FI119560B - A system on a web forming machine for guiding the web in connection with the groove roll - Google Patents

Description

119560 SYSTEM. WITH A BRAINING MACHINE TO CONTROL A CAMERA WITH A CARRIER ROLLER

The invention relates to a system for guiding a web with a web forming machine 5, which has a surface structure with grooves and the grooves are open only to the outer surface of the groove roll and the runner component includes a runnability component.

Many different drying parts of web forming machines are known in the art, some of which utilize double-wire and / or some single-wire threads. The free strokes of the twin-wire feeder are prone to fluttering, which causes runnability problems, especially when the paper is still relatively moist and thus of low strength. Indeed, in recent years, the use of single-wire exports in which the web has been supported by a drying group on a drying wire has begun to increase. The wire presses the web against the heated surfaces of the drying cylinders. On the pivoting rollers, the wire is against the surface of the pivoting cylinders, and the web is on the other surface of the 20 wire.

. , In the prior art single wire drawings, the wire and • · · t · »* web come from a drying cylinder to a turning cylinder in a common Φ · * • · straight run, forming a closing gap between the drying wire and the turning cylinder. The web and cylinder surface moving toward that pile create excess pressure in the pile through their boundary layer flows. Overpressure in the quilt • · '* ·· * causes a differential pressure across the wire supported web, causing runnability problems. Increasing line speeds add more pressure · · • »: ** Overpressure problems for 30 closing cams. The rotating rollers • * · * ... · transfer sufficient web to the drying cylinder to form a ·: »·· opening. There is a pocket space, ** '♦, which is the pocket space defined by the parallel drying cylinders, between them ···. *, The swivel cylinder and the drying wire.

In the art, attempts have been made to eliminate the problem of a closing kid by means of a suction roller and various vacuum boxes and a combination of 119560 2 rollers and suction boxes. In the case of old slow machines with speeds below 800 m / min, when moving to single-wire export, runnability problems were first reduced by grooving the surface of the lower cylinder with about 5 mm narrow 5 mm grooves. As the velocities increased close to 1000 m / min to the lower cylinder or similar conventionally grooved roll, a runnability component was added, the suction of which was sought to extend into and through the grooves in the wire coverage area around the roll. The dimensions are still used for conventionally grooved rollers and 10 VAC rolls with 5mm narrow and 4mm shallow. The heels between the grooves are typically about 14 mm wide. However, it has been difficult to solve problems in an energy-efficient way. In addition, the need for energy to stabilize the web has increased significantly as machine speeds increase. One solution to the problems is disclosed in Applicant's patent application FI20031461, which discloses a groove roll of a paper or board machine comprising a central axis and a grooved surface structure around it. There is contact between the surface structure and the central axis so that a substantially closed structure is formed. ajettavuuskom with the roll-nent, where, for example, the trailing suction * · enhance the effect of the closing gap on the side of φ opens, on the other hand the impact jaw or the closing gap of the aligned • * blowing enhance the collision and flow • · can be used.

• · u «· • · .. .. .. 25 25 • Ψ

It is an object of the present invention to provide a system for reducing the amount of energy used to create vacuum in a web forming machine. Features of the present invention are that the runnability component includes at least one passive zone in the transverse direction of the web forming machine. .

4 4 4

By a forming machine, as used herein, ·); paper, board, tissue and pulp machines, there are many groove rolls, 4 4 4 · through which the web passes. The web can pass through groove rolls * 4 4 35 unsupported or supported by wire. The groove rollers for guiding the web include a surface structure with grooves. The grooves in the surface structure 119560 3 are open only to the outer surface of the groove roll. The groove roller may be axially known in the art by means of axle pins, a central axis or a stationary shaft having a grooved sheath adapted to rotate. Hereby, the boundary layer flow 5 carried by the roll and the web / wire is utilized by providing a vacuum that holds the web in contact with the groove roll. The grooved surface structure creates a vacuum applied to the web by controlling radial forces. The grooves are preferably of the length of the groove roll revolution, but it is possible to make an ascending groove. The ascending groove io can be implemented in a continuous manner over the entire size of the groove roll. On the other hand, there may be several ascending grooves, for example ascending grooves extending from the center to the edges of the groove roll. The track roller includes a runnability component. Surprisingly, the runnability component includes at least one passive zone in the transverse direction of the forming machine. The passive zone is such that no air is sucked in or blown into it. By air, more broadly is meant gaseous media moving on a paper machine, such as air containing water as a vapor. The passive zone amplifies the vacuum formed by the groove roll, i.e., the pressure difference across the web 20, by controlling the flows and creating surfaces that limit the propagation of pressure. In other words, the passive zone allows for the production of vacuum without external suction or • · * .. C blowing means. The passive zone is thus a passive • ·. ** 1 at all times, whereby no suction or • · · · * 25 flow flows are introduced at any time. The runner- • ♦ • * ♦ component of the passive zone has a remarkable effect on the groove roll performance.

«· '· *** When the runnability component is inactive, it is also economically cheaper to manufacture it. In addition, a significant reduction in energy consumption is essential. The runnability component with 30 passive zones in accordance with the invention allows *: ** to list the placement of the groove roll also in new targets.

• In one embodiment, the runnability component consists of a plurality of zones in the lateral direction of the forming machine, some of which are subjected to external vacuum. In other words, some of the zones are aspirated to form a vacuum. Air can also be blown into these active zones 4119560 to form a vacuum by ejector action. Here, too, the active zones are subjected to external vacuum. In turn, some zones are inactive. The actively underpressed zones 5 achieve higher vacuum in part of the groove roll. These zones / which have a higher vacuum can be used, for example, to assist in the export of the neckline. Such a zone can be located anywhere on the groove roll, since the head-export ribbon can be formed on the edge or center of the machine 10 laterally of the forming machine. Preferably, the zones to which external pressure is applied are at the edges of the forming machine, since they can be used in addition to threading at the edge to prevent flapping of the edges.

In another embodiment, the groove roll is a pivot cylinder. With the groove roller, the passive runner component can be placed in a pocket where the removal of the overpressure on the pivoting side of the pivoting cylinder has required considerable venting by the runner components.

20

In a third embodiment, the first side of the pivoting • cylinder, which enters the web into the pivoting cylinder, has a close fitting. On the other side of the turning cylinder from which the web • ·; leaves the pivoting cylinder, has a gaping opening. The runner com- ponent 25 is adapted to be shaped such that the channel extending to the opening runner is substantially «· * · open away from the pivoting distance along the entire runner component.

,, This design creates flow conditions that help stabilize the wire in the opening of the wire.

In a fourth embodiment, both ··· sides of the swivel cylinder have drying cylinders having, ·. : Throughout, the wire is adapted to be exported as a single wire export. Raina • ··. ·. : is exported from a drying cylinder to a turning cylinder as a short export * · ** 35 having a length of 80 to 600 mm, preferably 100 to 350 mm. In short exports, the drying cylinders and swivel cylinders 119560 5 are positioned close to each other, thereby making the drying section of the forming machine more compact. This short export requires efficient means of producing a negative pressure, since the pressure difference can only be offset over the web and the wire in only 5 short distances. When a rigid component with a passive area is used for short exports, the pressure level required for short exports is achieved with low energy and thus at low cost.

In a fifth embodiment, the web is inclined to a groove roll of less than 120 °, preferably less than 30 °. The angle may vary with different groove rolls so that larger contact angles can be used for exports with fewer rolls, and smaller contact angles for long rolls with multiple rolls (more than 3 pieces). This contact angle is used, for example, on the blowing section, and the lateral angles of the successive groove rolls can vary significantly.

In a sixth embodiment, the passive zone of the runnability component has a vacuum of at least 500 Pa, preferably 800 Pa, in the pocket space of the single wire entry. Smaller • • * ..! they fit into the last drying groups of the drying section. In other words, • ·. ** 1, at the beginning of the drying section, a larger pocket space is required at the beginning of the drying section than at the end of the drying section. The production of this vacuum with suction equipment requires a large investment in suction equipment. In addition, the suction means require significant energy.

In prior art systems, the pocket spaces have a vacuum of 100 - - · 300 Pa. In addition, in the prior art it has been possible to · · · · ··· * 30 separate a separate zone of higher vacuum, with suction *: **: applied only to a few centimeters wide friction in the region of the kidney. The system according to the invention ·. Thus, we can simultaneously save energy and • i · • ·, ·. ; higher vacuum in the pocket space of the single wire outlet, with the runner component, as the prior art runner components apply a high vacuum only to the opening of the cylinder 119560 6. In turn, higher vacuum levels throughout the pocket space allow for greater runnability and control of web properties, such as shrinkage.

5

The invention will now be described in detail with reference to the accompanying drawings illustrating some embodiments of the invention, wherein: Figure 1 illustrates a system for guiding a web with a web forming machine in connection with a groove roll; Figure 2a illustrates a sealing means used in the system the sealing means used in the system, which is a double row comb, viewed from the end of the groove roll,

Figure 3 shows a system according to the invention in a single wire connection, Figure 4a shows a system according to the invention with a runnability component, • ·

Figure 4b shows the runnability score ·. ··· of the system according to the invention. ponentilla, • · ···:. ·. Fig. 4c shows the runnability command of the system according to the invention. With 25 subscribers, and · ··

Fig. 5 illustrates a system according to the invention with a vertical overflow section.

aa * · aa * ... Figure 1 shows a system 10 according to the invention for guiding web 28 • a • ♦ *! * 30 with web forming machine 12 in connection with groove roll 12.

a * “* · The groove roll 12 has a central axis 14 and a grooved surface structure 16, ·· ♦:., 5 between which is in contact to form a substantially closed structure a i, in which the grooves are open only outside the groove roll.

• a: The track roll 12 includes a runnability component 18 which includes at least one passive zone 22 in the transverse or width direction 20 of the forming machine 22. In the passive zone, 119560 provides no suction or blowing from the outside. The suction effect of the runner component passive zone is based on the interaction between the runner component passive zone and the groove roll. The passive zone is thus inactive all the time, whereby no suction / blowing flow is introduced into it at any time.

In the system of the invention shown in Figure 1, the runnability component 18 consists of a plurality of zones 24 in the lateral direction of the forming machine. Some of the zones are subjected to underweight from the outside. The active zones 26, i.e. the zones to which the negative pressure formed by the external means is applied, are at the edges of the groove roll 12 to prevent fluttering of the edges 30 of the web 28 supported by the wire 29 in connection with the groove roll 12. The widths α of the active zones 26 are preferably 10 to 100 cm, preferably 20 to 60 cm. For example, when the forming machine itself is 10 m wide, only a small portion of the width forming direction of the forming machine is externally generated under pressure. In the width direction of the web forming machine, 75 to 99%, preferably 90 to 98% of the web forming machine is covered by a passive zone 20. In addition, in active zones, negative pressure generated by external; * · * · vacuum generating means may be coupled • · *. *. off when the machine is running. However, if fluttering occurs at the edge of the web, active zones «· *: can be maintained. In addition, active • t * ·· ♦ * on the edges: ·. 25 zones can be used during threading to insert the thread • 9 ·, ···. The zone used to carry the headband may also be in the center of the machine. The passive zone may therefore consist of more than one part. A plurality of zones allow optimum vacuum to be applied at each widthwise position of the • • * V 30 drawing machine.

• · ···

In the system 10 according to the invention shown in Fig. 1, a sealing member 32 is provided between the runnability component 18 and the groove roller 12. The sealing member * · 35 can be, for example, a mechanical counter thread or sealing jet. The sealing shower may also be a passive component of the runnability component. A sealing shower does not create a pressure difference ajettavuuskom-between the component and its exterior, but it seals the runnability component to the grooved roll. The air flow from the sealing means is from 5 to 100 m3 / h / m, preferably from 10 to 50 m3 / h / m. In turn, in order to create a vacuum 5 effect, the ejector effect should be in the order of 500-2000 m3 / h / m. The flow used in the sealing means is thus considerably smaller than the flow required to create vacuum under the ejector mechanism. Preferably, the sealing means is mechanical in that it does not need to operate the air flow, whereby the manufacture of the sealing means is simpler. In addition, the use of a non-airflow sealing means is more cost effective.

Fig. 2a shows a sealing member 32, which is a comb 50, used in connection with a groove roll in the system of the invention, seen from the front of the groove roll 12. The groove roll 12 and the sealing member 32 are not shown in full, but only in part. Between the tip 54 of the tooth 52 of the comb 50 and the bottom 58 of the groove 56 of the groove roll 12 there is a bottom slot 60. The height c of the bottom slot 60 is 0.5 to 2.5 mm, preferably 0.8 to 1.5 mm. There is a wall 60 'between the tooth 52 and the wall 62 of the groove 56 of the groove roll 12. The width d of the wall slot 60' is 0.5 to 2.5 mm, preferably ··· j. · t 0.8 - 1.5 mm The frame gap 60 '' between the frame member 64 of the comb 50 and the groove roll 12 has a frame gap 60 ''. The height e of the frame slot 60 '' is • ··. · * ·. 1.0 to 3.0 mm, preferably 1.3 to 2.0 mm.

• · M »··. Fig. 2b shows a sealing member 32 used in connection with the groove roll 12 in the system according to the invention, as seen from the ends of the groove rolls 12 · · 30. The sealing member 32 is a comb 50 with teeth * * 52 in more than one row 68. Preferably, the cam 52 has teeth 52 in two rows 68. Such a labyrinth seal of successive combs restricts the flow of runnable commands. · Efficiently at the component, for example, at very high speeds.

119560 9

Figure 3 shows a system 10 according to the invention, in which the groove roll 12 is a pivoting cylinder 34. In the pivoting cylinder 34, the energy saving of the runner roll 12 and the runnability component 18 containing the passive zone is enormous. Because, to create vacuum for the runnability components, the modern papermaking machines use a drying section of about 1 -2 MW on a machine over 10 m wide in connection with a prior art groove roll.

In the system 10 according to the invention shown in Fig. 3, the runnability component 18 is in the pocket space 37 of the single wire feeder. The passive zone of the runner component 18 is at least 500 Pa, preferably at least 800 Pa. Indeed, the system of the invention allows for simultaneous energy savings and higher vacuum in the pocket space of a single wire entry with a runnability component. This improves the runnability and control of the web properties.

In the system 10 according to the invention shown in Fig. 3, the first side 38 of the pivoting cylinder 34, from which the web 28 and 20 the wire 29 comes to the pivoting cylinder 34, has a closing gate 40.

; * · *; On the other side of the pivoting cylinder 42, from which the web 28 and • · · * · *; the wire 29 departing from the pivoting cylinder 34, is an opening opening 44.

• ·; ** ·. In addition, the runnability component 18 is adapted to be shaped such that the channel 46 extending into the opening piston 44 is pivotable. The entire runnability component, opening away from the 25 working cylinders 34, • over a distance of 18 sides.

In the system of the invention 10 shown in Fig. 3, the top of each side of the pivoting cylinder 34 has drying cylinders 36. The web 28 and the supporting wire 29 are arranged to * * be threaded into the single-wire threads of the drying cylinders 36 and 36. * ·· via slave cylinder 34. In addition, the web 28 is taken from the drying cylinders 36 to the turning cylinder 34 as a short export having a · · · * · .; length b is 80 to 600 mm, preferably 100 to 350 mm. When exporting * · 35 webs as a short export from a drying cylinder to a turning cylinder, the dryer section can be made more compact.

119560 10

Figures 4a-4c and 5 show systems 10 according to the invention, in which the web 28 touches the groove roll 12 1 to 120 °, preferably 4 to 30 °. The groove roll has an overflow portion having a hood in Figure 4a depicting a portion of the hood edge 41. There are only two rolls between the hood 5 edges in Figure 4a, but the hood edges could be substantially further apart. The system 10 includes a runnability component 18 between two groove rolls 12 which are on the same side of the wire 29. The currents directed to the runnability component 18 are generated by the operation of the two groove rolls 12 and the supported wire 29. Further, the runnability component 18 includes at least one passive zone in the transverse direction of the forming machine.

In the systems of the invention shown in Figures 4a-4c and 5, the runnability component 18 is in the pocket space 47 of the inflow section. The runnability component 18 has a vacuum of 50-500 Pa, preferably 100-300 Pa, in the passive zone. At this level of vacuum, the web control on the blowing section is functional. In addition, this pressure level is achieved by a very passive runnability component.

• «• · · • • t • ·

4a to 4c show runnability commands in connection with groove rollers 12. the components 18 are preferably passive. The edges of passive drive components can be mechanically sealed, eg • · ·

Im · 25 chic with a flat abrasion-resistant edge or • «. ···. la maze seal. Sealing can also be done with their • ψ combinations so that the frictional seal is best reached into the friction and the other edges are more freely sealed. With the runnability- * ·· * ... component being inactive, the space limited by the runnability component and the wire, i.e. the box, is preferably small.

* * The design will open towards the next groove roller, as shown in Figures ··· 4a and 4c. As the design is extended to the next groove roll, the reach of the roll suction effect area is improved, and the upstream wire • · **. Tj can partially underpress the runnability component by its • · 35 runner component and the opening opening formed by the wire.

119560 11

In Figs. 4a-4c, the sealing of the runnable component 18 which is passive and of the subsequent groove roll 40 of the next groove roll 12 also influences the negative pressure formed on the runner component 18. At its simplest, the seal is 5 directly against the groove roll, when the angle of attack between the seal and the groove roll does not form a closing friction, and otherwise, if desired, reduce the vacuum in the runner component. If a more efficient sealing is desired, or when the vacuum between the runner component and the groove roller is formed, the closing pressure can be enhanced by extending the sealing against the direction of rotation of the roller, the more the seal is restricted.

In the systems 10 of the invention shown in Figures 4a to 4c, the runnability components 18 between the groove rollers 12 are different. When sealing the opening rod 44 to the runner component 18, the most important thing is to prevent air from flowing from the groove roll and with the wire between the runner component and the wire. As a result, in the opening, the seal is extended as far as possible into the friction. However, at higher speeds and under reduced pressure * · · * · * · the bending of the wire towards the runnability component can be prevented and thus · · prevent the seal and the wire being worn by moving * »·: the seal slightly farther away.

In the systems of the invention shown in Figures 4a-4c, the control parameters associated with the runnability components 18 are; · # the length of the next sealing seal on the surfaces of the passive runner component 18 and the groove roll 12; followed by the opening of the runner · * 1 * 30 component and the opening cam of that groove roll.

* * The length of the sealant on the surface of the roll in its direction of rotation ··· is influenced by the amount of vacuum produced. Opening the Kidan; * ·, · in turn, affects the production of vacuum.

In the systems of the invention shown in Figures 4a-4c, at least one groove roll 12 is idle. The groove roller can be driven 12 119560 tons, since the groove roller can be implemented in a very lightly rotating structure. The lightly rotating groove roller does not need to be used, but receives the momentum required for rotation from the wire. Preferably, all of the groove rolls in the wire cycle are idle.

5

In the system according to the invention shown in Fig. 4a, the diameter d of the groove roll 12 is less than 1000 mm. As such, the diameter of the groove roll depends on the machine speed and width. The groove rollers are bearing at their ends. In the prior art, suction rollers are used to create vacuum in place of groove rollers of this size. The airflow required to create suction roller suction is passed through the suction roller bearing, whereby the bearings are sized according to the airflow. When the diameter of the groove roll is less than 1000 mm, the bearings at the ends of the groove roll have an inner diameter of less than 300 mm, preferably less than 150 mm. Using a groove roller instead of this size suction roller allows significant cost savings, as the bearings can be dimensioned for stress without having to pass suction flow through them.

Figure 5 illustrates the system of the invention in use with ϊ # ί [: vertical overhead blowing portion 70. Between track rollers 12; * ·]: Runner components 18 including at least one passive zone. The drive components containing the passive zone ··· · * · allow the vacuum level to be maintained ··· ♦ · * · “25 preferably with groove rollers, which is very advantageous. ***. with a vertical overhead section. The vertical overlay can effectively dry the web. Vacuum is needed to prevent overpressure in the closing • otherwise. they would not release the web from the support of the wire. This overpressure • · ··· • # 30 can also be prevented by deep groove groove rollers at least] * with partially passive runnability components. The production of a high vacuum level in accordance with the prior art requires! # *. J large suction means, since the benefit of a groove roll without: \ j at least in part a passive runner component is considerably less than a groove roll with a passive runner component. The 19560 runnability component enables efficient running of the groove roller with a vertical overhead blower with reduced energy consumption.

5 The structure of the pivoting cylinder 72 of the vertical blowing member used in the system of the invention shown in Figure 5 depends on machine speed. Slow machines can use a smooth roller. On the other hand, high speed machines use a groove roller and at least partly a passive drive component or suction roller as turning cylinders. When a smooth roller is used as a turning cylinder, the runnability components associated therewith must be active.

In the systems shown in Figures 1-5, a groove roll 12 is used, the grooves 56 of which have a depth f of 10 to 100 mm, preferably 20 to 50 mm. With the grooves in the groove roll being so deep, a vacuum is applied to the part of the groove roll covered by the web as the groove rotates. In turn, the groove width is 6-10 mm. The narrow heels between the grooves are 1 ~ 8 mm wide. Advantageously, the groove volume is remarkably large compared to conventionally grooved rollers and VAC rollers, which use an active runner component.

• * • · · # # # # ® ® ® ® ® ® ® ® ® ® m m * * * * m m m m • · ΦΦΦ • · ··· ♦ · Φ Φ Φ®Φ Φ φ • • • Φ φ φ Φ Φ Φ

Claims (12)

14 1 1 9560 A system for guiding a web (28) in connection with a groove roll (12) having a surface structure (16) having grooves (56) and the grooves (56) open only on the outer surface of the groove roll (12) and a groove roll The connection (12) comprises a runnability component (18), characterized in that the runnability component (18) comprises at least one passive zone (22) in the transverse direction (20) of the forming machine. 10 System according to Claim 1, characterized in that the runnability component (18) consists of a plurality of zones (24) in the transverse direction (20) of the forming machine, some of which are active zones (26) which are subjected to external vacuum. System according to claim 1 or 2, characterized in that a sealing member (32) is provided between the runnability component (18) and the groove roll (12). 20 System according to one of Claims 1 to 3, characterized in that the sealing member (32) is a comb (50). f · "" "" • · «* · • ·; m * T A system according to any one of claims 1 to 4, characterized in that the runnability component (18) is in a single-wire export pocket (37) and the runnability component (18) is passive. The vacuum zone (22) has a negative pressure of at least 500, preferably at least .. 800 Pa. System according to one of Claims 1 to 5, characterized in that the groove roll (12) is a pivoting cylinder (34). The system of claim 6, wherein the pivoting member 35 is provided on the pivoting cylinder (34), has a closure spigot (40), and on the other side (42) of the pivoting cylinder from which the web (28) departs. : the first side (38) of the working cylinder (34), from which the web (28) • · · 119560 of the pivoting cylinder (34), has an opening gap (44), characterized in that the runnability component (18) is adapted to be shaped ) extending from the pivoting cylinder (34) extending substantially from a distance along the entire 5 runnability components (18). A system according to claim 6 or 7, wherein drying cylinders (36) are provided on either side of the pivoting cylinder (34), up or down, through which the web (28) is arranged to be threaded in a single wire, characterized in that the web (28) ) to the swivel cylinder (34) as a short export having a length (b) of 80 to 600 mm, preferably 100 to 350 mm. System according to one of Claims 1 to 4, characterized in that the web (28) touches the groove roll (12) below 120 °, preferably below 30 °. System according to claim 9, characterized in that the groove roll (12) is on the blowing part. * ♦ • · 1 2 • · · • · A system according to claim 10, characterized in that the runnability component (18) is in an overflow section: a pocket space (47), and the runnability component (18) with a passive ··· · j1. In the 25 zones (22), the vacuum is between 50 and 500 Pa, preferably between 100 and 10 · 1 ·. 300 Pa. • · · «· System according to one of Claims 1 to 11, characterized in that the grooves (56) in the groove roll (12) have a depth 30 (f) of 10-100 mm, preferably 20-50 mm. • · • »• · ··· ♦ · • 1 · • · ·« ♦ · 1 2 • · ♦ 3 • · ie 1 1 9560