Submerged entry nozzle

Abstract

An exemplary embodiment relates to a submerged entry nozzle (SEN) for use in metallurgy, in particular for transporting a metal melt from a first metallurgical unit to a second metallurgical unit, for example during slab production in continuous casting of ferrous and non-ferrous melts. The SEN is called nozzle hereinafter.

Claims

1. Submerged entry nozzle comprising a substantially tubular body with a central longitudinal axis (LA) and a passageway (16) extending from an inlet port (12) at a first end of the nozzle, which is the upper end of the nozzle in its use position, toward a second end of the nozzle, which is the lower end of the nozzle in its use position, wherein the second end of the nozzle provides a bottom (22b) which is either flat or convex, when seen from the outside, wherein said passageway (16) merges into at least one outlet port (18), which is designed as a long slit, wherein the slit has long side walls (18w) extending in a plane arranged at an angle of <45 degrees to a plane comprising the central longitudinal axis (LA), wherein the slit has a spiral or helix-like extension and continuously extends from a position at a distance to the bottom (22b) into the said bottom (22b), to allow a metal melt to flow out of the nozzle in a horizontal and in a vertical direction.

2. Submerged entry nozzle according to claim 1, wherein the slit has a linear extension.

3. Submerged entry nozzle according to claim 1, wherein 5-30% of the length of the slit extend within the bottom (22b) of the nozzle.

4. Submerged entry nozzle according to claim 1, wherein the slit has a length, which is more than 3 times its width.

5. Submerged entry nozzle according to claim 1, with several slits, arranged at equal angles to each other along the outer periphery of the nozzle.

Description

(1) The invention will now be described with respect to the attached drawing which Shows—in schematic representations—in

(2) FIG. 1: a side view of a first embodiment of the new nozzle

(3) FIG. 2: an enlarged view of the nose portion of the nozzle of FIG. 1

(4) FIG. 3: a 3-dimensional view from below onto the nose portion according to FIG. 2

(5) FIG. 4: a side view of a second embodiment of the new nozzle

(6) FIG. 5: an enlarged view of the nose portion of the nozzle of FIG. 4

(7) FIG. 6: a 3-dimensional view from below onto the nose portion according to FIG. 5

(8) FIG. 7: a 3-dimensional view onto the lower central section and the bottom of a third embodiment of the new nozzle

(9) In the Figures same numerals are used to identify identical parts or parts of similar function (in technical terms)

(10) FIG. 1 shows a submerged entry nozzle, shaped as a rod with a tubular body, comprising an upper section 10 with an inlet port 12, a central portion 14, comprising a passageway 16, which extends from said entry port 12 to an outlet port 18. The passageway 16 is delimited by an inner surface 20 of the refractory ceramic nozzle wall 22 (tubular body). A lower bottom portion 22b, shaped like a dome (convex when seen from the outside) and extending from that part of the nozzle where the outer nozzle diameter diminishes (characterized by line A) to the lowermost end of the nozzle (characterized by line B).

(11) The outlet port 18 is split into four slit-like outlet openings 18.1 . . . 18.4 (FIG. 3) arranged at equal distance to each other around the outer nozzle wall 22.

(12) Each slit 18.1 . . . 18.4: extends from an upper end (characterized by line C), arranged in the lower zone of the central section 14 into the bottom 22b and further downwardly to an area characterized by line D, has a length, with is about 10 times its width, has a helical/spiral/helix shape between upper and lower end, has side walls 18w which are parallel to a plane comprising a central longitudinal axis LA of the nozzle.

(13) Thus the metal enters the nozzle via 12, flows through passageway 16 towards the lower end of said nozzle and leaves the nozzle by its four slit-like outlet openings 18.1 . . . 18.4.

(14) Because of the shape and arrangement of these slits 18.1 . . . 18.4 the metal stream, leaving the nozzle, has a vertical (downward) flow component (mainly caused by the lower part of the slits in the bottom section 22b) as well as an angular momentum (mainly caused by the helix shape of the slits 18.1 . . . 18.4 and the lower part of the slits in the bottom section 22b), which reduces turbulences and collisions with an adjacent wall of a corresponding mold.

(15) The embodiment of FIGS. 4-6 differs from that of FIG. 1-3 as the bottom 22b is flat, in this embodiment perpendicular to axis LA, wherein upper and lower end of bottom section 22b are defined by the upper and lower flat surfaces of the bottom and symbolized again by lines A, B in accordance with FIG. 1-3.

(16) The lower part of outlet slits 18.1 . . . 18.4 extends along said horizontal bottom 22b (FIG. 6) i.e. it penetrates said bottom 22b, thus giving the melt a strong vertical and twist component when leaving these bottom openings.

(17) FIG. 7 disclosed an embodiment similar to that of FIG. 4-6 with the following differences: it comprises only one slit 18.1 said slit 18.1 has a linear extension said slit 18.1 and its side walls are tilted with respect to the vertical

(18) The embodiment according to FIG. 7 may be amended inter alia by implementing 2 or more slits in accordance with FIG. 1-6 or in a different way.