EP 0936307 A3 20000524 - Drying section and method of operating such a drying section
Title (en)
Drying section and method of operating such a drying section
Title (de)
Trockenpartie sowie Verfahren zum Betreiben einer solchen Trockenpartie
Title (fr)
Section de séchage et procédé de fonctionnement d' une telle section de séchage
Publication
Application
Priority
DE 19805723 A 19980212
Abstract (en)
[origin: EP0936307A2] During the operation of a web drying section of a papermaking machine, the shrinkage in the web (12) across the direction of web travel is set or controlled so that at least one and preferably several zones give a free and unimpeded shrinkage in the web (12). During the operation of a web drying section of a papermaking machine, the shrinkage in the web (12) across the direction of web travel is set or controlled so that at least one and preferably several zones give a free and unimpeded shrinkage in the web (12). The lateral shrinkage of the web (12) is controlled by the number of zones with a free shrinkage and/or the position within the drying section (10). A free web shrinkage zone is established at least in the trailing part of at least one drying group (14), in the direction of web travel, and at least in a trailing zone of the drying section (10). The lateral shrinkage is controlled so that a generally flat shrinkage development is formed across the web and especially at the edges of the web. An Independent claim is included for a drying section (10) at a papermaking machine with a fourdrinier (22) to support the web (12) at least at an initial zone of the drying section (10), where the web and fourdrinier pass through together. The web (12), when detached from the fourdrinier (22), is supported by a gas cushion round the web guide (20) without physical contact and/or the web is blown clear of the fourdrinier by a gas medium, to give a zone where the web can shrink freely. A further Independent claim is included for a roller with a drilled and perforated roller mantle, with the main roller zone connected to a compressed air supply. The perforations at the end zones can be linked selectively to the compressed air or a vacuum. The perforations in the main and end roller zones are separated by a dividing wall, or a moving slide is used to block some perforations and leave others free, while opening and closing the connection to the vacuum source.
IPC 1-7
IPC 8 full level
D21F 5/04 (2006.01)
CPC (source: EP US)
D21F 5/042 (2013.01 - EP US)
Citation (search report)
- [DXA] DE 29616569 U1 19970102 - VOITH SULZER PAPIERMASCH GMBH [DE]
- [A] DE 4241400 A1 19930624 - ESCHER WYSS GMBH [DE]
- [A] WO 9530795 A1 19951116 - VOITH SULZER PAPIERMASCH GMBH [DE], et al
- [A] DE 3630571 A1 19870326 - VALMET OY [FI]
- [A] DE 29521501 U1 19970528 - VOITH SULZER PAPIERMASCH GMBH [DE]
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
EP 0936307 A2 19990818; EP 0936307 A3 20000524; DE 19805723 A1 19990819; US 6145218 A 20001114
DOCDB simple family (application)
EP 98123743 A 19981214; DE 19805723 A 19980212; US 24695199 A 19990209