EP4667652A2

EP4667652A2 - Adjustment system for a suction roll of a fiber web machine and a suction roll equipped with an adjustment system

Info

Publication number: EP4667652A2
Application number: EP25182217.7A
Authority: EP
Inventors: Illya SARVI; Timo KARONEN; Heikki Kettunen; Upendra NAKHATE; Seppo K PARVIAINEN; Joni PIIPONNIEMI
Original assignee: Valmet Technologies Oy
Current assignee: Valmet Technologies Oy
Priority date: 2024-06-20
Filing date: 2025-06-12
Publication date: 2025-12-24
Also published as: CN121183613A; FI131692B1; FI20245796A1; EP4667652A3

Abstract

The invention relates to an adjustment system for a suction roll of a fiber web machine. The adjustment system includes an actuator (25) connected to a power input (32). In addition, the adjustment system is arranged to be placed inside a suction roll (10) and connected to a movable end deckle (14) included to the suction roll (10) for displacement the end deckle (14). The adjustment system further includes a rod (33) to be connected to the actuator (25). In addition, the rod (33) is arranged to extend outside the suction roll (10) for manual displacement the end deckle (14) with mechanical actuating means (34) instead of the actuator (25). The invention relates also a suction roll equipped with an adjustment system.

Description

The invention relates to an adjustment system for a suction roll of a fiber web machine, which adjustment system includes an actuator connected to a power input and arranged to be placed inside a suction roll and connected to a movable end deckle seal included to the suction roll for displacement the end deckle. The invention relates also to a suction roll equipped with an adjustment system.
The fiber web machine has different suction rolls. The suction roll has a perforated shell with a suction box inside. At least one suction zone is arranged in the suction box, where the vacuum effect of the suction box extends through the holes in the shell to the surface of the shell. The suction zone is delimited by seals that extend to the inner surface of the shell. More specifically, the suction zone is delimited by two axial seals, between which end deckles are arranged. In order to adapt the width of the suction zone to each production situation, the end deckles are adjustable. In other words, the position of both end deckles can be adjusted in the axial direction of the suction roll. For this, the suction roll includes an adjustment system.
US patent 3395073 shows an adjustment system in which end deckles are moved with fluid-powered cylinders. The piston rods of the cylinders fitted inside the suction roll are mechanically connected to the end deckles. Mechanical connections cause an oblique load on the end deckles. In addition, the cylinders require a lot of installation space and fluid leaks are harmful to the operation of the suction roll and the production of the fiber web machine. The adjustment accuracy of the fluid-powered cylinder is also weak, and there must be constant pressure in the cylinder to keep the end deckle in place. In addition, the current position of the end deckle is uncertain.
It is an object of the invention is to provide a new type of adjustment system for the suction roll of a fiber web machine, which is more accurate and reliable than before. The characteristic features of the adjustment system according to this invention are stated in the accompanying claim 1. Another object of the invention is to provide a novel suction roll which has improved adjustment properties. The characteristic features of the suction roll according to this invention are stated in the accompanying claim 12. The adjustment system according to the invention is suitable for use with various suction rolls and end deckles. The control system works precisely and reliably without the problems that occur in known technology. In addition, the components of the control system are durable, and the location of the end deckle is known precisely at all times. In addition to accuracy, the adjustment is fast and can even be done remotely. There is also a backup option in case of disturbances.
The invention is described below in detail by referring to the enclosed drawings which illustrate some of the embodiments of the invention, in which

Figure 1: shows the press position of the fiber web machine, where the suction roll is equipped with an adjustment system according to the invention,
Figure 2a: shows a different suction roll in cross-section,
Figure 2b: shows the adjustment system according to the invention fitted into the suction roll viewed in the machine direction,
Figure 2c: shows the support of the rod seen from the side,
Figure 3a: shows the support of the rod seen from the front,
Figure 3b: shows the deck of the suction box of the suction roll together with the end deckle.

Figure 1 shows an example position of the fiber web machine, where a suction roll 10 is in nip contact with a press roll 11. In the nip, water leaves the fiber web and moves to the holes of the suction roll's shell, more generally speaking, to the open surface of the suction roll. The transfer of water is enhanced by the negative pressure effect, which is created by a suction box 12 fitted inside the suction roll 10. The negative pressure is created in the suction box by some suitable device, which is usually placed outside the suction roll. With one or more axial seals 13, a suction zone 15 with a negative pressure effect can be arranged in the area of the nip or in addition also before the nip. The suction zone can have one or more suction sectors or suction chambers. The suction zone is also delimited by end deckles 14, of which there is at least one at each end of the suction roll. In use, the end deckle includes a seal holder and a sealing strip. After the suction zone 15, the water usually leaves the open surface of the suction roll by gravity. The suction roll can also be used for web control, such as guiding the fiber web to follow the desired fabric.
Figure 2a shows another type of suction roll 10 of the fiber web machine. Generally speaking, the suction roll 10 includes a rotatably supported perforated shell 16 and a suction box 12 fitted inside the suction roll 10. One large shell can have up to a million holes 17. The suction roll 10 in Figure 2a has two suction zones. The axial seals 13 are fitted to a holder 18 and they usually have load hoses 19 for pressing the axial seals against the inner surface of the shell 16. The end deckle 14 is between the axial seals 13 in such a way that the ends of the seal holder of the end deckle are adapted to match the sides of the axial seals. In the direction of rotation of the suction roll, there is usually a thick last axial seal, acting as a kind of silencer when the holes start to fill with air again after the suction zones.
The current suction box 12 shown in Figures 2a and 2b has a plate structure and has a deck 20. In this case, the suction box is light, but rigid. There are openings in the deck, so that the negative pressure led to the suction box extends to the suction zone delimited by seals and from there through the perforated shell to the fiber web. The openings 21 can be seen in Figure 3b. In practice, therefore, the vacuum of the suction box sucks water into the holes of the shell and makes the fiber web follow the desired fabric. In Figure 3b, the axial seals 13 with their holders 18 are supported on the deck 20. Correspondingly, sliding surfaces 22 for the end deckle 14 are machined at the ends of the suction zone. The sliding surface is precisely machined into the base material of the deck and the end deckle slides along the sliding surface.
The invention is directed to an adjustment system for the suction roll of a fiber web machine. As described above, the suction roll 10 includes a movable end deckle 14. In practice, the end deckle 14 consists of a seal holder 23 curved according to the deck 20 and a sealing strip 24 fitted to it. For example, the height of the seal holder can be 80 mm with the sealing strip extending 5 mm outward. In this case, the end deckle covers the distance between the sliding surface and the shell.
In Fig. 2b, the perforated part of the shell 16 of the suction roll 10 is shown with dotted lines, whereby the contours of the suction box 12 installed inside the shell 16 are visible. The axial seal 13 is only shown partially. A flanged shaft 26 with bearings 27 is bolted to both ends of the shell 16. The flanged shaft has a central hole through which the negative pressure is led from the suction connection 28 on the operating side of the suction box. There is also a gear 30 at the end of the drive side, to which a drive is connected via an operating pin 31. Through the central hole, the lubrication jets of axial seals and the load air of the seals, as well as other outlets, are led. The connections of these are assembled in the head plate 29 at the end of the tending side. The suction openings on the deck of the suction box are limited by axial seals 13 together with end deckles 14, so that the suction width of the formed suction zone can be adjusted. For maintenance, the suction roll is removed from the fiber web machine. During maintenance, at least the flanged shaft 26 on the tending side is removed from the shell 16 and the suction box 12 supported by the roller 52 is pulled out from the inside of the shell 16.
In general, the width of the fiber web is maximized with the fiber web machine. If production conditions or product quality change, the width of the fiber web may change, in which case an adjustment system for the end deckles is needed. In practice, the end deckle is placed exactly in line with the edge of the fiber web. With the adjustment system according to the invention, the end seal can be obtained in the desired position with millimeter accuracy.
The adjustment system includes an actuator 25 connected to a power input 32. The actuator is a component of a machine that produces force, torque, or displacement, usually in a controlled way, when an electrical, pneumatic, or hydraulic input is supplied to it in a system. The actuator converts such an input signal into the required form of mechanical energy. The actuator is arranged to be placed inside a suction roll 10, like in Figure 2b. In addition, the actuator 25 is connected to the movable end deckle 14 included to the suction roll 10 for displacement the end deckle 14. Then the position of the end deckle is adjusted. According to the invention, the adjustment system further includes a rod 33 to be connected to the actuator 25. In addition, the rod is arranged to extend outside the suction roll 10 for manual displacement the end deckle seal 14 with mechanical actuating means 34 instead of the actuator 25. In other words, now there are two different ways to be used to adjust the very same end deckle. In practice, the actuator with the power input is the primary way for displacement the end deckle while the mechanical actuating means are as backup. The invention relies on the actuator to move the end deckle, while retaining the possibility of manual adjustment.
Advantageously, the adjustment system includes a sensor 35 for determining the axial position of the end deckle 14. In this way, the current position of the end deckle is always known, and it can be adjusted as desired if needed. In Figure 2b, the left side end deckle 14 is it innermost position. Respectively, the right side end deckle 14 is it outermost position. In addition, only the power input 32 and the rod 33 of the right side end deckle 14 is shown in Figure 2b.
Various sensors may be used, and its position may vary. In the shown embodiment the sensor 35 is included in the actuator 25. The sensor detects the position of the piston and then the position of the end deckle is known when the geometry and dimensions are known. In other word, the actuator also indicates the current position of the end deckle. In this way it is possible to fully automate end deckle adjustment.
As shown in Figures 2b and 3b, the end deckle is on top of the deck 20. Here the actuator 25 is situated on the opposite side of the deck 20 than the end deckle 14. Inside the suction box there is plenty of room for the actuator and the rod too. There is a short connecting bar 36 fixed to the support of the end deckle. To this connection bar is attached both the actuator and the rod. This means that the rod will move as much as the piston of the actuator. In Figure 3a there are three connecting bars 36. In practice, there are at least two connecting bars 36. In this way, the end deckle moves in a straight line. Advantageously, the outer end of the rod 33 has a scale 37. In this way the position of the end deckle can be checked by seeing from the tending side while the sensor tells also the same. So, there are doubled positioning means and information means, i.e. both electronically and with the scale in the rod.
The inner end of the rod is fixed to the connection bar. The outer end comes out of the suction roll. Here the rod 33 has a support 38 to be fixed to the suction roll 10 and allowing axial movement of the rod 33. In this way the rod may move back and worth, while the actuator moves the end deckle.
Figures 2c and 3a shows the support 38 above mentioned. The support 38 is fixed to the head plate 29 of the suction roll 10, so it is stationary. The support 38 has a groove 39 for the head plate 29. The rod can slide inside the support. This is the normal situation when the actuator is used to displace the end deckle. In an exceptional situation, when the primary system is out of order, the mechanical actuating means are used. As the mechanical actuating means 34 the outer end of the rod 33 has an outer thread 40 while the support 38 has a rotary head 41 with an inner thread 42 corresponding to the outer thread 40, and a key slot 43 for manual displacement of the end deckle seal 14. In the normal situation, the rotary head is replaced with a non-rotary sliding head. The combined structure is quick and easy to put into operation. Then with the suitable hand tool the rotary head is rotated and thereby the rod is pushed or pulled by means of the threads. In this way the position of the end deckle is changed.
One advantageous actuator 25 is a water hydraulic cylinder 44, which is self-locking. Minor water leaks will not harm the suction roll or the fiber web. In addition, when the self-locking cylinder is used, continuous pressure is unnecessary which saves energy. Here, the power input 32 includes a control cabin 45 including a control valve 46 connected with pipes 47 to the actuator 25 and a source P of pressurized water. With these simple components the end deckle can be moved quickly and easily. The control cabin also includes an indicator 48 connected to the sensor 35 by a wire 49. Thus, the position of the end deckle is visualized and can be seen without going to the suction roll.
The pressure on pipes keeps the cylinder locked. Before using the mechanical actuating means 34, this pressure in released. For this, the pipes 47 is equipped with valves 50 for depressurizing the actuator 25 for manual adjustment. After this, the rotary head is installed to the support and rotated with the tool to move the end deckle.
With the actuator and the control cabin it is easy to adjust the position of the end deckle accurately. Advantageously, the control cabin 45 is connected to a remote control system 51 of the fiber web machine. In this way, the adjustment is done from a control room at the mill or somewhere else. The adjustment can be automated. Then the position of the end deckles will be adjusted on the basis of the width of the fiber web or some other value automatically.
In practice, the suction roll 10 has a movable end deckle 14 at both end wherein both end deckles 14 has the adjustment system of their own. In other words, both end deckles have their own independent adjustment system. In practice, the position of the end deckles can be adjusted independently of each other. The system also includes a possibility to run a cleaner to clean the mechanism by running the cleaner during shutdown or break.
The adjustment systems may be upgraded to the suction rolls now in use. The actuator is powerful and easy to use even in high vacuum and extreme temperatures. The rod will slide smoothly inside the support and jamming issues are avoided. The system may operate in an automatic mode and manual mode one at a time.

Claims

Adjustment system for a suction roll of a fiber web machine, which adjustment system includes an actuator (25) connected to a power input (32) and arranged to be placed inside a suction roll (10) and connected to a movable end deckle (14) included to the suction roll (10) for displacement the end deckle (14), characterized in that the adjustment system further includes a rod (33) to be connected to the actuator (25) and arranged to extend outside the suction roll (10) for manual displacement the end deckle (14) with mechanical actuating means (34) instead of the actuator (25).
Adjustment system according to claim 1, characterized in that the adjustment system includes a sensor (35) for determining the axial position of the end deckle (14).
Adjustment system according to claim 2, characterized in that the sensor (35) is included in connection with the actuator (25).
Adjustment system according to any of claims 1 - 3, characterized in that the outer end of the rod (33) has a scale (37).
Adjustment system according to any of claims 1 - 4, characterized in that the rod (33) has a support (38) to be fixed to the suction roll (10) and allowing axial movement of the rod (33).
Adjustment system according to claim 5, characterized in that as the mechanical actuating means (34) the outer end of the rod (33) has an outer thread (40) while the support (38) has a rotary head (41) with an inner thread (42) corresponding to the outer thread (40), and a key slot (43) for manual displacement of the end deckle seal (14).
Adjustment system according to any of claims 1 - 6, characterized in that the actuator (25) is a water hydraulic cylinder (44), which is self-locking.
Adjustment system according to claim 7, characterized in that the power input (32) includes a control cabin (45) including a control valve (46) connected with pipes (47) to the actuator (25) and a source (P) of pressurized water.
Adjustment system according to claim 8, characterized in that the pipes (47) is equipped with valves (50) for depressurizing the actuator (25) for manual adjustment.
Adjustment system according to claim 8 or 9, characterized in that the control cabin (45) is connected to a remote control system (51).
Suction roll equipped with an adjustment system, characterized in that the adjustment system is an adjustment system according to any of claims 1 - 10.
Suction roll according to claim 11, characterized in that the suction roll (10) has a movable end deckle (14) at both end wherein both end deckles (14) has the adjustment system of their own.
Suction roll according to claim 12, characterized in that the adjustment systems are independent from each other.
Suction roll according to any of claims 11 - 13, characterized in that the suction roll (10) has a suction box (12) having a deck (20), and the actuator (25) is situated on the opposite side of the deck (20) than the end deckle (14).
Suction roll according to claim 14, characterized in that the actuator (25) is connected to the end deckle (14) at least with two connecting bars (36).