Continuous-casting crystalliser with increased heat exchange and method to increase the heat exchange in a continuous-casting crystalliser

摘要

The crystalliser (11) cooperates externally with a box-shaped structure (13) creating cooling chambers (14), in which a cooling fluid circulates, and cooperates internally with the skin of the billets, blooms or slabs (24) being formed. The cooling chambers (14) containing intermediate walls (20) create circulation channels (21) in cooperation with the outer surfaces (12) of the sidewalls of the crystalliser (11), at least one upper zone (34) being included in cooperation at least with the vicinity of the meniscus and with the portion below the meniscus (33) of liquid metal, a lower zone (26) being also included and beginning in the vicinity of the zone of separation of the forming skin from the inner surfaces (12) of the crystalliser (11) and extending towards the outlet of the crystalliser (11). By acting on the cross-section and/or conformation of at least one longitudinal portion of at least one side of the cross-section of the circulation channels (21), e.g., by providing elements to disturb the flow of cooling fluid in the circulation channels (21), and by acting on the different pressures of the cooling fluid present between the inlet and outlet of that longitudinal portion of the circulation channels (21) a desired turbulence of the cooling fluid is created which is such as to increase the coefficient of heat exchange to a value greater than 40,000 W/m.sup.2 K. The side walls of the crystallizer preferably have a thickness between 4 and 15 mm.