Apparatus for treating molten metal having a sealed treatment zone

Abstract

An apparatus for treating molten metal includes a treatment vessel for holding molten metal and a removable cover or hood for the vessel. Sealing means are provided between the cover and the vessel to provide a gas tight treatment zone. The sealing means include mating peripheral flanges on the vessel and cover, with the cover flange having three spaced annular sealing strips for contacting the vessel flange. These sealing strips include a first outer annular strip formed of an elastomeric material to give an air tight seal between the cover and vessel and a second middle annular strip formed of a deformable fibrous refractory material to provide a thermal barrier between the interior of the vessel and the outer annular strip. A third inner annular strip is a rigid metal strip upon which the cover is supported on the vessel with the cover flange at a fixed distance above the vessel flange and the outer sealing strip and middle sealing strip compressed therebetween to a controlled degree.

1 . An apparatus for in-line treatment of a molten metal, comprising: 
 a treatment vessel for holding said molten metal, a removable cover for the treatment vessel and sealing means between the cover and the vessel to provide a gas tight treatment zone, said sealing means comprising mating peripheral flanges on said vessel and said cover, having between said mating flanges three spaced annular sealing strips adapted to contact said flat mating face, said three annular sealing strips including an outer annular strip formed of an elastomeric material adapted to provide an air-tight seal between the cover flange and vessel flange, a middle annular strip formed of a deformable refractory material adapted to provide a thermal barrier between the cover flange and the vessel flange and an inner metal annular strip providing a mechanical protection for said middle annular strip.    
     
     
         2 . The apparatus according to  claim 1  wherein the said vessel has an inlet and outlet for connecting said vessel to a metallurgical trough, and wherein a baffle is placed at said inlet and outlets to act as an air-lock to prevent air entry or gas escape.  
     
     
         3 . The apparatus according to  claim 1  wherein the three annular strips are mounted on the face of one of the said mating flanges.  
     
     
         4 . The apparatus according to  claim 1  wherein the inner metal sealing strip has a square or rectangular cross-section.  
     
     
         5 . The apparatus according to  claim 1  wherein the middle sealing strip comprises a refractory rope, felt or paper.  
     
     
         6 . The apparatus according to  claim 5  wherein the middle sealing strip comprises a ceramic fiber rope wrapped in refractory fabric.  
     
     
         7 . The apparatus according to  claim 1  wherein the middle sealing strip comprises a metal mesh core wrapped in a refractory fabric.  
     
     
         8 . The apparatus according to  claim 4  wherein the outer annular strip has a square or rectangular cross-section.  
     
     
         9 . The apparatus according to  claim 1  wherein the outer annular strip has an oval or round cross-section.  
     
     
         10 . The apparatus according to  claim 1  wherein the three annular sealing strips are connected to the flange of the cover.  
     
     
         11 . The apparatus according to  claim 10  wherein the cover rests on the treatment vessel with the inner metal sealing strip resting on the vessel flange and the middle and outer sealing strips slightly compressed between the cover and vessel flanges.  
     
     
         12 . The apparatus according to  claim 11  wherein the vessel flange has one or more curved ridges on its surface and one or more of the sealing strips contact the curved ridges.  
     
     
         13 . The apparatus according to  claim 12  wherein the one or more curved ridges contact the outermost sealing strip.  
     
     
         14 . The apparatus according to  claim 1  wherein the treatment vessel is an apparatus for de-gassing molten metal.  
     
     
         15 . The apparatus according to  claim 14  which includes gas injection rotors extending downward from the cover and into the treatment zone.  
     
     
         16 . The apparatus according to  claim 1  wherein the cover rests on the treatment vessel under its own weight.  
     
     
         17 . The apparatus according to  claim 1  wherein the cover is fixed to the treatment vessel by way of quick release clamping means.  
     
     
         18 . The apparatus according to  claim 1  which includes ventilator means for removing gases from the treatment zone.