METHOD FOR DETECTING CONTAMINATION AND/OR DAMAGING OF A FACE THAT RUNS THROUGH A NIP OR NIPS IN A CALENDER FOR PAPER

摘要

The invention concerns a method for detecting contamination and/or damaging of a face (10) that runs through a nip or nips (N1...N10) in a calender for paper. In the method vibrations occurring in connection with the constructions (18, 100) of a calender are detected and processed. The vibrations are detected by means of at least one vibration detector (40; 41...46; 41a...46a, 41b...46b) fitted in connection with the bearing supports of calender rolls (11...16) or in connection with constructions (18, 100) related to said bearing supports. By means of these vibration detectors the calender roll(s) (11...16) 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 (100) of the machine, by employing at least one vibration detector (40), the time (Tr) 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.