GB2148948A

GB2148948A - Strip cooling

Info

Publication number: GB2148948A
Application number: GB08427303A
Authority: GB
Inventors: James Colin Inman; James Francis Alsop
Original assignee: Davy McKee AG
Current assignee: Davy McKee AG
Priority date: 1983-11-04
Filing date: 1984-10-29
Publication date: 1985-06-05
Also published as: GB2148948B; GB8427303D0; GB8329587D0

Abstract

A water curtain (30) for cooling metal strip is discharged from an elongate outlet (15) formed between a side wall (10) of a manifold (7) and a plate (13). The water is supplied to the manifold from a water main (9) and passes into the outlet (15) through a slot (11). Spacers (27) are located in the outlet (15) at intervals along the length of the manifold and plate (13) is held against the spacers by bolts (29) passing through the manifold. Loading the plate (13) against the spacers reduces the risk to thermal distortion of the plate (13) due to the temperature of the strip, and consequent variation in the uniformity of the curtain (30). <IMAGE>

Description

SPECIFICATION Apparatus for cooling metal strip This invention relates to apparatus for cooling metal strip which is moving along a given path in the direction of its length, and in particular to cooling apparatus for supplying a coherent curtain of cooling liquid. By the term "coherent" is meant continuous, that is, without breaks.

It is known that, in order to achieve a desirable metallurgical structure in the metal strip being cooled, the cooling should be uniform across the width of the strip. This necessitates a cooling equipment which produces a curtain of uniform thickness throughout the cooling operation. It has been found with some cooling equipment that the water outlet nozzle expands and changes its shape due to the positioning of the nozzle close to the hot metal strip. This results in a curtain of non-uniform width.

According to a first aspect of the present invention, apparatus for cooling metal strip moving in the direction of its length along a given path comprises an elongate header extending transversely to, and spaced from, the path; means for supplying cooling liquid to the header for discharge through an elongate slot in a side wall of the header; and a plate secured in spaced reiation to that side wall with spacers therebetween at intervals along the length of the header, the spacers determining the separation of the side wall and plate which together define therebetween an elongate outlet from which a coherent curtain of the liquid is discharged.

According to a second aspect of the invention, apparatus for cooling metal strip moving in the direction of its length comprises an elongate header arranged to extend transversely to the direction of movement of the strip and spaced therefrom, means for introducing cooling liquid into the header, a slot in a side wall of the header extending substantially parallel to the length of the header, a plate spaced from said side wall and together with the side wall defining an elongate outlet from which a coherent curtain of cooling liquid is discharged, a plurality of spacers located in the outlet at intervals along the length of the header to separate the side wall and the plate, and clamping means located at intervals along the length of the header and serving to urge the wall and the plate towards each other.

The side wall and the plate are urged towards each other by the clamping means but are kept apart by the spacers. In this way, the separation of the side wall and the plate remains substantially the same even when the cooling apparatus is subject to the heat given off by the hot metal strip.

In order that the invention may be more readily understood, it will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front elevation of cooling apparatus for metal strip; Figure 2 is an enlarged end elevation of the apparatus shown in Fig. 1; Figure 3 is a perspective view of part of the apparatus shown in Fig. 2; and Figure 4 is a sectional end elevation of an alternative form of the apparatus.

Figs. 1-3 show apparatus for cooling hot metal strip as it leaves a rolling mill. The metal strip 1 moves in the direction of its length along a given path defined by a roller table indicated by reference 2. A framework 3, extending over the workpiece 1, supports cooling apparatus 4 for supplying a coherent curtain of cooling water to the upper surface of the metal strip. Apparatus 5, located below the level of the metal strip 1, serves to provide a coherent water curtain to the underside of the metal strip at a position between a pair of adjacent rollers of the roller table 2.

The apparatus for providing the water curtain on the upper surface of the strip consists basically of an elongate header 7 extending for at least the full width of the metal strip.

This header has a number of water inlet pipes 8 spaced apart along its length. The pipes 8 are connected to a water main 9 which is supported on the framework 3. The header 7 is of generally rectangular form in cross section and, towards the upper edge of a side wall 10, there is a slot 11 through that wall extending for substantially the entire length of the header. A metal plate 1 3 is arranged substantially parallel with the side wall 10 and is spaced from it and, at the lower end of the side wall 10 and plate 13, there is an outlet slot 1 5 which constitutes the outlet of the cooling apparatus. It is convenient for the side wall 10 of the header to have an upwardly directed flange 1 6 and for the plate to be connected at its upper edge to this flange with a gasket between them by a plurality of bolts 18.The header is divided along its length by partitions 20, but each of the partitions has openings 21 in it so that the water level in the header is constant along the entire length.

On the side of the plate 1 3 which is away from the header, there are stiffening webs 22 and 23. In addition to the webs, there are spaced apart lugs 25 on the face of the plate 1 3. At intervals along the length of the header, spacers 27 are positioned between the side wall 10 and the plate 13; each spacer is apertured to permit a pair of bolts 29 to pass from the outside of the header, through the header, the spacer and the space 13, and through a pair of lugs 25. Nuts are then tightened on the bolts to urge the side wall 10 and the plate 1 3 towards each other and against the spacers 27 which determine the separation of the plate 1 3 from the side wall 10.The spacers terminate well above the level of the outlet slot 1 5 and are shaped at their lower ends to encourage the water flowing down through the space between the wall and the plate and between the spacers to close up at the bottom of the spacers to produce the coherent curtain.

In use, water from the main 9 passes through the pipes 8 into the header at intervals along its length. The header fills with water until the level of the slot 11 is reached, at which stage the water spills over into the space between the side wall 10 and the plate 1 3. The water then flows downwardly through this space and emerges as a coherent curtain 30 at its bottom end. When the hot metal strip passes beneath the header and the heat from it raises the temperature of the lower edges of the side wall 10 and the plate 1 3, the bolts prevent those parts from expanding away from each other to render non-uniform the width of the nozzle outlet.

Fig. 4 shows an alternative arrangement in which the header 7 is separated from a similar header 7' and the adjacent side walls 10 and 10' define the outlet 15' from the cooling apparatus. The water is supplied through the pipes 8 to header 7 and it leaves through a slot 11. The header 7' is completely closed and has water inputs and outputs 31, 32, respectively, which enable water to be circulated through the header 7' to keep the temperature of side wall 10' substantially equal to that of side wall 10. As in the previous embodiment, spacers 27' are located between the plates 10 and 10' and the headers 7 and 7' are held firmly in contact with the spacers by bolts 29' extending through the headers in sleeves 23.

Instead of using bolts 29 to hold against the spacers 27 the plates defining the outlet (10 and 13 in Figs. 1 to 3 and 10 and 10' in Fig. 4), those plates may be permanently secured together, as by welding, with the spacers located therebetween. For that purpose, countersunk holes may be bored through the plates where the spacers are to be located, to enable a welding rod to be inserted to weld the spacer to each plate.

Claims

1. Apparatus for cooling metal strip moving in the direction of its length along a given path, the apparatus comprising an elongate header extending transversely to, and spaced from, the path; means for supplying cooling liquid to the header for discharge through an elongate slot in a side wall of the header; and a plate secured in spaced relation to that side wall with spacers therebetween at intervals along the length of the header, the spacers determining the separation of the side wall and plate which together define therebetween an elongate outlet from which a coherent curtain of the liquid is discharged.

2. Apparatus for cooling metal strip moving in the direction of its length comprising an elongate header arranged to extend transversely to the direction of movement of the strip and spaced therefrom, means for introducing cooling liquid into the header, a slot in a side wall of the header extending substantially parallel to the length of the header, a plate spaced from said side wall and together with the side wall defining an elongate outlet from which a coherent curtain of cooling liquid is discharged, a plurality of spacers located in the outlet at intervals along the length of the header to separate the side wall and the plate, and clamping means located at intervals along the length of the header and serving to urge the wall and the plate towards each other.

3. Cooling apparatus according to claim 2, in which the clamping means are bolts passing through the manifold and the plate transversely to the manifold length.

4. Cooling apparatus according to claim 3, in which the bolts pass through the spacers.

5. Cooling apparatus according to any one of the preceding claims, in which the plate has stiffening webs on its side distant from the manifold.

6. Cooling apparatus according to any one of the preceding claims, in which the spacers terminate short of the discharge opening of the outlet and are shaped to encourage liquid flowing through the outlet to close up beyond the spacers and to produce a coherent curtain.

7. Apparatus for cooling metal strip moving in the direction of its length, substantially as herein described with reference to the accompanying drawings.