FI90503B - Process for use in the reconditioning of a roller belonging to a papermaking machine - Google Patents

Description

90503

Method for paper machine roll refurbishment Förfarande vid iständsättning av en Vals account en pappersmaskin 5

The invention relates to a method for repairing a roll of a paper machine.

FI publication 71 508, EP publication 0 397 993, US patent publication 4 548 064 and EP publication 0 154 319 disclose the refurbishment of a paper machine roll by grinding. 10 Measurement during grinding is used to control grinding.

The rolls of the paper machine wear most strongly from the web area, leaving the off-web area to bear. This is the case, for example, for press groove rollers, central rollers and calender rolls. The paper web carries abrasive particles and the roll wears hardest in the area of the paper web, and in the edge area of the roll outside the web there is a load-bearing portion of the roll, whereby the roll pressing becomes incomplete and inaccurate. Since the worst roll profile error occurs at the edge of the track, the above-mentioned wear error is often the first reason why the roll should be removed from the press and re-ground.

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The invention has been found to provide an improvement on the above problem. In the invention, it is realized to grind the rollers forming the press nip from the edge areas with a separate grinding device.

Grinding is done from the side of the roll with the rollers in place on the machine. Grinding is done with either a rotating or non-rotating grinding stone / grinding belt. Said means 25 can be moved in a longitudinal direction of the roll to a suitable position. Roller radial control; that is, the grinding depth is obtained, for example, by means of rollers, slippers or other similar control means adjacent to the grinding point.

The method according to the invention for repairing a paper machine roll is mainly characterized in that the method measures the wear of the roll surface from the roll edge area and when the edge error exceeds a certain maximum permissible error, removing said edge error by grinding the roll from the roll edge to that profile level. , the roll 2 90503 is in the area in contact with the fabric passing through the paper web or the press nip, and that the method performs grinding of the roll forming the press nip with a device arrangement fitted as standard to the roll edge area and thus reduce maintenance costs.

The invention will now be described with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

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Figures 1A and 1B illustrate a problem area of the invention. Figure 1A shows the ground rolls with the nip open.

Fig. 1B shows the rolls of the rolls of Fig. 1A with the press nip open at the stage when the web has worn the surface of the rolls and an off-web bearing area has formed on the edge areas of the rolls.

Figure 2 shows the measurement result of a roll that has passed after four months of use into the measured profile shape shown in the figure.

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Figure 3 shows a press roll assembly in which alternative grinding device arrangements at the edge areas of the roll are placed in connection with the press rolls.

Fig. 4A shows an arrangement of the grinding devices of the press roll, in which by means of a subframe 25 connected to the load arm, the grinding wheel can be turned to a position in the edge area of the roll to perform edge grinding of the roll.

Figure 4B shows the Figure 4A apparatus 4A, the image seen in the direction of arrow D.

Figure 5 shows the position of the device according to the invention in different positions in the press section of the paper machine.

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Figure 1A shows an opened press nip formed by ground rolls. As used herein, a press nip refers to a nip formed by rolls of a paper machine, either groove rolls or smooth rolls, which may be located in a press or calender. As shown in the figure, the paper path W is between the felts Hj and H2. The blankets may be only one 5 (e.g. H]) or there are no blankets at all, in which case the paper web is directly between the roll surfaces. As shown in Fig. 1A, the rolls Tt and T2 are ground and the pressing in the nip between the rolls takes place evenly over the entire width of the paper web W.

Fig. 1B shows the rolls of Fig. 1A in the stage where the surfaces of the rollers T1, T2 are worn from the area of the paper web W and a bearing area K1, K2 is formed on the rolls T1, T2 at the edge areas of the rolls immediately outside the paper web W. The nip between the rollers TL, T2 is shown open.

Figure 2 shows an experimentally measured profile of the press roll along the entire length of the roll. As shown in the figure, a bearing region K is formed on the edges of the roll before the edge area E, where there is a shape error of about 0.25 mm on the surface of the roll and which represents the largest profile error along the entire length of the roll. The grinding of the roll is performed on the basis of said maximum error when the error exceeds a certain value. Thus, if the above-mentioned edge defect K can be eliminated, e.g. according to the invention, by grinding the edge area E, it is possible to considerably lengthen the grinding and maintenance interval of the entire roll.

Fig. 3 shows a press nip assembly formed by the rolls Τ1, Τ2, Τ3, Τ4 of a paper machine, in which a wire-web combination R, .. is passed through the press nips NltN2 and N3. whose configuration in different nips may be different. In the edge region of the rollers, the removal of the edge protrusion K is carried out using the rotating grindstone shown in Fig. 3 by reference numeral 10 and / or the stationary grinding piece shown at reference number 11 in Fig. 3. As shown in Fig. 3, in the lateral position of the roll Tj, there is a belt grinding device 12, the function of which is to eliminate the edge error K. The grinding is performed when the edge error K exceeds the maximum allowed value. The grinding means 10,11,12 are set / 30 can be set on both edge areas of the roll. The edge of the roll is ground to the profile level, 4 90503 which the rolls have in the area of the paper web W. In the ice arrangement, both or only one of the rollers forming the press nip is ground.

Figure 4A shows a grinding device 13 mounted in the lateral position of the roll T. The grinding device 5 13 comprises a loading arm 14 inherent in the press and an actuator 15, preferably a cylinder device, articulated from the joints 16 and 17 so that the articulation point 16 is located on the loading arm 14 and the articulation point The subframe 18 is articulated from the articulation point C to the load arm 14. A slide body 20 comprising a grinding wheel 21 and a motor 22 rotating it 22 is placed in the guides 19 of the subframe 18. The slide body 20 further comprises guides 23 which can be brought against the roller surface T to be adjusted. has adjustable grinding depth.

Figure 4B shows the view of Figure 4A, Figure 4A viewed in the direction of arrow D. The slide body 20 comprises a drive motor 22, the drive wheel 25 of the output shaft 24 of which engages the drive wheel 27 of the shaft 26 rotating the grinding wheel 21. In connection with the slide body 20 there are guides 23 on which the device can be supported on the grinding surface Tj and for adjusting the grinding depth. The guides 23 are preferably rotating rollers.

Figure 5 shows the press section of a paper machine. Figure 5 shows the arrangement of the roll edge grinding device according to the invention at positions Aj, A2, A3. The grinding device is located as standard equipment near the press nip in the edge area of the rollers to be ground, or the grinding device-ice arrangement comprises coupling means in which the grinding device can be easily mounted when performing edge grinding of the roll.

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Claims (1)

A method for repairing a roll (T) of a paper machine, which roll (T) is adapted to be stationary during use in the paper machine application and is adapted to form a press nip with the counter roll, and which method grinds the roll to correct wear using the measurement result in grinding. measuring the wear of the roll surface from the edge area of the roll and when the edge error (K) exceeds a certain maximum permissible error, removing said edge error (K) by grinding the roll (T) from the edge area of the roll to the profile level of the roll in the area is in contact with the fabric passing through the paper web or the press nip, and that the method comprises grinding the press nip forming roll with a device arrangement fitted as standard on the edge region of the roll (T), thereby considerably extending the length profile of the roll (T) thus reducing maintenance costs. 15 ______ - L. motifs and vid vilket förfarande man slipar valsen för corrigering av slitaget och utnyttjar mätresultatet vid slipningen, kännetecknat därav, att man vid förfarandet mäter slitaget av valsytan ätminstone vid kantomrädet av valsen och dä kantet (K) genomic image of a slice of a roll (T) 10 head of a roll of a roll of a roll of a roll of a roll of a roll of a roll of a roll of a roll of a roll (see) valsen som bildar pressnypet med ett anord-ningsarrangemang som är anordnat som standardutrustning pä kantomrädet av valsen (T), varvid man and with the side edge (K) of the slope of the slip-15-rum, the slope of the slope profile of the roll (T) and the slope of the service side.