Metso Paper Inc.

Valmet Corporation

Pentti Nore

Sirpa Rasku

Eija Tiainen

Olli Toermaekangas

Jukka Tenhunen

Pekka Kotovuori

Arto Karjalainen

Leena Otsomaa

Tuula Koskelainen

Eero Suomi

Tapio M&auml;enp&auml;&auml;

Tapio M&auml;enpaa

The invention concerns a method for detecting a contamination and damaging of a face ( ) that runs through a nip or nips (N . . . N ) in a calendar for paper. In the method vibrations occurring in connection with the constructions ( ) of a calendar are detected and processed. The vibrations are detected by at least one vibration detector ( ) fitted in connection with the bearing supports of calendar rolls ( ) or in connection with constructions ( ) related to said bearing supports. By the way of these vibration detectors the calendar roll(s) ( ) is/are identified from which the vibration derives. In the method , it is possible to observe the rotation of all of the rolls to be monitored and to measure vibration from any suitable point whatsoever, for example from the frame ( ) of the machine, by employing at least one vibration detector ( ), the time (T ) of the cycle of the vibration signal obtained from said detector(s) being compared with the numbers of revolutions of the rolls to be monitored. In this way, the source of the disturbance is determined, and action is taken in order to eliminate the disturbance.

Method for detecting contamination and/or damaging of a face that runs through a nip or nips in a calendar for paper

A method for detecting contamination on or damage to a web-contacting face in a paper machine or a paper finishing machine, including the steps of detecting vibrations of the web-contacting face over a period of time by means of a plurality of detectors arranged in association with the machine and determining the location of the contamination on or damage to the web-contacting face based on the time the vibrations were detected.

Method for detecting contamination and/or damage in a face running through a nip in a paper machine or in a paper finishing machine

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Kajaani, Finland

Arto Karjalainen