CS209062B1 - Cooling nozzles holder for continuous casting - Google Patents

Abstract

It is an object of the invention to provide a cooling nozzle holder equipment for continuous casting of metal bars. On the center of each chilled area perimeter the profile of the cast metal rod is directed to the axes at least two cooling nozzle openings. These the holes are formed in the cooling nozzle holder. The axes of the holes for the cooling nozzles are in the front view viewpoint is offset by the distance that is equal to the thickness of the coolant stream and optionally they are inclined towards each other.

Description

The invention relates to a cooling nozzle holder of a device for continuously casting metal bars.

In a continuous casting plant, particularly steel, the liquid steel is initially cooled in the crystallizer, thereby forming a thin solidified crust of the casting profile on the still liquid steel, allowing the profile to gradually slide out of the crystallizer. Immediately below the crystallizer, a hot cast bar is sprayed with a stream of cooling medium, e.g. water, further cooling and thereby solidifying the bar.

The casting rod must be withdrawn from the crystallizer by a certain force which, together with the internal hydrostatic pressure in the casting rod, stresses the solidified bark of the rod. If this stress exceeds the strength of the solidified crust, it ruptures and the liquid core of the rod outflows, which means considerable losses for the operation, since the casting on the respective casting stream or possibly other casting streams of the casting device must usually be stopped; to deteriorate the cast metal, to damage the casting mechanism and to other defects and losses.

In particular, bursts occur when a failure occurs in the spray of the rod with the cooling medium just below the crystallizer. Most spray defects are caused by clogging of one or more cooling nozzles arranged around the cast bar. Quite often there are bursts of bars whose cross-section is square or similar to square, where, for dimensional reasons, only one flat-flow cooling nozzle for each wall of the cast profile is used for spraying at the individual height levels below the crystallizer. Clogging of this nozzle causes the rod to overheat, followed by a burst of liquid core.

This disadvantage is overcome by the cooling nozzle holder of the continuous metal casting apparatus according to the invention, characterized in that at least two cooling nozzle apertures are formed in the holder, the axes of which are directed to the center of each section of the cooled surface. According to the invention, these axes are offset from each other by a distance equal to the thickness of the coolant flow. It is also an object of the invention that the axes of the orifices for the cooling nozzles are in a front view vftMdMr. Λ-Γ. ~ 2. .¾ í

Claims (2)

SUBJECT Cooling nozzle holder for a continuous casting of metal bars, characterized in that at least two cooling nozzle holes (2) are provided in the holder (4), the axes of which are directed to the center of each section of the cooled surface along the perimeter of the cast metal bar profile. 1) under the crystallizer (3), 2 ex The advantage of the cooling nozzle holder according to the invention is that this arrangement allows at least a doubling of the amount of cooling medium impinging on the same circumferential section of the cooled metal rod immediately below the crystallizer, thereby ensuring reliable cooling of the metal rod even in case of clogging liquid core metal rod. The accompanying drawing shows an exemplary front view of a holder according to the invention, including a part of the crystallizer and a cast metal bar. 2 is a plan view thereof. In the nozzle holder 4 there are two openings for cooling nozzles 2 with a flat outlet shape, the axes of which are directed so that the flow of cooling medium from both cooling nozzles 2 affects the same circumference width of the cast metal rod 1 under the crystallizer 3, fig. 2. These longitudinal axis of the openings are offset relative to each other by a distance equal to the thickness of the coolant flow and at the same time are inclined relative to each other by an angle corresponding to a possible increase in the thickness of the coolant flow proportional to the increasing flow distance from the cooling nozzles 2. By inclining or offsetting the axes of the orifices of the cooling nozzles 2, the coolant flows are prevented and thus the cooling of the casting rod 1 is reliably cooled. cast metal bars 1 to cool. The total amount of coolant flowing out of these cooling nozzles 2 is therefore excessive, but since it is a relatively narrow zone of the metal rod 1, Fig. 1, limited on one side by the crystallizer device 3 and on the other by guide rollers or _; other support elements shielding the cast metal rod 1 against the impact of the coolant flow, this excess amount of coolant is not a defect and does not adversely affect the quality of the cast metal bars 1. In order to achieve a spray of the cooled section of the cast metal rod 1 as uniformly as possible, the axes of the cooling nozzles 2 enclose, in plan view, an angle as small as possible which permits the design of the cooling nozzles and their mounting. The size of this angle is at most 15 °. . - x BACKGROUND OF THE INVENTION wherein the axes are offset from each other by a distance equal to the thickness of the coolant flow. 2. Cooling nozzle holder according to claim 1, characterized in that the axes of the cooling nozzle openings (2) are inclined relative to one another in a front view.