The invention relates to a continuous casting method according to the preamble to Claim 1 and to an apparatus for implementing the method according to the preamble to Claim 9.
With curved continuous casting of preliminary profiles, in particular double T preliminary profiles or beam blank preliminary profile strands which have a bar and two side flanges, the cooling water is collected between the flanges on the inside of the radius in the preliminary profile strand and can only run off downwards along the preliminary profile strand. The cooling water must be removed from the internal curve before the gas cutting of the preliminary profile strand so that cutting is actually possible. In addition, the downwardly running cooling water results in excessive cooling in the profile flanges. Due to this cracks can occur in the strand when aligning the latter. Due to the stronger cooling of the inside of the profile the material contracts more strongly here than on the outside of the profile, due to which the radius wants to be reduced. The effect of this change to the radius is additional loading of the guide rollers on the inside.
As disclosed, for example, in EP 1 497 056 B 1, it is known to draw off the cooling water in the region of the curved strand guide of the preliminary profile strand from the internal curve of the profile or to blow it off by means of compressed air. With all of these methods it is difficult to come sufficiently close to the preliminary profile strand in order to produce a sufficiently good water seal. The use of compressed air blown into the gap in order to improve the seal brings about additional strong cooling, which is undesirable. Moreover, the amount of compressed air required is costly for the operator.
The object forming the basis of the present invention is to propose a commercially advantageous method of the type specified at the start and to provide an apparatus for implementing the method, with which the excessive cooling in the internal curve of the preliminary profile strand can largely be avoided.
This object is achieved according to the invention by a method having the features of Claim 1 and by an apparatus according to Claim 9.
Preferred further embodiments of the method according to the invention and of the apparatus according to the invention form the subject matter of the dependent claims.
With the method according to the invention and the apparatus according to the invention the excessive cooling caused by downwardly running cooling water can be largely avoided in the inner curve of the preliminary profile strand, only water nozzles being used. Neither additional baffle plates or funnels in the shoulder region, i.e. between the side flanges and the bar of the preliminary profile, nor compressed air is required. The associated installations and operating costs are therefore also dispensed with.
The additional cooling effect provided by the diverting water can be compensated by the reduction of the cooling water. In order to reduce the undercooling, heated diverting water can be used.
With the method according to the invention the cooling of the preliminary profile strand can be effected by adjusting the diverting water temperature.
In the following the invention is described in greater detail by means of the drawings. These show as follows:
The preliminary profile strand 3 passing vertically out of the mould 2 is guided through a curved strand guide 10 and bent into the horizontal. Aligned by an aligning unit 11 it passes to a gas cutting machine 12. The strand guide 10 comprises a number of strand guide segments and modules 10a, 10b disposed one behind the other (two are indicated in
Whereas the cooling water can flow away downwards without any problem away from the preliminary profile strand 3 from the outside (from the bar side 4a and from flange parts 5a, 6a according to
The two water nozzles 21, 22 are preferably connected to a common water attachment 23. For better squirting of the internal curve of the profile they can advantageously be disposed such as to be moveable to and fro laterally to the side flanges 5, 6.
The water nozzles with the diverting water are advantageously already used in the initial, substantially still vertical region of the curved strand guide 10 and disposed, for example, in the region between the two first strand guide segments 10a, 10b (indicated by arrow A in
However, it is also possible to dispose the water nozzles 21, 22 in approximately the central region of the curved strand guide 10, e.g. after the second strand guide segment 10b according to
Needless to say, the water nozzles 21, 22 or a plane common to the two water nozzles 21, 22 could also enclose an angle of between 0° and 90°.
With the method according to the invention and the apparatus according to the invention the excessive cooling caused by downwardly running cooling water can largely be avoided in the internal curve of the preliminary profile strand, only water nozzles being used. Neither additional baffle plates or funnels in the shoulder region, i.e. between the side flanges of the preliminary profile, nor compressed air is required. Therefore, the associated installations and operating costs are also dispensed with. The water used in any event in this region is available free of charge. The diverting apparatus is located outside of the shoulder region, and so there can be no collision between the casting strand and the diverting apparatus.
The additional cooling effect due to the diverting water can be compensated by reducing the downwardly flowing cooling water. In order to reduce the undercooling, heated diverting water can be used.
With the method according to the invention the cooling of the preliminary profile strand can be advantageously effected by adjusting the diverting water temperature.
Number | Date | Country | Kind |
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09 003 346.5 | Mar 2009 | EP | regional |