Thermo roll
A heatable and/or coolable roll, i.e. a thermo roll, of a fibrous web machine for the treatment of a fibrous web, is, for example, for pressing and/or calendering the fibrous web in contact, i.e. in a nip, between the thermo roll and a backing member which is in contact with the thermo roll or for drying or cooling the fibrous web on the shell surface of the thermo roll. A semi-finished product of a thermo roll is manufactured using a thermo roll.
1 - 111 . (canceled)
112 . A thermo roll, in a fibrous web machine for pressing, drying, or cooling a fibrous web, comprising:
a roll shell having an outer web engaging surface, and a thermal conductivity between 300-350 W/mK.
113 . The thermo roll of claim 112 wherein the roll shell is a CuCrZr alloy (copper-chrome-zirconium), having a density of 8-10 g/cm 3 and an elastic modulus of 100-150 GPa.
114 . The thermo roll of claim 112 further comprising a wear resistant coating covering the outer web engaging surface.
115 . A thermo roll, in a fibrous web machine for pressing, drying, or cooling a fibrous web, comprising:
a rotating cylindrical shell having an inner surface, and a central axis which defines an axial direction along the axis;
a body formed of at least one part, the body having an outer surface, the body arranged inside the shell;
at least one heat transfer medium flow passage defined by the inner surface of the shell and the outer surface of the body;
a quantity of heat transfer medium within the at least one heat transfer medium flow passage;
a first heat transfer medium conveying means for passing the heat transfer medium into the at least one heat transfer medium flow passage, the first heat transfer medium conveying means having a plurality of inlets into the at least one heat transfer medium flow passage;
a second heat transfer medium conveying means for removing the heat transfer medium from the at least one heat transfer medium flow passage, the second heat transfer medium conveying means having a plurality of outlets from the at least one heat transfer medium flow passage;
a means for controlling flow of the heat transfer medium between the first heat transfer medium conveying means and the second heat transfer medium conveying means;
wherein the inlets into the at least one heat transfer medium flow passage are connected to the first heat transfer medium conveying means, such that the heat transfer medium is supplied into the at least one heat transfer medium flow passage at more than one position along the axis of the cylindrical shell; and
wherein the outlets from the at least one heat transfer medium flow passage are connected to the second heat transfer medium conveying means, such that the heat transfer medium is removed from the at least one heat transfer medium flow passage at more than one position along the axis of the cylindrical shell.
116 . A method for manufacturing a thermo roll for the treatment of a fibrous web, the method comprising the steps of:
forming in a first stage a first layer of a shell of the thermo roll, of a first material with a first manufacturing technique;
forming in a second stage a second layer of the shell of the thermo roll of a second material with a second manufacturing technique different from the first manufacturing technique;
arranging the first layer radially inwardly from the second layer of the shell of the thermo roll;
forming heat transfer medium flow passages, each flow passage being confined within the first material layer, the second material layer, or situated in a boundary zone between said first and second material layers; and
heating the fibrous web with the shell of the thermo roll, with a heat transfer medium, and transferring 100-300 kW/m to the fibrous web with a heat transfer medium temperature of less than 350 degrees C.
117 . The method of claim 116 wherein the step of transferring 10-300 kW/m to the fibrous web is further limited to transferring 200-250 kW/m to the fibrous web.