Abstract: A ladle preheating system and method in which heat input rate to the ladle is calculated and monitored throughout the preheating period, calculating the moving average slope representing change over time of the rate of change of heat input, correcting the moving average slope for unavoidable variations in the measurements of the heat input rate, calculating the change of the moving average slope over time (the approximate second derivative), and signaling to an operator the readiness of the ladle based upon this second derivative's falling below a preset criteria indicating a fully preheated ladle.

Abstract: A method is provided for extending the life of a refractory lining of a blast furnace hearth. The refractory hearth has temperature probes embedded in the floor and walls thereof. The method includes periodically measuring temperatures indicated by the probes and determining the campaign maximum and current average temperature readings to locate two solidification isotherm representing the wear line of the refractory and the inner surface of the protective metal layer. The thickness of the protective layer is determined from the distance between the solidification isotherms representing the refractory wear line and the inner surface of the metal skull. From this determination sufficient thickness of the protective layer is maintained during actual operation of the furnace.

Abstract: A method is provided for determining the thickness of a protective layer of solidified metal skull formed on the refractory hearth of a blast furnace. The refractory hearth has temperature probes embedded in the floor and walls thereof. The method includes periodically measuring temperatures indicated by the probes and determining the campaign maximum and current average temperature readings to locate two solidification isotherms representing the wear line of the refractory and the inner surface of the protective metal layer. The thickness of the protective layer is determined from the distance between the solidification isotherms representing the refractory wear line and the inner surface of the metal skull.

Abstract: A method of determining the conditions of heat transfer at the interface of the refractory and a metal shell of the furnace by calculating the interface temperature from thermoprobes in the refractory and then from a thermoprobe in the metal shell and the temperature of cooling water applied to the shell, and comparing these interface temperatures to determine whether a gap has formed between the refractory and shell and whether cooling of the shell is sufficient.

Abstract: A method is provided for on-line monitoring of the wear of a refractory lining of a blast furnace and for extending the life of said lining. The method includes determining the wear line of the lining from signals of temperature probes embedded at spaced locations across the thickness of the refractory using a one dimensional heat transfer model to locate a first approximation of a solidification isotherm of hot metal in the furnace, using the one dimensional heat transfer approximation as an initial boundary in a moving boundary calculation of a two dimensional heat transfer model and iterating the two dimensional model to find a final location of the isotherm by minimizing the difference between the measured and predicted temperatures of the thermoprobes.