Metso Paper Inc.

Jorma Haag

Hannu Pullinen

Keijo Laaksonen

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.

Relief cylinder structure of a multinip calender

A multiple-nip calender has a set of rolls () with roll nips (N) between the rolls. A moistening arrangement has a roll means () for moistening the fibre web comprising a damping unit () and rolls () guiding the fibre web (W). The roll means is located in a pocket () adjacent to the line (L) of the aligned set of rolls, the pocket being formed by a space defined by the fibre web (W), one idle roll () in the set of rolls and said roll means (), the fibre web contacting said roll at two locations, in roll nips located on opposite sides of the roll mantle when viewed from the longitudinal axis of the roll, and circulating around the roll means (). The fibre web (W) contacts said roll in the set of rolls preferably in the roll nip immediately preceding a reversing nip (N;N).

Growing community of inventors

Karkkilä, Finland

Jorma Haag