Dryer section of a paper or board machine

摘要

A high speed dryer section has single-wire draw drying groups (R1, RN). A paper or board web (W) is supported by a wire (F) as it meanders over drying cylinders (20) in an upper row and reversing cylinders/rolls (21) in a lower row. A first cylinder drying group (R1) has at least five drying cylinders. In the first cylinder drying group (R1) a runnability component (30) is placed in a pocket space defined by every two successive drying cylinders (20) and the reversing roll (21) between them and by the drying wire (F) for applying a high under-pressure of 1000-8000 Pa to an area (50Y) in which the web (W) separates from the drying cylinder (20), and by which runnability component (30) a lower under-pressure of 100-500 Pa is produced in at least part of the rest of the pocket space (T).