WO2008065240A1

WO2008065240A1 - Method and device in a fibre-web reeler

Info

Publication number: WO2008065240A1
Application number: PCT/FI2007/050598
Authority: WO
Inventors: Risto MÄKINEN; Jari Tiitta; Marko Tiilikainen; Matti Kemppainen; Tatu PITKÄNEN
Original assignee: Metso Paper, Inc.
Priority date: 2006-11-30
Filing date: 2007-11-08
Publication date: 2008-06-05
Also published as: CN101541655A; EP2097344B1; CA2669155A1; EP2097344A1; FI20065764A0; FI119633B; FI20065764A; CN101541655B

Abstract

The invention relates to a method in a reeler of a fibre web, in which method, the web (W) is reeled around a reeling shaft (21) into a web roll (22) by means of a reeling nip (RN) between a reeling drum (10) and the forming web roll (22). The structure of the web roll (22) is affected by a roll nip (N) provided between the forming web roll (22) and a separate roll (40) adjustable of its bow during reeling. The invention also relates to a device in the reeler of a fibre web, which reeler comprises a reeling drum (10) for providing a reeling nip (RN) with the forming web roll (22). The device comprises a separate roll (40) adjustable of its bow for proving a roll nip (N) with the forming web roll (22) for affecting the structure of the web roll (22).

Description

Method and device in a fibre-web reeler

The invention relates to a method in a reeler of a fibre web according to the preamble of claim 1.

The invention also relates to a device in a reeler of a fibre web according to the preamble of claim 5.

The present invention relates to a method and a device in reeling a fibre web, such as a paper or board web, into a machine reel i.e. a reel corresponding to the full- width of the web. The width of machine reels is usually 2.0-10.0 m and the diameter 2.0-4.5 m naturally depending on the dimensioning of the paper or board ma- chine.

As known from prior art, the machine reelers of a paper or board web are usually located at the end of the manufacturing line of the paper or board web and with them the completed fibre web is reeled into a machine roll around a reeling shaft i.e. a so-called spool. This is often followed by on-line or off-line finishing apparatuses by means of which customer rolls according to customer requirements are manufactured of the paper or board web. In reeling-up taking place in machine reelers, a reeling drum arranged in a nip contact with the reeling shaft and the web roll forming around it is usually utilised. A problem in connection with the ma- chine reelers of a fibre web is that, when reeling fibre-web types having poor air permeability at high speeds, air is carried along inside the machine roll from a nip between the forming web roll and the reeling drum. Air inside the roll, again, decreases the friction between the web layers in the roll, which can cause different reeling problems, such as reel falling, telescoping, edge displacement, flagging, wrinkles etc. With fibre-web types having poor air permeability, air can exit the roll / air can be removed from the roll principally only through the ends of the roll, which is problematic, because due to the deflections of the rolls and the loading of the reeling drum and the machine roll done from the ends of the reeling shaft, the nip pressure profile is usually smiling i.e. the pressure is greater in the end areas of the roll than in the middle of the roll.

As known from prior art, one has tried to minimise above-described problems by making onto the surface of the reeling drum a low groove which rises towards the edges and guides the air in the machine roll towards the edges of the roll. A disadvantage of this arrangement is that the surface of the machine roll is not always even but can include rises and valleys, whereby, when a groove and a valley encounter, the nip pressure can be lower and thus at such a point a lot more air can penetrate the machine roll compared with other points. Furthermore, removing air from the edges is difficult as the nip load in the edge areas is higher than in the middle.

DE patent publication 199 27 897 describes a roll adjustable in its bow used as a contact or transfer roll. A contact roll is e.g. a roll used in reeling, which is partly covered by the web and which is in pressure contact with the forming web roll and which prevents air from penetrating into the forming web roll especially dur- ing high reeling speeds. It is possible to us higher pressure in the middle of the contact roll compared to the pressure used at the ends in order to press the air travelling with the web to the sides.

US patent 6,604,703 shows a reeling cylinder using a reeling cylinder adjustable on its bow. In addition to the reeling cylinder a separate pressure roll can be used, which is pressed against the forming web roll before the reeling nip is opened.

The separate press roll forms a roll nip after the reeling nip with the forming web roll and the aim of the roll nip is to prevent air from penetrating into the web roll when the reeling nip is opened. EP patent publication 369 977 shows a reeler using a deflection compensated reeling shaft and a deflection compensated reeling cylinder. The idea of the deflection compensated reeling cylinder is to keep the nip pressure as even as possible in the reeling nip.

A roll adjustable in its bow is described in FI patent applications 20031384 and 20041287 which describe a roll for paper, board or finishing machines in which the outer shell of the roll is supported from its ends to the frame structures of the machine by means of an adjustable bearing so that both the direction and amount of the deflection of the outer shell can be controlled i.e. the bow of the outer shell of the roll can be adjusted for compensating the tightness differences between the edge and middle areas of the web. The roll consists of two parts supported to each other in the middle area of the roll, an inner tube and an outer shell. The nominal stiffness of the production material of the inner tube of the roll can be substan- tially greater than the nominal stiffness of the production material of the outer shell of the roll. A roll of this type with two shells, supported from the middle, adjustable of its bow, of equal diameter, a so-called T roll has been used e.g. in calenders as a fly roll.

An object of the present invention is to provide a method and a device in reeling a fibre web in which the above-described disadvantages and problems of arrangements known from prior art have been eliminated or at least minimised.

A special object of the invention is thus to create a novel type of an arrangement by means of which the structure of the web roll can be affected.

To achieve the above-mentioned objects and those which come out later, a method according to the invention is mainly characterised by what is presented in the characterising part of claim 1. Again, a device according to the invention is mainly characterised by what is presented in the characterising part of claim 5.

In the method and the device in reeling a fibre web according to the invention, it has been realised to affect the structure of the web roll by a separate roll adjustable of its bow, by means of which is provided peripherical force affecting the forming web roll from the surface of the roll as surface draw different from the thoughts related to the reeling of machine rolls known from prior art in which peripherical force has been typically provided by means of central force.

According to an embodiment of the invention, in reeling a fibre web for affecting the structure of the web roll, in connection with the reeler there is a separate roll adjustable of its bow which is used substantially for the whole time of reeling and by means of which a roll nip is provided at the forming web roll. The bow of the roll is advantageously adjusted so that the pressure in the roll nip between the roll and the forming web roll does not increase, advantageously decreases towards the ends of the reel, whereby e.g. it is easier to remove air from the structure of the web roll towards lower pressure. Then, the nip pressure profile of the roll nip between the separate roll adjustable on its bow and the forming web roll is substan- tially even or lowers towards the edge areas (a sad profile).

According to an advantageous embodiment of the invention, the roll nip between the separate roll adjustable of its bow and the forming web roll is advantageously located after the reeling nip advantageously as close as possible before the start of the next web layer. In this embodiment, also the reeling drum can be a roll adjustable of its bow.

In the roll adjustable of its bow utilised in the method and the device according to the invention, the direction of the bow is advantageously adjustable, whereby against the rotation direction of the forming web roll is provided a plough effect which facilitates the removal of air from the reel, because air exits the reel in its natural travel direction.

In connection with the invention, the bow and the direction of the bow of the roll adjustable of its bow are adjustable during run, whereby also the tightness profile of the forthcoming web can be affected.

By means of the equal-diameter roll adjustable of its bow utilised in connection with the invention, which thus advantageously substantially corresponds the type of a roll described in FI specifications 20031384 and 20041287 of its structure, is achieved as an advantage compared with crowned rolls according to prior art that, when using a roll according to the invention, no speed and thus tightness differences of the cross direction of the web caused by diameter difference, e.g. further loosening of loose edges, will be created.

By means of the invention is provided minimising the total amount of air in reeling, because in the reeling nip between the reeling drum and the forming web roll the access of air into the web roll is prevented and in the roll nip between the separate roll adjustable of its bow and the web roll to be formed the air possibly remaining in connection with the web roll is removed.

The roll adjustable of its bow utilised in connection with the method and the device according to the invention is advantageously covered with a suitable soft cover, such as polyurethane or rubber, whereby the roll adapts to irregularities possibly on the surface of the machine reel, the air permeance of the web being reeled being low.

According to an advantageous additional characteristic of the invention, onto the surface of the roll is made a low groove rising towards the edges for further en- hancement of air removal. The spline of the groove can be multiplex. According to an advantageous additional characteristic of the invention, the roll is provided with an electric drive for adapting the speed to the machine reel speed.

The invention is applicable in connection with reelers utilised in reeling different machine reels, particularly advantageously the invention is applicable to be utilised in connection with reelers marketed by the applicant with product names Op- tiReel and OptiReelPlus and equivalent types. The advantages achieved with the invention become particularly evident when reeling fibre-web types having low air permeability.

In connection with the invention advantageously, the nip force of the roll nip is adjusted by measuring the nip force from the ends of the roll with power sensors or by implementing to the roll the measuring of nip pressure profile based on an electro-magnetic foil or other pressure- or power-sensitive sensor or sensor strip directly from the nip. Furthermore, the nip profile can be measured and the deflection and bow radius of the roll can be adjusted.

The invention will now be described in more detail with reference to the figures of the accompanying drawing, to the details of which the invention is, however, by no means intended to be narrowly confined.

Figure 1 schematically shows an embodiment of a roll adjustable of its bow to be used in connection with the invention.

Figs. 2-5 schematically show an embodiment of the invention in which the invention is applied in a reeler which utilises a stationary secondary position.

Fig. 1 schematically shows an embodiment of a roll 40 adjustable of its bow to be utilised in connection with the invention, in which an outer shell 42 of the roll is supported from its ends to the frame structure of the machine by means of an adjustable bearing 45 so that the direction and amount of the deflection of the outer shell can be controlled i.e. the bow of the outer shell of the roll can be adjusted for levelling the tightness differences between the edge and middle areas of the web. The roll 40 consists of two parts supported to each other in the middle area of the roll, an inner tube 41 and the outer shell 42. The roll 40 illustrated in the figure is coated with a suitable soft cover 43, such as polyurethane or rubber. Onto the surface of the roll 40, it is possible to make a low groove (not shown) rising towards the ends of the roll 40. Advantageously, the roll 40 is provided with an electric drive (not shown). The roll 40 adjustable of its bow utilised in connection with the invention is advantageously of the type described in FI specifications 20031384 and 20041287, but also other corresponding types of rolls adjustable of their bow are applicable to be used in connection with the invention.

Next in Figs. 2-5, Fig. 2 schematically shows the reeling stage just before transferring the reeling from the secondary position to the primary position i.e. the change stage; Fig. 3 schematically shows the reeling stage in which there is a completed reel in the secondary position and the reeling transfers to the primary position; Fig. 4 schematically shows the reeling stage in which a completed reel is delivered from the secondary position and the reeling from the primary position is transferred to the secondary position; and Fig. 5 schematically shows the reeling stage in which reeling carriages are transferred to receive the next reeling shaft, the reeling continuing in the secondary position. In the figures, the same designations are used of parts corresponding each other. In the embodiment shown in Figs. 2-5 according to the invention, the structure of a web roll 20 is affected with a roll nip provided with a roll adjustable of its bow. The roll adjustable of its bow is a separate roll 40 arranged in a nip contact with the web roll by means of which is provided a roll nip with the web roll in addition to a reeling nip. According to an embodiment of the invention, into connection with the web roll is arranged in addition to the separate roll adjustable of its bow a reeling drum which is adjustable of its bow. In the situation according to Fig. 2, the web W is reeled into the web roll 20 in the stationary secondary reeling position. A secondary drive 25 is connected to a reeling shaft 24. In the vicinity of the secondary position, there is a surface binding device 30. During reeling, the reeling drum 10 is in a nip contact with the forming web roll 20. The drive of the reeling drum 10 has been referred to with reference number 11, and the direction of movement of the reeling drum 10 with reference number SlO. In the situation described in the figure, the reeling is about to be changed around a next reeling shaft 21 which is provided with a primary drive 26 and positioned in reeling carriages (not shown in the figure). The reeling shaft 21 has been brought to a nip contact with the reeling drum 10 and the change is performed by means of a water-changing device 16 by cutting the web W and e.g. by means of an air-blowing device 17 by guiding the web W around the reeling shaft 21. The roll 40 adjustable of its bow forms during the change the roll nip assisting the change and the bow of the roll 40 is adjusted during reeling so that the nip pressure profile of the nip between the roll 40 and the forming web roll 22 is substantially even or lowering towards the edge areas, whereby the removal of air towards the lower pressure is easier. The spreader roll of the web W is designated with reference number 18. In the embodiment shown in the figure, the reeling carriages move on reeling rails 15. Dashed lines in the figure also show the reel- ing shafts of forthcoming reels with reference number 21' and their direction of movement in the transfer stage with reference arrows S21 '.

In the situation according to Fig. 3, the reeling has transferred around the new reeling shaft 21 and the forming web roll has been designated with reference number 22. The roll 40 adjustable of its bow forms a roll nip with the forming web roll 22 which nip removes air from the web roll. Furthermore, the direction of the bow of the roll 40 is advantageously adjustable, whereby against the rotation direction of the forming web roll 22 is provided a plough effect which facilitates the removal of air from the reel, because air exits the reel in its natural travel di- rection. As is evident from the figure, the roll nip N between the roll 40 adjustable of its bow and the forming web roll 22 is located after the reeling nip RN advan- tageously as close as possible before the start of the next web layer, still typically in the area of the upper part of the bow of the circle of the web roll 22. The surface of the completed web roll 20 situated in the secondary position is bound with the surface binding device 30 for preventing the loosening of reeling. The surface binding device 30 has been transferred by a manner shown with arrow S30 from a stand-by position to a surface binding position (Fig. 2). In this stage, the reeling drum 10 and the forming new web roll 22 are transferred by a manner shown by arrows S21 and SlO apart from the web roll 20 in the secondary position.

In the situation shown in Fig. 4, the completed web roll 20' is transferred away from the secondary position. This transfer is shown with arrows S20. The surface binding device 30 has been detached from the web reel 30 and, in this stage, the forming web roll 22 is started to be transferred together with the reeling drum 10 from the primary position in a manner shown by arrows S21 and SlO towards the secondary reeling position and, simultaneously, the roll 40 adjustable of its bow moves along the web roll 22 further forming the roll nip. The forthcoming position of the forming web roll 22 and the reeling drum 10 in the secondary position is shown with dashed lines.

According to what is shown in Fig. 5, when the web roll in reeling has been transferred to the secondary position, the web roll being reeled is designated again with reference number 20. The reeling carriages are returned, as shown with arrow SV, towards the next reeling shaft 21 which is transferred on the reeling rails towards the carriages for starting the reeling of the next web reel around the new reeling shaft 21, when the reel in the secondary position has grown to a desired diameter. The roll 40 adjustable of its bow is in the stand-by position and transfers into connection with the new reeling shaft 21 as the reeling changes onto the new reeling shaft for reeling the next web reel. The invention was described above only referring to some of its advantageous embodiments, to the details of which the invention is, however, by no means intended to be narrowly confined.

Claims

1. A method in reeling a fibre web, where the web (W) is reeled around a reeling shaft (21) into a web roll (22) by means of a reeling nip (RN) between a reel- ing drum (10) and the forming web roll (22), characterised in that, the structure of the web roll (22) is affected by forming a roll nip (N) between the web roll (22) and a separate roll (40) adjustable of its bow and by adjusting the bow of the separate roll (40) adjustable of its bow and/or the direction of the bow during reeling.

2. A method according to claim 1, characterised in that, the bow of the separate roll (40) adjustable in its bow is adjusted so that the nip pressure of the roll nip (N) between the separate roll (40) adjustable of its bow and the forming web roll (22) does not increase, advantageously decreases towards the ends of the web roll.

3. A method according to claim 1 or 2, characterised in that, the direction of the bow of the roll (40) adjustable of its bow is adjusted so that a plough effect is provided against the rotation direction of the forming web roll (22).

4. A method according to any one of claims 1-3, characterised in that the nip load and/or force and/or nip profile prevailing in the roll nip (N) is measured by means of at least one pressure-sensitive measuring foil (50) which pressure-sensitive measuring foil (50) is installed into connection with the roll (40) adjustable of its bow.

5. A device in a reeler of a fibre web, which reeler comprises a reeling drum (10) for providing a reeling nip (RN) with a forming web roll (22), characterised in that the device comprises a separate roll (40) adjustable of its bow, which forms a roll nip (N) with the forming web roll (22), whereas the structure of the web roll (22) is affected by adjusting the direction and/or the amount of the bow of the separate roll (40) adjustable of its bow during reeling.

6. A device according to claim 5, characterised in that the separate roll (40) adjustable of its bow comprises an outer shell (42) which is supported from its ends to the frame structures of the reeler by means of an adjustable bearing (45).

7. A device according to any one of claims 5 or 6, characterised in that the separate roll (40) adjustable of its bow consists of two parts supported to each other in the middle area of the roll, an inner tube (41) and the outer shell (42).

8. A device according to any one of claims 5-7, characterised in that the roll (40) adjustable of its bow is covered with a soft cover (43).

9. A device according to any one of claims 5-8, characterised in that the separate roll (40) adjustable of its bow is provided with an electric drive.

10. A device according to any one of claims 5-9, characterised in that also the reeling drum (10) is a roll adjustable of its bow.

11. A device according to any one of claims 5-9, characterised in that the roll nip (N) between the separate roll (40) adjustable of its bow and the forming web roll (22) is located after the reeling nip (RN) advantageously as close as possible before the start of the next web layer.