Method for producing a large-diameter quartz glass tube

• Main Authors: OBERLE, BURKHARD, SCHENK, CHRISTIAN, FRANZ, BERNHARD, FISCHER, GERO, LEIN, ULRICH, DECLERCK, PELAGIE, LAAZ, ALEXANDER, HOFMANN, ACHIM, GROMANN, BORIS
• Format: Patent
• Language: Chinese; English
• Published: 01.02.2015
• Subjects: CHEMISTRY; GLASS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL

A well-known method for producing a large-diameter quartz glass tube by multi-stage shaping comprises a first shaping step using a forming tool resulting in an intermediate cylinder of quartz glass with an intermediate-cylinder wall thickness and an intermediate-cylinder outer diameter. In a second shaping step at least a longitudinal section of said intermediate cylinder is supplied to a heating zone, heated therein zone by zone to a softening temperature and then it is shaped into the large-diameter quartz glass tube with a final wall thickness and a final outer diameter. Starting for this method and in order to provide a modified method, which under economically reasonable efforts permits the production of quartz glass tubes that even at a large outer diameter of more than 500 mm show a great dimensional stability, the invention proposes that the quartz glass is synthetically produced and has a mean hydroxyl group content of 10 wt. ppm or less, with the additional proviso that when the intermediate cylinde