FI121082B - Operator and arrangement for quick opening of the roll stack in a multiple-choice calendar - Google Patents

Description

Method and arrangement for quick opening of a roller in a multi-roll calender

The present invention relates to multi-roll calenders for fiber web machines and similar types of roll machines. The invention relates to a method according to the preamble of claim 1 and to an arrangement according to the preamble of claim 7 for quick opening of a roller in a multi-roll calender.

In calendars, a quick opening of the roller is required to prevent roll coating damage in a situation where a web break occurs. Because of the web break, paper mumps accumulate in the nip between the rolls, which can indicate soft roll coatings. During the web break, the nip between the rolls does not carry a fibrous web that carries heat and prevents excessive heating of the soft coating of the roll adjacent to the hot roll. Typically, calenders may have 15 hot-rolled surfaces, for example up to 250 ° C, adjacent to polymer-coated rolls, which may have an instantaneous temperature resistance of, for example, about 150 ° C. In the event of an outage, it is important to have the head roll as soon as possible and the line to pass through the closed nipples once the track has been cleaned of foreign objects.

20

In the event of a break in the track, the track nipples should be opened quickly so that the quick release starts quickly and the nip spacing quickly grows large enough. Thus, paper mules do not have time to become thick before they reach the nipples. Cutting the track and the subsequent cutting blast will cause the track to be such that it is not possible to know what kind of paper and hat is present in any area of the track during the quick opening time. Sufficient quick-release time has been known to be about 0.5 seconds, which is the time from the web break signal to the time the nipples have 5mm gaps. The said 5mm gap in the quick release has been required for paper calendars on supercalenders due to a marking problem.

The calendars of calendars of the type marketed by TwinLine under a multi-roll calender, such as a super calender or under the OptiLoad trademark, are conventionally comprised of a plurality of rolls arranged overlapping each other. The overlapping rolls are in nip contact with one another and the calendered paper or board web or the like is imaged to pass through the nip between the rolls.

5 The rollers are rotatably mounted on bearing housings which, for example in supercalenders, may in turn be mounted on base members slidably fitted with vertical guides in the calender body. The base portions are suspended through the retaining portions to the lifting spindles on the calender body, one of whose functions is therefore to act as a guide to hold the roller rollers in the correct position 10. The rollers are thus not rigidly attached to the calender body from their bearing housings, but allow the rolls to move vertically.

The masses of the roller bearing housings and auxiliary devices attached thereto, such as the output rollers, are quite large, which, for example in conventional supercalenders 15, had the significant disadvantage that these masses caused distortion of the line pressure distributions of the nipples. As a result, lightweight devices, supported on the base members of the rolls and on the spindle nuts on the lifting spindles, began to be used in multi-roll calenders, e.g. One such solution has been previously presented e.g. U.S. Patent 4,901,637. The use of lightening devices is also known from conventional machine calendars, in which, in particular, hydraulic lightening cylinders seek to eliminate the effect of point loads on roller bearing housings and auxiliaries described above.

EP 0 842 324 B1 discloses a method for quick opening of a calender, especially a super calender, and a hydraulic system for calender, especially a super calender. The object of this known method and hydraulic system 30 is to provide a method and system for controlling the roll nipples in the quick release in a controlled and desirable manner in the order desired, most preferably such that the quick release nipples open simultaneously.

The disadvantage of such a quick opening is its unnecessarily expensive technology.

5

In addition, the momentary free fall of the track has led to additional indirect costs due to the over-dimensioning of structures, such as the need for more massive foundations for impact caused by quick-opening. Rapid unlocking caused by a runtime malfunction may result in the foundation being subjected to approximately twice the load of the normal running load when applied with the quick-10 opening cylinders. In addition to the costs associated with the multi-roll calender body, the costs are also increased by the strength of the joints and levers used to support the rolls and possibly by the more expensive material choices. Further, the heavier sizing of the output rollers 15 has resulted in more expensive roll change tools and longer roll change times. In addition, due to the bolting of the rack with multiple bolts, the roll change time is long.

One problem with prior art 20-chamber opening cylinders for roller calendars for prior art multi-roll calenders has been the failure of the quick-release chamber oil drainage due to the oil-drain hose of the quick-opening chamber being located outside the relief cylinder structure. Therefore, said oil drain hose has been exposed to external factors. 25

The object of the present invention is to provide a new and inventive method for quick opening of a roller in a multi-roll calender that can solve or at least minimize the above-mentioned problems and shortcomings related to the quick-roll opening of a roller.

It is a further object of the present invention to provide a novel and inventive arrangement for rapid opening of a roller in a multi-roll calender that can solve or at least minimize the aforementioned problems and shortcomings associated with the quick-roll opening of a roller.

In order to achieve the foregoing and further objects, the method according to the invention is essentially characterized by what is stated in the characterizing part of claim 1 and the arrangement according to the invention is essentially characterized by what is stated in the characteristic part of claim 7.

According to the invention, quick opening of the roller by the basic cylinders of the multi-roll calender lightening devices and the roller loading cylinders without separate quick-release cylinders allows for more cost-effective solutions, but still the roller can be opened In 0.5 seconds.

The quick opening of the multi-roll calender track using the basic hydraulic cylinders of the lightening devices enables easier and thus less expensive layout, sub-procurement, assembly and commissioning of a multi-roll calender.

Other features and advantages of the present invention are set forth in the following description and the dependent claims.

In the following, the invention will be explained in more detail by way of exemplary embodiments with reference to the accompanying schematic drawings.

Figure 1 is a side elevational view of a multi-roll calender in which the method of the invention as well as stiffening is applied.

Figure 2 is a schematic partial sectional view of an alternative arrangement for moving and lowering the lower roll of a multi-roll calender.

Figure 3 illustrates, in principle, alternative ways of arranging a pivot nip of a multi-roll calender.

5

The quick opening of a multi roll roll calender such as the roll roll caliper, known as the Optiload trademark, which is implemented with only lightening and loading cylinders, i.e. without separate quick opening rolls, is described below.

10

Figure 1 illustrates a multi-roll calender 10 comprising a calender body 11 mounted on a roll 12 of a plurality of rolls. The roll 12 comprises a top roll 13, a lower roll 14, and a plurality of intermediate rolls 15-22 arranged superimposed between the top roll and the lower roll. that they are in 15 driving touches to each other. Figure 1 shows the roll 12 of the multi-roll calender in the running position. In the example shown in the figure, the paper or board web W is led through the spreading roller 133 and the take-out roller 134 to the top nipple N1 and further through the other nipples N2-N8 of the multi-roll calender and finally out of the bottom nip N9. Between nipples N1-N9, the paper or board web W is taken off the roll surface by the take-up rolls 154, 164, 20 174, 184, 194, 204, 214, 224. As shown in Figure 1, the output rollers are alternately located "outside" of the roller (output rollers 164, 184, 204, 224) and "inside" (output rollers 154, 174, 194, 214) of the calender body 11.

1 is a deflection compensated roll whose bearing housings 131 are directly and rigidly secured to the frame 11 of the deflection compensated top roll 13, . The upper roll 13 is a so-called. soft roller and is provided with a flexible polymer coating.

6

1, the lower roll 14 of the multi-roll calender is similarly a deflection compensated roll, the roll jacket of which is rotatably mounted on the roll shaft and which roll 14 is provided with internal loading devices for adjusting the roll jacket deflection as desired. In the embodiment of the figure, the shaft of the lower roller 14 is mounted on the bearing arms 141, 5 which are pivotally mounted by the pivots 145 to the multi-roll calender body 11. The lower rollers 143 are mounted between the vertical roller frame 11 and the load arms 144, . Fig. 2 shows an alternative way of moving and loading the lower roll 14 in the multi-roll calender 10, wherein second hydraulically driven lower lower cylinders 146 are mounted between the multi-roll calender body 11 and the lower roll 14 bearing housings 141 to move and load the lower roll 14 in the loading direction. The loading of the nipples N1-N9 of the roller 12 can thus be effected by means of the first lower cylinders 143 of Figure 1 and the first 15 lower cylinders 143 of the roller 12 can be opened as required; or alternatively the loading of the nipples N1-N9 of the roller 12 can be effected by means of the second lower cylinders 146 of Figure 2 and the second lower cylinders 146 can be opened from the roller 12 as needed. The same reference numerals as in FIG. 1 are used in the same or similar parts in FIG. 2. The loading means 20 of the rollers 12 may also be engaged by the loading devices inside the upper roll 13. Thanks to the deflection compensated lower roll 14, the line pressure profiles can be kept flat at the nipples N1 to N9 of the roll 12. In the example of the figure, the lower roll 14 is also provided with a polymer coating corresponding to the upper roll 13.

In Figure 1, the intermediate rolls 15-22 of the track 12 consist alternately of hard and soft surface rolls such that, except for the central nip N5 of the track 12, all other nips have a second roll hard surface and a nip forming roll with a soft surface roll. The middle nip N5 of the track 12 is the so-called nip. a pivoting nipple, each of which comprises a nip forming rolls having 30 soft surface rolls. Thus, since the top roller 13 of the track is a soft surface roll, the top intermediate roll 15 is a hard surface roll. Correspondingly, the second uppermost intermediate roll 16 is a soft surface roll with a resilient polymer coating and there is still another 7, i.e. the third top intermediate roll 17 a hard surface roll. As noted above, the rolls 18 and 19 forming the middle nip N5 are soft rolls with a resilient polymer coating, whereupon the lower roll 20 is again a hard surface roll. Secondly, the lowest intermediate roll 21 is a roll with a polymer coating 5 and the lowest intermediate roll 22 is a hard surface roll.

Fig. 3 is a schematic diagram showing alternative ways of arranging a pivoting nip of the multi-roll calender as mentioned above. In the roller 12 of the multi-roll calender, the pivot nipple may be located at different positions, as in Example 10 of Figure 3. Figure 3 shows a set of ten rolls 12 showing soft-surface rolls in dark circles and hard-surface rolls in outlined circles. In the left-hand track 12 of Fig. 3, the pivoting nip is the middle nip as in Fig. 1, i.e., using the designations of Fig. 1, nip N5; in the center track 12, the pivoting nip is the third lowest nip 15, i.e., using the notations of Figure 1, the nip N7; and in the right-hand track 12, the pivoting nip is the third highest nip, i.e. nip N3 using the designations of Figure 1. Correspondingly, the pivoting nipple may also be located at different positions on racks comprising, for example, six, eight or twelve rollers.

The multi-roll calender of Figure 1 has bearing housings 151, 161, 171, 181, 191, 201, 211, 221 mounted on arms 152, 162, 172, 182, 192, 202, 212, 222 of each of the intermediate rolls 15-22 of roll 12 articulated with axially-directional pivots 153, 163, 173, 183, 193, 203, 213 and 223 of the rolls of said multi-roll calender caliper 113. The arms 152, 162, 172, 182, 192, 202, 212 and 222 are provided with lightening cylinders 155, 165, 175 , 185, 195, 205, 215 and 225, which are hydraulic cylinders attached at one end to said intermediate roller arms 15-22 and opposite end to a multi-roll calender body 11. These lightening devices provide relief from the bearing housings of the intermediate rolls 15-22 and the auxiliaries mounted on the bearing housings. The required relief forces 30 are of different magnitudes on the different intermediate rolls 15-22, since, as has already been pointed out, the output rollers secured to the bearing housings of the intermediate rolls 15-22 are alternately inside and outside the nip plane relative to the multi-roll calender body 11 8. of different sizes.

In the case of a quick opening of the track, the track rolls 13-22 of the track are made to separate from each other 5 so that each of the nipples N1-N9 opens or at least the load on each nip is unloaded and the opening of each nip has begun.

In a multi-roll calender, a single roll 12 may have a plurality of soft-surface deflection-compensated rolls, whereby a hard-surface thermo roll may be provided between two such deflection-compensated rolls 10. In the quick release situation, deflection compensated rolls, such as those known under the SymRoll brand, are unloaded, i.e., their hydraulic pressures are lowered, resulting in a short delay, for example, about 0.15 seconds, after which the nipples at least 15

One roll of a multi roll calender may have up to three rolls similar to the OptiGloss brand, each of these '' part rolls '' having a hard surface thermo roll 20 between two flexible deflection compensated rolls. Thus, one to two cut-off blows may be provided in connection with each of said OptiGloss-type parts sets.

According to one embodiment of the invention, the roll 12 of the multi-roll calender 10 comprises at least one cutting device known per se, such as a cutting blade 230, 25, the position of which in Figure 1 is exemplified. According to another embodiment of the invention, the roll 12 of the multi-roll calender 10 comprises at least one cutting device, such as a cutting blade, for each part roll comprising two nips. According to other embodiments, it is preferable that the paper or board web W be cut in roll 12 of the multi-roll calender 10 by at least one cutting device 30 such as a cutting blade into pieces of up to three to five nips.

9

According to one embodiment of the invention, it is further advantageous for the roll 12 of the roll roll calender 10 of the multi-roll calender 10 to be blown by at least one known perforation blowing 231, the position of which in FIG. Thus, one cut-off blow 231 may be provided, for example, for each roll of three rolls, that is, two nipples.

According to the invention, it is preferred that the quick release of the roll 12 be initiated after the web break signal by releasing the load on the roll deflected top roll 13 10 and the deflection compensated lower roll 14 and, if present, the deflection rolls of each of the above partial rolls. That is, in the case of the bogie 12 of the figure, where a deflection compensated roll is used as the lower roller, the roll shell with "falling" down a certain distance. If the lower roller is not provided with loadable loading members, the lower roller lifting cylinder 143 is depressurized to produce a corresponding effect.

20

In the quick release, the lower roller 143 of the multi-roll calender; The movement of 146 may be the same speed as in a normal opening, i.e. about 25 mm / s, and the movement of the intermediate rolls 15-22 of the multi-roll calender is staggered so that the roll 12 is fan-open. The movements of the intermediate rollers can be adjusted so that a gap is formed in all nipples within 0.5 to 25 seconds. In the upper nipples, the gap between the rollers is smaller than at the lower end of the roller 12, but the upper nipples are in any case removed due to the web speed W. It should be noted that there is no need to form an equal gap between the rolls, i.e., the opening of the track nipples is not simultaneous, but the opening of the track 12 of Figure 1 starts from the top 30 nips N1 and continues as a successive event towards the bottom nip N9.

10

In the case where the track 12 has a plurality of part rolls overlapping, the opening of the track in each part track preferably starts from the top nip, continuing as a successive event towards the bottom nip of this track.

5 The opening distances need not be significant, as nowadays polymer rolls with improved marking time are used as soft rolls.

It is known that a sufficient quick opening time is considered to be about 0.5 seconds, which is the time from the web break signal to the time when the nipples have 5 mm gaps. 10 The said 5 mm slot for rapid opening was previously required due to the problem of marking on paper rolls of supercalenders. However, nowadays, the impact and heat resistance of polymer rolls has improved with the introduction of new coatings, so even a smaller gap can be allowed in the quick release.

Thus, in accordance with the invention, the quick-release time of 0.5 seconds for the quick release of the base rolls of the multi-roll calender roll is defined as the length of time for unloading the roll, such as deflection compensated rolls, and starting the nip slots. During this time, the risk of paper has been eliminated from the nipples by means of cutting devices such as cutting blades and blows such as cutting blowing and due to the speed of the web.

At current paper speeds of about 2000 m / min, track W moves about 5 meters in 0.5 seconds. In the event of an orbit, possibly several cutters located in the track will cut the track immediately after the orbital signal 25, which implies that in the quick-release time (about 0.5 seconds), the cut-off track W has passed at least some of the nips or even all of the N1-N9.

The paper wrapping around the roll is prevented by cutting blows, which may be provided in multiple ways to the roll 12, so that the length of the web 30 wrapping around the roll after the cutting blows is 5-10 m, which with typical roll diameters is about three turns around the roll. Binding to this extent does not cause thermal problems on the polymer surface as the package does not become 11 tight. The situations where roll packing has occurred are mostly due to defective track break control or the cutting of the track with the cutting blades has not worked as desired. With the known quick-opening made by separate quick-release cylinders, packing in these 5 cases could not have been prevented.

During the quick release according to the invention, which is realized without separate quick release cylinders, the paper W potentially damaging the coating is able to exit at least part of the nipples, namely web roller calendars operating at 1000 m / min (16.7 m / s) 10 depending on the cutting blade and of all nipples, and multi-roll calendars of 2000 m / min (33.3 m / s) for all nipples. The length of the track from the cutting steel to the last nip is about 15-20 m, depending on the size of the track and the number of tracks. Preferably, the track has at least one to two cutoff blows.

The invention has been described above by way of example with reference to the accompanying figures. However, the invention is not limited to the figures only, but various embodiments of the invention may vary within the scope of the invention as defined in the appended claims 20.

Claims (9)

A method for rapidly opening a roller in a multi-roll calender (10), wherein the calendering paper or board web (W) is introduced between two or more intermediate rolls tracked between a deflection compensated top roll 5 (13), a deflection compensated lower roll (14) and top and bottom rolls (13,14). (15-22) formed by calendering nipples (N1-N9), which rolls (13-22) are arranged as a roller (12) and wherein the calendars are supported by hydraulic relief cylinders (155-225) of said intermediate rollers (15-22). ) to relieve the nip load caused by the masses of the bearing housings (15Ι-221) and associated auxiliaries (154-224), and in the method of rapid opening of the roller (12), the hydraulic loading pressures of the roller deflection compensated rollers (13, 14) downwards, characterized in that the roller (12) comprises at least one cutting device such as a cutting blade (230), and the method comprises the following steps: to open the calendering nipples (N 1 to N9): - cutting the paper or board web (W) with at least one cutting device on the track (12) to at least one track of up to five nips with a track point on the track following about 15-20 m from the last nip; N9) retrograde relative to the direction of travel of the web, and the loading cylinders (155; 225; 225) of the lowering rollers (143; 146), which are conventional basic hydraulic cylinders without separate quick release cylinders, the relief pressure is fully or partially released. Method according to Claim 1, characterized in that the lower roll (14) of the roller is lowered by the lower cylinders (143; 146) of the multi-roll calender (10). A method according to claim 1, characterized in that the jacket of the lower roller (14) of the roller 30 is lowered by means of loading devices inside the lower roller so that the roller jacket of the lower roller substantially moves downwardly relative to the lower roller axis. Method according to one of Claims 1 to 3, characterized in that the paper or board web (W) is cut in the roller (12) by at least one cutting device such as a cutting blade (230) into pieces of up to four nips. Method according to one of Claims 1 to 3, characterized in that the paper or board web (W) is cut in the roller (12) by at least one cutting device such as a cutting blade (230) into pieces of up to three nips. Method according to one of Claims 1 to 5, characterized in that the piece of paper or board (W) to be cut is blown by at least one cut-off blow (231). An arrangement for rapid opening of a roller in a multi-roll calender (10), wherein the calenderable paper or board web (W) is inserted between two or more intermediate rolls 20 disposed between the deflection compensated top roll (13), deflection compensated lower roll (14) and top and bottom rolls (13,14). (15-22) formed by calendering nipples (N1-N9), which rolls (13-22) are arranged as a roller (12) and wherein the calendars are supported by hydraulic relief cylinders (155-225) of said intermediate rollers (15-22). ) for reducing the nip load caused by the masses of the bearing housings (151-221) and associated auxiliaries (154-224), and the arrangement for rapid opening of the roller (12) comprises hydraulic loading cylinders of deflection compensated rollers (13, 14) and a downwardly casing characterized in that the arrangement for rapid opening of the roller (12) comprises: - lightening cylinders (155-225) of the intermediate rollers (15-22) and loading cylinders 30 of the lower roller (14) rolls (143; 146) which are conventional basic hydraulic cylinders without separate quick-release cylinders, and - you blade (12) for cutting at least one paper or board web (W) of a cutting blade (230) such that a paper or board web (W) ), at a distance of about 15-20 m from the last nip (N9), following the track entry path in the track, with the paper or board web (W) truncated in the track (12) to at least one piece of up to five nips. Arrangement according to Claim 7, characterized in that the roll (12) 10 comprises one cutting device, such as a cutting blade (230), for each part roll comprising two nipples. Arrangement according to Claim 8, characterized in that the roll (12) comprises one cut-off blow (231) per part roll 15 comprising three rolls. 20 25 30