| 摘要 |
Method and apparatus for secondary cooling of a metal strand particularly of steel by the quantity-controlled spraying of a coolant in individual cooling areas by means of nozzles on areal portions of the strand surface, which as a consequence of the strand advance are intermittently cooled in the sprayed areal portions and reheated in the unsprayed portions by the continuing heat flow from the inside of the strand, whereby the coolant quantities which are fed to the nozzles of the individual cooling areas are controlled according to predetermined values. The coolant quantity per unit time Qt (l/min) fed to each nozzle proportionally to the strand advance speed is controlled according to predetermined values of the coolant quantity QS (l/m2) which is fed to each strand surface unit by a nozzle. The coolant quantity QS for the individual cooling area (the location of which cooling areas are determined by a distance x of that nozzle of each cooling areas from the continuous casting mould in % of the total secondary cooling length, which nozzle is furthest away from the continuous casting mould) is regulated to values, which in a graph of the coolant quantity QS over the secondary cooling length lie between the points of intersection, with particular graph curves, of perpendicular lines drawn at the location of said nozzle of the individual cooling areas plotted on the abscissa which is most distant from the continuous casting mould. |
