| 摘要 |
A method and a device in the drying section or the like of a paper machine o r the like, in which a web (16) being conveyed from the opening nip (K1) betwe en a cylinder (10) and a supporting fabric (18) toward a roll (14), is supporte d by a negative pressure created by a blow box (30) or the like. The negative pressure in the so called intensified negative pressure region (34'), i.e. close to the disengaging point (40) between the supporting fabric and the cylinder, is greater than at a distance from this disengaging point. Accordi ng to the invention the negative pressure is controlled in the intensified negative pressure region (34') according to one or more parameters which act on the runability of the web and which can be varied or which vary during th e run, such as the velocity of the web, the solid contents of the web, the composition of the pulp which is used, the paper or paper board quality whic h is produced, the grammage of the web, a characteristic of the web, such as t he porosity, the traction acting in the web, or the web tension, the cylinder temperature, and/or the running situation, such as a web break, a threading situation, or a normal run, so that the desired runability is maintained between the cylinder (10) and the roll (14). |
