The short network of an electric arc furnace (EAF) refers to the section of the power transmission system that runs from the bottom of the electrodes to the secondary output terminals of the furnace transformer. As a critical path for high-current transmission, the short network plays a vital role in ensuring efficient power delivery and the safe, stable operation of the furnace.
What Components Are Included in the EAF Short Network?
The short network typically includes the following main components:
Graphite Electrodes
Serving as the terminal part of the short network, graphite electrodes are widely used for their excellent electrical conductivity and high-temperature resistance. They do not melt or soften below 3800°C but slowly oxidize and peel, making them ideal for electric arc furnace applications.
Copper Conductors on Electrode Arms
Copper pipes or bars mounted on the electrode arms provide efficient electrical conduction and are often water-cooled to manage temperature rise during operation.
Water-Cooled Flexible Cables
Located between the furnace shell and the transformer room, these cables are designed for flexible, high-current transmission in high-temperature environments.
Copper Busbars or Tubes
These connect the flexible cables to the transformer terminals, ensuring safe and stable power transfer.
What Are the Design Requirements for the EAF Short Network?
To achieve efficient and reliable power transmission, the short network must meet several key design criteria:
Keep the Circuit as Short as Possible
The name “short network” reflects this fundamental principle: shorter paths reduce energy loss and voltage drop.
Minimize the Skin Effect
To make full use of the conductor cross-section, rectangular busbars with a large width-to-thickness ratio and thin profiles are preferred, which helps reduce the uneven current distribution caused by the skin effect.
Optimize Conductor Arrangement
Opposite current-carrying conductors should be placed as close as possible. A triangular layout (delta connection) is often used to cancel out magnetic fields between phases and reduce inductive losses.
Ensure Phase Balance
Maintaining a balanced three-phase current flow is essential for improving energy efficiency and extending equipment lifespan.
Use Non-Magnetic Support Materials
Busbar supports should be made from non-magnetic materials to avoid additional eddy currents and unwanted heating in strong magnetic fields.
Use High-Conductivity Materials
Copper is the primary material used in short network components due to its excellent conductivity. Some parts may also use aluminum alloys or copper-steel composites to balance conductivity, mechanical strength, and cost.
Reinforce Electrode Arms
The conductive arms are usually made from copper-steel composites or aluminum alloys, combining good electrical performance with structural integrity and reduced weight.
