| 摘要 |
This specification describes a method and an arrangement for quick-opening a set of rolls in a multi-roll calender (10), in which a paper or board web (W) to be cal- endered is passed through calendering nips (N1-N9) formed by a deflection- compensated upper roll (13), a deflection-compensated lower roll (14) and two or more intermediate rolls (15-22) arranged between the upper and lower rolls (13, 14), which rolls (13-22) are arranged as a set of rolls (12) and in which calender the intermediate rolls (15-22) are carried by hydraulic relief cylinders (155-225) for relieving nip load caused by the masses of the bearing housings (151-221) of the intermediate rolls (15-22) in question and auxiliary devices (154-224) related to them. For opening the calendering nips (N1-N9) in the quick opening of the set of rolls (12), the hydraulic load pressures of the deflection-compensated rolls (13, 14) of the set of rolls are discharged, the shell of the lower roll (14) of the set of rolls is lowered downwards, and the relief pressures of the relief cylinders (155-225) of the hydraulic relief devices of the intermediate rolls (15-22) and the load cylinders (143; 146) of the lower roll (14), which are conventional basic hydraulic cylinders without separate quick-opening cylinders, are relieved totally or partly. In the method and the arrangement, the use of both a cutting blade (230) and a cut-off blow (231) can be utilised. |
