Patent ID: 7143608
Filing Date: 2006-12-05
Classification: C03B,Y02P

Abstract:
1. A method for producing porous glass body by a vapor phase synthesis method in which glass raw material gas undergoes a hydrolytic reaction or an oxidation reaction in flames, said method comprising: using a glass particles synthesizing burner of a type comprising;  a center port group including: a raw material gas jet port; a combustible gas jet port; and an oxygen gas jet port disposed outside the raw material gas jet port and combustible gas jet port, wherein an outer wall of said oxygen gas jet port of said center port group more protrudes toward a head of said burner than an inner wall of said oxygen gas jet port, and a protruding length of said outer wall is not shorter than 30 times as large as a gap between an inner surface of the outer wall and an outer surface of the inner wall of said oxygen gas jet port: jetting the oxygen gas from said oxygen gas jet port of said center port group, with a flow rate which is not lower than 1.2 times as high as an average flow rate of gases jetted from ports inner than said oxygen gas jet port, the average flow rate being total flow rate of inner gases relative to the jet ports sectional area.