GB2027166A

GB2027166A - Cooled rollers

Info

Publication number: GB2027166A
Application number: GB7925717A
Authority: GB
Original assignee: Voestalpine AG
Current assignee: Voestalpine AG
Priority date: 1978-08-03
Filing date: 1979-07-24
Publication date: 1980-02-13
Also published as: DE2929342A1; BR7904950A; AT357714B; BE877984A; DE7828018U1; SE7906127L; IT7924844A0; ES483122A1; FR2432355A1; ATA563078A; JPS5522493A

Abstract

A hollow strand guiding roller for a continuous casting plant comprises stationary cooling-agent supply and discharge conduits 17, 16 so mounted at the roller end(s) 4, 5 as to permit rotational movement of the roller body 1 relative to the conduits, the cooling-agent supply conduit 17 including outlet openings 23 whose axes 22, and thus the axes 24 of the cooling-agent jets 25, enclose an acute angle (32) with the conduit axis (31). <IMAGE>

Description

SPECIFICATION Improvements in or relating to a strand guiding roller arrangement The invention relates to a strand guiding roller, in particular for a continuous casting plant for slabs, comprising a hollow roller body into whose cavity a cooling-agent supply conduit extending in the axial direction of the roller body projects from at least one roller end, and in which at least at one end of the roller body a cooling-agent discharge conduit is provided, entering into the cavity, wherein the cooling-agent supply and discharge conduits are mounted at the roller end(s) on aliowing for a rotational movement of the roller body relative to the cooling-agent supply and discharge conduits standing still, and wherein, in addition, the cooling-agent supply conduit(s) include outlet openings, preferably nozzle-shaped outlet openings, distributed over their length(s).

With rollers of this kind, which are known from German patent No.451,977, the cooling agent is supplied via a rigid pipe guided through the hollow neck of the roller, extending in axial direction within the roller, and provided with outlet openings for the cooling agent. With such an inner cooling of the roller, cooling of the roller jacket on avoiding an isolating air gap is possible, yet there will emerge difficulties with very long rollers, as are used particularly with continuous casting plants for slabs. Discharge of the cooling agent is effected, with the known cooled roller, at a bearing neck af the roller, thus causing turbulent currents in the cooling agent gathering in the interior of the roller, in particular if the roller is of a great length, so that a well-defined flowing off of the cooling agent will not be guaranteed.It may happen that part of the cooling agent remains within the roller for a longer period of time than does another part, a differing cooling effect of the cooling agent thus being likely to occur.

The invention aims at avoiding the difficulties pointed out and has as its object to provide a strand guiding roller in which an even cooling of the roller is ensured and in which the discharge of the cooling agent takes place in a weil-defined flow in the interior of the roller also with long rollers.

These objects are achieved according to the invention in that the axes of the outlet openings and thus the axes of the cooling agent jets enclose an acute angle with the axis of the roller body.

Thereby, it is reached that the cooling-agent jet encloses an acute angle with the jacket face, the cooling agent thus being moved in the axial direction of the roller through the roller.

An advantageous embodiment is characterized in that the axes of the outlet openings and thus the axes of the cooling-agent jets enclose an acute angle with the tangent plane laid at the roller jacket in the intersection of these axes with the roller jacket, wherein it is advantageous, if the axes of the outlet openings and thus the axes of the cooling-agent jets are arranged eccentrically of the roller body. By this arrangement of the outlet openings, the cooling agent flows off in a screw-like manner, at least over part of the jacket.

With rollers arranged on the upper side of a horizontal strand guide, a better turbulence af the water being in the lower half of the cavity of the roller and a better supply in the direction towards the roller ends are thus created.

The invention will now be explained in more detail with reference to the accompanying drawings, wherein: Fig. 1 is a longitudinal section according to one embodiment through the axis of a strand guiding roller; Fig. 2 illustrates a further embodiment in an illustration analogous to Fig. 1; and Fig. 3 is a section transversely to the roller axis according to line Ill-Ill of Fig. 2.

By 1 a roller body is denoted which is formed of pipe sections 2 and hollow bearing necks 3 arranged between the pipe sections, as well as bearing necks 6 situated at the ends 4 and 5 of the roller body. These parts are welded together into a construction unit. The bearing necks 3 are supported relative to a stationary supporting frame 8 in divided antifriction bearings 7 schematically illustrated. The cavity formed by the roller body 1 is narrowed at each bearing neck 3 and 6, respectively, and widened in the region of the pipe parts 2, so that the roller body 1 has the same wall thickness over substantially all of its longitudinal extension.At the end 4 of the roller body 1, a lid 9 is fixed by screws 10, which lid also serves for fastening the breaing 11 which is slipped on the bearing neck 6 and also stationarily supported. This lid 9 has a central opening penetrated by a cooling-agent discharge pipe 12.

The pipe 12 is designed in one piece, with an outer lid 13 which delimits a casing 1 4 outwardly surrounding the bearing 11. On this outer lid 13, a cap 1 5 is centrally put on, in which a discharge pipe 16 is laterally inserted. The cap is centrally penetrated by a cooling-agent supply pipe 1 7 welded into the cap 1 5 and extending through the entire cavity 18 of the roller body as far as to the opposite roller end 5, on leaving free annular channels 19 at the bearing necks 3 and 6.At the roller end 5, an equal arrangement of lids 9, 13 and 1 5 is made, as at the end 4 - here, the lids are denoted accordingly by the reference numerals 9', 13' and 1 5'-, yet the pipe 17 penetrates the cap 1 5', so that the pipe 17, together with the cap 1 5, can easily be removed from the roller. It is also possible to design the pipe 1 7 in two parts, one part each extending from one end 4 and 5, respectively, of the roller body to about the middle (to half the roller length) of the cavity 18.Along the pipe 17, outlet openings are provided, which in the drawing are shown as schematically illustrated nozzles 20 whose openings are each directed towards the roller body part that is in immediate contact with the slab strand 21.

The cooling agent is streaming through a connecting conduit not illustrated, into the pipe 17, and through the pipe 17, to the nozzles 20 through which it is sprayed against the jacket of the roller body 1, gathers in the lower half of the roller body 1 and is flowing off through the pipes 12, the caps 15, 15', and the discharge pipes 16, out of the cavity 18 8 of the roller body. The axes 22 of the outlet openings 23 of the nozzles, and thus the axes 24 of the cooling-agent jets 25, enclose an acute angle 32 with the axis 31 of the roller body, whereby a good conveyance of the cooling agent in the direction to the roller ends 4 and 5 is effected.

According to the embodiment illustrated in Figs. 2 and 3, the axes 22' of the nozzles 23' of the pipe 17', and thus the axes 24 of each cooling-agent jet 25, enclose an acute angle 29 with the tangent plane 28 laid onto the roller jacket through the intersection 26 of these axes and the roller jacket 27, the nozzles 23' being arranged eccentrically of the roller body 1; i.e. the axis 22' of each nozzle 23' lies at a normal distance 30 relative to the roller axis. This is reached by a cranked pipe 17', the pipe 1 7' being crank-designed at the mounting sites centrally through the rollers, and between the mounting sites by the distance 30 to the axis 31 of the roller.

In addition, the axes 22' of the nozzles 23' enclose an acute angle 32 with the axis 31 of the roller body 1.

By the first measure it is reached that the cooling-agent jet 25, after impinging on the roller jacket, propagates at the same in the circumferential direction of the roller. By the second measure, a propagation of the coolingagent jet also in the axial direction of the roller is effected. The combination of both measures ensures a screw-like streaming of the coolingagent jet along at least part of the jacket of the roller body.

The invention is not limited to the embodiment illustrated in the drawing, but can be modified in various ways. For instance, it is possible to arrange the pipe 1 7 eccentrically, farther removed from the wall of the roller body to be cooled, whereby it is possible, on account of the greater distance of the pipe 17 from the roller jacket, to reach the same cooling effect with fewer nozzles. The roller according to the invention can be applied also in casting plants for billets or blooms, wherein the roller body, according to the smaller dimension of the billet or bloom, suitably is mounted only at the ends. The outlet openings can also be varied in various aspects; for instance, it is possible to provide bores at the pipe 17 or to insert short pipe sections into the pipe 1 7 through which the cooling agent is sprayed against the jacket of the roller body. The roller body 1 can be formed also of parts 2, 3 and 6 merely slipped one into the other and pressed against one another by clamping anchors.

Claims

1. A strand guiding roller arrangement, in particular for use in a continuous casting plantfork slabs, of the type including a hollow roller body surrounded by a roller jacket and defining a cavity, a cooling-agent supply conduit extending in the axial direction of said roller body and projecting into said cavity from at least one end of the roller body, a cooling-agent discharge conduit provided on at least one end of the roller body and entering into said cavity, and means for mounting said coolingagent supply conduit and said cooling-agent discharge conduit at the respective end of the roller body so as to allow for a rotational movement of said roller body relative to said cooling-agent supply conduit and said coolingagent discharge conduit standing still, said cooling-agent supply conduit including outlet openings for cooling agent jets distributed over its length, the improvement which is characterized in that the outlet openings and thus the cooling agent jets have axes enclosing an acute angle with the axis of said roller body.

2. A strand guiding roller as set forth in claim 1, wherein said outlet openings are nozzle-shaped.

3. A strand guiding roller as set forth in claim 1, wherein the axes of said outlet openings and thus the axes of Isaid cooling-agent jets enclose an acute angle with the respective tangent plane laid onto the roller jacket in the point of intersection of said axes with said roller jacket.

4. A strand guiding roller as set forth in claim 1, wherein the axes of said outlet openings and thus the axes of said cooling-agent jets are arranged eccentrically of said roller body.

5. A strand guiding roller substantially as hereinbefore described with reference to the accompanying drawings.