| 摘要 |
A method and apparatus for the inductive heating of a roll used in the manufacture of paper by means of eddy currents, such as the inductive heating of a calender roll. In the apparatus, pole shoe devices provided with electromagnetic coils are used, by means of which the eddy-current heating is applied only to the surface layer of the roll, the surface layer being constituted of ferromagnetic material, solely from outside the roll. The apparatus comprises several iron cores placed side by side and provided with magnetizing coils. Into each coil, a magnetizing current is passed, the magnetizing current being of adjustable intensity and/or frequency to control the temperature profile of the roll in the axial direction thereof. |
