Patent ID: 6615709
Filing Date: 2003-09-09
Classification: D21G,G01H

Abstract:
A method for detecting contamination and damage of a roll face (10) in a calender for paper, comprising the steps of:detecting and processing vibrations occurring in connection with a frame part (100) and a bearing support (18) of a calender; providing at least one vibration detector (40; 41 . . . 46; 41a . . . 46a, 41b . . . 46b) for detecting said vibrations, wherein said at least one vibration detector is in connection with the bearing supports of calender rolls (11 . . . 16) and in connection with the frame part (100) related to said bearing supports, by means of which vibration detector(s) the calender roll(s) (11 . . . 16) is/are identified from which the vibration derives; wherein vibrations in the roll frame and roll bearings of a roll or rolls that forms/form a calendering nip or nips (N1 . . . N10) are detected by means of at least one pair of detectors, and that the location of the source (11) of disturbance in the axial direction of said roll is determined based on the phase difference (&phgr;) of the vibrations arriving in the different detectors (41 . . . 46) in a pair of detectors (41a, 41b . . . 46a, 46b); and wherein the condition of the bearings in the calender is monitored by the detectors (41 . . . 46) being placed in connection with the bearings of the rolls (11 . . . 16) to be monitored.