WO2004035918A1

WO2004035918A1 - Press arrangement

Info

Publication number: WO2004035918A1
Application number: PCT/EP2003/050338
Authority: WO
Inventors: Andreas Meschenmoser; Günter Kriechbaum; Helmut Störr; Ralf Henzler
Original assignee: Voith Paper Patent Gmbh
Priority date: 2002-10-11
Filing date: 2003-07-28
Publication date: 2004-04-29
Also published as: DE10247538A1; AU2003262542A1; EP1556542A1

Abstract

The invention relates to a press arrangement (10) for treating a web of material, especially a web of paper or card, comprising at least two successive press nips (12, 14) when seen in the running direction of said web (L). The first press nip (12), when seen in the running direction of the web (L), is formed between a press suction cylinder (16) and a counter press unit (18) and is double felted. The felt (20), which extends through the first press nip (12) on the side of the counter press unit (18), is separated from the web of material and the felt (22) which further transports it and which extends through the first press nip (12) on the side of the press suction cylinder (16) at the connection point with the first nip (12). Said press suction cylinder (16) comprises a suction area (44) which is arranged in the region of the first nip area (12), said suction area beginning after the first press nip (12) when seen in the peripheral direction of the press suction cylinder (16).

Description

Press arrangement

The invention relates to a press arrangement for treating a material web, in particular paper or cardboard web, with at least two press nips which follow one another in the web running direction, the first press nip, viewed in the web running direction, being formed and double-felted between a press suction roll and a counterpress unit, which is on the side of the counterpress unit separated by the first press nip following the first press nip from the material web and the felt that continues on the side of the press suction roll through the first press nip and the press suction roll comprises a suction zone provided in the area of the first press nip.

A press arrangement of the type mentioned at the outset is described, for example, in WO99 / 60203. In this known press arrangement, the suction zone of the press suction roll provided in the area of the first press nip extends from the felt run-up point in front of the nip to the run-off point after the nip. The first press nip is therefore completely within the suction zone. Such large suction zones now require unnecessary vacuum and can lead to so-called perforated shadow markings.

The invention has for its object to provide an improved press arrangement of the type mentioned, with which the disadvantages mentioned above are eliminated. According to the invention, this object is achieved in that the suction zone, viewed in the direction of rotation of the press suction roll, does not begin before the first press nip. When viewed in the direction of rotation of the press suction roll, a non-suctioned holding zone is preferably provided behind the suction zone, which is acted upon by the vacuum in the suction bores of the press suction roll in the area of the outlet gusset between the suction roll-side felt running off the press suction roll and the press suction roll and by the material web in the Area of the gusset is held on the draining felt. The length of the suction zone measured in the direction of rotation of the press suction roll is therefore reduced to a minimum, and it can only be used for web separation after the nip. The vacuum released in the holding zone is used to support the web position on the felt after the nip, which reduces the vacuum and accordingly the energy consumption. In addition, the development of noise is reduced.

By a ^"minimum reduced, designed exclusively for a secure web guiding active vacuum-suction zone is thus reduces the amount of required vacuum interpretation, due to the smaller open surface and the corresponding smaller amount of air leakage is reduced. As in the nip, the dewatering effect no longer is reinforced on one side by the vacuum, but instead an essentially symmetrical drainage takes place via the top and bottom felt, resulting in a lower tendency to perforate shadows. By slowly venting the suction holes in the press suction roll jacket through the holding zone, that is, the vacuum is slowly reduced This also results in a reduced noise level, in particular if, as described below in connection with a preferred embodiment, in the drain gusset between the drain from the press suction roll fenden suction roll-side felt and the press suction roll a wedge-like molded part is arranged, which ultimately acts as a sound absorption wedge. Perforated shadow marks are at least reduced by the more equilateral drainage without vacuum influence in the nip.

In an expedient embodiment of the press arrangement according to the invention, the suction zone, viewed in the circumferential direction of the press suction roll, begins at the latest at the separation point at which the felt provided on the side of the counter-press unit is separated from the material web and the other felt. When viewed in the direction of rotation of the press suction roll, the suction zone can begin, for example, in the last third of the first press nip. In principle, however, embodiments are also conceivable, for example, in which the suction zone, viewed in the direction of rotation of the press suction roll, begins at the earliest at the end of the first press nip.

In a preferred practical embodiment, the suction zone, viewed in the circumferential direction of the press suction roll, ends at the latest at the point at which the felt on the suction roll runs off the press suction roll. When viewed in the circumferential direction of the press suction roll, the suction zone can end, in particular, before the point at which the felt on the suction roll runs off the press suction roll.

The separation point of the felt provided on the side of the counter press unit is preferably behind the end of the first press nip. This separation point can be, for example, at or a few millimeters after the end of the nip. The point at which the felt on the suction roll side runs off the press suction roll is, viewed in the web running direction, preferably behind the separation point of the felt provided on the side of the counter-press unit.

In an expedient practical embodiment of the press arrangement according to the invention, a chamber which is adjacent to the inside of the press suction roll shell and is open towards the latter is provided in the region of the holding zone. This chamber is preferably only connected to the surroundings via the suction bores provided in the jacket of the press suction roll.

This chamber, which is assigned to the passive, that is to say not actively suctioned or vacuumed, holding zone serves in particular as a noise insulation chamber and vacuum intermediate chamber. In this way, the constantly arriving vacuum from the vacant suction bores in the holding zone can relax to a lower negative pressure compared to the environment in the chamber. The vacuum in the drain gusset between the press suction roll and the running felt is correspondingly reduced. During operation, the vacuum in the chamber is lower than in the suction zone.

Appropriately, the chamber begins in the direction of rotation of the press suction roll at the earliest at the point at which the suction roll-side felt runs off the press suction roll.

In an alternative expedient embodiment of the press arrangement according to the invention, the inside of the press suction roll casing is sealed in the region of the holding zone by an adjacent sealing element or the like. The chamber can therefore be omitted here. As already mentioned, a wedge-like molded part can advantageously be arranged in the drain gusset between the felt on the suction roll side running off the suction roll and the press suction roll. In this case, an outlet gap is preferably formed between the wedge-like molded part and the felt on the suction roll side running off the press suction roll and between the wedge-like molded part and the press suction roll. The wedge-like molded part can extend at least essentially over the entire machine width.

With such a wedge-like molded part, it is achieved, inter alia, that the differential pressure between the underside and top of the felt, through which the material web is pressed firmly onto the felt, persists even longer. The molded part can also serve as a water deflector for the press water thrown out of the suction bores of the press suction roll casing. The two outlet gaps are partly delimited on the one hand by the mold and on the other hand by a moving outlet element, i.e. the press suction roll or the felt running off of it, whereby air is constantly transported away from the two narrow outlet gaps, which leads to the creation of a vacuum in contributes to this area. In this way, for example, an additional web-holding suction device with a separate suction connection can be dispensed with.

The continuous web suction directly behind the first nip proves to be particularly advantageous with faster machines, since there is also a negative pressure in the opening gusset between the two felts, which causes an air flow from the sides to the center of the machine, which leads to a lifting of the edge of the material web from the bottom felt can. With the design according to the invention, edge tears and runs Avoidable losses. The paper or board machine in question can therefore also be operated in particular at higher speeds. The machine speed can be, for example, greater than or equal to 1000 m / min, in particular greater than or equal to 1200 m / min and preferably greater than or equal to 1800 m / min.

Continuous web maintenance on the felt can thus be achieved, in particular in connection with the molded part, using the vacuum conveyed from the suction roll without an additional suction box and without an additional connection. With the extended vacuum zone on the relevant side of the felt gusset, for example on its underside, there is better runnability. As already mentioned, the molded part can simultaneously serve as a water repellent and additionally act as a noise-absorbing body, since its installation position prevents the free escape of noise from the outlet gusset. The function of such a shaped wedge is described as such, for example, in the applicant's German patent application with the applicant's file number ΕC 1483 ".

The suction zone is expediently sucked through a suction box.

This can be arranged at least partially within the press suction roll.

The suction zone can be delimited in the circumferential direction of the press suction roll, in particular by sealing elements lying on the inside of the press suction roll casing. In the circumferential direction of the press suction roll, the chamber can in particular be correspondingly limited again by sealing elements lying on the inside of the press suction roll casing.

The sealing elements can preferably be pressed or pressed against the inside of the press suction roll casing.

According to a preferred embodiment, the sealing elements each extend at least essentially over the entire machine width.

The suction zone and / or the chamber can likewise each extend in the transverse direction at least across the material web width of the machine.

The sealing elements are advantageously arranged between the suction roll jacket and the suction box.

The suction zone and the chamber can be separated from one another, for example, by a common sealing element. The vacuum in the suction bores of the press suction roll jacket is somewhat reduced above this sealing element, but is nevertheless maintained. The actively suctioned or vacuumed suction zone can therefore be kept shorter by the distance from the start of the sealing element to the point at which the felt running on the side of the press suction roll runs through the first press nip from the press suction roll.

The counter press unit can be formed by a counter roll with a relatively rigid roll shell or by a shoe press unit his. In the latter case, in particular a shoe press roll can be provided.

In a preferred practical embodiment of the press arrangement according to the invention, the counterpress unit is arranged generally above the press suction roll and is provided as the upper felt and corresponding to the felt running on the side of the counterpress unit through the first press nip and the felt running on the side of the press suction roll as the lower felt.

A felt runs through the second press nip, which is guided in the direction of web travel in front of the second press nip around a pickup suction roll, in the area of which it takes over the material web from the felt running on the side of the press suction roll through the first press nip. In this case, a wedge-like molded part can advantageously be arranged again in the region of the gusset between the felt running off the pickup suction roll and the pickup suction roll. With such a molded part, an extension of the vacuum zone at the outlet on the felt side in question can in particular be extended again. A steam blower box is preferably provided in the area of the pickup suction roll and the molded part and / or in the vacuum zone extended by this on the side of the felt facing away from the molded part. The felt can in particular be an overhead felt.

For example, by installing a corresponding molded part after the suction zone of the second pickup suction roller, the vacuum zone at the outlet, for example above the felt, can be extended again, so that it makes sense to use a steam to arrange boxes, whereby another suction box can be dispensed with.

A transfer belt located at the bottom can also be guided through the second press nip, for example.

The second press nip is preferably formed by a shoe press.

The nip direction of the second press nip can be inclined by approximately 5 to 15 ° to the vertical in the running direction towards the outlet.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the drawing; in this show.

1 shows a schematic illustration of an exemplary embodiment of a press arrangement for treating a material web,

FIG. 2 shows an enlarged, more detailed partial representation of the first press nip of the press arrangement according to FIG. 1 formed between a suction press roll and a counter roll, FIG.

Fig. 3 is a representation comparable to FIG. 2, another

Embodiment of the press assembly and

FIG. 4 shows an enlarged, more detailed illustration of the web transfer area comprising the second pickup suction roll between the two presses of the press arrangement according to FIG. 1. 1 shows a schematic representation of a press arrangement 10 for treating a material web, preferably a fibrous web, which can in particular be a paper or cardboard web.

The press arrangement 10 comprises two press nips 12, 14 following one another in the web running direction L. The first press nip 12, viewed in the web running direction L, is formed between a press suction roll 16 and a counterpress unit, which in the present case is formed by a counter roll 18 with a relatively rigid roll shell is. Basically, as such a counterpress unit e.g. however, a shoe press unit and in particular a shoe press roller can also be provided.

The first press nip 12 is felted twice. The material web is thus guided between the upper felt 20 and the lower felt 22 through the first press nip 12.

In the web running direction L in front of the first press nip 12, the upper felt 20 is guided around a pickup suction roll 25, in the area of which it takes over the material web from a screen belt 26. The material web is then fed through the upper felt 20 to the first press nip 12, through which the lower felt 22 is also guided. The material web is guided between the upper felt 20 and the lower felt 22 through the first press nip 12.

Following the first press nip 12, the upper felt 20 is separated from the material web and the lower felt 22 which continues to feed it.

By means of the second press nip 14, the material web is passed between an overhead felt 28 and an underlying transfer belt 30. carried out. The felt 28 above is guided in the web running direction L in front of the second press nip 14 around a second pickup suction roller 32, in the area of which it takes over the material web from the bottom felt 22 of the suction press 16, 18.

In the present exemplary embodiment, the second press nip 14 is formed by a shoe press 34, which in the present case comprises an upper shoe press roller 36 and a lower counter roller 38.

The upper felt 28 of the second press 36, 38, here, for example, a shoe press, is separated from the material web and the transfer belt 30, which lies below it, after the second press nip 14.

Finally, the material web in the area of another pickup suction roll 40 is taken over by the transfer belt 30 through a drying screen 42. Through this drying wire 42, the material web is then fed, for example, to a first drying cylinder 44 and, when being guided, is passed into a pulper via a scraper 81.

FIG. 2 shows an enlarged, more detailed partial representation of the first press nip 12 of the press arrangement 10 according to FIG. 1 formed between the suction press roll 16 and the counter roll 18

As can best be seen from this FIG. 2, the press suction roll 16 comprises a suction zone 44 provided in the area of the first press nip 12, which, viewed in the direction of rotation U of the press suction roll 16, does not begin before the first press nip 12. When viewed in the direction of rotation U of the press suction roll 16, a non-suctioned holding zone 46 is provided behind the suction zone 44. In contrast to the suction zone 44, this holding zone 46 is therefore not actively subjected to vacuum. This holding zone 46 is only acted upon by the vacuum released in the area of the drain gusset 48 between the bottom felt 22 running off the press suction roll 16 and the press suction roll 16 in the suction bores 50 of the press suction roll 16. The holding zone 46 thus means that the material web is in the area of the drain gusset 48 held on the draining bottom felt 22.

The suction zone 44 begins in the direction of rotation U of the press suction roll 16, at the latest at the separation point C, at which the upper felt provided on the side of the counter roll 18 is separated from the material web and the lower felt 22. In the present exemplary embodiment, the suction zone 44 begins precisely at this separation point C. In the present case, the separation point C lies behind the end B of the first press nip 12 in the circumferential direction U of the press suction roll 16.

The suction zone 44 ends in the direction of rotation U of the press suction roll 16, viewed at the latest at point D, at which the bottom felt 22 runs off the press suction roll 16. In the present exemplary embodiment, it ends before this outlet point D. The actively suctioned or vacuumed suction zone 44 can thus be kept shorter by a corresponding distance, that is, there is an angle a (angle between the separation point C and the end of the suction zone 44 ), which is smaller than the angle b (angle between the end of the first press nip 12 and the outlet point D). As can be seen from FIG. 2, the bottom felt 22 runs off the press suction roll 16 clearly after the suction zone 44. The point D at which the bottom felt 22 runs off the press suction roll 16 is, viewed in the web running direction L, clearly behind the separation point C of the top felt 20.

Provided in the region of the holding zone 44 is a chamber 56 adjacent to the inside 54 of the press suction roll jacket 52 and open toward the latter. This chamber 56 is only in connection with the environment via the suction bores 50 provided in the jacket 52 of the press suction roller 16. The chamber 56 begins in the circumferential direction U of the press suction roll 16, considered at the earliest at point D at which the bottom felt 22 runs off the press suction roll 16.

The suction zone 44 is limited in the circumferential direction U of the press suction roll 16 by sealing elements abutting the inside 54, here for example sealing strips 58, 60. When viewed in the circumferential direction U of the press suction roll 16, the chamber 56 lies between the sealing strip 60 and a further sealing element 62, which can also be designed, for example, as a sealing strip.

The sealing elements or sealing strips 58 to 62 can be pressed or pressed against the inside 54 of the press suction roll shell 52. They can each extend at least essentially over the entire width of the machine.

The suction zone 44 is actively sucked through a suction box 64 through an opening 66 provided therein, or vacuumed. beat. The suction box 64 is at least partially arranged within the press suction roll 16.

The sealing elements or sealing strips 58 to 62 are arranged between the suction roll shell 52 and the suction box 64.

The press suction roll 16 of the suction press 16, 18 thus has a suction box 64 with an active vacuum suction zone 44 and a passive holding zone 56, to which a chamber 56 can be assigned, which simultaneously serves as a noise insulation chamber and vacuum intermediate chamber. The suction zone 4 and the holding zone 56 are delimited and sealed toward the press suction roll jacket 52 with sealing strips 58-62 that can be pressed on in particular. The suction zone 44 does not begin before the first press nip 12, so that false air and correspondingly unnecessary energy consumption are avoided. The first sealing strip 58 ends at the latest at the separation point C at which the upper felt 20 is separated from the material web and the lower felt 22. The theoretical separation point of the upper felt 20 is preferably at or a few millimeters after the end of the first press nip 12.

The first sealing strip 58 can be designed as a wide strip that covers the entire nip width.

The second sealing strip 60 is also preferably again designed as a wide strip, the end of this sealing strip 60 at the earliest at the outlet point D at which the bottom felt 22 runs off the press suction roll 16. Over the sealing strip 60, the vacuum in the suction bores 50 of the press suction roll casing 52 is somewhat reduced as far as the discharge point D, but is nevertheless maintained. The actively suctioned or vacuumed suction zone 44 can thus be moved the distance from the beginning of the Sealing strip 60 can be kept shorter up to drain point D. The angle between the separation point C and the end of the suction zone 44 is thus smaller than the angle b between the end B of the first press nip 12 and the outlet point D. The bottom felt 22 thus runs clearly after the suction zone 4 from the press suction roll 16.

The constantly arriving vacuum from the vacant suction bores 50 after the discharge point D or at the end of the sealing strip 60 now relaxes to a lower negative pressure in relation to the environment in the chamber 56 and thus in the outlet gusset 48 between the press suction roller 16 and the bottom felt 22.

Since the chamber 56 is only connected to the surroundings via the suction bores 50 of the press suction roll casing 52, a lower vacuum is established in the chamber 56 than in the suction zone 44 during operation.

So that the differential pressure between the underside and top of the felt, which presses the material web firmly onto the bottom felt 22, remains even longer, a wedge-like molded part 68 is installed in the outlet gusset 48 between the bottom felt 22 running off the press suction roll 16 and the press suction roll 16. This molded part preferably extends at least essentially over the entire machine width and at the same time also serves as a water deflector for the press water thrown out of the suction bores 50.

An outlet gap 70 or 72 is formed between the wedge-like shaped part 68 and the bottom felt 22 running off the press suction roll 1 and between the wedge-like shaped part 68 and the press suction roll 16. After both outlet gaps 70, 72 are delimited on one side in the form of the bottom felt 22 or in the form of the press suction roller 16 by a moving outlet element, air is constantly transported from the respective outlet gap 70 or 72, which creates a negative pressure contributes in the areas concerned. In this way, there is no need for an additional suction box with a separate suction connection.

3 shows a representation of a further embodiment of the press arrangement, comparable to that of FIG. 2, in which the inside 54 of the press suction roll casing 52 in the area of the holding zone 46 is sealed by an adjacent sealing element or strip 60 ′ which simultaneously delimits the suction zone 44, which is correspondingly extended in the circumferential direction U of the press suction roll 16. In this case, the sealing element or sealing strip 60 'which simultaneously defines the end of the suction zone 44 extends over an angular range d. The chamber 56 can therefore be omitted in this case.

FIG. 4 shows, in an enlarged, more detailed partial representation, the web transfer area comprising the second pickup suction roller 32 between the two presses of the press arrangement 10 according to FIG. 1.

A particularly wedge-like molded part 76 is then arranged in the region of the drain gusset 74 between the felt 28 running off the pickup suction roller 32 and the pickup suction roller 32. A steam blower box 78 is provided in the area of this molded part 76 or in the area of the vacuum zone extended by this on the side of the felt 28 facing away from the molded part 76. By installing the molded part 76 after the suction zone 80 of the second pickup suction roller 32, the vacuum zone at the outlet above the felt 28 can also be lengthened, so that it makes sense to arrange a steam blow box 78 below this point without the need for a further suction box would.

LIST OF REFERENCE NUMBERS

Press arrangement first press nip second press nip press suction roll counter press unit, counter press roll top felt bottom felt pick up suction roll screen belt felt transfer belt pick up suction roll shoe press shoe press roll counter roll pick up suction roll drying sieve suction zone holding zone drain gusset suction hole press suction roll jacket inside chamber sealing element, sealing element sealing strip, sealing strip, sealing strip 62 sealing element, sealing strip

64 suction box

66 opening

68 wedge-like molded part 70 outlet gap

72 outlet gap

74 drain gusset

76 wedge-like molded part

78 steam blowing unit 80 suction zone

81 scrapers

B End of the first press nip

C separation point

D Discharge point L web direction

U circumferential direction of the press suction roll

Claims

Patent claims

1. Press arrangement (10) for treating a material web, in particular paper or cardboard web, with at least two press nips (12, 14) which follow one another in the web running direction (L), the first press nip (12) between a press suction roll viewed in the web running direction (L) (16) and a counterpress unit (18) is formed and double felted, the felt (20) running on the side of the counterpress unit (18) through the first press nip (12) following the first press nip (12) from the material web and the this further leading felt (22) running on the side of the press suction roll (16) is separated by the first press nip (12) and the press suction roll (16) comprises a suction zone (44) provided in the region of the first press nip (12), characterized in that that the suction zone (44) in the transfer direction (U) of the press suction roll

(16) does not consider before the first press nip (12) begins.

2. Press arrangement according to claim 1, characterized in that viewed in the circumferential direction (U) of the press suction roll (16) behind the suction zone (44) a non-suction holding zone (46) is provided, which in the area of the drain gusset (48) between the from the press suction roll (16) draining suction roll-side felt (22) and the press suction roll (16) released vacuum in the suction bores (50) of the press suction roll (16) and through which the material web is held in the region of the drain gusset (48) on the felt that runs off.

3. Press arrangement according to claim 1 or 2, characterized in that the suction zone (44) viewed in the circumferential direction (U) of the press suction roll (16) begins at the latest at the separation point (C) at which the provided on the side of the counter-press unit (18) Felt (20) is separated from the material web and the other felt (22).

4. Press arrangement according to one of the preceding claims, characterized in that the suction zone (44), viewed in the circumferential direction (U) of the press suction roll (16), begins in the last third of the first press nip (12).

5. Press arrangement according to one of the preceding claims, characterized in that the suction zone (44) in the circumferential direction (U) of the press suction roll (16) viewed at the earliest at the end (B) of the first press nip (12) begins.

6. Press arrangement according to one of the preceding claims, characterized in that the suction zone (44) in the circumferential direction (U) of the press suction roll (16) ends at the latest at the point (D) at which the suction roll-side felt (22) of the press suction roll ( 16) expires.

7. Press arrangement according to claim 6, characterized in that the suction zone (44) in the circumferential direction (U) of the press suction roll (16) viewed before the point (D) ends at which the suction roll-side felt (22) runs off the press suction roll (16).

8. Press arrangement according to one of the preceding claims, characterized in that the separation point (C) of the felt (20) provided on the side of the counterpressing unit (18) lies behind the end (B) of the first press nip (12).

9. Press arrangement according to one of the preceding claims, characterized in that the point (D) at which the suction roll-side felt (22) from the press suction roll (16) runs, viewed in the web running direction (L) behind the separation point (C) on the The side of the counterpressing unit (18) provided felt (20).

10. Press arrangement according to one of the preceding claims, characterized in that in the region of the holding zone (44) there is provided a chamber (56) adjacent to the inside (54) of the press suction roll casing (52) and open towards it.

11. Press arrangement according to claim 10, characterized in that the chamber (56) only communicates with the surroundings via the suction bores (50) provided in the casing (52) of the press suction roll (16).

12. Press arrangement according to claim 10 or 11, characterized in that that the chamber (56) in the direction of rotation (U) of the press suction roll (16) begins at the earliest at the point (D) at which the suction roll-side felt (22) runs off the press suction roll (16).

13. Press arrangement according to claims 1 to 10, characterized in that the inside (54) of the press suction roll casing (52) is sealed in the region of the holding zone (46) by an adjacent sealing element (60 ') or the like.

14. Press arrangement according to one of the preceding claims, characterized in that a wedge-like molded part (68) is arranged in the outlet gusset (48) between the suction roll-side felt (22) running off the press suction roll (16) and the press suction roll (16).

15. Press arrangement according to claim 14, characterized in that between the wedge-shaped part (68) and from the press suction roll (16) running on the suction roll-side felt (22) and between the wedge-shaped part (68) and the press suction roll (16) each have an outlet gap ( 70, 72) is formed.

16. Press arrangement according to claim 14 or 15, characterized in that the wedge-like shaped part (68) extends at least substantially over the entire machine width.

17. Press arrangement according to one of the preceding claims, characterized in that the suction zone (44) is suctioned via a suction box (64).

18. Press arrangement according to claim 17, characterized in that the suction box (64) is arranged at least partially within the press suction roll (16).

19. Press arrangement according to one of the preceding claims, characterized in that the suction zone (44) is delimited in the circumferential direction (U) of the press suction roll (16) by sealing elements (58, 60) abutting the inside (54) of the press suction roll casing (52).

20. Press arrangement according to one of the preceding claims, characterized in that the chamber (56) is delimited in the circumferential direction (U) of the press suction roll (16) by sealing elements (60, 62) abutting the inside (54) of the press suction roll casing (52).

21. Press arrangement according to claim 19 or 20, characterized in that the sealing elements (58-62) can be pressed or pressed onto the inside (54) of the press suction roll casing (52).

22. Press arrangement according to one of the preceding claims, characterized in that the sealing elements (58-62) each extend at least substantially over the entire machine width.

23. Press arrangement according to one of the preceding claims, characterized in that the suction zone (44) and / or the chamber (56) each extend at least across the width of the material web.

24. Press arrangement according to one of the preceding claims, characterized in that the sealing elements (58-62) are arranged between the suction roll jacket and the suction box (64).

25. Press arrangement according to one of the preceding claims, characterized in that the suction zone (44) and the chamber (56) are separated from one another by a common sealing element (60).

26. Press arrangement according to one of the preceding claims, characterized in that the sealing elements (58-62) are formed by sealing strips.

27. Press arrangement according to one of the preceding claims, characterized in that the inside (54) of the press suction roll casing (52) is sealed in the region of the holding zone (46) by an adjacent sealing element (60 ') which delimits the suction zone (44) at the same time is extended accordingly in the circumferential direction of the press suction roll (16).

28. Press arrangement according to one of the preceding claims, characterized in that that the counter press unit (18) is formed by a counter roll with a relatively rigid roll shell.

29. Press arrangement according to one of claims 1 to 27, characterized in that the counterpress unit (18) is formed by a shoe press unit.

30. Press arrangement according to claim 29, characterized in that a shoe press roller is provided as the shoe press unit.

31. Press arrangement according to one of the preceding claims, characterized in that the counterpress unit (18) is arranged generally above the press suction roll (16) and corresponding to the felt running on the side of the counterpress unit (18) through the first press nip (12) as an upper felt (20 ) and the felt running on the side of the press suction roll (16) through the first press nip (12) is provided as a bottom felt (22).

32. Press arrangement according to one of the preceding claims, characterized in that a felt (28) runs through the second press nip, which is guided in the web running direction before the second press nip (14) around a pickup suction roll (32), in the area of which it Material web takes over from the felt (22) running on the side of the press suction roll (16) through the first press nip (12).

33. Press arrangement according to claim 32, characterized in that in the region of the drain gusset (74) between the felt (28) running off the pickup suction roll (32) and the pickup suction roll (32) a particularly wedge-like molded part (76) is arranged ,

34. Press arrangement according to claim 33, characterized in that in the region of the pickup suction roller (32) and the molded part (76) and / or in the region of the vacuum zone extended by this on the side of the felt (28) facing away from the molded part (76) ) a steam blower box (78) is provided.

35. Press arrangement according to one of claims 32 to 34, characterized in that the felt (28) is an overhead felt.

36. Press arrangement according to one of the preceding claims, characterized in that a transfer belt (30) lying underneath is guided through the second press nip (14).

37. Press arrangement according to one of the preceding claims, characterized in that the second press nip (14) is formed by a shoe press.

38. Press arrangement according to one of the preceding claims, characterized in that the nip direction of the second press nip (14) is inclined by approximately 5 to 15 ^c to the vertical in the running direction towards the outlet.