Process for the sintering of hollow cylinders of silicon dioxide soot

US5665132A · kind A · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Klaus Ruppert · Siegen, DE
• Uwe Christiansen · Gelnhausen, DE
• Michael Hünermann · Alzenau, DE
• Klaus Dittmer · Gelnhausen, DE
• Anton Steinkohl · Grundau, DE

Key dates

• Filing date: Sep 12, 1995
• Grant date: Sep 9, 1997
• Expiry date: Sep 12, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03B37/01446
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A hollow cylinder is held in a vertical orientation and sent continuously through a heating zone for sintering. In a first phase of the sintering operation, the hollow cylinder stands on a support while the upper end (12) of the cylinder is being sintered. In a second phase the cylinder hangs from a hanging element while its lower end (10) is sintered. A vertical rod is fixed to the base on which the lower end is supported, and extends through the hollow cylinder. A retaining ring is fixed inside the upper end of the hollow cylinder. During the first phase, the upper end vitrifies and contracts so that the retaining ring engages the vertical rod. Longitudinal contraction causes the lower end to lift off the base so that the cylinder is suspended during the second phase.