DE102009027087A1 - Method of conditioning an endlessly circulating drying belt and drying device with a conditioning device - Google Patents

Abstract

The invention relates to a method for conditioning an endlessly circulating, on a partial region (5) of its circulation path a material web, in particular fibrous web (F), supporting drying wire belt (3), wherein the drying wire belt (3) in this area along at least one Durchströmungstrocknungseinrichtung (9, 9.1, 9.2) is guided, in which the drying wire belt (3) after separation from the material web in the return region (8) to the receiving area for the fibrous web (F) is cleaned. The invention is characterized in that the drying wire belt (3) in the return region (8) for influencing its dry content (TG) of at least one transversely to the direction of rotation of the dryer fabric belt (3) extending and at this effective blowing device (16) with a gaseous medium below Pressure in an effective range (W) is applied and flowed through. The drying device (1) according to the invention is characterized by at least one blowing device (16) in the direction of rotation in the return region (8) of the dryer fabric belt.

Description

The The invention relates to a method for conditioning an endless circulating, on a portion of its circulation path a material web, in particular Fibrous web supporting Trockensiebbandes, wherein the Dry screen belt in this area along at least one Durchströmungstrocknungseinrichtung is performed, in which the Trockensiebband after the Separation of the material web cleaned in the return area becomes.

The The invention further relates to a drying device for a Machine for producing a material web, in particular a Fibrous web in the form of a paper, board or tissue web, comprising at least one through-flow drying device, supporting the material web on a portion of its circulation path and at the Durchströmungstrockeneinrichtung leader Dry fabric belt and at least one device for applying Cleaning medium in the return area on the drying wire belt.

The main function of dryer fabrics in machines for making webs, especially fibrous webs, is to guide them along dryers, particularly contact or throughflow dryers. The fibrous web is then transferred separately from the dryer belt to other functional units within the machine. The drying wire belt runs after separation, ie delivery of the fibrous web to a further processing unit back to the point at which this has taken up the fibrous web. It is necessary to clean during the return of the dryer fabric for removing trapped fibers or other dirt particles in order to produce on the fibrous web in the supported guide on the individual drying devices no marks and thus to ensure a high surface quality. For cleaning, different devices are used, which are characterized essentially by conveying a cleaning medium, in particular fluid, through the drying wire belt. Devices are known with devices extending transversely to the machine direction across the width of the dryer fabric for applying a fluid to and through the belt, wherein a corresponding suction device is preferably arranged on the opposite side, which is the removal of the through the device, in particular the applied Cleaning fluid entrained particles is used. Furthermore, the cleaning fluid is removed via the suction device. In this case, a liquid as well as a liquid / gas mixture can be used as cleaning fluid. A method for conditioning a fabric, in particular a dryer fabric belt, by means of such a machine-wide suction device is exemplified in the document EP 1 725 710 B1 known.

One significant disadvantage of such embodiments is that the dry content of the dryer fabric in the receiving area for the fibrous web over the service life and / or varies greatly in machine and / or machine direction and thereby the fibrous web rewet in the higher percentage range over the dryer wire belt after receiving this experiences.

In particular, in the production of tissue webs using Durchströmungstrocknungseinrichtungen in which the fibrous web is supported on one or more Trockensiebbändern one or more Durchströmungstrocknungseinrichtungen, after which the fibrous web with already 60-75% dry content can be transferred to other units, remains after cleaning the Trockensiebbandes in the return area by means of a high-pressure cleaning device and a pipe suction in this still a residual moisture up to 26 g / m ² , which is then again in the field of recording the fibrous web. In order to eliminate this, in the following cycle, the drying wire belt in addition to the fibrous web must be heated and dried by increasing the drying capacity at the corresponding drying devices. The residual moisture remaining in the dryer wire belt thus causes an increase in the energy consumption of the drying devices.

Of the The invention is therefore based on the object, a method for conditioning a Trockensiebbandes in dryers with guide a fibrous web along at least one Durchströmungstrocknungseinrichtung further develop such that at the end of the return area in the Receiving area for the fibrous web a very high solids content and thus a low residual moisture present to the required Energy input to achieve the desired dry content reduce the fibrous web.

The solution according to the invention is characterized by the features of claims 1 and 18 characterized. Advantageous embodiments are described in the subclaims.

A process for conditioning an endlessly circulating, on a partial region of its circulation path a material web, in particular fibrous web supporting drying fabric belt, wherein the dryer fabric belt is guided in this area along at least one Durchströmungstrocknungseinrichtung, wherein the Trockensiebband is cleaned according to the invention in the return area to influence its dry content of at least one transverse to the direction of rotation of the dryer fabric belt extending and acting on this effective blowing device with a gaseous medium under pressure in an effective range becomes. For this purpose, the blowing device comprises at least two ledges forming an outlet opening, arranged parallel to one another in the direction of rotation and contacting one side of the drying wire belt, a contact strip and a drain strip.

Under Conditioning within the meaning of the invention is at least the process the influence of the dry content of the dryer fabric belt in the return after separation from the web after or during cleaning by drying before re-absorption of the web Understood.

By the inventive solution of the use a blowing device, the drying wire belt is primarily by Convection dried quickly and effectively. The achievable thereby high dry content allows a reduction of the required Energy input at the Durchströmungstrocknungseinrichtung on the actually required for drying the fibrous web Energy input.

In Particularly advantageous embodiment, it is provided that gaseous medium with a temperature in the range of 40 up to 90 ° C, preferably from 80 to 90 ° C, a higher moisture absorption through the glass medium to realize.

Of the Pressure with which the gaseous medium preferably by the Trockensiebband is moved, it is in a range of 0.1 to 0.5 bar, preferably selected from 0.2 to 0.3 bar. As a result, very high flow velocities are achieved the rapid absorption and removal of moisture as well as in the dry sieve belt contained by the impurities through the dryer fabric belt cause flowing gaseous medium.

to Conditioning, it is also intended, in addition to the pure drying process, which upon passing through the gaseous medium by The dry sieve also dirt particles and deposits in Flowed through the direction of flow, and at least one cleaning medium, in particular Apply cleaning fluid to the dryer fabric belt or to guide through this. The cleaning can be done for example by Application of at least one cleaning medium directly in front of the effective range the blowing device and / or within the effective range of the blowing device take place in the direction of rotation of the dryer fabric belt to this overlapping. Preferably, however, the effective range of the blowing device is carried out in this way and arranged that this with the cleaning device or behind this ends in the direction of rotation. This will ensure that actually a correspondingly high dry content and no additional humidification by the cleaning device is achieved after drying.

In a particularly advantageous embodiment of the direction of action the blower at least one cleaning medium, in particular cleaning fluid with the main direction component in or applied against the direction of rotation of the dryer fabric belt, so that here is a passage of the cleaning medium through the Trockensiebband with simultaneous deflection due to the action of the blowing device is achieved. The blowing pressure is higher than the through the cleaning device after passing through the dryer fabric on Cleaning medium, especially cleaning fluid prevailing pressure, so that this reversal is possible. By this arrangement is a repeated traversal, but at least a two-time Traversing the drying wire belt through the applied cleaning medium achieved and thus significantly improved the cleaning effect.

Of the Dry content of the dryer fabric belt is at least as a function one of the operation of the blowing device at least indirectly descriptive size, in particular the blowing power itself at least indirectly describing size, set. Under one, a certain size at least indirectly describing or characterizing size is doing a size, especially physical or chemical size understood either directly or indirectly describes this particular size, represents or is in a functional relationship with it, making an investigation about the functional relationships or by predefined dependencies between these closed back to this particular size can be.

In Particularly advantageously, the dry content can be controlled or in a most preferred embodiment also be regulated. For this purpose, a transverse profiling of the mode of operation the blowing device transverse to the direction of rotation.

The setting of the transverse profile possible by the variable adjustment of at least one size which at least indirectly describes the operation of the blowing device, wherein preferably a constant dry content transverse profile is to be achieved here, offers the advantage of setting the same conditions over the entire width of the drying wire belt to be able to.

in the In the simplest case, the setting of the at least one, the operation of the blowing device at least indirectly descriptive size transverse to the direction of rotation only as a function of a nominal dry content the Trockensiebbandes after the conditioning device and in front of or in the receiving area for the material web. In a particularly advantageous embodiment, the at least one, the operation of the blowing device at least indirectly descriptive size transverse to the direction of rotation, too as a function of an actual dry content cross profile (actual dry content transverse to the direction of circulation) before the inlet into the blowing device and / or as a function of an actual dry content cross profile of Trockensiebbandes set in the direction of rotation after the blowing device. This solution allows a sensitive control depending on the actually on the dryer wire belt present conditions, whereby by the consideration this also the adjustment of a certain dry content across to the direction of rotation is possible. The mode of operation can be the blower at least indirectly descriptive size controlled and / or regulated transversely to the direction of rotation and further as a control variable of a control and / or regulation be used of dry solids cross profile. especially the Control of the dry solids cross profile across the direction of the sieve allows you to compensate for local fluctuations.

The Adjustment by active adjustment can during operation respectively. This solution offers the advantage of adjustment very high dry contents of the dryer fabric belt in the receiving area, whereby the energy requirement for the subsequent flow drying can be significantly reduced. As at least one, the operation of the Blower at least medium bar descriptive size At least one of the blowing power can be transverse to the direction of rotation at least indirectly characterizing size and / or one of the properties of the medium of the blowing device at least indirectly descriptive size across be adjusted variably to the direction of rotation. Here are as the blowing performance at least indirectly characterizing sizes the cross-sectional geometry and / or dimensioning of the outlet opening at the blowing device transversely to the direction Sieblaufrichtung descriptive sizes and / or the operating parameters when coupling the blowing device with a pressure source, in particular pressure and flow velocity understood the medium.

The variable adjustment of the geometry and / or dimensioning of the Outlet opening is preferably on the change in position and / or elastic deformation of at least partial areas at least one of the outlet opening forming strips relative made to each other. In this case, the supply can also centrally and with only one single source of pressure little control engineering effort for the pressure control done because the applied pressure across the width of the dryer fabric belt can be kept constant. In contrast, in a variable pressure control across the width of the dryer fabric belt the design effort for the blowing device due to possible stationary and unprofiled version these forming strips are kept low.

• – Zustand und/oder Temperatur des Mediums;
• – Art des Mediums;
• – Menge des Mediums/Durchsatz.

As the properties of the medium of the blowing device at least indirectly descriptive size, for example, at least one of the following variables can be set variably transversely to the screen direction:

• - condition and / or temperature of the medium;
• - Type of medium;
• - Quantity of medium / throughput.

In a particularly advantageous embodiment will be at least two blowing devices connected in series, whereby in smaller Facilities without low energy expenditure a more sensitive setting is possible by the residence time within a drying device is significantly increased.

The constructive design according to the invention the drying device is characterized by the features of the claim 18 characterized. Advantageous embodiments are further described in the subclaims.

The solution according to the invention is hereinafter explained with reference to figures. In detail is the following shown:

1 illustrates in schematic simplified representation of the example of a section of a drying device, an arrangement according to the invention and operation of a device for conditioning an endlessly circulating drying wire belt;

2a illustrates an embodiment of a drying device with two through-flow drying devices;

2 B clarified by a detailed representation according to 2a the construction of a device for conditioning;

3b to 3d illustrate embodiments of cross-profiling of the device for applying a gaseous medium, in particular blowing device;

4 illustrates a series connection of blowing devices;

5 exemplifies the execution of a system for controlling / regulating the dry content.

The 1 illustrated in a schematic simplified representation of the example of a section of a drying device 1 an inventive arrangement and operation of a device 2 for conditioning an endlessly circulating drying wire belt 3 , The endless circulating dryer belt 3 is designed as a permeable, in particular for a gaseous medium permeable belt. Such drying devices 1 are part of a machine 4 for the production of material webs, in particular fibrous webs F in the form of paper-board or tissue webs. To illustrate the individual directions when installing in such a machine 4 is to the drying device 1 a coordinate system created. The X direction describes the longitudinal direction of the machine 4 which corresponds to the passage direction for the fibrous web F to be produced. This is therefore also referred to as machine direction MD. The Y direction corresponds to the direction perpendicular to the X direction in a horizontal plane, and is referred to as a width direction or a CD direction CD. The Z direction describes the direction perpendicular to the X, Y plane and illustrates the height direction.

The endless circulating dryer belt 3 is available as a loop. This serves a partial area 5 its circulation path of guidance and support of the fibrous web F. This subarea 5 corresponds to the guide area for the dryer wire belt 3 between a so-called acquisition or acquisition area 6 for the fibrous web F from an upstream functional unit I For example, press device, in which this to the dryer fabric belt 3 is passed and a separation area 7 in which the fibrous web F from the dryer fabric belt 3 removed and to another functional unit II is passed, characterized. Outside this subarea 5 there is a return of the dryer fabric belt 3 in the direction of circulation to the acquisition or takeover area 6 , This area is also called return area 8th designated. The fibrous web F is within the subarea 5 along at least one through-flow drying device 9 led and charged. The single flow drying device 9 is designed and arranged such that by means of this a medium for drying through the fibrous web F, in particular hot air can be passed. The fibrous web F is supported on the outside 3.1 of the dryer fabric belt 3 from. The flow can be from the inside 3.2 towards the outside 3.1 or preferably, to lift the fibrous web F from the dryer fabric belt 3 to avoid or to ensure a full-surface contact with this, in the opposite direction in the direction shown by arrows. Depending on the design of the flow device, the fibrous web F is blown with a gaseous medium having a predetermined temperature, preferably in the range of 80 to 90 ° C and at a pressure in the range of 0.2 to 0.3 bar in the appropriate direction, wherein the Flow through the fibrous web F and the supporting this Trockensiebband 3 a drying effect due to the enrichment of the blown air with moisture and discharge due to the impressed flow rate after exiting the dryer fabric belt 3 takes place, preferably the Durchströmungstrocknungseinrichtung 9 opposite from the fibrous web F free inside 3.2 of the dryer fabric belt 3 a suction device 18 is assigned, which serves for the removal of the flow medium.

The fibrous web F becomes after the Durchströmungstrocknungseinrichtung 9 with the dryer wire belt 3 continued and in the separation area 7 to the downstream functional unit II to hand over. Following this, the now free of the fibrous web F area of the endless circulating Trockensiebbandes 3 back to the reception area 6 guided. Within this return area 8th is the device 2 arranged for conditioning. This includes at least one device 14 for applying cleaning medium to the drying wire belt 3 with penetration of this with entrainment of debris and dirt particles and a device 16 for applying a gaseous medium under overpressure, in particular a blowing device for the purpose of drying the drying wire belt 3 , The function of the device 16 consists in addition to the improved removal of dirt from the dryer belt 3 in the increase of the reception area 6 dry solids content TG of the dry sieve belt 3 to avoid rewetting of the fibrous web F by a high moisture content on the surface of the outside 3.1 of the dryer fabric belt 3 , In a particularly advantageous manner, the flow takes place from the outside 3.1 to the inside 3.2 of the dryer fabric belt 3 , wherein preferably in the region of the inside means 17 are provided for suction. This ensures that the drying medium, which is preferably hot blast air at a predefined temperature in the range of 80 to 90 ° C, is used, with a pressure in the range of 0.2 to 0.3 bar from the outside 3.1 of the dryer fabric belt 3 is applied, the drying wire belt 3 flows through and on the inside 3.2 not absorbed after absorption of moisture but also dissipated.

By means of the device 16 Successful throughflow drying of the dryer fabric belt 3 becomes the dryer fabric belt 3 Volume-saving dried. Preferably, the device describes 16 , in particular the blowing device in the direction of rotation of the dryer fabric belt 3 considered, a so-called effective range, which is referred to here as W ₁₆ . This extends in the longitudinal direction, that is to say in the machine direction MD and transversely to the machine direction in the CD direction, preferably over the entire width of the dryer fabric belt 3 , The blowing device is preferably the device 14 arranged downstream of the application of cleaning medium or the effective ranges of both devices are arranged overlapping each other, wherein preferably the effective range of the device 16 in the direction of rotation of the dryer fabric belt 3 about the facility 14 for applying cleaning medium hinauserstreckt.

The 2 illustrates a particularly advantageous application of a device according to the invention in a drying device 1 a machine 4 for producing a tissue web. The basic structure of the drying device 1 regarding takeover area 6 , Subarea 5 and return area 8th corresponds to the in 1 described. In the case shown, however, two such Durchströmungstrocknungseinrichtungen 9.1 and 9.2 in the subarea 5 the circulation area of the dryer fabric belt 3 provided, which are effective on the fibrous web F in this area. Shown here is the takeover area 6 from an upstream functional unit I , in particular wire section, and the transfer area in the separation area 7 to the downstream functional unit II , comprising further drying devices, in particular a contact drying device in the form of a Yankee cylinder 13 , The Durchströmungstrocknungseinrichtungen 9.1 and 9.2 are connected in series and are run through one after the other. Each of the throughflow drying devices 9.1 and 9.2 in each case, for example, comprises a flow-through drum or a flow-through cylinder 10.1 and 10.2 , which in each case from the drying wire belt 3 is wrapped on a portion of its outer circumference. The fibrous web F is on the dryer fabric belt 3 over a partial area of the outer circumference of the individual flow-through cylinders 10.1 . 10.2 Circumferentially guided around this and exposed in this area a flow drying. The flow drum has a perforated shell, each having a device 11.1 . 11.2 for loading the fibrous web F at the dryer fabric from the belt 3 free side FO with hot air in the form of blown air hoods in the wrap around the outer circumference of the individual flow cylinder 10.1 . 10.2 assigned. The hot air flows through the fibrous web F, the dryer fabric belt 3 and the lateral surface of the flow cylinder 10.1 . 10.2 , In this case, within the wrap area of the dryer fabric belt 3 with the single flow cylinder 10.1 respectively 10.2 preferably provided within this a corresponding suction device, which dissipates the passing through the fibrous web F and moisture-absorbing medium. The fibrous web F is then in the separation area 7 , here by way of example by means of a suction and pressing roller 12 , to other functional units II pass, in the case illustrated by way of example to a so-called Yankee cylinder 13 in which it is a heated drying cylinder with a smooth surface for contact drying by guiding the fibrous web F with now the top FO directly supported on this. The transfer takes place in the case shown in between suction roll 12 and Yankee cylinders 13 formed press nip 14 ,

In the return area 8th is also a device here 2 arranged for conditioning. The 2 B illustrated by a detail view X according to 2a a particularly advantageous embodiment of this. In this case, the device comprises 2 a device preferably extending transversely to the machine direction MD 16 , in particular blowing device, comprising at least two strips, a first start-up strip lying in the direction of wire-winding direction 19 and a second spaced therefrom in the circumferential direction of the dryer fabric belt 3 arranged drainage bar 20 which an exit opening 21 for the blowing air. The outlet opening 21 describes the so-called blow slot, over which the heated gaseous medium is applied under pressure. The bars touch 19 . 20 , in particular the start bar 19 and the drain bar 20 with corresponding guide surfaces 22 and 23 each the drying wire belt 3 , especially the outside 3.1 , The outlet opening 21 describes in the direction of rotation and cross machine direction CD considered the effective range W _16th These are overlapping on the inside 3.2 medium 17 for suction, comprising at least one arranged at least one suction device. In the illustrated case, this comprises by way of example two suction zones S1 and S2 which, at least in the direction of rotation of the dryer fabric belt 3 can be acted upon differently. In this case, the suction zone S1 is the outlet opening 21 on the inside 3.2 of the dryer fabric belt 3 arranged opposite and extends at least over the extension of the effective range W ₁₆ in the circumferential direction, preferably beyond, while the second suction zone S2 is arranged downstream in the direction of rotation of the first suction zone S1. In a particularly advantageous manner is between the on or start bar 19 and the dryer fabric belt 3 a wedge-shaped, in Sieblaufrichtung adjusting narrowing gusset formed in which a Einrich tung 14 for applying cleaning medium, in particular water injection device opens. This is on the to the device 16 , in particular blowing device opposite side 3.2 of the dryer fabric belt 3 arranged. This will accomplish that via a facility 14 in the form of a high-pressure spraying device 15 or a plurality of fluid which can be applied in and transverse to the direction of rotation, at least twice the dryer fabric belt 3 happens by putting this first from the inside 3.2 towards the outside 3.1 of the dryer fabric belt 3 penetrates through it and from there due to the effect of the device 16 , in particular blowing device, is pushed back again in reverse order. As a result, a multiple cleaning effect is achieved by the cleaning medium several times the Trockensiebband 3 can happen. Thus, at least a two-stage cleaning is achieved with simultaneous drying effect. Further, the blown-out air-fluid mixture and the dissolved deposits through the means 17 sucked off, so that nebulization and entrainment of dissolved when blowing dirt particles are proven to be prevented. This effect can be assisted by the arrangement of deflectors, not shown here, which are located on the dryer fabric belt 3 Peel off the forming boundary layer. These are preferably also within the extension of the effective range W _{16 of} the device 16 on the inside of the dryer fabric belt 3 effective.

In addition, can also be in the inlet to the run-up bar 19 a device for the application of lubricating medium, in particular water are arranged under low pressure to between the run-up bar 19 and the dryer fabric belt 3 to form a hydrodynamic lubrication wedge.

According to a particularly advantageous embodiment, the arrangement of the device takes place 16 , in particular blowing device, while directly on the outside 3.1 of the dryer fabric belt 3 , whereby here in a particularly advantageous manner, the fibrous web F touching surface, that is the outside 3.1 , to the desired dry content TG is adjusted.

In the in the 1 . 2a and 2 B illustrated embodiments, the device in a simple manner 16 , in particular blowing device, machine-width trained. The machine-wide design of the outlet opening 21 made possible by a coupling with a supply unit for blowing air, in particular pressure medium source 29 a simple way of setting a dry content TG over the entire fibrous web width and thus Trockensiebiebbreite. In the simplest case, this is achieved by a blowing power at the device which is constant in the cross-machine direction CD 16 went out. In this case, the outlet is 21 preferably designed as a machine-wide blown slot with over the width constant cross-section and is applied uniformly on the cross machine direction CD with blowing air.

To ensure the highest possible dry contents TG on the dry sieve belt 3 guarantee, especially in the takeover sector 6 for the fibrous web F, the operation of the device 16 be modified at least indirectly characterizing sizes. These can be set as a function of the blowing power and / or geometric execution of the effective area W ₁₆ descriptive area. Since an enlargement of the area of the effective range by changing or enlarging the exit opening in the machine direction MD is limited by the required guarantee of a safe drying wire belt guide, according to FIG 3a in a view of the outlet 21 from below, an extension of the extension of the outlet opening 21 in the cross-machine direction direction to increase the effective area. These are the outlet opening 21 descriptive last- and arrival bar 19 . 20 - Machine transverse direction CD profiled formed, this profiling a wave-shaped course of the outlet opening 21 generated in the cross machine direction CD. The extension can also be achieved by other profile geometries in the cross machine direction, in which case always recesses and / or projections in the machine direction must be present on the individual strips.

In a particularly advantageous embodiment, to set a desired constant dry content TG or else dry content profile across the width of the dryer fabric belt, ie extension in the cross machine direction CD, a profiling takes place via the device 16 locally in the cross-machine direction CD on the dryer wire belt 3 effective blowing power. Here, a distinction is made between a so-called passive profiling or an active, ie during profiling possible profiling.

The possibility of passive profiling includes the fixed, ie constant over the operating time setting of the cross-machine direction CD different, the operation of the device 16 at least indirectly, ie directly or through functional relationships describable sizes. In the simplest case, this can be done by the geometry of the outlet opening 21 be different in the cross machine direction CD, ie be executed variable. Such an embodiment is for illustration in greatly exaggerated representation by way of example in 3b played. In this case, the cross section of the outlet opening varies 21 in Maschinenquerrich tung. This geometry of the outlet opening is given as a basic profiling and requires the same admission of the outlet opening 21 different blowing powers across the machine width. The profiling as basic profiling can be based on probability considerations for when cleaning the dryer fabric 3 be selected at this adjusting theoretical dry content TG. With uniform admission of the outlet opening 21 with blowing air during operation across the machine width is set with such a solution, a constant dry content cross profile over the entire service life.

Furthermore, it is conceivable to be able to actively carry out the profiling, this possibility also with the in the 3a and 3b combined options can be combined. Basically, while the operation of the device 16 at least indirectly characterizing variables as a function of the process parameters of the device 16 and / or constructive parameters of the device 16 be varied.

The 3c exemplified by an embodiment according to 3a the possibility of a zonal influence in the cross-machine direction CD on the dry content TG. This is in the simplest case with constant admission of the outlet opening 21 over the machine width with glass medium only the geometry of the outlet cross section of the outlet opening 21 locally modified in cross machine direction CD. The modification takes place in the case shown by way of example by the zonal subdivision of start-up and drain bar 19 . 20 in the cross-machine direction in partial areas 19.1 to 19.n . 20.1 to 20.n , which are each displaceable relative to each other in the machine direction MD.

The 3d illustrates a further embodiment of the possibility for controlling at least one of the operation of the blowing device 16 at least indirectly characterizing size, in particular the blowing power at least indirectly characterizing size. In this, the outlet opening 21 preferably of two parallel bars 19 . 20 formed, which are characterized by parallel exit surfaces and thus a constant outlet cross-section across the width. However, here is the outlet 21 sectionally or zonally transversely to the direction of rotation of the dryer fabric belt 3 subjected to different pressures p1-pn. The individual zones can be controlled individually or in groups. As a result, different pressure ranges can be realized transversely to the direction of rotation. In a particularly advantageous embodiment, the profile can also be varied in the direction of rotation. In this case, the outlet opening can be coupled with different zones in the direction of rotation.

4 by way of example, an embodiment of in the direction of rotation of the dryer wire belt 3 connected in series 16 , Exemplary are in the 4 two such blowing devices 16.1 . 16.2 each other in row of the outside 3.1 of the dryer fabric belt 3 associated with forming the effective ranges W _16.1 , W _16.2 . In this case, this embodiment is exemplary. Again, one or a plurality of facilities 14 be provided for the application of detergent, which on the inside and / or outside 3.2 . 3.1 of the dryer fabric belt 3 within the effective range of the respective institution 16.1 . 16.2 , this be arranged overlapping or upstream.

According to a particularly advantageous further development, under certain circumstances it may also be provided in order, if possible, to achieve a uniform dry content over the entire drying wire width 3 to achieve, in particular to avoid over-drying of the edges or other areas, the dry content TG of the dryer fabric 3 in front of the recording area 6 to control, preferably to regulate. Preferably, a predefined dry content TG is set, which is present at least in the receiving area or in front of it, and thus across the width of the dryer wire belt 3 same conditions for the fibrous web F guaranteed. According to a particularly advantageous embodiment, the dry content TG is preferably adjusted. The 5 illustrated by the example of a device 2 the assignment of a system 24 for controlling and / or regulating the dry content TG of the dryer fabric belt 3 , This includes a control and / or regulating device 25 connected to at least one or a plurality of detection devices 26.1 to 26.n . 27.1 to 27.n for detecting at least one, the dry content of the dryer fabric belt 3 before or after passing through the device 2 for conditioning at least indirectly characterizing size. In this case, preferably, a uniformly high starting dry content after passing through the device 2 across the width of the dryer fabric belt 3 desired, ie the setting of a setpoint Xsoll-TG over the entire Trockensiebbandbreite, which is fixed or may not be fallen below as the minimum value. With the individual detection devices 26.1 to 26.n respectively 27.1 to 27.n across the width of the dryer fabric belt 3 , that is in the cross machine direction CD before and / or after installation 16 are arranged locally transversely to the direction of rotation on the drying wire belt actual values of the respective dry content TG transversely to the direction of rotation at least indirectly descriptive variables for detecting the respective actual dry content cross profile Xist-TG1, Xist-TG2 determined. These are via the coupling of these detection devices 26.1 to 26.n . 27.1 to 27.n with the control and / or regulating device 25 this supplied and processed.

at For example, it is only a control of the dry content TG necessary to determine the current actual dry content cross profile and to control the adjusting devices for setting this.

In the control, a comparison between actual and setpoint, whereby dependency of the comparison on the respective control device 28.1 - 28.n the blowing power of the device 16 controlled or adjusted so that the desired setpoint values are achieved via the cross-machine direction CD.

In all versions, the determination of the blowing power required in each case depends on the rotational speed of the drying wire belt 3 and thus the length of stay with the institution 16 , Furthermore, the effect of the facilities 14 and 17 considered.

1

dryer

2

contraption for conditioning

3

Trockensiebband

3.1

outside

3.2

inside

4

machine for producing a material web, in particular fibrous web

5

subregion of the circulation route

6

On- or takeover area

7

separating region

8th

Return area

9 9.1, 9.2

Flow drying device

10.1, 10.2

Flow drum

11.1, 11.2

Blashaube

12

suction and press roll

13

Yankee cylinder

14

Facility for applying cleaning medium

15

High-pressure spray tube

16

Facility for applying a gaseous medium, in particular blower

17

medium for suction

18

suction

19

approach strip

19.1-19.n

subregion

20

progress bar

20.1-20.n

subregion

21

outlet opening

22

guide surface

23

guide surface

24

system for control and / or regulation

25

Tax- and / or control device

26.1-26.n

detector

27.1-27.n

detection devices

28.1-28.n

actuators

29

Pressure medium source

F

Fibrous web

FO

top

FU

bottom

MD

machine direction

CD

CMD

I

upstream functional unit

II

downstream functional unit

W ₁₆ , W _1.61 , W _16.2

Effective range of the device 16

S1, S2

suction zones

x, Y Z

coordinates

Xsoll-TG (y)

local Setpoint of the dry content transverse to the direction of rotation of the dryer fabric belt

Xist TG1 (y)

local Actual value of the dry content transverse to the direction of rotation of the dryer fabric belt in front of the blowing device

Xist TG2 (y)

local Actual value of the dry content transverse to the direction of rotation of the dryer fabric belt behind the blowing device

Y28.1-Y28.n

manipulated variable

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1725710 B1 [0003]

Claims (27)

Method for conditioning an endlessly circulating, on a partial area ( 5 ) of its circulation path a material web, in particular fibrous web (F) supporting drying wire belt ( 3 ), wherein the drying wire belt ( 3 ) in this area along at least one Durchströmungstrocknungseinrichtung ( 9 . 9.1 . 9.2 ), in which the drying wire belt ( 3 ) after separation from the material web in the return area ( 8th ) to the receiving area ( 6 ) is cleaned for the fibrous web (F), characterized in that the drying wire belt ( 3 ) in the return area ( 8th ) for influencing its dry content (TG) of at least one transverse to the direction of rotation of the dryer fabric belt ( 3 ) and at this effective blowing device ( 16 ) is subjected to a gaseous medium under pressure in an effective range (W ₁₆ , W _16.1 , W _16.2 ) and flows through it. Method according to claim 1, characterized in that that the gaseous medium with a temperature in the range from 40 to 90 ° C, preferably from 80 to 90 ° C applied becomes. Method according to one of claims 1 or 2, characterized in that the gaseous medium under a pressure of 0.1 to 0.5 bar, preferably applied from 0.2 to 0.3 bar becomes. Method according to one of claims 1 or 3, characterized in that the drying wire belt ( 3 ) the effective range (W ₁₆ , W _16.1 , W _1.62 ) of the at least one blowing device ( 16 ) is applied upstream of at least one cleaning medium and / or penetrated by this. Method according to one of claims 1 to 4, characterized in that the drying wire belt ( 3 ) the effective range (W ₁₆ , W _16.1 , W _16.2 ) of the at least one blowing device ( 16 ) is acted upon overlapping with at least one cleaning medium and / or interspersed by this. Method according to one of claims 4 or 5, characterized in that the drying wire belt ( 3 ) with the at least one cleaning medium having a main directional component in the direction of rotation of the drying wire belt ( 3 ) the direction of action of the at least one blowing device ( 16 ) is applied in opposite directions and / or interspersed by this. Method according to one of claims 4 or 5, characterized in that the drying wire belt ( 3 ) with the at least one cleaning medium having a main directional component in the direction of rotation of the drying wire belt ( 3 ) the direction of action of the at least one blowing device ( 16 ) is applied in opposite directions and / or interspersed by this. Method according to one of claims 1 or 7, characterized in that the dry content (TG) of the dryer fabric belt ( 3 ) as a function of at least one, the operation of the blowing device ( 16 ) at least indirectly descriptive size, in particular the Blasleistung at least indirectly descriptive size, is adjustable. A method according to claim 8, characterized in that the operation of the blowing device ( 16 ) at least indirectly descriptive variable as a function of at least one of the following variables is adjustable: - one of the geometry and / or dimensioning of the outlet opening at least indirectly descriptive size; A variable describing at least one process parameter, at least indirectly, such as pressure, temperature; - A size of the glass medium used at least indirectly describing size as type, composition. Method according to one of claims 8 or 9, characterized in that at least one, the operation of the blowing device ( 16 ) at least indirectly descriptive size, in particular at least one blow performance at least indirectly characterizing size in the direction of rotation of the dryer fabric belt ( 3 ) and / or is variably adjustable transversely to this. A method according to claim 10, characterized in that the effective range (W ₁₆ , W _16.1 , W _16.2 ) of the at least one blowing device ( 16 ), in particular the cross-sectional geometry and / or dimensioning of the outlet opening ( 21 ) in the direction of rotation of the dryer fabric belt ( 3 ) and / or is variably adjustable transversely to this. Method according to one of claims 8 to 11, characterized in that the outlet opening ( 21 ) acting pressure in the direction of rotation of the dryer fabric belt ( 3 ) and / or is variably adjustable transversely to this. Method according to one of claims 1 to 12, characterized in that the dry content (TG) in dependence on a nominal dry content (Xsoll-TG (y)) transversely to the direction of rotation of the dryer fabric belt ( 3 ) before the acquisition or acquisition area ( 6 ) is controlled for the material web. Method according to one of claims 1 to 13, characterized in that the dry content (TG) is regulated as a function of at least one of the following variables: - desired dry content (Xsoll-TG (y)) transversely to the direction of rotation of the dryer fabric belt ( 3 ) before the acquisition or acquisition area ( 6 ) for the material web - actual dry content (Xist-TG (y)) transverse to the direction of rotation of the dryer fabric belt ( 3 ) before and / or after the effective range (W ₁₆ , W _16.1 , W _16.2 ) of the blowing device ( 16 ). Method according to one of claims 1 to 14, characterized in that on the blowing device ( 16 ) opposite side of the dryer fabric belt ( 3 ) the effective range (W ₁₆ , W _16.1 , W _16.2 ) of the blowing device ( 16 ) Overlapping a negative pressure is applied. A method according to claim 13, characterized in that the negative pressure in and / or transverse to the direction of rotation of the dryer fabric belt ( 3 ) is adjustable. Method according to one of claims 1 to 16, characterized in that the drying wire belt ( 3 ) along a plurality of series-connected blowing devices ( 16 . 16.1 . 16.2 ) to be led. Drying device ( 1 ) for a machine ( 4 ) for producing a material web, in particular a fibrous web (F) in the form of a paper, board or tissue web, comprising at least one through-flow drying device ( 9 . 9.1 . 9.2 ), one on one subarea ( 5 ) of its circulation path, the material web supporting and at the at least one Durchströmungstrockeneinrichtung ( 9 . 9.1 . 9.2 ) along leading dryer fabric belt ( 3 ) and at least one device ( 2 ) for conditioning, comprising a device ( 14 ) for applying cleaning medium in the return area ( 8th ) on the drying wire belt ( 3 ), characterized in that the device ( 2 ) for conditioning at least one of the drying wire belt ( 3 ) in an effective range (W ₁₆ , W _16.1 , W _16.2 ) acting blowing device ( 16 ). Drying device ( 1 ) according to claim 18, characterized in that the at least one blowing device ( 16 ) of the institution ( 14 ) for applying cleaning medium in the direction of rotation of the dryer fabric belt ( 3 ) is connected downstream. Drying device ( 1 ) according to claim 16, characterized in that the at least one blowing device ( 16 ) of the institution ( 14 ) for applying cleaning medium in the direction of rotation of the dryer fabric belt ( 3 ) is arranged at least partially overlapping. Drying device ( 1 ) according to one of claims 16 to 18, characterized in that the blowing device ( 16 ) is profiled in and / or transverse to the direction of rotation. Drying device ( 1 ) according to claim 21, characterized in that the blowing device ( 16 ) at least two, an outlet opening ( 21 ) forming and arranged in the direction of rotation parallel to each other and one side of the dryer fabric belt ( 3 ) contacting the active region (W ₁₆ ) contacting strips ( 19 . 20 ) and the geometry and / or dimensioning of the outlet opening ( 21 ) in and / or transverse to the direction of rotation of the dryer fabric belt ( 3 ) is adjustable. Drying device ( 1 ) according to claim 21 or 22, characterized in that the blowing device ( 16 ) at least two, an outlet opening ( 21 ) forming and arranged in the direction of rotation parallel to each other and one side of the dryer fabric belt ( 3 ) contacting the active region (W ₁₆ ) contacting strips ( 19 . 20 ) and the pressure of the blowing medium at the outlet opening ( 21 ) in and / or transverse to the direction of rotation of the dryer fabric belt ( 3 ) is adjustable. Drying device ( 1 ) according to one of claims 18 to 23, characterized in that the plurality of blowing devices ( 16 . 16.1 . 16.2 ) is arranged in series one after the other. Drying device ( 1 ) according to one of claims 18 to 24, characterized in that the blowing device ( 16 ) a control and / or regulation system ( 24 ), comprising a control and / or regulating device ( 25 ) and with this - at least one device ( 26.1 - 26.n . 27.1 - 27.n ) for detecting actual values (Xist-TG (y)) of at least one, the dry content (TG) of the dryer fabric belt ( 3 ) transversely to the direction of rotation in front of and / or behind the blowing device ( 16 ) at least indirectly descriptive size; At least one adjusting device ( 28.1 - 28.n ) for adjusting the blowing performance at least indirectly descriptive sizes. Drying device ( 1 ) according to one of claims 18 to 25, characterized in that the individual blowing device ( 16 . 16.1 . 16.2 ) one page ( 3.1 . 3.2 ) of the dryer fabric belt ( 3 ) and on the opposite side of the dryer fabric belt ( 3 ) the effective range (W ₁₆ , W _16.1 , W _16.2 ) of the at least one blowing device ( 16 ) at least partially overlapping means ( 17 ) are arranged for suction. Drying device ( 1 ) after one of the Claims 18 to 26, characterized in that at least one individual blowing device ( 16 . 16.1 . 16.2 ) on the outside ( 3.1 ) of the dryer fabric belt ( 3 ) is arranged.