Method and apparatus in the drying section of a paper making machine for speeding the threading of a paper or paperboard web
US5019213A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1990 |
| Grant date | May 28, 1991 |
| Priority date | — |
| Expiry date | Apr 24, 2010 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21F5/042
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus in a drying section of a paper making machine wherein a so-called single-wire draw is applied and wherein blow boxes (20) are used, which are intended to prevent phenomena that disturb the mutual support contact between the web (W) and the drying wire (12). The blow boxes (20) extend across the entire width of the web (W), and they communicate with members (17, 18, 21, 22) that supply blow air, and they are provided with at least two nozzle slots (13, 14) transverse to the running and longitudinal direction of the web (W) as well as with a carrier face (16) between said nozzle slots. Negative pressure is produced in the space (A-) defined by the carrier face (16) and the drying wire (12) by means of the ejection and prevention effects of the air jets (F.sub.1, F.sub.2) blown through the nozzle slots (13,14). In order to speed the threading of the web (W), in the blow boxes (20) the blow sections (24.sub.k+1. . . 24.sub.N ) that remain outside the transverse area (A) of the leader band (R) are closed. The blowing, which has thereby been intensified, is applied through both of the opposite nozzles (13, 14) of the blow boxes (20) in connection with the threading…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.