Patent ID: 6588230
Filing Date: 2003-07-08
Classification: C03B,F23C,F23D,F23L

Abstract:
A method for making a fused silica glass comprising:(A) providing a burner for producing silica soot from a plurality of source materials, said burner having a burner face and a tube-in-tube construction which defines a plurality of passages for carrying flows of source materials to the burner face, said burner comprising: (a) a first entrance port which is connected to a first passage defined by a first tube, said first passage extending from the first entrance port towards the burner face; (b) a second entrance port which is connected to a second passage defined by the first tube and by a second tube, said second passage extending from the second entrance port towards the burner face; (c) a third entrance port which is connected to a third passage defined by the second tube and by a third tube, said third passage extending from the third entrance port towards the burner face; (d) a fourth entrance port which is connected to a fourth passage defined by the third tube and by a fourth tube, said fourth passage extending from the fourth entrance port towards the burner face; (e) a fifth entrance port which is connected to a fifth passage defined by the fourth tube and by a fifth tube, said fifth passage extending from the fifth entrance port towards the burner face; and (f) a sixth entrance port which is connected to a sixth passage defined by the fifth tube and by a sixth tube, said sixth passage extending from the sixth entrance port towards the burner face; (B) providing oxygen to the burner's first entrance port; (C) providing a silicon-containing source material to the burner's second entrance port; (D) providing oxygen or an inert gas to the burner's third entrance port; (E) providing oxygen to the burner's fourth entrance port; (F) providing fuel to the burner's fifth entrance port; and (G) providing oxygen to the burner's sixth entrance port; wherein: (i) the sixth tube surrounds the fifth tube which surrounds the fourth tube which surrounds the third tube which surrounds the second tube which surrounds the first tube; and (ii) the silicon-containing source material is a liquid and the second passage comprises a restriction zone for atomizing the liquid, said restriction zone being located between the second entrance port and the burner face.