Paper-making machine twin-blanket drying section - has structured gap between suction deflection rollers in upper row of cylinders and blanket path at lower row to reduce web path

摘要

The drying section of a paper-making machine, with a twin-blanket drying group (13), has rows of upper (18,20) and lower (19) cylinders, and suction path deflection rollers (18') in the upper row. The space between the suction deflection rollers (18') and the blanket path at the lower row at a tangent to them, between guide rollers (29), is free of machinery parts or components. Pref., the gap between the suction deflection roller (18') and the lower blanket path is less than the roller dia. An air blowing chamber (21) is within the loops formed by the blanket paths, opposite the suction deflection rollers (18',19'), to blow air through the two blankets (OF,UF). At least two twin-blanket drying groups (11,12,13) are arranged in succession. At least one blanket drying group, in addition, is at the start of the assembly, where the web (9) together with a single continuous blanket follow a serpentine path together alternating between cylinders and suction deflection rollers. USE/ADVANTAGE - The drying section of the paper-making machine has two rows of cylinders, working with two blankets. The web paths between the upper and lower cylinder rows are reduced by about half in alternating between the rows. The risk of web fracture is greatly reduced, but not wholly eliminated.