Start-up and operating procedure for roll press having an extended nip press with inflatable press jacket

US4707222A · kind A · utility

Assignee

• J.M. Voith GmbH · DE

Inventors

• Josef Mullner · Heidenheim, DE
• Christian Schiel · Heidenheim, DE
• Karl Steiner · Herbrechtingen, DE

Key dates

• Filing date: Mar 28, 1985
• Grant date: Nov 17, 1987
• Expiry date: Mar 28, 2005

Classification

• Technology area (CPC D): Textiles; Paper
• CPC primary: D21F3/0245
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

In an extended nip proess including a stationary support member, a hydraulically actuatable press shoe supported on and extending along the support member and a rotatable counter-roll opposed to and extending along the direction of the press shoe, there is a flexible, tubular press jacket which rotates around the support member and which is sealed so as to be inflatable by air. Before rotation of the counter-roll starts, the press jacket is air inflated and expands to partially wrap around the counte-roll. After rotation of the counter-roll and the press jacket begins, and only after a set minimum velocity has been exceeded, then the press shoe is fluid pressurized against the press jacket. At the time, the air pressure in the press jacket is reduced. Various control devices control the feed of pressure liquid to the press shoe and the feed of air to the press jacket until and then after a minimum speed level is exceeded.