EP1304413A2 - Drying section and a smoothing device for the drying section - Google Patents

Abstract

A paper (22) mill assembly has a drying section (10) feeding an extended smoothing nip (12) interface formed by a shoe drum (14) facing a second pressing interface. Preferably 90 % of the drum mantle (14) diameter is positioned above the machine frame base line (16). <??>The drying nip (12) is located under a second heated drum (18) with a relatively inflexible mantle as compared with the shoe drum. The shoe drum has an internal oil cooling system and is thermally insulated. <??>An Independent claim is also included for a process to dry and smooth a paper or carton web in which the web is first dried to 60% preferably 70% and then fed through the extended smoothing nip. One part of the nip interface is heated and one is formed by an elastic e.g. polyurethane belt. The web residence period within the extended smoothing nip is 0.8 ms, followed by further drying.

Description

According to a first aspect, the invention relates to a drying section of a Machine for the production of a material web, in particular paper or Cardboard web, and a smoothing device in particular for use in such a dryer section.

Dryer sections with an integrated smoothing device are, for example, out the publications DE 196 02 697 A1, DE 195 48 307 A1, DE 196 04 675 C2, DE 44 07 405 C2 and F. Müller: "Paper manufacturing and its Maschinen II ", German press, 1928, known.

With the previously usual smoothing devices provided in the drying party the smoothing nips are formed by pairs of rollers. With fast running Paper machines is the dwell time of this type of calender Material web in the smoothing nip is too small, so that there is insufficient smoothness can be generated. Another disadvantage is that the Roll gap setting pressure increase or gradient is too large, which too can impair the paper web. On top of that the shape of the smoothing pressure curve in the machine or web running direction can not be chosen arbitrarily, but of the roller diameters is dependent. However, it is now often necessary to change the pressure curve in Change machine direction with different types of paper. Without such an adjustment of the pressure curve there is no optimal smoothing result without negatively influencing the remaining paper quality parameters possible. In these conventional smoothers moreover, it is also not possible to influence the smooth cross-sectional profile.

An object of the invention according to the first aspect is to improve To create dryer section as well as an improved smoothing device which the aforementioned disadvantages are eliminated. In particular, it should also ensure that maintenance and service work on the Smoothing device within the dryer section as efficiently as possible and without disrupt the operation of the manufacturing machine concerned can be. In particular, such a configuration is also used the smoothing device strives to ensure that this is optimal in a drying party can be used.

According to the invention according to the first aspect, this object is achieved through a dryer section of a machine for producing a material web, in particular paper or cardboard web, with one in the web running direction elongated smoothing nip, between two opposite one another Press surfaces is formed, of which at least one by one Shoe roll is formed, at least 70% and preferably at least 90% of the outside diameter of the shoe roller above the machine base lie.

Because of this training, a problem-free use is one of the education an extended smoothing shoe roller in a dryer section possible. In particular, the fact is taken into account that when using such a shoe roller as opposed to one Drying cylinder the jacket needs to be changed from time to time. On such a change is without the training according to the invention the risk of damage to the jacket is possible. In addition, the Changes take place relatively quickly, reducing the relevant downtimes the manufacturing machine, in particular paper machine, if possible is kept small. Accordingly, service work is also relatively easy feasible. A respective assembly or disassembly of the jacket the shoe roller is not only relatively fast, but also with little Device effort feasible. This applies in particular if according to a preferred embodiment of the invention Drying section the shoe roller lies completely above the machine floor. The resulting for the operation of the paper machine in question economic benefits are significant. As already mentioned, shorter downtimes achieved. Spacers can advantageously be used between the shoe roller bearing and a respective one Bearing block and / or cantilever elements are used. The stake of spacers and / or cantilever elements is related with the present invention of particular advantage. The coat can can be assembled and / or disassembled with the help of an entry device. This device can also be used as a lever for one-sided lifting the shoe roller, e.g. B. by the indoor crane. This enables that Removal of a spacer between the bearing and the bearing block and thus is threading and putting the coat over the shoe Shoe roll. In the cantilevering process, the shoe roller is introduced a bending moment raised on the opposite side, see above that the spacers are removed without lifting on the operating side can.

In certain cases, it can also be beneficial to whom both press surfaces are each formed by a shoe unit or shoe roller.

At least one of the two press surfaces is advantageously heated. At least one of the two press surfaces is preferably heated Smoothing surface provided.

According to a preferred embodiment of the dryer section according to the invention is the shoe roller with simultaneous internal cooling, e.g. B. by means of the lubricating oil, isolated from the environment by a hood. It is, for example, an insulation of the entire shoe roller with a Hood against the hot, humid environment with simultaneous internal Cooling z. B. possible by means of the lubricating oil. The elements in question are designed in such a way that their function due to the high temperature in a respective drying hood due to the large temperature differences between standstill and operation is not impaired.

Alternatively or additionally, however, there is also the possibility that preferably hooded shoe roller from the inside and / or to be cooled from the outside with cooling air.

It is also advantageous if in the direction of web travel before the extended Glättnip a humidification device for influencing the section Web moisture is provided transversely to the web running direction.

The extended smoothing nip can be in a single row or in a double row Drying group can be arranged.

The smoothing device according to the first aspect of the invention comprises an elongated smoothing nip in the direction of web travel, between two each other opposing pressing surfaces is formed, at least of which one formed by a shoe roller and at least one of which is heated is, preferably one of the two pressing surfaces by a Shoe roller and the other is formed by a drying cylinder. At least one of the two press surfaces is preferably heated Smoothing surface provided.

According to the invention, a smoothing device is thus proposed, which in is particularly suitable for use in a dryer section.

Is the smoothing nip between a shoe roller and a drying cylinder formed, the drying cylinder preferably has a compared to a conventional drying cylinder increased bending moment.

The drying cylinder can, for example, increase the bending moment an outside diameter> 1.5 m, in particular> 1.8 m, in particular 2 m and preferably> 2.4 m and / or a ribbed inner peripheral surface have.

It is also advantageous if the drying cylinder is controlled by deflection is. Such a deflection control can therefore be used in particular be provided, as is the case with shoe presses.

At least one of the two press surfaces is advantageously heated, with a surface temperature> 40 ° C, preferably> 60 ° C has.

The smoothing gap or the respective smoothing mechanism can, for example, within a sieve loop can be arranged. Basically, however, is also an arrangement outside such a sieve loop is conceivable.

The flexible jacket of the shoe roller is advantageously up to approximately 120 ° C. temperature resistant, this jacket preferably made of a corresponding thermally resilient plastic.

The flexible jacket of the shoe roller can in particular be made of elastomer Polymer-based material, e.g. B. made of polyurethane. The respective Sheath reinforcement is preferably made of elastomeric material, whose modulus of elasticity is greater than the modulus of elasticity of the elastomer Jacket material.

The oil used in the shoe roller for lubrication is preferably up to about 120 ° C temperature resistant. The quality of the oil used can So in particular be chosen so that temperatures up to 120 ° C no change in quality such as viscosity. The oil and the elastomeric jacket material are advantageously on top of one another Voted.

The outer diameter of the jacket of the shoe roller is preferably ≤ 1.8 m. This optimally suits the space available Accounted for, whereby respective air flows are not obstructed and accordingly the climate is not adversely affected.

In a preferred practical embodiment of the invention The shoe roller comprises a shoe fixed in the middle, so that thermal expansion is possible on both sides.

The shoe of the shoe roller can in particular by the one in question Lubricating oil are cooled, causing thermal expansion of the Shoe is reduced or prevented. Basically, there is also a Cooling from the inside possible with cooling air, cooling with lubricating oil is usually safer, simpler and more effective.

It is also advantageous if the shoe roller has means for eliminating it the friction occurring between due to thermal expansion Shoe and associated pressure unit is provided. Here is for example the use of hydrostatic pressure pistons, sliding elements or a pressing unit as in the case of those available on the market "FlexoNip" possible.

The shoe of the shoe roll is advantageously in the transverse direction and / or web running direction, can be applied sectionally or pressed. This enables smoothness profiling in the transverse direction, for example.

The shoe roller is advantageously z. B. isolated from the environment by a hood using the lubricating oil. It is, for example, an insulation of the entire shoe roller with a Hood against the hot, humid environment with simultaneous internal Cooling z. B. possible by means of the lubricating oil. Alternatively or additionally however, there is also the possibility of a respective with a hood provided shoe unit from the inside and / or outside with cooling air cool.

It is also advantageous if the shoe roller is assigned a hood that can be opened upwards and to the sides at least as far as that the opening created is at least as large as the outside diameter the shoe roller dimensioned and preferably by 1.5 times to Is dimensioned twice as large as the outside diameter of the shoe roller.

This ensures that service work on the shoe roller such as for example, a scraper change and / or the like during the Can be carried out without the climate in the hood and operating thus disrupting the production process.

Another important aspect of the invention relates to design the shoe roller and / or the drying cylinder at the respective edges. So occurs when operating a shoe roller within a dryer section the problem on that the hot surface of the drying cylinder especially at the edges not covered with paper due to radiation the preferably made of plastic jacket of the shoe roller heats up to an unacceptable extent, reducing its service life becomes. This can be remedied by the fact that the jacket material is made from a thermally resilient plastic. On the other hand point according to a further preferred practical embodiment the device according to the invention not from the material web covered edge areas of the two press surfaces, in particular in the Smoothing plane a distance from each other.

This is particularly advantageous if the drying cylinder is attached to the Edges are conical in shape and / or the stroke of the shoe roller assigned shoe is dimensioned so that the outer Edges of the circulating belt a distance from the opposite Press area results in> 5 mm, in particular> 8 mm and preferably > 12 mm.

It is also possible, for example, to design the drying cylinder in stages.

According to a second aspect, the invention relates to a method for combined drying and smoothing of a material web, in particular Paper or cardboard web, in a dryer section and also a corresponding one Smoothing device and a dryer section with such a smoothing device.

Methods and devices of the type just mentioned are for example from the publications DE 19548307 A1, DE 19604675 C2, DE 4407405 C2 and F. Müller: "Paper manufacturing and its machines II ", German press, 1928, known.

As already mentioned, in the previously common, in the dryer section provided smoothing devices, the smoothing nips formed by pairs of rollers. In high-speed paper machines this is the case with smoothing units the dwell time of the material web in the smoothing nip is too short, so that it is not sufficient Smoothness can be generated. Another disadvantage is in that the pressure increase or - occurring in the nip gradient is too large, which can damage the paper web can. In addition, the shape of the smoothing pressure curve in machines or Web direction can not be chosen arbitrarily, but from is dependent on the roller diameters. However, it is often necessary the course of pressure in the machine direction of different types of paper to change. Without such an adjustment of the pressure curve is no optimal smoothing result without negatively influencing the rest Paper quality parameters possible. With these conventional methods and devices is also no influence on the smooth cross-section possible. In addition, the smoothness that can be achieved is particularly fast Paper machines inadequate.

An object of the invention according to the second aspect is an improved one Process, an improved smoothing device and an improved dryer section of the aforementioned type, in which the previously mentioned disadvantages are eliminated.

• die Materialbahn zunächst bis zu einem vorgebbaren Trockengehalt > 60 %, insbesondere > 65 % und vorzugsweise > 70 % getrocknet wird,
• die diesen vorgebbaren Trockengehalt aufweisende Materialbahn durch einen in Bahnlaufrichtung verlängerten Glättnip geführt wird, der zwischen zwei einander gegenüberliegenden Pressflächen gebildet ist, von denen zumindest eine durch ein umlaufendes Band gebildet und von denen zumindest eine beheizt ist,
• die sich im verlängerten Glättnip ergebende Presszeit > 0,8 ms gewählt wird und
• die Materialbahn nach dem Glättnip weiter getrocknet wird.

According to the invention in accordance with the second aspect, this object is achieved by a method for combined drying and smoothing of a material web, in particular paper or cardboard web, in a dryer section, in which

• the material web is first dried to a predeterminable dry content> 60%, in particular> 65% and preferably> 70%,
• the material web having this predeterminable dry content is guided through a smoothing nip which is elongated in the web running direction and is formed between two opposing pressing surfaces, at least one of which is formed by a circumferential belt and at least one of which is heated,
• the pressing time resulting in the extended smoothing nip is selected> 0.8 ms and
• the material web is further dried after the smoothing nip.

The smoothing nip is therefore provided at such a position in the dryer section, has already started at the main shrinking process, so that the smoothness is retained and not again due to shrinking processes is deteriorating. Shrinking the surface of the The material web is getting rougher again.

In this case, at least one of the two pressing surfaces is preferably separated by one Shoe unit is formed, which is in particular a shoe roller can act. In the case of a shoe roller, its flexible jacket forms the belt in question.

The value R _a (mean roughness value) is advantageously <4 μm and preferably <3 μm for at least one of the two press surfaces.

The two press surfaces can be different or one have the same smoothness.

It is also advantageous if at least one of the two press surfaces as heated smoothing surface is provided.

A moistening device can be installed in front of the extended press nip in the direction of web travel for the sectional influencing of the web moisture across Web running direction are used.

The extended smoothing nip can be in a single-tier dryer section or Dryer group or also in a two-tier dryer section or dryer group be provided.

The smoothing device according to the second aspect of the invention comprises an elongated smoothing nip in the direction of web travel, between two each other opposing pressing surfaces is formed, at least of which one formed by a circumferential band and at least one of which is heated.

Because of this design, the smoothing device is special suitable for use in the dryer section.

According to a preferred embodiment of the invention Smoothing device is at least one of the two pressing surfaces by one Shoe unit formed, which is again a particular Shoe roller can act through the flexible jacket of the relevant revolving band is formed.

The two press surfaces can again be different or different have the same smoothness.

At least one of the two press surfaces is advantageously heated Smoothing surface provided.

In the direction of web travel in front of the extended smoothing nip there can be another Humidification device for sectional influence on the web moisture be provided transversely to the direction of web travel.

In a preferred practical embodiment of the invention Device is one of the two pressing surfaces by a rotating one Belt or one shoe unit and the other through a drying cylinder educated. The drying cylinder preferably has a compared to a conventional drying cylinder increased bending moment. To increase of the bending moment, the drying cylinder can, for example, be one Outside diameter> 1.5 m, in particular> 1.8 m and preferably > 2 m and / or have a ribbed inner circumferential surface.

The drying cylinder is preferably controlled by deflection. It can in particular, such a deflection control can be provided, as is the case with shoe presses.

At least one of the two press surfaces is advantageously heated, wherein it has a surface temperature> 40 ° C, preferably> 60 ° C.

The machine or web running speed can in particular > 450 m / min and preferably> 1200 m / min.

In an expedient practical embodiment of the invention Device is the web dwell time in the smoothing gap> 0.8 msec, in particular> 2 msec and preferably> 4 msec and / or in the direction of web travel measured shoe length> 30 mm and preferably> 60 mm.

The smoothing gap or the respective smoothing mechanism can, for example, within a sieve loop is arranged. Basically, however, is also one Arrangement outside sieve loops is conceivable.

Advantageously, at least one of the two press surfaces is marked by a up to about 120 ° C temperature-resistant circumferential band formed, wherein this band preferably from a correspondingly thermally resilient Plastic is made. The circulating belt can be, for example around the flexible band of a shoe unit, e.g. B. the flexible jacket act on a shoe roller.

The circulating belt can be made in particular of elastomeric material polymeric base, e.g. B. made of polyurethane.

The band reinforcement is preferably made of elastomeric material, whose modulus of elasticity is greater than the modulus of elasticity of the elastomer Strip material.

The oil used for lubrication in the respective shoe unit is expediently temperature-resistant up to 120 ° C. The quality of the Oil used can be chosen so that temperatures up to 120 ° C for no change in quality such as of viscosity. The oil and the elastomeric tape material are expediently coordinated.

Is the circumferential band through the flexible jacket of a shoe roller formed, the outer diameter is preferably ≤ 1.8 m. In order to is optimally taken into account the available space, whereby respective air flows are not hindered and accordingly the climate is not adversely affected.

Is one of the two pressing surfaces by a shoe roller and the other formed by a drying cylinder, the outer diameter is Shoe roller preferably less than or equal to the outside diameter of the Drying cylinder.

A central fixation of the respective shoe is also advantageous, whereby thermal expansion on both sides is possible.

The shoe of a respective shoe unit can in particular by Lubricating oil in question are cooled, with a thermal expansion of the shoe is reduced or prevented. Basically, though cooling from the inside with cooling air is also possible, cooling by means of However, lubricating oil is usually safer, easier and more effective.

The shoe unit is expediently provided with means for eliminating the due to thermal expansion friction between Provide shoe and assigned pressure unit. Here is for example the use of hydrostatic pressure pistons, sliding elements or one Pressing unit as in the case of the "FlexoNip" available on the market conceivable.

In a preferred practical embodiment of the invention The shoe unit comprises a sectioned section in the transverse direction Shoe over which the smoothness in the transverse direction, d. H. across the machine or section direction can be influenced. The smoothness is thus profilable in the transverse direction.

The shoe unit is advantageous with simultaneous internal cooling z. B. isolated from the environment by means of the lubricating oil through a hood. For example, it is an insulation of the entire shoe roller with a hood against the hot, humid environment at the same time internal cooling z. B. possible by means of the lubricating oil.

Alternatively or additionally, there is also the option of using a respective a shoe unit provided with a hood from the inside and / or from the outside To cool cooling air.

Another important aspect of the invention relates again to Design of the shoe unit or shoe roller and / or the drying cylinder on the respective edges. So occurs during operation, for example a shoe roller within a dryer section the problem that the hot surface of the drying cylinder especially on the not Paper covered edges preferably by radiation Plastic existing jacket of the shoe roller to an inadmissible extent heats up, reducing its lifespan. The remedy is on the one hand possible that the jacket material made of thermally resilient Plastic is made. On the other hand, according to a preferred practical embodiment of the device according to the invention the edge areas of the two press surfaces not covered by the material web a distance from one another in particular in the plane of the smoothing nip on. This is particularly advantageous if the drying cylinder is attached to the Edges are tapered and / or the stroke of the shoe unit assigned shoe is dimensioned so that the outer Edges of the circulating belt a distance from the opposite Press area results in> 5 mm, in particular> 8 mm and preferably> Is 12 mm. It is also possible, for example, to have the drying cylinder stepped perform.

In certain cases it is advantageous if the drying or smoothing cylinder is heated from the outside, e.g. B. electrically, by steam and / or like.

In an expedient practical embodiment of the invention The device is the drying or smoothing cylinder in the transverse direction considered sectionally heatable, which increases the sectional moisture of the material web can be influenced accordingly, so that the smooth cross profile can be controlled and / or regulated accordingly. This is particularly effective with a dry content> 60%.

It is also advantageous if the hood assigned to the shoe roller follows above and to the sides can be opened at least to the extent that the resulting opening at least as large as the outside diameter of the Shoe roller dimensioned and preferably 1.5 times to 2 times is dimensioned larger than the outside diameter of the shoe roller. Thereby ensures that service work on the shoe press such as for example, a scraper change and / or the like during the Can be carried out without the climate in the hood and operating thus disrupting the production process.

According to the invention, a dryer section of a machine is also used Production of a material web, in particular paper or cardboard web, with a smoothing device according to the second aspect of the invention proposed.

Another important aspect of the invention relates to the arrangement the shoe roller in the drying party. So according to a preferred one practical embodiment of the dry party according to the invention provided that at least 70% and preferably at least 90% of the The outer diameter of the shoe roller lies above the machine base. The shoe roller can in particular also completely over the Machine floor. This has the advantage of being a respective one Assembly or disassembly of the jacket of the shoe roller quickly and with little device effort can be performed. Who are for economic operation of the paper machine concerned Advantages are significant. This initially results in shorter downtimes. Advantageously, spacers between the bearing Shoe unit and a respective bearing block and / or cantilever elements be used. The use of spacers and / or cantilever elements is in connection with the present invention of special advantage. The jacket can be used with an entry device assembled and / or disassembled. This facility can be used at the same time as a lever for lifting the shoe roller on one side, e.g. B. by the Indoor crane, serve. This enables the removal of a spacer between the bearing and the bearing block and thus threading and putting on of the coat over the shoe of the shoe roller. When cantilevering the shoe roller by introducing a bending element on the opposite Side raised so that the spacers without lifting can be removed on the operating side.

According to the invention, an economical and technologically improved Solution for smoothing a material web such as in particular a paper or cardboard web specified, in particular for higher machine speeds is suitable.

Any combination of the two aspects of the invention is possible.

Fig. 1

eine schematische Teildarstellung einer einreihigen Trockenpartie mit einer Schuhwalze, die mit einem darüber angeordneten Trockenzylinder einen Glättnip bildet,

Fig. 2

eine schematische Teildarstellung einer einreihigen Trockenpartie mit einer Schuhwalze, die mit einem darunter angeordneten Trockenzylinder einen Glättnip bildet,

Fig. 3

eine schematische Längsschnitt-Teildarstellung einer beispielhaften Ausführungsform eines eine Schuhwalze sowie einen Trockenzylinder umfassenden Glättwerkes, bei der der Trockenzylinder an den Rändern konisch geformt ist,

Fig. 4

eine schematische Längsschnitt-Teildarstellung einer beispielhaften Ausführungsform eines eine Schuhwalze sowie einen Trockenzylinder umfassenden Glättwerkes, bei der der Hub des Schuhes so dimensioniert ist, dass sich an den äusseren Rändern des Schuhwalzenmantels ein Abstand zum gegenüberliegenden Trockenzylinder ergibt,

Fig. 5

eine schematische Längsschnitt-Teildarstellung einer beispielhaften Ausführungsform eines eine Schuhwalze sowie einen Trockenzylinder umfassenden Glättwerkes, bei der der Trockenzylinder gestuft ausgeführt ist,

Fig. 6

eine schematische Teildarstellung einer Trockenpartie, in der rein beispielhaft zwei mögliche Anordnungen einer der Bildung eines verlängerten Glättnips dienenden Schuhwalze dargestellt sind,

Fig. 7

eine schematische Längsschnitt-Teildarstellung einer beispielhaften Ausführungsform eines eine Schuhwalze sowie einen Trockenzylinder umfassenden Glättwerkes, bei der der Trockenzylinder an den Rändern konisch geformt ist,

Fig. 8

eine schematische Längsschnitt-Teildarstellung einer beispielhaften Ausführungsform eines eine Schuhwalze sowie einen Trockenzylinder umfassenden Glättwerkes, bei der der Hub des Schuhes so dimensioniert ist, dass sich an den äusseren Rändern des Schuhwalzenmantels ein Abstand zum gegenüberliegenden Trockenzylinder ergibt,

Fig. 9

eine schematische Längsschnitt-Teilddarstellung einer beispielhaften Ausführungsform eines eine Schuhwalze sowie einen Trockenzylinder umfassenden Glättwerkes, bei der der Trockenzylinder gestuft ausgeführt ist,

Fig. 10

eine schematische Teildarstellung einer einreihigen Trockenpartie mit einer Schuhwalze, die mit einem darüber angeordneten Trockenzylinder einen Glättnip bildet,

Fig. 11

eine schematische Teildarstellung einer einreihigen Trockenpartei mit einer Schuhwalze, die mit einem darunter angeordneten Trockenzylinder einen Glättnip bildet, und

Fig. 12

eine geschnittene Teildarstellung eines mit einer berippten Innenumfangsfläche versehenen Trockenzylinders.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing. The exemplary embodiments of FIGS. 1 to 5 relate primarily to the first aspect and FIGS. 6 to 12 primarily relate to the second aspect of the invention. Show it:

Fig. 1

2 shows a schematic partial illustration of a single-row dryer section with a shoe roller, which forms a smoothing nip with a drying cylinder arranged above it,

Fig. 2

1 shows a schematic partial illustration of a single-row dryer section with a shoe roller, which forms a smoothing nip with a drying cylinder arranged underneath,

Fig. 3

2 shows a schematic partial longitudinal section of an exemplary embodiment of a smoothing unit comprising a shoe roller and a drying cylinder, in which the drying cylinder is conically shaped at the edges,

Fig. 4

2 shows a schematic partial longitudinal section of an exemplary embodiment of a smoothing unit comprising a shoe roller and a drying cylinder, in which the stroke of the shoe is dimensioned such that there is a distance from the opposite drying cylinder at the outer edges of the shoe roller shell,

Fig. 5

2 shows a schematic partial longitudinal section of an exemplary embodiment of a smoothing unit comprising a shoe roller and a drying cylinder, in which the drying cylinder is designed in steps,

Fig. 6

2 shows a schematic partial representation of a dryer section, in which two possible arrangements of a shoe roller used to form an extended smoothing nip are shown purely by way of example,

Fig. 7

2 shows a schematic partial longitudinal section of an exemplary embodiment of a smoothing unit comprising a shoe roller and a drying cylinder, in which the drying cylinder is conically shaped at the edges,

Fig. 8

2 shows a schematic partial longitudinal section of an exemplary embodiment of a smoothing unit comprising a shoe roller and a drying cylinder, in which the stroke of the shoe is dimensioned such that there is a distance from the opposite drying cylinder at the outer edges of the shoe roller shell,

Fig. 9

2 shows a schematic partial longitudinal section of an exemplary embodiment of a smoothing unit comprising a shoe roller and a drying cylinder, in which the drying cylinder is designed in steps,

Fig. 10

2 shows a schematic partial illustration of a single-row dryer section with a shoe roller, which forms a smoothing nip with a drying cylinder arranged above it,

Fig. 11

is a schematic partial view of a single-row drying party with a shoe roller that forms a smoothing nip with a drying cylinder arranged underneath, and

Fig. 12

a partial sectional view of a drying cylinder provided with a ribbed inner peripheral surface.

Figures 1 and 2 each show a purely schematic partial representation a dryer section 10, each with an extension in the web running direction L. Smoothing nip 12, two possible arrangements purely by way of example the formation of such an extended smoothing nip 12 serving shoe roller 14 are shown.

The respective dryer section 10 can in particular be used for a machine Production of a material web, in particular paper and / or cardboard web, be assigned. The respective dryer section 10 can therefore in particular Be part of a paper machine.

Figures 1 and 2 each show a section of a single row Dryer section 10 or single-tier dryer group with above the base of the paper machine 16 arranged drying cylinders 18. Below the drying cylinder 18 web guide rollers 20 are provided, which in the present embodiment at least partially below the Paper machine floor 16 can be arranged.

The material web 22 is together with a respective conveyor belt, here drying wire 24 or 26, at least in sections meandering guided around the drying cylinders 18 and the web guide rollers 20. Are the web guide rollers 20 at such a distance from the drying cylinders 18 arranged that between the drying cylinders 18 and Web guide rollers 20 free running paths for the material web 22 and that result in respective drying wire 24 or 26.

The respective smoothing nip 12 elongated in the web running direction L is in each case formed between a shoe roll 14 and a drying cylinder 18. The shoe roller 14 is in one case directly below the relevant one Drying cylinder 18 arranged (see. Fig. 1), while in the other Case is arranged directly above the drying cylinder (see. Fig. 2).

While the shoe roller 14 in the exemplary embodiment according to FIG. 1 is provided outside the sieve loops, it is in the in Fig. 2nd illustrated embodiment within the loop of the dryer fabric 24 arranged. The loop in question is here, for example formed that the drying wire 24 in the area in question over at least an additional web guide roller 28, 30 is guided.

The two embodiments shown in FIGS. 1 and 2 is thus common that within the dry party 10 at least one in Web running direction L extended smoothing nip 12 is provided, which between two opposing pressing surfaces is formed, one of which at least one is formed by a shoe roller 14. Thereby lie at least 70% and preferably at least 90% of the shoe roll outer diameter above the machine floor 16. In the two shown Embodiments, the shoe roller 14 is completely complete above the machine floor 16.

The respective shoe roller 14 comprises at least one shoe 38, over which the flexible roll shell 44 to form the relevant extended press nips or nip 12 against the opposite Drying cylinder 18 can be pressed.

1 shows a schematic partial representation of a single-tier dryer section 10 with a shoe roll 14 which has a flexible jacket 44 and which, with a drying cylinder 18 arranged above it, forms a smoothing nip 12 extended in the web running direction L. The drying cylinder 18 opposite the shoe roller 14 is set higher than the remaining drying cylinders 18. Thus, in this exemplary embodiment according to FIG. 1, the axis of the drying cylinder 18 opposite the shoe roller 14 lies at a height h ₂ above the machine base 16, which is larger than that Height h ₁ , in which the remaining drying cylinders 18 are arranged.

In the present case, not only is the drying cylinder 18 concerned, but also the shoe roller 14 arranged underneath completely above the machine floor 16 arranged.

Despite the arrangement of the shoe roller 14 below the drying cylinder in question 18 thus a simple change of coat is possible.

As can be seen from this Fig. 1, is following the first drying cylinder 18 to be recognized within the loop of the relevant one Drying screen 24 a suction box 32 is provided. After that the material web 22 in the region of a deflecting roller 44 Conveyor belt 56, e.g. B. a dryer fabric or a smoothing belt, of which Dryer screen 24 taken over and together with the conveyor belt 26 through the elongated smoothing nip 12 in the web running direction L.

Behind the elongated smoothing nip 12, the material web 22 is in the area a deflection roller 28 through a drying wire 26 from the conveyor belt 26 taken over and together with this dryer 26 the following Drying cylinder 18 supplied.

Behind the extended smoothing nip 12 is inside the loop of the conveyor belt 56 a suction box 60 is provided. To the below the concerned drying cylinder 18 and within the loop of the conveyor belt 56 provided shoe roller 14 is an air-cooled, for example Hood 62 provided.

The cylinder 18 arranged above the shoe roller 14 is heated and serves as a smoothing cylinder.

The suctioned web guide or deflection rollers 20 have a smaller one Diameter than the drying cylinders 18.

As already mentioned, FIG. 2 shows a schematic partial illustration Embodiment of a single-tier dryer section, in which the shoe roller 14 with a drying cylinder 18 arranged below it in Web running direction L forms an elongated smoothing nip 12.

As can be seen from this FIG. 2, it lies below the shoe roller 14 arranged drying cylinders 18 somewhat lower than the neighboring ones Drying cylinder 18.

The cylinder forming the elongated smoothing nip 12 with the shoe roller 14 18 is heated again here and provided as a smoothing cylinder.

In the area of the web guide rollers 20 lying deeper than the cylinders 18 Railway stabilizers 64 are provided.

The shoe roller 14 is in the present case within the loop of the Dryer screen 24 arranged.

In the area of the drying or provided below the shoe roll 14 A high vacuum zone 66 is provided for the smoothing cylinder 18.

Fig. 3 shows a schematic longitudinal sectional partial representation of an example Embodiment of a shoe roll 14 and a drying cylinder 18 comprehensive smoothing unit to form a in the web running direction extended smoothing nips 12. The shoe roller 14 in question is particular can be used in a dryer section.

To prevent the hot surface of the drying cylinder 18 from becoming the edges 40 not covered with paper by radiation the coat of Shoe roller 14, which is preferably made of plastic, inadmissible Heats up mass, the arrangement is made so that the not of the Material web 22 covered edge areas of the two press surfaces in particular have a distance from each other in the smoothing plane.

In the present case, the drying cylinder 18 is at the edges 40 conically shaped that on the outer edges 42 of the circumferential flexible tape, d. H. here is the jacket 44 of the shoe roller 14 Distance d to the opposite smoothing surface, d. H. to the surface of the Drying cylinder 18, which expediently> 5 mm, in particular > 8 mm and preferably> 12 mm.

3, the basic structure of the to recognize shoe roller 14 concerned. Accordingly, this shoe roller includes 14 a flexible jacket running around a non-rotatable yoke 46 44, the at least one shoe 38 against the drying cylinder in question 18 can be pressed. The shoe 38 is by a variety of am Yoke 46 supported, e.g. B. hydraulic support elements 48. These support elements 48 can be, for example act hydraulic cylinder / piston assemblies. The flexible coat 44 is by means of a respective jacket attachment 50 on end plates 52 attached.

Fig. 4 shows another in a schematic longitudinal section exemplary embodiment of a shoe roller 14 and one Drying cylinder 18 smoothing unit to form a web running direction extended smoothing nips 12.

In this case, the stroke h of the shoe 38 is dimensioned such that the desired on the outer edges 42 of the shoe roll shell 44 Distance d results.

Fig. 5 shows again in a schematic partial longitudinal section another exemplary embodiment of a shoe roller 14 and a drying cylinder 18 smoothing unit to form a in Web running direction extended smoothing nips 12.

In this case, the drying cylinder 18 is designed stepped to the outer edges 42 of the shoe roll shell 44 the desired Obtain distance d to the opposite drying cylinder 18.

6 shows a purely schematic partial representation of a dryer section 110, in the purely exemplary two possible arrangements of one of the education an elongated smoothing nip 112 or 112 'serving shoe roller 114 and 114 'are shown.

The dryer section 110 can in particular be a machine for manufacturing assigned to a material web, in particular paper or cardboard web his. The dryer section 110 can therefore in particular be part of a paper machine his.

6 shows a section of the dryer section 110 with a row from drying cylinders arranged above the paper machine base 116 118, whose axes lie in one plane, for example. Below the drying cylinder 118 web guide rollers 120 are provided, which at present exemplary embodiment at least for the most part below the Paper machine base 116 are arranged.

The material web 122 is together with a respective conveyor belt, here dryer wire 124 or 126, at least in sections meandering guided around the drying cylinders 118 and the web guide rollers 120. The web guide rollers 120 are at such a distance of the drying cylinders 118 arranged between the drying cylinders 118 and the web guide rollers 120 free running paths for the material web and the respective dryer fabric 124 or 126 result.

The smoothing nip 112, which is elongated in the web running direction L, is between one shoe roller 114 on top and a drying cylinder on the bottom 118 formed. The shoe roller 114 is z. B. directly above the relevant drying cylinder 118 arranged (see the left part of the Fig. 6). In addition, this shoe roller 114 is within a loop of the Dryer screen 124 provided. The loop in question is, for example formed in that the drying wire 124 in the area of a web guide roller 128 from the drying cylinder 118 and the one continued thereon Material web 122 separated and then via, for example, a Web guide roller 130 is guided before being in the area of another web guide roller 132 runs up again on the drying cylinder 118, whereby the Material web 122 through drying wire 124 back to the drying cylinder 118 is pressed. Instead of the one upper web guide roller 130 For example, the dryer wire 124 can also be spaced two provided web guide rollers 134, 136 are guided, whereby the loop is enlarged accordingly.

The with the relevant drying cylinder 118 in the web running direction L Extended shoe roll 114 'forming smoothing nip 112' is in one area diagonally above the relevant drying cylinder 118 and outside the loops of the two dryer fabrics 124, 126 arranged (see right part of Fig. 6).

It is thus a combined drying and smoothing of the material web 122 possible. The material web 122 is initially up to a predefinable one Dry content> 60%, in particular> 65% and preferably> 70% dried. The material web having this predeterminable dry content 122 is then extended by the respective web running direction L. Smoothing nip 112 and 112 'performed between two opposite one another Press surfaces is formed, one of which is formed by a all-round flexible band, here the flexible jacket of the concerned Shoe roll 114 or 114 ', and the other heated by the relevant one Drying cylinder is formed. The will be extended Smoothing nip 112 or 112 'resulting press time preferably selected> 0.8 ms. The material web follows the smoothing nip 112 or 112 ' 122 further dried.

The shoe roller 114 or 114 'comprises at least one shoe 138, over the flexible roll shell with the formation of an extended press nip or gap can be pressed against the drying cylinder 118 in question is.

Fig. 7 shows a schematic longitudinal sectional partial representation of an example Embodiment of a shoe roll 114 and a drying cylinder 118 comprehensive smoothing unit to form one in the direction of web travel extended smoothing nips 112.

To prevent the hot surface of the drying cylinder 118 on the non-paper covered edges 140 by radiation the coat 144 of the shoe roller 114, which is preferably made of plastic, in heats up to inadmissible mass, the arrangement is such that the edge regions of the two press surfaces not covered by the material web 122 a distance from one another in particular in the plane of the smoothing nip exhibit.

In the present case, the drying cylinder 118 is at the edges 140 shaped conically in such a way that the outer edges 142 of the rotating flexible belt, d. H. here is the jacket 144 of the Shoe roll 114, a distance d to the opposite smoothing surface, d. H. here to the surface of the drying cylinder 118, which expediently > 5 mm, in particular> 8 mm and preferably> 12 mm.

7, the basic structure of the to recognize the relevant shoe roller 114. After that, this shoe roller includes 114 a flexible jacket running around a non-rotatable yoke 146 144, which has at least one shoe 138 against the drying cylinder 118 can be pressed. The shoe 138 is supported by a variety of yokes 146 supported, e.g. B. hydraulic support elements 148. These support elements 148 can be hydraulic, for example Act cylinder / piston assemblies. The flexible jacket 144 is by means of a respective jacket fastening 150 on end disks 152 attached.

Fig. 8 shows another in a schematic longitudinal section exemplary embodiment of a shoe roll 114 and one Drying cylinder 118 comprising smoothing unit to form a web running direction extended smoothing nips 112.

In this case, the stroke h of the shoe 138 is dimensioned such that at the outer edges 142 of the shoe roll jacket 144 the desired one Distance d results.

FIG. 9 again shows a partial schematic longitudinal section Another exemplary embodiment of a shoe roller 114 and a drying cylinder 118 comprising smoothing unit to form an in Web running direction extended smoothing nips 112.

In this case, the drying cylinder 118 is designed stepped to the outer edges 142 of the shoe roll jacket 144 the desired To obtain distance d from the opposite drying cylinder 118.

Fig. 10 shows a schematic partial representation of a single-tier dryer section 110 with a shoe roll having a flexible jacket 144 114, the one with a drying cylinder 118 arranged above Web running direction forms elongated smoothing nip 112.

As can be seen from FIG. 10, the drying cylinder 118 opposite the shoe roller 114 must be set higher than the remaining drying cylinders. Thus, in the exemplary embodiment shown, the axis of the drying cylinder opposite the shoe roller 114 lies at a height H ₂ above the machine base 116, which is greater than the height H ₁ at which the remaining drying cylinders 118 are arranged.

In the present case, not only is the drying cylinder 118 concerned, but also the shoe roller 114 arranged underneath completely arranged above the machine base 116.

Despite the arrangement of the shoe roller 114 below a drying cylinder 118 a coat change is possible without any problems.

As can be seen from FIG. 10, is following the first drying cylinder 118 to be recognized within the loop of the relevant one Dryer screen 124 a suction box 154 is provided. In connection the material web 122 in the area of a deflecting roller 155 through a conveyor belt 156, e.g. B. a dryer fabric or a smoothing belt, taken from the dryer wire 124 and together with the Conveyor belt 156 through the smoothing nip extended in the direction of web travel L. 112 led.

The material web 122 is in the area behind the elongated smoothing nip 112 a deflection roller 158 through a dryer fabric 126 from the conveyor belt 156 taken over and together with this dryer 126 to the subsequent drying cylinder 118.

Behind the elongated smoothing nip 112 is inside the loop of the Conveyor belt 156 a suction box 160 is provided.

To the below the relevant drying cylinder 118 and within the loop of the conveyor belt 156 is provided shoe roll 114 an air-cooled hood 162, for example, is provided.

The cylinder 118 arranged above the shoe roller 114 is heated and serves as a smoothing cylinder.

The suctioned web guide or deflection rollers 120 have a smaller one Diameter than the cylinders 118.

11 shows a further exemplary embodiment in a schematic partial illustration a single-tier dryer section 110 with a shoe roller 114, the with a drying cylinder 118 arranged underneath one in the direction of web travel L forms an elongated smoothing nip 112.

As can be seen from FIG. 11, it lies below the shoe roller 114 arranged drying cylinders 118 slightly lower than the neighboring ones Drying cylinder 118.

The one that forms the elongated smoothing nip 112 with the shoe roller 114 Cylinder 118 is therefore heated again and provided as a smoothing cylinder.

In the area of the web guide rolls lying lower than the cylinders 118 here 120 web stabilizers 164 are provided.

The shoe roller 114 is the same as that shown in the left part of FIG. 6 Embodiment again within the loop of a dryer fabric 124 arranged.

In the area of the dryer provided below the shoe roller 114 A high vacuum zone 166 is provided for the smoothing cylinder 118.

Fig. 12 shows in a sectional partial representation one with a ribbed Drying cylinder 118 provided on the inner peripheral surface for use in a corresponding smoothing unit having a shoe roller. With the Ribs 170 provided on the inside of the jacket 168 of the drying cylinder 118 there is an increased bending moment with the shoe roller 114 extended drying or smoothing cylinder 118 forming the smoothing nip (cf. 6 to 11). This can, for example, in the circumferential direction extending ribs may be provided.

The exemplary embodiments of FIGS. 1 to 5 relate primarily the first aspect of the invention, while the embodiments of the Figures 6 to 12 relate primarily to the second aspect of the invention. However, any combinations of these are also according to the invention two aspects of the invention and thus also the different exemplary embodiments possible.

LIST OF REFERENCE NUMBERS

10

drying section

12

Glättnip

14

shoe roll

16

Paper machine base

18

drying cylinders

20

web guide

22

web

24

dryer

26

dryer

28

web guide

30

web guide

32

suction box

38

shoe

40

edge

42

outer edge

44

coat

46

yoke

48

support element

50

mantle mounts

52

end disk

54

deflecting

56

conveyor belt

58

deflecting

60

suction box

62

Hood

64

web stabilizer

66

High vacuum zone

110

drying section

112

Glättnip

112 '

Glättnip

114

shoe roll

114 '

shoe roll

116

Paper machine base

118

drying cylinders

120

web guide

122

web

124

dryer

126

dryer

128

web guide

130

web guide

132

web guide

134

web guide

136

web guide

138

shoe

140

edge

142

outer edge

144

coat

146

yoke

148

support element

150

mantle mounts

152

end disk

154

suction box

155

deflecting

156

conveyor belt

158

deflecting

160

suction box

162

Hood

164

web stabilizer

166

High vacuum zone

168

coat

H ₁

height

h ₂

height

L

Web direction

d

distance

G

distance

H

stroke

Claims (85)

Dryer section (10) of a machine for producing a material web (22), in particular paper or cardboard web, with an in Web running direction (L) extended smoothing nip (12) between two opposing pressing surfaces is formed, of which at least one is formed by a shoe roller (14), at least 70% and preferably at least 90% of the shoe roll outer diameter lie above the machine base (16). Dryer section according to claim 1,
characterized in that the shoe roller (14) lies completely above the machine base (16). Dryer section according to claim 1 or 2,
characterized in that spacers can be used between the bearing of the shoe roller (14) and a bearing block and / or that cantilever elements can be used. Dryer section according to one of the preceding claims,
characterized in that one of the two pressing surfaces is formed by a shoe roller (14) and the other by a roller or a cylinder, in particular a drying cylinder (18), with a jacket which is not flexible in comparison with the shoe roller jacket (44). Dryer section according to one of claims 1 to 3,
characterized in that both pressing surfaces are each formed by a shoe unit or shoe roller (14). Dryer section according to one of the preceding claims,
characterized in that at least one of the two press surfaces is heated. Dryer section according to one of the preceding claims,
characterized in that at least one of the two pressing surfaces is provided as a heated smoothing surface. Dryer section according to one of the preceding claims,
characterized in that the shoe roller (14) is insulated from the environment with simultaneous internal cooling, for example by means of the lubricating oil, by means of a hood (62). Dryer section according to one of the preceding claims,
characterized in that the shoe roller (14) provided with a hood (62) is cooled from the inside and / or from the outside with cooling air. Dryer section according to one of the preceding claims,
characterized in that in the web running direction (L) in front of the extended smoothing nip (12) a moistening device is provided for the sectional influencing of the web moisture transversely to the web running direction (L). Dryer section according to one of the preceding claims,
characterized in that the elongated smoothing nip (12) is arranged in a single-row drying group. Dryer section according to one of claims 1 to 10,
characterized in that the elongated smoothing nip (12) is arranged in a two-row drying group. Device for smoothing a material web (22), in particular Paper or cardboard web, especially for use in a Dryer section (10) according to one of the preceding claims, with a smoothing nip (12) extended in the direction of web travel (L), which two opposing pressing surfaces are formed, at least one of which is formed by a shoe roller (14) and at least one of which is heated, preferably one of the both pressing surfaces by a shoe roller (14) and the other is formed by a drying cylinder (18). Device according to claim 13,
characterized in that at least one of the two pressing surfaces is provided as a heated smoothing surface. Device according to claim 13 or 14,
characterized in that the drying cylinder (18) has an increased bending moment compared to a conventional drying cylinder. Device according to one of the preceding claims,
characterized in that the drying cylinder (18) has an outer diameter> 1.5 m, in particular> 1.8 m, in particular 2 m and preferably> 2.4 m and / or a ribbed inner circumferential surface to increase the bending moment. Device according to one of the preceding claims,
characterized in that the drying cylinder (18) is controlled by deflection. Device according to one of the preceding claims,
characterized in that at least one of the two pressing surfaces is heated and has a surface temperature> 40 ° C, preferably> 60 ° C. Device according to one of the preceding claims,
characterized in that the smoothing nip (12) is arranged within a sieve loop. Device according to one of the preceding claims,
characterized in that the flexible jacket (44) of the shoe roller (14) is temperature-resistant up to approximately 120 ° C. and preferably consists of a correspondingly thermally resilient plastic. Device according to claim 20,
characterized in that the flexible jacket (44) of the shoe roller (14) consists of elastomeric material on a polymer basis, for example of polyurethane. Device according to claim 21,
characterized in that the sheath reinforcement consists of elastomeric material whose modulus of elasticity is greater than the modulus of elasticity of the elastomeric sheath material. Device according to one of the preceding claims,
characterized in that the oil used in the shoe roller (14) for lubrication is temperature-resistant up to 120 ° C. Device according to claim 23,
characterized in that the oil and the elastomeric jacket material are coordinated. Device according to one of the preceding claims,
characterized in that the outer diameter of the jacket (44) of the shoe roller (14) is ≤ 1.8 m. Device according to one of the preceding claims,
characterized in that one of the two pressing surfaces is formed by a shoe roller (14) and the other by a drying cylinder (18) and in that the outside diameter of the shoe roller (14) is less than or equal to the outside diameter of the drying cylinder (18). Device according to one of the preceding claims,
characterized in that the shoe roller (14) comprises a center-fixed shoe (38). Device according to one of the preceding claims,
characterized in that the shoe roller (14) comprises a shoe (38) cooled by the relevant lubricating oil. Device according to one of the preceding claims,
characterized in that the shoe roller (14) is provided with means for eliminating the friction occurring as a result of thermal expansion between the shoe (38) and the associated pressing unit (48). Device according to one of the preceding claims,
characterized in that the shoe (38) of the shoe roller (14) can be acted upon sectionally in the transverse direction. Device according to one of the preceding claims,
characterized in that the shoe roller (14) is insulated from the environment with simultaneous internal cooling, for example by means of the lubricating oil, by means of a hood (62). Device according to one of the preceding claims,
characterized in that the shoe roller (14) , which is preferably provided with a hood (62), is cooled with cooling air from the inside and / or from the outside. Device according to one of the preceding claims,
characterized in that the shoe roller (14) is associated with a hood (62) which can be opened upwards and to the sides at least to such an extent that the opening that is formed is at least as large as the outside diameter of the shoe roller (14) and preferably around that Is 1.5 times to 2 times larger than the outside diameter of the shoe roller (14). Device according to one of the preceding claims,
characterized in that the edge regions of the two press surfaces not covered by the material web (22) are at a distance (d) from one another, particularly in the plane of the smoothing nip. Device according to one of the preceding claims,
characterized in that the drying cylinder (18) is conically shaped at the edges and / or the stroke (h) of the shoe (38) assigned to the shoe roller (14) is dimensioned such that the outer edges (42) of the circumferential one Shoe roll jacket (44) results in a distance (d) to the opposite pressing surface which is> 5 mm, in particular> 8 mm and preferably> 12 mm. Device according to one of the preceding claims,
characterized in that the drying cylinder (18) is designed stepped. Method for combined drying and smoothing of a material web (122), in particular paper or cardboard web, in a dryer section (110), in which the material web (122) is first dried to a predeterminable dry content> 60%, in particular> 65% and preferably> 70%, the material web (122) having this predeterminable dry content is guided through a smoothing nip (112) which is elongated in the web running direction (L) and is formed between two opposing pressing surfaces, at least one of which is formed by a circumferential band (144) and at least one of which is heated, the pressing time> 0.8 ms resulting in the extended smoothing nip (112) is selected and the material web (122) is further dried after the smoothing nip (112). A method according to claim 37,
characterized in that at least one of the two pressing surfaces is formed by a shoe unit (114). A method according to claim 38,
characterized in that a shoe roller (114) is used as the shoe unit, through whose jacket (144) the relevant circumferential band is formed. Method according to one of the preceding claims,
characterized in that for at least one of the two pressing surfaces R _a (mean roughness) is <4 µm and preferably <3 µm. Method according to one of the preceding claims,
characterized in that the two press surfaces have a different smoothness. Method according to one of claims 37 to 40,
characterized in that the two press surfaces have the same smoothness. Method according to one of the preceding claims,
characterized in that at least one of the two pressing surfaces is provided as a heated smoothing surface. Method according to one of the preceding claims,
characterized in that, in the web running direction (L), a moistening device is used in front of the extended smoothing nip (112) for the sectional influencing of the web moisture transversely to the web running direction (L). Method according to one of the preceding claims,
characterized in that the elongated smoothing nip (112) is provided in a single-row dryer section (110) or dryer group. Method according to one of claims 37 to 44,
characterized in that the elongated smoothing nip (112) is provided in a two-row dryer section (110) or dryer group. Device for smoothing a material web (122), in particular Paper or cardboard web, in particular to carry out the Method according to one of the preceding claims, with a in the web running direction (L) elongated smoothing nip (112) between two opposing pressing surfaces is formed by at least one of which is formed by a circumferential band (144) and at least one of which is heated. The device of claim 47,
characterized in that at least one of the two pressing surfaces is formed by a shoe unit (114). Device according to claim 48,
characterized in that a shoe roller (114) is provided as the shoe unit, through whose jacket (144) the relevant circumferential band is formed. Device according to one of the preceding claims,
characterized in that for at least one of the two pressing surfaces R _a (mean roughness) is <4 µm and preferably <3 µm. Device according to one of the preceding claims,
characterized in that the two press surfaces have a different smoothness. Device according to one of claims 47 to 50,
characterized in that the two press surfaces have the same smoothness. Device according to one of the preceding claims,
characterized in that at least one of the two pressing surfaces is provided as a heated smoothing surface. Device according to one of the preceding claims,
characterized in that, in the web running direction (L), a moistening device is provided in front of the extended smoothing nip (112) for sectionally influencing the web moisture transversely to the web running direction (L). Device according to one of the preceding claims,
characterized in that one of the two pressing surfaces is formed by a circumferential belt (144) or a shoe unit (114) and the other by a drying cylinder (118). Apparatus according to claim 55,
characterized in that the drying cylinder (118) has an increased bending moment compared to a conventional drying cylinder. Device according to claim 55 or 56,
characterized in that the drying cylinder to increase the bending moment has an outer diameter> 1.5 m, in particular> 1.8 m and preferably> 2 m and / or a ribbed inner peripheral surface. Device according to one of the preceding claims,
characterized in that the drying cylinder (118) is controlled by deflection. Device according to one of the preceding claims,
characterized in that at least one of the two press surfaces is heated and has a surface temperature (T)> 40 ° C, preferably> 60 ° C. Device according to one of the preceding claims,
characterized in that the web speed is> 450 m / min and preferably> 1200 m / min. Device according to one of the preceding claims,
characterized in that the web dwell time in the smoothing nip is> 0.8 msec, in particular> 2 msec and preferably> 4 msec and / or the shoe length measured in the web running direction is> 30 mm and preferably> 60 mm. Device according to one of the preceding claims,
characterized in that the smoothing nip (112) is arranged within a sieve loop. Device according to one of the preceding claims,
characterized in that at least one of the two pressing surfaces is formed by a circumferential band (144) which is temperature-resistant up to approximately 120 ° C, in particular assigned to a shoe unit (114), the band (144) preferably consisting of a correspondingly thermally resilient plastic. Device according to one of the preceding claims,
characterized in that the circumferential band (144) consists of elastomeric material on a polymer basis, for example of polyurethane. An apparatus according to claim 64,
characterized in that the band reinforcement consists of elastomeric material whose modulus of elasticity is greater than the modulus of elasticity of the elastomeric band material. Device according to one of the preceding claims,
characterized in that the oil used for lubrication in the respective shoe unit (114) is temperature-resistant up to 120 ° C. Device according to claim 66,
characterized in that the oil and the elastomeric band material are coordinated. Device according to one of the preceding claims,
characterized in that the circumferential belt (144) is formed by the jacket of a shoe roller (114), the outer diameter of which is ≤ 1.8 m. Device according to one of the preceding claims,
characterized in that one of the two pressing surfaces is formed by a shoe roller (114) and the other by a drying cylinder (118) and in that the outside diameter of the shoe roller (114) is less than or equal to the outside diameter of the drying cylinder (118). Device according to one of the preceding claims,
characterized in that the shoe unit (114) comprises a center-fixed shoe (138). Device according to one of the preceding claims,
characterized in that the shoe unit (114) comprises a shoe (138) cooled by the relevant lubricating oil. Device according to one of the preceding claims,
characterized in that the shoe unit (114) is provided with means for eliminating the friction occurring as a result of thermal expansion between the shoe (138) and the associated pressing unit. Device according to one of the preceding claims,
characterized in that the shoe unit (114) comprises a shoe (138) sectioned in the transverse direction, by means of which the smoothness in the transverse direction can be influenced in sections. Device according to one of the preceding claims,
characterized in that the shoe unit (114) is insulated from the environment with simultaneous internal cooling, for example by means of the lubricating oil through a hood (162). Device according to one of the preceding claims,
characterized in that the shoe unit (114) provided with a hood (162) is cooled from the inside and / or from the outside with cooling air. Device according to one of the preceding claims,
characterized in that the edge regions (140) of the two pressing surfaces not covered by the material web (122) are at a distance (d) from one another, in particular in the plane of the smoothing nip. Device according to one of the preceding claims,
characterized in that the drying cylinder (118) is conically shaped at the edges (140) and / or the stroke (h) of the shoe (138) associated with the shoe unit (114) is dimensioned such that on the outer edges (142 ) of the circumferential band (144) results in a distance (d) to the opposite pressing surface which is> 5 mm, in particular> 8 mm and preferably> 12 mm. Device according to one of the preceding claims,
characterized in that the drying cylinder (118) is designed stepped. Device according to one of the preceding claims,
characterized in that the drying or smoothing cylinder (118) is heated from the outside, for example electrically, by steam and / or the like. Device according to one of the preceding claims,
characterized in that the drying or smoothing cylinder (118), viewed in the transverse direction, can be sectionally heated and the sectional moisture of the material web can be influenced accordingly, so that the smoothing cross profile can be controlled and / or regulated accordingly. Device according to one of the preceding claims,
characterized in that the shoe roller (114) is associated with a hood (162) which can be opened upwards and to the sides at least to such an extent that the opening that is formed is at least as large as the outside diameter of the shoe roller (114) and preferably around that Is dimensioned 1.5 times to 2 times larger than the outside diameter of the shoe roller (114). Dryer section (110) of a machine for producing a material web (122), in particular paper or cardboard web, with a smoothing device according to one of the preceding claims. Dryer section according to one of the preceding claims,
characterized in that at least 70% and preferably at least 90% of the outer diameter of the shoe rollers lie above the machine base (116). Dryer section according to one of the preceding claims,
characterized in that the shoe roller (114) lies completely above the machine base (116). Dryer section according to one of the preceding claims,
characterized in that spacers can be used between the bearing of the shoe unit (114) and a bearing block and / or that cantilever elements can be used.

Images