초록 ▼

In furnaces for producing high purity fused silica glass boules, the refractory in the area of the burner holes reaches such elevated temperatures that cause impurities to leach out and the dissociation of the refractory, causing contamination of the silica glass. In order to reduce the temperature

In furnaces for producing high purity fused silica glass boules, the refractory in the area of the burner holes reaches such elevated temperatures that cause impurities to leach out and the dissociation of the refractory, causing contamination of the silica glass. In order to reduce the temperature of the burner hole refractory, a porous insert or liner is positioned within the burner hole and a suitable gas is supplied thereto. The gas diffuses through the porous liner and not only cools the liner and refractory, but also forms a boundary layer along an inside surface of the insert that prevents particle buildup. The cooling of the insert and surrounding burner hole refractory prevents contamination of the silica glass from the refractory.

대표청구항 ▼

1. A furnace for producing silica glass which comprises:said furnace having a refractory crown, at least one burner hole extending through said refractory crown, a burner positioned above said crown for providing a flame within and along the extent of said burner hole, porous insert means positioned

1. A furnace for producing silica glass which comprises:said furnace having a refractory crown, at least one burner hole extending through said refractory crown, a burner positioned above said crown for providing a flame within and along the extent of said burner hole, porous insert means positioned within said burner hole for cooling the refractory about said burner hole and for preventing contamination of the glass from such refractory, and said porous insert means for cooling the refractory includes a porous wall portion in open communication with an interior portion of said burner hole and extending along the extent of said burner hole.