DE19921202A1 - Press assembly for water extraction from a wet fiber web - Google Patents

Abstract

The press section of a machine processing a wet fiber web has a lower shoe press roller (20) and two upper shoe press rollers (22,24) to form two extended press gaps (S1,S2) along the line (L) of web (10) travel. Two blankets pass through the first press gap (S1). The second press gap (S2), in the direction (L) of web travel, has a single blanket moving through it, with the web (10) between the blanket (18) and the upper press roller (24) at the second press gap (S2). The second press gap (S2) can have two blankets passed through it, and the press assembly uses a max. of three blankets (14,18,26). The press section has a closed web guide path. One blanket (18) passes through both press gaps (S1,S2), with the web (10), and together round a suction deflection roller (36) between the gaps. The first blanket (14) through the press gaps (S1,S2) also acts as a pick-up blanket, moving with the web (10) on a rising inclined path into the first press gap (S1). The web (10), on leaving the second press gap (S2), is deflected round a suction roller (30) to move onwards pref. to a following drying station. On arrival at the second press gap (S2), the web (10) is passed to a blanket (18) which carries it through, and the web (10) is detached from the blanket (18) at the suction deflection roller (30), while the blanket (18) follows a downward path away from the web. The web (10) can follow a free and unsupported path between the second press gap (S2) and the suction deflection roller (30). The flexible shoe press roller mantle has blind drillings and/or ridges at the rollers (20,22,24) forming the press gaps (S1,S2). The trailing upper press roller (24) can have a smooth roller mantle, where a single blanket carries the web through the second press gap (S2). The water extraction action at least at one press gap (S1,S2) is at least partially through centrifugal forces, where the water is spun out to be caught in a gutter (72,74,76,78) or the like. At least one of the upper press rollers (22,24) is a hollow roller, with internal supports, pref. as a bending compensation roller, and at least one of the upper rollers (22,24) is solid. A blowing tube is at the trailing upper press roller (24), at least over the whole web width. A suction unit (66) is at the second press gap (S2), in the outlet gap between the roller and the web/blanket, to catch water spray and/or extract water from the web (10) and the lower blanket (18) emerging from the press gap (S2). A suction roller to separate the web is after the second press gap (S2). The shoe press roller (20) has a press mantle guide to give position stability. The press roller (20) has two supports for the roller press mantle at the press gaps (S1,S2), on an inner support carrier, with the press shoes linked to the supports. The support force can be varied, independently for each support. The non-rotating hollow carrier and the inner carrier are in equidistant mountings at their ends. The amount of bend can be adjusted at the inner carrier of the press roller, to compensate for the forces applied at the two press gaps (S1,S2). The bending action is affected by the use of heat on the inner carrier, or the carrier has slits to give a controlled bending action or it has an inner or outer auxiliary carrier to give a bend through radial clamping using a hydraulic, pneumatic, mechanical, thermal and/or electromagnetic system. The bend at the inner carrier can also be set by a row of supports between the hollow and inner carriers, across the direction of web travel. The press mantle is offset from the hollow carrier, as seen on the cross section plane of the roller (20), and it is polygonal at least in sections. The upper press rollers (22,24) each have a support, to press them against the supports of the center press roller (20) at an equal pressure for the two press gaps (S1,S2), each with separate and independent pressures. On leaving the second press gap (S2), the blanket (18) is deflected by a pref. swing guide roller (96), and the blanket (14) leaving the first press gap (S1) is deflected by a pref. swing guide roller (97). The upper press rollers (22,24) are powered, where the second roller (24) has a higher drive power than the leading roller (22),

Description

The invention relates to a device for treating a material web, in particular a paper or cardboard web in which the Ma material web together with a porous support band over a particular right as a pick-up and / or transfer roller, a perforated jacket having suction roll is guided, the porous support belt in the loading range of the suction roll lies between this and the material web.

In the previously common devices of the type mentioned in Connection to the pick-up or transfer suction roller is usually a ge Separately operated web suction box or pipe suction provided. This is associated with a correspondingly high expenditure of energy. It has to be on the desired vacuum is generated at different points, what usually separate blowers are used for. It also results a large space requirement. So are in addition to the larger installation cross section more piping required. It doesn't just have to be an additional one Blowers are used, there is also an additional Verroh expenditure.

The aim of the invention is to provide a device of the type mentioned create the ins with a simple and compact structure in particular can also be operated with a significantly lower energy expenditure is.  

This object is achieved according to the invention in that the suction roller both in the run-up area and in the run-off area of the material web because it is adjacent to the inside of the perforated roll shell Suction zone has that the suction zone provided in the run-up area with a vacuum source is connected, that one after the expiration richly arranged outer web holding box or pipe vacuum over the in Drainage area provided suction is suctioned and that this Web holding box or the pipe suction, in the drain area provided suction zone over the provided in the run-up area, with the Vacuum source connected suction zone is subjected to vacuum.

This training results in an energy-saving and com pacts, by combining a suction roller with a web stop Most functional or pipe suction unit received, with which in the An close to the suction roller in an optimal way a closed web guide tion can be realized. Due to the vacuum of the suction whale carried along ze is not only vacuumed the web holding box or the pipe vacuum, the This vacuum is also used to avoid bubbles dung before the subsequent nip, so that at the same time a correspond appropriate stabilizer effect is achieved. So is especially under aid taking the continuously produced evacuated perforated air at the end of the suction zone for further web adhesion on the porous support band.

At the same time, noise insulation is achieved on the suction roller. All in everything results in a cost-effective overall solution.

In a single-screen dryer group described in DE 40 23 297 A1 a screen deflecting roller is provided between two drying cylinders following an extensive coherent suction zone  further suction zone arranged in the discharge area of the material web points that executed without connection to the inside of the suction box or connected to the inside of this suction box by means of throttle ducts can be. This screen deflection roller is neither a web holding box nor assigned a pipe suction.

In an expedient practical embodiment of the erindungsge moderate device is in the web running direction between that in Aufaufbe rich and the suction zone provided in the discharge area of the material web at least one intermediate suction zone is provided. It is both the Zwi suction zone as well as the suction zone provided in the drain area the one provided in the run-up area and connected to the vacuum source Vacuum applied to the suction zone.

The intermediate suction zone and / or those in the drainage zone are advantageous richly provided suction zone at least in part by the particular Vacuum of the suction roller dragged along via the evacuated jacket holes vacuumed.

In an expedient practical embodiment, the are in the Suction zone provided and the following in the web running direction connecting suction zone via at least one throttle point the.

The porous support band can in particular be formed by a felt.  

In a preferred practical embodiment of the invention ß device, the web of material is featured by the in the run-up area see suction zone of the suction roll removed from a felt.

The suction roll can, for example, be provided between two presses his.

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

The invention is un based on exemplary embodiments ter explained in more detail with reference to the drawing; in this show:

Fig. 1 is a schematic, partially sectioned illustration of a transfer suction roll with associated web stops and

Fig. 2 is a schematic, partially sectioned illustration of a press arrangement with two shoe presses, between which the one transfer suction roller and a web holding box comprising functional unit according to FIG. 1 is used.

Fig. 1 shows a schematic, partially sectioned view of a transfer-suction roll 10 with associated web holding box 12. The functional unit formed thereby is part of a device for treating a material web 14 , which can in particular be a paper or cardboard web.

The material web 14 is guided together with a porous support belt, here a felt 16 , via which the transfer suction roller 10 is also used in particular as a pick-up roller.

Within the perforated jacket 18 of the transfer suction roller 10 , a sta tionary suction box 20 is arranged, the interior of which is connected to a vacuum source, which may include a blower 22 , for example.

The transfer suction roller 10 has both in the run-up area A and in the discharge area B of the material web 14 or the felt 16 lying between the latter and the transfer suction roller 10 , a suction zone 24 or 26 adjacent to the inside of the perforated roller shell 18 , between which a further suction zone 28 can be provided.

The suction zones 24 , 26 , 28 are in the inner circumferential direction of the transfer suction roller 10 each by de parallel to the roller axis 30 , de, between the stationary suction box 20 and the inside of the roller zenmantels 18 arranged sealing strips 32 to 38 limited. The suction zones 24 , 26 , 28 are each designed as suction chambers open towards the inside of the perforated roller shell 18 .

The arranged in the outlet area B outer web holding box 12 is sucked through the suction zone 26 provided in the outlet area B.

Of the three suction zones 24 , 26 , 28 , only the suction zone 24 provided in the run-up area A is directly connected to the inside of the stationary suction box 20 and thus the vacuum source 22 . The intermediate suction zone 28 and the suction zone 26 provided in the outlet area B of the material web 14 are thus subjected to vacuum via the suction zone 24 provided in the opening area A and connected to the vacuum source 22 . In this case, the suction zones 28 and 26 arranged behind the suction zone 24 in the web running direction L are at least partially acted upon by the vacuum which is entrained in particular via the evacuated jacket holes 40 of the roller jacket 18 .

The entire vacuum is thus primarily directly connected to the suction zone 24 provided in the area Auflaufbe. The suction zone 24 provided in the run-up area A and the intermediate suction zone 28 which follows in the web running direction L can, however, be connected to one another via a throttle point 42 , which is formed in the present case by leaving a corresponding gap between the axial sealing strip 34 in question and the roller jacket 18 . A variable throttle point can be provided, for example. In principle, it is also possible to provide a preferably variable connection between the suction zone 26 provided in the discharge area B and the water preceding the intermediate suction zone 28 . Several such throttle positions can also be provided.

In the present case, the material web 14 is removed by the suction zone 24 of the transfer suction roller 10 provided in the run-up area A from a felt 44 , which is previously guided around a roller 46 , which can be assigned to a press, for example. The intermediate suction zone 28 serves to hold the material web 14 removed from the felt 44 on the felt 16 guided over the transfer suction roller 10 .

The entire vacuum generated by the vacuum source 22 is thus primarily connected directly to the suction zone 24 provided in the run-up area A.

After the material web 14 has been taken over by the transfer suction roller 10 in the area of the suction zone 24 , the permeability of the felt 16 above the suction zone 24 is suddenly reduced, as a result of which an active vacuum is built up in the intermediate suction zone 28 . The intermediate suction zone 28 and the suction zone 26 provided in the drainage area B can be opened at least in part by the vacuum entrained in particular via the evacuated jacket holes 14 with a corresponding vacuum. Of particular importance here is the air permeability of the felt 16 and the material web 14 .

In the present case, the two suction zones 24 and 28 are also connected to one another via the throttle point 42 . This throttle point 42 can in particular also be variable. In principle, another throttled or throttled connection between the two suction zones 24 and 28 can also be provided. In principle, it is also possible to provide at least one preferably again variable, in particular throttled connection between the suction zone 26 provided in the drainage area B and the intermediate suction zone 28 preceding this.

The suction zone 26 provided in the drainage area B, which in the present case does not begin until after this drainage area B, is used for the vacuum which is dragged along in particular via the evacuated jacket holes 40 and is released after the third sealing strip 36 in order to generate the required vacuum inside take advantage of the web stop box 12 , so that a separate suction of this web stop box 12 is no longer necessary. The fourth sealing strip 38 must be provided for this. The additional chamber-like suction zone 26 formed by this, together with the almost closed interior 48 of the web holding box 12, simultaneously acts as a noise insulation chamber. In principle, the suction zone 26 can also begin before the discharge area B. It then extends correspondingly far beyond the drain area B to act upon the web holding box 12 .

The web holding box 12 is trough-shaped and open to the transfer suction roll 10 , the opening area in question by a seal 50 such. B. a scraper with compressed air is limited to the area of the associated suction zone 26 of the transfer suction roller 10 .

The area between the web holding box 12 and the felt 16 carrying the material web 14 is sealed at the rear end in the web running direction L of the web holding box 12 by a seal 52 , which can be, for example, a non-contact seal or a lip seal. A non-contact seal can be implemented, for example, in the manner of an air sword by blowing air obliquely against the felt. As a lip seal, for example, a plastic flap clinging to the felt 16 is conceivable.

On the end faces, the interior 48 of the web holding box 12 can be sealed, in particular without contact, by sealing plates with a small gap to the felt 16 or to the transfer suction roll 10 , or alternatively, for example, with an air sword.

The negative pressure which arises in the web holding box 12 can be adjustable for example via a vacuum breaker, in particular a vacuum throttle or the like.

The web holding box 12 can be provided in its lower region with a dirty water drain 54 , which can be assigned, for example, a drain line or a drain hose, which m or det at a deeper location in a water castle or a siphon, so that the in the interior 48 of the web holding box 12 setting negative pressure is maintained. If the interior 48 of the Bahnhalteka least 12 is connected to a vacuum breaker such as, in particular, a vacuum throttle or the like, this vacuum can be set as desired.

According to Fig. 1, supported by the felt 16 Material web 14 is finally fed to a roller 56 wrapped by a felt 64 and, for example, a press can be zugeord net again as well as the roller 46.

Fig. 2 shows a schematic, partially sectioned view of a press arrangement with two shoe presses, between which the transfer-suction roll 10 and the web holding box 12 is inserted comprehensive functi onseinheit of FIG. 1.

In this press arrangement, the material web 14 in the area of a suction roll 58 is taken over by an upper felt 60 from a wire belt 62 and then fed together with a lower felt 16 to a first press nip S1 extended in the web running direction L. Subsequently, the material web 14 is fed together with the bottom felt 16 via the transfer suction roll 10 and then to a second press nip S2 extended in the web running direction L.

As can be seen in FIG. 2, the two press nips S1 and S2, which are elongated in the web running direction L, are formed by two separate shoe presses, one adjacent to the other, each from a shoe press unit 66 and 68 located at the bottom and a counter roller 46 and 56 located at the top.

Following the second extended in the web running direction L nip S2 the web is preferably passed over an extended as a suction roll formed guide roller 70 14 and in the range of another as a suction roller designed deflection roller 72 of a dryer fabric 38 taken over and the first drying cylinder 76 of a dryer section supplied leads.

After the material web 14 , following the first extended press nip S1, is guided together with the bottom felt 16 around the transfer suction roller 10 and then a little along the web holding box 12 , in the area of which it is sucked through the felt 16 , a continuously closed web guide results , namely from the takeover of the material web 14 by the upper felt 60, which also serves as a pick-up felt, from the sieve belt 62 to the transfer to the drying section.

Around the counter roller 56 of the second shoe press 56 , 68 , an upper felt 64 is guided so that both shoe presses 46 , 66 and 56 , 68 are each felted twice. Following the second extended press nip S2, the material web 14 is again separated from the upper felt 64 in the region of the deflection roller 70 designed as a suction roller.

As can be seen from FIG. 2, the web holding box 12 is arranged after the transfer suction roller 10 and between this and the Ge genwalze 56 of the following shoe press 56 , 68 .

In the present case, a press arrangement with two shoe press units 66 and 68 located at the bottom, the material web 14 is thus guided together with the underfelt 16 guided by the two shoe presses via the transfer suction roll 10 and the web holding box 12 .

However, such press arrangements are also conceivable, for example, which result from the fact that the press arrangement described above is mirrored about the vertical and / or the horizontal axis. In the horizontally mirrored variant would then be a top felt (pick-up felt) Tandem felt are passed through both press nips.  

Reference list

10th

Transfer suction roller

12th

Web stop box

14

Material web

16

porous support tape, felt

18th

perforated roller jacket

20th

Suction box

22

Vacuum source, blower

24th

Suction zone in the run-up area

26

Suction zone in the drain area

28

Intermediate suction zone

30th

Roller axis

32

Sealing strip

34

Sealing strip

36

Sealing strip

38

Sealing strip

40

Jacket holes

42

Throttling point

44

felt

46

roller

48

inner space

50

poetry

52

poetry

54

Waste water drain

56

roller

58

Suction roll

60

Top felt

62

Screen belt

64

Top felt

66

Shoe press unit

68

Shoe press unit

70

Deflection roller

72

Deflection roller

74

Dryer fabric

76

Drying cylinder
A run-up area
B drain area
L web running direction
S1 extended press nip
S2 extended press nip

Claims (16)

1. Apparatus for treating a material web ( 14 ) such as in particular a paper or cardboard web in which the material web ( 14 ) is used together with a porous support belt ( 16 ), in particular as a pick-up and / or transfer roller, one perforated jacket ( 18 ) having suction roll ( 10 ) is guided, the porö se support belt ( 16 ) in the area of the suction roll ( 10 ) between this and the material web ( 14 ), characterized in that the suction roll ( 10 ) both in the run-up area (a) and in the exit region (B) of the web (14) each one on the inside of the perforated roll shell side (18) adjoining the suction zone (24 or 26), that provided in the baking area (a) the suction zone (24) is connected to a vacuum source ( 22 ) that an outer Bahnhal tekasten ( 12 ) or pipe suction device arranged in connection with the outlet area (B) is suctioned via the suction zone ( 26 ) provided in the outlet area (B) and that the B ahnhalteka most ( 12 ) or the vacuum cleaner acting in the drainage area (B) provided suction zone ( 26 ) on the provided in the run-up area (A) provided with the vacuum source ( 22 ) connected suction zone ( 24 ) is subjected to vacuum. 2. Device according to claim 1, characterized in that in the web running direction (L) between the in the run-up area (A) and in the run-off area (B) of the material web ( 14 ) provided suction zone ( 24 or 26 ) at least one intermediate suction zone ( 28 is hen) vorgese and that both the Zwischensaugzone (28) also applied as provided for in the exit region (B) the suction zone (26) provided on the rich in Auflaufbe (A), connected to the vacuum source (22) the suction zone (24) with vacuum is. 3. Apparatus according to claim 1 or 2, characterized in that the intermediate suction zone ( 28 ) and / or the suction zone ( 26 ) provided in the outlet region (B) at least partly by the vacuum entrained by the evacuated jacket holes ( 40 ) of the suction roller ( 10 ) are subjected to a vacuum. 4. Device according to one of the preceding claims, characterized in that the suction zone ( 24 ) provided in the run-up area (A) and the suction zone ( 28 ) following in the web running direction (L) are connected to one another via at least one preferably variable throttle point ( 42 ). 5. Device according to one of the preceding claims, characterized in that at least a preferably variable throttled connection is provided at least between the suction zone ( 26 ) provided in the outlet region (B) and the suction zone ( 28 ) preceding this. 6. Device according to one of the preceding claims, characterized in that the suction zones ( 24 , 26 , 28 ) are each designed as suction chambers open to the inside of the perforated roller shell ( 18 ). 7. Device according to one of the preceding claims, characterized in that the suction zones ( 24 , 26 , 28 ) in the inner circumferential direction of the suction roller ( 10 ) each by parallel to the roller axis ( 30 ) erstrec kende, between a stationary suction box ( 20 ) and the inside of the roll shell ( 18 ) arranged sealing strips ( 32 , 34 , 36 , 38 ) are limited. 8. The device according to claim 7, characterized in that to form a provided in the run-up area (A) suction zone ( 24 ) with the subsequent in the web running direction (L) suction zone ( 28 ) connecting throttle point ( 42 ) between the relevant axial sealing strip ( 34 ) and the roll shell ( 18 ) is left a gap sen. 9. Device according to one of the preceding claims, characterized in that the web holding box ( 12 ) is trough-shaped. 10. Device according to one of the preceding claims, characterized in that the web holding box ( 12 ) to the suction roll ( 10 ) open and the opening area in question by a corresponding seal ( 50 ) at least substantially on the area of the relevant suction zone ( 26 ) of the suction roll ( 10 ) is limited. 11. Device according to one of the preceding claims, characterized in that the region between the web holding box ( 12 ) and the porous support band ( 16 ) carrying the material web ( 14 ) at the rear end of the web holding box ( 12 ) in the web running direction (L) preferably before is sealed by a non-contact seal ( 52 ) or a lip seal. 12. Device according to one of the preceding claims, characterized in that the negative pressure in the web holding box ( 12 ) is preferably adjustable via a vacuum breaker such as in particular a Va vacuum throttle valve or the like. 13. Device according to one of the preceding claims, characterized in that the web holding box ( 12 ) is provided in its lower region with a dirty water drain ( 54 ), which is preferably associated with a drain line, which opens at a lower point in a water castle. 14. Device according to one of the preceding claims, characterized in that the porous support band is formed by a felt ( 16 ). 15. Device according to one of the preceding claims, characterized in that the material web ( 14 ) is removed by a felt ( 44 ) through the suction zone of the suction roller ( 10 ) provided in the run-up area (A). 16. Device according to one of the preceding claims, characterized in that the suction roller ( 10 ) between two presses ( 46 , 66 ; 56 , 68 ) is seen before.