Refractory submerged entry nozzle

Abstract

The invention relates to a refractory submerged entry nozzle (also called SEN or casting nozzle) especially but not limited for use in a continuous casting process for producing steel.

Claims

1. Refractory submerged entry nozzle providing the following features: a nozzle wall (12) surrounding a flow through channel (14) which extends between an inlet opening (16) at a first nozzle end (100), being an upper end in a use position of the nozzle, and at least one outlet opening (18.1, 18.2, 18.3) at a second nozzle end (1 Ou), being a lower end in the use position, to allow a continuous flow stream of a molten metal along said flow through channel (14) from its inlet opening (16) through the outlet opening (18.1, 18.2) into an associated molten metal bath (B), at least one intake port (20, 22) being arranged between the at least one outlet opening (18.1, 18.2, 18.3) and the said inlet opening (16) within the nozzle wall (12) in a section of said wall (12) being submerged in the molten metal bath (B) when the nozzle is in its use position, wherein at least one intake port (20, 22) is arranged between two protrusions (24l, 24r) arranged at a distance to each other on opposite sides of the intake port (20, 22) in an axial direction of the nozzle and along a common inner surface of the nozzle wall (12), to allow molten metal of the molten metal bath to penetrate via said intake port (20, 22) into the flow through channel (14).

2. Nozzle according to claim 1, wherein the at least one intake port (20, 22) is provided by an opening extending from an outer surface (120) to an inner surface (12i) of the nozzle wall (12), wherein the said opening has one of the following cross sections: circle, oval, triangle, rectangle.

3. Nozzle according to claim 1 with at least two intake ports (20, 22) arranged at opposite sides of the nozzle.

4. Nozzle according to claim 1 with two lateral outlet openings (18.1, 18.2), wherein the at least one intake port (20, 22) is arranged in a wall area between the two outlet openings (18.1, 18.2).

5. Nozzle according to claim 1, comprising at least three sections (10.1, 10.2, 10.3), namely: an upper section (10.1), including the inlet opening (16) and having a substantially circular cross-section, a middle section (10.2) which is flared outwardly in one first plane and flattened in a second plane, being perpendicular to the first plane, a lower section (10.3) comprising the at least one outlet opening (18.1, 18.2, 18.3), wherein the at least one intake port (20, 22) is arranged in the lower part of the middle section (10.2) or the upper part of the lower section (10.3).

6. Nozzle according to claim 5 comprising two lateral outlet openings (18.1, 18.2) in the lower section (10.3), arranged opposite to each other.

7. Nozzle according to claim 1, wherein the distance (d) between said two protrusions (24l, 24r) becomes smaller between their upper and lower ends.

8. Nozzle according to claim 1, wherein said two protrusions (24l, 24r) are arranged in such a way as to provide a Venturi nozzle between them.

9. Nozzle according to claim 8, wherein the smallest distance (d.sub.min) between the two protrusions (24l, 24r) is adjacent to the intake port (22).

10. Nozzle according to claim 1 with an outlet opening (18.3) extending at a lowermost end of the lower end of the nozzle.

Description

(1) The invention will now be described in more details with respect to the attached drawing schematically representing possible embodiments of the invention, namely:

(2) FIG. 1: A perspective view onto a first embodiment of a refractory submerged entry nozzle (SEN) according to the invention,

(3) FIG. 2: The SEN according to FIG. 1 in a longitudinal sectional view in its functional position within a tundish.

(4) FIG. 3: The SEN according to FIG. 2 in an enlarged scale.

(5) FIG. 4: An enlarged view onto one intake port of the SEN according to FIGS. 2, 3.

(6) FIG. 5: A view according to FIG. 3 for a second embodiment.

(7) FIG. 6: A view according to FIG. 4 for the second embodiment.

(8) FIG. 7: A view according to FIG. 3 for a third embodiment.

(9) FIG. 8: A view according to FIG. 4 for the third embodiment.

(10) FIG. 9: A view according to FIG. 3 for a fourth embodiment.

(11) FIG. 10: A view according to FIG. 4 for the fourth embodiment.

(12) In the Figures functionally identical or similar construction details are characterized by the same numerals.

(13) FIG. 1 is a perspective view onto a submerged refractory entry nozzle (SEN) according to the invention. It has a generally tube-like shape, comprising a nozzle wall 12, surrounding a flow through channel 14 (FIG. 2) which extends between an inlet opening 16 at a first nozzle end 10o, being an upper end in the use position of the nozzle (FIG. 2) and two lateral outlet openings 18.1, 18.2 at a second nozzle end 10u, being a lower end in the use position. This design allows a continuous flow stream of a molten metal from the inlet opening 16 along the flow through channel 14 downwardly and through the outlet openings 18.1, 18.2 into an associated molten metal bath B (FIG. 2).

(14) The SEN further comprises two intake ports 20, 22 being arranged between the outlet openings 18.1, 18.2 and the inlet opening 16 within the nozzle wall 12 within a section of said nozzle wall 12, which is submerged in the molten metal bath B when the nozzle 10 is in its use position (FIG. 2) to allow molten metal of the molten metal bath (B) to penetrate via said take intake ports 20, 22 into the flow through channel 14 and further leaving the flow through channel 14 via outlet ports 18.1, 18.2 and/or a third outlet opening 18.3 at the lowermost end of nozzle 10.

(15) FIG. 2 further represents a mould flux F on top of the melt bath B, defining a casting level L-L.

(16) As may best be derived from FIGS. 2-4 intake ports 20, 22 are arranged along a height of the adjacent lateral outlet openings 18.1, 18.2 (seen in an axial direction A-A of nozzle 10, i. e. in flow direction of the melt through the nozzle).

(17) Each intake port 20, 22 is provided by an opening extending from an outer surface 12o to an inner surface 12i of the nozzle wall 12 wherein said opening has a circular cross section.

(18) In other words: The intake ports 20, 22 are arranged in a wall area between the two outlet openings 18.1, 18.2 and within a more or less planar wall section between the said two outlet openings 18.1, 18.2 (FIG. 1).

(19) In the embodiment described in FIGS. 1-4 the overall nozzle is characterized by an upper section 10.1, including the outlet opening 16, which upper section has a substantially circular cross section. It is further characterized by a middle section 10.2, which is flared outwardly in one first plane and flattened in a second plane, being perpendicular to the first plane. It further comprises a lower section 10.3, comprising the outlet openings 18.1, 18.2, 18.3 and the intake ports 20, 22. The intake ports 20, 22 are arranged in the lower fourth (fifth) of the axial length of the nozzle.

(20) Each of said intake ports 20, 22 is arranged between two protrusions 24l, 24r, arranged at a distance to each other on opposite sides of the respective intake port (22 in FIG. 3) and in the axial direction of the nozzle as well as along the same inner surface 12i of the nozzle wall 12.

(21) These protrusions 24l, 24r provide a gap in between, in which gap the said intake port 20, 22 is arranged. The intake port 20, 22 merges into this gap. Consequently, the central melt stream, flowing substantially vertically downwards (FIG. 3 arrow F) is guided along this gap (on the inner side of surface 12i) accelerated and providing a back pressure, namely a low pressure (partial vacuum) in the space around said intake port. This causes the molten melt within the melt bath B to enter the intake port 20, 22 and to flow through said intake port 20, 22 into the main melt stream (within flow through channel 14). At the same time the metal melt bath on the respective side of nozzle 10 is set into motion, while further metal melt is flowing through said intake port into the nozzle.

(22) The protrusions 24l, 24r according to the embodiment of FIGS. 1 to 4 have a triangular profile (in a view according to FIG. 4, thus providing a kind of a Venturi nozzle, which further increases the melt velocity, passing the gap between said two protrusions 24l, 24r in a downward direction (arrow F in FIGS. 3, 4).

(23) The Venturi design is characterized in that width d of the gap between opposed protrusions 24l, 24r gets smaller in the upper part and larger in the lower part, with d.sub.min in-between wherein intake port 22 is arranged between the lower parts of said protrusions 24l, 24r.

(24) The embodiments of FIGS. 5 to 10 differ from the embodiment of FIGS. 1 to 4 only with respect to the design of the said protrusion(s).

(25) The example of FIGS. 5, 6 discloses a funnel shaped monolithic protrusion 24, i. e. the lower part of said protrusion 24 covers the corresponding intake port 22 partially and with a distance to the inner end of said intake port 22.

(26) The embodiment according to FIGS. 7, 8 is characterized by a box-like protrusion 24, which allows the intake port 22 to become longer such that the corresponding melt stream flowing into nozzle 10, enters the flow through channel 14 at a distance to said inner nozzle wall 12i.

(27) The embodiment according to FIGS. 9, 10 is similar to that of FIGS. 7, 8 with the proviso that said box-like protrusion has an opening 24o at its lower end and a slit 24s at its upper end to allow the main stream of the metal melt to pass said intake port 22 after passing slit 24s and before passing opening 24o.