Loading patent…
AssigneeHeraeus Quarzglas GmbH & Co. KG
InventorsMatthias SÖHN, Boris GROMANN, Eduard VISNOW
Estimating the term…
In a method of manufacturing a tube of quartz glass by molding a hollow cylinder having a wall thickness of at least 20 mm, the cylinder is continuously fed under rotation about a rotational axis into a heating zone at a relative feed rate VC, softened and radially expanded under the effect of a gas pressure. A tube strand is continuously formed and is withdrawn at a withdrawal rate VT. In order to mold thick-walled initial hollow cylinders of quartz glass into tubes with larger diameter, the gas pressure is used as an actuating variable of a diameter regulation for the tube outer diameter or for a geometrical correlated parameter thereof, and in a pressure build-up phase the gas pressure is gradually increased from a lower initial value to a higher final value, and that the following applies to the ratio of VC and VT:VT=VC±0.2·VC.
A method of manufacturing a tube of quartz glass by molding a hollow cylinder having a hollow cylinder bore, an outer diameter Ca, an inner diameter Ci and a wall thickness which is at least 20 mm, by continuously feeding it under rotation around a rotational axis into a heating zone at a relative feed rate VC, softened therein in areas, and the softened area being radially expanded under the effect of a gas pressure applied in the hollow cylinder bore, and a tube strand having an outer tube diameter Ta, a tube inner diameter Ti and a tube wall thickness being continuously molded from the softened area and withdrawn at a withdrawal speed VT, characterized in that the gas pressure is used as an actuating variable of a diameter regulation and/or a diameter control for the tube outer diameter or for a geometrical parameter correlated with the tube outer diameter, and in that in a pressure build-up phase the gas pressure is gradually increased from a lower initial value to a higher final value, and in that the following applies to the ratio of VC and VT:VT=VC±0.2·VC.
A quartz glass tube having a tube outer diameter Ta, a tube inner diameter Ti, a tube wall thickness, an outer lateral surface and an inner lateral surface, characterized in that it has a fire-polished outer lateral surface and in that for the tube outer diameter Ta, the tube inner diameter Ti and the tube wall thickness there applies:
Dependencies are inferred from the claim text.