EP1022380A2 - Pressing arrangement - Google Patents

Abstract

The press section for a wet paper or cardboard fiber web has at least two roller press gaps (S1,S2) in succession along the web movement path direction (L). The first roller press gap has two blankets moving through it with the web. The press section for a wet paper or cardboard fiber web has at least two roller press gaps (S1,S2) in succession along the web movement path direction (L). The first roller press gap has two blankets moving through it with the web. The first, extended press gap (S1) is formed between a shoe press unit (20) and a pick-up roller which is, at the same time, a suction press roller (12) with a blanket (14) round it to detach the web (10) from a fourdrinier (16) as it passes through the first roller press gap (S1). The shoe press unit is formed by a lower shoe press roller (20), common to both press gaps (S1,S2), working together with a further upper counter roller (24) as well as the suction press roller (12). The shoe press roller (20) has a roller mantle with position stability The roller press gaps (S1,S2) can be formed by two separate shoe presses, each with a shoe press roller together with a pick-up/suction press roller (12) and a counter roller (24). Each shoe press roller is below the web, and the pick-up/suction press roller and the counter roller are over the web. The fiber web (10) passes between the two extended roller press gaps (S1,S2) round a suction deflection roller (36), preferably together with a blanket (18). The blanket (18) is moved through both extended roller press gaps (S1,S2). Each extended roller press gap (S1,S2) has two blankets moving through, together with the web and, in total, a maximum of three blankets (14,18,26) are used in the press section. The blankets travel in a closed path. The second roller press gap (S2) can have a single blanket through it in a press section using max. two blankets (14,18). The web (10) is between its blanket (18) and the counter roller (24), through the second extended roller press gap (S2) and the counter roller (24) has a closed mantle surface. At least part or all of the press surfaces of the press rollers (12,20,24) have a profiled structure of ridges and/or blind drillings. The fiber web (10) follows a free path after the final roller press gap (S2) from the trailing counter roller (24) round a suction deflection roller (30), to be picked up by a blanket (32) round it to be carried onwards, and preferably to the drying section of the machine. The water extraction from the web, at least at one of the extended roller press gaps (S1,S2), is through spinning out the water at least partially into at least one trough (72,74,76,78) and the like. At least one counter roller (24) and/or the press suction roller (12), and especially the trailing counter roller (24), are formed by a hollow roller with an inner support, and preferably as a bending compensation roller.

Description

The invention relates to a press arrangement for treating a fibrous web, especially a paper or cardboard web.

The aim of the invention is a press arrangement of the aforementioned Art to create that with the most compact design and low manufacturing costs in particular, a volume-saving drainage guaranteed.

This object is achieved according to the invention in that at least two press gaps, one behind the other, extended in the direction of web travel are provided, of which at least the first is double felted, and that the first extended press nip between a shoe press unit and a press suction roll provided at the same time as a pick-up roll is that of a web belt taking over the fibrous web Felt is wrapped through which the fibrous web is extended to the first Press nip is guided.

In a preferred embodiment of the press arrangement according to the invention is the shoe press unit by one below, two extended press nips formed common shoe press roll, the except the press suction roll is assigned a further top roll.

Such a two comprehensive press nips extended in the web running direction Press arrangement is inexpensive to manufacture. There is no mutual Line force influence on, so that a crowning of the rollers is not necessary. Volume-saving drainage is guaranteed. In addition there is a flat gradient, which means that in the two Press gaps in the Z direction set a slower flow rate. Overall, optimal nip or gap drainage is achieved. After the web has been removed from the wire by a press roller provided suction roll takes place, is an extremely compact overall Construction reached. The two presses can in particular be carried out without a lever be, which means that a respective pressing in particular done by a respective hydraulic pressure shoe, whereby a closed power flow is achieved within the frame.

The shoe press roll is preferably with a positionally stable press jacket guide provided, thereby regardless of the respective operating conditions always ensures optimal web and / or felt guidance is.

In a further advantageous embodiment variant, the two are elongated Press nips formed by two separate shoe presses. Here the two shoe presses each preferably comprise a shoe press roll, the two elongated press nips then by the respective Shoe press roll and the press suction roll provided at the same time as the pick-up roll or a further counter roll are formed.

The fibrous web can between the two elongated press nips preferably together with a felt around a preferably as a suction roll trained deflection roller to be guided.

A felt is expediently passed through both elongated press nips.

In an expedient and practical embodiment of the invention Press arrangement are both elongated in the direction of web travel Press nips felted twice. This results in a low one Bilateralism. There are no press roll scrapers in the area of the second counter roll required. In addition, the path is completely closed from sieve to dryer section possible. Overall are advantageous A maximum of three felts are provided.

In a further advantageous embodiment of the invention Press arrangement is the second elongated viewed in the direction of web travel Press nip simply felted. In this case, two felts are sufficient, if one of these felts is passed through both press nips at the same time.

At least part of the two advantageously has in the direction of web travel extended press nips each forming an open, especially blind bored and / or grooved press surface.

Are both press nips elongated in the web running direction double each felted, so all press rolls can each have an open press surface.

If the second extended press nip is simply felted, it has one Shoe press unit forming this second press nip rear counter roll expediently an at least substantially closed pressing surface. Such a smooth counter roll is for certain products such as Liner with white top ("White Top") suitable.

In a preferred embodiment, the drainage takes place at least of an extended press nip at least partially by spinning off of water in at least one gutter or the like.

It is also advantageous if at least one counter roller and / or the Press suction roll is formed by an internally supported hollow roll.

In the dependent claims, further advantageous embodiments of the Press arrangement according to the invention specified.

Fig. 1

eine schematische, teilweise geschnittene Darstellung einer ersten Ausführungsform einer zwei verlängerte Preßspalte aufweisenden Pressenanordnung, bei der sowohl der erste als auch der zweite verlängerte Preßspalt jeweils doppelt befilzt ist,

Fig. 2

eine schematische, teilweise geschnittene Darstellung einer weiteren Ausführungsform einer Pressenanordnung, bei der der erste verlängerte Preßspalt doppelt und der zweite verlängerte Preßspalt einfach befilzt ist,

Fig. 3

eine detailliertere Querschnittsdarstellung einer in der Pressenanordnung gemäß Fig. 1 oder 2 verwendbaren positionsstabilen Schuhpreßwalze,

Fig. 4

eine detailliertere Querschnittsdarstellung einer weiteren Ausführungsform einer in der Pressenanordnung gemäß Fig. 1 oder 2 verwendbaren positionsstabilen Schuhpreßwalze,

Fig. 5

eine schematische, teilweise geschnittene Darstellung einer Ausführungsform einer zwei getrennte Schuhpressen aufweisenden Pressenanordnung, bei der sowohl der erste als auch der zweite verlängerte Preßspalt jeweils doppelt befilzt ist, und

Fig. 6

eine schematische, teilweise geschnittene Darstellung einer Ausführungsform einer zwei getrennte Schuhpressen aufweisenden Pressenanordnung, bei der der erste verlängerte Preßspalt doppelt und der zweite verlängerte Preßspalt einfach befilzt ist.

The invention is explained below using exemplary embodiments with reference to the drawing; in this show:

Fig. 1

2 shows a schematic, partially sectioned illustration of a first embodiment of a press arrangement having two elongated press nips, in which both the first and the second elongated press nip are each felted twice,

Fig. 2

2 shows a schematic, partially sectioned illustration of a further embodiment of a press arrangement, in which the first extended press nip is double felted and the second extended press nip is simply felted,

Fig. 3

2 shows a more detailed cross-sectional illustration of a position-stable shoe press roll that can be used in the press arrangement according to FIG. 1 or 2,

Fig. 4

2 shows a more detailed cross-sectional representation of a further embodiment of a positionally stable shoe press roll which can be used in the press arrangement according to FIG. 1 or 2,

Fig. 5

is a schematic, partially sectioned illustration of an embodiment of a press arrangement having two separate shoe presses, in which both the first and the second elongated press nip are each felted twice, and

Fig. 6

is a schematic, partially sectioned representation of an embodiment of a press arrangement having two separate shoe presses, in which the first elongated press nip is double felted and the second elongated press nip is simply felted.

Fig. 1 shows a purely schematic, partially sectioned representation first embodiment of a press arrangement for treating a Fibrous web 10, which is in particular a paper or Cardboard web can act.

The fibrous web 10 is in the area of a press suction roll 12 by a Oberfilz 14 taken from a wire 16 and then together with a bottom felt 18 a first in the web running direction L extended press nip S1 supplied. Following this, the fibrous web 10 together with the bottom felt 18 a second in the web running direction L fed press nip S2.

As can be seen in FIG. 1, the two are in the direction of web travel L extended press gaps S1 and S2 between one below Shoe press roll 20 and the press suction roll 12 or another counter roll or press roll 24 formed above. The first double felted elongated press nip S1 is thus between the shoe press roll 20th and the press suction roll 12 which is simultaneously provided as a pick-up roll educated.

The rear counter or press roll 24 can be supported on the inside. So can this rear press roller 24, for example, a Deflection compensation roller act (see also Fig. 3). While the Press suction roll 12 obliquely left above the shoe press roll 20th is arranged, the further press roller 24 is obliquely right above the Shoe press roll 20 provided. The press roller 24 can advantageously are slightly higher than the press suction roller 12. Following the the second press nip S2 extended in the web running direction L becomes the fibrous web 10 in the region of a deflection roller designed as a suction roller 30 taken over by a drying wire 32 and the first drying cylinder 34 fed to a dryer section.

The fibrous web 10 is connected to the first extended press nip S1 passed around a suction roller 36 together with the bottom felt 18, before being taken over by the press roll 24 and extended by the second Press nip S2 is supplied. The result is a continuous one closed web guidance, namely from the takeover of the fibrous web 10 through the upper felt 14, which also serves as a pick-up felt Sieve web 16 until delivery to the dryer section.

In the present exemplary embodiment, the second is also extended Press gap S2 felted twice. A further top felt 26 is provided for this purpose, guided around the upper right press roll 24 in the manner shown is and following the second extended press nip S2 again by the fibrous web 10 is separated. The fibrous web 10 is thus between the lower felt 18 and the upper felt 26 extended by the second Press nip S2 performed.

The embodiment of a press arrangement shown in FIG. 2 differs differs from that of FIG. 1 by the fact that the second elongated press nip S2 is simply felted. It is also in the present case, the bottom felt 18 by both extended press nips S1, S2 led. In contrast, that in the embodiment according to FIG. 1 provided, the upper roll wrapping around the press roll 24. As shown in 2 can be seen, the fibrous web 10 is following the second extended press nip S2 in free pull from the rear counter or press roll 24 to a deflecting roll 22 and via this to the first Drying cylinder 34 guided the dryer section.

3 is an embodiment of one in the press arrangement usable position stable shoe press roll 20 shown. After that includes the shoe press roller 20 located at the bottom against one of its ends Twist secured outer hollow beam 80, one around the hollow beam 80 circumferential flexible press jacket 82 and two support devices 84, through which the press jacket 82 in the area of the two press gaps S1 and S2 is supported on the inside.

The outer hollow carrier 80 which guides the press jacket 82 is also a Assigned non-rotatably mounted inner carrier 86. Here is the press jacket 82 by means of the two support devices 84 through the jacket of the Hollow support 80 is supported directly on the inner support 86.

The support devices 84 each comprise at least one on the outside Hollow beam 80 guided press shoe 88 and several in a row across to the web running direction L arranged support elements 90 through which the Press shoe 88 is supported directly on the inner carrier 86. The Support elements 90 have radially inner, on or in the inner carrier 86 guided pistons 92. These support elements are at the radially outer end 90 coupled to the press shoe 88 via a respective joint. By the two supporting devices 84 applied supporting forces are preferred variable and in particular by a Delta-P valve 94 in particular can also be set separately (see FIG. 3).

The hollow support 80 and the inner support 86 are lateral at their ends Supports or stands preferably stored equidistant from one another. The bearings of the shoe press roll 20 arranged below are located and the two upper press rolls 12, 24 on the two Pages on a common level.

Bearing bushes can be pushed onto the two ends of the inner carrier 86 be that have a spherical outer bearing surface and in one appropriately trained recording of the respective stand added are. The ends are formed by the spherical bearings of the inner support 44 relative to the hollow support fixedly mounted on the stands 80 tiltable so that the inner support 86 can be bent freely can.

In the illustrated embodiments, not only has the press suction roll 12, but also the shoe press roll 20 has an open pressing surface. For example, the press jacket of the shoe press roll 20 can in particular be blind drilled and / or grooved.

In the embodiment shown in Fig. 1 also has the rear Press roll 24 an open, especially blind drilled and / or grooved Pressing surface. In contrast, in the embodiment shown in FIG. 2 with simply felted second press nip S2 is the rear upper Press roll 24 with an at least substantially closed surface Mistake.

The extended press nip S1 is drained by centrifuging of water in channels 72, 74 (see. Fig. 1 and 2), which by the open press surfaces of the press rolls 12, 20 is possible. As with the 1 and 2 can be seen, takes place after the first extended press nip S1 on both sides such drainage by centrifuging of water, for which the two channels 72, 74 on different Sides of the fibrous web 10 are arranged.

In the embodiment according to FIG. 1, in which the second also extended Press nip S2 is felted twice, is also the one at the top Press roll 24 drilled blind and / or grooved. In this case the second extended press nip S2 dewatered by centrifuging water, which is caught here by gutters 76, 78. In this case, too there is again double-sided drainage by such centrifuging of water, for which purpose the two channels 76, 78 on different Sides of the fibrous web 10 led out of the press nip S2 are provided are.

A web separating device can follow the second extended press nip S2 66 may be provided. This can be a suction cup 66 or a Suction roller 66 ', through which the fibrous web 10 in the area the separation point is sucked away from the upper felt 26 onto the lower felt 18.

In particular, the trough 72 can in principle also be used as a combined trough and web holding box may be provided.

In the area of the rear upper press roll 24 according to the embodiment Fig. 2, for example, a scraper or the like is provided.

In Fig. 3 is also one of the rear press roll 24 associated inner Support device 56 to recognize.

The upper press rolls 12, 24 are driven.

Fig. 4 shows a more detailed cross-sectional view of another Embodiment of one in the press arrangement according to FIGS. 1 and 2 usable position stable shoe press roll 20 '. In this case includes the shoe press roller 20 'located underneath a non-rotatably mounted hollow carrier 38, a flexible around the hollow carrier 38 Press jacket 40 and two in the circumferential direction a distance from each other having outer support devices 42, via which the press jacket 40th in the area of the two elongated press gaps S1 and S2 on the hollow beam 38 is supported.

The outer hollow carrier 38 is a likewise non-rotatably mounted inner carrier 44 assigned to which the hollow support 38 on the inside via a support device 46 is supported so that one by the differently directed Pressing forces in the area of the two extended press nips S1 and Resulting deflection generated S2 at least substantially compensated becomes.

The inner one arranged between the hollow carrier 38 and the inner carrier 44 Support device 46 comprises at least one transverse to the web running direction L extending row of support members 48. The two outer Support devices 42 each have at least one press shoe 50 and in each case again several in a direction extending transversely to the web running direction L. Row arranged support elements 52. In the present case each of the support members 48 and 52 each includes at least one cylinder / piston unit. The direction of action of the inner support device 46 lies in the resulting direction of action of the two outer support devices 42.

In the present embodiment, the two outer Support devices 42 applied support forces at least substantially same size. The radial directions of action are the two outer ones Support devices 42 preferably offset by approximately 120 °. The The direction of action of the inner support device 46 lies in the bisector of the angle between the two radial directions of action of the two outer Support devices 42. In the present case, the two outer Support devices 42 and the inner support device 46 applied Forces at least essentially the same size, so that they are a form an equilateral triangle of forces. The rows of support elements also have this of the two outer supports 42 and the inner support 46 an equal division. In addition, their support elements 42, 48 same piston surfaces.

The two outer supports 42 and the inner support 46 are, for example, preferably variably adjustable by the same Pressure can be applied.

The forces exerted by the three support devices 42, 46 are thus in balance. For the inner support of the upper press rolls 12, 24 provided support devices (cf. also Fig. 3) can by the same pressure as the outer supports 42 of the bottom Shoe press roller 20 'to be applied.

As can be seen from FIG. 4, there are 38 between the hollow carrier and the press jacket 40 further provided jacket guide strips 58, through which the press jacket 40 in the circumferential direction between the Press shoes 50 areas is guided accordingly.

With the use of such a position-stable shoe press roll 20 ' accordingly, the deflection of the hollow beam 38 through the inner Support device 46 influenced so that one by the forces in the area the two press nips S1 and S2 generated deflection at least in is substantially compensated. So that the hollow beam 38 is no longer on bending in the cross machine direction, but only on shell deformation claimed.

Fig. 5 shows a schematic, partially sectioned representation Embodiment of a press arrangement having two separate shoe presses, where both the first S1 and the second extended Press nip S2 is felted twice.

This embodiment according to FIG. 5 thus differs from that of Fig. 1 essentially in that instead of the common Shoe press roll 20 separate shoe press rolls 20 ", 20" 'for the extended ones Press gaps S1 and S2 are provided. In the present case includes the first shoe press is the one intended as a pick-up roller Press suction roll 12 and the shoe press roll 20 ". The second Shoe press is by the shoe press roll 20 "'and the associated counter or press roll 24 formed. The bottom felt 18 is here again passed through both press nips S1 and S2. The upper felt 14 is through the Press nip S1 and the upper felt 26 passed through the press nip S2. The Here, too, drainage takes place via channels 72 to 78. Also in the rest of the structure is at least essentially the same as in the Embodiment according to FIG. 1.

The embodiment according to FIG. 6 differs from that of FIG. 5 essentially in that the second extended press nip S2 only is simply felted. Just as in the embodiment according to FIG. 2 The upper felt 26 is therefore also omitted here in accordance with the embodiment 2 has the rear counter or press roller 24 again a closed press surface. In addition, also in the present case the fibrous web following the second extended press nip S2 again in free train from the rear press roller 24 to a deflecting roller 22 and led to the following dryer section.

Compared to the embodiment according to FIG. 2 are also in the present Case instead of the common shoe press roll 20 again two separate shoe press rolls 20 ", 20" 'provided. Otherwise has this Embodiment according to FIG. 6 at least essentially the same Structure like that of Fig. 2, with corresponding parts again same reference numerals are assigned.

Reference list

10th

Fibrous web

12th

Press suction roll

14

Top felt

16

Screen belt

18th

Bottom felt

20th

Shoe press roll

20 '

Shoe press roll

20 "

Shoe press roll

20 "'

Shoe press roll

22

Deflection roller

24th

Press roll

26

Top felt

30th

Deflection roller

32

Dryer fabric

34

Drying cylinder

36

Suction roll

38

Hollow beam

40

flexible press jacket

42

external support devices

44

Inner beam

46

inner support devices

48

Support elements

50

Press shoe

56

Support device

58

Jacket guide strips

64

scraper

66

Web cutting device

72

Gutter

74

Gutter

76

Gutter

78

Gutter

80

Hollow beam

82

flexible press jacket

84

Support devices

86

Inner beam

88

Press shoe

90

Support elements

L

Web direction

S1

first extended press nip

S2

second extended press nip

Claims (25)

Press arrangement for treating a fibrous web (10), in particular a paper or cardboard web,
characterized by
that at least two press nips (S1, S2), one behind the other, elongated in the web running direction (L) are provided, of which at least the first is double felted, and that the first extended press nip (S1) between a shoe press unit (20, 20 ', 20 ") and a press-suction roll (12) provided at the same time as a pick-up roll, which is wrapped by a felt (14) taking over the fibrous web (10) from a wire belt (16), through which the fibrous web (10) to the first extended press nip (S1) is performed. Press arrangement according to claim 1,
characterized by
that the shoe press unit is formed by a shoe press roll (20, 20 ') located at the bottom, which is extended by two extended press nips and which, in addition to the press suction roll (12), is assigned a further counter roll (24) located at the top. Press arrangement according to claim 2,
characterized by
that the shoe press roll (20, 20 ') is provided with a positionally stable press jacket guide. Press arrangement according to claim 1,
characterized by
that the two elongated press nips (S1, S2) are formed by two separate shoe presses (20 ", 12; 20"', 24). Press arrangement according to claim 4,
characterized by
that the two shoe presses (20 ", 12; 20"', 24) each comprise a shoe press roll (20 ";20"') and the two extended press nips (S1, S2) by the respective shoe press roll (20 ";20"') and the press suction roll (12) or a further counter roll (24) provided at the same time as a pick-up roll are formed. Press arrangement according to claim 5,
characterized by
that at least one of the two shoe presses (20 ", 12; 20"', 24) is formed by a shoe press unit (20 ";20"') located at the bottom and an opposing roller (12; 24) located at the top. Press arrangement according to claim 6,
characterized by
that both shoe presses (20 ", 12; 20"', 24) are each formed by a shoe press roll (20 ";20"') and an opposing roll (12; 24) located at the bottom. Press arrangement according to claim 5,
characterized by
that at least one of the two shoe presses is formed by an upper shoe press unit and a lower roller. Press arrangement according to one of the preceding claims,
characterized by
that the fibrous web (10) between the two elongated press nips (S1, S2) is preferably guided together with a felt (18) around a deflection roller (36), which is preferably designed as a suction roller. Press arrangement according to one of the preceding claims,
characterized by
that a felt (18) is passed through both elongated press nips (S1, S2). Press arrangement according to one of the preceding claims,
characterized by
that both press nips (S1, S2) elongated in the web running direction (L) are each felted twice. Press arrangement according to claim 11,
characterized by
that a maximum of three felts (14, 18, 26) are provided. Press arrangement according to claim 11 or 12,
characterized by
that it has a continuously closed web guide. Press arrangement according to one of claims 1 to 10,
characterized by
that the second elongated press nip (S2) viewed in the direction of web travel (L) is simply felted. Press arrangement according to claim 14,
characterized by
that a maximum of two felts (14, 18) are provided. Press arrangement according to claim 14 or 15,
characterized by
that the fibrous web (10) is guided between the relevant felt (18) and the rear counter-roller (24) through the second extended press nip (S2). Press arrangement according to one of the preceding claims,
characterized by
that at least some of the press rolls (12, 20, 24) forming the two press nips (S1, S2) extended in the web running direction (L) each have an open, in particular blind-drilled and / or grooved press surface. Press arrangement according to claim 17,
characterized by
that both press nips (S1, S2) elongated in the web running direction (L) are each felted twice and all press rolls (12, 20, 24) each have an open, in particular blind-drilled and / or grooved press surface. Press arrangement according to claim 17,
characterized by
that the second elongated press nip (S2) is simply felted and that with a shoe press unit (20, 20 "') forming this second press nip (S2) rear counter-roller (24) has an at least substantially closed press surface. Press arrangement according to claim 19,
characterized by
that the fibrous web (10) following the second extended press nip (S2) in free train from the rear counter-roller (24) to a deflection roller (22) and is preferably guided to a subsequent dryer section. Press arrangement according to one of the preceding claims,
characterized by
that the dewatering of at least one elongated press nip (S1, S2) takes place at least partially by spinning water into at least one trough (72-78) or the like. Press arrangement according to one of the preceding claims,
characterized by
that at least one counter roller (24) and / or the press suction roller (12) is formed by an internally supported hollow roller, preferably a deflection compensation roller. Press arrangement according to claim 22,
characterized by
that the rear counter-roller (24) is formed by an internally supported hollow roller, preferably a deflection compensation roller. Press arrangement according to one of the preceding claims,
characterized by
that the fibrous web (10) following the second extended press nip (S2) is preferably guided to a subsequent dryer section via a deflection roller (30) which is preferably designed as a suction roller. Press arrangement according to claim 24,
characterized by
that the fibrous web (10) is taken over by a wire or felt belt (32) wrapping around the deflecting roller (30) from a felt (18) led out of the second extended press nip (S2).

Images