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Title:
ARRANGEMENT FOR FIBER WEB PRODUCTION OR HANDLING LINE
Document Type and Number:
WIPO Patent Application WO/2009/071749
Kind Code:
A2
Abstract:
The present invention relates to an apparatus arrangement (10) for fibrous web production and treatment line comprising a frame arrangement (30) and machine components (20, 40, 45, 55, 60, 67) for treating the fibrous web and arranged in connection with the frame arrangement (20, 40, 45, 55, 60, 67). At least two machine components (60, 67) of the apparatus arrangement are supported by the frame arrangement (30) or a part thereof connecting them and comprising a part (32) consisting of a material (32) having greater dampening properties than monolithic steel.

Inventors:
JORKAMA MARKO (FI)
AAKERLUND KENNETH (FI)
HAAG JORMA (FI)
LINJA JUHA (FI)
MUSSALO MIKA (FI)
PULLINEN HANNU (FI)
KAKKONEN PASI (FI)
KOJO MARKKU (FI)
Application Number:
PCT/FI2008/050712
Publication Date:
June 11, 2009
Filing Date:
December 04, 2008
Export Citation:
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Assignee:
METSO PAPER INC (FI)
JORKAMA MARKO (FI)
AAKERLUND KENNETH (FI)
HAAG JORMA (FI)
LINJA JUHA (FI)
MUSSALO MIKA (FI)
PULLINEN HANNU (FI)
KAKKONEN PASI (FI)
KOJO MARKKU (FI)
International Classes:
B65H35/02; B65H18/20; D21G1/00; D21G1/02
Domestic Patent References:
WO2005080676A22005-09-01
WO2006084955A12006-08-17
Foreign References:
EP0972880A22000-01-19
US3944150A1976-03-16
US4691488A1987-09-08
EP1726547A12006-11-29
Attorney, Agent or Firm:
GENIP OY (Kotka, FI)
Download PDF:
Claims:

We claim

1. An apparatus arrangement (10) for a production and treatment line of a fibrous web comprising a frame arrangement (30) with machine components (20, 40, 45, 55, 60, 67) designed for treatment of the fibrous web arranged in connection with the frame arrangement, characterized in that at least two machine components (60, 67) of the apparatus arrangement are supported by the frame arrangement (30) or a part thereof connecting them, the frame arrangement comprising a part (32) consisting of a material having greater dampening properties than monolithic steel.

2. An apparatus arrangement according to claim 1 , characterized in that in the apparatus arrangement (10) at least one excitation-producing part (40) and at least one delicate part (60) are supported by the said frame arrangement or a part thereof comprising a part (32) made of material having better dampening properties than monolithic steel.

3. An apparatus arrangement according to claim 1 or 2, characterized in that the frame arrangement of the apparatus arrangement or a part thereof comprising a part (32) having better dampening properties than monolithic steel is larger in mass than a part made of steel according to conventional engineering dimensioning principles used for monolithic steel.

4. An apparatus arrangement according to claim 3, characterized in that the apparatus arrangement additionally comprises an additional mass part (32) for improving the vibration situation.

5. An apparatus arrangement according to any of the previous claims, characterized in that the apparatus arrangement is a slitter-winder and the at least one excitation- producing machine component (40) supported by the said part (32) is in connection to the roll to be wound on the winding part and that the delicate part supported by the said part is one of the following: a slitting part (20), web spreader (67), divider of the component webs (68).

6. An apparatus arrangement (10) for a fibrous web production or treatment line according to any of the previous claims, characterized in that the apparatus arrangement is a slitter-winder for a fibrous web and that the delicate part of the slitter-

winder is the slitting part (20) comprising the slitting blades (61) with their support structures.

7. An apparatus arrangement (10) for a fibrous web production or treatment line according to any of the previous claims, characterized in that the apparatus arrangement is a slitter-winder for a fibrous web and that the said excitation-producing part of the slitter-winder is a press roll (40).

8. An apparatus arrangement (10) for a fibrous web production or treatment line according to any of the previous claims, characterized in that the machine components supported by the said apparatus arrangement or a part thereof (32) comprise fastening means having vibration dampening properties chosen specifically for the machine component through which the machine components are fastened to the said frame arrangement or a part thereof (32).

9. An apparatus arrangement (10) for a fibrous web production or treatment line according to any of the previous claims, characterized in that the slitting part (20), the web spreader (67) and/or the divider of component webs (68) is supported via the elastic material (70) by the said frame arrangement or its part (32).

10. An apparatus arrangement (10) for a fibrous web production or treatment line according to any of the previous claims, characterized in that the said material having better dampening properties than monolithic steel is reinforced concrete.

Description:

ARRANGEMENT FOR FIBER WEB PRODUCTION OR HANDLING LINE

[001] The present invention relates to an apparatus arrangement for a production and treatment line of a fibrous web according to the preamble of claim 1.

[002] The production and treatment line of a fibrous web comprises an assembly formed by a number of apparatuses arranged consecutively in the process line. A typical production and treatment line comprises a head box, a wire section and a press section as well as a subsequent drying section and a reel-up. The production and treatment line can further comprise, for example, a calender. The production and treatment line also comprises at least one slitter- winder for forming customer rolls as well as a roll packaging apparatus.

[003] Due to increased efficiency aims the requirements on the apparatuses of the production and treatment line are very high. Due to the increase of machine speeds the effect of vibration properties, among others,, is increasing. Typically steel is used in the production of the apparatuses and in some cases another metal is used. However, a relatively low vibration dampening is one of the properties of steel. The machine components (e.g. support drum, press roll, core lock) taking part in the treatment of the web in connection with the apparatuses (e.g. slitter-winder) are thus subjected to impulses from other machine components.

[004] A solution in which the machine components are arranged in two separate frame parts is known from prior art. Thus, vibration in machine direction is often caused as the machine is running. The attempts to minimize this include stiffening the frame by connecting the separate frame parts by means of a steel strut extending in machine direction, whereby the combination of two frame parts is more rigid than one frame part. A disadvantage with such a strut is, however, that it can transmit vibrations from one frame part to another. Additionally it is often difficult to arrange such a strut in machine direction and it increases material consumption.

[005] US 4691488 discloses use of concrete as a filler of the hollow steel frame of the machine component. In the solution disclosed here the concrete acts as an internal vibration dampener in the frame. The solution disclosed here is very slow to produce in practise, as the frame itself must first be manufactured, then the frame must be filled with concrete and finally there is a delay while the concrete sets.

[006] A calender, a so-called multi-roll calender, as the calender of the type shown in the solution is called, is disclosed in US 6578473 as an example of an apparatus in the production and treatment line of fibrous material. Such a calender is formed by two support frames located at a distance from each other. The calender also comprises an upper and a lower roll supported by, correspondingly, upper and lower bearings, the bearings being supported by the said support frames so that the upper bearings are solidly supported and the lower bearings are supported so as to be vertically adjustable. The multi-roll calender also comprises a number of superimposed intermediate rolls arranged between the upper and lower rolls. Together with the upper and lower rolls the intermediate rolls form calender nips when they have been brought into nip connection with each other. Each intermediate roll is connected to the support frame by a special lever arm having a driving means attached in connection therewith. Such a solution allows compensation of the mass of the intermediate rolls, whereby the nip load is constant.

[007] In prior art calenders a massive support structure having considerable rigidity is needed in addition to the support frame, making the apparatus a very large unit. Typically the support frame is a support structure made of steel that also dampens vibration relatively ineffectively, thus further increasing the need to make the support structure very massive.

[008] Publication FU 17902 discloses a foundation solution for a paper or board machine or the like for supporting the component or apparatus of the paper or board machine. The foundation solution comprises a frame in connection with which the members, such as rolls, of the component/apparatus are supported. The frame of the component/apparatus is supported by the building through a solid, massive bottom so that the bottom is supported to the foundation of the building by a movable connection. However, this publication

only concentrates on the foundation solution of the component/apparatus, in which solution the problems relating to disadvantageous or unknown ground conditions in a sufficiently stable support can be eliminated or at least minimized both dynamically and statically.

[009] Of the apparatus arrangements of the production and treatment line of a fibrous web the slitter-winder is one that simultaneously performs a delicate process, such as slitting and spreading of the component webs with the slitting part and, on the other hand, performs a process containing objects producing impulses, such as support drums, core locks and so on. The delicate assembly carrying out the delicate process is at the slitter-winder formed by the slitting blades with their support structures and the spreading roll with its support beam located before the rolling of the component webs as well as other guiding of the web, especially the guide roll located before the cutting.

[0010] Thereby a holistic control of vibrations is of especial importance. The slitting itself is especially problematic, as the exact contact surface of the blade pair forming the slitting apparatus should not be subjected to vibrations for the slitting to succeed.

[0011] The aim of the invention is to produce an apparatus arrangement for a production or treatment line according to the preamble of claim 1 , in which the apparatus arrangement is provided with better vibration properties, among others, than in prior art apparatuses of a production or treatment line.

[0012] The aim is achieved by means of a production and/or treatment line of a fibrous web mainly by having at least two machine components of the apparatus arrangement supported by a frame arrangement or a part thereof connecting them comprising a part consisting of a material having greater dampening properties than monolithic steel.

[0013] This arrangement creates the effect that the vibration and/or impulses of the various machine components of the apparatus arrangement are not transmitted to other machine components in a disturbing degree.

[0014] In the apparatus arrangement, preferably at least one part producing impulses and at least one delicate part are supported by the said frame arrangement or a part thereof comprising a part consisting of material having better dampening properties than monolithic steel. Thus, the delicate part is essentially separated from the excitation-producing part in a vibration-technical sense.

[0015] The effect of the invention can further be enhanced by optimizing the support of each machine component to the frame arrangement as far as the rigidity of the dampening is concerned e.g. so that the machine components supported by the frame comprise fastening means having vibration dampening properties chosen for each machine component, through which fastening means the machine components are attached to the frame.

[0016] According to one embodiment the apparatus arrangement is a slitter- winder and the at least one excitation-producing machine component supported by the said part is in connection to the roll to be wound on the rolling part and the delicate part supported by the said part is at least one of the following: a slitting part, web spreader, divider of the component webs. Preferably the slitting part is supported through an elastic material to the said frame arrangement or its part.

[0017] According to one embodiment of the invention the invention relates also to a calender arrangement in the production line of a fibrous web, the calender being a multi-roll calender comprising a stack of rolls comprising rolls than can be arranged in nip connection with each other, of which rolls at least the intermediate rolls are supported by means of roll-specific locking arrangements to a support frame arranged to be fastened to a separate support structure, the support frame being arranged to be fastened to the building foundation.

[0018] According to one embodiment the support frame is arranged to be fastened directly to the building foundation. Preferably the support frame is arranged to be fastened to a concrete foundation.

[0019] According to one embodiment the support frame comprises a fastening part via which the support frame is detachably fastenable to the concrete foundation.

[0020] According to another embodiment the calender arrangement comprises an upper roll at the first end of the roll stack and a lower roll in the second end, the upper roll being supported by the support frame. According to yet another embodiment the calender arrangement comprises an upper roll at the first end of the roll stack and a lower roll in the second end, the upper roll being supported by the building foundation.

[0021] Preferably the said support frame replaces a part of the casting mould into which the concrete is cast.

[0022] According to one embodiment the functional machine components supportable directly to the building foundations comprise the intermediate rolls of the calender and their support and adjustment structures.

[0023] In the concept of this application the term "functional machine components" means such machine components of the calender arrangement and their support and adjustment structures associated with the treatment and/or guiding of the fibrous web in the calender arrangement.

[0024] The other additional characterizing features of the invention will become apparent from the appended claims.

[0025] In the context of this application, the term "support drum" means, in addition to the actual roll also other types of carrier apparatuses, such as a combination of rolls and a belt or belts.

[0026] A number of advantages are achieved by means of the invention. By means of the invention it is possible to isolate machine components having a high tendency to vibrate from other machine components of the apparatus arrangement. Using a material having better dampening properties than monolithic steel the mass of the frame arrangement can be increased in a simple way especially for improving vibration behaviour, even to exceed the requirements of strength only. Additionally the support of each machine component to the frame arrangement can be optimized for the rigidity of the dampening.

[0027] In the following the invention and its operation are described by reference to the appended schematic drawings, in which figure 1 schematically illustrates an apparatus arrangement for a production and treatment line of a fibrous web according to one embodiment in a side view, figure 2 illustrates the apparatus arrangement according to figure 1 in a top view, figure 3 is an exemplary illustration of the frequency response of a machine component, figure 4 illustrates a calender arrangement according to an embodiment of the invention, figure 5 illustrates a calender arrangement according to another embodiment of the invention, figure 6 illustrates a calender arrangement according to yet another embodiment of the invention, figure 7 illustrates the driving apparatus of the intermediate rolls according to the invention, figure 8 illustrates the parts of the driving apparatus of figure 7 in more detail, figure 9 illustrates the support of the upper and/or lower roll of the calender arrangement according to an embodiment of the invention, figure 10 illustrates a calender arrangement according to yet another embodiment of the invention, figure 11 illustrates the replacement apparatus of the lower roll of the calender arrangement in a side view, figure 12 is the replacement apparatus of figure 11 in a front view, figure 13 illustrates in front view the lifting table structure designed to be used in connection with the calender arrangement, and figure 14 is a top view of the lifting table structure of figure 13.

[0028] Even though the invention is in the following described with reference to figures 1 and 2 by reference to a slitter-winder having a support drum winder, the invention is especially well suitable for use with a center- wound slitter- winder.

[0029] Figures 1 and 2 are schematic illustrations of an apparatus arrangement 10 of a production and treatment line for a fibrous web according to an embodiment of the invention, the apparatus arrangement here being a slitter- winder. Among the apparatus arrangements of the production and treatment line of the fibrous web the slitter-winder especially is one in which is simultaneously carried out a delicate process, the longitudinal slitting being carried out by the slitting part, and on the other hand a process dealing with large masses, the winding of the web component rolls 56. Figure 1 shows the slitter-winder from the side and figure 2 shows the slitter-winder from the top, the treatment side (TS) and driving side (DS) sectioned at different levels. The slitter-winder comprises an un-winding part 15, a slitting part 20 and a winding part 25 that in this embodiment is a carrier reel roller provided with a press roll 40 and support drums 45. The machine roll 16 previously prepared at the unwinding part 15 is un-wound and guided by guide rolls 65 through the slitting part 20 to the winding part 25. The press roll 40 is supported by the press roll beam 43 fixed at its ends to guides 50 essentially perpendicularly to the longitudinal axis of the support drums. Correspondingly, when the winding part 25 is in use, the so-called core lock apparatus 55 is also fastened to guides 50 essentially perpendicularly to the longitudinal axis of the carrier rolls. Figure 1 shows the slitting blades 61 with their support structures 60 at the slitter-winder as an example of a delicate assembly 66, as well as the divider 68 of component webs with its support beam.

[0030] The slitter-winder comprises a frame arrangement 430 comprising a part consisting of a material having dampening properties higher than a structure made of monolithic steel. In this embodiment the part is a part 32 made of steel reinforced concrete. In figure 1 the un-winding part 15 and the slitting part 20 of the slitter-winder 10, the press roll beam 43 as well as core locks 55 are supported by the part 32 consisting of steel reinforced concrete and thus the above-mentioned machine components of the slitter-winder 10 are connected to each other through a part formed of reinforced concrete. The steel reinforced concrete increases the mass of the frame structure by an essential amount and improves the vibration dampening. This provides an essential reduction of the effect of vibration between the machine components fastened to the frame structure by means of both the relatively large mass and the increase of the

dampening. Thus the effect of the possible vibration of each machine component to another machine component is effectively dampened.

[0031] The part 32 consisting of steel reinforced concrete comprises fastening zones 33 into which the machine components are fastened by, for example with regard to guide rolls 65, their bearing housings. The fastening zones are preferably metallic attachment surfaces arranged during the casting of the reinforced concrete. Preferably the fastening method is such as to allow adjusting the alignment of the machine components subsequent to installation. In this embodiment the slitting part 20 and the actuators spreading or separating the web, such as rolls 67, are additionally isolated by means of an elastic spacer 70 from the part 32 of the frame arrangement consisting of reinforced concrete, thus isolating the slitting part even more efficiently from the vibrations of other machine components. Thereby the delicate part is isolated from vibrations and the part producing impulses, such as the guide roll guiding the web to the spreading roll, is installed to the frame part in a way dampening the vibrations. The effects of the vibrations and their control can further be improved by having the machine components essentially comprise fastening means provided with vibration dampening properties chosen specifically for each machine component, the fastening means attaching the machine components to the frame of reinforced concrete. In some cases the rolls, for example, can be fastened directly to the concrete frame.

[0032] The frame arrangement 30 according to the embodiment of the invention shown in figure 1 also comprises a part 34 consisting of steel to which the support drums 45 of the winding part 25 are supported in this embodiment.

Thus, in this way especially the support drums 45 are efficiently vibrational^ isolated from the slitting part 20, press roll beam 43 and the core locks 55 and thus any vibration excitations are not transmitted to other machine components of the slitter-winder in a detrimental degree. According to one embodiment machine components having a strong tendency to vibrate are isolated from the other machine components of the apparatus arrangement by supporting at least two machine components of the apparatus arrangement to a frame arrangement or a part thereof comprising a part made of steel reinforced concrete connecting them. Thus, the frame is essentially wholly made of steel

reinforced concrete, operating simultaneously both as a main support structure and the vibration isolator between the machine components.

[0033] In some cases it will be preferable to divide the part 34 of the frame to which the carrier rolls are supported into separate parts 34', 34", whereby the impulses from the rolls are not transmitted to each other so well. Thus, one of the parts 34', 34" can according to the invention be a frame made of steel reinforced concrete.

[0034] The effect of the invention can further be enhanced by optimizing the support of each machine component to the frame arrangement for the rigidity of the dampening e.g. in the way shown in the embodiment of figures 1 and 2 so that at the fastening to the frame the slitting part 20 is isolated by means of an elastic spacer 70 from the part 32 of the frame arrangement. The vibration behaviour of the whole apparatus arrangement can be better controlled when using vibration-dampening reinforced concrete as the frame or at least as a part thereof for first isolating the various machine components from each other and then to additionally provide the fastening of each machine component with the desired properties. Each fastening of a machine component to the frame can be separately optimized for the rigidity of the dampening. In practice this can, for example, mean that the rigidity of the support to the frame for the vibration- sensitive cross-beam so that the relation between the most significant excitation frequency and the lowest nominal bending frequency is chosen such that the transmissivity of the vibration from the frame to the beam is sufficiently low or as desired.

[0035] Figure 2 additionally exemplifies how the part 32 consisting of material, such as steel reinforced concrete, with greater vibration dampening properties than monolithic steel ends up more massive than the prior art part made of steel. In some applications the part 32 can comprise a support structure part for the apparatus arrangement and an additional mass part for the apparatus arrangement, preferably as a unit structure, however. By support structure part we mean the part of the frame arrangement necessary for the strength reasons, i.e. the structure defined by the dimensioning principles of traditional engineering. In practice this means that with the arrangement according to the invention the mass of the frame arrangement can be simply increased

especially for improving vibration behaviour, even stronger than the situation allows on the basis of strength reasons only, i.e. the mass of the frame exceeds that defined by the dimensioning principles of traditional engineering and the mass has been so increased that the vibration conditions have essentially improved.

[0036] Figure 3 simulates the vibration of a sensitive machine component, such as a lower blade beam, on the impulse from another machine component with both a conventional arrangement (solid line) and an arrangement according to the invention (dotted line). These machine components are connected to each other through the frame. The change from conventional steel frame structure to the reinforced concrete structure is modelled so that in a reinforced concrete arrangement the relative dampening of the frame is tenfold, the nominal frequency drops from 10 Hz to 5 Hz and the mass increases to double that of the conventional frame structure. When the impulse of the excitation-producing machine component remains the same in the case according to the invention (dotted line) the amplitudes of the vibration are reduced in resonances over 50% compared to the arrangement according to a conventional solution (solid line). In the figure the horizontal axis represents the frequency of the vibration in Hertz and the vertical axis represents the movement per force unit. The lowest peak represents the nominal frequency of the frame, the second lowest is that of the sensitive machine component and the third one that of the impulse-giving machine component. The amplitudes of all resonance peaks drop, especially the peak of the sensitive machine component on the frequency of about 15 Hz.

[0037] Figure 4 illustrates schematically the calender arrangement 110 of an embodiment of the invention. The calender arrangement comprises a stack of rolls 115.1, 115.2, 120.1, 120.2 that can be brought into nip connection with each other. The stack consists of the so-called upper roll 120.1 and the lower roll 120.2 and their intermediate rolls 115.1 , 115.2. This type of calender is a so-called multi-roll calender. Typically the upper and lower roll are so-called variable crown rolls and the intermediate rolls are alternately arranged soft- surfaced 115.1 and hard-surfaced 115.2 rolls. In the embodiment shown in figure 4 the stack is essentially vertical, but arranging the stack in a certain angle is also possible.

[0038] The calender arrangement also comprises a support frame 130. In the embodiment of figure 4 the intermediate rolls 115.1 , 115.2 are supported by the support frame 130 via lever arms 125, i.e. roll-specific attachment means. Each lever arm is rotatably supported by the support frame 130 via bearings 135. Each roll is supported to the lever arm on the end opposite to the bearing with a driving means 140 arranged at the other end, by means of which the position of the roll in the arrangement can be effected on as well as its effect on the treatment of the fibrous web by means of adjusting the nip load.

[0039] The calender arrangement further comprises so-called flyer rolls 116 in connection with each intermediate roll. The fibrous web W is directed to run in the calender arrangement through consecutive nips N via the flyer roll 116 so that the web coverage on the upper rolls 120.1 , 120.2 and intermediate rolls 115.1 , 115.2 is minimized.

[0040] In the embodiment of figure 4 the upper roll 120.1 is solidly supported and the lower roll 120.2 is adjustably supported, guided by guide 145 and supported by the load cylinder 150. The position of the lower roll 120.2 in relation to the support frame (e.g. quick opening of the nips) by means of the load cylinder 145 and it can also be used for effecting the nip load of the rolls in a way known as such. The upper roll 120.1 is in this embodiment also supported by the concrete frame 160 via the base plate. The actual detailed method of anchoring the machine components to the concrete cast can vary case by case.

[0041] In the embodiment shown in figure 4 the support frame 130 of the calender arrangement 110 is arranged to be fastened directly to the building foundation 160 being a concrete foundation. In this embodiment the support frame is provided with gripping means 165 on at least one side thereof, the gripping means staying in the cast concrete.

[0042] The calender arrangement is installed so that the ready support frame is positioned on its desired place and the concrete is cast. As the concrete sets, it locks the support frame in it is position. The support frame acts partially as a part of the cast mould, replacing the actual mould for a certain portion. The cast fixing the support frame can be the actual casting of the foundation or the

support frame can be fastened to the concrete foundation as a post-casting. The other parts of the calender arrangement are installed to the support frame after the concrete has essentially set.

[0043] In the embodiment of figure 4 also the support structure 146 of the guide 145 belonging to the support of the lower roll is fastened to the concrete cast of the building foundation 160, i.e. the concrete foundation of the building.

[0044] Figure 5 shows another embodiment. It mainly corresponds with the embodiment shown in figure 4 and thus corresponding reference numbering is used in figure 5. The following disclosure mainly describes the differences between the embodiment of figure 5 and the embodiment of figure 4. In the embodiment of figure 5 the support frame 130 comprises a fastening part 131 via which the support frame 130 is detachably fastenable to the concrete foundation. Thus only the fastening part 31 is needed when the building foundation 160 is cast and the fastening of the support frame by means of, for example, bolt connection 132 can be made later. The profile of the fastening part can be, for example, U-shaped, whereby the cast can extend inside it to the fastening surface 133.

[0045] The embodiment of figure 5 also shows that the upper roll 120.1 can also be fastened to the support frame 130.

[0046] Figure 6 shows a calender arrangement according to a third embodiment of the invention. Here, the support frame 130 can be made to comprise the space 134, i.e. it can be formed wholly or totally hollow so that the concrete cast of the frame structure 160 can extend to essentially inside the support frame.

[0047] Thus the calender arrangement can be made very rigid with good vibration dampening properties. Additionally the amount of steel needed is considerably lower than in prior art solutions.

[0048] Figures 7 and 8 illustrate the driving apparatus 170 of the intermediate rolls 115.1 , 115.2 according to the invention. The driving apparatus comprises a first toothed belt sprocket 172 connected to the intermediate roll 115.1 , 115.2

and a belt loop to the tensioning wheel 174 and a second toothed belt sprocket 176 connected to the driving motor 178. The driving apparatus 170 is supported by the support structures of the intermediate roll (not shown).

[0049] In the driving apparatus of intermediate roll 115.1 , 115.2 there is a number of parallel toothed belts 180 instead of one wide belt. Preferably two toothed belts are arranged side by side so that therebetween is formed a space, gap 182, having a width equal to about the height of the tooth of the belt. Thus the width of the sprocket extends to the width of two toothed belts and preferably they are one of unit construction, whereby the structure of the tooth grooves is identical on the area of both belts. A gap 182 having a width approximately equal to the height of the tooth is arranged centrally in the longitudinal direction of sprockets 172, 176, preferably by machining, the depth of the gap being at least as deep as the tooth gap, preferably slightly deeper. The groove 182 acts as an exit route for the air when the tooth 181 of the toothed belt intrudes into the gap 173 when the apparatus is running. One of the belt sprockets has flanges 184 on the outside preventing the belts 180 from being displaced. The tensioner wheel 174 is provided with an extension or protrusion 184 corresponding to the width of the said gap 182 to the circumference of the shroud of the wheel, essentially centrally in its longitudinal direction so that in use the extension 184 is positioned between the belts 180. The extension 184 keeps the belts 184 separated and thus it keeps the gap 182 of the sprockets open for air removal.

[0050] Thus, an exit route for air remains on both sides of the toothed belt. The outlet area of the air expelled from the tooth groove increases considerably in relation to the total width of the toothed belt. The velocity of the air flow also decreases considerably, thus also reducing noise. In the invention it is possible to provide the actual sprockets 172, 176 with an extension keeping the toothed belts separated, but it is technically easier to provide the tensioning wheel 174 with a flange, as it is a smooth wheel.

[0051] Figure 5 shows the support of the upper and/or lower roll 120.1 , 120.2 of the calender arrangement 110 according to the invention. Preferably the support of the upper roll comprises a cradle 190 welded solidly to the support frame 130 and made of cast steel, to which the bearings 192 of the upper roll

120.1 are fastened. The support of the lower roll comprises a structure corresponding to the said cradle 190 that can also be solidly connected to the support frame 130, but it can alternatively also be detachably connected by a bolt fastening.

[0052] The attachment surfaces 195 of the bearing are conical surfaces allowing making the attachment preferably even self-locking, with due regard to workplace safety, by suitably dimensioning the angle. Thereby the angle α is < 8°. The new construction allows a faster and safer way of changing the upper and lower rolls of the calender arrangement, a simpler construction due to the reduced number of components in the construction and a stronger construction in the upper roll position as well as a faster and more accurate installation (positioning both across the web and vertically).

[0053] Figure 10 also shows another embodiment of a calender according to the invention by means of which the calender arrangement can be driven in both multi-roll and partial nip modes. The solution of figure 10 comprises a subframe 1100 into which a lower roll 120.2' is attached, the roll preferably being a bending-compensated roll, as well as a first 115.1' and a second intermediate roll 115.2'. The nip angle β of the lower roll 120.2' and the first and second intermediate roll 115.1', 115.2' preferably deviates 14 - 22° from the vertical.

[0054] The subframe 1100 is supported by the support frame 130 of the calender or by the building foundation supporting it as is shown in figure 10 with e.g. a slide guide 145 or a lever mechanism allowing a guided vertical movement of the subframe. The other intermediate rolls 115.1 , 115.2 are supported by the support frame 130 of the calender arrangement.

[0055] The first 115.1' and the second 115.2 intermediate roll are supported by the subframe 1100 by a slide guide or a lever mechanism. The lower roll 120.2' is fixedly supported by the subframe 1100 and the roll is preferably mantel- loaded variable crown roll. The output roll 116.1 is supported by another intermediate roll 115.2 and thus it moves with the roll. The output roll 116.2 is supported by the subframe 1100.

[0056] The arrangement of figure 10 can be driven e.g. so that grades requiring more surface treatment, such as glossy grades, the whole roll set is used during calendering and all nips are closed, whereby the web W is directed to the nip between the upper roll 120.1 and the uppermost intermediate roll 115.1. When the nips are closed, the intermediate rolls 115.1', 115.2" fastened to the subframe 1100 move towards the lower roll 120.2' and the lowest nips are closed. The next nips in the roll set are closed by means of a load cylinder 150, collecting the intermediate rolls with it and closing the whole roll set as it rises. During closing of the roll set the intermediate rolls can be lightened typically about 95 % of their own weight. The dimensioning of the intermediate roll 115.2' takes into consideration the bending forces caused by the asymmetric load. The rolls of similar type (rolls with hard and soft surface) in the arrangement can be mutually interchangeable.

[0057] The quick opening of the roll set can be made so that the line load is first released and the nips open in a familiar way from the up downwards. The intermediate rolls 115.1', 115.2' can be moved away from the lower roll 120.1 in the subframe as soon as a gap is formed between the upper intermediate roll 115.2' supported by the subframe and the lowest intermediate roll 115.1 supported by the support frame 130 as the subframe moves downwards. Also the shrouds of the upper and lower rolls (variable crown rolls) can be moved to opposite directions during quick opening.

[0058] For example, when calendering matte grades in the lower part of the roll set, the partial nip drive is carried out by displacing the first intermediate roll

115.1' supported by the subframe and the second intermediate roll 115.2' towards the lower roll 120.2', whereby the nips are closed. Thereby the web W is directed to the apparatus to between the upper intermediate roll 115.2' supported by the subframe and the lowest intermediate roll 115.1 supported by the support frame 130, shown with a dotted line in figure 10. The first intermediate roll 115.1' and the second intermediate roll are provided with their own driving means (not shown).

[0059] The line load is formed by means of the shroud of the lower roll 120.2". The angle β deviating from vertical between the rolls 120.2', 115.1', 115.2' of the subframe helps to avoid the zero load areas of the bearings and small line

loads of 5-30 N/m can be calendered. During quick opening the intermediate rolls 115.1', 115.2' can be moved away from the lower roll. The shroud 120.2' can additionally be moved away from the direction of the load.

[0060] By means of the solution the support of the lower roll 120.2' of the calender arrangement or the intermediate rolls 115.1', 115.2' does not have to be changed into different positions for avoiding zero load when changing the calendering from glossy grades to matte grades. Thus the change of grade with the calender is faster as mechanical positioning is eliminated. Due to the shroud-ioaded bending-compensated roll the adjustment of line load is more accurate than the adjustment of the line load of a roll with solid shroud moving on a guide mechanism. This will also make it possible to exchange the lowermost bending-compensated roll directly with a roof crane without hooks or a separate exchange cradle.

[0061] Figures 11 and 12 show the exchanging apparatus 1200 of the lower roll 120.1 of the calender arrangement in front and side view. The exchanging apparatus 1200 is arranged outside the frame of the calender arrangement 110 to run along a surface machined on the bottom plate 1210 of the frame. This solution avoids using separate rails, their installation and use of loose pieces when the web runs through the cellar. Additionally, with a twin-frame machine level model the same exchanging apparatus can be used for changing both lower rolls. The exchanging apparatus is directed to come in contact with the lower roll and the lower roll is supported to the exchanging apparatus 1200 and removed from the calender. The roll 120.2 is moved away from the calender supported by the exchanging apparatus to a distance at which it can be lifted away from the exchanging apparatus 1200 by means of the crane 1220.

[0062] Figure 13 shows a lifting table structure 1300 for assisting in exchanging the rolls of the calender arrangement as a front view and in figure 14 as a top view. The lifting table structure 1300 shown in the figures is a three-part construction comprising a central part 1310, i.e. the central corridor 1310 with end baskets 1320 at the ends thereof. The arrangement also comprises vertical frame parts 1330 to which the end baskets 1320 are arranged by means of guide means 1340, such as guide rails. The arrangement also comprises a lifting machinery (not shown) for moving the lifting table construction and/or the

end baskets up and down along the guide rail. The end baskets 1320 are provided with a locking device 1350 by means of which the central part 1310 can be detached and locked to the end baskets 1320, whereby the central part 1310 can be left or positioned on the floor level and the end baskets 1320 can be driven up and down on the end area of the roll set of the calender arrangement. Thereby there is no need to lift the roll over the central portion of the lifting table at any stage and yet the lifting table can be used in monitoring the condition of the roll set in normal operation by locking the central part to the end baskets.

[0063] It should be noted that only a few of the most preferable embodiments are disclosed above. Thus, it is obvious that the invention is not limited to the above-mentioned embodiments but it can be applied in many ways within the scope defined by the appended claims. It should specially be noted that the invention can also be applied at the reel-up of the fibrous web machine where a corresponding problem can be encountered in certain situations. The features disclosed in connection with various embodiments can also be used in connection with other embodiments within the inventive scope and/or different assemblies can be combined from the disclosed features, should it be desired and should it be technically feasible.

[0064] The solution according to the invention can also be applied to a number of paper grades of which the most important are discussed in the following.

[0065] Paper and board are available in a wide variety of types and can be divided according to basis weight in two grades: papers with a single ply and a basis weight of 25-300 g/m 2 and boards manufactured in multi-ply technology and having a basis weight of 150-600 m/m 2 . It should be noted that the borderline between paper and board is flexible since board grades with lightest basis weights are lighter than the heaviest paper grades. Generally speaking, paper is used for printing and board for packaging.

[0066] The subsequent descriptions are examples of values presently applied for fibrous webs, and there may be considerable fluctuations from the disclosed values.

[0067] Mechanical-pulp based, i. e. wood-containing printing papers include newsprint, uncoated magazine and coated magazine paper.

[0068] Newsprint is composed either completely of mechanical pulp or may contain some bleached softwood pulp (0-15%) and/or recycled fibber to replace some of the mechanical pulp. General values for newsprint can probably be regarded as follows: basis weight 40-48.8 g/m 2 , ash content (SCAN-P 5: 63) 0-

20%, PPS S10 roughness (SCAN-P 76-95) 3.0-4. 5 urn, Bendtsen roughness

(SCAN-P21 : 67) 100-200 ml/min, density 600-750 kg/m 3 , brightness (ISO 2470: 1999) 57-63%, and opacity (ISO 2470: 1998) 90-96%.

[0069] Uncoated magazine paper (SC = supercalendered) usually contains mechanical pulp to 50-70%, bleached softwood pulp to 10-25%, and fillers to 15-30%. Typical values for calendered SC paper (containing e. g. SC-C, SCB, and SC-A/A+) include basis weight 40-60 g/m 2 , ash content (SCAN-P 5: 63) 0- 35%, Hunter gloss (ISO/DIS 8254/1) < 20-50%, PPS slO roughness (SCAN-P 76: 95) 1.0-2. 5 urn, density 700-1250 kg/m 3 , brightness (ISO 2470: 1999) 62- 70%, and opacity (ISO 2470: 1998) 90-95%.

[0070] Coated magazine paper (LWC = light weight coated) contains mechanical pulp to 40-60%, bleached softwood pulp to 25-40%, and fillers and coaters to 20-35%. General values for LWC paper can be regarded as follows: basis weight 40-70 g/m 2 , Hunter gloss 50-65%, PPS S10 roughness 0.8-1. 5 urn (offset) and 0.6-1. 0 urn (roto), density 1100-1250 kg/m 3 , brightness 70- 75%, and opacity 89-94%.

[0071] General values for MFC paper (machine finished coated) can be regarded as follows: basis weight 50-70 g/m 2 , Hunter gloss 25-70%, PPS S10 roughness 2.2-2. 8 urn, density 900-950 kg/m 3 , brightness 70-75%, and opacity 91- 95%.

[0072] General values for FCO paper (film coated offset) can be regarded as follows: basis weight 40-70 g/m 2 , Hunter gloss 45-55%, PPS S10 roughness 1.5-2. 0 urn, density 1000-1050 kg/m 3 , brightness 70-75%, and opacity 91-95%.

[0073] General values for MWC paper (medium weight coated) can be regarded as follows: basis weight 70-90 g/m 2 , Hunter gloss 65-75%, PPS S10 roughness 0.6-1. 0 urn, density 1150-1250 kg/m 3 , brightness 70-75%, and opacity 89- 94%.

[0074] HWC (heavy weight coated) has a basis weight of 100-135 g/m 2 and can be coated even more than twice.

[0075] Pulp-produced, woodfree printing papers or fine papers include uncoated and coated pulp-based printing papers, in which the portion of mechanical pulp is less than 10%.

[0076] Uncoated pulp-based printing papers (WFU) contain bleached birchwood pulp to 55-80%, bleached softwood pulp to 0-30%, and fillers to 10- 30%. The values with WFU are highly unstable : basis weight 50-90 9/m 2 (up to 240 g/m 2 ), Bendtsen roughness 250-400 ml/min, brightness 86-92%, and opacity 83-98%.

[0077] In coated pulp-based printing papers (WFC), the amounts of coating vary widely in accordance with requirements and intended application. The following are typical values for once-and twice-coated, pulp-based printing paper: once-coated basis weight 90 g/m 2 , Hunter gloss 65-80%, PPS S10 roughness 0.75-2. 2 urn, brightness 80-88%, and opacity 91-94%, and twice- coated basis weight 130 g/m 2 , Hunter gloss 70-80%, PPS S10 roughness 0.65- 0. 95 μm, brightness 83-90%, and opacity 95-97%.

[0078] Release papers have a basis weight within the range of 25-150 g/m 2 .

[0079] Other papers include e. g. sackkraft papers, tissues, and wallpaper bases.

[0080] Board making makes use of chemical pulp, mechanical pulp and/or recycled pulp. Boards can be divided e. g. in the following main groups according to applications thereof. - Corrugated board, comprising a liner and a fluting.

- Boxboards, used for making boxes, cases. Boxboards include e. g. liquid packaging boards (FBB = folding boxboard, WLC = white-lined chipboard, SBS = solid bleached sulphite).

- Graphic boards, used for making e. g. cards, files, folders, cases, covers, etc. - Wallpaper bases.