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AssigneeValmet Paper Machinery Inc.
InventorJyrki Laitinen
Estimating the term…
The invention concerns a method and a device for measurement of the nip force and/or nip pressure in a nip (N) formed by a revolving roll or a band used in the manufacture of paper. In the method and in the device, a series of measurement detectors (20.sub.1 . . . 20.sub.n) is used, whose detectors (20) are placed across a considerable width of the paper web (W) in the transverse direction of the revolving roll (10) or the band. The measurement signals received from the different detectors (20) are passed to a switching unit (23), whose connectors (24.sub.l. . .24.sub.n) are controlled so that, through the switching unit (23), the signal of each measurement detector (20.sub.l. . .20.sub.n) is alternatingly connected to a telemeter transmitter (26) placed in connection with the revolving roll (10). By means of the telemeter transmitter (26), the series of measurement signals (V.sub.in l. . . V.sub.in n) are transmitted wirelessly to a stationary telemeter receiver (27) placed outside the revolving roll (10).
Method for measuring the nip force and/or nip pressure in a nip (N) formed by a revolving roll or a band used in the manufacture of paper, the method comprising the steps of using a series of measurement detectors (20.sub.l . . . 20.sub.n) that are polyvinylidenedifluoride-film detectors, placing the detectors on the roll in a straight line across a substantial width (W.sub.0) of the paper web (W) in the transverse direction of the revolving roll or the band, passing the measurement signals received from the different detectors (20) to a switching unit (23) whose connectors (24.sub.l . . . 24.sub.n) are controlled so that, through the switching unit (23), the signal of each measurement detector (20.sub.l . . . 20.sub.n) is alternatingly connected to a telemeter transmitter (26) placed in connection with the revolving roll 10 or equivalent, transmitting the series of measurement signals (V.sub.inl . . . V.sub.inn) by means of said telemeter transmitter (26) wirelessly to a stationary telemeter receiver (27) placed outside the revolving roll (10), measuring the distributions of the compression pressure in the nip (N) in both the machine direction (P.sub.M) and in the transverse direction (P.sub.T) and, in the transverse direction, using n=3-20 measurement points and an equal number n of measurement detectors (20).
Method for measuring the nip force and/or nip pressure in a nip (N) formed by a revolving roll or a band used in the manufacture of paper, the method comprising the steps of using a series of measurement detectors (20.sub.l . . . 20.sub.n) that are polyvinylidenedifluoride-film detectors, placing the detectors on the roll in a straight line across a substantial width (W.sub.0) of the paper web (W) in the transverse direction of the revolving roll or the band, passing the measurement signals received from the different detectors (20) to a switching unit (23) whose connectors (24.sub.l . . . 24.sub.n) are controlled so that, through the switching unit (23), the signal of each measurement detector (20.sub.l . . . 20.sub.n) is alternatingly connected to a telemeter transmitter (26) placed in connection with the revolving roll (10) or equivalent, transmitting the series of measurement signals (V.sub.inl . . . V.sub.inn) by means of said telemeter transmitter (26) wirelessly to a stationary telemeter receiver (27) placed outside the revolving roll (10), in addition to measuring the compression force or pressure in the nip (N) and/or the distribution or distributions (P.sub.M, P.sub.T) of said force or pressure, measuring the temperature or distribution of temperature of the roll (10) face or roll coating (11).
Device for measurement of the nip force and/or nip pressure of the distribution of same in a nip (N) formed by a revolving roll (10) or by a corresponding band used in the manufacture of paper, said device comprising a series of polyvinylidenedifluoride-film detectors (20.sub.l . . . 20.sub.n) placed on the revolving roll (10) or the band, which detectors (20) are placed in a straight line, preferably as evenly spaced, in the transverse direction of the roll (10) or band, wherein the device comprises a switching unit (23) fitted in connection with the revolving roll (10) or the band, to which unit the signals received from the different measurement detectors (20) are connected, the device further comprises a telemeter transmitter (26) fitted in connection with the revolving roll (10), to which transmitter the switching unit (23) is fitted to connect the measurement signals of the detectors (20), the device still further comprising a telemeter receiver (27) fitted at the proximity of the telemeter transmitter (26), said receiver being fitted to receive the series of measurement signals (V.sub.inl . . . V.sub.m) transmitted by the telemeter transmitter (26) wirelessly, the series of detectors (20.sub.l . . . 20.sub.n) being composed of a unified, oblong polyvinylidenedifluoride-film strip (30) which has been extended at least a portion of the width (W.sub.0) of the roll (10) or band, metallization patterns (31) being applied onto said polyvinylidenedifluoride-film strip, as active areas, by way of which the compression forces or pressures are measured, the metallization patterns (31) being connected by means of strip conductors (32) to the switching unit (23), said strip conductors (32) consisting of metallizations applied onto said film strip (30).
Dependencies are inferred from the claim text.