JP2004538383A - Press roll and press roll and press cover replacement method therefor - Google Patents

Abstract

A press roll and a method for replacing the press roll and the press cover for the mounting of a flexible press cover on two cover bearing discs with minimal possible effort, ie in the shortest possible time, are provided. .
[Solution]
The present invention relates to a shoe press roll (8) for treating (eg, dewatering or smoothing) a fibrous web, especially a paper or cardboard web. The shoe press roll forms a press slit with the opposing roller (9), said slit extending in the web running direction. The shoe press roll of the present invention comprises a flexible press sleeve (10) fixed at each roller end to a sleeve support disc (11, 12), said sleeve support disc being attached to a fixed support body (13). Mounted rotatably. The press sleeve (10) has an assembly ring (21, 22) on at least one of its two ends, so that the press sleeve can be mounted on a sleeve support disc. The stiffening ring is located inside the outer diameter of the press sleeve.
[Selection diagram] Fig. 1

Description

【Technical field】
[0001]
The present invention relates to press rolls used for treating (eg, dewatering or calendering) fibrous webs, especially paper or cardboard webs.
[Background Art]
[0002]
As is well known, such a press roll, together with the opposing roll, forms a press nip extending in the web running direction. In particular, it is also known that shoe press rolls have a flexible press cover secured at each end of the roll to at least one rotatable cover bearing disc. A stationary support element extends through the interior of the press cover, to which the cover bearing disc is attached. The support element has at least one press element for pressing the press cover against the opposing roll. The flexible press cover includes a plastic, preferably polyurethane, and a stiffener embedded therein. The reinforcement may be formed as a woven fabric. However, what is well known as a laid fabric comprising axially parallel longitudinal filaments and annular filaments woven therein is preferred. The press cover, the cover bearing disc and the support element are restrained in a closed interior, which is sealed from the outside.
[0003]
The invention further relates to a flexible press cover for press rolls and a method for replacing a press cover, ie a method for replacing an old press cover with a new press cover.
[0004]
For the prior art, refer to the following documents.
[0005]
D1: DE 4328505 A1 (PC 05201) specification D2: DE 3546650 C2 (PH 04164A) specification D3: DE 2702362 (PH 10287) specification [Patent Document 1]
DE 4328505 A1
[Patent Document 2]
DE 3546650 C2
[Patent Document 3]
DE 29702362
DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
[0006]
From document D1, it can be seen that the shoe press roll is often positioned below the opposing roll, but is otherwise positioned above the opposing roll. As is well known, after a certain period of operation, the press cover must be removed and replaced with a new press cover. FIG. 5 shows how the pulling of a new press cover using the example of the shoe press roll located at the bottom proceeds. In the example shown, both rollers, a shoe press roll and a sufficiently equal opposing roll, may be supported by a cantilever. As a result, a hose-like flexible press cover can be pulled over the at least one rotatable cover bearing disc on the stationary roll component.
[0007]
According to document D2, the end areas are bent radially inwardly and fastened in order to achieve a liquid-tight connection between each of the end areas of the press cover and one of the cover bearing discs. By means of the element, provision is made to press against the outer end of the cover bearing disc. To facilitate this mounting operation, a number of recesses are provided on each of the two edges of the press cover, between which the recess tongues are retained. This method has been tested in practice. However, the mounting operation has the disadvantage that it takes a relatively long time, and that it is sometimes difficult to achieve the most accurate circular shape of the press cover.
According to document 3, avoiding the deformations described in D2 with respect to the press cover end areas, each of the two press cover end areas maintains its normal cylindrical shape and does not form recesses and tongues. Attempts have been made to get it done. Provision is made to clamp the cylindrical press cover end region between the inner expandable (ie, having an expandable diameter) expanding ring and the outer ring. However, such outer rings are often broken, particularly because it is now more difficult to replace a worn press cover with a new press cover.
[0008]
The invention is based on the object of developing a press roll of the design mentioned at the outset in such a way that the following requirements can be met as far as possible.
[0009]
a) The mounting of the flexible press cover on the two cover bearing discs must be able to be realized with minimal possible effort, ie with the shortest possible time. If this mounting operation is performed inside the paper machine, one must take into account the fact that often only a small amount of mounting space is available at the two ends of the roll.
[0010]
b) The outer peripheral surface of the press cover must be empty or, for example, still free of the fastening elements of the outer ring.
[0011]
c) The most accurate circular shape of the finally mounted press cover must be achievable.
[Means for Solving the Problems]
[0012]
According to the invention, the object is in principle that the press cover has a mounting ring on at least one of its two ends, by means of which the press cover can be mounted on the associated cover bearing disc. This is achieved by: The mounting ring is preferably arranged inside the outer diameter of the press cover, so that the outer peripheral surface of the press cover is still free of any kind of fixing element.
【The invention's effect】
[0013]
A major advantage of the design according to the invention is that a mounting ring (or two mounting rings) can be mounted on a new press cover while the press roll with the old press cover is still in operation. Therefore, the fixing of the mounting ring to the press cover can be performed without receiving any temporal pressure, and the required precision and the subsequent desired circular shape, that is, the exact centering of the finally mounted press cover, are conventionally achieved. It can be realized more easily than the method described in Thus, when the old press cover is removed, the new press cover with the pre-installed mounting ring (or a plurality of pre-installed mounting rings) is pulled, and the cover support is substantially shorter than before. Can be fixed to disk.
It is preferable that the press cover starts from the operator side of the press roll and is pulled in the direction of the drive side end as in the related art. Even if the mounting ring is pre-mounted on only one of the two ends of the press cover, the above-mentioned advantages are still realized to some extent. In this case, it is preferable that one of the mounting rings is previously mounted on the press cover operator side. Also, even if it is desirable to pre-attach the mounting ring to the drive-side end of the press cover under certain circumstances, the stationary position close to the press cover's circumferential path allows the drive-side mounting ring to be pulled. It is necessary to arrange the components so that they can be moved.
Various different embodiments and configurations of the press roll according to the invention are explicitly set out in dependent claims 2 to 12. According to claims 13 to 18, protection for the press cover alone is claimed. This is due to the fact that it may be advantageous to attach the mounting ring to a new press cover (for replacement of a worn press cover) as soon as possible during the production of a new press cover.
Furthermore, claims 19 to 22 claim protection for the method of replacing an old (worn) press cover with a new one. The main concept of this method is that the mounting ring is attached to at least one of the two ends of the new press cover before the old press cover is removed from the shoe press roll for overhaul. The advantage is realized.
BEST MODE FOR CARRYING OUT THE INVENTION
[0014]
The details of the dependent claims and the specific embodiments of the invention are described below with reference to the drawings.
[0015]
FIG. 1 shows a cross section of the paper machine in the region of a shoe press, which comprises a shoe press roll 8 and a counter roll 9.
[0016]
The state shown is a state in which the press is prepared for a new press cover 10 that is pulled over the shoe press roll 8. The shoe press roll 8 is in the form of a radially movable press shoe 14 and has a press element with two rotatable cover bearing disks, namely an operator-side cover bearing disk 11 and a drive-side cover bearing disk 12. It has a stationary support element 13. The stationary support elements are located on the frame 14 on the operator side and on the frame 15 on the drive side.
The system of beams 16, 17, 18 is shown schematically, the outer ends of the beams being connected to each other by at least one vertical tie rod 19. This means that the intermediate part 23 on the operator side can be temporarily removed in order to free up the path for the press cover 10 to be pulled in the direction of the arrow P. Details of the illustrated cantilever device are described in document D1.
[0017]
FIG. 1 shows that the mounting rings 21, 22 have been inserted into each of the two ends of the press cover 10 (prepared to be pulled). After the press cover 10 has been pulled, the mounting rings 21, 22 are fixed to the cover bearing discs 11, 12, as will be described in detail with reference to the following figures.
FIG. 2 shows how the operator-side end of the press cover 10 is fixed to the operator-side cover bearing disc 11 in the final mounted state. Outside the machine, at the end of the press cover, in a known manner, it is formed radially on the inside and can be fixed to the outer end of the mounting ring 21 by means of locking elements 24 and screws 25. Notches are provided. Therefore, it is only necessary that the mounting ring 21 be fixed to the cover bearing disc 11 by screws 26 after the press cover has been pulled.
[0018]
In FIG. 2, the press cover 10 is shown only in a simple form. The reinforcing material embedded in the plastic layer is omitted. The reinforcement can be formed as a woven or laid fabric in a well-known manner. Such a laid fabric is shown in FIG. The raid fabric includes an axially parallel longitudinal filament 31 and an annular filament 32 woven therein. A blind hole 33 is formed in a thick press area. Also in the thicker end region is an additional edge reinforcement 34 in the form of a plurality of additional annular filaments. However, the edge reinforcement may also be realized, for example, by a suitable configuration of thicker annular filaments, additional woven fabrics or plastic layers. As a result, in the circumferential direction, the tensile strength, particularly the tensile stiffness (elastic modulus), of the press cover end region is substantially increased. Thus, clamping of the press cover end region between the two structural elements is no longer necessary. Furthermore, there is no need to form recesses and tongues, and the press cover end regions (as shown in FIG. 2) are not deformed. Instead, the end of the press cover is fixed to the outer peripheral surface of the mounting ring 22. This outer peripheral surface may be cylindrical, or may have a conically tapered interior as shown, or may be provided with a smaller depression. Furthermore, this mounting ring 22 is made of metal or plastic and is inserted into the press cover 10 outside the machine, and the fixing can be achieved, for example, by gluing.
[0019]
In order to fix the mounting ring 22 holding the press cover 10 to the drive-side cover bearing disk 12, the following is provided. That is, the outer peripheral surface of the cover support disk 12 has the protrusion 35. The inner peripheral surface of the mounting ring 22 has a projection from the inside to the outside corresponding to a relatively small inner diameter D to a larger diameter in the axial direction. To screw the mounting ring 22 onto the cover bearing disc 12, a bush 36 is rotatably mounted on the cover bearing disc 12. A nose flange 37 is formed integrally with the inner end of the bush 36, and a radial pin 38 is inserted into the outer end. In the illustrated position of the bush 36, the nose of the nose flange 37 acts on the inner end of the ring 22. As a result of the rotation of the bush 36, the nose can pass the ring 22 in the direction of arrow P when the press cover 10 is inserted. Screws 39 are provided to secure the mounting ring 22 to the cover bearing disk 12 with the press cover 10 by the nose flange 37 described above. It goes without saying that several such arrangements are distributed around the circumference of the cover bearing disc 12.
[0020]
In FIG. 3, it is important that the above-mentioned relatively small inner diameter D of the mounting ring 22 is still somewhat larger than the outer diameter of the stationary support element 13 including the press shoe 14 and also the non-rotating accessories.
[0021]
FIG. 4 shows a simplified alternative of FIG. Here, the mounting ring 22 'has a smooth inner surface (without the protrusion 35). Further, the bush 36 is omitted. The mounting ring 22 'is screwed to the cover bearing disc 12' by a simple stud bolt 45. However, with this design, an inner diameter D 'of the mounting ring 22' that is smaller than in FIG. 3 is generally required. However, some of the means shown in FIGS. 6 and 7 are required in order to allow the mounting ring 22 ′ with its accessories to pass through the stationary support element 13 when the press cover 10 is pulled. May be. In addition, at least one cover bearing disc 12 can be disassembled or at least partially removed to allow the press cover 10 to be pulled or to make the press cover 10 easier to pull. It may be configured as follows.
[0022]
The following are provided for attaching the press cover 10A to the attachment ring 22 '. That is, the mounting ring has an outer peripheral surface that tapers in a cone outwardly. Further, in the press cover end region, the annular filaments 32A and / or 34A are woven with increasing prestress such that the end region also tapers outwardly in a conical manner. Attachment of the press cover 10A to the attachment ring 22 'is performed in a manner similar to attachment of the vehicle tire to the wheel rim.
[0023]
Press cover design 10A having annular filaments 32A, 34A woven under increased prestress in the end region may also be combined with a mounting ring 22 "having a cylindrical outer surface. Such an embodiment may be used. 5, where an attempt is made to achieve the largest possible inner diameter D at the mounting ring 22 ". This is realized here by a mounting ring 22 "having an outwardly projecting flange 27 so that it can be mounted on the cover bearing disc 12 by means of a screw 28. The flange 27 only slightly extends the outer peripheral surface of the press cover 10A. Protrude beyond.
FIG. 6 shows the press cover 10 with the mounting ring 22 ′ inserted in a sectional view of the shoe press roll 8. Furthermore, the stationary support element 13 and the radially movable press shoe 14 can be seen. The press shoe 14 is at the position where the press cover 10 is pulled, i.e., during normal operation, at a shorter distance from the axis of the roll. Also shown are a number of guide strips 40 that are radially movable and extend in a direction parallel to the axial direction, such as the press shoe 14. During normal operation, the guide strip 40 is maintained at a very short distance from the inner peripheral surface of the press cover 10. In the position shown, the guide strip 40 has been retracted to pull the press cover 10. In a similar manner, the oil extraction device 41 can be designed to be movable, and (if necessary) the oil supply device 42 can also be designed to be movable.
[0024]
FIG. 7 shows a modification of FIG. It is assumed here that it is not possible to retract the press shoe 14 to a sufficient extent in the direction of the roll axis in order to pull the press cover (10). Furthermore, the oil extraction device 41 'is rigidly mounted near the working path of the press cover. In this case, provision is made for the two mounting ring segments 44 to be inserted into the press cover 10 rather than the looped mounting ring. Each of these segments 44 extends from less than half of the inner circumference of the press cover from the area of the press shoe 14 to the area of the oil extraction device 41 '.
[0025]
In order to pull the press cover as shown in FIG. 5, the press shoe 14 can be retracted to a sufficient extent from the inner periphery of the press cover. An open mounting ring can be provided which interrupts the area of the oil extraction device 41 '. As an alternative, it is possible to provide a mounting ring which is in the form of a ring, but which can be deformed sufficiently elastically, so that it becomes temporarily elliptical when the press cover is pulled.
[Industrial applicability]
[0026]
The present invention is suitable for press rolls used to process (eg, dewater or calender) a fibrous web, especially a paper or cardboard web.
[Brief description of the drawings]
[0027]
1 shows an opposing roll and a shoe press roll with a new press cover with a pre-mounted mounting ring being pulled.
FIG. 2 shows, in a partial longitudinal section, a possible embodiment of the mounting of the press cover on the cover bearing disc on the operator side.
FIG. 3 shows an embodiment of mounting a press cover to a drive-side cover bearing disk.
FIG. 4 shows an embodiment of mounting a press cover to a drive-side cover bearing disk.
FIG. 5 shows an embodiment of mounting a press cover on a drive-side cover bearing disk.
FIG. 6 is a cross-sectional view of the shoe press roll, wherein some non-rotating components of the cover over the press cover can be mounted at a sufficient distance from the circumferential path of the press cover.
FIG. 7 shows a variant of FIG. 6 with a split mounting ring.
[Explanation of symbols]
[0028]
9 ... Opposing roll 10 ... Flexible press cover 11, 12 ... Cover bearing disc 13 ... Stationary support element 21, 22 ... Mounting ring

Claims (22)

A press roll for forming (eg dewatering or calendering) a fibrous web, in particular a paper or cardboard web, with a counter roll (9) to form a press nip extending in the web running direction, comprising the following features: Has,
a) the press roll comprises a flexible press cover (10) secured to at least one cover bearing disc (11, 12) at each end of the roll;
b) said cover bearing disc is mounted so as to be rotatable on a stationary support element (13), said stationary support element (13) pressing said press cover (10) against said opposing roll (9). Having a press element for
c) the press cover (10) has a mounting ring (21, 22) on at least one of its two ends, so that the press cover can be mounted on the cover bearing disc;
Press roll. The press roll according to claim 1, characterized in that the mounting ring (21, 22) is arranged at least for the most part inside the outer diameter of the press cover. 3. The press roll according to claim 1, wherein the press cover (10) is fixed to an outer end of the mounting ring (21). A press roll according to claim 3, characterized in that at least one of the two ends of the press cover (10) is provided with a notch and a tongue, as is known per se. 3. The press roll according to claim 1, wherein at least one of the ends of the press cover is connected to an outer peripheral surface of the mounting ring (22, 22 '). 6. The press cover (10) according to claim 1, wherein in addition to a conventional reinforcement (31, 32), the press cover (10) has an additional edge reinforcement (34) in at least one of its edge regions. Or a press roll according to item 1. 7. The press roll according to claim 1, wherein the press cover (10) has a drive-side mounting ring (22, 22 ') and an operator-side mounting ring (21). The press roll according to claim 7, wherein the two mounting rings are at least substantially identical. The press roll according to claim 7, characterized in that the drive-side mounting ring (22, 22 ') has a larger inside diameter (D, D') than the operator-side mounting ring (21). Press roll according to claim 7, characterized in that the drive-side mounting ring is interrupted in the area of a component (41 ') fixed near the circumferential path of the press cover (10). . Press roll according to claim 7, characterized in that the drive-side mounting ring is divided into at least two ring segments (44). Non-rotating components (14, 40, 41, 42) near the circumferential path of the press cover (10) for pulling and covering the press cover with at least one mounting ring (22, 22 '). The press roll according to any one of claims 1 to 11, wherein the press roll is movable in an axial direction of the roll. A press cover (10) for press rolls used for dewatering or calendering a moving fibrous web, wherein the press cover (10) having a reinforcing plastic layer has the following features: , Adapted to be mounted on a rotatable cover bearing disk (11, 12) belonging to said press roll,
b) the press cover (10) is characterized in that it has a mounting ring (21, 22) which fits the associated cover bearing disc (11, 12) at least at one of its two ends.
Press cover (10). 14. The press cover according to claim 13, characterized in that the mounting ring (21, 22) is at least largely arranged inside the outer diameter of the press cover. 15. Press cover according to claims 13 and 14, characterized in that it is fixed to the outer end of the mounting ring (21). 16. The press cover according to claim 15, characterized in that at least one of the two ends of the press cover (10) is provided with a notch and a tongue, as is known per se. 15. The press cover according to claim 13 or 14, characterized in that at least one of the ends is connected to the outer end of the mounting ring (22, 22 '). 18. The stiffener according to claim 13, characterized in that it has, in addition to a conventional stiffener (31, 32), an additional edge stiffener (34) in at least one of its end regions. Press cover. A method for replacing an old press cover of a press roll with a new press cover (10) belonging to this press roll, comprising a press cover bearing disk (11) on which the press roll is rotatably mounted on a stationary support element (13). , 12), wherein the press roll comprises the following steps: a) the old press cover is removed with the machine in a stationary state;
b) Thereafter, the new press cover (10) in the form of a hose is pulled over the support element (13) and at least one of the support discs (11, 12), and the support discs (11, 12) Fixed to the
Thereby, it is held inside the machine to which the press roll belongs,
c) on the outside of the machine and before removal of the old press cover, at least one end of the new press cover (19) is equipped with a mounting ring (21 and / or 22). Method. 20. Method according to claim 19, characterized in that after the new press cover has been pulled, the cover ring is connected to an associated support disc (11 or 12). Method according to claim 19 or 20, characterized in that the mounting ring (21 and / or 22) is fixed to the new press cover (10) just before the new press cover (10) is pulled. . 21. The new press cover (10) according to claim 19 or 20, characterized in that the mounting ring (21 and / or 22) is connected to the new press cover (10) as early as during the production of the new press cover (10). Method.