WO2008068382A1

WO2008068382A1 - Multirollcalender

Info

Publication number: WO2008068382A1
Application number: PCT/FI2007/050655
Authority: WO
Inventors: Hannu Pullinen; Juha Linja; Timo Lipponen; Erkki Leinonen
Original assignee: Metso Paper, Inc.
Priority date: 2006-12-07
Filing date: 2007-12-03
Publication date: 2008-06-12
Also published as: FI20065779A0; DE112007002862T5; FI20065779A; FI119154B

Abstract

The calender comprises a frame (R) and a roll stack (A) supported on the frame. The roll stack comprises a top roll (11) and a bottom roll (12) as well as intermediate rolls (21-26) supported by means of articulated arms on the frame. In the first operating state, some of the intermediate rolls (21-23) are supported by means of a pivot point (42a) of an articulated arm (42) on a first support member (100) detachably attached to the frame of the calender. The top roll (11) or the bottom roll (12) is additionally supported on the frame of the calender by means of a first detachable intermediate member (110). In the second operating state, the first support member (100) is replaced with a second support member (120) detachably attached to the frame of the calender in place of the first support member. The lowermost roll (220) of an upper roll stack (B) and the uppermost roll (230) of a lower roll stack or both are stationarily supported on the second support member (120), and an intermediate roll (21) or intermediate rolls formed at the second support member is/are supported by means of pivot points (41a) of the articulated arms (41) on the second support member (120). The first intermediate member (110) is removed, the top roll (11) or the bottom roll (12) being attached directly or by means of a second intermediate member to the frame of the calender.

Description

Multirollcalender

TECHNICAL FIELD

The invention relates to a multiroll calender according to the preamble of claim 1.

The invention also relates to a method according to the preamble of claim 12.

BACKGROUND ART

In calendering, attempts are made to generally improve properties, such as smoothness, gloss and oil adsorptivity, of a web-like material, such as a paper or board web. In calendering, a web is passed into a nip defined between rolls pressed against each other, i.e. into a calendering nip, in which the web is deformed due to the effect of temperature, moisture and nip pressure. The nips in the calender are formed between a smooth-surfaced pressing roll, such as a metal roll, and a roll covered with an elastic cover, such as a polymer roll. The elastic- surfaced roll conforms to the shape of the web surface and presses the opposite side of the web evenly against the smooth-surfaced pressing roll. In this connection, by calender rolls are meant rolls that form a calendering nip, by a top roll is meant the uppermost roll of a roll stack, by a bottom roll is meant the lowermost roll of a roll stack, and by intermediate rolls are meant rolls between a top roll and a bottom roll. By a top nip is meant the uppermost calendering nip defined between the top roll and a calender roll located under the top roll, by a bottom nip is meant the lowermost calendering nip of a roll stack defined between the bottom roll and a calender roll located above the bottom roll, and by intermediate nips are meant calendering nips that are formed by means of calender rolls between the top nip and the bottom nip of the calender. Typically, compression is provided in a multiroll calender by fixing the top roll or the bottom roll of the roll stack in place and by pressing the roll stack against the roll fixed in place. Alternatively, both the top roll and the bottom roll are both pressed towards each other either such that none of the intermediate rolls is fϊx- edly locked in place or such that at least one of the intermediate rolls is fixedly locked in place. The deflections of the rolls can be compensated for by means of deflection-compensation devices generally provided in the top and bottom rolls such that the roll nips obtain a rectilinear form.

FI patent application 20041260 describes a multiroll calender having at least one roll stack formed of a top roll, a bottom roll and at least one intermediate roll between the top and bottom rolls, which are supported on a calender frame. The roll stack comprises at least two calendering nips, a fibrous web being calendered in at least one of them. An auxiliary frame is arranged in connection with the calender, to which auxiliary frame a soft-surfaced upper roll of the auxiliary frame and a soft-surfaced lower roll of the auxiliary frame are attached to form a matte nip to enable a matte running mode. The auxiliary frame can be attached to the calender frame fixedly or by means of a lever mechanism or a guide mechanism. An intermediate piece is arranged between the rolls attached to the auxiliary frame to pre- vent nip contact in the matte nip when other qualities are calendered on the calender. At least one loading cylinder is arranged in connection with the auxiliary frame to provide loading in the matte nip and/or in other nips of the roll stack. The roll stack can be divided into two roll stacks by means of the auxiliary frame without changing the rolls of the calender.

US patent 6,248,215 describes a calender in which there is a roll stack comprising a top roll, a bottom roll and several intermediate rolls. The bottom roll is a deflection-compensated roll, which can be lifted by a cylinder device. The top roll is also a deflection-compensated roll provided with either a fixed shell or a movable shell. The intermediate roll above the bottom roll is supported on the frame of the calender by means of an articulated arm such that said intermediate roll can be locked in its lowered position. The intermediate roll under the top roll is also supported on the frame of the calender by means of an articulated arm such that said intermediate roll can be loaded against the top roll using a cylinder device attached to the articulated arm. By locking the intermediate roll above the bottom roll in the lowered position and by loading the bottom roll by the cylinder device against said intermediate roll, a calendering nip is formed between the bottom roll and said intermediate roll. By loading the intermediate roll under the top roll against the top roll, a calendering nip is formed between the top roll and said intermediate roll. In that case, the top roll can have a fixed shell. The articulated arm of the intermediate roll under the top roll can also be provided with a locking device, by which it can be locked in its lifted position. In that case, the top roll is a roll having a movable shell, allowing the loading of the nip between the top roll and said intermediate roll to be produced by means of the top roll having a movable shell.

DE patent 196 31 056 discloses a calender in which there is a roll stack comprising a top roll, a bottom roll and several intermediate rolls. An additional movable roll is arranged above the top roll or under the bottom roll, the top roll or, correspondingly, the bottom roll being provided with two opposed loading shoe rows. This makes it possible to arrange for the web one separate web-calendering nip between the top roll and the roll located above it or between the bottom roll and the roll under it. The calender can then be used as normal, the web running through all calendering nips or using only said one separate calendering nip, in which the web can be calendered. However, the known arrangement has the prob- lem that in connection with a grade change of the fibrous web it is necessary to pass the web along a new path, which slows down the grade change process. Also, this known arrangement does not make it possible to use several nips for matte qualities.

WO publication 2004/061222 discloses a calender comprising roll stacks placed one on top of another or side by side. Each roll stack comprises a top roll, a bot- torn roll and several intermediate rolls. The uppermost intermediate roll, which is a thermo roll, can be locked to a frame, enabling a separate nip to be formed between the top roll and the uppermost intermediate roll. When the uppermost intermediate roll is locked to the frame, the closing and loading of the uppennost nip between the top roll and the uppermost intermediate roll takes place by displacing the shell of the top roll from inside the roll. When the uppermost intermediate roll is unlocked, displacing the bottom roll and/or the shell of the bottom roll closes the uppermost nip. The publication also describes the locking of the lowermost intermediate roll to the frame in a corresponding manner, allowing a sepa- rate nip to be formed between the bottom roll and the lowermost intermediate roll. The publication also discloses a load adjustment arrangement fitted between bearing housings or support arms of two rolls placed on top of each other and forming a pair. The adjustment arrangement makes it possible to limit the linear load in the nip between the pair-forming rolls, or force the nip totally open.

The state-of-the-art arrangements do not provide a simple arrangement by means of which it would be possible to change a calender provided with one roll stack to a calender provided with two roll stacks located on top of each other.

Another problem associated with the state-of-the-art calenders arises in a situation where movable-shell deflection-compensated rolls are used for closing and loading a roll stack. The limited range of movement of the movable-shell deflection- compensated rolls, for example, ± 15 mm with respect to the roll centre, will then become a problem. When outside diameters of roll shells change with changing grinding or type of coating to the extent that the stroke length of the movable-shell roll does not suffice to close nips, intermediate pieces fitted between the mounting supports and the body of the roll have been used, as known in the art. In the case of certain roll diameters, the diameter of the roll to be replaced changes so much that a sufficient change of centres is not achieved by means of the intermediate piece of the roll to be replaced but it is necessary to detach the roll to be replaced in the calender and the roll remaining in the calender in order that intermediate pieces may be fitted for both rolls.

SUMMARY OF INVENTION

An object of the present invention is an arrangement allowing a calender comprising one roll stack to be easily changed to a calender comprising two separate roll stacks on top of each other.

The characteristic features of the calender according to the invention are stated in the characterizing part of claim 1.

The characteristic features of the method according to the invention are stated in the characterizing part of claim 12.

The calender comprises a frame and a roll stack supported on it. The roll stack is formed of a top roll and a bottom roll, at least one of which is movably supported on the frame of the calender, and of intermediate rolls provided with articulated arms. The calender has two operating states. In the first operating state, the calen- der comprises one roll stack and, in the second operating state, the calender comprises two separate roll stacks on top of each other.

In the first operating state, a given group of adjacent intermediate rolls, starting from the uppermost or the lowermost intermediate roll, is pivotally supported at a pivot point of the articulated arm of each intermediate roll on a first support member. This first support member is in turn detachably attached to the frame of the calender. The top roll or the bottom roll of the calender is additionally supported on the frame of the calender by means of a first, detachable intermediate member, by which it is possible to adjust the space reserved for the roll stack or roll stacks of the calender in the height direction. In the second operating state, the first support member is replaced with a second support member, which is detachably attached to the frame of the calender in place of the first support member. The lowermost roll of an upper roll stack or the uppermost roll of a lower roll stack or both is/are fixedly supported on the second support member, and an intermediate roll or intermediate rolls of the roll stack formed at the second support member is/are pivotally supported on the second support member by means of the pivot points of the articulated arms. The first intermediate member is removed, the top roll or the bottom roll being attached directly or by means of a second intermediate member to the frame of the calen- der.

In the calender provided with one roll stack, the top roll and the bottom roll are deflection-compensated rolls. In the calender provided with two roll stacks, the top rolls and the bottom rolls of both roll stacks are deflection-compensated rolls, the number of the deflection-compensated rolls being doubled. In the calender provided with two separate roll stacks it is possible to use different linear loads in both roll stacks, when needed. Control of two-sidedness, i.e. gloss and web profile, is thus improved in the calender provided with two separate roll stacks.

Improved serviceability and a less expensive structure are achieved by a calender comprising two roll stacks on top of each other in one and the same frame, as compared with a calender comprising two roll stacks side by side in separate frames attached to each other.

In this application, the roll stacks placed on top of each other do not only refer to a situation where straight lines drawn through the centres of the rolls of the roll stacks would be in a vertical plane but said straight lines can also form an angle with the vertical plane.

In the following, the invention will be described with reference to the appended figures but not limiting the invention exclusively to the illustration of the figures. BRIEF DESCRIPTION OF FIGURES

Figure 1 shows one multiroll calender in its first operating state, the calender comprising one roll stack.

Figure 2 shows the multiroll calender of Fig. 1 in its second operating state, two separate roll stacks being formed of one roll stack.

Figure 3 shows an alternative to the calender illustrated in Fig. 1 in its first operating state, the calender comprising one roll stack.

Figure 4 shows the multiroll calender of Fig. 3 in its second operating state, two separate roll stacks being formed of one roll stack.

Figure 5 shows a second multiroll calender in its first operating state, the calender comprising one roll stack.

Figure 6 shows the multiroll calender of Fig. 5 in its second operating state, two separate roll stacks being formed of one roll stack.

Figure 7 shows the multiroll calender of Fig. 5 in its first alternative second operating state, two separate roll stacks being formed of one roll stack.

Figure 8 shows the multiroll calender of Fig. 5 in its second alternative second operating state, two separate roll stacks being formed of one roll stack.

Figure 9 shows one possibility of increasing the movement of deflection- compensated end rolls of an upper roll stack shown in Fig. 2. DESCRIPTION OF PREFERRED EMBODIMENTS

Fig. 1 shows a multiroll calender in accordance with the invention in its first operating state, the calender comprising one roll stack. The calender comprises a verti- cal roll stack A, in which there are eight calender rolls 11, 12, 21-26. The calender rolls comprise a top roll 11 placed uppermost and a bottom roll 12 placed lowermost as well as six intermediate rolls 21-26 between them. Nips are formed between smooth-surfaced press rolls 21, 24, 26, such as metal rolls, and rolls 22, 23, 25 covered with an elastic cover, such as polymer rolls, which smooth-surfaced rolls and elastic-cover rolls are disposed alternately one after another. The top roll 11 and the bottom roll 12 are advantageously deflection-compensated rolls covered with an elastic cover and advantageously provided with movable shells. The second 22 and the third 23 intermediate roll, counted from above, are soft- surfaced, forming an intermediate nip called a reversing nip between themselves. The top roll 11 is stationarily supported by means of a first intermediate member 110 on a frame R of the calender, and the bottom roll 12 is movably supported at its bearing housings 12a on the frame R by means of a first guide mechanism 70. In addition, a first loading member 60, for example, a loading cylinder, is mounted between the bearing housings 12a of the bottom roll 12 and the frame R to enable the bottom roll 12 to be moved in a nip plane S for the purpose of closing and opening the nips. The intermediate rolls 21-26 are supported at their bearing housings 22a, 24a on a first end of an articulated arm 42, 44. The articulated arm 42, 44 is pivotally supported on the frame R by means of a pivot point 42a, 44a located in the centre part of the articulated arm 42, 44. A second end of the articulated arm 42, 44 is supported on the frame R by means of a relief member 52, 54, for example, a relief cylinder.

The calender shown in Fig. 1 also comprises a first support member 100, on which the articulated arms 42 of the three uppermost intermediate rolls 21-23 are pivotally supported by means of pivot points 42a. This first support member 100 is attached to the frame R, for example, with bolts and nuts in such a way that it can be detached from the frame R by relatively simple actions. The figure shows the articulated arms 42, 44 of only two intermediate rolls 22, 24, and the relief members 52, 53 connected to these arms in order that the figure should remain clearer. For the same reason, the figure does not show any take-out roll associated with each intermediate ro 11 21 -26.

Fig. 2 shows the calender of Fig. 1 in its second operating state, the calender comprising two separate roll stacks on top of each other. This second operating state is achieved such that the top roll 11 and the first intermediate member 110 associ- ated with it, as well as the three uppermost intermediate rolls 21-23 and the first support member 100 associated with them, are detached from the calender. After that, a second support member 120 is fitted in the calender in place of the first support member 100. The second support member 120 is formed of a first support part 121 and a second support part 122. The first support part 121 includes bear- ing housings 121a, 121b, in which the end bearings of the lowermost roll 220 of the upper roll stack B and the end bearings of the uppermost roll 230 of the lower roll stack C are mounted. The bearing housings 121a, 121b are formed such that the outer surface of the shell of the lowermost roll 220 in the upper roll stack B is spaced from the outer surface of the shell of the uppermost roll 230 in the lower roll stack C. The lowermost roll 220 of the upper roll stack B and the uppermost roll 230 of the lower roll stack C are fixedly supported at their end bearings on the first support part 121 of the second support member 120, and the second support member 120 is fixedly supported on the frame R of the calender. The lowermost roll 220 of the upper roll stack B and the uppermost roll 230 of the lower roll stack C are advantageously deflection-compensated rolls provided with movable shells. The intermediate roll 21 of the upper roll stack B is supported at its bearing housing 21a on an articulated arm 41, and the articulated arm 41 is supported at a pivot point 41a on the second support part 122 of the second support member 120. The top roll 11 is supported directly on the frame R without an intennediate member 110. In other words, in Fig. 2, the calender of Fig. 1 comprising one set 'of rolls A is formed into a calender comprising two sets of rolls B, C and having the separate roll stacks B₅ C located on top of each other. In the upper roll stack B there are three rolls 11, 21, 220 and in the lower roll stack C there are five rolls 230, 24, 25, 26, 12. The upper roll stack B is closed and its nips are loaded by means of deflection-compensated rolls 11, 220 provided with a movable shell. The lower roll stack C is closed by means of the first loading member 60 and its nips are loaded by means of deflection-compensated rolls 230, 12 provided with a movable shell. The division into two separate roll stacks B, C is thus made at the rolls 22, 23 forming a reversing nip in the original roll stack A. The upper roll 22 of the reversing nip is replaced with a deflection-compensated roll having a movable shell and forming the bottom roll 220 of the upper roll stack B, and the lower roll 23 of the reversing nip is replaced with a deflection-compensated roll having a movable shell and forming the top roll 230 of the lower roll stack C.

Fig. 3 shows an alternative to the calender shown in Fig. 1 in its first operating state, the calender comprising one roll stack. In this embodiment, the situation is inverted with respect to that illustrated in Fig. 1 such that the bottom roll 12 is fixedly supported at its bearing housings 12a on the calender frame R by means of a first intermediate member 110, and the top roll 11 is movably supported on the calender frame R by means of a first loading member 60. Three intermediate rolls 24-26 above the bottom roll 12 are here pivotally supported at pivot points of articulated arms on a first support member 100. Fig. 3, like Fig. 1, also shows articulated arms 43, 45 of only two intermediate rolls 23, 25 and relief members 53, 55 associated with them in order that the figure should remain clearer. For the same reason, the figure does not show any take-out roll associated with each intermediate roll 21-26.

Fig. 4 shows the multiroll calender of Fig. 3 in its second operating state, two separate roll stacks being fonned of one roll stack. In this embodiment, the situation is inverted with respect to that illustrated in Fig. 2 such that the upper roll stack B is formed of five rolls and the lower roll stack C is formed of three rolls. The division into two separate roll stacks B, C is thus made at the rolls 24, 25 forming a reversing nip in the original roll stack A. The upper roll 24 of the reversing nip is replaced with a deflection-compensated roll having a movable shell and forming the bottom roll 240 of the upper roll stack B, and the lower roll 25 of the reversing nip is replaced with a deflection-compensated roll having a movable shell and forming the top roll 250 of the lower roll stack C.

Fig. 5 shows another multiroll calender in its first operating state, the calender comprising one roll stack. The calender comprises a vertical roll stack A having ten calender rolls 11, 12, 31-38. The calender shown in Fig. 5 corresponds to the calender shown in Fig. 1 in other respects, and therefore it is not described here in more detail. Fig. 5, like Fig. 1, also shows articulated arms 44, 46 of only two intermediate rolls 34, 36, and relief members 54, 56 associated with them in order that the figure should remain clearer. For the same reason, the figure does not show any take-out roll associated with each intermediate roll 31-38.

Fig. 6 shows the calender shown in Fig. 5 in its second operating state, the calender comprising two separate roll stacks. This second operating state is, in princi- pie, achieved in the same way as in the calender shown in Fig. 2 but, in this case, the top roll 11 is not supported directly on the frame R but, instead, it is supported on the calender frame R by means of a second guide mechanism 71 placed in connection with a second support member 120 in a manner corresponding to the manner in which the bottom roll 12 is supported on the calender frame R by means of a first guide mechanism 70. A second loading member 61, for example, a loading cylinder is additionally mounted in place of the first intermediate member 110 to enable the top roll 11 to be moved in the second guide mechanism 71. This second loading member 61 is needed in order that the upper set of rolls B may also be closed in a situation where the diameters of the calender rolls of the upper set of rolls B have become smaller as a result of grinding. In other words, in Fig. 6, the calender comprising one set of rolls A shown in Fig. 5 is formed into a calender comprising two sets of rolls B, C, in which the separate roll stacks B, C are located on top of each other. In the upper roll stack B there are five rolls 11, 31, 32, 33, 340 and in the lower roll stack C there are also five rolls 350, 36, 37, 38, 12. In this embodiment, the upper roll stack B is closed using the second loading member 61, and its nips are loaded with deflection- compensated rolls 11, 340 having a movable shell. The lower roll stack C is closed using the first loading member 60, and its nips are loaded with deflection- compensated rolls 350, 12 having a movable shell. The division into two separate roll stacks B, C is thus made at the rolls 34, 35 forming a reversing nip in the original roll stack A. The upper roll 34 of the reversing nip is replaced with a deflection-compensated roll having a movable shell and forming the bottom roll 340 of the upper roll stack B₅ and the lower roll 35 of the reversing nip is replaced with a deflection-compensated roll having a movable shell and forming the top roll 350 of the lower roll stack C.

Fig. 6 also shows fixed stop members 56a of the lever arms 46 of the intermediate rolls in the lower roll stack C. When the first loading member 60 is driven to a bottom position, the intermediate rolls 36-38 move down until the fixed stop members 56a stop the movement of the lever arm 46, the nips of the lower roll stack C remaining open. The lever arms 46 press against the fixed stop members 56a because of the weight of the intermediate rolls 31-33, and the lever arms 46 can be locked against the fixed stop members 56a with the relief members 56.

Fig. 6 additionally shows adjustable stop members 53a associated with articulated arms 43 of the intermediate rolls in the upper roll stack B. In the initial situation, relief members 53 are driven to the bottom of their stroke, the nip gaps being then at their maximum. The closing of the nips of the upper roll stack B is started by raising the shell of the lowermost movable-shell roll 340 in the upper roll stack B to a top position. After that, the top roll 11 is moved downward by means of the second loading member 61, the nips thus closing from above downwards. The intermediate rolls 31-33 have full relief. In the running situation, the second loading member 61 is locked and nip loads are adjusted by means of the movable-shell top roll 11 and the lowermost movable-shell roll 340 of the upper roll stack B. The opening of the nips of the upper roll stack B is accomplished by means of the lowermost movable-shell roll 340 of the upper roll stack B, which is driven to the bottom position, the intermediate rolls 33, 32, 31 following and stopping at the adjustable stop member 53a so that a gap of about 5 mm is formed in the nips, said gap in the case of four nips totalling 20 mm. The top roll 11 remains in place. The stroke length of 50 mm of the lowermost movable-shell roll 340 in the upper roll stack B suffices well to close said 20 mm gap. As a result of grinding, the outside diameters of the shells of the rolls 11, 31-33, 340 in the upper roll stack B are, however, reduced to such an extent that the stroke length of the lowermost movable-shell roll 340 of the upper roll stack B does not suffice any more to close the nips. In that case, the setting of the stop members 53a of the intermediate rolls 31-33 in the upper roll stack B must be adjusted in such a way that they will allow the intermediate rolls 31-33 to descend slightly in order that the total gap in the opening situation may be adjusted to a level such that the stroke length of the lowermost movable-shell roll 340 of the upper roll stack B suffices to close the nips. At the same time, the top roll 11 is lowered downward by means of the sec- ond loading member 61. A larger nip gap required by tail threading is arranged by driving the relief members 53 to an out-stroke position and by raising the top roll 11 up by means of the second loading member 61, thereby providing gaps of over 10 mm in the nips between the rolls 11, 31-33, 340.

Fig. 7 shows the multiroll calender of Fig. 5 in a first alternative second operating state, two separate roll stacks being formed of one roll stack. In this embodiment, the top roll 11 is stationarily supported directly at its bearing housings 1 Ia on the machine frame R. The lowermost roll 340 of the upper roll stack B is supported in this embodiment on a second guide mechanism 71 placed in connection with a second support member 120. The bearing housings 340a of the lowermost roll 340 of the upper roll stack B are additionally supported on the calender frame R by means of a second loading member 61. The second loading member 61 is placed on top of a first support part 121 of the second support member 120. Only the uppermost roll 350 of the lower roll stack C is thus here placed in the first support part 121 of the second support member 120.

In other words, in Fig. 7, the calender of Fig. 5 comprising one set of rolls A is formed into a calender comprising two sets of rolls B, C, in which the separate roll stacks B, C are located on top of each other. In the upper roll stack B there are five rolls 11, 31, 32, 33, 340 and in the lower roll stack C there are also five rolls 350, 36, 37, 38, 12. In this embodiment, the upper roll stack B is closed using the second loading member 61, and its nips are loaded with movable-shell deflection- compensated rolls 11, 340. The lower roll stack C is closed using the first loading member 60, and its nips are loaded with movable-shell deflection-compensated rolls 350, 12. In this embodiment, fixed stop members can be used both in the upper B and in the lower C roll stack.

Fig. 8 shows the multiroll calender of Fig. 5 in its second alternative second operating state, two separate roll stacks being formed of one roll stack. Here, the original number of the calender rolls is decreased by two, i.e. the original inter- mediate rolls 31 and 32 are removed. In the upper roll stack B there are thus three rolls 11, 33, 340 and in the lower roll stack C there are five rolls 350, 36-38, 12. In addition, the first intermediate member 110 is replaced with a second intermediate member 130, by means of which the space of the roll stacks B, C in the height direction of the calender is adjusted to be suitable. Since the second inter- mediate member 130 becomes relatively high, it is additionally supported from the side on a second support member 120 or directly on the frame R.

Fig. 9 shows a possibility of increasing the movement of the movable-shell deflection-compensated end rolls 11, 220 of the upper roll stack B shown in Fig. 2. The movable-shell deflection-compensated rolls 11, 220 are stationarily supported at their^' bearing housings l la, 220a on the calender frame R. The deflection- compensated rolls 11 , 220 are provided with a cylindrical bearing housing 510, 520, which is mounted on an articulation bearing of the support point and the inside and outside diameters of which are eccentric with respect to each other. By turning the eccentric housing, the deflection-compensated roll 11 , 220 is caused to move with respect to its support centre in the nip direction S. The magnitude of the turning angle of the eccentric housing is determined based on changes in roll diameters, and operation positions are locked mechanically. This kind of eccentric arrangement makes it possible to increase the movement of the deflection- compensated rolls such that the movement of the shells of the deflection- compensated rolls suffices to also close the nips in a situation where the diameters of the shells of the rolls 11, 21, 220 in the upper roll stack B have been reduced as a result of grinding or replacement of coating. The figure also shows a take-out roll 421 of the intermediate roll 21.

In the embodiments shown in the figures, the second support member 120 is formed of a first support part 121 and a second support part 122. These support parts 121, 122 forming the second support member 120 can be formed of one piece or of two separate pieces.

In the embodiments illustrated in the figures, either the top roll 1 1 or the bottom roll 12 is movably supported by means of a loading member on the calender frame. The invention can naturally also be applied in a situation where both the top roll 11 and the bottom roll 12 are movably supported by means of loading members on the calender. In that case, under either loading member it is possible to use a detachable intermediate member enabling the state of the calender stack in the calender to be adjusted in the height direction.

In the embodiments illustrated in the figures, the intermediate rolls are supported on the frame such that the bearing housing of the intermediate roll is attached to one end of a lever arm, a relief cylinder is attached to the other end of the lever arm, and the lever arm is supported at its pivot point located in its centre part on the frame. The invention can naturally be applied equally well to a calender in which the intermediate rolls are supported on the frame such that the bearing housing of the intermediate roll is attached to the first end of the lever arm, the lever arm is supported on the frame at a pivot point located at its second end op- posite to the first end, and the relief cylinder is attached to the articulated arm between the bearing housing and the pivot point.

In the figures, the invention is applied to a calender having eight rolls and to a calender having ten rolls. The invention can naturally be applied to any calender having a top roll, a bottom roll and a number of intermediate rolls.

In the figures, the invention is applied to a calender in which a straight line drawn through the centres of the rolls in the roll stacks A, B, C is in a vertical plane, but the invention cal naturally also be applied in a situation where a straight line drawn through the centres of the rolls in the roll stacks forms an angle with a vertical plane.

On the calender in accordance with the invention it is naturally also possible to carry out different partial nip runs known per se in both operating states. In that case, one or some of the intermediate rolls is/are locked and only one or some of the calender nips is/are used for calendering a web.

Above, the invention has been described by way of example with reference to the figures in the appended drawings. However, the invention is not limited only to the illustration of the figures but the different embodiments of the invention may vary within the inventive idea defined in the appended claims.

Claims

1. A multiroll calender (K) comprises a frame (R) and a roll stack (A) supported on the frame, which roll stack (A) comprises a top roll (11) and a bottom roll (12), of which at least one is movably supported on the frame (R) of the calender, and intermediate rolls (21-26; 31-38) whose end bearings are supported on articulated arms, and which articulated arms are pivotaily supported by means of pivot points on the frame (R) of the calender, the calender comprising a first operating state, in which the roll stack (A) operates as one roll stack, and a second operating state, in which the roll stack (A) is divided into an upper roll stack (B) and a lower roll stack (C), characterized in that in the first operating state: a pre-selected group of adjacent intermediate rolls, starting from the uppermost or the lowermost intermediate roll, is pivotaily supported by means of the pivot point of the articulated arm of each intermediate roll on a first support member (100) detachably attached to the frame (R) of the calender, the rest of the intermediate rolls being pivotaily supported by means of the pivot points of the articulated arms of the intermediate rolls directly on the frame (R), - the bottom roll (12) or the top roll (11) is supported by means of a detachable first intermediate member (110) on the frame (R) of the calender, in the second operating state:

- the first support member (100) is replaced with a second support member

(120) detachably attached to the frame (R) of the calender in place of the first support member (100), the lowermost roll of the first roll stack (B) or the uppermost roll of the second roll stack (C) or both being stationarily supported on the second support member (120), and an intermediate roll or intermediate rolls of the roll stack formed at the second support member

(120) being pivotaily supported by means of the pivot points of the articu- lated arms on the second support member (120), - the first intermediate member (110) is removed, the top roll (11) or the bottom roll (12) being stationarily supported directly or by means of a second detachable intermediate member (130) on the frame (R) of the calender or movably supported by means of a second loading member (61) on the frame (R) of the calender.

2. A calender as claimed in claim 1, characterized in that the top roll (11) and the bottom roll (12) are deflection-compensated rolls provided with a movable shell.

3. A calender as claimed in claim 1 or 2, characterized in that the calender comprises, in the first operating state, a roll stack (A) having six intermediate rolls (21-26) and, in the second operating state, an upper roll stack (B) having one intermediate roll (21) and a lower roll stack having three intermediate rolls (24-26), so that - in the first operating state, the three uppermost intermediate rolls (21-23) are pivotally supported by means of the pivot points of the articulated arms of the intermediate rolls on the first support member (100), the top roll (11) is stationarily supported by means of the first intermediate member (110) on the frame (R) of the calender, and the bottom roll (12) is movably supported by means of a first loading member (60) on the frame (R) of the calender, in the second operating state, the first intermediate member (110) is removed, and the top roll (11) is stationarily supported directly on the frame (R) of the calender, the lowermost roll (220) of the upper roll stack (B) and the uppermost roll (230) of the lower roil stack (C) are stationarily supported on the second support member (120) at a distance from each other, and the only intermediate roll (21) of the upper roll stack (B) is pivotally supported by means of the pivot point of the articulated arm of the intermediate roll on the second support member (120), and the three in- termediate rolls (24-26) of the lower roll stack (C) remain supported by means of the pivot points of their articulated arms on the frame (R) of the calender in the same manner as in the first operating state, and the bottom roll (12) remains movably supported by means of the first loading member (60) on the frame (R) of the calender in the same manner as in the first operating state.

4. A calender as claimed in claim 3, characterized in that the lowermost roll (220) of the upper roll stack (B) and the uppermost roll (230) of the lower roll stack (C) are deflection-compensated rolls provided with a movable shell.

5. A calender as claimed in claim 4, characterized in that end bearings of the top • roll (11) and end bearings of the lowermost roll (220) in the upper roll stack (B) are mounted in a cylindrical bearing housing (510, 520), whose inside and outside diameters are eccentric with respect to each other.

6. A calender as claimed in claim 1 or 2, characterized in that the calender comprises, in the first operating state, a roll stack (A) having six intermediate rolls (21-26) and, in the second operating state, an upper roll stack (B) having three intermediate rolls (21-23) and a lower roll stack having one intermediate roll (26), so that - in the first operating state, the three lowermost intermediate rolls (21-23) are pivotally supported by means of the pivot points of the articulated arms of the intermediate rolls on the first support member (100), the bottom roll (12) is stationarily supported by means of the first intermediate member (110) on the frame (R) of the calender, and the top roll (1 1) is movably supported by means of a first loading member (60) on the frame (R) of the calender,

- in the second operating state, the first intermediate member (110) is removed, and the bottom roll (12) is stationarily supported directly on the frame (R) of the calender, the lowermost roll (240) of the upper roll stack (B) and the uppermost roll (250) of the lower roll stack (C) are stationarily supported on the second support member (120) at a distance from each other, and the only intermediate roll (26) of the lower roll stack (C) is piv- otally supported by means of the pivot point of the articulated arm of the intermediate roll on the second support member (120), and the three intermediate rolls (21-23) of the upper roll stack (B) remain supported by means of the pivot points of their articulated arms on the frame (R) of the calender in the same manner as in the first operating state, and the top roll (11) remains movably supported by means of the first loading member (60) on the frame (R) of the calender in the same manner as in the first operating state.

7. A calender as claimed in claim 6, characterized in that the lowermost roll (240) of the upper roll stack (B) and the uppermost roll (250) of the lower roll stack (C) are deflection-compensated rolls provided with a movable shell.

8. A calender as claimed in claim 1 or 2, characterized in that the calender comprises, in the first operating state, a roll stack (A) having eight intermediate rolls (31-38) and, in the second operating state, an upper roll stack (B) having three intermediate rolls (31-33) and a lower roll stack also having three intermediate rolls (36-38), so that - in the first operating state, the five uppermost intermediate rolls (31-35) are pivotally supported at the pivot points of the articulated arms of the intermediate rolls on the first support member (100), the top roll (11) is sta- tionarily supported by means of the first intermediate member (110) on the frame (R) of the calender, and the bottom roll (12) is movably supported by means of a first loading member (60) on the frame (R) of the calender, in the second operating state, the first intermediate member (110) is removed, and the top roll (1 1) is movably supported by means of the second loading member (61) on the frame (R) of the calender, the lowermost roll (340) of the upper roll stack (B) and the uppermost roll (350) of the lower roll stack (C) are stationarily supported on the second support member

(120) at a distance from each other, and the three intermediate rolls (31- 33) of the upper roll stack (B) are pivotally supported .by means of the pivot points of the articulated arms of the intermediate rolls on the second support member (120), and the three intermediate rolls (36-38) of the lower roll stack (C) remain supported by means of the pivot points of the articulated arms on the frame (R) of the calender in the same manner as in the first operating state, and the bottom roll (12) remains movably supported by means of the first loading member (60) on the frame (R) of the calender in the same manner as in the first operating state.

9. A calender as claimed in claim 8, characterized in that the lowermost roll (340) of the upper roll stack (B) and the uppermost roll (350) of the lower roll stack (C) are deflection-compensated rolls provided with a movable shell.

10. A calender as claimed in claim 1 or 2, characterized in that the calender comprises, in the first operating state, a roll stack (A) having eight intermediate rolls (31-38) and, in the second operating state, an upper roll stack (B) having three intermediate rolls (31-33) and a lower roll stack also having three intermediate rolls (36-38), so that in the first operating state, the five uppermost intermediate rolls (31-35) are pivotally supported by means of the pivot points of the articulated arms of the intermediate rolls on the first support member (100), the top roll

(11) is stationarily supported by means of the first intermediate member

(110) on the frame (R) of the calender, and the bottom roll (12) is movably supported by means of a first loading member (60) on the frame (R) of the calender, in the second operating state, the first intermediate member (110) is removed, and the top roll (11) is stationarily supported directly on the frame (R) of the calender, the uppermost roll (350) of the lower roll stack (C) is stationarily supported on the second support member (120) and the Io w- ermost roll (340) of the upper roll stack (B) is movably supported by means of the second loading member (61) on a second support part (120), and the three intermediate rolls (31-33) of the upper roll stack (B) are piv- otally supported by means of the pivot points of the articulated arms of the intermediate rolls on the second support member (120), and the three intermediate rolls (36-38) of the lower roll stack (C) remain supported by means of the pivot points of the articulated arms on the frame (R) of the calender in the same manner as in the first operating state.

11. A calender as claimed in claim 10, characterized in that the lowermost roll (340) of the upper roll stack (B) and the uppermost roll (350) of the lower roll stack (C) are deflection-compensated rolls provided with a movable shell.

12. A method in a multiroll calender (K), which multiroll calender comprises a frame (R) and a roll stack (A) supported on the frame, which roll stack (A) comprises a top roll (11) and a bottom roll (12), of which at least one is movably sup- ported on the frame (R) of the calender, and intermediate rolls (21-26; 31-38) whose end bearings are supported on articulated arms, and which articulated arms are pivotally supported by means of pivot points on the frame (R) of the calender, the calender being provided with a first operating state, in which the roll stack (A) operates as one roll stack, and with a second operating state, in which the roll stack (A) is divided into an upper roll stack (B) and a lower roll stack (C), characterized by the steps of in the first operating state: selecting a group of adjacent intermediate rolls, starting from the uppermost or the lowermost intermediate roll, and pivotally supporting the group by means of the pivot point of the articulated arm of each intermediate roll on a first support member (100) detachably attached to the frame (R) of the calender, the rest of the intermediate rolls being pivotally supported by means of the pivot points of the articulated arms of the intermediate rolls directly on the frame (R), - supporting the bottom roll (12) or the top roll (11) by means of a detachable first intermediate member (110) on the frame (R) of the calender, in the second operating state: replacing the first support member (100) with a second support member (120) detachably attached to the frame (R) of the calender in place of the first support member (100), the lowermost roll of the upper roll stack (B) or the uppermost roll of the lower roll stack (C) or both being stationarily supported on the second support member (120), and an intermediate roll or intermediate rolls of the roll stack formed at the second support member (120) being pivotally supported by means of the pivot points of the articulated arms on the second support member (120), - removing the first intermediate member (110), the top roll (11) or the bottom roll (12) being stationarily supported directly or by means of a second detachable intermediate member (130) on the frame (R) of the calender or movably supported by means of a second loading member (61) on the frame (R) of the calender.

13. A method as claimed in claim 11, characterized by the step of using deflection-compensated rolls provided with a movable shell as the top roll (11) and as the bottom roll (12).

14. A method as claimed in claim 12 or 13, characterized by the steps of providing the calender, in the first operating state, with a roll stack (A) having six intermediate rolls (21-26) and, in the second operating state, with an upper roll stack (B) having one intermediate roll (21) and with a lower roll stack having three intermediate rolls (24-26), - in the first operating state, pivotally supporting the three uppermost intermediate rolls (21-23) by means of the pivot points of the articulated arms of the intermediate rolls on the first support member (100), stationarily supporting the top roll (11) by means of the first intermediate member (110) on the frame (R) of the calender, and movably supporting the bottom roll (12) by means of a first loading member (60) on the frame (R) of the calender, in the second operating state, removing the first intermediate member (110), and stationarily supporting the top roll (11) directly on the frame (R) of the calender, stationarily supporting the lowermost roll (220) of the upper roll stack (B) and the uppermost roll (230) of the lower roll stack (C) on the second support member (120) at a distance from each other, and pivotally supporting the only intermediate roll (21) of the upper roll stack (B) by means of the pivot point of the articulated arm of the intermediate roll on the second support member (120), and keeping the three intermediate rolls (24-26) of the lower roll stack (C) supporte.d by means of the pivot points of their articulated arms on the frame (R) of the calender in the same manner as in the first operating state, and keeping the bottom roll (12) movably supported by means of the first loading member (60) on the frame (R) of the calender in the same manner as in the first operating state.

15. A method as claimed in claim 14, characterized by the step of using deflection-compensated rolls provided with a movable shell as the lowermost roll (220) of the upper roll stack (B) and as the uppermost roll (230) of the lower roll stack ^" (C).

16. A method as claimed in claim 15, characterized by the step of mounting end bearings of the top roll (11) and end bearings of the lowermost roll (220) in the upper roll stack (B) in a cylindrical bearing housing (510, 520), whose inside and outside diameters are eccentric with respect to each other.

17. A method as claimed in claim 12 or 13, characterized by the steps of providing the calender, in the first operating state, with a roll stack (A) having six intermediate rolls (21-26) and, in the second operating state, with an upper roll stack (B) having three intermediate rolls (21-23) and with a lower roll stack having one intermediate roll (26), - in the first operating state, pivotally supporting the three lowermost intermediate rolls (21-23) by means of the pivot points of the articulated arms of the intermediate rolls on the first support member (100), stationarily supporting the bottom roll (12) by means of the first intermediate member (110) on the frame (R) of the calender, and movably supporting the top roll (11) by means of a first loading member (60) on the frame (R) of the calender, in the second operating state, removing the first intermediate member (110), and stationarily supporting the bottom roll (12) directly on the frame (R) of the calender, stationarily supporting the lowermost roll (240) of the upper roll stack (B) and the uppermost roll (250) of the lower roll stack (C) on the second support member (120) at a distance from each other, and pivotally supporting the only intermediate roll (26) of the lower roll stack (C) by means of the pivot point of the articulated arm of the intermediate roll on the second support member (120), and keeping the three intermediate rolls (21-23) of the upper roll stack (B) supported by means of the pivot points of their articulated arms on the frame (R) of the calender in the same manner as in the first operating state, and keeping the top roll (11) movably supported by means of the first loading member (60) on the frame (R) of the calender in the same manner as in the first operating state.

18. A method as claimed in claim 17, characterized by the step of using deflection-compensated rolls provided with a movable shell as the lowermost roll (240) of the upper roll stack (B) and as the uppermost roll (250) of the lower roll stack (C).

19. A calender as claimed in claim 12 or 13, characterized by the steps of providing the calender, in the first operating state, with a roll stack (A) having eight intermediate rolls (31-38) and, in the second operating state, with an upper roll stack (B) having three intermediate rolls (31-33) and with a lower roll stack also having three intermediate rolls (36-38), in the first operating state, pivotally supporting the five uppermost intermediate rolls (31-35) at the pivot points of the articulated arms of the intermediate rolls on the first support member (100), stationarily supporting the top roll (11) by means of the first intermediate member (110) on the frame (R) of the calender, and movably supporting the bottom roll (12) by means of a first loading member (60) on the frame (R) of the calender, in the second operating state, removing the first intermediate member (110), and movably supporting the top roll (11) by means of the second loading member (61) on the frame (R) of the calender, stationarily sup- porting the lowermost roll (340) of the upper roll stack (B) and the uppermost roll (350) of the lower roll stack (C) on the second support member (120) at a distance from each other, and pivotally supporting the three intermediate rolls (31-33) of the upper roll stack (B) by means of the pivot points of the articulated arms of the intermediate rolls on the second sup- port member (120), and keeping the three intermediate rolls (36-38) of the lower roll stack (C) supported by means of the pivot points of the articulated arms on the frame (R) of the calender in the same manner as in the first operating state, and keeping the bottom roll (12) movably supported by means of the first loading member (60) on the frame (R) of the calender in the same manner as in the first operating state.

20. A method as claimed in claim 19, characterized by the step of using deflection-compensated rolls provided with a movable shell as the lowermost roll (340) of the upper roll stack (B) and as the uppermost roll (350) of the lower roll stack (C).

21. A method as claimed in claim 12 or 13, characterized by the steps of providing the calender, in the first operating state, with a roll stack (A) having eight intermediate rolls (31-38) and, in the second operating state, with an upper roll stack (B) having three intermediate rolls (31-33) and with a lower roll stack also having three intermediate rolls (36-38), in the first operating state, pivotally supporting the five uppermost intermediate rolls (31-35) by means of the pivot points of the articulated arms of the intermediate rolls on the first support member (100), stationarily supporting the top roll (11) by means of the first intermediate member (110) on the frame (R) of the calender, and movably supporting the bottom roll (12) by means of a first loading member (60) on the frame (R) of the calender, in the second operating state, removing the first intermediate member (110), and stationarily supporting the top roll (11) directly on the frame (R) of the calender, stationarily supporting the uppermost roll (350) of the lower roll stack (C) on the second support member (120), and movably supporting the lowermost roll (340) of the upper roll stack (B) by means of the second loading member (61) on a second support part (120), and pivotally supporting the three intermediate rolls (31-33) of the upper roll stack (B) by means of the pivot points of the articulated arms of the intermediate rolls on the second support member (120), and keeping the three intermediate rolls (36-38) of the lower roll stack (C) supported by means of the pivot points of the articulated arms on the frame (R) of the calender in the same manner as in the first operating state.

22. A method as claimed in claim 21, characterized by the step of using deflection-compensated rolls provided with a movable shell as the lowermost roll (340) of the upper roll stack (B) and as the uppermost roll (350) of the lower roll stack (C).