Burner for glass particle synthesis having a port with an extended outer wall

摘要

A concentric multi-tubular burner (16, Fig 3A) for the synthesis of glass particles comprises a centre port group 5 which includes raw material, combustible and oxygen gas jet ports 1-4 and whereby the oxygen port 4 is positioned outside of the other ports 1-3 and which its outer wall 'a' protrudes towards burner head (in the 'gas jet direction') more than the inner wall by a length no less than 30 times as large as the gap b0 between the inner surface of the outer wall and the outer surface of the inner wall. A method of production is also disclosed which uses this burner to produce porous glass by controllably jetting the oxygen gas from port 4 with a flow rate ranging between 3 and 50 m/s.