Method for producing a tube made of quartz glass using low internal pressure and control of diameters

US6516636B1 · kind B1 · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Frank Gänsicke · Geiselbach, DE
• Oliver Ganz · Könnern, DE
• Harald Hain · Alzenau, DE
• Thomas Bogdahn · Karlstein, DE
• Oliver Humbach · Dortmund, DE

Key dates

• Filing date: Aug 2, 2000
• Grant date: Feb 11, 2003
• Expiry date: Aug 2, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03B23/047
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

In a known method for the manufacture of a tube made of a vitreous material, especially of quartz glass, a hollow cylindrical semifinished product made of a vitreous material is carried essentially vertically to a heating zone, wherein it is heated and drawn off downwards—without the use of tools—to the tube by forming a transitional area from semifinished product to tube, while diameter and wall thickness of the tube are continuously measured, and the tube's measured geometrical data being used to generate a control signal with the aid of which a pressure difference is regulated between pressure P1 in the interior space of the semifinished product, the transitional area and the tube, as well as pressure P2 in the heating chamber which is regulated in the heating zone at least in the transitional area from semifinished product to tube and its adjacent tube area. This method is to be developed further so as to enable the processing of a broader spectrum of hollow cylindrical semifinished products to tubes with the desired inside and outside dimensions. This task is solved according to the invention such that for the manufacture of tubes with the ratio of their outside di…