Method and device for the control and/or monitoring of the drying process of a Yankee cylinder

摘要

The invention relates to a method for the control and/or monitoring of the drying process of a web (W) taking place on the Yankee cylinder, the air distribution system of the Yankee cylinder being divided, expediently into three parts, and a computer being used in the method for the control of the process. In the method, a process model is applied which is put forward on the basis of trial runs, on-line measurements and/or drying theory of the process to be controlled or its equivalent. Grade-specific desired value parameters corresponding to the web grade to be run are input from a so-called grade card file or recipe card file. New output values are input into the simulation programme at specific time intervals, measured values of the process parameters obtained from various measuring transmitters of the drying process and, possibly, web samples and coating samples analysed in the laboratory, are used for this. For the purpose of minimising the inaccuracies of the process model, an adaptive process model is applied in the method, for which purpose one specific or several specific parameters in the process are left as variables which are adapted in the correct direction, based on the new output values of the process, in such a way that the process model, as a result, gives values for the measured parameters corresponding to the measured results.