US 2006/0124001 A1 · Method and arrangement for preventing vibrations in a multi-nip calender or calender array

Abstract

Vibration is prevented in a multi-nip calender (1) or an array of multi-nip calendars. Each calender has a lower roll (3; 40), an upper roll (3; 30) and two or more intermediate rolls. A fibre web is conveyed through the closed roll nips of the calenders. The intermediate rolls (3) have load-relieving means and the upper roll (3; 30) and the lower roll (3; 40) have loading means, while 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 running parameters (9) influencing the calendering impulse of one or more selected roll nips (N) are intermittently or continuously changed, such that the overall calendering impulse (9) of the calender or calender array and/or the quality variables (21) of the fibre web remain substantially constant and/or within predetermined limits.

Claims8

Dependent claims

A method for preventing vibrations in a multi-nip calender (1) or an array of multi-nip calenders, 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, a fibre web (W) conveyable through the roll nips (N) of two or more multi-nip calenders with the roll nips closed, the intermediate rolls being equipped with load-relieving means and the upper roll (3;
30) and the lower roll (3;
40) being equipped with loading means within said rolls and the loading means (30c, 40c) being connected to the lower roll (3;
40) and/or the upper roll (3;
30) for loading said rolls from the outside in the direction of the plane (P) of the calender, characterised in that the method comprises continuous or intermittent changes of the running parameters (9) acting on the calendering impulse of one or more selected roll nips (N) so that the overall calendering impulse (11) of the calender or calender array and/or the quality variables (21) of the fibre web (W) remain substantially constant and/or within predetermined limits.

3 more elements

An arrangement for preventing vibrations in a multi-nip calender (1) or an array of multi-nip calenders, each multi-nip calender comprising a lower roll (3;

40), an upper roll (3;
30) and one or more intermediate rolls between the lower roll and the upper roll, the fibre web (W) being conveyable through two or more roll nips (N) of the multi-nip calender with the roll nips closed, the intermediate rolls being equipped with load-relieving means and the upper roll (3;
30) and the lower roll (3;
40) being equipped with loading means within said rolls and loading means (40c, 30c) being connected to the lower roll (3;
40) and/or upper roll (3;
30), respectively, for loading the rolls from the outside in the direction of the plane (P) of the calender, characterised in that the arrangement comprises a control system (7) and a measurement system (6), the control system comprising a calculation unit (51) and a regulation unit (52), the regulation unit (52) allowing continuous or intermittent changes of running parameters (9) acting on the calendering impulse of one or more roll nips on the basis of control commands from the calculation unit (51), so that the overall calendering impulse (11) of the calender or calender array and/or the quality variables (21) of the fibre web remain substantially constant or within predetermined limits.

3 more elements

Dependencies are inferred from the claim text.

Method and arrangement for preventing vibrations in a multi-nip calender or calender array

Life of this patent

Method and arrangement for preventing vibrations in a multi-nip calender or calender array

Life of this patent

Abstract

Claims8