Quartz fusion furnace and method for forming quartz articles

Abstract

A crucible for melting a silica for fusion of said silica into a desired shape. The crucible having a main body with inner and outer surfaces comprised of a refractory material. In addition, at least a portion of the inner surface includes a barrier layer comprised of a material selected from rhenium, osmium, iridium, and mixtures thereof. An inlet tube to the crucible being provided to supply an oxidizing gas to a melt zone.

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       10 . A furnace for melting silica for fusion into a desired shape, said furnace comprising a body having a melting zone comprising a refractory material wall with a protective lining selected from the group consisting of rhenium, osmium, iridium and mixtures thereof and a drawing zone, said melting zone including a gas feed inlet for introducing an oxidizing gas.  
   
   
       11 . The furnace of  claim 10  wherein said melting zone comprises walls of the refractory material and an inner barrier layer.  
   
   
       12 . The furnace of  claim 11  wherein said barrier layer comprises a material selected from the group consisting of rhenium, osmium, iridium and mixtures thereof.  
   
   
       13 . The furnace of  claim 10  wherein said refractory material wall comprises a refractory material selected from the group consisting of tungsten, molybdenum and mixtures thereof.  
   
   
       14 . The furnace of  claim 11  wherein said barrier layer provides a sealed chamber within said refractory material walls, said gas feed inlet opening into said sealed chamber.  
   
   
       15 . The furnace of  claim 11  wherein said barrier layer is physically separated in at least some areas from said refractory material walls.  
   
   
       16 . The furnace of  claim 15  including a gas feed inlet for introducing between the barrier layer and the refractory material walls.  
   
   
       17 . A fused quartz article produced by a method comprising: 
 feeding a SiO 2  material into a furnace melting zone comprising a refractory material wall comprising tungsten molybdenum or mixtures thereof with a protective lining selected from the group consisting of rhenium, osmium, iridium and mixtures thereof;    feeding a gas mixture comprising at least (1) one inert carrier gas comprising a member selected from the group consisting of a hydrogen carrier gas and a noble carrier gas and (2) an oxidizing gas into the protectively lined furnace melting zone;    fusing the SiO 2 material in the protectively lined melting zone of the furnace in the presence of the gas mixture; and    drawing the fused SiO 2  material from the furnace to form the fused quartz article. according to the method of  claim 1 .    
   
   
       18 . An optical fiber including a sheath comprising the fused quartz article of  claim 17.