Method for detecting contamination and/or damage in a face running through a nip in a paper machine or in a paper finishing machine
AssigneeValmet Corporation
InventorsEero Suomi, Tapio Mäenp{umlaut over (aa)}, Arto Karjalainen
Life of this patent
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Abstract
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.
Claims20
A method for detecting contamination and/or damage in a face (11,12′) of a roll running through a nip (N) or nips in a calender, comprising the steps of:
- detecting rotational vibrations in said calender caused by contamination or damage to said face during operation or construction of the machine by means of at least first and second detectors (20,21,25) structured and arranged on at least one of said face and a bearing housing supporting said calender roll, said at least a first detector being adapted to measure said vibrations and generate a first time based vibration signal fa(t) and said at least a second detector being adapted to measure said vibrations and generate a second time based vibration signal fb(t), and
- determining the location of said damage and/or contamination (M:M1,M2) on said face to be monitored (11, 12′) based on said first time based vibration signal fa(t) and said second time based vibration signal fb(t).
A method for detecting contamination on or damage to a web-contacting face of a roll running through a calender defining a nip, comprising the steps of:
- measuring rotational vibrations of the web-contacting face over a period of time by means of a at least a first and second detector arranged on at least one of said web-contacting face and a bearing housing supporting said roll, wherein said vibrations are the result of at least one of a deposition of contamination and damage of said face during operation or construction of the machine;
- generating a first time based vibration signal fa(t) based upon said measurements of said first detector and generating a second time based vibration signal fb(t) based upon the measurements of said second detector,
- determining the location of the contamination on or damage to the web-contacting face based on said first time based vibration signal fa(t) and said second time based vibration signal fa(t).
In a calender having a frame, at least one roll having web-contacting face defined in connection therewith, and bearing for supporting ends of each of the at least one roll on the frame, the improvement comprising:
- at least a first and second detector arranged on at least one of said web-contacting face and said bearings for detecting rotational vibrations of the web-contacting face over a period of time, wherein said bibrations are the result of at least one of a deposition of contamination and damage to said face during operation or construction of said machine, and wherein said first detector is structured and arranged to generate a first time based bibration signal fa(t) and said second detector is structured and arranged to generate a second time based bibration signal fb(t) such that a location of contamination on or damage to the web-contacting face is able to be detected based on the first and second time based vibration signals.
Dependencies are inferred from the claim text.