MODULAR STRAND GUIDE ROLLER

Abstract

The invention is based on the object of creating a strand guide roller being configured in a modular manner, which can be retrofitted to different stand casting widths without any substantial effort, and which has a cooling effect starting from the core regions of the roller extending up to the region near the surface thereof, thereby improving the life of the strand guide roller and achieving a comparatively cost-effective maintenance. The problem is solved according to the invention in that a first centrally disposed, axially extending flow channel (11 and a second centrally disposed, axially extending flow channel (12) are present in each roller module (2, 3, 4), that flow channels (15, 16) are disposed in the region near the surface of each roller module (2, 3, 4), and that connecting channels (17) connect the respective flow channels (15) to the first separate flow channel (11), and that connecting channels (18) connect the respective flow channels (16) to the separate second flow channel (12).

Description

The invention concerns a modularly constructed strand guide roller for the strand guide unit of a continuous casting plant in accordance with the features of the preamble of claim 1, a strand guide roller in accordance with the features of claim 13, and a method for operating it in accordance with claim 14.

A strand guide roller is known from EP 1 485 218 B1, which, however, proceeding from the objective of the invention, focuses on a rotary leadthrough for a cooling water inlet and outlet of a support and/or transport roller pivoted at least at the end with journals in bearing blocks, especially in a continuous casting plant. The outer region of the water-cooled support and/or transport roller has axial channels and channels that run into or out of these axial channels and to a central distribution system. The central distribution system consists of a central bore in the support and/or transport roller and of a tubular line arranged therein, which has a central supply channel for the cooling water and with the central bore forms an annular channel for the removal of the cooling water.

The strand guide roller disclosed in the cited document consists of two or more roller segments, each of which is supported at its end. This type of end bearing of the individual roller segments is expensive and entails considerable labor for the assembly and disassembly of the bearing units during maintenance of the strand guide unit.

Furthermore, as a result of this type of end bearing of the roller segments, strand guide units cannot be changed over to other casting machine widths without considerable labor.

WO 2007/121821 A1 discloses a strand guide roller of a strand guide unit that consists of at least two roller sections, on which a strand cast by a continuous casting machine is guided, according to which a plug connection is formed between the two roller segments, and only one bearing is provided, which is designed as an undivided single bearing. Aside from a number of advantages over the cited document, the sole cooling medium flow channel, which runs centrally over essentially the whole width of the strand guide roller, fails to develop a sufficient cooling effect for the strand guide roller. Especially the region of the strand guide roller near the surface does not experience sufficient cooling to reduce the wear of the strand guide roller that results from chemical and mechanical stress. Therefore, the centrally running flow channel serves primarily to cool the inner rings of the bearing in the area of the journal of the strand guide roller or the roller segments.

The internally cooled strand guide roller additionally disclosed by the documents WO 2004/094087 A1 and EP 1 646 463 B1 comprises a central rotatable shaft and several roller shells that have integrated coolant channels and are secured against rotation and supported on the shaft. Practical experience shows that these strand guide rollers with roller shells slipped onto them not only show unsatisfactory cooling of the roller barrels but also an enormously high proportion of sealing elements and thus do not represent a maintenance-friendly and operationally reliable solution.

Therefore, the objective of the invention is to create a modularly constructed strand guide roller which can be changed over to different continuous casting widths without any great effort and which has a cooling effect that extends from the core region to the region near the surface and thus improves the service life of the strand guide roller.

A further objective of the invention is to create a modularly constructed strand guide roller that allows comparatively low-cost maintenance. Yet another objective of the invention is to create a strand guide unit with strand guide rollers that are improved with respect to increased service life and easier maintenance.

In accordance with the invention, the objective is achieved by the features of claim 1 and the features of claims 13 and 14. According to the features of claim 1, the modularly constructed strand guide roller for the strand guide unit of a continuous casting plant comprises

• • at least a first roller module and a second roller module, where the two roller modules are disposed side by side in the axial direction, and the first roller module has a centrally located roller journal at its end face that faces the second roller module,
  • a middle bearing, which is arranged between the first and second roller modules for mounting and supporting the roller journal of the first roller module, where the middle bearing is an undivided single bearing,
  • a plug connection formed between the second roller module and the roller journal for plug connection of the first and second roller modules with each other, and
  • a flow channel that runs centrally in the roller modules for conveying a coolant, such that, in accordance with the invention, the centrally running flow channel consists of a first separate flow channel and a second separate flow channel, and such that
  • the first and second separate flow channels of each roller module are connected by connecting channels with flow channels formed in the region near the surface.

In a further refinement of the invention, the flow channels formed in the region near the surface of each roller module are present in pairs. In this regard, in a first flow channel of the paired flow channels, the coolant flows in the opposite direction from the coolant that flows in the centrally running flow channels, and in a second flow channel of the paired flow channels, the coolant flows in the same direction as the coolant that flows in the centrally running flow channels. An open coolant circulation is thus formed in each roller module. At one end of the paired flow channels, a chamber is formed, which serves to deflect the coolant within the first roller module and the following roller module. The chambers are tightly sealed from the outside with a cover, so that no coolant can escape.

In addition, the first flow channel of each pair of flow channels is connected by a corresponding first connecting channel with the first centrally running flow channel, and the second flow channel of each pair of flow channels is connected by a corresponding second connecting channel with the second centrally running flow channel.

In this regard, the connection is produced, for one thing, in such a way that the first connecting channel connects the supply-side outlet of the first centrally running flow channel with the discharge-side inlet of the respective flow channel of the paired flow channels, and, for another, in such a way that the second connecting channel connects the supply-side outlet of the second respective flow channel of the paired flow channels with the discharge-side inlet of the second centrally running flow channel.

As a result of this type of course of the flow channels within the roller module in accordance with the invention, not only are the core region and the region of the bearing cooled, as is already known from the prior art, but also the region near its surface.

In a further refinement of the invention, when the plug connection between the first and second roller modules has been effected, the second centrally running flow channel of the first roller module and the first centrally running flow channel of the second roller module are connected by a coupling sleeve, so that the coolant can flow from the second centrally running flow channel of the first roller module into the first centrally running flow channel of the second roller module.

The second roller module and each additional roller module of the strand guide roller is, where the totality of the construction of the flow channels and connecting channels is concerned, constructed identically to the first roller module. For example, in the case of a strand guide roller with a first and a second roller module, a first open coolant circulation is joined with a second open coolant circulation to form a common open coolant circulation, such that the first coolant circulation can be connected to a coolant inlet, and the second coolant circulation can be connected to a coolant outlet.

Advantageously, the modularly constructed strand guide roller makes it possible for the first time to construct a strand guide roller for different continuous casting widths, which is adequately cooled both in the core region and in the region near the surface.

Due to the small axial extent of the bearing gaps between the individual roller modules, the advantageous result is obtained that only greatly reduced or minimized bulging of the slab occurs in the regions not supported by the strand guide rollers.

The design of the flow channels in accordance with the invention allows overall improved cooling of the strand guide roller with the result that the service life of the roller is increased and that the spectrum of steel grades that can be cast is expanded.

The provision of detachable covers for the peripheral flow channels or the chambers has the advantage that these would now be accessible and could be cleaned.

With a helical arrangement of the peripheral flow channels, they can be arranged and operated in groups, e.g., as a multiple thread. A first group could then be used for the forward movement of the coolant and a second group for its return movement.

A variable or alternating flow direction of the coolant in adjacent strand guide rollers, adjacent roller segments, or in upper and lower frames of a segment helps to even out the cooling effect on the strand or slab.

Further advantages and features of the present invention are apparent from the dependent claims and the description of a specific embodiment illustrated in the accompanying drawings.

FIG. 1 is a cross-sectional drawing, along sectional line A-A in FIG. 4, of a strand guide roller that consists of three roller modules.

FIG. 2 shows detail “Z” in FIG. 1 with an enlarged view of the flow channels and connecting channels that convey the stream of coolant from the core region to the region near the surface.

FIG. 3 is a cross section of the strand guide roller in an enlarged view along line D-D in FIG. 1.

FIG. 4 is a cross section of the strand guide roller in an enlarged view along line B-B in FIG. 1.

FIG. 5 is a view of the second or middle roller module in direction “A” in FIG. 6.

FIG. 6 shows the second or middle roller module of the strand guide roller in the longitudinal section along line C-C in FIG. 5.

FIG. 7 is a side view of the second or middle roller module of the strand guide roller according to FIG. 6.

The strand guide roller 1 shown in FIG. 1 consists of a first roller module 2, a second roller module 3, and a third roller module 4. All of the roller modules are assembled into a strand guide roller according to the prior-art document WO 2007/121821, specifically, by a first plug connection between the second or middle roller module 3 and the inner roller journal 2.1 of the first roller module 2 and by a second plug connection between the third roller module 4 and the inner roller journal 3.1 of the second or middle roller module 3.

The inner roller journal 2.1 of the first roller module 2 is mounted in an undivided middle bearing 5, and the inner roller journal 3.1 of the second or middle roller module 3 is mounted in an undivided middle bearing 6. Both of the middle bearings 5, 6 are advantageously designed relatively short in their axial extent, which means that the transition region 7 between the roller modules 2, 3 and 3, 4 are likewise designed relatively short, so that advantageously a bulging of the cast metal strand (slab) is minimized or greatly reduced.

The outer roller journal 2.2 of the roller module 2 and the outer roller journal 4.1 of the roller module 4 of the strand guide roller 1 are each mounted in an outer bearing 8 and 9, respectively.

The second or middle roller module 3 is not mounted in the middle bearing 5, and the third roller module 4 is not mounted in the middle bearing 6. A plug connection, for example, is provided as the means of connection between the respective roller modules 2, 3 and 3, 4. In this regard, as is seen best in FIG. 6, the roller modules 3 and 4 have a recess 10 on their end face that faces the first roller module 2 and the second roller module 3, respectively. A component 23, for example, one with an annular design, is inserted into this recess in such a way that it is secured against rotation. An extension 2.1.1 or 3.1.1 of the respective roller journal is machine-faced relative to the roller journal itself and can be connected in a positive-locking way with the component 23. Further details of the positive-locking connection or plug connection will not be discussed here, since these are not objects of the present invention.

As FIG. 1 also shows, each roller module 2, 3, 4 has a first and second centrally running flow channel 11 and 12, respectively. In this regard, the flow channel 11 of the roller module 2 can be connected to a coolant inlet 13, and the flow channel 12 of the roller module 4 can be connected to a coolant outlet 14.

To allow complete cooling of each roller module of the strand guide roller 1, i.e., not only cooling of the core region and bearing region but also cooling of the region near the surface, each of the roller modules has additional flow channels and connecting channels, which, together with the centrally running flow channels 11, 12, form an open coolant circulation in each roller module 2, 3, 4 and, ultimately, in each strand guide roller 1 designed in accordance with the invention.

To this end, as shown in FIG. 2, axially running flow channels 15, 16 are formed in the region near the surface of the outer periphery of each roller module 2, 3, 4 that guides and supports the metal strand. First connecting channels 17 and second connecting channels 18 connect the axially running flow channels 15, 16 with the centrally running flow channels 11, 12 to form an open coolant circulation.

In this regard, the coolant circulation is formed in such a way that, as FIG. 3 shows, the flow channels 15, 16 are arranged in pairs in the region near the surface, and, specifically, are preferably regularly distributed around the periphery, where one of the flow channels of the paired flow channels 15, 16 is connected by the connecting channel 17 with the supply-side outlet 11.1 of the flow channel 11, and the other flow channel of the paired flow channels 15, 16 is connected by the connecting channel 18 with the discharge-side inlet 12.1 of the flow channel 12.

As is best seen in FIG. 2, the paired flowed channels 15, 16 are each sealed at the end, individually or together, by covers 19 and 27 in such a way that these ensure a change in the direction of flow of the coolant in conjunction with corresponding chambers 20 formed at the end face in the given roller module.

A special advantage of a coolant circulation of this type is that the connecting channels 17, 18 are placed in each roller module 2, 3, 4 at the journal end in the direction of the coolant inlet 13, and thus the peripheral surface of each roller module is free of any machining process for forming connecting channels with necessarily present sealing elements. In the mounted state of the strand guide roller 1, each second centrally running flow channel 12 of the roller modules 2 and 3 is connected by a coupling sleeve 21 with the respective first centrally running flow channel 11 of the roller module 3 and 4. As a result, the open coolant circulation of each roller module is brought together to form an open coolant circulation of the strand guide roller 1.

To provide better understanding of the coolant circulation within the strand guide roller 1, the direction of flow of the coolant 22 from the coolant inlet 13 to the coolant outlet 14 is indicated by directional arrows.

The coolant 22 flowing into the flow channel 11 of the roller module 2 flows at the end of the flow channel 11 into the connecting channel 17 and enters flow channel 15 of the paired flow channels 15, 16. At the end of flow channel 15, the coolant 22 is carried into flow channel 16 of the paired flow channels 15, 16 and enters the discharge-side inlet 12.1 of the second centrally running flow channel 12, from which it is carried into the first centrally running flow channel 11 of the roller module 3 via the coupling sleeve 21.

The further course of the flow of the coolant 22 in the roller modules 3 and 4 occurs analogously to the course of the flow described for roller module 2, so that there is no need to provide further details here.

FIG. 2 is an enlarged detail view of section “Z” in FIG. 1 and shows the relevant design of the flow channels and connecting channels of roller module 2 and the direction of flow of the coolant 2. The same parts in FIGS. 1 and 2 are identified by the same reference numbers.

FIG. 3 is a cross-sectional view along line D-D in FIG. 1. It shows the region of the plug connection between roller module 2 and roller module 3 as well as the axially running flow channels 15 and 16, which are arranged in pairs in the region of roller module 3 near the surface, with the cover 27 removed. Each pair of flow channels 15, 16 comprises a flow channel 15 with coolant 22 flowing in and a flow channel 16 with coolant 22 flowing out. The flow channels in a paired set of flow channels 15, 16 are connected with each other by a chamber 20 placed in the roller module. In addition, the drawing shows the second centrally running flow channel 12 in the roller journal 2.1 of the roller module 2.

FIG. 4 is a cross-sectional view of roller module 3 along line B-B in FIG. 1 with the paired flow channels 15 and 16 arranged near the surface and with the centrally arranged, first flow channel 11.

FIG. 5 is a side view of roller module 3 shown in FIG. 6. The axially running flow channels 15, 16, which are arranged in pairs in the region of the roller module 3 that is near the surface, are tightly sealed at the end with a preferably detachable individual or common cover 27. The drawing also shows the centrally running flow channel 11, 12 of the roller module 3.

The flow channel 11 is connected with the respective flow channels 15 of the paired flow channels 15, 16 by the connecting channels 17, which run at an acute angle, while the flow channel 12 is connected with the respective flow channels 16 of the paired flow channels 15, 16 by the connecting channels 18, which run at an acute angle.

FIG. 6 shows a longitudinal section along line C-C in FIG. 5. The roller module 3 and roller journal 3.1 are shown once again in a clearly understandable way. Also shown is the preferably polygonally designed extension 3.1.1 of the roller journal 3.1.

In addition to the arrangement of the flow channels and connecting channels that has already been described in detail above, the roller module 3 has a recess 10, which is located on the end face that faces away from the roller journal 3.1. The recess 10 holds an annular component 23, which is secured against rotation by suitable securing means 24, for example, dowel pins. In this regard, the inside of the annular component 23 has a cross section that corresponds to the cross-sectional shape of the extension 2.1.1 of the roller journal 2.1, for example, a polygonal shape. On the inlet side of the central flow channel 11, the recess 10 is followed by a mounting bore 25 for the coupling sleeve 21 (see also FIG. 1). In this regard, the diameter of the mounting bore 25 is greater than the diameter of the centrally running flow channel 11. In addition, the extension 3.1.1 of the roller journal 3.1. of the roller module 3 has a mounting bore 26 that serves the same purpose.

FIG. 7 is another side view of the roller module 3 shown in FIG. 6. As in the design according to FIG. 5, in the region near the surface, the paired flow channels 15, 16 are arranged around the flow channel 11 or 12 and are sealed by covers 19. A chamber 20, which is shown only in FIG. 6, joins the paired flow channels 15, 16, so that the flow of the coolant 22 is deflected in it.

The side view also shows the polygonal design of the extension 3.1.1 as well as the mounting bore 26 for the coupling sleeve 21 and the centrally running flow channel 12, 11.

LIST OF REFERENCE NUMBERS

• 1 strand guide roller
• 2 roller module
• 2.1 inner roller journal
• 2.1.1 extension
• 2.2 outer roller journal
• 3 roller module
• 3.1 roller journal
• 3.1.1 extension
• 4 roller module
• 4.1 outer roller journal
• 5 middle bearing
• 6 middle bearing
• 7 transition region
• 8 outer bearing
• 9 outer bearing
• 10 recess
• 11 flow channel
• 11.1 supply-side outlet
• 12 flow channel
• 12.1 discharge-side outlet
• 13 coolant inlet
• 14 coolant outlet
• 15 flow channel
• 15.1 discharge-side outlet
• 16 flow channel
• 16.1 supply-side outlet
• 17 connecting channel
• 18 connecting channel
• 19 cover
• 20 chamber
• 21 coupling sleeve
• 22 coolant
• 23 component
• 24 securing means
• 25 mounting bore
• 26 mounting bore
• 27 closure cover

Claims

1-13. (canceled)

14. A modular strand guide roller for a strand guide unit of a continuous casting plant, wherein the strand guide roller comprises:

at least a first and a second roller module, which are disposed side by side in an axial direction, wherein the first roller module has a centrally located roller journal at an end face that faces the second roller module;

a middle bearing, which is positioned between the first and second roller modules for mounting and supporting the roller journal of the first roller module;

a plug connection formed between the second roller module and the roller journal for plug connection of the first and second roller modules with each other; and

a central flow channel that runs axially in the roller modules for conveying a coolant, wherein

the centrally located and axially running flow channel consists of a first separate flow channel and a second separate flow channel; wherein

flow channels are formed in the region near the surface of an outer periphery of each roller module that guides and supports the metal strand; wherein

first connecting channels connect respective flow channels with the first separate flow channel, and second connecting channels connect further respective flow channels with the second separate flow channel; and wherein

the flow channels are arranged in pairs.

15. The strand guide roller in accordance with claim 14, wherein a chamber is formed at least at one end of each pair of flow channels to deflect the coolant.

16. The strand guide roller in accordance with claim 15, wherein the flow channels and the chambers are tightly sealed from outside with detachable individual or common annular covers.

17. The strand guide roller in accordance with claim 14, wherein the respective flow channels of the paired flow channels are connected by the first connecting channels with the respective first flow channel, and the further respective flow channels of the paired flow channels are connected by the second connecting channels with the respective second flow channel.

18. The strand guide roller in accordance with claim 17, wherein the first connecting channel connects a supply-side outlet of the first flow channel with a discharge-side inlet of the respective flow channel of the paired flow channels.

19. The strand guide roller in accordance with claim 17, wherein the second connecting channel connects a supply-side outlet of the further respective flow channel of the paired flow channels with a discharge-side inlet of the second flow channel.

20. The strand guide roller in accordance with claim 14, wherein the first flow channel of the first roller module is connectable to a coolant inlet, and the second flow channel of a respective roller module is connectable to a coolant outlet.

21. The strand guide roller in accordance with claim 14, and further comprising a coupling sleeve provided to connect the second flow channel of the first roller module with the first flow channel of the second roller module.

22. The strand guide roller in accordance with claim 1, wherein a direction of flow of the coolant is reversible.

23. The strand guide roller in accordance with claim 14, wherein the first and second separate flow channels are each formed as sections of a common central flow channel and are separated from each other only by a barrier.

24. The strand guide roller in accordance with claim 14, wherein the flow channels are formed axially parallel, helically, or as an annular gap in a region of the roller module that is near the surface.

25. A strand guide unit for a metal strand emerging from a mold of a continuous casting plant, wherein the strand guide unit has at least one strand guide roller that consists of a first roller module and a second roller module designed in accordance with the features of claim 14.

26. A method for operating a strand guide unit in accordance with claim 25, wherein the coolant flows in opposite directions in adjacent strand guide rollers, adjacent roller segments, or in an upper and lower frame of a segment.