Metso Paper Inc.

Keijo Laaksonen

Jorma Haag

A relief cylinder structure for guiding a roll in a multinip calender has a frame and an arm that is arranged to move linearly in relation to the frame. A quick-opening cylinder is placed inside the arm. In a fault situation, the relief cylinder causes the cylinder rolls to move rapidly further away from each other. An auxiliary coupling () opens in a fault situation, wherein the pressure produced in the quick-opening cylinder () is discharged to a hydraulic system in a substantially non-pressurized state. The pressure of the quick-opening cylinder () is thus reduced below the pressure of the main cylinder (), wherein the auxiliary piston () moves towards the end of the arm (). Because the volume of the main cylinder () grows in accordance with the cylindrical space formed inside the arm (), the volume restricted by the frame () of the relief cylinder () is reduced.

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Hyvinkää, Finland

Keijo Laaksonen