Production of cylindrical, transparent quartz glass moldings comprises deposition of silica particles to form porous soot preform which is sintered in vitrification furnace below atmospheric pressure and cooled using gas fed into it

摘要

Production of cylindrical moldings of transparent quartz glass comprises deposition of layers of silica particles to form a cylindrical, porous soot preform (3). This is then sintered in a vitrification furnace (10) below atmospheric pressure and is cooled using a gas (18) fed into the furnace. An independent claim is included for vacuum furnaces for carrying out the method which are fitted with an external recirculating pipe (15) for cooling gas, in which a heat exchanger (17) and fan (16) are mounted.