Direct Current (DC) Arc Furnace

Applicable only in large furnace sizes, in a direct current (DC) furnace system only a single electrode is used, and the bottom of the vessel serves as the anode. This arc furnace achieves an energy savings of approximately 5% in terms of power unit consumption in comparison with the older designs of 3-phase AC arc furnaces. In addition, it also has other features, including higher melting efficiency and extended hearth life. The power consumption of DC furnaces is around 1.8-2.2 GJ/t-steel. Electrode consumption is about half that with conventional furnaces (corresponding to 1-2 kg/t-steel) (US EPA, 2010. p35). 

Development Status Products
Commercial
EAF Steel

Direct Current (DC) Arc FurnaceCosts & Benefits

Parent Process: Electric Arc Furnace
Energy Savings Potential

Net energy savings over older AC furnaces are estimated to be 0.32GJ/t-steel. Compared to new AC furnaces, the savings are limited to 0.036-0.072 GJ/t-steel (US EPA, 2010. p.35). 

CO2 Emission Reduction Potential

Emissions reduction potential of the technology is 52.9 Kg CO2/t-steel (US EPA, 2010. p.11).

Costs

The additional investment costs over that of an AC furnace are approximately $6.1/t capacity. The payback time is estimated as 0.7 years (US EPA, 2010. p.35).

Direct Current (DC) Arc FurnaceSchematic

Direct Current (DC) Arc Furnace Publications

Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry

The U.S. Environmental Protection Agency’s (EPA) energy guide, Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry, discusses energy efficiency practices and technologies that can be implemented in iron and steel manufacturing plants. This guide provides current real world examples of iron and steel plants saving energy and reducing cost and carbon dioxide emissions.

Page Number: 

95

Global Warming Countermeasures: Japanese Technologies for Energy Savings / GHG Emissions Reduction

This revised 2008 version of the publication from New Energy and Industrial Technology Development of Japan includes information on innovative Japanese technologies for energy efficiency and for the reduction of COemissions.  

Page Number: 

82