Capillary drainage device

Abstract

The invention relates to a capillary dewatering device (10) for a machine for the production or finishing of a fibrous web (F), in particular a paper, cardboard or tissue web, comprising a suction roller (14) and a capillary dewatering belt (12) guided over the suction roller (14), wherein the capillary dewatering belt (12) comprises a liquid-permeable carrier layer and a liquid-permeable capillary layer connected to the carrier layer, wherein the capillary layer has pores with a pore size of no more than 15 µm, preferably no more than 10 µm, on a top side facing the fibrous web (F) in the intended operation, and wherein the capillary dewatering belt (10) is guided only over a circumferential section of the suction roller (14).

Description

[0001] The invention relates to a capillary dewatering device for a machine for producing or finishing a fibrous web, in particular a paper, cardboard or tissue web, comprising a suction roll and a capillary dewatering belt guided over the suction roll, wherein the capillary dewatering belt comprises a liquid-permeable carrier layer and a liquid-permeable capillary layer connected to the carrier layer, wherein the capillary layer has pores with a pore size of not more than 15 µm, preferably not more than 10 µm, on an upper side facing the fibrous web during normal operation.

[0002] Such a capillary dewatering device is already known from the document EP 1 300 641 B1. There it is described that a flexible capillary membrane consisting of several layers can be pulled over the outer circumference of a suction roll. The fibrous web to be dewatered is then guided on a carrier fabric over a circumferential section of the rotating suction roll. The fibrous web is clamped sandwich-like between the carrier fabric and the capillary membrane. Through extremely fine pores on the surface of the capillary membrane facing the fibrous web, liquid is extracted from the fibrous web essentially solely by the capillary effect. The liquid in the pores is then drained through the further layers of the capillary membrane into the suction roll with the help of the negative pressure in the suction roll.The advantage of such a capillary dewatering device over a conventional suction roll without a capillary membrane is that a significantly lower vacuum and thus significantly less energy are required to achieve the same increase in dry matter content of the fibrous web. Especially in times of climate change, the issue of energy consumption is playing an increasingly important role in decarbonization.

[0003] However, the capillary dewatering device known from the prior art has several disadvantages. Firstly, the repeated replacement of the capillary membrane due to wear is very time-consuming and expensive. This is especially true if the suction roll is covered with a fine metal or plastic mesh and firmly connected, as has become common practice for such capillary dewatering devices. Typically, the entire suction roll must then be removed and transported away for overhaul. This results in long machine downtimes.

[0004] Secondly, the known capillary dewatering device only functions reliably if the support fabric has a structuring surface, as is the case with the TAD machine described in EP 1 300 641 B1. The term "structuring surface" refers to a surface facing the fibrous web during normal operation that has such large elevations and / or depressions that it imprints a structure on the fibrous web that is easily recognizable to the naked eye. TAD machines are used to produce particularly soft tissue webs, with the abbreviation TAD standing for Through-Air-Drying. To achieve this, the tissue web is deliberately not dewatered in the depressions of the support fabric by pressure, but essentially only by hot air flowing through the fibrous web, which, however, entails high energy requirements.

[0005] Due to the elevations and / or depressions in the support fabric, the tissue web adheres very well to it, so that there is no risk of the tissue web continuing to follow the surface of the suction roll with the capillary membrane instead of remaining on the support fabric when the support fabric is guided away from the peripheral section of the suction roll. The situation is different if the support fabric does not have a structured surface, but rather a relatively smooth one. In this case, the known capillary dewatering device cannot be used reliably without further ado. Due to the limited installation space, it is often not possible to ensure the desired guidance of the tissue web using separating suction devices or the like.

[0006] The object of the present invention is to solve or at least mitigate the aforementioned problems. In particular, it is intended to enable efficient dewatering of a fibrous web that causes minimal machine downtime and / or that functions reliably even when the support fabric for the fibrous web does not have a structuring surface.

[0007] This object is achieved by the features of the independent claims. The dependent claims relate to advantageous developments of the present invention.

[0008] Specifically, the object is achieved according to a first aspect of the present invention by a generic capillary drainage device as described above, which is particularly characterized in that the capillary drainage belt is guided only over a circumferential section of the suction roll. In other words, the capillary drainage belt has a length that is greater than the outer circumference of the suction roll. The capillary drainage belt is therefore not - as in the prior art described above - pulled directly onto the outer surface of the suction roll like a stocking and possibly even undetachably connected to it, but is actually designed as a separate belt that is guided only over a partial section of the outer circumference of the suction roll. This has the advantage that replacement of the capillary drainage belt due to wear can be carried out very quickly, i.e. usually in less than four hours.The suction roll can remain in place and does not have to be removed and moved to another location for overhaul. Secondly, the solution according to the invention has the advantage that the fibrous web can be reliably detached from the capillary dewatering belt, even if the carrier belt on which the fibrous web is guided has a non-structuring surface facing the fibrous web. The separation of the fibrous web from the capillary dewatering belt does not have to take place in the area of ​​the suction roll, but can take place later. This means that, on the one hand, the negative pressure emanating from the suction roll does not counteract the separation, and, on the other hand, there is sufficient space behind the suction roll in the direction of rotation of the capillary dewatering belt to provide guide means to reliably guide the fibrous web, i.e. to hold it on the carrier fabric.

[0009] To ensure reliable circulation of the capillary dewatering belt, the capillary dewatering device can further comprise at least one deflection roller, over which the capillary dewatering belt is also guided. It is particularly advantageous if the capillary dewatering device comprises precisely one deflection roller, the diameter of which is smaller than the diameter of the suction roller. This allows a wrap angle of more than 180° of the capillary dewatering belt around the suction roller to be achieved, so that the portion of the outer circumference of the suction roller contributing to the dewatering of the fibrous web is relatively large.

[0010] Similar to the prior art described at the beginning, the capillary dewatering device can further comprise a support fabric which, during normal use of the capillary dewatering device, supports the fibrous web and sandwiches it between itself and the capillary dewatering belt, while the fibrous web is guided over the circumferential section of the suction roll. Depending on the tension with which the support fabric is guided over the suction roll, it can contribute to pressing liquid out of the fibrous web, which further assists dewatering. The squeezed-out liquid can then be absorbed by the capillary dewatering belt through the capillary effect, or - assisted by the centrifugal forces during deflection - by the radially outer support fabric. The support fabric should preferably be able to temporarily absorb the leaked liquid.In particular, the support covering can be a press felt.

[0011] Even if this is not mandatory, in the present invention, the support fabric can have a surface facing the fibrous web during normal operation that has no structuring effect on the fibrous web. As previously described, it can nevertheless be reliably prevented that the fibrous web follows the capillary dewatering belt instead of the support fabric if the two are separated from each other.

[0012] In order to achieve this reliably, the capillary dewatering device can further comprise guide means which are arranged and designed to guide the fibrous web in the running direction of the capillary dewatering belt behind the suction roll away from the capillary dewatering belt towards the carrier fabric during normal operation.

[0013] The guide means can comprise vacuum means, in particular a vacuum suction device, which is arranged on the side of the support fabric facing away from the fibrous web, wherein the vacuum means preferably act on the run of the capillary dewatering belt, which lies behind the suction roll in the direction of rotation of the capillary dewatering belt, or extends between the suction roll and the at least one deflection roll. The term "run" refers to a part or section of a rotating component exerting tensile force, in this case a section of the capillary dewatering belt. Alternatively or additionally, the guide means can comprise overpressure means, in particular a compressed air nozzle, wherein the overpressure means preferably act in a gap at which the capillary dewatering belt and the support fabric with the fibrous web remaining thereon are separated from one another.

[0014] In an advantageous development of the present invention, the capillary dewatering device can further comprise a press belt, which, during the intended use of the capillary dewatering device, sandwiches the support fabric and the fibrous web carried thereon between itself and the capillary dewatering belt, while the fibrous web is guided over the circumferential section of the suction roll. In this way, moisture can be forced out of the fibrous web and through the support fabric toward the capillary dewatering belt. The press belt is preferably designed to be permeable. Thus, compressive forces, such as the suction forces of a vacuum suction device, can act through it.

[0015] A further aspect of the present invention relates to a capillary drainage belt for a previously described capillary drainage device according to the invention, wherein the carrier layer comprises a carrier fabric, preferably consisting essentially of a carrier fabric. The capillary drainage belt should have a length that is greater than the circumference of a typical suction roll over which the capillary drainage belt is guided during normal operation. Preferably, it is at least twice as long as the circumference of such a suction roll. In particular, the capillary drainage belt can be at least 10 m, preferably at least 12 m long.

[0016] The carrier fabric preferably comprises a first fabric layer, which is essentially formed from first longitudinal threads and first transverse threads woven therewith, and a second fabric layer, which is essentially formed from second longitudinal threads and second transverse threads woven therewith, wherein the first fabric layer is connected to the second fabric layer and faces the capillary layer, wherein the second longitudinal threads and the second transverse threads have a larger diameter than the first longitudinal threads and the first transverse threads. Preferably, the first longitudinal threads and the first transverse threads have essentially the same diameter, and the second longitudinal threads and the second transverse threads have essentially the same diameter. In this way, the through-openings can become increasingly larger in the thickness direction of the capillary dewatering belt, from the outer side facing the fibrous web to the inner side facing away from the fibrous web.The thicker threads on the inside can absorb a large portion of the forces acting on the capillary drainage tape. When referring to thread diameters in this context, for threads that do not have a circular diameter in cross-section, this refers to the diameter that a thread with a circular diameter would have with the same cross-sectional area.

[0017] Furthermore, the carrier fabric can comprise binding threads that connect the first fabric layer to the second fabric layer. The binding threads are preferably always arranged in pairs. This means that two binding threads, both of which extend optionally in the longitudinal or transverse direction of the capillary drainage belt, are arranged directly next to one another in the fabric but follow different weaving paths. Alternatively or additionally, they can have essentially the same diameter as the first longitudinal threads and / or the first transverse threads. This allows them to be easily integrated into the weave pattern of the first fabric layer facing the capillary layer and provide a relatively uniform surface for connecting the capillary layer. For precisely this purpose, it is also advantageous if the first longitudinal threads and the first transverse threads, together with the binding threads, form a plain weave.A plain weave is a very simple and even weave in which each longitudinal thread alternates under and over a transverse thread and vice versa.

[0018] The capillary layer can also be made of a fabric, preferably a fabric made of monofilaments made of a plastic. It is important that the monofilaments and the weave pattern are sufficiently fine to provide correspondingly small pores for the capillary effect.

[0019] The capillary layer can be laminated to the carrier layer. For example, the capillary layer can be bonded to the carrier layer with a fine adhesive layer. However, the adhesive must not clog the fine pores of the capillary layer.

[0020] Furthermore, the present invention relates to a method for dewatering a fibrous web, in particular a paper, cardboard, or tissue web. For this purpose, the fibrous web to be dewatered is guided in a previously described capillary dewatering device according to the invention on a capillary dewatering belt, preferably on a previously described capillary dewatering belt according to the invention, only over a circumferential section of the suction roll and then guided away from the circumferential section of the suction roll on the capillary dewatering belt. The advantages of the present invention described above in connection with the device also apply mutatis mutandis to the method according to the invention, and vice versa.

[0021] An advantageous embodiment of the present invention provides that the circumferential section of the suction roll, over which the fibrous web is guided, is at least 180°.

[0022] To dewater the fibrous web as energy-efficiently as possible, it is advantageous if the suction roll is operated with only as much negative pressure as is necessary to suck the liquid absorbed by the capillary action from the fibrous web into the capillary dewatering belt. In other words, the liquid escaping from the fibrous web should essentially only enter the capillary layer of the capillary dewatering belt through the capillary effect, but not be sucked in by the negative pressure inside the suction roll. The negative pressure of the suction roll only serves to further drain the water from the pores, so that more liquid can be drawn into the pores by the capillary effect.The negative pressure acting through the backing fabric on the back of the capillary membrane must be sufficient to draw the water out of the capillary without interrupting the fluid transport through the capillary. To achieve this effect, a pore size gradient from the machine side of the belt to the paper side of the belt should be correspondingly small.

[0023] Further advantageous embodiments of the invention are explained using exemplary embodiments with reference to the drawings. The features mentioned can be advantageously implemented not only in the illustrated combination, but also individually combined with one another. The figures, which are not to scale, show in detail: Fig. 1 a capillary drainage device according to the present invention; Fig. 2 a three-dimensional view of a capillary drainage belt; Fig. 3 a schematic cross-sectional view of the capillary drainage belt of Fig. 2, and Fig. 4 a modification of the capillary drainage device of Fig. 1.

[0024] The figures are described in more detail below. Fig. Figure 1 shows a capillary dewatering device 10 according to the present invention. The capillary dewatering device 10 comprises a capillary dewatering belt 12, which will be described in more detail later, which is guided over a suction-applied peripheral section of a suction roller 14 and over a deflection roller 16, where it is rotated clockwise in Fig. 1. Together with the capillary dewatering belt 12, a fibrous web F carried by a carrier fabric 18 is guided over the suctioned peripheral section of the suction roll 14, wherein the fibrous web F is sandwiched between the radially outer carrier fabric 18 and the radially inner capillary dewatering belt 12. In Fig. 1, the fibrous web F comes from the left side and leaves the section of the Fig. 1 on the right-hand side, as indicated by arrows. A first guide roller 20 and a second guide roller 22 serve to guide the carrier clothing 18 with the fibrous web F transported thereon. The fibrous web F comes into contact with the capillary dewatering belt 12 at approximately the same point at which the capillary dewatering belt 12 also comes into contact with the suction roller 14. However, the separation of the fibrous web F from the capillary dewatering belt 12 only clearly occurs after the capillary dewatering belt 12 has left the surface of the suction roller 14. This has the advantage that the negative pressure emanating from the suction roller 14 does not hinder the separation of the fibrous web F from the capillary dewatering belt 12.In fact, in this embodiment, the separation only takes place in a gap between the deflection roller 16, over which the capillary dewatering belt 16 is guided, and the second guide roller 22, over which the carrier fabric 18, which carries the fibrous web F, is guided.

[0025] To make the separation of the fibrous web F from the capillary dewatering belt 12 even more reliable, even in cases where the support fabric 18 does not have a structuring surface facing the fibrous web F, but rather a relatively smooth surface, such as the surface of a flow layer, as is commonly found in press felts, the capillary dewatering device 12 according to the invention can also have guide means. In particular, a vacuum suction device 24 can act on the support fabric 18 from the side facing away from the fibrous web F, shortly after it has left the vacuumed peripheral section of the suction roll 14. As a result, the fibrous web F is pulled away from the capillary dewatering belt 12 toward the support fabric 18.Alternatively or additionally, the capillary dewatering device 10 can also comprise a compressed air nozzle 26 as a guide means, which can blow a compressed air jet into the gap in which the carrier fabric 18 with the fibrous web F is to be separated from the capillary dewatering belt 12. Furthermore, alternatively or additionally, the second guide roller 22 can also be vacuumed in sections to hold the fibrous web F on the carrier fabric 18.

[0026] Since the diameter of the single deflection roller 16 over which the capillary dewatering belt 12 is guided is significantly smaller than the diameter of the suction roller 14, the wrap angle of the capillary dewatering belt 12 around the suction roller 14 is greater than 180°. The capillary dewatering belt 12 has a length that is significantly greater than the circumference of the suction roller 14, preferably at least twice as long. This provides sufficient installation space, for example, to be able to position the vacuum suction device 24 along the run of the capillary dewatering belt 12 between the suction roller 14 and the deflection roller 16.

[0027] If the capillary drainage belt 12 becomes worn at some point, it can be removed and replaced relatively easily in the capillary drainage device 10 according to the invention. Removal and overhaul of the suction roll are not necessary.

[0028] In particular along the run of the capillary dewatering belt 12, which extends from the deflection roller 16 to the suction roller 14, conditioning means (not shown here) can also be provided if required in order to condition the capillary dewatering belt 12, in particular to clean it and / or to moisten it in a targeted manner.

[0029] The Fig. 2 and Fig. 3 schematically show an exemplary embodiment of a capillary dewatering belt 12 according to the present invention. The capillary dewatering belt 12 comprises a capillary layer 28 facing the fibrous web F during normal operation, said capillary layer having very fine pores, in particular pores with a pore size of no more than 15 µm, preferably no more than 10 µm. Here, too, the pore size refers to the diameter and a circular cross-sectional shape. Should the pores not actually have a circular cross-sectional shape, a pore with a circular cross-sectional shape and the same cross-sectional area should be assumed.

[0030] Furthermore, the capillary dewatering belt 12 comprises a carrier fabric 30, which, during normal operation, faces away from the fibrous web and is connected to the capillary layer 28. In particular, the capillary layer 28 can be laminated to the carrier fabric 30 with a thin adhesive layer.

[0031] As in Fig. 3, the carrier fabric 30 comprises a first fabric layer L1 and a second fabric layer L2. The first fabric layer L1 is formed from first longitudinal threads LF1 and first transverse threads QF1, which are woven together in the form of a plain weave. The second fabric layer L2, in contrast, is formed from second longitudinal threads LF2 and second transverse threads QF2 woven therewith, wherein the second longitudinal threads LF2 and the second transverse threads QF2 have a diameter that is noticeably larger than the diameter of the first longitudinal threads LF1 and the first transverse threads QF1. The first fabric layer L1 is preferably connected to the second fabric layer L2 by binding threads (not shown here), wherein the binding threads can always occur in pairs and / or can have substantially the same cross-section as the first longitudinal threads LF1 and the first transverse threads QF1 and / or together with the first longitudinal threads LF1 and the first transverse threads QF1 complete a plain weave of the first fabric layer L1.Preferably, all of these apply. Fabrics such as the carrier fabric 30 here are known from the field of forming fabrics, e.g., as so-called SSB fabrics. SSB stands for Shute Support Binder, where the binding threads in the flat-woven fabric are the weft threads in the weaving process. They are relatively readily available on the market and have surprisingly proven to be suitable carrier fabrics 30 for supporting the capillary layer 28. The capillary layer 28 itself can be a fabric made of extremely fine threads.

[0032] The first fabric layer L1 is arranged between the capillary layer 28 and the second fabric layer L2. This creates increasingly larger openings in the thickness direction T of the capillary dewatering belt 12 for the liquid that is drained from the fibrous web F contacting the capillary layer 28 during normal operation by the capillary dewatering belt 12. The fine pores of the capillary layer 28 absorb the liquid essentially only through capillary forces. However, the tension with which the carrier fabric 18 is guided around the suction roller 14 can also promote the dewatering of the fibrous web. The suction emanating from the suction roller 14 draws the liquid from the pores through the carrier fabric 30, so that new liquid from the fibrous web F can flow into the pores through the capillary effect. This type of dewatering is very energy-efficient.

[0033] Fig. 4 shows a modification 10' of the capillary drainage device 10 of Fig. 1. In this case, Fig. 4 the same reference numerals refer to the same components or component sections as in Fig. 1, to the description of which reference is hereby made. In contrast to the first embodiment according to Fig. 1, the second guide roller 22' is modified in such a way that it is suctioned in sections in order to securely hold the fibrous web F on the carrier fabric 18. Furthermore, the capillary dewatering device 10' according to Fig.4 also includes a permeable press belt 36, which is guided over the first guide roller 20, the modified second guide roller 22', a third guide roller 32, and a fourth guide roller 34. The press belt 36 sandwiches the support fabric 18 and the fibrous web F carried thereon between itself and the capillary dewatering belt 12, while the fibrous web F is guided over the circumferential section of the suction roller 14. This allows pressure to be applied to the fibrous web F, which forces moisture out of the fibrous web F and through the support fabric 18 to the suction roller 14, further increasing the efficiency of the capillary dewatering device 10' according to the invention. List of reference symbols 10, 10' capillary drainage device 12 capillary drainage tape 14 suction roller 16 Deflection roller 18 support covering 20 first guide roller 22, 22' second guide roller 24 vacuum suction cups 26 Compressed air nozzle 28 Capillary layer 30 carrier fabrics 32 third guide roller 34 fourth guide roller 36 Press belt D Thickness direction F Fibrous web L1 first tissue layer L2 second fabric layer Q1 first cross threads Q2 second cross threads QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 1 300 641 B1 [0002, 0004]

Claims

[1] Capillary dewatering device (10, 10') for a machine for producing or finishing a fibrous web (F), in particular a paper, cardboard or tissue web, comprising a suction roll (14) and a capillary dewatering belt (12) guided over the suction roll (14), wherein the capillary dewatering belt (12) comprises a liquid-permeable carrier layer and a liquid-permeable capillary layer (28) connected to the carrier layer, wherein the capillary layer (28) has pores with a pore size of not more than 15 µm, preferably not more than 10 µm, on an upper side facing the fibrous web (F) during normal operation, characterized by that the capillary dewatering belt (10,10') is guided only over a circumferential section of the suction roller (14). [2] Capillary drainage device (10, 10') according to claim 1, characterized bythat the capillary drainage device (10, 10') further comprises at least one deflection roller (16) over which the capillary drainage belt (12) is also guided, wherein the capillary drainage device (10, 10') preferably comprises exactly one deflection roller (16) whose diameter is smaller than the diameter of the suction roller (14). [3] Capillary drainage device (10, 10') according to claim 1 or 2, characterized by that the capillary dewatering device (10, 10') further comprises a support fabric (18) which, during the intended use of the capillary dewatering device (10, 10'), supports the fibrous web (F) and sandwiches it between itself and the capillary dewatering belt (12), while the fibrous web (F) is guided over the circumferential section of the suction roll (14). [4] Capillary drainage device (10, 10') according to claim 3, characterized bythat the carrier covering (18) has a surface facing the fibrous web (F) during normal operation, which surface has no structuring effect on the fibrous web (F), wherein the carrier covering (18) is preferably a press felt. [5] Capillary drainage device (10, 10') according to claim 3 or 4, characterized by that the capillary dewatering device (10, 10') further comprises guide means which are arranged and designed to guide the fibrous web (F) in the running direction of the capillary dewatering belt (12) behind the suction roller (14) away from the capillary dewatering belt (12) towards the carrier fabric (18) during normal operation. [6] Capillary drainage device (10, 10') according to claim 5, characterized byin that the guide means comprise negative pressure means, in particular a vacuum suction device (24), which are arranged on the side of the carrier clothing (18) facing away from the fibrous web (F), wherein the negative pressure means preferably act on the run of the capillary dewatering belt (12) which lies behind the suction roller (14) in the direction of rotation of the capillary dewatering belt (12), and / or in that the guide means comprise positive pressure means, in particular a compressed air nozzle (26), wherein the positive pressure means preferably act in a gap at which the capillary dewatering belt (12) and the carrier clothing (18) with the fibrous web (F) remaining thereon are separated from one another. [7] Capillary drainage device (10, 10') according to one of claims 3 to 6, characterized bythat the capillary dewatering device (10, 10') further comprises a press belt (36) which, when the capillary dewatering device (10, 10') is used as intended, sandwiches the support fabric (18) and the fibrous web (F) carried thereon between itself and the capillary dewatering belt (12), while the fibrous web (F) is guided over the circumferential section of the suction roll (14), the press belt (36) preferably being designed to be permeable. [8] Capillary drainage belt (12) for a capillary drainage device (10, 10') according to one of the preceding claims, characterized by that the carrier layer comprises a carrier fabric (30), preferably consists essentially of a carrier fabric (30). [9] Capillary drainage belt (12) according to claim 8, characterized byin that the carrier fabric (30) comprises a first fabric layer (L1) which is essentially formed from first longitudinal threads (LF1) and first transverse threads (QF1) woven therewith, and a second fabric layer (L2) which is essentially formed from second longitudinal threads (LF2) and second transverse threads (QF2) woven therewith, wherein the first fabric layer (L1) is connected to the second fabric layer (L2) and faces the capillary layer (28), wherein the second longitudinal threads (LF2) and the second transverse threads (QF2) have a larger diameter than the first longitudinal threads (LF1) and the first transverse threads (QF1). [10] Capillary drainage belt (12) according to claim 9, characterized byin that the carrier fabric (30) further comprises binding threads which connect the first fabric layer (L1) to the second fabric layer (L2), wherein the binding threads are preferably always arranged in pairs and / or have substantially the same diameter as the first longitudinal threads (LF1) and / or the first transverse threads (QF1) and / or the first longitudinal threads (LF1) and the first transverse threads (QF1) together with the binding threads form a plain weave. [11] Capillary drainage belt (12) according to one of claims 8 to 10, characterized by that the capillary layer (28) is formed from a fabric, preferably from a fabric of monofilaments consisting of a plastic. [12] Capillary drainage belt (12) according to one of claims 8 to 11, characterized by that the capillary layer (28) is laminated to the carrier layer. [13] Method for dewatering a fibrous web (F), in particular a paper, cardboard or tissue web, wherein for this purpose the fibrous web (F) to be dewatered is guided in a capillary dewatering device (10, 10') according to one of claims 1 to 7 on a capillary dewatering belt (12), preferably according to one of claims 8 to 12, only over a circumferential section of the suction roll (14) and is then guided away from the circumferential section of the suction roll (14) on the capillary dewatering belt (12). [14] Method according to claim 13, characterized by that the circumferential section of the suction roll (14) over which the fibrous web (F) is guided is at least 180°. [15] Method according to claim 13 or 14, characterized bythat the suction roller (14) is operated essentially only with as much negative pressure as is necessary to suck the liquid absorbed by the capillary action from the fibrous web (F) into the capillary dewatering belt (12) out of the capillary dewatering belt (12).

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