Device for Supporting a Wire, Felt or Paper Web in a Paper Production Plant

Abstract

A device for supporting a wire or felt in a paper production plant or the paper web produced in the plant. The supporting device includes at least one rotatably mounted supporting roll or the like. The at least one supporting roll or the like is mounted in a bearing shell and, on the side facing away from the wire, the felt or the paper web, can have applied to it a medium capable of flowing, specifically a liquid or a gas, by which means it is kept at a distance from the bearing surface.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. § 119, of Austrian applications A 1924/2006, filed Nov. 21, 2006 and A 495/2007, filed Mar. 29, 2007; the prior applications are herewith incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a device for supporting a wire or felt in a paper production plant or the paper web produced in the plant. The supporting device has a rotatably mounted supporting roll or the like.

In paper production plants, there are at least one wire and at least one felt adjoining the latter in the direction of movement, the two being moved in the plants at high speeds. At the start of its movement path, a paper stock is sprayed onto the wire. Along the movement path of the wire, the liquid contained in the paper stock is led away through the wire, in particular sucked away. The web of paper produced as a result is then transferred to the felt, on which it is dried. The paper web is then detached from the felt and processed further, in particular dried further and rolled.

Wires, felts and paper webs in such paper production plants have widths of up to 12 m, which are moved along the plant at speeds of about 30 m/sec.

The wires and felts located in the plants, and also the paper webs, can be guided during their movement in the plant on supporting rolls, which extend over the entire width of the plant and which are mounted at their two ends. Because of the great length of the supporting rolls and because of the fact that the wires, felts or paper webs bear on these supporting rolls with high pressure, the latter have to be formed with large diameters, which necessitates high constructional expenditure. If, in addition, suction devices are assigned to the wire or felt, supporting rolls of this type cannot be used, however, since the interspace located between them, by which the suction channel is delimited, is so small in relation to that area which is subjected to the suction action that, as a result, no suction action meeting the requirements is achieved.

For this reason, it is not possible to support by means of rolls of this type such regions of the wire or of the felt in which suction devices are arranged.

In order to avoid the disadvantages adhering to the known supporting rolls, in order to support the wires or the felts, it is moreover known to provide supporting strips extending over the width of these wires or felts, which are provided with a wearing layer formed by plates of a ceramic material on their side assigned to the wires or felts. Supporting strips of this type are advantageous inasmuch as, with small dimensions, they exhibit high strength or rigidity, since they can be arranged beside one another at any desired small distances, since suction channels meeting the requirements can be provided between them and since, additionally, they also serve as wiping strips for the liquid reaching the underside of the wire.

Wiping strips of this type are disadvantageous, however, since they are very expensive to produce because of the formation using plates of a ceramic material and since very high frictional forces occur between them and the wires or felts resting on them. As a result of these high frictional forces, firstly a high drive output is required for the movement of the wires or the felts. Secondly, because of these frictional forces, very high thermal loadings and thermal stresses caused by these occur in the plates of a ceramic material, as a result of which the latter can fracture, whereupon they have to be replaced. In addition, both the plates of a ceramic material and the wires and the felts moving over these supporting strips are subjected to very high wear.

BRIEF SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a supporting device for a wire, a felt, or a web in a paper-production facility which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provides for a device that supports at least one wire, at least one felt, or the web of paper and which avoids the disadvantages adhering to the prior art supporting roll.

With the foregoing and other objects in view there is provided, in accordance with the invention, a supporting device in a paper production plant, for supporting a wire, a felt, or a paper web produced in the paper production plant. The supporting device comprises:

a bearing shell having a bearing surface;

at least one supporting roll rotatably mounted in the bearing shell;

the bearing shell being configured for subjecting the supporting roll, on a side thereof facing away from the wire, the felt, or the paper web, to a fluidic medium (i.e., a flowable medium such as water or compressed air) for spacing said supporting roll a distance from the bearing surface.

In other words, the objects of the invention are achieved in that the at least one supporting roll or the like is mounted in a bearing shell and, on the side facing away from the wire, felt or the paper web, can have applied to it a medium capable of flowing, specifically a liquid or a gas, by which means it is kept at a distance from the bearing surface.

Preferably, at least one channel for the supply of the medium capable of flowing opens into the bearing shell. In this case, the at least one channel for the supply of the medium capable of flowing can be constructed with a nozzle-like narrowing and the at least one opening provided in the bearing shell for the medium capable of flowing can be constructed with a widened region, in particular with a dome or with a slot. In addition, a valve, in particular a non-return or check valve, can be located in the at least one supply channel for the medium.

According to a preferred embodiment, the at least one supporting roll can also have a medium capable of flowing applied to its end faces. Furthermore, the at least one supporting roll or the like is at least partly embraced by a cover over which the at least one supporting roll or the like projects in the position of the latter in which medium is applied to it. In this case, as seen in the axial direction, in each case a cover can also be provided on both sides of the at least one supporting roll or the like.

According to a further preferred embodiment, a plurality of supporting rolls, supporting rollers or supporting balls is provided, which are mounted in at least one bearing shell and which are located beside one another and possibly also one after another in the direction of movement of the wire, of the felt or of the web of paper. In this case, at least some of the supporting rolls, supporting rollers, supporting balls or the like can be located on a common carrier for the bearing shells.

According to a further preferred embodiment, supporting rolls or the like can also be provided on both sides of the wire, of the felt or of the web of paper, suction channels, which are connected to a suction device, being located between two supporting rolls or the like located beside each other.

In order to be able to perform very effective cleaning of a felt, the rolls or the like which are located on both sides of the felt and which extend transversely with respect to the felt are furthermore preferably offset in relation to one another in the longitudinal direction of the felt, a supporting roll or the like arranged on one side projecting into the space found between two supporting rolls or the like arranged on the other side, which means that the felt is moved in a wavy course between the mutually opposite supporting rolls or the like. In this case, a spraying device is assigned to the felt.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in device for supporting a wire, felt or paper web in a paper production plant, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a sectional view of a first embodiment of a device according to the invention in a first implementation, specifically for supporting a wire;

FIG. 2 is a sectional view of a second embodiment of a device according to the invention;

FIG. 3 is a sectional view of a second implementation of a device according to the invention;

FIG. 4 is a side view of a third implementation of a device according to the invention;

FIGS. 4A to 4D are side views showing four different further embodiments of a device according to the invention; and

FIG. 5 is a front view of a fourth implementation of a device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a wire 1 in a paper production plant, which is supported by a supporting roll 2. The supporting roll 2 is mounted in a bearing shell 3. The bearing shell 3 is constructed with an approximately semi-cylindrical bearing surface and with flat end faces at the ends. In addition, the bearing shell 3 is constructed with three channels or conduits 4 for the supply of a fluidic medium, i.e., a flowable medium, such as water or compressed air. The channels open in the bearing surface. In addition, the end faces are also constructed with openings, to which a medium capable of flowing is led. In this case, at their ends facing the openings 5, the supply channels 4 are each constructed with a taper 6, by means of which the entry of contaminants into the channels 4 is prevented. In order to ensure a uniform feed flow of the medium to the supporting roll 2, the openings 5 of the channels 4 are also in each case constructed with a widening. By this means, the most uniform loading of the supporting roll 2 over its entire region located in the bearing shell 3 is achieved. In addition, check valves or non-return valves are in each case provided in the supply channels.

As a result of the application of a medium to the supporting roll 2, the latter is raised in the bearing shell 3 in the direction of the arrow A, by which means it is held at a distance with respect to the bearing surface and also with respect to the end faces, so that it can be rotated virtually without friction in the bearing shell 3.

The supporting roll 2 can also be used in the same way as a rest for a felt or for the web of paper produced in the plant.

Because of the fact that the supporting roll 2 is mounted in the bearing shell 3 over its entire length, it can be constructed with a relatively small diameter irrespective of its length without its serviceability being reduced as a result. In this regard, it is pointed out that the supporting roll 2 can extend over the entire width of the wire 1, of the felt or of the web of paper, and that a plurality of coaxial supporting rolls or other supporting elements can be provided over the width of the wire, felt or web.

FIG. 2 illustrates a second embodiment of a device according to the invention, in which the supporting roll 2 is constructed with covers 7 arranged at the sides, which are bent over toward the supporting roll 2 in the upper region, which means that lifting of the supporting roll 2 beyond a predefined extent is limited. The covers 7 are in this case fixed to the bearing shell 3 by means of screws 8. Furthermore, the bearing shell 3 is fixed to a plate-like carrier 10, which is pierced by the three supply channels 4 and in whose lower region there is a recess 11, from which the three supply channels 4 originate.

By using FIG. 3, the use of such a supporting roll 2 as a breaker roll in a paper production plant will be explained. Breaker rolls are used to align the web of paper 13 in a cross-cutter. In this case, the web of paper 13 is led over a first deflection roll 14, then over the supporting roll 2 and also over a second deflection roll 15. In order to be able to adjust the extent of the bending of the web of paper 13, the carrier 10 can be displaced vertically.

In FIG. 4, three supporting rolls 2 arranged beside one another in the direction of movement of the wire 1 or the felt are illustrated, between which there are suction channels 16. In this case, the carriers 10 are fixed by means of screws 10a to a support 17, which is constructed with suction channels 16a connected to a suction device. By means of this arrangement, a suction force can be applied to the wire 1 or the felt between the supporting rolls 2.

Three further embodiments will be explained with reference to FIGS. 4A to 4D:

In the embodiment illustrated in FIG. 4A, the supporting roll 2 extends over the entire width of the paper production plant.

In the embodiment illustrated in FIG. 4B, instead of a single supporting roll, four coaxial supporting rolls 21 arranged beside one another are provided, on which the wire or the felt rests.

In the embodiment illustrated in FIG. 4C, the individual supporting rolls 21a are crowned.

In the fourth embodiment, illustrated in FIG. 4D, instead of supporting rolls arranged beside one another, a group of supporting balls 21b arranged beside one another and possibly after one another in the direction of movement are provided, which extend over the width of the wire, felt or web carried by these.

The supporting rolls 21, the supporting rolls 21a and the supporting balls 21b can be located beside one another and additionally also one after another in the direction of movement of the wire 1 or felt.

All the supporting elements are assigned side covers 7. The arrangement of individual supporting rolls or the like located beside one another is advantageous since, as a result, a suction action can also be exerted on the wire or the felt between these individual supporting elements.

A supporting device according to the invention is thus advantageous since, for the movement of the at least one wire or the at least one felt, it requires only low drive outputs, since the wear of the supporting elements, on one hand, and of the wire or the felt is low and since, between the supporting elements, there is sufficient space for suction channels in order to be able to apply to the wire or to the felt appropriate suction forces meeting the requirements.

FIG. 5A illustrates a further development of the device according to FIG. 4, in which, on both sides of a felt 1a, a plurality of such suction rolls 2 is provided, between which there are suction channels 16 connected to a suction device. In this case, the supporting rolls 2 located on one side of the felt 1a in each case are offset with respect to the supporting rolls 2 located on the other side of the felt 1a in the longitudinal direction of the felt 1a, and they project into the spaces between the supporting rolls 2 provided on the other side of the felt 1a, which means that the felt 1a is moved in a wavy course. The supporting rolls 2 located on the two sides of the felt 1a can preferably be displaced with respect to each other, which means that the wavy course of the felt 1a can be adjusted.

For the cleaning of a felt 1a, a spray pipe 9 oriented transversely with respect to the movement path of the felt 1a is provided, by means of which a cleaning liquid 9a can be applied to the felt 1a. By means of such an arrangement, very effective cleaning of the felt 1a is achieved.

Claims

1. A supporting device in a paper production plant, for supporting a wire, a felt, or a paper web produced in the paper production plant, the supporting device comprising: a bearing shell having a bearing surface;at least one supporting roll rotatably mounted in said bearing shell;said bearing shell being configured for subjecting said supporting roll, on a side thereof facing away from the wire, the felt, or the paper web, to a fluidic medium for spacing said supporting roll a distance from said bearing surface.

2. The device according to claim 1, wherein said fluidic medium is a medium capable of flowing selected from the group consisting of a liquid and a gas.

3. The device according to claim 1, wherein at least one channel for supplying the fluidic medium opens into said bearing shell.

4. The device according to claim 3, wherein said at least one channel is constructed with a nozzle-type narrowing.

5. The device according to claim 1, wherein said bearing shell is formed with at least one opening through which the fluidic medium flows, and said opening is formed with a widened region.

6. The device according to claim 5, wherein said widened region in the bearing shell is a dome or a slot.

7. The device according to claim 1, which comprises a valve disposed in at least one supply channel for the fluidic medium.

8. The device according to claim 7, wherein said valve is a check valve.

9. The device according to claim 1, wherein said at least one supporting roll is disposed to have a fluidic medium applied to end faces thereof.

10. The device according to claim 1, which comprises a cover at least partly embracing the supporting roll, and wherein said supporting roll projects out of said cover in a position in which the fluidic medium is applied to said supporting roll.

11. The device according to claim 10, wherein, as seen in an axial direction, in each case a cover is provided on the two sides of said at least one supporting roll.

12. The device according to claim 1, wherein said at least one supporting roll is one of a plurality of supporting rolls, supporting rollers, or supporting balls, mounted in at least one said bearing shell and disposed beside one another.

13. The device according to claim 12, wherein said plurality of supporting rolls, supporting rollers, or supporting balls are disposed one after another in a direction of movement of the wire, the felt, or the web of paper.

14. The device according to claim 12, wherein at least some of said supporting rolls, supporting rollers, or supporting balls are supported on a common carrier for said bearing shells.

15. The device according to claim 12, wherein at least one supporting roll is provided on each side of the wire, the felt, or the web of paper.

16. The device according to claim 12, which comprises a suction device and one or more suction channels issuing at a location between two said supporting rolls.

17. The device according to claim 15, wherein said supporting rolls on opposite sides of the felt and extending transversely with respect to the felt are offset in relation to one another in a longitudinal direction of the felt, a respective said supporting roll arranged on one side projecting into a space between two respective supporting rolls arranged on the opposite side, to define a wavy course of the felt between the mutually opposite supporting rolls.

18. The device according to claim 17, which comprises a spraying device disposed to spray the felt.