Method and apparatus for producing a crucible of quartz glass

US8789391B2 · kind B2 · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Thomas Kayser · Leipzig, DE
• Walter Lehmann · Leipzig, DE
• Hilmar Laudahn · Bitterfeld-Wolfen, DE

Key dates

• Filing date: Jan 9, 2009
• Grant date: Jul 29, 2014
• Expiry date: May 15, 2032

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B35/002
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The invention starts from a method for producing a crucible of quartz glass in that SiO2 inner layer granules are vitrified in a rotating melting mold, which is covered at least in part by a heat shield, in a light gas-containing atmosphere under the action of a plasma to obtain a transparent inner layer, at least part of the light gas being supplied to the melting mold through a gas inlet of the heat shield. In order to form an inner layer with a particularly low bubble content and with minimal efforts in terms of energy and material, it is proposed that in a layer forming step preceding the vitrifying step a granule layer consisting of the SiO2 inner layer granules is formed on the inner wall of the crucible, and that the plasma zone and the heat shield are movable together with the gas inlet and are moved laterally in the direction of the granule layer during the vitrifying step taken for vitrifying the granule layer.