Machine and method for producing a fibrous web

Abstract

The invention relates to a machine for producing a fibrous web (1), comprising a Yankee cylinder (2) and a clothing run (4) with a press roll (5), a piecing means (6) and internal guide means (7), and is characterised in that at least one internal cantilever (8) is arranged within the clothing run (4), and the press roll (5) and all the internal guide means (7) are connected to the internal cantilever (8), wherein the piecing means (6) is connected to the internal cantilever (8) and to the press roll (5). The invention also relates to a method and allows efficient changing of the clothing (3).

Description

[0001] MACHINE AND METHOD FOR PRODUCING A FIBROUS WEB

[0002] The invention relates to a machine for producing a fibrous web, comprising a Yankee cylinder for drying and / or smoothing the fibrous web and a clothing run designed to circulate an endless clothing, wherein the clothing run comprises a press roll, a positioning means, and internal guide means for guiding the endless clothing, the press roll can be placed or pressed against the Yankee cylinder with the positioning means to form a nip, the endless clothing can be guided through the nip between the Yankee cylinder and the press roll, and the internal guide means are arranged within the clothing run in contact with an inner side of the endless clothing. The invention also relates to a method for changing the endless clothing of the clothing run of the machine according to the invention.

[0003] Machine-finished papers (MG papers) are produced on a machine with a Yankee cylinder. The Yankee cylinder typically has a diameter of about 2.5 meters to about 8.5 meters and is made of cast iron or steel.

[0004] Thus, US2784652A discloses a paper machine for producing MG paper with a Yankee cylinder, a first clothing run with a first suction press roll which forms a first nip with the Yankee cylinder in order to transfer a fibrous web from a first felt to the Yankee cylinder, a second clothing run with a second suction press roll which forms a second nip with the Yankee cylinder in order to dewater the fibrous web running through the second nip with a second felt.

[0005] Typically, the machine includes a frame to accommodate the various machine elements, whereby the way in which a covering can be inserted into the machine or the covering path depends heavily on the frame. For example, it may be necessary to first sew the covering into an endless fabric in the machine to create an endless fabric. The use of cantilever beams, i.e.

[0006] Cantilever cranes are known, whereby on a drive side of the machine opposite the driver's side, cantilever girders or cantilever beams are mounted or clamped on one side. In this way, the cantilever beams can absorb loads across the entire width of the machine. When the machine is in operation, the cantilever beams are additionally connected to the driver's side framing via intermediate elements, thereby achieving a much greater load-bearing capacity. To pull in an endless covering, the driver-side connections between the cantilever girders and the driver's side framing are opened or the intermediate elements are removed in order to be able to insert the endless covering through the resulting openings. Furthermore, the guide means for guiding the covering, i.e. guide rollers, tensioning rollers, regulating rollers, must be transferred to separate covering change positions.

[0007] The aim of the invention is a machine with an optimized clothing cycle that enables efficient clothing changes. Clothing changes may be necessary for various reasons, e.g., planned to renew the clothing or replace it with an alternative, or unplanned after an unexpected clothing failure. Changing the clothing results in a downtime of the entire machine and thus a deterioration in machine efficiency or running time, resulting in costs due to lost production output. Optimizing the clothing change therefore directly improves machine availability and profitability.

[0008] This is achieved according to the invention in that one or more inner cantilever beams, ie cantilever beams, are arranged within the clothing run, the press roller and the inner guide means are connected to one or at least one of the inner cantilever beams arranged within the clothing run, wherein the inner cantilever beam(s) is / are designed to receive or support the press roller and all inner guide means of the clothing run and wherein the application means is connected on the one hand to one or at least one of the inner cantilever beams directly or indirectly via inner connecting means and on the other hand to the press roller. A clothing run is delimited by the endless circulating clothing and comprises guide means for guiding the clothing, ieGuide rollers, tensioning rollers, regulating rollers, whereby these are in contact as inner guide means with an inner side of the clothing or as outer guide means with an outer side of the clothing. According to the invention, the clothing run comprises one or more inner cantilever beams, which are arranged within the clothing run, whereby the press roller and all inner guide means are connected to the inner cantilever beam(s). This means that the press roller and all inner guide means of the clothing run are received or carried by the inner cantilever beam(s). The press roller which forms a press nip with the Yankee cylinder is thus a specific embodiment of an inner guide means and is also connected to the one or more inner cantilever beams or is carried by the same. In addition, according to the invention, the application means is on the one hand connected to the one or more inner cantilever beams.connected to at least one inner cantilever beam directly or indirectly via internal connecting means and, on the other hand, to the press roller. The internal connecting means are designed, for example, as beams. Advantageously, the application means is arranged substantially within the covering path. The invention allows for a surprisingly efficient change of the covering. By opening the driver-side connections between the cantilever beams and the driver-side framing or by removing the intermediate elements, a covering can be pulled into or out of the machine. According to the invention, the relocation or removal required in the prior art is no longer necessary.Transferring the guide means into their own covering change positions, whereby the generally largest guide means in the covering path - the press roller - does not require any further manipulation to carry out the covering change, and in particular no separation of the application means from the press roller or the inner cantilever beam or inner connecting means is required.

[0009] Advantageously, the press roller and the inner guide means are connected directly or indirectly to one or at least one of the inner cantilever beams. An indirect connection can be achieved via the inner connecting means arranged substantially within the covering run, wherein the inner connecting means are carried exclusively by the one or more inner cantilever beams. The direct connection allows the press roller and the inner connecting means to be connected directly to the cantilever beam. An indirect connection, i.e. via inner connecting means, can also be used to connect inner guide means or the press roller that are further away from the cantilever beam to the cantilever beam, the inner connecting means being designed as beams, for example. Analogously, the application means is connected either directly to one or at least one of the inner cantilever beams or indirectly, i.e. to the inner connecting means.In this way, an optimal integration can be achieved depending on the number and load-bearing capacity of the available internal cantilever beams and the number of internal guide means to be connected.

[0010] Particularly advantageous is a machine comprising exactly one inner cantilever beam in the covering track. The press roller and all inner guide means are supported by the one inner cantilever beam directly or indirectly via the inner connecting means. This allows for a particularly compact design of the covering track and a particularly efficient covering change, since the connections to the guide-side frame only need to be opened or closed for a single cantilever beam.

[0011] Equally advantageous is a machine in which the press roll is, in particular, a deflection-compensated press roll and forms a marking nip, the endless clothing is a marking fabric, in particular a marking felt, and the marking fabric can be guided through the marking nip between the Yankee cylinder and the press roll. By designing the clothing path with a marking nip, patterns, e.g., lines, can be applied via the marking fabric to the fibrous web guided through the nip.Typically, the machine comprises a first clothing run according to the invention with a first press roll, in particular a deflection-compensated press roll, and a second clothing run according to the invention with a second press roll for forming a marking nip, wherein a first nip of the first clothing run formed between the Yankee cylinder and the first press roll, viewed in a running direction of the fibrous web, is arranged in front of a second nip of the second clothing run formed as a marking nip between the Yankee cylinder and the second press roll. The first clothing run or the first nip allows the fibrous web to be applied or pressed or dewatered against the Yankee cylinder. Between the first nip and second nip, the fibrous web is thermally dried on the Yankee cylinder, wherein the fibrous web then has a suitable dry content in the second nip for marking the fibrous web.Advantageously, the press roller of a clothing run is designed as a deflection-compensated roller.

[0012] Yankee cylinders are known to operate within a pressure range, e.g., between 2 and 10 bar g. The Yankee cylinder itself is a thin-walled machine element. The deformations of the Yankee cylinder, which depend on the operating mode—such as overpressure, centrifugal forces, thermal stresses, and contact pressure—can be optimally compensated for by a deflection-compensated roll, thus achieving uniform contact pressure in the respective nip and reliable production of the fibrous web.

[0013] A favorable embodiment of the invention is characterized in that the press roller (5) can be applied against the Yankee cylinder (2) during operation with a line load of a maximum of 200 kN / m, and preferably a maximum of 120 kN / m. Advantageously, such line loads can still be easily absorbed by a structure with an internal cantilever beam.

[0014] A further advantageous embodiment of the invention is characterized in that the clothing path comprises external guide means arranged outside the clothing path in contact with an outer side of the endless clothing. The outer guide means are connected to a frame of the machine, but not to the inner cantilever beam of the clothing path. The outer side of the endless clothing is in direct contact with the fibrous web in the nip. Advantageously, a greater tensioning path of the clothing can be achieved in a clothing path with external guide means.

[0015] A machine is advantageous wherein the clothing path comprises at least one guide means designed as a tensioning roller and all guide means arranged outside the clothing path are designed as tensioning rollers. Alternatively and equally advantageous is a machine wherein the clothing path does not comprise any guide means, i.e. guide roller, tensioning roller or regulating roller, which is arranged outside the clothing path in contact with an outer side of the endless clothing, wherein the clothing path comprises at least one guide means designed as a tensioning roller and the tensioning roller is arranged inside the clothing path. It has been recognized that a tensioning roller can be moved automatically between end positions. Advantageously, to change the clothing the tensioning roller only has to be moved towards or into the corresponding end position, i.e. in the direction to release the tension from the clothing.This allows for efficient clothing changes without requiring further manipulation of the tension roller or transferring the tension roller to a separate change position. Advantageously, a tension roller is designed as a lever tension roller or a linear tension roller.

[0016] The invention also relates to a method for changing the endless clothing of the clothing run of the machine according to the invention. The method comprises the following steps:

[0017] - Connecting the covering on one side of the covering with a pull-out device

[0018] - Connecting the covering on a drive side of the covering via at least one gripping element to a pulling device, which is arranged in particular on the drive side

[0019] - Pulling out the covering and the at least one gripping element to the driver's side of the machine and out of the machine by means of the pull-out device - Separating the covering from the at least one gripping element

[0020] - Connecting a new covering on the drive side of the new covering via at least one gripping element to the pulling device

[0021] - Pulling the new covering to the drive side and into the machine via at least one gripping element connected to the pulling device.

[0022] The drive side refers to the side of the machine on which the machine's drives are primarily located, with the driver side and drive side forming opposite sides of the machine. The driver side is named after the machine operator's good accessibility to the machine. The method according to the invention allows for particularly efficient clothing changes. For example, the gripping elements connected to the pull-in device arranged on the drive side for pulling in the new clothing are moved from the drive side to the driver side as the clothing is pulled out. This eliminates the need for laboriously moving the gripping elements manually through the machine; in particular, it eliminates the need for the machine operator to walk through the machine.It is particularly advantageous that the method according to the invention allows the non-destructive removal of the used covering from the machine, thus enabling later reuse of the covering. Advantageously, the removal of the covering and the insertion of the new covering are carried out manually and / or by a motor, with the gripping elements preferably being designed as clamps and the insertion device preferably as a winch.

[0023] The invention will now be described by way of example with reference to the drawings.

[0024] Fig. 1 shows a machine according to the invention with a tensioning roller arranged within a clothing run.

[0025] Fig. 2 shows a machine according to the invention with a tension roller arranged outside a clothing path.

[0026] Fig. 3 shows a machine according to the invention with a linear tensioner arranged within a clothing run.

[0027] Fig. 4 illustrates the method according to the invention for changing the endless covering.

[0028] Fig. 1 shows a machine according to the invention for producing a fibrous web 1 with a Yankee cylinder 2, a first clothing run 4, 15 and a second clothing run 4, 16. The clothing run 4, 15, 16 is designed to circulate an endless clothing 3 and comprises a press roll 5 for forming a nip 9 against the Yankee cylinder 2, a positioning means 6 for positioning / pressing the press roll 5 against the Yankee cylinder 2 and internal guide means 7 for guiding the endless clothing 3. The endless clothing 3 of the respective clothing run 4, 15, 16 is guided between the Yankee cylinder 2 and the press roll 5 through the nip 9. By definition, inner guide means 7 are arranged within the covering run 4,15,16, ie within the circulating covering 3, and are in contact with an inner side of the endless covering 3. Accordingly, outer guide means 17 are arranged outside the covering run 4,15,16, ieoutside the circumferential clothing 3, and are in contact with an outer side of the endless clothing 3. According to the invention, an inner cantilever beam 8, i.e. cantilever beam, is arranged within the clothing run 4, wherein the press roller 5 and the inner guide means 7 are connected to the inner cantilever beam 8 directly or indirectly via inner connecting means 11. The inner cantilever beam 8 is designed to receive or support the press roller 5 and all inner guide means 7, i.e. guide rollers, tensioning rollers or regulating rollers, of the clothing run 4. The contact means 6 connects the press roller 5 to the inner connecting means 11 or the inner cantilever beam 8, wherein the inner connecting means 11 as well as the contact means 6 are arranged substantially within the clothing run 4. The contact means 6 is designed, for example, as a hydraulic or pneumatic pressure cylinder or as a press bellows.

[0029] In Fig. 1, the first clothing run 15 is shown as a clothing run according to the invention with a press roll 5 for forming a first nip 9, and the second clothing run 16 is shown as a further clothing run according to the invention with a second, preferably deflection-compensated press roll 5, wherein a marking clothing 14 is guided through the second nip 9, designed as a marking nip 13, between the Yankee cylinder 2 and the second press roll 5, and the first nip 9 is arranged in front of the second nip 9 of the second clothing run 16, viewed in a running direction of the fibrous web 1. In the second clothing run, no guide means 17 are arranged outside the clothing run 4, 16 or in contact with an outer side of the endless clothing 3, wherein the clothing run 4, 16 comprises a tensioning roller 18 which is arranged within the clothing run 4, 16.The tensioning roller 18 of the second clothing run 4, 16 is designed as a lever tensioning roller, but could also be designed as a linear tensioning roller. Fig. 1 also shows the two end positions of the tensioning roller 18 of the second clothing run 16. In the first end position—the upper end position in Fig. 1—the tensioning roller 18 provides maximum tension to the endless clothing 3. In the second end position—the lower end position in Fig. 1—the tensioning roller 18 does not provide any tension to the endless clothing 3 and is selected such that this end position is optimal for changing the endless clothing 3.

[0030] The inner cantilever beams 8, i.e. cantilever supports, are mounted or clamped on one side on the drive side of the machine opposite the driver side and can absorb loads across the entire machine width. During operation of the machine, the cantilever beams 8 or cantilevered are connected or closed to the driver-side frame via intermediate elements 24, whereby a much greater load capacity is achieved. To insert the endless clothing 3, the driver-side intermediate elements 24 between the inner cantilever beams 8 and the driver-side frame are opened or removed in order to be able to insert the endless clothing 3 at the openings thus formed. Fig. 2 shows a machine according to the invention for producing a fibrous web 1 with a Yankee cylinder 2, a first clothing run 4, 15 and a second clothing run 4, 16. In contrast to Fig. 1, the second

[0031] The second clothing run 16 has an outer guide means 17 which, outside the second clothing run 16, is in contact with the outside of the endless clothing 3. The outer guide means 17 is designed as a tensioning roller 18, wherein in the second clothing run 16 shown, all outer guide means 17 are designed as tensioning rollers 18. The tensioning roller 18 is designed as a lever tensioner and is connected to the frame of the machine outside the clothing run 16 - but not to the inner cantilever beam 8. The tensioning roller could alternatively also be designed as a linear tensioning roller. Fig. 2 also shows the two end positions of the tensioning roller 18 of the second

[0032] Clothing run 16 is indicated. In the first - in Fig. 2 - lower end position, the tensioning roller 18 ensures maximum tension of the endless clothing 3. In the second - in Fig. 2 - upper end position, the tensioning roller 18 does not ensure any tension of the endless clothing 3 and thus allows easy retraction of the clothing, making this end position optimal for changing the endless clothing 3.

[0033] Fig. 3 shows a machine according to the invention for producing a fibrous web 1 with a Yankee cylinder 2, a first clothing run 4, 15 and a second clothing run 4, 16. In contrast to Fig. 1, the second

[0034] The second covering run 16 has a tensioning roller 18 designed as a linear tensioner. Fig. 3 also shows the two end positions of the linear tensioner of the second covering run 16. In the first end position - the upper end position in Fig. 3 - the linear tensioner ensures maximum tension of the endless covering 3. In the second end position - the lower end position in Fig. 3 - the linear tensioner does not ensure any tension of the endless covering 3, making this end position optimal for changing the endless covering 3.

[0035] Fig. 4 illustrates the process for changing the endless clothing 3 of the clothing run of the machine according to the invention. In the upper illustration of Fig. 4, the endless

[0036] Covering 3 is shown. The covering 3 is connected on the driver side 19 of the covering 3 to a pull-out device 20 and, via gripping elements 22 on the drive side 21 of the covering 3, to a pull-in device 23 arranged in particular on the drive side 21 of the machine. According to the method, the pull-out device 20 allows the covering 3 to be pulled out to the driver side 19 and out of the machine. When the covering 3 is pulled out of the machine, the gripping elements 22 are also moved to the driver side 19 and out of the machine. The covering 3 is separated from the gripping elements 22 of the pull-in device 23. The lower illustration in Fig. 4 shows the new covering 3 - not yet pulled into the machine - which is connected to the pull-in device 23 on the drive side 21 of the new covering 3 via the gripping elements 22.In the next step, the new covering 3 is advantageously pulled into the drive side 21 and into the machine via the gripping elements 22 connected to the pulling-in device 23. The pulling-out or pulling-in of the covering 3 is carried out manually and / or motorized, wherein the gripping element 22 is preferably designed as a clamp and the pulling-in device is preferably designed as a winch.

[0037] The present invention offers numerous advantages and allows for the design of an effective clothing cycle, enabling efficient clothing changes. Short clothing changeover times enable an improvement in the overall efficiency of the entire machine, improved production output, and improved profitability. In particular, the invention allows for a quick and undamaged clothing change, which is advantageous when clothing, especially marking clothing, is frequently changed.

[0038] Reference symbol

[0039] 1 fibrous web

[0040] 2 Yankee cylinders

[0041] 3 covering

[0042] 4 Stringing run

[0043] 5 Press roller

[0044] 6 mooring devices

[0045] 7 Internal leadership tools

[0046] 8 Inner cantilever beam 11 Inner connecting elements

[0047] 13 Marking nip

[0048] 14 Marking covering

[0049] 15 first stringing run 16 second stringing run

[0050] 17 external guide means

[0051] 18 tension roller

[0052] 19 Guide page

[0053] 20 Extractor 21 Drive side

[0054] 22 gripping elements

[0055] 23 Retraction device

[0056] 24 intermediate elements

Claims

Patent claims 1 . A machine for producing a fibrous web (1), comprising a Yankee cylinder (2) for drying and / or smoothing the fibrous web (1) and a clothing run (4) designed to circulate an endless clothing (3), wherein the clothing run (4) comprises a press roll (5), a positioning means (6), and internal guide means (7) for guiding the endless clothing (3), the press roll (5) being adapted to be placed or pressed against the Yankee cylinder (2) with the positioning means (6) to form a nip (9), the endless clothing (3) being adapted to be guided through the nip (9) between the Yankee cylinder (2) and the press roll (5), and the internal guide means (7) being arranged within the clothing run (4) in contact with an inner side of the endless clothing (3), characterized in that one or more inner cantilever beams (8), i.e. cantilever beams, are arranged within the clothing run (4). is orthe press roller (5) and the inner guide means (7) are connected to one or at least one of the inner cantilever beams (8) arranged within the clothing run (4), wherein the inner cantilever beam(s) (8) is / are designed to receive or support the press roller (5) and all inner guide means (7) of the clothing run (4), and wherein the application means (6) is connected on the one hand to one or at least one of the inner cantilever beams (8) directly or indirectly via inner connecting means (11) and on the other hand to the press roller (5).

2. Machine according to claim 1, wherein the application means (6) is arranged substantially within the clothing run (4).

3. Machine according to one of the preceding claims, wherein the press roller (5) and the inner guide means (7) are connected directly or indirectly to one or at least one of the inner cantilever beams (8) via the inner connecting means (11) arranged substantially within the clothing run (4).

4. Machine according to one of the preceding claims, wherein the inner connecting means (11) are carried exclusively by the one or more inner cantilever beams (8).

5. Machine according to one of the preceding claims, wherein the machine comprises exactly one inner cantilever beam (8) in the clothing run (4).

6. Machine according to one of the preceding claims, wherein the press roller (5) is in particular a deflection-compensated press roller (5) and forms a marking nip (13), the endless clothing (3) is a marking clothing (14), in particular a marking felt, and the marking clothing (14) can be guided through the marking nip (13) between the Yankee cylinder (2) and the press roller (5).

7. Machine according to one of the preceding claims, wherein the machine has a first clothing run (15) with a first press roll (5), in particular a deflection-compensated press roll, and a second clothing run (16) with a second press roll (5) for forming a marking nip (13), wherein a first nip (9) of the first clothing run (15) formed between the Yankee cylinder (2) and the first press roll (5) is arranged, viewed in a running direction of the fibrous web (1), in front of a second nip (9) of the second clothing run (16) formed as a marking nip (13) between the Yankee cylinder (2) and the second press roll (5).

8. Machine according to one of the preceding claims, wherein the press roller (5) can be applied against the Yankee cylinder (2) with a line load of maximum 200 kN / m and preferably maximum 120 kN / m during operation.

9. Machine according to one of the preceding claims, wherein the clothing run (4) comprises outer guide means (17) arranged outside the clothing run (4) in contact with an outer side of the endless clothing (3).

10. Machine according to one of the preceding claims, wherein the clothing track (4) comprises at least one guide means (17) designed as a tensioning roller (18) and all guide means (17) arranged outside the clothing track (4) are designed as a tensioning roller (18).

11. Machine according to one of claims 1 to 8, wherein the clothing run (4) does not comprise a guide means (17) which is arranged outside the clothing run (4) in contact with an outer side of the endless clothing (3), wherein the clothing run (4) comprises at least one guide means (17) designed as a tensioning roller (18) and the at least one tensioning roller (18) is arranged inside the clothing run (4).

12. Machine according to claim 10 or 11, wherein the tensioning roller (18) is designed as a lever tensioning roller or linear tensioning roller.

13. Method for changing the endless covering (3) of the covering run (4) of the machine according to one of claims 1 to 12, comprising the steps: - connecting the covering (3) on a guide side (19) of the covering (3) to a pull-out device (20) - Connecting the covering (3) on a drive side (21) of the covering (3) via at least one gripping element (22) to a pulling device (23), which is arranged in particular on the drive side (21). - Pulling out the covering (3) and the at least one gripping element (22) to the driver's side (19) of the machine and out of the machine by means of the pull-out device (20) - Separating the covering (3) from the at least one gripping element (22) - Connecting a new covering (3) on the drive side (21) of the new covering (3) via the at least one gripping element (22) to the pulling device (23) - Pulling the new covering (3) towards the drive side (21) and into the machine via the at least one gripping element (22) connected to the pulling-in device (23).

14. The method according to claim 13, wherein the at least one gripping element (22) is designed as a clamp.

15. Method according to claim 13 or 14, wherein the retraction device (23) is designed as a winch and the extension or retraction is carried out manually and / or motorized.

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