainstream structures:① Rotary furnace body type;② Dual-furnace shared DC power supply type: once one furnace finishes smelting, the power supply switches to the other furnace to start the next heat immediately.
Classified by Furnace Body Structure
Fixed Electric Arc Furnace
Rotary Electric Arc Furnace
Common Types of Electric Arc Furnaces
Three-Phase Electric Arc Furnace
Powered by three-phase alternating current, it normally uses carbon or graphite electrodes. Arcs form between electrodes and furnace charge to directly heat raw materials. Arc length is adjusted via electrode lifting system.For better smelting quality, large EAFs are equipped with electromagnetic stirrers at the furnace bottom to circulate molten metal directionally. Furnaces above 50 tons are often fitted with tilting rotary mechanisms, enabling lateral rotation for uniform heating and tilting for molten steel tapping. Three-phase EAFs are widely applied in steelmaking.
Consumable Arc Furnace
Its electrode is composed of the steel raw material to be melted. The electrode descends continuously as steel material melts. Molten steel droplets fall into a water-cooled copper cylindrical crucible and solidify into ingots. This furnace is mainly used for smelting alloy steel.Consumable arc furnaces for reactive and refractory metals (titanium, zirconium, tungsten, molybdenum, tantalum, niobium etc.) usually operate under vacuum, known as vacuum consumable arc furnaces.
Single-Phase Electric Arc Furnace
Supplied with single-phase alternating current, it heats furnace charge indirectly via electric arcs. It is mostly used for melting copper and copper alloys.
Resistance-Arc Furnace
Its structure is similar to steelmaking EAFs. During operation, electrode tips are embedded in furnace charge to strike arcs. Heat comes not only from arcs between electrodes and charge, but also from resistance heat generated when current flows through raw materials.This furnace is primarily used for ore smelting, also named submerged arc furnace.