There are two main types of DC arc furnaces:
DC Electric Arc Furnace (DC EAF) and Vacuum arc remelting (VAR) furnaces.
DC EAF usually are used in steel production, where special requirements are raised (metal quality, AC network limitations, ecological reasons) while VAR are used most frequently in high value applications. Essentially it is an additional processing step to improve the quality of metal. Nickel, titanium and specialty steels are materials most often processed with VAR.
DC Electric Arc Furnace (DC EAF)
Vacuum arc remelting (VAR)
Both DC EAF and VAR have a number of similar characteristics: “falling” load characteristics (over the running of the process, the load voltage decreases, while the current increases – in DC EAF), strict requirements for limiting of the of pulse current zone and the speed of the control system.
For DC EAF, it is reasonable to use rectifier units with a variable structure of the power part, when the entire unit is divided into single rectifier units, which, depending on the mode, are connected in series, in series-in parallel, or in parallel, providing the required technological parameters.
Rectifiers from ETS Engineering have the following features:
- DC current up to 130kA, DC voltage up to 120V;
- solution with dry-type transformer in one shelter IP54 with rectifier alloys to install a rectifier inside a building, near the furnace;
- shelter size and layout could be optimized to suit existing plant layout, including busbar arrangement, the version with a sectional container allows you to install the equipment in areas of the shop with difficult access;
- in the branch of each thyristor, a conductivity and reverse current sensor is installed, signals from which are sent to the protection system;
- optical high-precision DC meter is used;
- fully digital control system with optical links to thyristors, accuracy 0,5%;
- advanced diagnostics system;
- easy integration with furnace control system.
Full set of factory tests of all equipment and software significantly reduces the cost of putting equipment into operation. All documentation provided includes comprehensive instructions for operational and maintenance personnel, including electrical diagrams of all components.
