WO2003031718A1

WO2003031718A1 - Roll replacement device

Info

Publication number: WO2003031718A1
Application number: PCT/FI2002/000787
Authority: WO
Inventors: Pekka Linnonmaa; Markku Kyytsönen; Markku Kirvesmäki; Hannu Pullinen
Original assignee: Metso Paper, Inc.
Priority date: 2001-10-10
Filing date: 2002-10-08
Publication date: 2003-04-17
Also published as: FI20011975A0; DE10297318T5; FI110955B; DE10297318B4

Abstract

A roll replacement device (8) for a multi-nip calender of a paper machine, which device comprises: a frame is transverse to the machine direction of the paper machine and which comprises vertical parts (81) and a horizontal part between them; a service platform (83) which is between the vertical parts and movable in the vertical direction; and calender roll (2, 3) replacement means (9), and which roll replacement device moves on guide rails (85) forwards and backwards in the machine direction. It is characteristic of the invention that the service platform and the calender roll replacement means are able to move past each other in the vertical direction, that the calender roll replacement means grip the calender roll at the neck or at the bearing housing of the axle of the roll or outside the bearing housing, and that the roll replacement device moves in the machine direction forwards and backwards between a home station and a work station.

Description

Roll replacement device

The present invention relates to multi-nip calenders of a paper machine. More specifically, the present invention relates to a roll replacement device for a multi- nip calender of a paper machine, which device comprises a frame which is transverse to the machine direction (MD, Machine Direction) parallel to the direction of the web of the paper machine and which comprises vertical parts and a horizontal part between them; a service platform which is arranged and supported between the vertical parts so as to be movable in the vertical direction; and calender roll replacement means for gripping and detaching a selectable first calender roll as well as fitting back a selectable second calender roll in the calender, and which roll replacement device moves along a predetermined path, preferably along guide rails, forwards and backwards in the machine direction.

This kind of roll replacement device for a multi-nip calender of a paper machine is known from the applicant's DE utility model application No. 2000 1001.8. A drawback in this prior art roll replacement device is that the structural arrangement according to it is complicated and thus expensive. A drawback and a weakness is also that, although the service platform and the support structure of a detached roll package are movable independently of each other in the vertical direction, the service platform is movable only below the support structure of the roll package; in a corresponding manner, the support structure of the roll package is movable only above the service platform, wherefore the roll replacement device is not suitable for replacement of a bottom roll of a calender.

Traditionally, replacement of a calender roll is carried out by means of lifting sleeves clamped to the ends of the roll axle and using an overhead hall crane. Today, however, increased roll widths and both roll and axle weights and, further, coupling sleeves for ducts for passing heating oil, which are needed in particular at the ends of the axle journals of heatable calender rolls, have grown to the extent that the roll and axle masses and the roll widths in particular begin to be determining dimensioning quantities of calender rolls. In that connection, a problem will be posed by the fact that the support points of the calender roll to be detached remain very far from each other, and the speed or the machine width of the paper machine cannot be increased any more in accordance with the criteria of production economy, and by the fact that it is very difficult, if at all possible, to detach and/or change calender rolls dimensioned according to the criteria of production economy by means of today's overhead hall cranes in today's machine halls.

The primary object of the present invention is to eliminate or at least substantially reduce the drawbacks and weaknesses of the prior art arrangements and to provide an improved roll replacement device for a multi-nip calender.

This object is achieved by a roll replacement device of a multi-nip calender like the one described at the beginning, the characteristic special features of which device are set forth in the appended set of claims.

Generally, the present invention is thus based on the new and inventive basic idea that the service platform of the roll replacement device and the means for replacement of a calender roll, which is advantageously a bottom roll or a selectable intermediate roll, or of a roll package formed by a calender roll and its auxiliary devices, or at least the lifting arms included in the replacement means are able to move past each other in the vertical direction, that the replacement means grip the calender roll selectively at the neck or at the bearing housing of the axle of the roll or outside the bearing housing, and that the roll replacement device moves backwards and forwards in the machine direction between a home station, where the roll replacement device supports the calender roll or the roll package, and a work station, where the roll replacement device receives a selectable first calender roll or the roll package from the calender. It is characteristic of an advantageous embodiment of the invention that the service platform and the means of replacing an intermediate roll or a roll package comprising an intermediate roll in a calender, advantageously lifting arms for gripping a selectable first intermediate roll or roll package in a calender, for detaching selectable first intermediate roll or roll package from the calender and fitting a selectable second intermediate roll or roll package in the calender, which service platform and replacement means move vertically on the frame, are movable in the vertical direction independently of each other past each other substantially over the entire height of the frame.

For providing the calender roll replacement means with vertical movability it is advantageous in accordance with the invention that the replacement means include a pair of lifting arms, which are arranged to move, while retaining their position, vertically along the vertical parts of the frame. In that connection, it is preferable in accordance with an advantageous embodiment of the invention that the lifting arms are attached to slide parts moving along the vertical parts of the frame.

Since there are take-out rolls for the web outside the vertical set of calender rolls in the calender, it is to be recommended in accordance with the invention that the lifting arms are dimensioned to receive, as a whole, a selectable intermediate roll of the calender and a roll package formed by its auxiliary devices including at least a take-out roll for the web, so that the intermediate roll of the calender can be easily detached with its auxiliary devices on support of the lifting arms. It is preferable that an intermediate roll or a roll package in a calender is gripped and lifted at the neck or the bearing housing of the roll axle of the intermediate roll or outside the bearing housing.

When using the roll replacement device in accordance with the present invention, the calender roll taken away from the calender by means of the calender replacement device is intended to be removed from the lifting arms by using an overhead hall crane; likewise, the calender roll intended to be fitted in the calender is intended to be brought onto the lifting arms by using an overhead hall crane. Since the service platform allows all the auxiliary devices and oil feed arrangements to be taken out from the calender roll on the lifting arms, the width of the calender roll to be lifted and/or lowered can be minimized and, correspondingly, the end supports of the calender roll for lifting and lowering by an overhead hall crane are brought close to each other, which substantially reduces the risk of the calender roll being damaged.

Since the bottom roll of the calender typically weighs substantially more than the intermediate rolls of the calender, it is advantageous in accordance with the invention that, for the bottom roll of the calender, the calender roll replacement means are provided with supports for receiving and replacing the bottom roll, which supports are separate from the lifting arms and disposed at the foot of the vertical parts. Advantageously, the support for receiving and replacing the bottom roll is disposed on or in the base of the vertical part of the roll replacement means, said base being provided with wheels.

In order that the roll replacement device in accordance with the invention should be suitable for roll replacement while the calender roll is still hot, in accordance with one advantageous embodiment of the invention, the roll replacement device is additionally provided with a drive for rotating the calender roll, whereby it is possible to substantially prevent damage from being caused by the thermal stresses of the roll. The rotation drive or drives can be fitted to the lifting arms for intermediate rolls and/or to the supports for receiving and replacing the bottom roll.

In the following, the invention will be described by way of example by means of one of its embodiments considered advantageous but without confining to said embodiment, with reference to the appended patent drawings, in which FIG. 1A and FIG. IB show a roll replacement device in accordance with the invention for replacement of an intermediate roll in a multi-nip calender, and FIG. 2A and FIG. 2B show a roll replacement device in accordance with the invention for replacement of a bottom roll in a multi-nip calender.

Figs. 1A, IB, 2 A and 2B show a multi-nip calender 1, in which there are eight calender rolls arranged vertically one upon the other and being, in the direction from top to bottom, a top roll 2, six intermediate rolls 3 and a bottom roll 4 of the multi-nip calender 1, and seven nips 5 formed between the shell surfaces of each pair of calender rolls 2, 3; 3, 3; ... 3,4 loaded against each other. In addition, the multi-nip calender 1 comprises several take-out rolls 6 for guiding the running of the web from one nip to the next nip. It is advantageous that each intermediate roll 3 has one take-out roll 6 tied to it by means of a support (not shown in the figures), so that an intermediate roll 3 and a take-out roll 6 form together a movable roll package and which may also include other auxiliary devices of the intermediate roll 3, such as, for example, a doctor (not shown in the figures).

To enable replacement of the calender rolls 2, 3, 4, the multi-nip calender further includes relief means 7 for relieving the calender rolls 2, 3, 4, preferably for full relief, whereby the nip loads between the roll pairs are zeroed and the calender rolls 2, 3, 4 are separated from one another, which makes it possible to change a single top roll 2, intermediate roll 3 or bottom roll 4 of the calender.

The roll replacement device 8 of the multi-nip calender illustrated in Figs. 1 A, IB, 2A, 2B includes: a frame which is transverse to the machine direction (MD, Machine Direction) parallel to the direction of the web of the paper machine and which comprises vertical parts 81 and a horizontal part 82 between them; a service platform 83 which is arranged and supported between the vertical parts 81 so as to be movable in the vertical direction; and calender roll replacement means 9 for gripping a selectable first intermediate calender roll 3 or the bottom roll 4 or a roll package 3, 6; 4, 6 formed by a calender roll and its auxiliary devices, for detaching selectable first intermediate roll or roll package from the multi-nip calender 1 and for fitting a selectable second intermediate roll or roll package back in the multi-nip calender 1. The roll replacement device 8 moves along a predetermined path forwards and backwards in the machine direction, preferably on support of a base 84 provided with wheels along guide rails 85.

As shown in the figures, the roll replacement device 8 moves backwards and forwards in the machine direction between a home station B shown in Figs. IB and 2B, where the roll replacement means 9 of the roll replacement device 8 support the intermediate calender roll 3 or the bottom roll 4 or the roll package 3, 6; 4, 6 comprising such a roll, detached from the calender 1, and a work station B shown in Figs. 1A and 2A, where the roll replacement device 8 receives the calender roll 3, 4 or the roll package 3, 6; 4, 6 from the calender 1. In the roll replacement device 8 in accordance with the invention, the service platform 10 and the means 9 for replacement of a calender roll, which is a bottom roll 4 or a selectable intermediate roll 3, or a roll package comprising a calender roll, are able to move in the vertical direction independently of each other past each other substantially over the entire height of the frame. Then the means 9 for replacement of a calender roll 3, 4 or a roll package may grip and support the selectable intermediate calender roll 3 or the bottom roll 4 at the neck of the roll axle, advantageously in the immediate vicinity of the end of the roll shell, or at the bearing housing or outside the bearing housing.

With reference to Figs. 2 A and 2B, since the bottom roll 4 of the calender weighs substantially more than the intermediate rolls of the calender, it is advantageous that, for the bottom roll 4 of the calender 1 , the calender roll replacement means 9 are provided with supports 12 for receiving and replacing the bottom roll, which supports are separate from lifting arms 91 and disposed at the foot of the vertical parts 81. Advantageously, the support for receiving and replacing the bottom roll is disposed on or in the base 84 of the vertical part 81 of the roll replacement means, which base is provided with wheels. Then, when the bottom roll 4 is replaced, the lifting arms 91 of the intermediate roll 3 can be lowered to a lower position into or on the base 84, as illustrated in Figs. 2A and 2B.

With reference to Figs. 1A and IB, in an advantageous embodiment of the invention, the means 9 for replacement of an intermediate roll 3 or a roll package 3, 6 in the calender include a pair of lifting arms 91, which are arranged to move, while retaining their position, vertically along the vertical parts 81 of the frame. In that case, it is particularly advantageous in accordance with the invention that the lifting arms 91 are attached to slide parts 93 moving along the vertical parts of the frame, in which connection means, for example, a toothed rack or a toothed wheel or a screw drive, for moving the slide parts 93 along the vertical parts 81 can be arranged between the slide part 93 and the vertical part 81 while, at the same time, the slide surface of the slide part 93 supported against the vertical part supports the lifting arm 91.

Since the take-out rolls 6 are situated outside the vertically arranged intermediate calender rolls 3, the lifting arms 91 are dimensioned to receive, in accordance with the invention, a roll package formed by an intermediate calender roll 3 and its auxiliary devices, which include at least a take-out roll 6 for the web. It is, of course, possible to dimension the lifting arms 91 to receive only a selectable intermediate roll 3 of the multi-nip calender 1. In that case, in particular if the take-out roll 6 is connected to the intermediate calender roll 3 with a support, it may become problematic to arrange support for the take-out roll 6 after detachment of the intermediate roll 3.

In order that the roll replacement device in accordance with the invention might also be used for replacement of still hot intermediate and bottom rolls 3, 4 of the calender 1 without any problems, the means 9 for replacement of a calender roll 3, 4 and/or a roll package additionally include a rotation drive (not shown in the figures) for the intermediate roll 3 detached and placed on support of the lifting arms 91 or for the bottom roll 4 detached and placed on the receiving and replacement support 12 to prevent damage from being caused by the thermal stresses of the calender roll 3, 4. This kind of rotation drive can be advantageously arranged on one or both lifting arms 91 as well as on one or both receiving and replacement supports.

The intermediate calender roll 3 detached from the multi-nip calender 1 and placed on the lifting arms 91 or the bottom roll 4 detached and placed on the receiving and replacement supports 12 or a roll package comprising such a calender roll is intended to be removed from the lifting arms 91 or from the receiving and replacement supports 12 by means of an overhead hall crane 11, and the calender roll 3, 4 or the roll package intended to be installed in the multi-nip calender 1 is intended to be brought onto the lifting arms 91 or onto the receiving and replacement supports 12, respectively, by means of the overhead hall crane 11.

Above, the invention has been described by way of example only; of course, this does not mean that the present invention is limited only to those particular examples described but, as is clear to a person skilled in the art, the invention can be applied, varied and modified within the basic idea and the scope of protection of the invention as defined in the appended claims.

Claims

1. A roll replacement device (8) for a multi-nip calender (1) of a paper machine, which device comprises: a frame which is transverse to the machine direction (MD, Machine Direction) parallel to the direction of the web of the paper machine and which comprises vertical parts (81) and a horizontal part (82) between them; a service platform (83) which is arranged and supported between the vertical parts so as to be movable in the vertical direction; and calender roll (3, 4) replacement means (9, 12) for gripping and detaching a selectable first calender roll as well as fitting back a selectable second calender roll in the calender, and which roll replacement device moves along a predetermined path, preferably along guide rails (85), forwards and backwards in the machine direction, characterized in that the service platform (83) of the roll replacement device (8) and the means (9, 12) for replacement of a calender roll (3, 4), which is advantageously a bottom roll or a selectable intermediate roll, or of a roll package (3, 6; 4, 6) formed by a calender roll and its auxiliary devices, or at least lifting arms (91) included in the replacement means are able to move past each other in the vertical direction, that the replacement means grip the calender roll selectively at the neck or at the bearing housing of the axle of the roll or outside the bearing housing, and that the roll replacement device moves in the machine direction forwards and backwards between a home station (B), where the roll replacement device (8) supports the calender roll or the roll package, and a work station (A), where the roll replacement device receives a selectable first calender roll or the roll package from the calender (1).

2. A roll replacement device as claimed in claim 1, characterized in that the service platform (83) of the roll replacement device (8) and the means (9, 12) for replacement of an intermediate calender roll (3) or a roll package (3, 6) comprising an intermediate roll, advantageously lifting arms (91) for gripping a selectable first intermediate calender roll or a roll package, for detaching selectable first intermediate roll or roll package from the calender (1) and for fitting a selectable second intermediate roll or roll package in the calender, said service platform and replacement means moving vertically on the frame, are movable in the vertical direction independently of each other past each other substantially over the entire height of the frame.

A roll replacement device as claimed in claim 1 and/or 2, characterized in that the means (9) for replacement of an intermediate roll (3) of the calender (1) include a pair of lifting arms (91), which are arranged to move, while retaining their position, vertically along the vertical parts (81) of the frame.

A roll replacement device as claimed in claim 1 to 3, characterized in that the means (9) for replacement of an intermediate calender roll (3) or a roll package (3, 6) comprising an intermediate roll include a pair of lifting arms (91), which are arranged to move, while retaining their position, vertically along the vertical parts (81) of the frame, and that the lifting arms are attached to slide parts (93) moving along the vertical parts of the frame.

A roll replacement device as claimed in any one of claims 1 to 4, characterized in that the lifting arms (91) are dimensioned to receive, as a whole, an intermediate calender roll (3) and a roll package formed by its auxiliary devices, which include at least a take-out roll (6) for the web.

A roll replacement device as claimed in any one of claims 1 to 5, characterized in that the lifting arms (91) are dimensioned to receive a selectable intermediate roll (3) of the multi-nip calender (1).

A roll replacement device as claimed in any one of claims 1 to 6, characterized in that for replacing the bottom roll (4) of the calender (1) the roll replacement device (8) includes a support (12) for receiving and replacement of the bottom roll (4) of the calender (1), which support is disposed at the foot of the vertical part (81), advantageously on or in a base (84) of the vertical part (81) of the roll replacement means (9), said base being provided with wheels.

8. A roll replacement device as claimed in any one of claims 1 to 7, characterized in that the roll replacement device comprises a drive for rotating the calender roll (3, 4) to prevent damage from being caused to the roll by thermal stresses.

9. A roll replacement device as claimed in any one of claims 1 to 7, characterized in that the roll replacement device comprises a drive for rotating the calender roll (3, 4) to prevent damage from being caused to the roll by thermal stresses, and that the rotation drive is arranged on at least one of the lifting arms (91) and advantageously also on at least one of the supports (12) for receiving and replacement of the bottom roll (4).

10. A roll replacement device as claimed in any one of claims 1 to 9, characterized in that the calender roll (3, 4) is intended to be removed from the lifting arms (91) or from the receiving and replacement supports (12) by means of an overhead hall crane (11), and that the calender roll (3, 4) intended to be installed is intended to be brought onto the lifting arms (91) or the receiving and replacement supports (12) by means of the overhead hall crane (11).