Submerged entry nozzle with dynamic stabilization

Abstract

The present invention relates to a pour tube for casting molten metal. The pour tube is adapted to reduce turbulence and mold disturbances, thereby producing a more stable, uniform outflow. The pour tube includes an exit port with at least one tongue to provide at least two slots on either side of the tongue. The slots generate counter-rotating flows, which result in a more diffusive and more homogeneous outflow. Advantageously, such an outflow can reduce detrimental asymmetry and alumina clogging in the pour tube.

1 - 12 . (canceled)  
   
   
       13 . A pour tube for use in casting a stream of molten metal from an upstream position to a downstream position, the pour tube comprising an inner surface defining a bore and an outer surface having at least one exit port defined at least partially by an edge and fluidly connected to the bore, wherein the exit port includes at least one tongue extending from an edge, whereby at least two slots are created in the exit port.  
   
   
       14 . The pour tube of  claim 13 , wherein the exit port includes a downstream edge and the tongue extends upstream from the downstream edge.  
   
   
       15 . The pour tube of  claim 13 , wherein the exit port includes an upstream edge and the tongue extends downstream from the upstream edge.  
   
   
       16 . The pour tube of  claim 13 , wherein the exit port includes an upper tongue extending downstream from an upstream edge and a lower tongue extending upstream from a downstream edge.  
   
   
       17 . The pour tube of  claim 13  wherein the pour tube includes a longitudinal axis between the upstream and downstream positions.  
   
   
       18 . The pour tube of  claim 17 , wherein at least one tongue includes an extended surface, and the extended surface defines a tongue plane that intersects the longitudinal axis at an angle from −45 to +45 degrees.  
   
   
       19 . The pour tube of  claim 17 , wherein at least one edge includes an edge surface defining an edge plane that intersects the longitudinal axis at an angle from −45 to +45 degrees.  
   
   
       20 . The pour tube of  claim 17 , wherein the exit port defines an exit plane substantially parallel to the longitudinal axis.  
   
   
       21 . The pour tube of  claim 13 , wherein the bore comprises a plurality of fluidly connected sections.  
   
   
       22 . The pour tube of  claim 21 , wherein a discontinuity separates each section.  
   
   
       23 . The pour tube of  claim 21 , wherein the sections include at least one frusto-conical section.  
   
   
       24 . A method of casting a stream of molten metal using a pour tube as described in any one of claims  13 - 23 , comprising: 
 a) flowing a stream of metal through the bore;    b) directing the stream towards the exit port; and    c) producing symmetric counter-rotating currents in the stream as the stream passes through the exit port.