Continuous casting sealing method

Abstract

A casting furnace for manufacturing a metal casting comprises an interior chamber and a secondary chamber through which the metal casting passes from the interior chamber into external atmosphere. A seal along the secondary chamber surrounds and seals against the metal casting to separate the interior chamber from the external atmosphere in a manner which allows for an extended period of continuous casting. A force producing mechanism may force the seal against the metal casting. Multiple seals may be used sequentially to increase the duration of the sealing capability and the continuous casting process. Inert gas sensors may detect loss of inert gas from the interior chamber.

1 . A method comprising the steps of:
 forming an ingot in an interior chamber defined by a sidewall;   directing the ingot from the interior chamber into a secondary chamber;   providing a first backing member which is movable relative to the sidewall and in contact with a compressible first seal; and   applying a first force to the first backing member to force the first seal against the ingot along the secondary chamber.   
     
     
         2 . The method of  claim 1  wherein the step of applying comprises applying the first force hydraulically or pneumatically. 
     
     
         3 . The method of  claim 1  wherein the step of applying comprises applying the first force with a force producing mechanism which comprises a cylinder in which a piston is slidably received. 
     
     
         4 . The method of  claim 1  wherein the step of applying comprises applying the first force with a force producing mechanism which comprises a threaded rod which threadedly engages a threaded hole wherein rotation of the threaded rod causes movement the first backing member. 
     
     
         5 . The method of  claim 1  further comprising the steps of
 providing a second backing member which is movable relative to the sidewall and in contact with the first seal; and 
 applying a second force to the second backing member to force the first seal against the ingot along the secondary chamber. 
 
     
     
         6 . The method of  claim 5  wherein the step of applying the second force occurs after the step of applying the first force. 
     
     
         7 . The method of  claim 1  further comprising the steps of
 providing a second backing member which is movable relative to the sidewall and in contact with a compressible second seal; and 
 applying a force to the second backing member to force the second seal against the ingot along the secondary chamber. 
 
     
     
         8 . The method of  claim 1  further comprising the step of detecting loss of inert gas from the interior chamber. 
     
     
         9 . The method of  claim 8  wherein the step of detecting comprises detecting the loss of inert gas with a first inert gas sensor downstream of the first seal. 
     
     
         10 . The method of  claim 9  wherein the step of directing comprises directing the ingot adjacent a compressible second seal; and the first inert gas sensor is upstream of the second seal. 
     
     
         11 . The method of  claim 10  further comprising the step of detecting loss of inert gas from the interior chamber with a second inert gas sensor downstream of the second seal. 
     
     
         12 . The method of  claim 8  further comprising the step of pumping inert gas into the interior chamber in response to the step of detecting. 
     
     
         13 . The method of  claim 8  wherein the step of applying is in response to detecting the loss of the inert gas. 
     
     
         14 . The method of  claim 13  wherein the step of detecting comprises detecting the loss of inert gas with a first inert gas sensor downstream of the first seal. 
     
     
         15 . The method of  claim 14  wherein the step of directing comprises directing the ingot adjacent a compressible second seal; and the first inert gas sensor is upstream of the second seal; and further comprising, after the step of detecting loss with the first sensor, the step of detecting loss of inert gas from the interior chamber with a second inert gas sensor downstream of the second seal. 
     
     
         16 . The method of  claim 15  wherein the step of applying the first force comprises the step of moving the first backing member from an inactivated position to an activated position; and further comprising the steps of
 providing a second backing member which is movable relative to the sidewall and in contact with the second seal; 
 applying a second force to the second backing member to force the second seal against the ingot along the secondary chamber; and 
 moving the first backing member from the activated position to the inactivated position after the step of applying the second force. 
 
     
     
         17 . The method of  claim 1  wherein the step of applying comprises applying the first force with a spring. 
     
     
         18 . The method of  claim 1  wherein the step of applying comprises applying the force to the first backing member to force the first seal against a compressible second seal and the second seal against the ingot along the secondary chamber. 
     
     
         19 . A method comprising the steps of;
 forming an ingot in an interior chamber;   directing the ingot downstream from the interior chamber into a secondary chamber and through a compressible annular first seal within the secondary chamber; and