Quick opening of a set of rolls of a multi-roll calender

• Main Author: LAAKSONEN KEIJO
• Format: Patent
• Language: Chinese; English
• Published: 02.09.2009
• Subjects: ACCESSORIES FOR PAPER-MAKING MACHINES; CALENDERS; PAPER-MAKING; PRODUCTION OF CELLULOSE; TEXTILES

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 re