METHOD AND ARRANGEMENT FOR PREVENTING VIBRATIONS IN A MULTI-NIP CALENDER OR CALENDER ARRAY

摘要

The invention relates to a method for preventing vibration in a multi-nip calender (1) or array of multi-nip calendars, each multi-nip calender comprising a lower roll (3; 40), an upper roll (3; 30) and two or more intermediate rolls between the lower roll and the upper roll. The fibre web can be conveyed through the roll nips of two or more multi-nip calenders with these roll nips closed. The intermediate rolls (3) are equipped with load-relieving means and both the upper roll (3; 30) and the lower roll (3; 40) are equipped with loading means within these rolls and loading means are connected to the lower roll (3; 40) and/or the upper roll (3; 30) for loading these rolls from the outside in a direction parallel with the calender plane. The method comprises intermittent or continuous changes of the running parameters (9) influencing the calendering impulse of one or more selected roll nips (N), with the overall calendering impulse (9) of the calender or calender array and/or the quality variables (21) fo the fibre web remaining substantially constant and/or within predetermined limits.