A system for estimating both thickness and wear state of refractory material (1) of a metallurgical furnace (12), including at least on processor including a database of simulated frequency domain data named simulated spectra representing simulated shock waves reflected in simulated refractory materials of known state and thickness, each simulated spectrum being correlated with both known state and thickness data of the considered simulated refractory material, wherein the at least one processor is configured to record a reflected shock wave as a time domain signal, and to convert it into frequency domain data named experimental spectrum, and are further configured to compare the experimental spectrum with at least a plurality of simulated spectra from the database, to determine the best fitting simulated spectrum with the experimental spectrum and to estimate thickness and state of the refractory material (1) of the furnace (12) using known state and thickness data correlated with the best fitting simulated spectrum.

A gas purging plug for blowing gas into a metallurgical vessel, having the form of an elongated body made of a first refractory material, contains a final visual wear indicator in the form of an elongated core extending from an inlet end to a distance, along a central longitudinal axis, less than the length of the elongated body. The final visual wear indicator is made of a second refractory material that differs in visual appearance from the first refractory material between 800 and 1500 degrees C. The plug also contains an intermediate visual wear indicator extending from the inlet end to a point between the end of the final visual wear indicator and the opposite end of the elongated body. The intermediate visual wear indicator is made of a third refractory material that differs in visual appearance from the first and second refractory materials between 800 and 1500 degrees C.

Method for determining the state of a fire-resistant lining of a vessel containing molten metal in particular in which maintenance data, production data, and wall thicknesses at least at locations with the highest degree of wear are measured or ascertained together with additional process parameters of at least one identical/similar vessel after the vessel has been used. The data is collected and stored in a data structure. A calculating model is generated from at least some of the measured or ascertained data or parameters, and the data or parameters are evaluated using the calculating model using calculations and subsequent analyses. Thus, related or integral ascertaining processes and subsequent analyses can be carried out, on the basis of which optimizations relating to both the vessel lining as well as the complete process of the molten metal in the vessel are achieved.

A measurement system is provided for predicting a future status of a refractory lining that is lined over an inner surface of an outer wall of a metallurgical vessel and exposed to a heat during which the refractory lining is exposed to molten metal. The system includes one or more laser scanners and a processor. The laser scanners are configured to conduct a plurality of laser scans of the refractory lining when the metallurgical vessel is empty. At least one of the laser scanners is configured to laser scan the refractory lining prior to the heat to collect data related to pre-heat structural conditions of the refractory lining. At least one of the laser scanners is configured to laser scan the refractory lining after the heat to collect data related to post-heat structural conditions of the refractory lining. The processor is configured to predict the future status of the lining.

Method for determining the state of a fire-resistant lining of a vessel containing molten metal in particular in which maintenance data, production data, and wall thicknesses at least at locations with the highest degree of wear are measured or ascertained together with additional process parameters of at least one identical/similar vessel after the vessel has been used. The data is collected and stored in a data structure. A calculating model is generated from at least some of the measured or ascertained data or parameters, and the data or parameters are evaluated using the calculating model using calculations and subsequent analyses. Thus, related or integral ascertaining processes and subsequent analyses can be carried out, on the basis of which optimizations relating to both the vessel lining as well as the complete process of the molten metal in the vessel are achieved.

An apparatus (2) for determining thickness of refractory material (4) lining a metal vessel (6) is disclosed. The apparatus includes a radiation source (16) for emitting radiation through a metal wall of the vessel and into the refractory material, wherein some of the radiation is scattered by the refractory material, and a radiation detector (20) for detecting radiation scattered by the refractory material through the wall of the vessel. A converter provides an output signal dependent on the quantity of radiation scattered by the refractory material through the wall of the vessel and detected by the radiation detector.

A system for estimating both thickness and wear state of refractory material of a metallurgical furnace, including at least one processor including a database of simulated frequency domain data named simulated spectra representing simulated shock waves reflected in simulated refractory materials of known state and thickness, each simulated spectrum being correlated with both known state and thickness data of the considered simulated refractory material, wherein the at least one processor is configured to record a reflected shock wave as a time domain signal, and to convert it into frequency domain data named experimental spectrum, and are further configured to compare the experimental spectrum with at least a plurality of simulated spectra from the database, to determine the best fitting simulated spectrum with the experimental spectrum and to estimate thickness and state of the refractory material of the furnace using known state and thickness data correlated with the best fitting simulated spectrum.

An apparatus (2) for determining thickness of refractory material (4) lining a metal vessel (6) is disclosed. The apparatus includes a radiation source (16) for emitting radiation through a metal wall of the vessel and into the refractory material, wherein some of the radiation is scattered by the refractory material, and a radiation detector (20) for detecting radiation scattered by the refractory material through the wall of the vessel. A converter provides an output signal dependent on the quantity of radiation scattered by the refractory material through the wall of the vessel and detected by the radiation detector.