The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 10, 2002
Filed:
Aug. 31, 2001
Metso Paper, Inc., Helsinki, FI;
Abstract
A method for controlling the drying process taking place in the dryer section of a paper machine. The dryer section comprises at least one drying cylinder unit and at least one air impingement unit. Optimal evaporation is first compiled in a manner known, for example, on the basis of a recipe or by utilising a machine-direction quality model or quality profile, when the geometry of the dryer section, the process parametersrequired, such as machine speed, paper grade and total evaporation required are known. Limit values are calculated for at least two controlled variables of the dryer section, such as the steam pressure and the temperature of blowing air, making use of drying quality models, such as models representing the adhesion and brightness of paper. After this the dryer section is divided an the basis of the distribution formed by the limit values of the controlled variables into drying segments, so that in two adjacent segments, the limit value of at least one controlled variable is different. The drying process is controlled by adjusting the controlled variables in each drying segment, within the limit values of the controlled variables.