Improved web break strategy using a new approach for steam pressure control in paper machines

In English This paper presents a new strategy for steam pressure control during web breaks in the paper machine. The aim was to restart paper
production with the same drying properties of the cylinder as before the break. A detailed physical dynamic model of the drying cylinder
has been developed. The accuracy of the model has been verified through experiments made at the M-real paper mill in Husum, Sweden.
Verifications are made both during normal operation and during web breaks. The dynamic model has been reduced in order to derive
simple transfer functions which were used to find the optimal steam pressure trajectory during web breaks. The resulting strategy has
been tested on a paper machine with good results and it has been well received at the mill.