Vibration Signature Analysis for Electric Arc Furnaces Free

Electric arc furnaces have been used for many years to melt scrap iron and steel but operating practice and control still rely heavily on trial‐and‐error techniques. Some of the major operating problems encountered in the melting process are excessive refractory wear, electrode breakage, and electrical power control. These problems exist primarily because the status of the melt cannot be accurately determined for each heat. Vibration signature analysis is now being developed to determine the onset and termination of different phases of the melt. A vibration sensor, attached to the side wall, sends an analog vibration signal to a Fourier analyzer which provides the power spectrum of the vibration signature. The power spec‐trums are correlated with condition of the scrap in the furnace. These signatures are different for each phase of the melt, and the features in the signatures which distinguish them from each other are utilized in an algorithm which is designed to indicate changes in the status of the melt. The electric arc furnace, its operation and problems, and the signature system are described.