FI123352B - Controller for advancing a feeding tip in a fiber web machine and fiber web machine - Google Patents

Description

CONTROL DEVICE FOR TRANSPORTING THE MAIN TAPE IN A FIBER MACHINE AND A FIBER MACHINE

The present invention relates to a guide device for conveying a headband in a fiber web machine, the guide device comprising at least one baffle and an air channel and openings provided in the wall defining the air channel for transverse to the surface of the headband. The invention also relates to a fiber web machine.

The fiber web machine uses a variety of control devices based on the airfoil to convey and guide the headband. At its simplest, the control device is an air duct, the wall of which is provided with openings for forming air blows. There are also so-called blowing discs, whose operation is also based on air blowing.

20 With the blower tubes only, the threading strap is mainly controlled in a generic way. Instead, the baffle plate has a baffle plate, on which the air blowouts create a vacuum effect by means of a so-called coanda effect. In other words, the headband tends to follow the surface of the baffle with air blows along the direction of travel of the headband while moving the headband forward.

In a known blow plate, the openings open to a shoulder arranged between the air duct and the blow plate. Further, the air blows 30 are oriented substantially parallel to the blowing plate. In practice, air blows produce a vacuum effect, but at the same time significant friction is formed as the headband passes over the shoulder. A large part of the air blowing propulsion is lost. In addition, after the shoulder 35, the threading strap is released from the surface of the trackpad, thereby displacing sideways replacement air between the headboard and the trackpad. As the headband continues to advance, replacement air is increasingly absorbed 2. This will cause the tail strap to detach from the surface of the baffle and flutter the tongue, which may cause the tongue to break or the tongue to derail. This has resulted in the production of unnecessarily wide guide bars. The effective transport distance achieved by the known control device is short, which limits its use. In addition, the controls operate only in a relatively modest speed range. In practice, the speed of the fiber web machine must be less than 1500 meters per minute. Thus, known control devices 10 are poorly suited to current, let alone fibrous web machines. In addition to the speed limit, known control devices have another major problem. Large volumes of air have to be used, even to achieve satisfactory transport speed and power. This, in combination with the aforementioned replacement air 15, provides a significant amount of air moving around and with the headband. Practice has shown that at narrow intervals, the head failure fails mainly due to the blocking effect of a large amount of air. This has led to recourse to vacuum conveyor belts, which, however, have high acquisition and operating costs 20. In addition, vacuum belts conveyors are difficult to install in tight positions due to their large size.

It is an object of the invention to provide a novel device for conveying a threading strap in a fiber web machine which has a "simpler and lower structure" and which provides an increased export power with a smaller amount of air A and / or pressure. It is a further object of the invention to provide a novel fiber web machine, in which the transport of the thread is more smooth and reliable and the cc can be more versatile modified. Characteristic features of the device according to the invention and the fibrous web machine are that the baffle o is of sheet material and has a substantially straight plane without any frictional shoulders or other protrusions, and the angle β between the blowing direction 35 and the baffle is 5-30 °, more preferably 10 - 20 °. The opening of the openings in the baffle plate 3 instead of the shoulder avoids the friction effect that previously caused the problems. At the same time, the replacement air between the headband and the guide plate is avoided. In addition, in the absence of a linear friction point, air blasting advances web-like material 5 more rapidly than before. At this point, the current airflow achieves a greater forward force. On the other hand, the current force can be achieved with a smaller amount of air or a lower pressure level than before. When the baffle plate is part of the air duct, the manufacturing of the control device is facilitated. 10 At the same time, the structure of the control unit is light and shallow but rigid.

The invention will now be described in detail with reference to the accompanying drawings, in which:

Figure 1 is a side elevational view of a portion of the position of a fiber web machine employing a plurality of control devices according to the invention for conveying the thread 20.

Fig. 2a is a front view of a first embodiment of a control device according to the invention,

Fig. 2b is a bottom sectional view of Fig. 2a, Fig. 3a is a partial sectional view of Fig. 2a, o Fig. 3b is a partially enlarged view of Fig. 3a, ^ Fig. 4 is a side elevational view of a second position of a fibrous web machine. threading

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Fig. 5 shows a second embodiment of a control device according to the invention.

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Fig. 6 shows a third embodiment of a control device according to the invention.

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Figure 1 is a side view of a bonding press 10 for a fiber web machine. The forming machines are, for example, paper and board machines. The surface sizing is based on the film transfer technique. A starch-containing solution is applied to the rolls 11 and 12 to form a thin film which is transferred to the fibrous web in the roll nip. For surface sizing, the fibrous web is introduced from the preceding drying section, and after the surface sizing, the fibrous web is directed here through air dryers 13 and 14 to the additional drying section. In the exemplary embodiment, at the end of the drying section, at the end of the drying section, the fibrous web is driven down to the wreckage. From the fibrous web, a threading strap 15 is cut, which is started to be advanced, for example, by a vacuum belt conveyor. The threading strap 15 of Figure 1 is in some way provided to a guide roll 16, from which the strapping strap 15 is conveyed quickly and securely through an apparatus formed by a plurality of control devices 15 according to the invention through an adhesive press 10 and air dryers 13 and 14. In Figure 1, the roll nip has been opened by moving the upper roll 12 and the air dryer nipples 13 and 14 have been moved to the open position to allow head roll. The control device according to the invention may also be disposed in the threads of, for example, coating stations and calenders, which may be long and include narrow gaps. The control device can thus also be used on other parts of the fiber web machine. During production, at least part of the controls is moved to the rest position.

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The fibrous web machine thus comprises one or more control means 17 for conveying the threading strap. One control device 17 according to the invention is shown in Figures 2a and 2b. The control device 17 includes at least one baffle plate 18 and an air channel 19 as well as openings 21 provided in the wall 20 limiting the air channel 30 to form airflow obstructions downstream of the baffle surface 22 of the baffle plate 18. Air blows both keep the headband in check and move it forward. In other words, the air blows together with the surface of the baffle produce a vacuum effect, whereby the threading strap tends to follow the baffle. At the same time, air blows push the headband forward. According to the invention, the baffle plate 18 is arranged as a structural part of the air channel 19 and the openings 21 are formed in the base material of the baffle plate 18. In this case, the construction of the control-5 device is particularly simple and shallow. In addition, the oblique openings open to the planar surface, thereby preventing replacement air from entering between the headband and the baffle plate. In this case, the amount of air carried with the headband is a fraction of what is known, whereby the headline is also achieved through narrow gaps 10. In addition, due to the shallowness, the control device 17 fits, for example, in Figure 1 between the rollers 11 and 12 and the subsequent air dryers 13 and 14.

The shoulderlessness and the openings in the plane surface prevent the formation of friction 15 and provide an effective forward force. The smooth operation of the baffle 18 is also facilitated by reliable operation and a long effective export distance. In other words, the trackpad is flat and straight from start to finish. However, the baffle extension may be a guide to deflect the head-20 tin strip. In this case, the purpose is to remove the head-export tape while changing its direction. The planar trackpad is also simple to fabricate. In particular, there is a substantially even 150 mm section across the vent openings forward of the replacement air vents without any angles or obvious protrusions. The flap 25 has a flatness of ± 2 mm and small deviations are possible over the entire distance.

In the embodiments shown, a portion of the air channel 19 is formed by an open profile 23 which is hermetically secured to openings 30 21 on the surface 22 of the headband side opposite to the surface 24 of the missile plate 18. Figure 2b is a U profile and Figure 5 is a V profile. Both are preferably standard profiles, which further simplifies the manufacture. If the control device is made of metal, the profiles are preferably welded 35 to the underside of the guide plate. In this case, the profiles additionally stiffen the baffle, whereby separate Frame structures are unnecessary. On the other hand, for example, plastic profiles can be fixed by gluing, which may require the use of separate support structures.

In the embodiment of Figures 2a-3b, two functional baffles are formed from a single piece of plate. Here the sheet material has a thickness of 3 mm and the sheet material is made of acid-proof steel. The control device can be manufactured, for example, in the following manner. For example, laser cutting cuts a suitable piece of sheet material 10 and bends the edges of the baffle into stiffeners. Next, with a pin cutter, for example, a notch 25 is machined on the opposite surface 24 of the threading strip side 22 on the opposite surface of the missile plate 18, into which the opening 21 is formed, for example, by the same pin cutter. The slot allows the opening, here a hole 15, to be machined perpendicular to the material, which greatly facilitates machining, especially at the start. However, the openings are oblique to the plane of the trackpad. Figure 3b shows in more detail a notch 25 which may extend from one edge of the baffle 18 to one edge or be machined only at the apertures. Thereafter, the inlet edges of the baffles are shaped. The slot and openings can also be machined before bending the edges of the trackpad. It is also possible to use composite materials, plastics, wood, metal or combinations thereof. The material may have a thickness of 2 to 10 mm in one or more layers. For example, two dampers are superimposed, whereby the groove in the lower dampers replaces the milled groove for drilling.

According to the invention, in the direction of travel of the threading band, the inlet edge 26 of the guide plate 18 30 has a rounding 27 which pivots away from the surface 22 of the threading side. In this case, the threading strap will surely be directed to the trackpad. At the same time, a gap 28 is formed between the two consecutive baffles, in which the air of the previous blast can escape without passing through the slot 35. The rounding also directs a bit of replacement air to the subsequent air blast so that the headband is not absorbed by the baffle 7 to rub it. In the embodiment of Fig. 3b, the radius of rounding is 15 mm and the rounding rotates 60 ° downwards. Thus, the control device may comprise a plurality of consecutive baffles, each with its own air channel with openings. In figure 5, four guide plates 18 are included in one guide device 17, which are fastened to the profiles and to each other in a self-supporting structure here preferably by means of a longitudinal air connection.

The profiles equalize the amount of air in the openings. In addition, the profiles are connected by a pipe or other closed profile. By arranging the openings in the transverse profile and the longitudinal profile at the same points, a functional manifold is provided which at the same time acts as a longitudinal stiffener. In the manufacture, the transverse profiles are hermetically sealed to 15 longitudinal profiles, whereupon the transverse profiles are welded to the baffle to complete the control device. In Figure 3b, tube 29 has a hole 30 slightly larger than the hole 31 in the U-profile. The airtight weld 32 is at the junction of these holes. Another airtight weld 33 is between the U-profile and the guide plate 18. In this case, the compressed air supplied to the tube 29 is distributed in the U-profile and thereafter through the openings 21 to the surface 22 of the baffle side of the baffle 18 for air blowing. The guide device can be carried directly from the longitudinal profile, for example, by means of the bracket 34 shown in Fig. 5, which 25 can be fastened at different points in the longitudinal profile. There may also be more than one bracket. Compressed air is supplied to the manifold, for example, by a hose, whereby the control device can be moved and / or turned from a rest position to a head-up position and vice versa. 2a, the height of the control device 17 is less than 50 mm, taking into account the manifold 30.

Fig. 6 shows a third embodiment of the control device, with hinge means 35 between the baffles 18 for changing the mutual angle of the baffles 18. Of this, the four middle 35 baffles are rigidly supported to form a level. On the inlet side there is one baffle 18 pivotally supported by hinge means 35.

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Correspondingly, there are two pivotable support baffles 18 on the discharge side. The hinge means provide sufficient rigidity while at the same time keeping the structure of the control device simple. The hinge means are lockable so that the desired position is maintained during use.

Advantageously, the hinge means are further disassembled, whereby one type of individual control device can be manufactured and then, by combining the required number of control devices, a longer and formable device is obtained if necessary. Figure 6 shows longitudinal manifolds which are connected by a flexible hose 10a to distribute compressed air to air ducts (not shown). The flexible hoses allow the angle of the baffles with hinge means to be changed.

The fiber web machine may include one or more control means 15 for conveying the threading strap in the fiber web machine. Preferably, a plurality of guiding means 17 are successively formed to form a versatile and reliable apparatus for conveying the strap. Preferably, the control means are spaced apart, whereupon the air blast, which has lost its kinetic energy, may exit before the next control device. In practice, there is a gap of 10 to 50 mm, more preferably 15 to 30 mm, between the guiding devices. In addition, the control device is arranged within a limited spacing 36, such as between rollers 11 and 12 of Figure 1. Despite the narrow gap, the threading strap passes through the surface of the baffle 25. The known blower-based controls are completely inoperative in such positions. In fact, Figure 1 shows four assemblies having a total of twenty-two controls. The control device can even operate upside down and the headband can be reliably moved from one system to another. In Figure 1, the threading strap 15 is changed three times from one apparatus to another. In this case, the control devices can be combined in many ways without compromising the reliability of operation. Figure 4 shows another arrangement in which the direction of travel of the headband is reversed. Thanks to the safe operation 35 of the control device according to the invention, the threading strap is kept under control without fluttering, whereby the route shown is possible and has been practically tested.

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In addition, the new function enables the control devices to be angled relative to each other. According to the invention, the inlet angle α between the threading strip from the preceding roll and the guide device 17 is 0 to 15 °. The threading strap can then enter the control device even at an angle and still remain under the control of air blows. In Figure 4, the angle of incidence α is about 13 °. The angle between successive baffles may be substantially greater than the aforementioned angle.

In the embodiment shown, the apertures 21 are formed in the base material of the baffle 18 and the angle β between the blowing direction of the apertures 21 and the baffle is 5 to 30 °, more preferably 10 to 20 °. In Fig. 3b, the angle β is 15 °. Thus, according to the invention, the apertures open on the baffle-facing side surface 22 of the baffle, thereby avoiding harmful shoulders. In other words, the trackpad is flat without any friction-causing shoulders or other protrusions. Secondly, blows at a suitable angle, on the one hand, provide a sufficient vacuum effect and, on the other hand, effectively advance the web-like material.

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Preferably, the apertures 21 have a distance from the leading edge of the baffle of 10 to 50 mm, more preferably 10 to 25 mm. This dimension refers to the straight portion of the trackpad, excluding rounding. Thereby, when the strap arrives at the control device, there is a supporting surface 25 thereof before the export effect of the air blows. At the same time, a vacuum effect begins to form at the very beginning of the device, which in turn minimizes frictional forces and reduces the size of the control device.

The new design and the positioning of the openings make it possible to manufacture control devices of very short and long lengths. According to the invention, the baffle 18 has a dimension of 100 to 500 mm, more preferably 200 to 400 mm, in the direction of the web material. This dimension refers to the effective dimension that can be achieved in a single duct. By installing a plurality of 35 successive air channels with baffles, the effective dimension of the baffle 10 can be increased. Another option is to fit several control devices in series or to combine the two ways.

Preferably, the openings 21 are formed of holes 37. In other words, air blows 5 are formed without separate nozzles. The holes are easy to work with, for example, a spindle cutter, especially when using a notch. Plastic and plastic composite materials are also possible. According to the invention, relatively small holes with a diameter of 1 to 3 mm, more preferably 1.5 to 2.5 mm, are used. In this way, the air consumption remains reasonable. In Figure 3b, the hole 37 has a diameter of 1.6 mm. In addition, separate nozzles are unnecessary. Depending on the basis weight of the transportable strap and the distance traveled, the hole spacing is selected on a case-by-case basis. In general, the distance between the holes is 10 to 50 mm, more preferably 10 to 25 mm, so that the larger the holes, the further apart. Instead of a straight row, the holes can be arranged, for example, overlapping or obliquely, to direct the vacuum effect as desired. In Figure 2b, the central area is 200 mm in size and the holes are 10 mm apart. The edge areas 20 are 50 mm wide and the holes are 25 mm apart. This produces a centering effect on the headband.

According to one embodiment, the central openings in the trackpad may be larger than the openings in the peripheral regions (not shown). Thereby an enhanced blowing effect is obtained on the center portion of the baffle which automatically centers the transportable headband. In other words, a centering force is formed which holds the headband longitudinally substantially in the middle of the baffle. At the same time, the detrimental effects of the openings outside the headband are reduced as the venturi decreases. For example, the area of more efficient blowing may be from one third to two thirds of the blowing width of the device, preferably about half the blowing width, but still less than the width of the headband. A control device 17 with an enhanced blow zone is shown in Fig. 2a, where the duct tape 15 is shown by a dotted line. The enhanced blowing area 11 may also be formed with slits, with holes in the peripheral areas or vice versa.

The apertures may also consist of slits that can be machined by 5 lasers. The slots provide very smooth air blowing and, in addition, the sound of the air discharged from the slits is smaller compared to the holes. The gap may have a width of 0.05 to 1 mm, more preferably 0.1 to 0.5 mm. Slots can also be placed directly in a row or suitably overlapped to provide a comprehensive and smooth air blast. The length of the slit depends mainly on the requirements of the case and the width of the slit. The discontinuous gaps are longer than 5 mm, preferably longer than 10 mm. The gap may also be uniform, almost the entire width of the control device. In this case, the gap width is about 200-300 mm, up to 400 mm for particularly wide applications.

Because of its simple construction and low friction, very different pressures can be applied to the control device. According to the invention, the control device and in particular the openings are dimensioned so that a pressure of 0.25 to 7, more preferably 0.5 to 2 bar can be applied. This allows significant forces to be applied to the headband even at low pressure. On the other hand, even high pressures can be used, which can be utilized in particular to provide a sufficient flow rate. In other words, 25 devices can be used in high speed fiber web machines.

The dimensioning of the control device according to the invention may vary in different applications. However, it is essential to have openings on the flap-to-rib side of the trackpad to avoid previous friction problems. Also significant are the air blows at a certain angle, which can both safely capture and transport the web material forward. Further, fitting the baffle plate into the air channel simplifies the structure of the baffle. The structure is lightweight 35, rigid and extremely low. In addition, inexpensive materials and processing methods may be used. The work steps 12 are few and fast. Only machining small holes can be challenging, but that too has been solved with the notch described above. Compressed air is evenly distributed in the air ducts and the control unit is easy to carry. The new design 5 prevents replacement air from entering between the headband and the baffle, ensuring that the headband is securely controlled. At the same time, the headband can surely be moved from one device to another, allowing the formation of long and complex pathway equipment. In addition to all other good 10, the control device according to the invention operates even in fast fiber web machines with a production speed of more than 2000 meters per minute.

Claims (10)

13 A guide device for conveying a headband in a fiber web machine, the guide device (17) comprising at least one guide-plate (18) and an air channel (19) and openings (21) in the wall (20) bounding the air channel (19). and a baffle plate (18) for forming air blows to the surface (22) of the tapping tape side and thus for conveying the tapping tape (15), and the baffle plate (18) being arranged as a structural part of the air channel (19) , and the baffle plate (18) includes a straight portion arranged as a support surface before the air blows, characterized in that the baffle plate (18) is of sheet material and is a substantially straight flat plane without any frictional shoulders or other protrusions; 18) the angle β between 5 and 30 °, more preferably between 10 and 20 °. Control device according to Claim 1, characterized in that a part of the air channel (19) consists of an open profile (23) hermetically secured to the openings (21) on the surface (24) of the missile plate (18) opposite to the surface (22). . 25 Control device according to Claim 1 or 2, characterized in that a notch (25) is provided on the surface (24) of the missile plate (18) opposite the side surface (22) of the threading strip (15), in which the opening (21) is formed. 30x Control device according to one of Claims 1 to 3, characterized in that in the direction of travel of the threading strap (15), the inlet edge (26) of the guide plate (18) has a rounding (27) which is inclined 35. pivots away from the surface (22) facing the threading strip (15) 14 Control device according to one of Claims 1 to 4, characterized in that the control device comprises a plurality of successive baffles (18), each of which has its own air channel (19) with openings (21). 5 Control device according to Claim 5, characterized in that between the guide plates (18) there are hinge means (35) for changing the mutual angle of the guide plates (18). A fiber web machine comprising one or more guide means (17) for conveying a threading strap in a fiber web machine comprising at least one guide plate (18) and an air channel (19) and openings (21) provided on the wall (20) delimiting the air channel (19). to form air blows in the direction of travel 15 and directed to the tongue-side surface (22) of the baffle (18) and thereby to convey the tongue, and the baffle (18) is arranged as a structural part of the air channel (19) and bores (21) 20, and the baffle plate (18) includes a straight portion arranged as a support surface prior to air blowing, characterized in that the baffle plate (18) is of sheet material and is a substantially straight plane without any frictional shoulders or other protrusions; ), the angle β between the blowing direction and the baffle (18) is 5 to 30 °, ed more generally 10-20 °. c \ j A fiber web machine according to claim 7, characterized in that the control device (17) is a control device according to any one of claims 2 to 6. ° 30 X A fiber web machine, σ) according to claim 7 or 8, characterized in that a plurality of control means (17) are arranged in succession and cd .... g are arranged within a limited spacing (36). A fiber web machine according to claim 9, characterized in that the inlet angle α between the threading strap (15) from the preceding roll (16) and the guide device (17) is between 0 and 15 °. o CM 15