Molten metal transfer pipe

Abstract

A transfer pipe for molten metal includes a pipe wall comprised of graphite or ceramic. The graphite ceramic pipe wall can be surrounded by a pipe wall comprising a low thermally conductive material. Both the graphite or ceramic pipe wall and the low thermally conductive pipe wall can be encased in a rigid wall, for example steel. The transfer pipe can communicate with a molten metal pump to provide a system for moving molten metal.

1 . A molten metal transfer pipe comprising: 
 an inner pipe wall comprising graphite or ceramic; and    a metal outer pipe wall that receives the inner pipe wall.    
   
   
       2 . The pipe of  claim 1 , wherein the inner pipe wall is cemented to the outer pipe wall.  
   
   
       3 . The pipe of  claim 1 , wherein the inner pipe wall comprises a graphite laminate.  
   
   
       4 . The pipe of  claim 1 , further comprising an intermediate pipe wall interposed between the inner pipe wall and the outer pipe wall.  
   
   
       5 . The pipe of  claim 4 , wherein the intermediate pipe wall comprises a low thermally conductive material.  
   
   
       6 . The pipe of  claim 4 , wherein the intermediate pipe wall comprises an alumino-silicate material.  
   
   
       7 . The pipe of  claim 4 , wherein the intermediate pipe comprises fiber sheet.  
   
   
       8 . The pipe of  claim 4 , wherein the intermediate pipe comprises extruded fiber.  
   
   
       9 . A method for manufacturing a molten metal transfer pipe comprising: 
 forming a graphite or ceramic inner pipe wall; and    inserting the inner pipe wall into a rigid non-ceramic pipe wall.    
   
   
       10 . The method of  claim 9 , further comprising affixing the inner pipe wall to the rigid pipe wall.  
   
   
       11 . The method of  claim 9 , further comprising wrapping a low thermally conductive material around the inner pipe wall.  
   
   
       12 . The method of  claim 11 , further comprising curing the low thermally conductive material.  
   
   
       13 . The method of  claim 11 , wherein the step of inserting the inner pipe wall further comprises inserting the graphite pipe wall and the low thermally conductive material into the rigid pipe wall.  
   
   
       14 . The method of  claim 9 , further comprising interposing a low thermally conductive material between the inner pipe wall and the rigid pipe wall.  
   
   
       15 . The method of  claim 14 , wherein the step of interposing a low thermally conductive material comprises injecting low thermally conductive material into a gap between the inner pipe wall and the rigid pipe wall.  
   
   
       16 . A molten metal transfer pipe comprising: 
 an inner graphite or ceramic pipe wall;    an intermediate pipe wall comprising a low thermally conductive material; and    a rigid outer pipe wall.    
   
   
       17 . The pipe of  claim 16 , wherein the rigid outer pipe wall comprises steel.  
   
   
       18 . The pipe of  claim 16 , wherein the low thermally conductive material comprises an alumino-silicate material.  
   
   
       19 . A method for manufacturing a molten metal transfer pipe fitting comprising: 
 forming a first graphite or ceramic portion;    removing material from the first graphite or ceramic portion to form a first graphite or ceramic wall;    forming a second graphite portion having a complementary shape to the first graphite portion;    removing material from the second graphite portion to form a second graphite wall; and    attaching the first graphite wall to the second graphite wall.    
   
   
       20 . A molten metal system comprising: 
 a means for moving molten metal;    a transfer pipe in communication with the means for moving molten metal, the transfer pipe including an inner pipe wall comprising graphite or ceramic and a metal outer pipe wall that receives the inner pipe wall.