EP2072674A2 - Method for the web-wide transfer of a fibre material web into a machine to manufacture fibre material webs and machine to manufacture a fibre material web - Google Patents

Abstract

The method involves temporarily increasing moisture content of a fiber material web (F) and/or lining (T2) protecting the fiber material web, in a portion of transfer area between a forming device and a drying device (6). The moisture content of the fiber material web and/or the lining is increased over a predefined time period, where the increase takes place during a start or after a fiber material web tear until the fiber material web reach the contact drying device. An independent claim is also included for a method for manufacturing a fiber material web.

Description

The invention relates to a method for the web-width transfer of fibrous webs in a machine for producing a fibrous web, in particular paper, cardboard or tissue web, between a forming device and a device for contact drying a drying device over a drying section free from contact drying, in particular at least one impingement -Trockeneinrichtung.

Machines for the production of fibrous webs, in particular in the form of paper, cardboard or tissue webs are known in a variety of embodiments of the prior art. These comprise a wet part and an adjoining dry part, wherein the wet part consists essentially of a forming device and a downstream of this press device. In the forming device, sheet formation takes place by dewatering a pulp suspension, the dry content of the fibrous web formed in the forming device being increased in the downstream press device. The drying device, which adjoins the press device, serves to further increase the dry content of the fibrous web. There are different versions of drying devices known. As a rule, the drying takes place by a contact drying method, in particular by guiding the fibrous web over drying cylinders.

In embodiments with closed, in particular always supported by string web run in the press section, however, the possible operating speed of the machine for producing fibrous webs is limited by the strength of the fibrous web. To increase this strength, you can increase the dry content before the first drying cylinder by immediately after the press of the actual contact drying a Hot air drying in the form of impingement drying upstream. The web guide via such a hot air dryer can be substantially straight, with a small curvature or supported on a roller. The principle of hot-air drying is based on the fact that the fibrous web supported on an air-permeable belt, in particular a wire belt, is exposed to the hot-air dryer on the surface facing away from the screen belt. The web guide is preferably between the press device and the drying device, in particular the hot air dryer free of a free train. For this purpose, the fibrous web can be supported by a press felt or a transfer belt, which serves to take over the fibrous web to a drying wire. In general, a plurality of such impingement drying devices are arranged one behind the other, wherein these can be designed differently in terms of design and arrangement. In particular, the arrangement of these and the fibrous web guiding direction resulting therefrom can vary. The individual hot-air drying devices can be assigned to different sides of the fibrous web. In order to transfer the web after a demolition in the wet part or when starting the machine, a Abnahmesaugwalze is dipped in the forming fabric web width and passed the web through the press device and an impingement drying device through the machine to the first drying cylinder. From the first drying cylinder, a strip can then be produced by separating it from the web to form a residual web that can be converted into the pulper and transferring it over the entire drying section. If this strip is stable, it is widened to the complete web width until the entire web is transferred in the area of contact drying. A major problem with a desired web-wide transfer is that the web must always be carried along with the Trockensiebbändern and not lift off. If the suction roll used for web removal between press device and impingement drying device is unable to remove the web correctly, it accumulates between the drying wire and the hot air dryer. The result is a demolition of the Bahnüberführvorganges and a loss of production. With very strong accumulation damage on the dry sieve belt can occur up to the Trockensiebriss.

This problem is further exacerbated with increasing length of the intended impingement drying section, since the fabric supporting the fibrous web is guided in this area via at least two guide rollers which are arranged at a distance from one another in the direction of passage of the fibrous web and form narrow support areas. An additional arrangement of suction boxes on the inside of the fabric between the support areas does not lead to the desired stabilization of the position of the fibrous web on the fabric in the transfer. Once the fibrous web is transferred, the boxes are necessary.

From the publication DE 10 2004 053 476 A1 a device and a method for transferring a fibrous web or a transfer strip from a belt of a drying unit of a machine for producing and / or finishing the fibrous web is previously known, wherein on the contact surface of the belt before contact with the fibrous web or the transfer strip of a coating unit a adhesion agent is applied between the fibrous web and the tape, which acts as an adhesion agent. This order is carried out continuously or discontinuously during a certain period of time, preferably during the transfer process. As an adhesive, preferably water is used. The bands are drying fabrics by means of which the fibrous web is guided around a support roll which can be acted upon by means of a blast hood.

The invention is therefore based on the object, a method for web-wide transfer of a fibrous web between two units of a machine for producing fibrous webs, in particular between a former and a dryer section such that the disadvantages mentioned are avoided and a web-wide transferring between the former and the Drying section with stable web guide is possible.

The solution according to the invention is characterized by the features of claims 1 and 26, 38. Advantageous embodiments are described in the subclaims.

The inventive method for transferring fibrous webs in a machine for producing a fibrous web, in particular paper, cardboard, or tissue web, between a forming device and a device for contact drying a drying device over a drying section free of contact drying, in particular via at least one impingement drying device is characterized in that in at least a portion of the transfer region between the forming device and means for contact drying, preferably before the impingement drying at least temporarily increases the moisture content of the fibrous web and / or fabric.

By increasing the moisture content of the fibrous web and / or the fabric supporting it, an adhesion effect due to adhesion between the fibrous web and the supporting fabric supporting it is given in the area of the impingement drying device. This at least temporary adhesive effect serves for the safe and stable transfer of the fibrous web, in particular during startup or after a fibrous web break when passing through the impingement drying device.

Impingement drying device is understood as meaning a device comprising at least one hot air drying device, which is arranged at a distance from the fibrous web and acts on a surface of the fibrous web oriented toward it for drying purposes. It is a dry principle free of direct contact of the fibrous web with the drying device. In the impingement drying device, the fibrous web is guided along a straight or curved drying section by an endlessly circulating belt, which is preferably air-permeable and, in this case, in particular, is designed as a drying belt. According to According to a further embodiment, the guidance of the fibrous web can also take place supported on an air-impermeable belt.

The surface of the fibrous web not supported by the belt, in particular the dryer fabric, is exposed to a hot air device. The support of the endless circulating air-impermeable belt is usually via guide rollers, which may also be evacuated. In this case, a support can also take place in the region of the extent of the impingement drying device viewed in the direction of passage of the fibrous web, but is not mandatory. The guide rolls can be vacuumed according to a particularly advantageous embodiment. The solution according to the invention for increasing the moisture content is particularly advantageous in the case of this type of non-contact drying, in which there is little or no support with regard to the guidance of the fibrous web on the covering by the supporting elements in the impingement drying region. This disadvantage is compensated in a simple way by increasing the moisture content.

Temporary means that the moisture content of the fibrous web and / or clothing is increased over a predefinable period of time. The period of time includes at least one period, which is characterized by the duration of the startup or the winding of the fibrous web after a fibrous web break. The moistening takes place at least until reaching device for contact drying by the fibrous web. This period is characterized by an increased risk of detachment of the fibrous web in the region of the drying section free of contact drying in the drying apparatus and the resulting damage. Preferably, this period is determined at least from the period of time from the decrease of the fibrous web at the forming device to reaching the device for contact drying by the fibrous web, most preferably from the activation of the headbox until reaching the device for contact drying by the fibrous web.

According to a particularly advantageous embodiment, the transfer of the fibrous web between the forming device and drying device is free from a free train. The fibrous web is thereby supported at least on one side in all areas of its guide path between the forming device and the drying device, whereby a secure web guide at elevated machine speeds can be achieved.

The guidance of the fibrous web from the forming device via a press device to the drying device is carried out within the press device supported on at least one side by means of a covering. That the press device is designed such that no guide is provided directly on the outer circumference of the shell of a smooth roller free of support by a covering. As a result, the fibrous web is exposed only in the area of the drying device to the device for contact drying, in particular drying cylinder again a corresponding for the web-wide transfer essential tensile stress.

If a plurality of successively arranged impingement drying devices are preferably provided to increase the dry content, they are arranged and designed such that they each become active on different fibrous web surfaces, so that the drying process takes place as evenly as possible from both sides. The impingement drying devices are for this purpose preferably arranged at an angle to each other, most preferably perpendicular to each other.

The increase of the moisture content can be done in different ways. According to a first embodiment, a direct increase is achieved by additional application of moistening medium. According to a second embodiment can be dispensed with additional aids and the increase in moisture content by changing the process parameters in the press device during startup or transfer in the said period can be achieved, in particular the press device is relieved in this period, whereby the fibrous web at the end of this one increased Has moisture content compared to normal operation. The possibility of the second embodiment is combined with insufficient moisture content with the first option.

Preferably, an increase in the total moisture in the transfer area is realized by the application of moistening agent. This is at least partially applied in the transfer area either directly on the fibrous web or on the, the fibrous web supporting fabric.

The order of moistening agent can be controlled. In this case, the amount and / or composition of the humectant can be varied and adapted to the specific boundary conditions in the order area.

According to an advantageous embodiment, the application of wetting agent takes place in the width direction at least in the edge regions of the fibrous web or the regions of the fabric which support the edge regions of the fibrous web, which are considered to be particularly critical regions during the transfer process. Furthermore, it is conceivable also partially in the width direction, i. apply moistening agent in strips over the width of the web. In each case, the moisture content in the contact area between the clothing and the fibrous web is thus at least partially increased.

The fibrous web and / or the fabric supporting the fibrous web is moistened in a particularly advantageous manner over its entire width, i. when mounting on the changing width of the fibrous web.

The moistening agent is preferably applied to the fibrous web supporting the dryer fabric before the takeover of the fibrous web to this from an upstream device. The upstream device may be a press device or another impingement dryer.

The moistening viewed in the width direction of the fibrous web is preferably uniform.

In order to increase and adjust the moisture content, the fibrous web and / or the fabric supporting the fibrous web can be moistened in areas arranged at a distance from one another in the circumferential direction of the fabric or in the direction of passage of the fibrous web.

The moistening agent used is preferably a fluid, in particular water and / or a fluid-gas mixture and / or steam. This can be provided by already existing in the machine for the production of fibrous webs and preferably over the entire operating life active circuits or systems. The cost of a sporadic and short-term required provision can be kept low. Furthermore, waste products from the operation of other sections of the machine may be used to make fibrous webs.

So that the moistening agent does not adversely affect the surface quality of the fibrous web, the amount of moistening agent is chosen so that a sufficient adhesive effect is achieved, but does not cause any changes in the surface quality of the fibrous web, in particular roughness and the near-surface composition of the fibrous web. The order is carried out either continuously or discontinuously, whereby the method of application within the predefined period of time can also vary depending on the requirement.

The moistening agent can be applied by means of at least one nozzle, preferably a plurality of individually or in groups controllable nozzles in the free jet.

In an advantageous further development according to the first embodiment, it is provided that, within the press device, the pressing pressure on at least one press device over a predefined period of time also during the Start up or after a pulp web tear to increase. For this purpose, the pressing pressure on the first press device in the feed direction of the fibrous web is preferably increased within the press device over the predefined period of time. This increases the strength of the fibrous web due to the higher initial dry content on transfer to the dryer.

The machine for producing fibrous webs, in particular paper, board or tissue webs, comprising a wet part with a forming device and a downstream press device and a downstream of the wet part drying device with at least one drying section free of contact drying, in particular at least one impingement drying device, is characterized in that at least one device for moistening the fibrous web and / or the covering of the impingement drying device is provided.

According to a particularly advantageous embodiment for draft-free transfer, the number of takeover areas is minimized and the, the fibrous web from the last press means continuing stringing supplied directly to the impingement drying device, in particular along the hot air dryer. That is, the fibrous web continuing from the last press device covering at the same time forms the fibrous web supporting clothing within the drying section of the impingement drying device, which is formed by a guided through the last press means felt or transfer belt. As a result, the number of transfer areas for the fibrous web is minimized and, in particular, the transition between press device and drying device, in particular impingement drying device, is closed. By minimizing the number of handover areas, the number of areas where it is necessary to ensure takeover and thus the number of potential problem areas is also reduced. Furthermore, the number of required guide and deflection rollers minimized. The web guide can be done over very long distances free of direction changes.

According to a particularly advantageous embodiment, the press device comprises at least one, preferably two or three press devices, each with two, a press nip forming press rollers, wherein the press nips are connected in the fibrous web passage direction one behind the other. The press nips can be formed as a simple press nip or extended press nips, in particular shoe press nips. Through this, the fibrous web is usually passed between two endless belts, in particular in the form of felt belts. These are porous bands that are permeable to air and have a storage volume for fluids.

The covering within the individual impingement drying section is supported by at least one, but preferably two or more, spaced-apart guide rollers.

Figur 1a und 1b

verdeutlichen in schematisiert vereinfachter Darstellung einer Maschine zur Herstellung einer Faserstoffbahn das Grundverfahren zum bahnbreiten Überführen einer Faserstoffbahn;

Figur 2

verdeutlicht in schematisiert vereinfachter Darstellung eine erste vorteilhafte Ausführung;

Figur 3

verdeutlicht in schematisiert vereinfachter Darstellung eine zweite vorteilhafte Ausführung.

The solution according to the invention is explained below with reference to figures. It details the following:

FIGS. 1a and 1b

illustrate in schematic simplified representation of a machine for producing a fibrous web, the basic method for web-wide transfer of a fibrous web;

FIG. 2

illustrates in schematic simplified representation of a first advantageous embodiment;

FIG. 3

illustrates in schematic simplified representation of a second advantageous embodiment.

The FIGS. 1a and 1b illustrate in a schematic simplified representation of the basic structure of a machine 1 for the production of webs, in particular fibrous webs F in the form of paper, board or tissue webs, the basic principle of the inventive method for web-wide transfer of the fibrous web F. When creating a coordinate system describes the longitudinal direction, which corresponds to the direction of passage of the fibrous web F through the machine and is referred to as the machine direction MD, the X direction, while the width direction corresponds to the Y direction and is referred to as the CD direction. In this case, the machine 1 comprises a wet end 2 and a drying section 3 adjoining it and arranged downstream of the resulting fibrous web F of the wet end 2. The wet end 2 comprises a forming device 4 and a press device 5 arranged downstream of the latter. Headbox not shown here, introduced a pulp suspension S and dehydrated by means of drainage elements and taking advantage of at least one of the following principles: hydrodynamic forces, centrifugal force, application of negative pressure, Druckimpulteinbringung. By the parameters describing the dewatering process, the structure of the fibrous web F in the thickness direction thereof is formed. At the end of the forming device 4 is in the direction of passage, ie viewed in the longitudinal direction of the machine, a fibrous web F before, which is further dewatered in the press apparatus 5. After leaving the press device 5, the fibrous web F, which is already characterized by a high dry content at the end of the press device 5, is fed to a dry part 3, in particular a drying device 6. The transfer is preferably carried out free of a free train, ie always supported by a fabric or a conveyor belt. The drying device 6 is constructed such that it is characterized by a first drying section I free of contact drying and a second drying section II with contact drying, in particular at least one device 24 for contact drying. For this purpose, the drying device 6 comprises at least one device 7 for at least indirect drying in the form of an impingement drying device. This is characterized by a drying section TS for the fibrous web F, in which it is supported on an air-permeable, in particular porous band in the form of a dryer fabric T along a spaced apart arranged for this blast hood, in particular hot air drying device 8. At least indirectly means that no contact drying is provided as in drying cylinder arrangements, but the fibrous web F spaced along the drying device is guided. Preferably, the fibrous web F is guided along a straight or slightly curved drying section TS. In this case, when transferring the fibrous web F, in particular during start-up or after a fibrous web tear, there is the problem that it is possible to lift it off in the area of the impingement drying device, in particular between the drying wire T and the hot air drying device 8. This can lead to an impairment of the functioning of the machine 1, in particular at high speeds due to uncontrolled accumulation of the fibrous web F between the dryer fabric belt T and the hot-air drying device 8. However, these impairments can in turn result in an undesired re-pulp web tear or even loss of production.

To avoid this problem, it is inventively provided that in the transfer area between a forming device 4 and the drying device 6, a device 9 for increasing the total moisture of the fibrous web F supporting clothing and / or the fibrous web F is provided in the transfer area 18. This device 9 acts either directly on the fibrous web F or indirectly on the fibrous web F on the, these supporting clothing. Transfer area 18 is understood to mean a region in which the fibrous web is transferred between two functional devices connected in series. These may be part of a process section of the machine 1 for the production of fibrous webs F or different process sections.

The method for transferring a fibrous web F is according to FIG. 1b Characterized in that in a first method step A1, the fibrous web F is removed by the width of the forming device 4 and is guided into the press device 5. This is done by means of a Abnahmesaugwalze. The fibrous web F is guided by the press device 5 at least always supported on one side by a stringing. Preferably, in order to increase the strength of the fibrous web F, the pressing pressure in the press device 5 can be temporarily increased during the transfer process - A2. According to the invention is to support the railway-wide transfer of the Fibrous web F of the forming device 4 via the press device 5 to the drying device 6 via the hot air drying 8, the means 9 for increasing the moisture content of the fibrous web F supporting fabric and / or fibrous web F provided in the transfer area 18. For this purpose, at least during the transfer until the passage of a device 24 for contact drying in the contact drying section II of the fibrous web F, the moisture content of the covering and / or fibrous web F is temporarily increased. This happens in a process step A3. Following this, according to A4, a strip can be transferred in the contact drying section II, the strip being brought to the full width of the fibrous web during stable running. The moistening is carried out at least until the fibrous web F passes through the device 24, so that the device 9 is deactivated.

The increase in the total moisture content of the fabric and / or supported by this fibrous web F takes place, as already stated, directly or indirectly. According to a particularly advantageous embodiment indirectly, by moistening the fabric, the moistening takes place in a region which is provided before the transfer of the fibrous web F in a transfer region 18 in the receiving clothing. For the hot-air drying device 8, this means that the screen belt TS1 supporting the fibrous web F is moistened with a fluid, preferably in the form of water, in the form of an endlessly circulating screen belt in front of the transfer area 18 for the fibrous web F from the press device 5. The moistening is preferably carried out over the entire machine width, i. in CD direction, with constant intensity. The device 9 for increasing the total moisture preferably extends over the entire theoretically possible width of the fibrous web F, wherein a single or a plurality of nozzles are provided, which can be controlled individually or in groups.

According to an advantageous further development, the strength of the fibrous web F is increased prior to the entry of the fibrous web F into the drying device 6, in that the press capacity, in particular already at the first press device, is increased.

The FIG. 2 illustrates in a schematic simplified representation of a section of a machine 1 for the production of fibrous webs F with inventive increase in the moisture content of the fibrous web F and / or this supporting fabric. Visible here is only indicated in the form of a black box, the forming device 4 and the adjoining press device 5. The press device 5 is exemplified here as a tandem pressing device, ie there are two pressing devices 11.1 and 11.2 are provided, each forming a press nip 12.1 and 12.2. Each of the individual press devices 11.1 and 11.2 comprises two pressing rollers 13.11, 13.12 or 13.21, 13.22 which can be brought into operative connection and which form the press nip 12.1 or 12.2 through which the fibrous web F is preferably guided between two felt belts F11, F12 or F21 and F22 becomes. These are porous bands that are permeable to air and have a storage volume for fluids. F22 may also be an air-impermeable transfer belt in this case. The press nips can be formed as a simple press nip or extended press nips, in particular shoe press nips. The fibrous web F is guided always supported between the forming device 4 and the subsequent press device 5. This also applies to the press device 5 as well as the transfer either directly from the second press device 11.2 or indirectly via another, preferably air-permeable transfer belt 14 by means of two suction rolls S1 and S2, wherein S2 is arranged in the decreasing band, the drying section 3. The drying device 6 comprises at least one, preferably a plurality of hot-air drying devices 8 in the form of impingement drying devices, which is connected upstream of the actual drying cylinder TZ. In the illustrated case, a first impingement drying device 15 and a second impingement drying device 16 are provided. The first impingement drying device 15 is designed and arranged such that the fibrous web F, viewed in the machine direction MD, is guided essentially in the horizontal direction. For this purpose, the impingement drying device 15 is at a distance from the wire belt T1, in particular the surface 17 carrying the fibrous web F. arranged the screen belt T1. The fibrous web F is guided between the wire belt T1 and the impingement drying device 15. The guidance takes place in machine direction MD. The impingement drying device 15 extends in the longitudinal direction of the machine 1 viewed over a portion of this and is effective on a surface 10 of the fibrous web F. The second impingement drying device 16 is formed in the vertical direction and thus forms, as it were, a vertical impingement path, wherein preferably two such devices are provided here, which are designated 16.1 and 16.2, and two impingement paths TS2.1, TS2.2 describe successively take effect on the fibrous web F on the same surface 19, which is the surface 10 opposite. The transfer of the fibrous web F to the first impingement path TS1 via the wire conveyor T1. This is moistened in front of the transfer area 18, which in the case shown is characterized by the common guidance of the transfer belt 14 and the wire belt T1. The device 9, here 9.1 for increasing the total moisture is arranged in the direction of movement of the wire belt T1, in particular circulation direction, before the inlet into the transfer area 18 and serves to apply a moistening agent, preferably in the form of a fluid, on the surface 17 of the wire belt T1, which the fibrous web F should be supported. The screen belt T1, in particular the surface 17 of the screen belt, is then characterized by a higher moisture content, wherein this, in particular its adhesion forces, are used for the secure guidance of the fibrous web F. After passing through the first impingement path TS1 or passing the first hot air drying device 8, the fibrous web F is transferred to a second impingement path TS2, in particular TS2.1 and TS2.2. This is arranged such that now the other, second surface 19 of the fibrous web F is exposed directly to the impingement drying device 16. The acquisition takes place on a further screen belt TS2, by means of which the fibrous web F now supported on the previously exposed to the impingement drying device 15 surface 10 passes the second impingement path TS2. Again, the required adhesion of the fibrous web F, the screen belt T2, in particular the surface of the 22nd in front of a transfer area 21, which is formed by the wire belt T1 and the wire T2, moistened to increase the adhesion forces.

The moistening is always carried out before the contact of the fibrous web F with the acquiring band, in particular Siebband T1, T2 of the impingement drying device 15, 16 in the respective transfer areas 18, 21. The moistening, here in the form of facilities 9.1 and 9.2, include in the the simplest case, a rail-wide spray tube. More complex moistening units are also conceivable. According to a particularly advantageous embodiment, the subsequent to the impingement drying devices 15 and 16 drying elements, in particular means 24 for contact drying of the drying device 6, in particular the drying cylinder TZ, supported for web guide, that here a moistening for the purpose of better adhesion and leadership is made. In downstream drying cylinders TZ, according to a particularly advantageous embodiment, the surface 23 of the drying cylinder TZ, which comes into direct contact with the fibrous web F, is moistened. For this purpose, a device 9.3 for moistening the surface 23 of the fibrous web F supporting roller is provided.

According to a second, particularly advantageous embodiment, it is also possible to load the pressing device such that the fibrous web has a sufficiently high humidity when passing and passing through the drying device. This option can alternatively or additionally be made.

Clarifies the FIG. 2 an embodiment with provision of a separate transfer belt 14 or transfer belt, which is preferably designed as an air-permeable belt between the press device 5 and the drying device 6, shows the FIG. 3 an example of an embodiment according to FIG. 2 , but with integrated transfer free of additional transfer belts. In this embodiment, which is essentially the design according to FIG. 2 corresponds to the transfer area 18 can be dispensed with. That the Fibrous web F in the second press device 11.2 supporting band, in particular felt F22 is transferred to the drying device 6 and at the same time forms the fibrous web F supporting porous band in the impingement drying device 15. This is guided around guide rollers and preferably suction rolls.

Furthermore, the band F22 can also be designed as a transfer belt and be made impermeable to air, since in this case the adhesion between the fibrous web and belt is ensured. A humidification of this clothing is not required.

The solution according to the invention is suitable for machines for producing material webs, in particular fibrous webs of any desired design.

LIST OF REFERENCE NUMBERS

1

Machine for producing material webs

2

wet end

3

drying section

4

Forming device

5

press apparatus

6

dryer

7

Device for indirect drying

8th

Hot air drying system

9

Device for increasing the total moisture

10

surface

11.1, 11.2

press means

12.1, 12.2

press nip

13.11, 13.12

press roll

13:21, 13:22

press nip

14

conveyor belt

15

Impingement drying device

16

Impingement drying device

17

surface

18

Transfer area

19

surface

21

Transfer area

22

surface

23

surface

24

Device for contact drying

F11, F12

Filzband

F21, F22

Filzband

F22

transfer tape

F

Fibrous web

M

web

S

Fibrous suspension

T, T1, T2

Trockensiebband

TS, TS1, TS2

drying section

S1, S2

suction roll

I, II

drying section

Claims (38)

Method for web-width transfer of fibrous webs (F) in a machine (1) for producing a fibrous web (F), in particular a paper, board or tissue web, between a forming device (4) and a device (24) for contact drying of a drying device ( 6) via a drying section (I) free of contact drying, in particular via at least one impingement drying device (15, 16.1, 16.2),
characterized,
in that the moisture content of the fibrous web (F) and / or a covering (T, T1, T2) supporting the fibrous web is at least temporarily increased in at least a partial area of the transfer area between the forming device (4) and a device for contact drying. Method according to claim 1,
characterized,
that the moisture content of the fibrous web (F) and / or covering at least in the region of the contact areas of the fibrous web (F) and / or covering (T, T1, T2) is increased. Method according to claim 1 or 2,
characterized,
that the moisture content of the fibrous sheet (F) and / or covering is increased by a pre-definable period of time, wherein the increase during start-up or after a fiber web break at least until reaching the means (24) for contact drying by the fibrous web (F) is carried out. Method according to claim 3,
characterized,
that the time period is characterized by a period of time during start-up or after a fiber web break, which extends from the decrease of the fibrous web (F) to the forming device (4) until the means (24) for contact drying. Method according to one of claims 1 to 4,
characterized,
that the fibrous web (F) from the forming device (4) via a press device (5) to the drying device (6) is guided and the guide within the press device (5) at least supported on one side by means of a covering (F11, F12, F21, F22) , Method according to one of claims 1 to 5,
characterized,
that the transfer between the forming device (4) and means (24) for contact drying of a free-free train of the fibrous web (F) is carried out. Method according to one of claims 1 to 6,
characterized,
in that the fibrous web (F) in the impingement drying device (15, 16.1, 16.2) is guided on a drying wire belt (T, T1, T2) along a straight or curved drying section (TS, TS1, TS2.1, TS2.2). Method according to one of claims 1 to 7,
characterized,
in that a plurality of successively arranged impingement drying devices (15, 16.1, 16.2) are provided and these become effective on different surfaces (10, 19) of the fibrous web (F). Method according to one of claims 1 to 8,
characterized,
that the increase in the moisture content is carried out by applying moistening agent. Method according to claim 9,
characterized,
that the moistening agent is applied directly to the fibrous web (F). Method according to claim 9,
characterized,
in that the moistening agent is applied directly to a covering (T, T1, T2) supporting the fibrous web (F). Method according to claim 11,
characterized,
in that the moistening agent is applied to at least one clothing forming a transfer region (18, 21) - a covering which transfers the fibrous web (F) and a covering which takes over the fibrous web (F) - covering two in the machine direction (preferably at least on the fibrous web (F) MD) arranged one behind the other arranged devices for the treatment of a fibrous web (F), wherein the order in the direction of rotation of the respective fabric viewed before the entry into the transfer area (18, 21). Method according to one of claims 11 to 12,
characterized,
in that the moistening agent in the drying device (6) is applied to a fibrous web (F) supporting porous belt, in particular a dryer fabric belt (T, T1, T2) which guides the fibrous web (F) along an impingement drying device (15, 16) , Method according to claim 13,
characterized,
in that the moistening agent is applied in the drying device (6) to a porous belt, in particular a drying belt belt (T1), which supports the fibrous web (F) and forms a transfer region (18) between press device (5) and drying device (6). Method according to one of claims 9 to 14,
characterized,
in that the fibrous web (F) and / or the fabric (T, T1, T2, F22) supporting the fibrous web (F) is at least partially, preferably in the width direction, in the edge regions of the fibrous web (F) or the edge regions of the fibrous web (F). supporting areas of the clothing (T, T1, T2, F22) are moistened. Method according to one of claims 9 to 14,
characterized,
that the fibrous web (F) and / or, the fibrous web (F) supporting fabric is wetted across its entire width. Method according to one of claims 9 to 16,
characterized,
in that the fibrous web (F) and / or the fabric supporting the fibrous web (F) are moistened in regions arranged at a distance from one another in the circumferential direction of the fabric or in the direction of passage of the fibrous web (F). Method according to claim 16 or 17,
characterized,
that the humidification in the width direction (CD) and / or machine direction (MD) is uniform. Method according to one of claims 9 to 18,
characterized,
in that a fluid, in particular water and / or a fluid-gas mixture and / or steam, are used as wetting agent. Method according to one of claims 9 to 19,
characterized,
in that the moistening agent is applied in the free jet by means of at least one nozzle, preferably a plurality of individually or group-controllable nozzles. Method according to one of claims 9 to 20,
characterized,
in that the pressing pressure on at least one press device (11.1, 11.2) is temporarily increased within the press device (5). Method according to claim 21,
characterized,
in that within the press device (5) the pressing pressure is temporarily increased at the first press device (11.1) in the direction of passage of the fibrous web (F). Method according to one of claims 1 to 20,
characterized,
that the moisture content of the fibrous web (F) and / or this supporting fabric (T, T1, T2, F22) is increased by temporarily reducing the pressing performance within the press device (5) during the starting process, or a threading process according fibrous web break. Method according to one of claims 1 to 23,
characterized,
that the fibrous web (F) of the last, a press nip (12.2) forming press device (11.2) of the press device (5) with a band in the form of a string (F22) of the last press device decreasing band in the form of a transfer belt (14) Impingement drying device (15) is supplied. Method according to one of claims 1 to 24,
characterized,
that the fibrous web (F) of the last, a press nip (12.2) forming press device (11.2) of the press device (5) with a band of the clothing (F22) of the last press device (11.2) of the impingement drying device (15) fed directly through and this is passed. Machine (1) for producing fibrous webs, in particular paper, board or tissue webs, comprising a wet part (3) with a forming device (4) and one of these downstream press device (5) and a drying device (6) downstream of the wet part (3) ) with a device (24) for contact drying and at least one of these upstream drying section (I) free from contact drying, in particular at least one impingement drying device (15, 16.1, 16.2),
characterized,
in that at least one device (9, 9.1, 9.2) for increasing the moisture content of the fibrous web (F) and / or a covering (T, T1, T2, F22) supporting the fibrous web (F) is passed through the at least one impingement drying device ( 15, 16.1, 16.2) is provided. Machine (1) for producing fibrous webs (F) according to claim 26,
characterized,
in that the at least one device (9, 9.1, 9.2) for increasing the moisture content of fibrous web (F) and / or one of the Fibrous web (F) supporting clothing (T, T1, T2, F22) of a, a transfer area (18, 21) forming fabric - is assigned to a donating fabric or accepting clothing. Machine (1) for producing fibrous webs (F) according to claim 26 or 27,
characterized,
in that the at least one device (9, 9.1, 9.2) for increasing the moisture content of the fibrous web (F) and / or a covering (F22) supporting the fibrous web (F) has a transfer region (18) between press device (5) and drying device (6) ) is associated with training acquiring covering the drying device (6), in particular drying fabric belt (T1). Machine (1) for producing fibrous webs (F) according to one of Claims 26 to 28,
characterized,
in that the drying device (6) comprises at least two impingement drying devices (15, 16.1, 16.2) arranged successively in the direction of passage of the fibrous web (F), each forming and spacing at least one impingement drying section (TS1, TS2.1, TS2.2) to a, the fibrous web (F) leading Trockensiebband (T, T1, T2) are arranged, wherein each of the Trockensiebbänder (T, T1, T2) at least one means (9, 9.1, 9.2) for moistening the surface (17, 22) the Trockensiebbandes (T, T1, T2) is assigned before the takeover of the fibrous web (F). Machine (1) for producing fibrous webs (F) according to one of Claims 26 to 29,
characterized,
that the impingement drying devices (15, 16.1, 16.2) are arranged at an angle to each other, wherein at least two of the Impingement drying devices (15, 16.1, 16.2) on different surfaces (10, 19) of the fibrous web (F) are effective. Machine (1) for producing fibrous webs (F) according to one of Claims 26 to 30,
characterized,
in that the device (9, 9.1, 9.2) for increasing the moisture content comprises at least one spraying device, in particular a nozzle, extending over the machine width. Machine (1) for producing fibrous webs (F) according to one of Claims 26 to 31,
characterized,
that the moistening over the width of the clothing (T, T1, T2, F22) is controllable. Machine (1) for producing fibrous webs (F) according to one of Claims 26 to 32,
characterized,
in that the press device (5) comprises at least one press device (11.1, 11.2), preferably a plurality of press devices (11.1, 11.2) arranged one behind the other, each forming a press nip (12.1, 12.2) and the arrangement and guidance of the clothing between the press device (5) and drying device (6) is designed such that the guidance of the fibrous web (F) between the press device (5) and drying device (6) always supported by at least one covering (F11, F12, F21, F22). Machine (1) for producing fibrous webs (F) according to claim 33,
characterized,
in that between the last press device (11.1) of the press device (5) and the drying device (6) a transfer belt (14) for removing the fibrous web (F) from a covering of the last press device (11.2) and transfer to a covering (T, T1) of the drying device (6) is provided. Machine (1) for producing fibrous webs (F) according to claim 33,
characterized,
in that the covering (F22) continuing the fibrous web (F) in the last press device (11.2) forms the clothing supporting the fibrous web (F) within the drying section (TS1) of the impingement drying device (15). Machine (1) for producing fibrous webs (F) according to claim 35,
characterized,
in that the fabric (F) which continues the fibrous web (F) in the last press device (11.2) is designed as an air-impermeable belt. Machine (1) for producing fibrous webs (F) according to one of Claims 26 to 36,
characterized,
that the fabric (T, T1, T2) within each impingement drying system (TS1, TS2.1, TS2.2) by at least one, preferably two or more than two guide rollers are supported. Machine (1) for producing fibrous webs, in particular paper, board or tissue webs, comprising a wet part (3) with a forming device (4) and one of these downstream press device (5) and a drying device (6) downstream of the wet part (3) ) with a device (24) for contact drying and at least one of these upstream drying section (I) free from contact drying, in particular at least one impingement drying device (15, 16.1, 16.2),
characterized in that the press device (5) at least one press device (11.1, 11.2), preferably a plurality of successively arranged press devices (11.1, 11.2), each comprising a press nip (12.1, 12.2) form each other and the arrangement and guidance of the covering between press device (5) and drying device (6) is designed such that the leadership of the fibrous web (F ) between press device (5) and drying device (6) always supported by at least one string (F11, F12, F21, F22); wherein the fibrous web (F) in the last press device (11.2) continuing stringing (F22) forms the fibrous web (F) supporting fabric within the drying section (TS1) of the impingement drying device (15) and is designed as an air-impermeable belt.

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