EP1712500A2 - Web guiding element - Google Patents

Abstract

The element subjects compressed gas (6) over the entire width of the web (5), and which has a coat (2) with a course conducting surface (4) and a porous, gas-permeable layer (3). The gas penetrates the coat in an operating phase, forming an operating and or a work area (A) between the web conducting surface and the fibrous material course. The porous layer forms a resistance for the coat flowing by the compressed gas and the web turns around its own longitudinal axis (8) and or a parallel axis (8a), so that the coat with the course conducting surface is shiftable into a cleaning range (R).

Description

The invention relates to a web guide for non-contact guiding and / or deflecting a running paper board or other fibrous web, which is acted upon with compressed gas and extends substantially over the entire width of the fibrous web.
The web element has a jacket with a web guide surface and at least one porous, gas-permeable layer. The compressed gas penetrates the jacket in an operating phase in order to form an air film in an operating or working area between the web guide surface and the moving fibrous web.

Such a web guide is in the DE-A1 10322519 and is sold by the Applicant Company under the name "TopTurn".

Due to the fact that the web guiding element has an outer casing made of porous material, the web guiding surface during operation, rather than smooth surfaces, tends to foul, so that the tiny pores clog up and their function, which consists in the gas or air permeability, no longer exists does justice. As a rule, the very high-speed fibrous web can no longer be properly guided.

The invention is therefore based on the object to develop a web guide, with which the disadvantages mentioned are avoidable.

The object of the invention is achieved by the features specified in the characterizing part of claim 1.
Accordingly, it is provided that the porous layer forms a resistance for the pressure gas flowing through the jacket and the web-guiding element is rotatable about its own longitudinal axis or an axis parallel to it, so that the jacket with the web-guiding surface passes from the working area into a cleaning area.

Due to the fact that the web guiding element according to the invention with its porous jacket layer forms a resistance for the pressurized gas flowing through the jacket, this is particularly prone to contamination and the need for cleaning.
In the context of the invention, the web guiding element can now be rotated in a simple manner about its own longitudinal axis or an axis parallel to it, which runs parallel to the width of the fibrous web to be guided. The jacket with the Bahnleitfläche is thereby shifted from the work area in a cleaning area, wherein the Bahnleitfläche, which was just the active functional area in the leadership and / or deflection of the fibrous web and thereby was contaminated as mentioned, can be cleaned. The advantage of the invention is therefore that the functionality of the web guide is fully restored, without the web guide or parts thereof from the machine in which the fibrous web runs, must be removed. This saves time and money.

In certain cases, it is even possible to clean this jacket and the web guide during the operating phase. This applies to the preferred case where the web guide is larger than the work area. If, by contrast, the web guiding element is designed according to the width of the working area, cleaning can only take place outside the operating phase.

It is possible to rotate the web guide only when needed (discontinuous). But it is also a continuous turning further possible. The web guiding element (TopTurn) is constantly supplied with gas, in particular conditioned air, so that in this way blockages of the functional layer - ie the at least one layer of the jacket of the web guiding element - is effectively prevented.

An expedient embodiment of the Bahnleitelementes may consist in that it is made as a rotationally symmetrical body with a circular cylindrical cross-section. However, embodiments of the cross sections in the form of circular segments or circular cross sections with segmental cutouts or other geometries are also conceivable.

In addition, the invention provides that the direction of rotation of the rotatable in the cleaning position Bahnleitelementes is arbitrary.
Thus, a rotation in the web running direction may be useful or a rotation against the web running direction.
During the rotation in the web running direction, it is advantageous to have a longer drying time after cleaning (if it is carried out with liquid), before the cleaned area of the web guide surface comes close to the path running over it.
A choice of the direction of rotation against the web running direction is advantageous if already present larger contaminants. This contamination can be transported immediately from the work area in the direction of the cleaning area without disturbing the drainage zone of the work area.

It is expedient if the rotational speed of the web guiding element is set slower, in particular substantially slower, than the speed of the fibrous web running in the operating phase. As a result, the cleaning process is correspondingly longer and the quality of cleaning can be improved.

The web guiding element can be suitably configured by forming or forming a rotating jacket or sections of the jacket, the outer surface of which, as stated, forms the web guiding surface and a fixed, sealed-off inner chamber serving to supply the working area, which is similar to one known Saugwalze- has. The rest of the circumference does not need to be supplied with compressed air. With a wrap around the fibrous web of about 90 ° and effective only in this area pressure chamber leads to a saving of running costs of about 60%.

In certain cases, it may be useful if the cleaning area following the direction of rotation of the web guiding element, further away from the work area. This embodiment is advantageous if the cleaning device for reasons of space, for example only on the diametrically opposite side of the work area (for example, circular shape of the Bahnleitelementes) can be accommodated.

A further advantageous solution is that the interior of the Bahnleitelementes is divisible into a plurality of inner chambers, which can be acted upon either with the same or with different pressure or partially unpressurized. Although the design effort for additional partitions and seals is slightly higher, but the advantage of pressure profiling, i. The pressurization where it is needed outweighs it.

The inner chambers are designed so that they do not rotate, but still can be adjusted in their relative position and / or size.

A further advantageous solution may be that the individual chambers in the axial longitudinal direction, i. Seen in the width direction of the machine or the fibrous web, can be acted upon with different pressures. This can be specifically targeted to specific areas influence.

For cleaning agents such as brushes or nozzles and / or compressed air and / or water, which is displaceable with cleaning agents or ultrasound or laser can be used. Their selection depends on how strong and what consistency the contaminants to be removed are.

The cleaning can be done manually as well as automated. In the case of the automated cleaning to be performed, a sensor for monitoring the polluting areas and a command and control unit for triggering the cleaning must be provided.

The invention will be explained in more detail below with reference to exemplary embodiments:

In a schematic representation:

FIGS. 1 to 4:
Various variants of a web guide element according to the invention in cross section

In the figures, the same components are in principle provided with the same reference numerals.

FIG. 1 shows a web guiding element 1 according to the invention.
The web guiding element 1 here has a hollow cylindrical cross section and a jacket 2, which consists of at least two layers. One layer should be referred to as inner shell 2a and another layer consists of a gas-permeable, porous layer 3. The surface of the shell 2 forms a Bahnleitfläche 4 for a non-contact guided and here also deflected, running in the direction L paper carton or other 5. The web guiding element 1 extends essentially over the entire width of the fibrous web 5. In the chosen example, the porous layer 3 is arranged on the outside. Although this porous material is gas-permeable due to its fine pores, its resistance to the intended gas flow is opposed This ensures that in the operating phase, the fibrous web 5 is exposed to any impingement air flow (as in known Airturns) and thereby blisters or wrinkles of the fibrous web 5 are avoided.
In other embodiments, the structure of the shell 2 may also be reversed, ie the inner shell 2a could be made of the porous material and serve the outer layer of stability.

In Figure 1 is in any case shown that the web guide element 1 its interior I with compressed gas 6, that is conditioned (oil and impurities liberated, filtered and dried) compressed air is applied at least in a partial region T _B. This partial area T _B is approximately identical to the looping area of the fibrous web 5, which in the example is approximately 90 °. This results in a so-called working area A of likewise about 90 °, so that the compressed gas 6 flows through the jacket 2 during the operating phase of the web guiding element 1 precisely in this area A. This can be within this work area A between form the Bahnleitfläche 4 and the current fibrous web 5 a supporting air film 7, without the fibrous web 5 bulges undesirable or forms wrinkles.

As shown in FIGS. 1 and 2 , here the web guiding element 1 is manufactured as a rotationally symmetrical body. The web guide is also about its longitudinal axis 8, which is parallel to the width of the fibrous web 5, rotatable. As a result, the web guide surface 4 from the working area A is pivotable downwards into a cleaning area R. The direction of rotation is indicated in Figure 1 with arrow 9 and runs here in with the web running direction. The advantage here is that the drying time after cleaning by means of cleaning agents 10 (see dashed arrows in the area R) is longer before the Bahnleitfläche 4 comes again in the vicinity of the fibrous web 5.

The cleaning area R is therefore provided in order to be able to free the web guiding surface 4 or the jacket 2 having the at least one porous layer 3 from contaminants V which originate from the high-speed fibrous web 5 or other influences. Due to the fact that the jacket 2 is permeable to gas, the minute pores, especially of the positive layer, can become clogged during the operating phase, as a result of which malfunctions may occur.
It is particularly desirable to carry out the cleaning during the operating phase, ie while the fibrous web 5 continues to be guided over the porous web guiding element 1 and thereby passes through the working area. The advantage here is that the machine does not have to be shut down and thus downtimes can be avoided.

Incidentally, the direction of rotation of the rotationally symmetrical web guiding element 1 is freely selectable.
The advantage which arises in the opposite direction of rotation (counterclockwise, counter to the web running direction) is the following: If impurities V occur, the inlet side 11 to the working area A is particularly endangered. The impurities V can be transported away from the working area A immediately, as indicated in FIG. 2 , in the opposite direction of rotation 12 and in the direction of of the cleaning area R promote. The run-off zone 13 of the working area A is not disturbed by this and likewise not the continuing running web side 5a of the fibrous web 5 facing the web guide surface 4.

The rotational speed of the web guiding element 1 is significantly slower than the speed of the fibrous web 5 running over it.

In both Figures 1 and 2 is shown as a variant, a continuous circular rotating jacket 2, the outer surface as I said, consistently forms the Bahnleitfläche 4. However, a variant is also possible, but not shown, in which the outer casing is not continuous and, for example, only partially applied in the axial direction on the inner casing 2a (or vice versa.) Furthermore, the Bahnleitelement 1 can also be designed so that there is no complete circular cross section forms.

In the variants described, the casing 2 rotates about the fixed with compressed gas, ie compressed air acted upon interior I or the pressurized portion T _B , which can also be referred to as blowing zone.
The blowing zone then corresponds to the indicated in Figure 1 and 2 work area A. This offers the advantage that not the entire circumference must be supplied with compressed air, but just the said work area A.

FIG. 1 also shows that the cleaning area R follows the direction of rotation 9 (clockwise) of the web guiding element, directly downstream of the working area A.

FIG. 2 , on the other hand, shows that the cleaning area R is arranged downstream of the working area A, following the direction of rotation 12.

In addition, here is an embodiment variant with independent of the rotation of the shell inner I shown, in which a plurality of chambers 14, 15, 16, 17 exist, either with the same or with different pressure can be acted upon or partially depressurized. The chamber walls are designated here by W. Thus, chamber 15 and 16 and the area A or chamber 17 can be supplied with the same pressure (or even form a single chamber 17), whereas the chamber 14 remains without compressed air supply. In a further alternative, the chamber 14 could be provided with compressed air to prevent contaminants V from penetrating the mantle surface until the portion of the cleaning is reached. A compressed air supply of the chamber 16 may therefore be useful, for example, to ensure better drying of the cleaned shell 2 and the Bahnleitfläche 4, before they get back to the work area A.

In Figure 2 , the feeds for compressed air 6 because of their alternative application for the chambers 14, 15 and 16 are therefore shown by dashed lines.

The inner chambers 14 to 17 should not rotate in the example provided, but are adjustable in their relative position and, if desired, in their size.

The individual chambers 14 to 17 are also seen in the axial longitudinal direction, can be acted upon with different pressures, but this is not shown in Figures 1 and 2.

For manual or automated cleaning are means 10, both brushes and nozzles and / or compressed air and / or water, which is displaceable with cleaning agents or ultrasound or laser devices possible. These agents 10 can be used individually or in combination. In addition, a collecting trough 18 is arranged, which serves to collect and collect or remove the removed impurities.

In Figure 3 , a further, but only roughly indicated variant is shown in which the web guiding element 1 only about the size of the working area A or Umschlingungsbereiches the fibrous web 5 and about a circular sector-shaped Cross section has. The cleaning of the shell 2 can be carried out only outside the operating phase. For this purpose, the web guiding element 1 can be rotated around its own longitudinal axis into a cleaning position R, as shown in dashed lines. The other reference numerals given here correspond to the reference numerals that have been given in the previous figures and will not be explained again.

4 shows a further embodiment of Bahnleitelementes 1. It differs from that shown in Figure 3 only in that it is not rotated about its own longitudinal axis 8 in the cleaning position R, but a parallel axis 8a of a supporting structure 20 on which the Web guiding element is attached.

LIST OF REFERENCE NUMBERS

1

web guide element

2

coat

2a

inner sheath

3

porous layer

4

Bahnleitfläche

5

Fibrous web

5a

facing railway side

6

compressed gas

7

Inflatable Movie

8th

longitudinal axis

8a

parallel axis

9

Arrow for turning sense

10

cleaning supplies

11

supply side

12

opposite direction of rotation

13

outlet side

14-17

chamber

18

drip tray

20

supporting structure

A

Workspace

I

Interior

L

Running direction of the fibrous web

R

cleaning area

T _B

subregion

V

impurities

W

chamber wall

Claims (10)

Web guide for contactless guiding and / or deflecting a running paper, cardboard or other fibrous web, which is acted upon with compressed gas (6) and extends substantially over the entire width of the fibrous web (5) and a jacket (2) with a Bahnleitfläche (4) and at least one porous, gas-permeable layer (3), wherein the compressed gas (6) in an operating phase, the shell (2) penetrates to in an operating or working area (A) between the Bahnleitfläche (4) and the above running fibrous web (5) to form an air film (7),
characterized in that
the porous layer (3) forms a resistance for the compressed gas (6) flowing through the jacket (2) and the web guiding element (1) is rotatable about its own longitudinal axis (8) or an axis (8a) parallel to it, so that the jacket (2) with the web guide surface (4) from the work area (A) in a cleaning area (R) is displaced. Web guiding element according to claim 1,
characterized in that
it is preferably cleanable during the operating phase. Web guiding element according to claim 1 and 2,
characterized in that
whose direction of rotation is freely selectable. Web guiding element according to claim 1 to 3,
characterized in that
whose rotational speed is slower than the speed of the running in the operating phase fibrous web. Web guiding element according to claims 1 to 4,
characterized in that
the jacket (2) is rotatable about the inner jacket (2a). Web guiding element according to claims 1 to 5,
characterized in that
the cleaning area (R) following the direction of rotation, immediately downstream of the working area (A). Web guiding element according to claims 1 to 6,
characterized in that
the cleaning area (R) following the direction of rotation, from the work area (A) is located further away. Web guiding element according to one or more of the preceding claims,
characterized in that
serving the Druckgasbeaufschlagung interior I into a plurality of inner chambers (14, 15, 16, 17) is divisible, which can be acted upon either with the same or with different pressure or partially unpressurized. Web guiding element according to one or more of the preceding claims,
characterized in that
the individual chambers (14, 15, 16, 17) seen in the axial longitudinal direction, can be acted upon with different pressures. Web guiding element according to one or more of the preceding claims,
characterized in that
for its manual or automated cleaning means, such as brushes and nozzles and / or compressed air and / or water, which is displaceable with cleaning agents and / or ultrasound and / or laser are provided.

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