Vacuum generation in the pocket of a single wire dryer group

US5230168A · kind A · utility

Assignee

• J.M. Voith GmbH · DE

Inventors

• Helmut Heinzmann · Böhmenkirch, DE
• Bernhard Kohl · Heidenheim, DE

Key dates

• Filing date: Oct 22, 1991
• Grant date: Jul 27, 1993
• Expiry date: Oct 22, 2011

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F26B13/18
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

In a single wire dryer group, a paper web travels on one side of a support belt over a first dryer cylinder, then over a guide roll, then over a second dryer cylinder moving through the dryer group. A pocket is defined between the two adjacent dryer cylinders and the guide roll between them. To develop a vacuum within the pocket in the vicinity of the outer surface of the first dryer cylinder, there is a sealing ledge at the support belt at the first dryer cylinder. The sealing ledge is fastened to a sealing ledge support. An air guide surface on the side of the sealing ledge support away from the pocket is curved first in a direction toward the bottom of the pocket and then away from the pocket around axes above the air guide surface. Toward the second cylinder, the sealing ledge support defines an air ejector nozzle. A first air flow induced on the first dryer cylinder is deflected upward around and past the ejector nozzle by the curvature of the air guide surface. A second air flow traveling along the support belt past the second dryer cylinder is induced to pass through and exits through the nozzle. The first and second air flows are then combined at the outlet from the ejector…