EP1960593B1 - Blade for flexibly supporting a wire and twin-wire section - Google Patents

Abstract

This invention relates to a rail for the compliant supporting of a mesh in the region of a double mesh zone of a double mesh section of a machine for producing a fibrous web, including a movable head rail, a movable bearer rail, a fixed guide rail, a compliant pressing apparatus, and a compliant return apparatus for moving the movable bearer rail together with the movable head rail from the operating position to the resting position and for holding the two rails in the resting position. The compliant return apparatus has, spread over the length of the movable bearer rail, several movable return hoops which at the one end can be made to engage at least temporarily with the movable bearer rail and at the other end can be loaded at least temporarily by at least one return element respectively arranged between the fixed guide rail and the movable return hoop.

Description

The invention relates to a bar for resilient support of a sieve in the region of a twin-wire zone of a twin-wire section of a machine for producing a fibrous web, in particular a paper or board web, comprising a movable head strip which extends transversely to the direction of the sieve and on at least partially the sieve slides during operation of the machine, a movable support bar which is rigidly connected to the movable header and which also extends transversely to the direction of the wire and is guided in a fixed structure, a fixed guide bar which is rigidly arranged in the fixed structure and which in turn extends transversely to the direction of travel of the screen, a resilient pressing device which is arranged between the movable support bar and the fixed guide rail to the movable support bar together with the movable header between a rest position and a bet rubbing position, in which the movable head strip is pressable with a selectable force on the screen, and a resilient return means for bringing the movable support bar together with the movable head strip from the operating position to the rest position and the attitude of the two strips in the rest position.

Furthermore, the invention relates to a twin-wire section of a machine for producing a fibrous web, in particular a paper or board web.

Such a bar is for example from the German patent application DE 40 19 884 A1 known. As a resilient return device for retrieving the movable support bar in the rest position is a return power source, preferably a spring provided.

This is disadvantageous in that at least the return force has to be overcome when bringing the movable support bar from the rest position into the operating position. Also, during the attitude of the movable support bar in its operating position, a force must be at least expended at least greater than the return force, so that the movable support bar remains reliable in the desired operating position. This actuating mechanism thus requires at least during operation of the machine a force that is significantly greater than the force required for the attitude of the movable support bar in the operating position.

It is therefore an object of the invention to improve a strip of the type mentioned in such a way that their positions, in particular the operating and the rest position can be made with much less force and kept safe to operate. In particular, the return mechanism of the bar should be largely without any influence on their postural forces in their operating position. Furthermore, a corresponding twin-wire section should be specified.

This object is achieved in that the resilient return device distributed over the length of the movable support rail away has a plurality of movable return bracket, which are at least temporarily engageable at one end with the movable support bar in engagement and at the other end of at least one each between the fixed Guide bar and the movable return bracket arranged return element are at least temporarily acted upon.

The object of the invention is completely solved in this way.

Due to its design in the form of a plurality of movable return straps with at least temporary engagement, this return device according to the invention ensures that they do not continually engage the strip and thus do not continually represent forces to be overcome. For bringing the strip from its rest position into an operating position or from an operating position to a changed operating position, therefore, no return force applied by the return device according to the known state of the art must be overcome. In addition, the return mechanism according to the invention is largely insensitive to contamination of any kind. The complete strip system is characterized by a compact design, so that it can be arranged, for example, in the initial dewatering section of the twin-wire section, in particular directly after a forming element, preferably a forming roller.

In a first embodiment, the movable support strip on at least one, preferably a plurality of recesses, in which one ends of the movable return bracket are at least temporarily engageable. In the case of a depression, it would extend along the movable support bar. Preferably, however, the number of wells is equal to the number of one ends, so that at least temporarily, a corresponding end can intervene in each well. The recess is in this case preferably a rectangular recess.

The respective return element is preferably formed from a practical point of view as an at least temporarily acted upon by a pressure return hose. He preferably extends at least between the two edge-side return bars along the fixed guide bar. In the application, he will most likely extend over the full or approximately complete length of the fixed guide rail, so that he is at least driving or leader side easily accessible. Of course, for each return bar a single Be provided return element, but this can lead to cost and complexity disadvantages.

Furthermore, the preferred only return hose is guided at least partially in terms of its circumference, in particular at least on the underside, in a recess attached to the upper side of the fixed guide rail. This type of leadership ensures that he is on the one hand safe to run and that he is on the other hand protected during his resting phase and stored clean.

At the one end of the respective return bar, a centering element, in particular a centering pin, is preferably arranged on the inside. This centering is acted upon at least temporarily, that is, during operation of the retractor of a longitudinal rib attached to the return hose. This embodiment ensures a favorable and reproducible Beschlagung the return bar through the return hose.

Thus, the reliability of the return strap is continuously ensured, it is preferably by means of several in the fixed structure mounted guide elements, in particular guide pin, both sides and limited. Thus, the cleverly arranged guide elements limit the maximum displacement of the return bar and determine, inter alia, his rest position, in which he comes due to its weight.

Furthermore, in a preferred embodiment, the fixed structure comprises a plurality of preferably triangular partition plates, which are arranged both at a distance from each other on a supporting body extending transversely to the running direction of the screen and in the region of the return bars and which at least partially surround the fixed guide strip and the movable support strip in a clip-like manner , Such bulkheads provide due to their design and arrangement maximum stabilities for the bar system at relatively low weights.

The support body has on the side facing away from the bulkhead plates preferably a plurality of T-slot guides for its attachment to a further component. Among other things, this type of attachment has the practical advantage that the complete strip system can be disassembled separately without machine downtime. So it can be replaced, for example, if necessary, by a known bar system with fixed bar arrangement. The same applies, of course, in the opposite case.

Thus, the tightness of the setting space for bar adjustment is ensured without friction losses on the strip body, the bulkhead plates are preferably provided on its side facing the screen with a transverse to the direction of the screen extending rear wall. The rear wall is mounted in a favorable design by means of at least one guide rail on the partition plates, so that they can be easily removed from the machine if necessary.

In addition, the partition plates on their side facing away from the screen can preferably also be provided with a front wall extending transversely to the running direction of the screen. This front wall gives the strip system in turn an additional degree of stability while ensuring the above tightness. In a favorable embodiment, moreover, at least in sections, in particular between the bulkhead plates, sealing elements extending transversely to the running direction of the sieve are arranged between the front wall and the movable carrier strip. The sealing elements are designed under practical aspects as a rule as a tailor-made sealing strips.

For the interior care of the space formed from the support body, the rear wall and the front wall is preferably arranged in the upper region of the partition plates extending transversely to the running direction of the screen cleaning device, in particular a spray tube. Such Cleaning device is already known from other applications in the field of a machine for producing a fibrous web, so that their construction and operation will not be discussed here.

Furthermore, in a preferred embodiment, at least one return bar is provided with a preferably central longitudinal recess in which the associated partition plate is guided. In this case, moreover, the guide elements, in particular guide pins, are mounted on the partition plate for guiding the return bar. This embodiment provides the advantage of a power and torque-reduced design for a given reliability.

A practical embodiment of a twin-wire section of a machine for producing a fibrous web, in particular a paper or board web, is characterized in particular by a skimmer strip and / or at least one dewatering strip which corresponds in construction and function to the strip according to the invention. Under process-technological aspects, the twin-wire section can, of course, also have a plurality of drainage strips arranged in the running direction of the wire.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings.

Show it

FIG. 1

a schematic side view of the strip according to the invention in its operating position;

FIG. 2

a schematic side view of the strip according to the invention FIG. 1 in their resting position;

FIG. 3

a schematic detail of the lower part of the strip according to the invention FIG. 1 ;

FIG. 4

a further schematic detail of the upper part of the strip according to the invention FIG. 1 ; and

FIG. 5

a schematic perspective view of the return bar of the bar according to the invention FIG. 1 ,

The FIG. 1 shows a schematic side view of the strip 1 for resilient support of a screen 2 shown in dashed lines in the region of a twin-wire zone of a twin-wire section of a machine for producing a fibrous web, in particular a paper or board web, in its operating position. In the operating position, the strip 1 is pressed into the wire 2 in a range of 0.5 to 5 mm, preferably 1 to 3 mm. The strip 1 can be oriented at an angle α of +/- 90 ° to the vertical V depending on the course of the screen 2.

The Quiet 1 consists of a movable head strip 3, which extends transversely to the direction L (arrow) of the wire 2 and slides over the at least partially the wire 2 during operation of the machine. The head strip 3 is in view of a minimization of wear on the wire 2 of a ceramic material.

Furthermore, the bar 1 consists of a movable support bar 4 which is rigidly connected to the movable header 3 and which also extends transversely to the direction L (arrow) of the screen 2 and also guided in a fixed structure 5. Furthermore, the strip 1 comprises a fixed guide strip 6, which is arranged rigidly in the fixed structure 5 and in turn extends transversely to the running direction L (arrow) of the wire 2. The rigid arrangement of the guide bar 6 in the fixed structure 5 can be done for example by means of mutually arranged groove connections 7.1, 7.2, so that the guide bar 6 transversely to the direction L (arrow) of the screen 2 is removable from the machine.

Between the movable support bar 4 and the fixed guide bar 6 a resilient pressing device 8 is arranged. This serves to move the movable support bar 4 together with the movable header 3 between a rest position ( FIG. 2 ) and the illustrated operating position in which the movable head strip 3 is pressed against the wire 2 with a selectable force F (arrow). The pressing device 8 is formed for example as a Anpressschlauch 9, which is acted upon during the operating phase by an unillustrated, known to the expert pressure source, for example in an embodiment of a preferably controllable / controllable pressure pump, with an operating pressure pA (arrow). The pressure hose 9 preferably extends along the fixed guide rail 6 and is at least partially in terms of its circumference 9U, in particular at least on the upper side, in a on the fixed guide bar 6 underside mounted recess 10, in particular a groove 10.1, out. The fixed guide rail 6 thus also serves as a carrier system for the pressing device 8, in particular for the pressure hose 9.

Furthermore, the strip 1 comprises a resilient return device 11 for bringing the movable support strip 4 together with the movable head strip 3 from the illustrated operating position into the rest position (FIG. FIG. 2 ) and the attitude of the two strips 3, 4 in the rest position ( FIG. 2 ).

The flexible return device 11 has distributed over the length of the movable support bar 4 away a plurality of movable return bracket 12, which are at least temporarily engageable at one end 12.1 with the movable support bar 4 and at the other end of at least one of each 12.2 between the fixed guide rail 6 and the movable return bar 12 arranged return member 13 are at least temporarily acted upon. The temporary "engagement-engagement" and the temporary "application" takes place during the bringing of the two strips 3, 4 from the illustrated operating position into the rest position (FIG. FIG. 2 ) and during the Rest position ( FIG. 2 ).

The movable support bar 4 also has a plurality of depressions 14 (FIG. FIG. 3 ), in which the one ends 12.1 of the movable return bar 12 are at least temporarily engageable. The single recess 14 is preferably a rectangular recess.

Furthermore, the respective return element 13 is designed as a return hose 15 that can be acted upon at least temporarily by a pressure p R (arrow). The pressure pR (arrow) is again generated by a pressure source (not shown) known to a person skilled in the art, for example in a design of a preferably controllable pressure pump.

The return hose 15 extends at least between the two edge-side return straps 12 along the fixed guide rail 6. It is at least partially in terms of its circumference 15U, in particular at least on the underside, in a fixed to the fixed guide bar 6 top recess 16, in particular a groove 16.1 out , The fixed guide rail 6 thus also serves for the return hose 15 as a carrier system.

At one end 12.2 of the respective return bar 12, a centering element 17, in particular a centering pin 17.1, is mounted on the inside. The centering bolt 17.1 is at least temporarily acted upon by a longitudinal rib 18 attached to the top of the return hose 15.

Furthermore, the return bar 12 by means of several mounted in the fixed structure 5 guide elements 19 is guided on both sides and limited. The guide elements 19 are preferably designed as guide pins 19.1.

The fixed structure 5 comprises a plurality of, preferably triangular partition plates 20, which are arranged both spaced from each other on a transverse to the direction L (arrow) of the screen 2 ersteckenden support body 21 and in the region of the return bar 12 and at least the fixed guide rail 6 and movable support bar 4 at least partially surround like a clip.

Further, the support body 21 on the side facing away from the bulkhead plates 20 side a plurality of T-slot guides 22 for its attachment to a further component 23. The further component 23 may, for example, be a non-explicitly illustrated upper sieve suction box of the twin-wire section.

The bulkhead plates 20 are provided on their side facing the wire 2 with a transverse to the direction L (arrow) of the wire 2 extending rear wall 24 which is attached by means of at least one guide bar 25 to the bulkhead plates 20. Furthermore, they are also provided on their side facing away from the wire 2 with a front wall 26 extending transversely to the running direction L (arrow) of the wire 2. The two walls 24, 26 may of course be designed in several parts for the purpose of improved handling.

In the upper region of the bulkhead plates 20 there is arranged a cleaning device 27, extending transversely to the running direction L (arrow) of the screen 2, for interior care of the space 28 formed by the carrier body 21, the rear wall 24 and the front wall 26. The cleaning device 27 is, in particular, a spray tube 27.1 known to the person skilled in the art whose effective direction is directed to the important components and assemblies arranged in the space 28.

In addition, in the upper region of the bulkhead plates 20, a laterally arranged injection 32 is provided in a possible embodiment of an air tube, by means of which at least one fluid, in particular air, is injected continuously, periodically or as needed for generating an overpressure in the interior can. The injection thus serves above all to avoid mist which penetrates into the interior and to further minimize soiling in the interior. The injected fluid (arrow representation) can escape in a targeted manner via a between the support bar 4 and the rear wall 24 transversely to the running direction L (arrow) of the screen 2 extending air outlet gap 33.

The FIG. 2 now shows a schematic side view of the in the FIG. 1 bar 1 shown for yielding support of the screen 2 shown in dashed lines in the region of a Doppelsiebzone a Doppelsiebpartie a machine for producing a fibrous web, in particular a paper or board web, in its rest position. In this position, the strip 1 is lifted off the screen 2 by means of the resilient return device 11.

The resilient return device 11 has, as already in the description of the FIG. 1 executed, over the length of the movable and transversely to the direction of L (arrow) of the wire 2 extending support bar 4 away distributed on several movable return bracket 12, which are at least temporarily engageable at one end with the movable support bar 4 at 12.1 and the other End 12.2 of at least one each between the fixed guide rail 6 and the movable return bar 12 arranged return element 13 are at least temporarily acted upon.

During the illustrated rest position of the respective return bar 12 is moved by the acted upon by a pressure pR (arrow) return hose 15 in an upper position. The pressure pR (arrow) is generated by a pressure source (not shown) known to a person skilled in the art, for example in the design of a preferably controllable pressure pump.

The FIG. 3 shows a schematic detail of the lower part of the in the FIG. 1 shown bar 1.

The movable support bar 4, which is rigidly connected to the movable head strip 3 and which also extends transversely to the running direction L (arrow) of the screen 2 shown in dashed lines, is guided in the fixed structure 5 so as to be stable against tilting. For this, the fixed structure 5 designed as bulkhead plates 20 has a plurality of guide surfaces 29.

Between the front wall 26 and the movable support bar 4 at least in sections extending transversely to the running direction L (arrow) of the screen 2 shown by dashed lines extending sealing elements 30, in particular sealing strips 30.1 arranged. Taking into account constructional aspects, the sealing strips 30.1 attached to the front wall 26 by means of a plurality of screws 31 extend at least between the partition plates 20.

Furthermore, it can be seen that the return bar 12 with its end 12.1 at least temporarily engageable with the mounted in the movable support bar 4 recess 14 in vorzugsweiser form of a rectangular recess in engagement. The return bar 12 is guided by means of several mounted in the partition plate 20 guide elements 19 on both sides and limited. The guide elements 19 are preferably designed as guide pins 19.1.

And the FIG. 4 shows a schematic detail of the upper part of the in the FIG. 1 shown bar 1.

The fixed guide rail 6 has on the upper side a recess 16, in which at least partially with respect to its circumference 15U, in particular at least on the underside, the return hose 15 of the return device 11 is guided. The fixed guide rail 6 thus serves as a carrier system for the return hose 15th

The return hose 15 is at least temporarily acted upon by a pressure pR (arrow) ( FIG. 2 ), by a non-illustrated, the expert However, known pressure source, for example in an embodiment of a preferably controllable / controllable pressure pump is generated.

The return hose 15 extends at least between the two edge-side return straps 12 along the fixed guide rail 16. At one end 12.2 of the respective return bar 12, the centering element 17, in particular the centering pin 17.1, is mounted on the inside. The centering bolt 17.1 is at least temporarily acted upon by the longitudinal rib 18 attached to the top of the return hose 15 ( FIG. 2 ).

Furthermore, the return bar 12 is guided by means of several mounted in the partition plate 20 guide elements 19 on both sides and limited. The guide elements 19 are preferably designed as guide pins 19.1.

The FIG. 5 Finally, shows a schematic perspective view of the return bar 12 of the bar 1 of FIG. 1 ,

It can be seen that the return bar 12 is provided with a preferably central longitudinal recess 31, in which the associated, but merely indicated partition plate 20 is guided.

The in the FIGS. 1 to 5 shown strip 1 is particularly suitable for use as a skimmer or dewatering strip in a twin-wire section of a machine for producing a fibrous web, in particular a paper or board web. Of course, the twin-wire section may have a plurality of such drainage strips.

In summary, it should be noted that a strip of the type mentioned is created by the invention, their positions, in particular the operating and the rest position, can be made with significantly less force and kept safe to operate. In particular, the Return mechanism of the bar largely without any effect on their postural forces in their operating position.

LIST OF REFERENCE NUMBERS

1

strip

2

scree

3

header

4

supporting strip

5

structure

6

guide rail

7.1,7.2

groove connection

8th

pressing device

9

pressure tube

9U

scope

10

deepening

10.1

groove

11

retractor

12

Rückholbügel

12.1

The End

12.2

The End

13

return element

14

deepening

15

return hose

15U

scope

16

deepening

16.1

groove

17

centering

17.1

centering

18

longitudinal rib

19

guide element

19.1

guide pins

20

Schott sheet

21

supporting body

22

T-slot guidance

23

component

24

rear wall

25

guide rail

26

front wall

27

cleaning device

27.1

spray wand

28

room

29

guide surface

30

sealing element

30.1

sealing strip

31

longitudinal recess

32

injection

33

Air outlet gap

F

Force (arrow)

L

Running direction (arrow)

pA

Operating pressure (arrow)

pR

Pressure (arrow)

V

vertical

α

angle

Claims (18)

1. Blade (1) for flexibly supporting a wire (2) in the region of a twin-wire zone of a twin-wire section of a machine for producing a fibrous web, in particular a paper or board web, comprising a movable top strip (3), which extends transversely with respect to the running direction (L) of the wire (2) and over at least some regions of which the wire (2) slides during operation of the machine, a movable supporting strip (4) which is connected rigidly to the movable top strip (3), likewise extends transversely with respect to the running direction (L) of the wire (2) and is guided in a fixed structure (5), a fixed guide strip (6) which is rigidly arranged in the fixed structure (5) and which in turn extends transversely with respect to the running direction (L) of the wire (2), a flexible pressing device (8) which is arranged between the movable supporting strip (4) and the fixed guide strip (6) in order to displace the movable supporting strip (4) together with the movable top strip (3) between a rest position and an operating position, in which the movable top strip (3) can be pressed onto the wire (2) with a selectable force (F), and a flexible return device (11) for bringing the movable supporting strip (4) together with the movable top strip (3) out of the operating position into the rest position and for holding the two strips (3, 4) in the rest position,
   characterized in that
   the flexible return device (11) has a plurality of movable return bows (12) which are distributed over the length of the movable supporting strip (4), can be brought at one end (12.1), at least temporarily, into engagement with the movable supporting strip (4) and can be acted upon, at least temporarily, at the other end (12.2) by at least one return element (13) arranged in each case between the fixed guide strip (6) and the movable return bow (12).
2. Blade (1) according to Claim 1,
   characterized in that
   the movable supporting strip (4) has at least one depression, preferably a plurality of depressions (14), in which the one ends (12.1) of the movable return bow (12) can, at least temporarily, be brought into engagement.
3. Blade (1) according to Claim 1 or 2,
   characterized in that
   the respective return element (13) is formed as a return hose (15) that can be pressurized, at least temporarily, with a pressure (pR).
4. Blade (1) according to Claim 3,
   characterized in that
   the return hose (15) extends along the fixed guide strip (6), at least between the two return bows (12) at the edge.
5. Blade (1) according to Claim 3 or 4,
   characterized in that
   the return hose (15), over at least some regions with regard to its circumference (15U), in particular at least on the underside, is guided in a depression (16) made in the upper side of the fixed guide strip (6).
6. Blade (1) according to Claim 3, 4 or 5,
   characterized in that
   on the inside on one end (12.1) of the respective return bow (12) there is fitted a centring element (17), in particular a centring pin (17.1), which, at least temporarily, can be acted on by a longitudinal rib (18) fitted to the upper side of the return hose (15).
7. Blade (1) according to one of the preceding claims,
   characterized in that
   the return bow (12) is guided and limited on both sides by means of a plurality of guide elements (19), in particular guide pins (19.1), fitted in the fixed structure (5).
8. Blade (1) according to one of the preceding claims,
   characterized in that
   the fixed structure (5) comprises a plurality of preferably triangular sheet metal partitions (20) which are arranged both at a distance from one another on a supporting body (21) extending transversely with respect to the running direction (L) of the wire (2) and also in the region of the return bows (12) and which at least partly enclose at least the fixed guide strip (6) and the movable supporting strip (4) in the manner of a clip.
9. Blade (1) according to Claim 8,
   characterized in that
   on the side facing away from the sheet metal partitions (20), the supporting body (21) has a plurality of T-groove guides (22) for attaching the latter to a further component (23).
10. Blade (1) according to Claim 8 or 9,
    characterized in that
    on their side facing the wire (2), the sheet metal partitions (20) are provided with a rear wall (24) extending transversely with respect to the running direction (L) of the wire (2).
11. Blade (1) according to Claim 10,
    characterized in that
    the rear wall (24) is attached to the sheet metal partitions (20) by means of at least one guide strip (25).
12. Blade (1) according to one of Claims 8 to 11,
    characterized in that
    on their side facing away from the wire (2), the sheet metal partitions (20) are provided with a front wall (26) extending transversely with respect to the running direction (L) of the wire (2).
13. Blade (1) according to Claim 12,
    characterized in that
    between the front wall (26) and the movable supporting strip (4), at least over some distance, in particular between the sheet metal partitions (20), there are arranged sealing elements (30), in particular sealing strips (30.1), extending transversely with respect to the running direction (L) of the wire (2).
14. Blade (1) according to one of Claims 8 to 13,
    characterized in that
    in the upper region of the sheet metal partitions (20) there is arranged a cleaning device (27) extending transversely with respect to the running direction (L) of the wire (2), in particular a spray pipe (27.1), for cleaning the interior of the chamber (28) formed by the supporting body (21), the rear wall (24) and the front wall (26).
15. Blade (1) according to one of Claims 8 to 14,
    characterized in that
    at least one return bow (12) is provided with a preferably central longitudinal cut-out (31), in which the associated sheet metal partition (20) is guided, and
    in that the guide elements (19), in particular guide pins (19.1), for guiding the return bow (12) are fitted to the sheet metal partition (20).
16. Twin-wire section of a machine for producing a fibrous web, in particular a paper or board web,
    characterized in that
    it has a skimmer blade according to one of the preceding claims.
17. Twin-wire section of a machine for producing a fibrous web, in particular a paper or board web,
    characterized in that
    it has at least one dewatering blade according to one of the preceding Claims 1-15.
18. Twin-wire section according to Claim 17,
    characterized in that
    it has a plurality of dewatering blades arranged in the running direction (L) of the wire (2).

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