Systems and methods for controlling the electrode position in an arc furnace

A system for controlling the position of an electrode in an arc furnace, the system comprising:

• an arc furnace comprising a molten bath and slag disposed over the molten bath, wherein the slag contacts the molten bath at an interface;
• an electrode comprising a lower tip, wherein the electrode is configured to deliver current by disposing the lower tip of the electrode below the upper surface of the slag, the current being configured to form an electric arc between the upper surface of the slag and the interface;
• a sensor configured to detect the current;
• a filtering device in communication with the sensor and configured to output only the harmonic frequencies which fall within a predefined filter range;
• and
• a digital processor in communication with the filtering device configured to determine the position of the lower tip of the electrode relative to the upper surface of the slag based on harmonic frequencies associated with the current, wherein the lower tip position relative to the upper surface of the slag correlates to the harmonic frequencies.

A method for controlling position of an electrode lower tip in an arc furnace, wherein the arc furnace comprises a molten bath and slag disposed over the molten bath, the method comprising:

• positioning the electrode tip below the upper surface of the slag;
• forming an electric arc by delivering current via the electrode to the upper surface of the slag;
• determining the position of the electrode lower tip relative to the upper surface of the slag by measuring harmonic frequencies associated with the current, wherein the position of the electrode lower tip relative to the upper surface of the slag correlates to the harmonic frequencies;
• and
• repositioning the lower tip of the electrode when the lower tip of the electrode is disposed above the upper surface of the slag or when a portion of the electrode in addition to the lower tip is submerged below the upper surface of the slag.