DRYING GROUP OF A DRYING PART FOR RAIL-SHAPED MATERIAL AND USE OF A DRYING GROUP FOR STEP-BY-STEP REDUCTION OF STEAM PRESSURE INSIDE THE MATERIAL

摘要

The drying group of the drying section of a machine for a web material, and especially a papermaking machine, has a number of permeable drying blankets (9,11,13,15) at the drying cylinder (1), passing round it over each other, with at least two blankets at different positions on the peripheral surface of the drying cylinder (1). Pref. the drying blankets (9,11,13,15) have different permeabilities, decreasing from the lowest level at the drying cylinder (1), outwards. The angle (a-d) round the drying cylinder (1), covered by the drying blankets (9,11,13,15), decreases outwards from the lowest level. The strength of the innermost blanket (9) is less than the others (11,13,15), and it is finer and/or thinner than them. The drying blankets (9,11,13,15) are applied simultaneously or in succession to the web material. The system uses 2-4 blankets, in a drying group in a single row, with alternating drying cylinders and deflection rollers in separate rows, using drying suction rollers for the path deflection. The drying cylinders and the deflection rollers have about the same dia..