Method of and apparatus for measuring level and characteristics of a slag layer overlying a metallurgical metal

A method of measuring the level of slag in a vessel and a physical parameter of the slag, comprising the steps of:

• (a) feeding jets of a gas into said vessel through a wall thereof at two locations spaced above a metallurgical charge in said vessel and disposed one above the other on said wall, at least three jets being provided, two of said jets being positioned at the same level along said wall, the third jet being disposed above the level of the two jets;
• (b) initially establishing flows through said jets to provide equal back pressure therefor;
• (c) detecting the back pressures of said jets while maintaining said flows to monitor the hydrostatic head of slag in said vessel as it rises above the lower jet;
• and
• (d) determining the position of the slag level and said parameter by monitoring deviations of the detected back pressures from the original back pressures using said two jets positioned at the same level, one of said two jets providing a reference indicating the reliability of said determination when the back pressure therein equals the back pressure in the other jet positioned at the same level.

A device for determining the level of a layer of slag overlying a metallurgical melt in a top-blown melt-containing metallurgical vessel having a vertical wall and for determining a physical parameter of said slag, said device comprising:

• a pair of pressure inlet tubes opening laterally through said wall into said vessel at vertically spaced locations;
• means for feeding a gas to said tubes;
• means for adjusting the rate of flow of said inert gas to establish substantially identical back pressures at said tubes in the absence of a slag layer in said vessel, said means including valves in said tubes responsive to the back pressures therein;
• means connected to said tubes for measuring said back pressures;
• and
• means responsive to the measured back pressures and deviations thereof from original back pressure values for indicating the level of slag in said vessel and a physical parameter of said slag upon slag in said vessel rising above the lower pressure inlet, in accordance with the relationship that the back pressures are proportional to the product of the density of the slag and the height thereof above the lower inlet tube.

A device for determining the level of a layer of slag overlying a metallurgical melt in a vessel having a vertical wall and for determining a physical parameter of said slag, said device comprising:

• a pair of tubes opening through said wall into said vessel to form pressure inlets at vertically spaced locations, each of said pressure inlets comprising a ceramic body having a throughgoing passage received in a lining of said wall, a metal tube lining said passage of said refractory body, a further tube received in said metal tube and opening into the interior of said vessel, and a flexible tube extending through said wall and connected to said further tube, said body being formed with a chamber turned away from the interior of said vessel and said flexible tube having a U-band received in said chamber
• means for feeding a gas to said flexible tubes;
• means for adjusting the rate of flow of said inert gas to establish substantially identical back pressures at said tubes in the absence of a slag layer in said vessel, said means including valves in said tubes responsive to the back pressures therein;
• means connected to said tubes for measuring said back pressures;
• and
• means responsive to the measured back pressures and deviations thereof from original back pressure values for indicating the level of slag in said vessel and a physical parameter of said slag upon slag in said vessel rising above the lower pressure inlet, in accordance with the relationship that the back pressures are proportional to the product of the density of the slag and the height thereof above to lower inlet tube.