Papermaking machine

Abstract

A papermaking machine including a Yankee including a body provided with a metal mantle with circular cross-section and two end heads on which are formed or mounted two respective coaxial pins arranged along a rotation axis of the Yankee, the body being configured to rotate with a predetermined angular speed around said rotation axis. Inside the body is arranged a fixed electromagnetic induction heating system including one or more inductors interacting electromagnetically with the mantle to produce induced electric currents in the same mantle, the inductors being arranged near the radially innermost surface of the mantle. In the machine is arranged a structured web configured for transporting a sheet of fibrous material up to the contact of the latter with the mantle of the Yankee.

1 - 12 . (canceled) 
     
     
         13 . A papermaking machine, comprising: a Yankee having a body comprising a metal mantle with circular cross-section and two end heads on which are formed or mounted two respective coaxial pins arranged along a rotation axis of the Yankee, said body being configured to rotate with a predetermined angular speed around said rotation axis, wherein inside said body is arranged a fixed electromagnetic induction heating system comprising one or more inductors interacting electromagnetically with the mantle to produce induced electric currents in the same mantle, said one or more inductors being arranged near the radially innermost surface of the mantle, and in which is arranged a structured web configured for transporting a sheet of fibrous material up to the contact of the latter with the mantle of the Yankee. 
     
     
         14 . The papermaking machine according to  claim 13 , wherein the Yankee has an external diameter between 2.00 m and 7.500 m, and the mantle has an axial length between 3.00 m and 7.400 m. 
     
     
         15 . The papermaking machine according to  claim 13 , wherein the electromagnetic induction heating system extends axially, parallel to the rotation axis of the Yankee, and along the inner surface of the mantle, but is shorter than the inner surface of the mantle, leaving a free space in front of each of the end heads. 
     
     
         16 . The papermaking machine according to  claim 13 , wherein the radially outermost side of the electromagnetic induction system is at a radial distance from the internal surface of the mantle is between 20 cm and 1 mm. 
     
     
         17 . The papermaking machine according to  claim 13 , wherein said electromagnetic induction system comprises a single inductor in the form of a solenoid developed around the rotation axis of the Yankee, the solenoid being formed by coil turns concentric to said rotation axis. 
     
     
         18 . The papermaking machine according to  claim 13 , wherein said electromagnetic induction system comprises a single toroidal inductor developed parallel to the rotation axis the Yankee. 
     
     
         19 . The papermaking machine according to  claim 13 , wherein said electromagnetic induction system includes a plurality of inductors, each of which comprises a solenoid developed around the axis of the Yankee and formed by coils concentric to said axis. 
     
     
         20 . The papermaking machine according to  claim 13 , wherein said electromagnetic induction system comprises a plurality of inductors axially placed side by side. 
     
     
         21 . The papermaking machine according to  claim 13 , wherein said electromagnetic induction system comprises a plurality of inductors, each of which consists of a solenoid formed by coils wound around respective radial axes. 
     
     
         22 . The papermaking machine according to  claim 13 , wherein said electromagnetic induction system comprises a plurality of inductors arranged circumferentially around the axis of the Yankee. 
     
     
         23 . The papermaking machine according to  claim 17 , wherein the inductor or the inductors are at a radial distance from the inner surface of the mantle and the inductors are formed by coils comprising conductors with a predefined diameter spaced apart by a pitch of predefined value, wherein the value of the said radial distance is less than or equal to the difference between said pitch and said diameter. 
     
     
         24 . The papermaking machine according to  claim 17 , wherein the inductor or the inductors have a side radially closer to the mantle and a side radially more distant from the mantle, wherein said side radially closest to the mantle is at a radial distance from the inner surface of the mantle, the inductors are formed by coils comprising conductors of predefined diameter spaced from each other by a pitch of predefined value, wherein the value of said radial distance is less than or equal to the difference between said pitch and said diameter.