Heatable variable crown roll.

摘要

The invention concerns a heatable variable crown roll, in particular a press roll or a calender roll (10) in a paper or board machine, comprising a hollow, tubular roll mantle (12), which is provided with heating means for heating of the roll mantle, said heating means comprising ducts (1;21), formed into the roll mantle (12), and electric resistors (2) fitted in said ducts (1;21) and connected to a voltage source, said roll being provided with a non-revolving roll axle (11) arranged inside the tubular roll mantle (12) and with crown variation means (14) acting upon the inner face of the roll mantle (12). The electric resistors (2) in said ducts (1;21) in the roll mantle (12) have been divided into zones (Z1, Z2, Z3, Z4) in the axial direction of the roll (10), and currents of different intensities are arranged to be fed into the different zones (Z1, Z2, Z3, Z4) to produce different heating effects in the different zones of the roll (10).