System for optically analyzing a molten metal bath

Abstract

A system for optically analyzing a molten metal bath wherein a high velocity gas stream is passed from a lance to the bath and is maintained coherent by a flame envelope to provide a clear sight pathway through the gas stream for sighting the molten metal bath longitudinally through the gas stream from a remote or spaced sighting point.

1 . A method for optically analyzing a molten metal bath comprising: 
 (A) forming a coherent gas stream by passing a gas stream out from a lance and surrounding the gas stream with a flame envelope;    (B) passing the coherent gas stream to a molten metal bath;    (C) sighting longitudinally through the coherent gas stream to view the molten metal bath and obtain optical data therefrom; and    (D) passing the optical data to an analyzer.    
     
     
         2 . The method of  claim 1  wherein the sighting through the coherent gas stream comprises using a light source transmitting light through the coherent gas stream.  
     
     
         3 . The method of  claim 2  wherein the light source is a laser.  
     
     
         4 . The method of  claim 1  wherein the flame envelope extends from the lance to the molten metal bath.  
     
     
         5 . The method of  claim 1  wherein the coherent gas stream has a supersonic velocity when it contacts the molten metal bath.  
     
     
         6 . The method of  claim 1  wherein the coherent gas stream comprises oxygen.  
     
     
         7 . The method of  claim 1  wherein the optical data enables the determination of the composition of the molten metal of the molten metal bath.  
     
     
         8 . The method of  claim 1  wherein the optical data enables the determination of the temperature of the molten metal of the molten metal bath.  
     
     
         9 . The method of  claim 1  wherein the molten metal bath comprises unmelted scrap and the optical data enables the determination of melted versus unmelted scrap in the molten metal bath.  
     
     
         10 . The method of  claim 1  wherein the molten metal bath comprises molten metal and a slag layer above the molten metal, and wherein the coherent gas stream passes through the slag layer to the molten metal.  
     
     
         11 . Apparatus for optically analyzing a molten metal bath comprising: 
 (A) a molten metal furnace containing a molten metal bath;    (B) a lance having an ejection end for passing a coherent gas stream to the molten metal bath;    (C) a sight glass mounted on the lance aligned so as to view the molten metal bath longitudinally though the coherent gas stream to obtain optical data; and    (D) an analyzer and means for passing the optical data to the analyzer.    
     
     
         12 . The apparatus of  claim 11  further comprising a light source for generating light for passage through the coherent gas stream.  
     
     
         13 . The apparatus of  claim 12  wherein the light source is a laser.  
     
     
         14 . The apparatus of  claim 11  wherein the lance is positioned so as to provide the coherent gas stream to the molten metal bath in a direction perpendicular to the surface of the molten metal-bath.  
     
     
         15 . The apparatus of  claim 11  wherein the sight glass is positioned on the lance on the end opposite the ejection end of the lance.  
     
     
         16 . The apparatus of  claim 11  wherein the means for passing optical data to the analyzer comprises a light guide assembly comprising optical fiber passing from the sight glass to the analyzer.  
     
     
         17 . The apparatus of  claim 11  wherein the means for passing optical data to the analyzer comprises a light guide assembly comprising a system of lenses and mirrors.  
     
     
         18 . The apparatus of  claim 11  wherein the analyzer comprises an optical spectrometer.  
     
     
         19 . The apparatus of  claim 11  wherein the analyzer comprises a pyrometer.