FI113975B - Apparatus for conditioning a roll particularly one on a paper making machine - Google Patents

Abstract

A method for conditioning a paper makers roll (10) comprises: 1) continuously monitoring during operations the surface or coating; 2) depending upon the measurement results the roll face or coating is cleaned and or ground so that the roll remains in a constant good condition and the paper quality remains at the desired condition : An independent claim is included for an apparatus (20) to complete the method which comprises measuring unit (32) with measuring device (31) to measure the shape and roundness of the roll and the position of the apparatus relative to the roll the unit mounted on doctor beam (11). The detected data is transmitted to processor (33) which depending on the quality of the received data actuates cleaning and conditioning unit (23, 24) which includes grinding belt (22) to operate against the roll as required to recondition the roll during roll operations.

Description

113975

Method and apparatus for rebuilding a roll of a papermaking machine or paper finishing device Förfarande och anordning för underhäll av en Vals i en pappersmask eller en efterbehandlingsanordning för papper 5

The invention relates to a method for reconditioning a roll of a paper machine or paper finishing apparatus, wherein the surface / coating of a roll of a paper machine is cleaned and / or sanded.

The invention also relates to a device for rebuilding a roll of a paper machine and / or a paper finishing device, which comprises means for cleaning and / or grinding the roll.

15

As is known in the art, when used in paper machines and paper finishing machines, the rolls of the paper machines and finishing equipment become soiled, worn and / or damaged, which causes the paper to be manufactured to degrade. As a result, the rollers will need to be cleaned and / or repaired from time to time and the machine will have to be stopped during cleaning / refurbishment. ; , In some cases, the condition of the roller has deteriorated so much that the roller has to be forced! 'to exchange.

I 1

One particular problem with coated rolls is the so-called hot spots, which are formed on the surface of the rolls due to the formation of dirt particles, which results in the formation of hysteresis heat, which causes the roll coating to be damaged at this point. Spot propagation is fast and difficult to locate. In prior art solutions, the user observes the surface of the roll and, when noticing the hot spot, removes it manually with the help of a scraper.

! 1 I

stickies add to the hot spot problem. Nowadays, on-line coating is often followed in connection with paper machines and the coating material (paste) needs to be dried before calendering. Sometimes the pasta gets damp, which also causes increasing hot spot problems. The coating of the rolls may also be damaged by so-called ribbing, resulting in coating damage causing vibrations on the roll surface.

5

The surface of the roll also wears out during use, which increases surface roughness and reduces the quality of the paper, requiring the roll to be sanded and replaced with a replacement roll. For example, thermo rolls used in prior art calendars wear coarser, requiring an increase in the line load of the calender, which in turn takes up 10 calibers, and / or increases the calendering temperature, which saves on calibres and also increases energy consumption. The roll may also wear unevenly, causing the paper profile to vary and the roll to be sanded and replaced with a replacement roll.

For example, in a two-nip calendar with one deflection compensated and one 15 thermal roller in each, two replacement rolls are needed all the time in stock, which is cost-effective. On the other hand, re-coating of coated rolls is very expensive, which makes it very expensive to get the coating destroyed, for example due to a hot spot.

20 As it is known that the condition of the rollers is mainly monitored manually by the user; 'j contamination, deterioration of condition, damage eg hot spots and the like; , 'van problems, and following the quality of the paper, several !. replacement rolls and coatings have had to be replaced, which is expensive. In addition, downtime due to cleaning and rehabilitation measures has increased costs.

The prior art relating to the invention may refer, for example, to FI patent applications 971488 and 941620, US patent application 5,394,653 and EP patent application 0 359 304. FI patent application 971488 discloses a roller belt sander and a method for controlling a belt sander , 30 for surface grinding of wheeled rolls. However, the device and method known in this application are intended to be used when the roll has already been removed from the machine 3 113975 and thus has the advantage of reducing the grinding time. FI patent application 941620 discloses a method and apparatus for reconditioning a roll of a paper machine roll, wherein the roll surface is periodically reconditioned without removing the roll. However, this arrangement does not include monitoring to determine the condition of the roller 5 and the solution disclosed therein comprises providing a roller scraper to be repaired with a separate grinding device which is placed on the actuators of the scraper and connected to the surface to be sanded by the scraper. This device enables the roller to be sanded in place.

10 U.S. Patent 5,394,653 and EP 0 359 304 describe traversing superfinishing devices for grinding rolls, but the disclosed devices do not include monitoring the condition of the roll.

It is an object of the invention to provide a method and a device by means of which the roller 15 can be kept in good condition in the paper machine at all times, thus maintaining the desired quality level of the paper.

It is a specific object of the invention to provide an arrangement that is continuous and takes place while driving and does not require shutdown of the roll refurbishment and / or cleaning; * 20 for you.

The method according to the invention is essentially characterized in that, during the production run of the papermaking machine and / or post-treatment device, the roll surface / coating is continuously measured and monitored for contamination, wear and coating damage by means of measuring units between control units. on the basis of guiding said traversing cleaning / grinding unit, the surface of the roll / pin, ···. blade is cleaned and / or grinded with said traversing cleaning / grinding unit so as to maintain the roll and maintain the paper quality level as desired. 30 grinding / grinding unit grinding pressures are controlled via the control unit based on the measurement results.

4, 113975

The device according to the invention, in turn, is essentially characterized in that the device consists of an assembly comprising measuring units for measuring and monitoring the surface / coating of the roll for contamination, wear and coating damage, cleaning of the surface / coating of the cleaning / grinding unit and / or based on the measurement results, and controlling the traverse cleaning / grinding unit of the control unit based on the measurement results received from the measurement units, that the device is continuously operable during the production run of the paper machine and / or finishing device and that the grinding pressure of the cleaning / grinding unit

10

According to the invention, certain parameters are measured, after which the grinding / cleaning device is controlled based on the measurement results and the cleaning / grinding of the roll is performed. According to the invention, the purity and condition of the roll are continuously measured on a line by a suitable measuring method. At the same time, the shape and the circularity of the roll can be measured, for example, with non-contact laser sensors. In addition, according to the invention, the control also takes into account, if desired, the paper thickness profile information and other possible measurement data describing the paper quality and the operation data of the various parts of the paper machine.

; The device according to the invention preferably consists of a traversing multifunctional head for cleaning / reconditioning the roll and a control unit. Multifunctional traver-> ·. * The sound bar is preferably a commercially available bar and the multifunction head preferably consists of a grinding unit, a vibration measuring unit touching the surface of the roll, and a measuring unit of the shape and circularity of the roll.

... 25 '. The device according to the invention can be sensed in the scraper holder and the measuring device detects surface damage and can, if desired, control the shape of the roll. As an accessory for the device of the invention, a traversing superfinishing device, such as that described in the aforementioned U.S. Patent No. 5,394,653 and EP-A-0 359 304, may be used.

5, 113975

According to the invention, the same grinding unit is used for cleaning and grinding the roll surface. When the roll is only dirty, it is sanded with a small grinding pressure, whereby the surface of the roll is not substantially worn but dirt is removed. If the coating has a deformation, the grinding pressure is automatically varied higher at the roll packing point and reduced at the thinner position, thereby correcting the deformation. Likewise, the grinding pressure can be varied during one roll revolution, whereby the circular error can be corrected. By means of the device according to the invention it is possible to remove material, for example at a hot spot, whereby its progress can be stopped. The grinding unit grinding parameters are automatically selected based on the measured signals obtained from the paper-10 machine control system. In addition to the grinding pressure, the traverse speed and the relative speed between the abrasive element and the surface to be sanded can be adjusted.

As is known, the beams of the papermaking machines have deformations affecting the roll grinding device 15. In connection with the device according to the invention, measuring devices can be provided for measuring the shape of the roll and any possible hangings, and correcting them by software so that even if the beam is curved or hanging, possibly oblique or curved, the roll is grinded. • * 'For example, a laser beam can be used to bend the beam first order; '20 to measure.

In the method of the invention, the linearity errors of the traverse beam and the beam. deflection etc. is compensated by software. For example, a laser beam parallel to the calendar roll can be used as a reference line, whereby the mechanical structures do not have to be massive and excessively precise. The system according to the invention thus compensates for its own faults based on control.

.. The rollers are not always completely round, which causes problems. According to the invention, for example, one or more accelerometers can be attached to the shaft of the doctor blade, so that the shape of the roll can be measured very precisely.

6, 113975

According to the invention, wetting and chemicals can be used to enhance the removal and grinding of dirt. Excess moisture is removed by blowing, suction, or a combination of these.

According to the invention, maintaining the roll condition achieves the desired paper quality at all times without the need for downtime to replace the roll, reducing the need for replacement rolls and increasing the coating life of the roll. If desired, the invention can also be used during shutdown without removing the roll.

According to a preferred embodiment of the invention, the surface of the roll is measured by a laser sensor and the thickness data of the paper is taken in both the machine and the cross machine direction, and the same device with the measuring devices is used for cleaning and grinding the roll. The apparatus replaces the abrasive tape with a cleaning belt, for example, a very fine diamond or other specially developed cleaning belt, and grinds the surface of the roll with low pressure, whereby the roll length does not actually change when it is found that the roll is in need of cleaning. If you notice that the roll has a defect in the cross machine direction, that is in the longitudinal direction of the machine, sharpen the roll so that you can * * “correct the defect. If "angularity" of the roll is detected, the grinding is varied during one rotation of I * • f 20, thereby correcting roll defects within one rotation.

The device according to the invention is used while driving.

! When, in the arrangement according to the invention, for example, a hot spot has been detected by measurement, it is located by means of measuring devices and the material abrasive head removes 25 substances only from the hot spot of the roll to the surface of the roll. The device according to the invention is continuous and the measurement and cleaning / grinding are performed while driving. This is very important because hot spots come in well; I fast and have only a few minutes to act.

Thus, the arrangement according to the invention is intelligent, it investigates and operates on the basis of its research results, and the defects, vibrations and others of the roll can be corrected. In accordance with the invention, the roll 7113975 is maintained in good condition at all times, so that the quality level of the paper is maintained at all times. The invention is well suited for use with polymer rolls and thermal rolls. When using the device according to the invention, the desired quality is always achieved with a minimum of work and the possible downtime due to roll cleaning / refurbishment 5 is considerably less than with the prior art stiffeners.

In the following, the invention will be described with reference to the figures in the accompanying drawings, the details of which, however, are not intended to be limited in any way.

10

Figure 1 schematically illustrates an embodiment of a device according to the invention.

Figure IA schematically illustrates another embodiment of step 15A of the embodiment example of Figure 1.

Fig. 2 schematically shows another embodiment of a device according to the invention.

Figure 1 schematically illustrates a device 20 of the invention, preferably a '* * superfinishing device, tracked along a roll 10. It has a cleaning roll 24 which; , 'Cleaning and grinding is carried out and a piezo-crystal or magnetostrictive e.g. an actuator 23 based on phenol material. The device 20 is fixed to the conductors 13,14 in the pattern bar 11, to which the formula 12 is also attached.

25

The device 20 also comprises a measuring device 30 for measuring and monitoring the roll surface for contamination, wear and coating damage. Preferably, the device 20 also comprises a measuring device 31 for measuring the directness of the conductor beams 13, 14 and other structures of the measuring device 20 and for transmitting the measurement result thereof to the control system 3 3 of the device 20 '30, which compensates for any misalignments.

Measuring devices 32 for measuring the shape of the roll are also tracked in connection with the device 20, the information obtained from which is also transmitted to the control system 33 of the device, which also provides information on measurements made in other parts of the paper machine. A cleaning / grinding belt 22 passes through a cleaning roller 24 which is arranged to pass through a guide and drive rollers 25,27. The device 20 according to the invention is connected to a cleaning roll 24 having an active actuator 23 based on e.g. a piezocrystalline or magnetostrictive material (terfenol) or the like, which is electrically controlled.

The beam 11 of the scraper 12 shown in the figure is one embodiment of the attachment, but the device according to the invention can be attached to another device, to the roll or can be followed by its own attachment beam.

Figure IA schematically illustrates another embodiment of paragraph 1A of Figure 1, in which the cleaning roller 24 is replaced by a cleaning shoe 34. In other respects, the structure of the device 15 is as shown in Figure 1.

In the device 20 according to one embodiment of the invention shown in Fig. 2, the abrasive / cleaning belt 41 is connected between two rollers 42, 43 as an endless belt and is controlled by an actuator 23 made with piezo-crystal or magnetostrictive material. In other respects, the embodiment illustrated in FIG. 2 is the same as that shown in FIG. 1, and the like is denoted by the same reference numerals.

In the exemplary embodiments shown in the figure, the device 20 according to the invention is fixed to the bar 11 on the bar 11 for the conductors 13 and has, for example, rails 14 for the device 20. The pressure adjustment is effected, for example, by a pneumatic cylinder 29 and the device 20 may be traverse. The device 20 undergoes surface finishing / cleaning / restoration as is known in the art according to the invention, based on the information provided by the measuring units 30, 31, 32 of the device 20 under the control of the control unit 30 33. The control unit 33 also receives information on required items from the paper machine / finishing control system 34.

9 113975

According to the invention, the device 20 is used for cleaning and grinding the surface of the roll 10. If the roll is only dirty, sand it with a small grinding pressure so that the roll surface does not wear out but dirt is removed. If there is a deformation in the coating, the grinding pressure is automatically varied higher at the thicker point of the roll 10 and reduced at the thinner point, thereby correcting the deformation. Likewise, the grinding pressure can be varied during one revolution of the roll 10, whereby the circular misalignment can be corrected. By means of the device according to the invention, the material can be removed at, for example, a hot spot and the grinding parameters are automatically selected on the basis of measured signals received from the paper machine control system. In addition to the grinding pressure, the traverse speed and the relative speed between the sanding element and the surface to be sanded can be adjusted.

A variety of abrasive methods and measurement methods known per se, e.g. accelerometers, laser-15 gauges and linear sensors, can be used in connection with the device of the invention.

The invention has been described above with reference only to some preferred embodiments thereof, the details of which, however, are not to be construed as being narrowly limited.

: 20, Many modifications and variations are possible within the scope of the inventive idea defined in the following claims.

Claims (18)

113975 A method for reconditioning a roll (10) of a papermaking machine or paper finishing device, wherein the roll surface / coating is cleaned and / or sanded by a 5 traverse cleaning / grinding unit, characterized in that the roll (10) is continuously rolled during the production run of the papermaking machine and / or the coating is measured and monitored for contamination, wear, and coating damage through the measurement units (30, 31, 32) and the control results of the measurement results transmitted from the measurement units (30, 31, 32) to the control unit (33) to clean and / or grind the roll / coating with said traverse cleaning / grinding unit (24, 34, 41; 23, 29) such that the roller (10) is maintained at all times and the paper quality level is maintained desired and in the method, the grinding pressure of the cleaning / grinding unit is controlled by by . 15 Process according to Claim 1, characterized in that the cleaning and grinding are carried out in the same unit. <*; The method according to claim 1 or 2, characterized in that in the method *, · '20, the roll (10) is measured and reconditioned by an assembly of devices (20). * · * · I * * * · Method according to one of claims 1 to 3, characterized in that the method of measuring the shape and circularity of the roll and measuring the roll and circularity errors detected in the measurement * · * are corrected by said apparatus assembly (20). Method according to one of Claims 1 to 4, characterized in that the control of the assembly (20) used for measuring, cleaning / reconditioning the roll (10) takes into account the measurement data obtained from the control system (34) of the paper machine / paper finisher. (MM 113975 Method according to one of Claims 1 to 5, characterized in that the method measures and compensates for errors in the position of the roll, e.g., the suspension and the frame structures of the roll (10) and the assembly (20). Method according to one of Claims 1 to 6, characterized in that the method comprises cleaning and / or repairing a calender roll. Process according to one of Claims 1 to 7, characterized in that the process comprises cleaning and grinding a polymer coated roll. 10 Method according to one of Claims 1 to 8, characterized in that the method comprises cleaning and / or grinding a polymer-coated roller of the calender and detecting and eliminating hot spot coating defects. Apparatus for rebuilding a roll of a paper machine and / or paper finishing device, comprising a means (20) for traversing and / or grinding the roll, characterized in that the device (20) consists of an assembly (20) comprising measuring units (30, 31, 32). ) for measuring and monitoring roll surface / coating • for contamination, wear and coating damage, cleaning / grinding unit 20 (24, 34, 41; 23, 29) for cleaning and / or grinding roll surface / * based on measurement results and control unit (33) to control the traversing cleaning »· * * / grinding unit based on the * $ '· measurement results received from the measuring units (30, 31, 32), that the device is continuous during the production run of the paper machine and / or the finishing unit 25 and that the grinding pressure controlled by the units of measurement units (30, 31, 32)! based on measurement results. »» »I * · Ί Device according to Claim 10, characterized in that the cleaning unit · · * i * / grinding unit is the same unit. v .: 30 Device according to claim 10 or 11, characterized in that the 113975 measuring unit comprises measuring means (30) for measuring the cleanliness and condition of the roll surface. Device according to one of Claims 10 to 12, characterized in that the 5 measuring unit comprises a unit for measuring the shape and circularity of the roll (32). Device according to one of Claims 10 to 13, characterized in that the measuring unit comprises a measuring device (31) for measuring the position of the roll and the position of the roll (10) and the assembly (20). 10 Device according to one of Claims 10 to 13, characterized in that the device assembly (20) comprises means for adjusting the grinding parameters. Device according to one of Claims 10 to 15, characterized in that the device 15 is adapted for use in the repair of a calender roll. Device according to one of Claims 10 to 16, characterized in that the device is adapted for use in the regeneration of a polymer-coated roll of a calender. . · 20 Device according to one of Claims 10 to 17, characterized in that the device is adapted to be used in the rehabilitation of a calender polymer-coated roll for the detection and elimination of hot spot * * "· coating defects. · * Ei »·» »• · •» * I »113975