A molten material liquid level detection method that can detect a liquid level of molten material from a residual amount of the molten material with high accuracy and a method for operating a vertical furnace by using the detection method. The molten material liquid level detection method detects a liquid level of molten material remaining in a bottom portion of a vertical furnace after end of discharge of a molten material. The molten material liquid level detection method includes calculating a void fraction of the solid-filled structure, and detecting a liquid level of the molten material after the end of the discharge by using the calculated void fraction and a residual amount of the molten material after the end of the discharge.

A molten material liquid level detection method that can detect a liquid level of molten material from a residual amount of the molten material with high accuracy and a method for operating a vertical furnace by using the detection method. The molten material liquid level detection method detects a liquid level of molten material remaining in a bottom portion of a vertical furnace after end of discharge of a molten material. The molten material liquid level detection method includes calculating a void fraction of the solid-filled structure, and detecting a liquid level of the molten material after the end of the discharge by using the calculated void fraction and a residual amount of the molten material after the end of the discharge.

The present disclosure relates to a method of detecting crack propagation in a wall of a metallurgical furnace by a detection unit. The detection unit is configured to extract one or more dominant frequency parameters from the corresponding reflected stress signal, and analysing, a phase from each dominant frequency parameters. The analysing of the phase comprises determines, one or more coefficients for each dominant frequency parameters. The detection unit then identifies, a dominant phase based on the corresponding one or more coefficients and selects a frequency relevant to a thickness parameter based on the dominant phase. The crack propagation in the wall of the metallurgical furnace is then detected based on the frequency relevant to the thickness parameter at each of the one or more locations. The present disclosure provides an accurate method for determining condition of refractory lining by elimination unwanted noise signals.

The present disclosure relates to a method of detecting crack propagation in a wall of a metallurgical furnace by a detection unit. The detection unit is configured to extract one or more dominant frequency parameters from the corresponding reflected stress signal, and analysing, a phase from each dominant frequency parameters. The analysing of the phase comprises determines, one or more coefficients for each dominant frequency parameters. The detection unit then identifies, a dominant phase based on the corresponding one or more coefficients and selects a frequency relevant to a thickness parameter based on the dominant phase. The crack propagation in the wall of the metallurgical furnace is then detected based on the frequency relevant to the thickness parameter at each of the one or more locations. The present disclosure provides an accurate method for determining condition of refractory lining by elimination unwanted noise signals.

A surface detection apparatus for a blast furnace is provided. An antenna is fixed to a side of a container attached to an opening portion of the blast furnace and having a bottom surface opened in correspondence to the opening portion. A reflection plate is disposed in the container immediately above the opening portion so as to face the opening portion and the antenna. A tilt angle varying mechanism and a rotation mechanism for the reflection plate are configured as a double pipe structure and are provided at an anti-antenna side of the reflection plate.

The present invention relates to damage detection systems for refractory linings for molten metal vessels, comprising an electrically conductive grid disposed underneath the surface of the refractory lining closest to a molten metal when in use, one or more electrically conductive electrodes disposed in contact with the molten metal when in use and an electrical power source, wherein the electrically conductive metallic grid and the one or more electrically conductive electrodes are electrically connected to each other, such as to form an open electrical circuit powered by the said electrical power source, and a detected closure of the said electrical circuit during normal use of the molten metal vessel indicates that the said refractory lining is damaged, or the presence of a molten metal during normal operation of the vessel closes the said electrical circuit in case the refractory lining is damaged. The present invention relates to a method for detecting damage in a refractory lining during use, and the use of a damage detection system according to the invention.

The present invention relates to damage detection systems for refractory linings for molten metal vessels, comprising an electrically conductive grid disposed underneath the surface of the refractory lining closest to a molten metal when in use, one or more electrically conductive electrodes disposed in contact with the molten metal when in use and an electrical power source, wherein the electrically conductive metallic grid and the one or more electrically conductive electrodes are electrically connected to each other, such as to form an open electrical circuit powered by the said electrical power source, and a detected closure of the said electrical circuit during normal use of the molten metal vessel indicates that the said refractory lining is damaged, or the presence of a molten metal during normal operation of the vessel closes the said electrical circuit in case the refractory lining is damaged. The present invention relates to a method for detecting damage in a refractory lining during use, and the use of a damage detection system according to the invention.

An integrated refractory management system includes: a cable module, at least a portion of which is inserted into a refractory; a measurement module, disposed outside the refractory, for measuring a current signal flowing through the cable module; an integrated management module for determining the state of the refractory on the basis of the current signal measured by the measurement module, displaying the state of the refractory, and generating management information on the refractory; and a local terminal for receiving the management information from the integrated management module.

An integrated refractory management system includes: a cable module, at least a portion of which is inserted into a refractory; a measurement module, disposed outside the refractory, for measuring a current signal flowing through the cable module; an integrated management module for determining the state of the refractory on the basis of the current signal measured by the measurement module, displaying the state of the refractory, and generating management information on the refractory; and a local terminal for receiving the management information from the integrated management module.

A method and apparatus of reducing thermal shock in one or more radiant tubes of a pyrolysis furnace is provided. The apparatus is a furnace comprising a blower and blower bypass conduit providing separate fluid communication paths for flue gas from the convection section to a natural draft flue gas stack. The method comprises the steps of: redirecting at least a portion of the flue gas through the blower bypass conduit when a blower shut-off event is indicated as well as reducing the firing rate of the furnace.