Title of Invention

SUBMERGED ENTRY NOZZLE FOR CONTINUOUS CASTING

Abstract A submerged entry nozzle is disclosed. Said submerged entry nozzle comprises an inlet member of a refractory material with a trumpet shaped inlet, and other portions including an upper part (31) continuous from the inlet, having a flow passage section of an elongated hole form with a great long side distance (e) and a small short side distance (f) in overall, with a fixed sectional area, a transit part (32) continuous from the upper part (31), having a nozzle wall thickness which becomes the thinner gradually as it goes toward an outlet of the nozzle the farmer, and a flow passage section of an elongated hole form with a short side distance (e) which becomes the greater as it goes toward the outlet of the nozzle the farther, and a long side distance (f) which becomes the smaller as it goes toward the outlet of the nozzle the farther, while an area of the flow passage section is kept constant, and a lower part (33) continuous from the transit part (32), having a nozzle wall thickness which has almost no change as it goes toward the outlet, a short side distance which increases moderately compared to the short side distance increase in the transit part, and symmetric outlets with reference to a splitter (34) at an end portion of the lower part (33) for guiding a molten metal flow into a mold.
Full Text SUBMERGED ENTRY NOZZLE FOR
CONTINUOUS CASTING
Technical Field
The present invention relates to submerged entry nozzles for continuous casting, and
more particularly, to a submerged entry nozzle in which molten metal is made to be supplied
to a mold without sudden change of a flow speed to induce uniform distribution of the molten
metal discharged from the submerged entry nozzle, for securing even thickness of solidified
cells, to produce good quality cast pieces.
Background Art
In general, the continuous casting, continuously casting molten metal into a mold
with an opened bottom to draw cast continuously as the molten metal solidifies, is used for
production of elongated products with a simple section, such as square, rectangle, circle, and
the like, and slab, bloom, and billet.
The continuous casting is carried out by continuous caster provided with a tundish,
molds, a secondary cooling rack, a pinch roller, and a cutter.
Particularly, the tundish receives the molten metal from the ladle and supplies to the
mold, during which control of a supply rate of the molten metal, distribution and storage of
the molten metal supplied to the molds, and separation of slag and non-metallic inclusions
(impurities in the molten metal), are made.
In this instance, flow of the molten metal in the mold gives a great influence to a
quality of the cast, and it is required that the molten metal is not exposed to air for preventing

the molten metal from oxidizing and nitration.
By providing a nozzle at an outlet of the tundish, and putting an end of the nozzle in
the molten metal in the mold, the flow of the molten metal through the mold can be
controlled, and the exposure of the molten metal to air can be prevented.
That is, the submerged entry nozzle used in casting of molten metal is provided
between the tundish and the mold, and prevents the molten metal from oxidizing and nitration,
and controls a molten metal flow through the mold, thereby enhancing quality of cast.
Particularly, the submerged entry nozzle for continuous casting of thin slab with a
thickness in a range of 50 - 80 mm has a long axis outside diameter in a range of 40 - 60mm,
and a length greater than 1000mm.
A flow pattern of the molten metal in the mold of the continuous caster for
production of the thin slab is influenced from prevention of entrainment of a molding agent,
and securing uniform cooling capability of the cast by means of stabilization of a surface of
the molten metal, and prevention of break out by means of the entrainment of the molding
agent.
Therefore, for stable operation of the continuous casting of the thin slab, securing a
strict flow pattern is essential, for which a variety of shapes of submerged entry nozzles have
been developed and used.
For reference, FIG. 1 illustrates a flow pattern of molten metal discharged into a mold
from a related art submerged entry nozzle, schematically.

In casting a thin slab, flow of the molten metal S1, S2, and S3 discharged into the
mold 3 through the submerged entry nozzle form a downward flow in the vicinity of a sphtter
2.
Moreover, a minimum sectional area, and an outlet speed vary with a form of the
splitter 2, and according to which the flow of the molten metal into the mold 3 changes.
That is, the minimum sectional area of the outlet varies the outlet speed at the outlet
of the submerged nozzle, and the molten metal flow at the sphtter 2 varies with the oudet
speed.
In general, the flow of the molten metal S1, S2, and S3 discharged into the mold 3
through the submerged entry nozzle 1 has paths as shown in FIG. 1.
A molten metal flow S1 discharged along an inside wall of the submerged entry
nozzle 1 forms a reversed flow as entrance into the mold of the flow S1 is blocked by a
molten metal flow S2 discharged from a central portion of the outlet, such that the flow S1
hits a wall of the mold 3, and therefrom rises. A speed of the reversed flow changes a height
of a surface S0 of the molten metal, that causes instabdity of the surface S0 of the mold 3.
Instability of the molten metal, particularly, the instability of the molten metal
surface S0 causes non-uniform lateral direction heat transfer inside of the mold 3, to cause
difficulty in formation of solidifying cells.
The molten metal flow S2 dirough a central portion of the outlet has a fastest flow
speed among the flow speeds of the flows S1, S2, and S3, and hits the inside wall of the mold

3 to form a downward flow.
The molten metal flow S2 influences the molten metal flow S1 discharged along an
inside wall of the submerged entry nozzle 1 to form a reversed flow, which is described
before.
Though the molten metal flow S3 along a sloped surface of the splitter 2 forms a
downward flow, the molten metal flow S3 forms an upward flow as the molten metal flow S3
collides with the molten metal flow S2 discharged through the central portion of the outlet,
and a stagnant region at a lower portion, to reverse a flow direction. The upward flow
influences formation of a solidifying layer in the mold 3.
A related art submerged entry nozzle will be described with reference to the attached
drawings.
FIGS. 2A - 3 illustrate submerged entry nozzles disclosed in Japanese Laid Open
Patent No. 2000-233262 (hereafter called as "related art 1").
As shown, the submerged entry nozzle in the related art 1 has a cylindrical upper part
21 of the body 10, a primary transit part 22 expanded toward the outlets 26, and 27, and a
main transit part 24 having the same diameter of the first transit part 22, wherein an end of
the primary transit part 22 has an angle 'a' of 0 - 60°, the slope has an angle 'b' of 30 ~ 80°,
and T/t is within a range of 75 - 200%.
Since the splitter 25 of the related art 1 submerged entry nozzle has a flat upper
surface 61, the molten metal flows along the inside wall of the body 10 of the submerged

entry nozzle, hits the upper surface 61 of the splitter 25, and sprayed outwardly, and causes a
non-uniform flow in the mold because the molten metal flow from the submerged entry
nozzle into the mold can not be induced to be symmetry due to great change of flow speed
and pressure in a course of discharge of the molten metal.
Moreover, even if the slope of the splitter 25 has an angle 'b' of 30 ~ 80°, rapid
increase of a flow speed of the molten metal at an outside circumference 62 wear down the
splitter 25, to change the slope angle of the splitter 25, resulting in change of flow pattern of
the molten metal in the mold as a casting time period increases.
Along with this, in a case T/t is below 100%, because a location of molten metal
hitting point 'F' on a wall of the mold becomes closer to the surface S0, the molten metal
flow S1 discharged along the inside wall of the nozzle to form the reversed flow is involved
in speed increase, together with an increase of the flow S1 area, to cause a height difference
of the surface to be more than 10mm, that causes difficulty in operation.
FIGS. 4A and 4B illustrate a submerged entry nozzle in PCT/CA95/00228 (hereafter
called as "related art 2").
As shown, the related art 2 submerged entry nozzle is configured similar to a nozzle
which has a cylindrical upper part 21 of a body 10, a primary transit part 22 having a short
side distance of a flow passage increased as it goes toward outlets 26, and 27, and a long side
distance of the flow passage decreased as it goes toward outlets 26, and 27, and a main transit
part 24 having a long side distance the same with an end of the primary transit part 22,

wherein a total converging angle 'c' of front/rear walls 22A, and 22B is 2.0 - 8.9°, preferably
5.3°, a total diverging angle 'd' of the side walls 22c, and 22d is 6 ~ 16.6°, preferably 10.4°,
and an angle of a deflection part 26, and 27, outlets, is 10 ~ 80°, preferably 30°.
However, the related art 2 submerged entry nozzle has a problem of occurrence of a
non-uniform flow caused by difference of central flow speed 51a and inside wall flow speed
52A in a lateral direction of the submerged entry nozzle due to an increased short side
distance of the submerged entry nozzle if a total divergence angle 'd' of the side wall is more
than 5° even if a change rate of a sectional area of the flow passage is small.
Moreover, since the central flow speed higher than the inside wall of the nozzle
concentrates the molten metal flow on the splitter 25, to form a double roll flow pattern,
bringing the hitting point 'F' in FIG 1 close to the surface S0, to make the reversed flow S1,
and the area thereof larger, a height difference of surface S0 variation becomes greater,
causing difficulty in stable operation.
Thus, the related art submerged entry nozzles shows a great change of flow speed
and pressure of the molten metal in the nozzle due to great change of sectional area from the
inlet to the outlet, causing rapid pressure change in the nozzle as the molten metal passes
through a barrier of a high pressure.
The pressure change occurred thus forms a pressure wave, which is transmitted to
upper and lower portions of the nozzle.
Particularly, even if the pressure wave transmitted to the upper portion is attenuated

at the nozzle inlet, since the pressure wave transmitted to the lower portion causes pulsation,
to make a flow speed and a discharge rate non-uniform, it is difficult to maintain the surface
SO of the molten metal in the mold constant, and moreover, a non-uniform flow is caused by
the difference of flow speed.
Consequently, solidification of the molten metal is delayed locally, to form a
solidifying cell having a thickness thinner man other portions, that forms a tensile stress, and
a longitudinal crack in a slab surface.
Eventually, a submerged entry nozzle is required, which can solve the foregoing
problems by preventing rapid change of the flow speed and pressure in the submerged entry
nozzle.
Disclosure of Invention
An object of the present invention for solving the foregoing problems is to provide a
submerged entry nozzle having optimized nozzle inside form and splitter form, in which
changing ranges of flow speed, and pressure inside of a nozzle are minimized in continuous
casting for suppressing formation of a stagnant area of the molten metal, reduces a difference
of heights of the molten metal surface by forming symmetric flow of the molten metal in the
mold, and stabilizes flow of the molten metal to enable production of good quality cast by
forming a uniform thickness of solidifying cells.
The object of the present invention can be achieved by providing a submerged entry
nozzle for continuous casting including an inlet member of a refractory material with a

trumpet shaped inlet, and other portions including an upper part continuous from the inlet,
having a flow passage section of an elongated hole form with a great long side distance and a
small short side distance in overall, with a fixed sectional area, a transit part continuous from
the upper part, having a nozzle wall thickness which becomes the thinner gradually as it goes
toward an outlet of the nozzle the farther, and a flow passage section of an elongated hole
form with a short side distance which becomes the greater as it goes toward the oudet of the
nozzle the farther, and a long side distance which becomes the smaller as it goes toward the
oudet of the nozzle the farther, while an area of the flow passage section is kept constant, and
a lower part continuous from the transit part, having a nozzle wall thickness which has almost
no change as it goes toward the outlet, a short side distance which increases moderately
compared to the short side distance increase in the transit part, and symmetric oudets with
reference to a splitter at an end portion of the lower part for guiding a molten metal flow into
a mold, wherein an area of the flow passage section increases gradually within a range of 5%
with reference to an area of a flow passage section at a location where the flow passage starts
at an end of the inlet in the upper part as it goes toward the outlets the farther until the splitter
starts, where the flow passage sectional area restores to the area the same with the reference
area until the outlets terminate.
The flow passage section of the upper part includes a straight long side and a
curved short side with a fixed curvature, and a ratio of the short side distance to the long side
distance is 1.1 — 4.0.

The flow passage section of the transit part includes a straight long side and a curved
short side with a fixed curvature, wherein the short side distance increases, and the long side
distance decreases, compared to the flow passage section of the upper part, wherein a long
side inside wall is sloped by an angle of 1.0 - 8.0° to a vertical line, and a short side inside
wall is sloped by an angle of 5.0 - 20.0° to a vertical line.
The lower part includes a short side inside wall sloped by 2 - 20° to a vertical line,
which is smaller than the angle of the slope of the short side inside wall of the transit part.
The splitter includes a short side inside wall sloped by a predetermined angle to a
vertical line substantially starting from a middle of a length thereof in a direction of the outlet,
and a lower portion sloped by an angle in a range of 2 ~ 20° to the vertical line.
Brief Description of the Accompanying Drawings
The accompanying drawings, which are included to provide a further understanding
of the invention, illustrate embodiment(s) of the invention and together with the description
serve to explain the principle of the invention. In the drawings;
FIG. 1 illustrates a flow pattern of molten metal discharged into a mold from a related
art submerged entry nozzle, schematically;
FIG. 2A illustrates a longitudinal section of one example of a related art submerged
entry nozzle;
FIG. 2B illustrates a side sectional view of FIG. 2A;
FIG. 3 illustrates an enlarged view of "A" part in FIG. 2A;

FIG. 4A illustrates a longitudinal sectional view of another example of related art
submerged entry nozzle;
FIG. 4B illustrates a side sectional view of FIG. 4A;
FIG. 5A illustrates a longitudinal sectional view of a submerged entry nozzle in
accordance with a preferred embodiment of the present invention;
FIG. 5B illustrates a section across a line I-I in FIG. 5A;
FIG. 6A illustrates a section across a line II-II in FIG. 5A;
FIG. 6B illustrates a section across a line VI-VI in FIG. 5A;
FIG. 6C illustrates a section across a line VH-VII in FIG. 5A; and
FIG. 6D illustrates a section across a line VIII-VIII in FIG. 5A.
Best Mode for Carrying Out the Invention
To achieve the object of the present invention, the present invention suggests a
submerged entry nozzle for continuous casting including an inlet member of a refractory
material with a trumpet shaped inlet, and other portions including an upper part continuous
from the inlet, having a flow passage section of an elongated hole form with a great long side
distance and a small short side distance in overall, with a fixed sectional area, a transit part
continuous from the upper part, having a nozzle wall thickness which becomes the thinner
gradually as it goes toward an outlet of the nozzle the farther, and a flow passage section of
an elongated hole form with a short side distance which becomes the greater as it goes toward
the outlet of the nozzle the farther, and a long side distance which becomes the smaller as it

goes toward the outlet of the nozzle the farther, while an area of the flow passage section is
kept constant, and a lower part continuous from the transit part, having a nozzle wall
thickness which has almost no change as it goes toward the outlet, a short side distance which
increases moderately compared to the short side distance increase in the transit part, and
symmetric outlets with reference to a splitter at an end portion of the lower part for guiding a
molten metal flow into a mold, wherein an area of the flow passage section increases
gradually within a range of 5% with reference to an area of a flow passage section at a
location where the flow passage starts at an end of the inlet in the upper part as it goes toward
the outlets the farmer until the splitter starts, where the flow passage sectional area restores to
the area the same with the reference area until the outlets terminate.
The preferred embodiment of the present invention will be described with reference
to FIGS. 5A-6D.
FIG. 5A illustrates a longitudinal sectional view of a submerged entry nozzle in
accordance with a preferred embodiment of the present invention, FIG. 5B illustrates a
section across a line I-I in FIG. 5A, and FIGS. 6A, 6B, 6C, and 6D illustrate sections across
lines II-II, VI-VI, VII-VII, and VIII-VIII in FIG. 5A.
The submerged entry nozzle for continuous casting in accordance with a preferred
embodiment of the present invention comprises a body 10 of a cylindrical tube including an
upper part 31 having a flow passage section 37 of an elongated hole form with a great short
side distance 'e', and a small long side distance T on the whole, a transit part 32 having a

nozzle wall which becomes the thinner as it goes toward the outlet the farther, and a flow
passage section 37 of an elongated hole form with a short side distance which becomes
gradually longer as it goes toward the outlet the farther, and a long side distance which
becomes gradually shorter as it goes toward the outlet the farther, and a lower part having
almost no wall thickness change, and a short side distance 'e' which increases moderately
compared to the short side distance 'e' increase of the transit part 32.
In an upper part 31 of a body 10 of the submerged entry nozzle in accordance with a
preferred embodiment of the present invention, there is an inlet member 30 of a refractory
material having a trumpet shaped inlet 30a.
Since a tundish for supplying molten metal to the submerged entry nozzle has a
circular flow passage section, while the nozzle has an elongated hole form of flow passage
section, the inlet 30a has a circular section for smooth flow passage connection between the
tundish and the submerged entry nozzle.
Accordingly, of the flow passage section of the inlet 30a, while a top part has a
circular flow passage section having a diameter the same with the flow passage section of the
tundish, a bottom part has a flow passage section gradually converged from the flow passage
section of the top part into a circular flow passage section having a diameter the same with
the long side distance 'f' of the flow passage section 37 of the upper part 31.
Though the inlet member 30 of a refractory material having such an inlet 30a can be
fabricated as one unit with the body 10, since formation of the submerged entry nozzle is

difficult in this case, it is preferable mat the inlet member 30 is fabricated as a separate piece,
and fitted to an inlet side of the submerged entry nozzle.
The flow passage section 37 of the upper part 31 is symmetry with respect to a
sectional plane passing a middle of the long side, and a sectional plane passing a middle of
the short side.
In this instance, the long side of the flow passage section 37 of the upper part 31 is
straight, and the short side thereof is curved, to form a "track" type elongated section.
The upper part 31 having the track type elongated section falls on sections across a
line III-III to a line IV-IV, in which the flow passage sectional area has no change.
Of the flow passage section 37, a ratio of the short side distance 'e' to the long side
distance 'f' is made to be within a range of 1.1 ~ 4.0 in a portion except the trumpet shaped
inlet 30a.
In the meantime, alike the flow passage section 37 of the upper part 31, though the
transit part 32 has a flow passage section with straight long sides and curved short sides, the
short side distance 'e' of the flow passage section 38 of the transit part 32 increases, and the
long side distance 'f' of the flow passage section 38 of the transit part 32 decreases, to form a
"slot" type elongated hole longer than the flow passage section 37 of the upper part 31.
Moreover, though a sectional area of the flow passage section 38 of the transit part
32 (sections from IV-IV line to V-V line) has no change, the transit part 32 has a short side
inside wall 32a or 32b sloped by a slope angle a of 5.0° - 20.0° to a vertical line, and a long

side inside wall 32c or 32d sloped by a slope angle β of 1.0° ~ 8.0° to a vertical line.
At an end of the lower part 33, there are outlets 35 and 36 for guiding molten metal
flow into the mold, and a splitter 34 at a middle thereof for making the molten metal flow
into the mold through the outlets 35, and 36 symmetry.
Moreover, the lower part 33 has a short side inside wall 33a, or 33b sloped by a slope
angle y in a range of 2 ~ 20° to the vertical line which is smaller than the slope angle α of the
short side inside wall 32a, or 32b of the transit part 32, and a long side inside wall 33c, or 33d
having a slope angle to the vertical line formed the smallest possible, preferably 0°.
According to this, the lower part 33 has a flow passage sectional area increasing
gradually within 5% of a flow passage sectional area (called as "reference area") of the
section across the line III-III until the splitter 34 starts where the flow passage sectional area
is restored to the reference area until the ends of the outlets 35, and 36.
That is, a total area of the flow passage sections 39a, and 39b is reduced to 90% of
the reference area in a section the splitter starts due to the splitter 34, and thereafter, the total
area of the flow passage sections 39a, and 39b increases gradually because of the slope angles
of the inside walls 33a, 33b, 33c, and 33d of the lower part 33 to the vertical line.
Though there can be variation of the areas of the flow passage sections of the upper
part 31, the transit part 32, and the ends of the outlets 35, and 36 within a 1 -2 % range,
which can occur from an error between the steps of design and fabrication, because the
variation of 1 ~ 2% is very small, the flow passage sectional areas of the upper part 31 and

the transit part 32 have no change, actually.
Moreover, the splitter 34 has a round portion 34a of a predetermined curvature at a
top, a portion from the round portion to a middle portion thereof in a length direction having
no slope, and a portion under the middle portion having a slope in an oudet direction of the
nozzle.
Particularly, the splitter 34 has an angle θ in a range of 2 ~ 20° to the vertical line,
and preferably 2~5°.
The submerged entry nozzle configured thus has a minimum flow passage sectional
area not below 90%, and a maximum flow passage sectional area not over 105%, of a
reference area, a flow passage sectional area at a location where the inlet member ends.
The action and advantages of the submerged entry nozzle of the present invention
will be described.
The upper part has no change in sectional area except the sectional area change in a
section starting from the trumpet form of inlet 30a to a location connected to the track type
flow passage section 37.
That is, the upper part 31 has no, or minimum change of the short side distance 'e'
and the long side distance 'f', with consequential no change of a flow speed and a pressure of
the molten metal, thereby providing stable flow of the molten metal.
Moreover, if the ratio of the short side distance 'e' to the long side distance 'f' of the
flow passage section is below 1.1, leading to have a form of the flow passage section 37 close

to a circle, and a uniform flow of the molten metal can not be maintained if the ratio is greater
than 4.0, it is preferable that the ratio of the short side distance 'e' to the long side distance 'f'
of the flow passage section 37 of the upper part 31 is within a range of 1.1 ~ 4.0.
Since the transit part 32 has the short side distance 'e' increased and long side
distance 'f' decreased while the area of the flow passage section 38 has no change, leading to
have a more elongated form compared to the flow passage section 37 of the upper part 31, in
a state a sectional area of the flow passage section 38 has no change, the flow speed and
pressure of the molten metal flowing through the transit part 32 have almost no change, to
provide a stable molten metal flow.
Along with this, the transit part 32 has wall thickness which becomes the thinner as it
goes toward the outlet the farther, so as to be consistent with a form of the transit part 32 in
which the short side distance 'e' increases gradually, and the long side distance 'f' decreases
gradually.
If the nozzle wall thickness in a short side distance 'e' direction and the nozzle wall
thickness in a long side distance 'f direction have an excessive difference, stress is
concentrated at this portion, making security of the nozzle poor.
Therefore, it is preferable that the nozzle wall thickness of the transit part 32
becomes the thinner gradually as it goes toward the outlet the farther in conformity to the
changes of the short side distance 'e', and the long side distance 'f' of the flow passage
section 38.

Moreover, because a stable molten metal flow can not be obtained if the long sides of
the flow passage sections of the upper part 31 and the transit part 32 are curved, to cause a
molten metal flow speed difference between a middle and opposite ends of the long side, it is
preferable that the molten metal flow in the nozzle is made stable by forming the long sides
of the flow passage sections of the upper part 31 and the transit part 32 straight, and short
sides thereof to be curved with predetermined curvatures, to form the track type and slot type
flow passage sections, respectively.
The lower part 33 has an area of each of the flow passage section 39a, or 39b
increasing gradually as it goes toward the end of the oudet 35, or 36 the farther until the area
is restored to the same with the reference area except one time of the sectional area reduction
at a portion the splitter 34 starts.
Moreover, since the lower part 33 has a short side inside wall 33a, or 33b sloped by a
slope angle γ in a range of 2 ~ 20° to the vertical line which is smaller than the slope angle α
of the short side inside wall of the transit part 32, the lower part 33 has almost no change of a
nozzle thickness, and since the lower part 33 has the flow passage section 39a, or 39b of
which short side distance 'e' increases moderately compared to the transit part 32, the short
side distance 'e' of the flow passage section 39a, or 39b of the lower part 33 has the slot type
section elongated more than the short side distance 'e' of the flow passage section 38 of the
transit part 32.
Accordingly, though the flow passage section 39a, or 39b of the lower part 33 has the

slot type section elongated more than the flow passage section 38 of the transit part 32,
because the sectional area of the flow passage section 39a, and 39b has almost no change,
with almost no change of the flow speed and pressure of the molten metal flowing through an
inside of the lower part 33, a stable molten metal flow can be obtained.
The splitter 34 splits the molten metal at a predetermined angle.
Particularly, the round portion 34a of the top of the splitter 34 prevents the molten
metal from spraying to an outside of the mold at an initial stage of the casting as the molten
metal hits a top surface of the splitter 34.
If the angle 9 of the splitter 34 to the vertical line is below 2°, spread of the molten
metal can be difficult, and, if the angle 9 is greater man 20°, the molten metal may hit the
inside wall of the mold strongly, affecting formation of solidifying cells, and stability of the
molten metal surface.
Accordingly, the angle θ of the splitter 34 to the vertical line is maintained to be
within a range of 2 ~ 20°, for preventing above problems.
Thus, the present invention can solve the related art problems caused by rapid change
of the flow speed and pressure of the molten metal, because the submerged entry nozzle of
the present invention has no rapid change of a flow passage sectional area inside of the
submerged entry nozzle, with no rapid change of the flow speed and the pressure.
That is, by maintaining changes of sectional area starting from the trumpet type inlet
30a to the ends of the outlet 35, and 36 to be within a range of 90 - 105%, the submerged

entry nozzle of the present invention can minimize differences of the flow speeds and
pressures between a central flow 51 and inside wall side flows 52 of an inside of the nozzle,
and prevent non-uniform flow of the molten metal at the time of splitting the molten metal by
the splitter 34, enabling to obtain a stable molten metal flow.
Accordingly, the present invention has solved the problems in the related art in which
solidification of the molten metal is delayed within the mold locally, and a thickness of the
solidified cell is not uniform, to cause longitudinal cracks in a surface of the slab.
Moreover, the submerged entry nozzle of the present invention permits to have a
stable molten metal surface as well as easy floatation of the inclusions, enabling an easy
separation of the inclusions.
That is, if the molten metal flow in the mold is not stable, and fluctuation of the
molten metal surface is heavy, or there is a vortex of the molten metal, the inclusions can not
float up from an inside of the mold, or mold powder can be entrained into the molten metal,
since the submerged entry nozzle of the present invention has a stable molten metal flow,
above problems do not occur.
In the meantime, a result of test for verifying effects of the present invention will be
described.
In order to verify effects of the present invention, three kinds of submerged entry
nozzles, i.e., the submerged entry nozzle in accordance with a preferred embodiment of the
present invention shown in FIGS. 5A and 5B, and the related art submerged nozzles (the

related arts 1 and 2), are fabricated of acryl in 1:1 models, and flows in molds and height
differences caused by fluctuation of molten metal surfaces are analyzed by means of water
model tests, to obtain results as shown in table 1 below.
The water model test is a testing method for understanding flow characteristics of a
fluid inside of the nozzle and the mold by fabricating the submerged entry nozzles and the
molds of acryl, and by using an experiment the same with actual casting of the molten metal
by using water instead of the molten metal.

Referring to table 1, as a result of comparison of the submerged entry nozzle of the
present invention having outlets 35, and 36 each with a diverging angle to the related art 1
and 2 submerged entry nozzles, it can be known that molten metal surface height differences
of the related art 1 and 2 submerged entry nozzles are greater than a molten metal surface
height difference of the submerged entry nozzle of the present invention.

That is, though the submerged entry nozzle of the present invention has a small
molten metal surface height difference at a distance from an inside wall of short side of a
mold, the related art 1 and 2 submerged entry nozzles have a molten metal surface height
difference at a distance from an inside wall of short side of a mold greater than the present
invention.
Particularly, it can be noted that the related art 1 and 2 submerged entry nozzles have
the molten metal surface height difference at a short distance from an inside wall of short side
of a mold greater than the present invention, representing that the related art 1 and 2
submerged entry nozzles have a molten metal surface height greater than the present
invention.
This implies that an area of the reversed flow formed by the molten metal flow S1
discharged along the inside wall of the submerged entry nozzle of the present invention is
smaller than the cases of the related art 1, and 2. According to this, the present invention
minimizes the molten metal surface difference, to enable secure operation.
Industrial Applicability
The submerged entry nozzle of the present invention minimizes flow speed and
pressure changes inside of the submerged entry nozzle in continuous casting, to suppress
occurrence of stagnant area of the molten metal, to form a symmetric flow of the molten
metal within the mold.
According to this, the submerged entry nozzle of the present invention stabilizes the

molten metal surface inside of the mold, and reduces a height difference caused by
fluctuation of the molten metal surface, permitting to produce good quality cast having a
uniform solidified cells. According to mis, the present invention has very high industrial
applicability.


WE CLAIM :
1. A submerged entry nozzle for continuous casting comprising:
an inlet member of a refractory material with a trumpet shaped inlet, and
other portions including;
an upper part (31) continuous from the inlet, having a flow passage section of an
elongated hole form with a great long side distance (e) and a small short side distance (f) in
overall, with a fixed sectional area,
a transit part (32) continuous from the upper part (31), having a nozzle wall thickness
which becomes the thinner gradually as it goes toward an outlet of the nozzle the farther, and
a flow passage section of an elongated hole form with a short side distance (e) which
becomes the greater as it goes toward the outlet of the nozzle the farther, and a long side
distance (f) which becomes the smaller as it goes toward the outlet of the nozzle the farther,
while an area of the flow passage section is kept constant, and
a lower part (33) continuous from the transit part (32), having a nozzle wall thickness
which has almost no change as it goes toward the outlet, a short side distance which increases
moderately compared to the short side distance increase in the transit part, and symmetric
outlets with reference to a splitter (34) at an end portion of the lower part (33) for guiding a
molten metal flow into a mold, wherein an area of the flow passage section increases
gradually within a range of 5% with reference to an area of a flow passage section at a

location where the flow passage starts at an end of the inlet in the upper part as it goes toward
the outlets the farther until the splitter starts, where the flow passage sectional area restores to
the area the same with the reference area until the outlets terminate.
2. The submerged entry nozzle as claimed in claim 1, wherein the upper part (31) has
a ratio of the short side distance to the long side distance of 1.1 ~ 4.0.
3. The submerged entry nozzle as claimed in claim 1 or 2, wherein the flow passage
section of the upper part (31) comprises a straight long side and a curved short side with a
fixed curvature.
4. The submerged entry nozzle as claimed in claim 1, wherein the flow passage
section of the transit part (32) comprises a straight long side and a curved short side with a
fixed curvature, wherein the short side distance (f) increases, and the long side distance (e)
decreases, compared to the flow passage section of the upper part.
5. The submerged entry nozzle as claimed in claim 1 or 4, wherein the transit part
(32) comprises;
a long side inside wall sloped by an angle of 1.0 ~ 8.0° to a vertical line, and
a short side inside wall sloped by an angle of 5.0 ~ 20.0° to a vertical line.

6. The submerged entry nozzle as claimed in claim 1, wherein the lower part (33)
comprises a short side inside wall sloped by 2 ~ 20° to a vertical line, which is smaller than
the angle of the slope of the short side inside wall of the transit part.
7. The submerged entry nozzle as claimed in claim 1, wherein the splitter (34)
comprises a short side inside wall sloped by a predetermined angle to a vertical line
substantially starting from a middle of a length thereof in a direction of the outlet.
8. The submerged entry nozzle as claimed in claim 7, wherein the splitter (34)
comprises a lower portion sloped by an angle in a range of 2 - 20° to the vertical line.
9. The submerged entry nozzle as claimed in claim 1, wherein the inlet member of a
refractory having an inlet is fabricated as a separate piece, and fitted to an inlet side of the
nozzle.


A submerged entry nozzle is disclosed. Said submerged entry nozzle comprises an
inlet member of a refractory material with a trumpet shaped inlet, and other portions
including an upper part (31) continuous from the inlet, having a flow passage section of an
elongated hole form with a great long side distance (e) and a small short side distance (f) in
overall, with a fixed sectional area, a transit part (32) continuous from the upper part (31),
having a nozzle wall thickness which becomes the thinner gradually as it goes toward an
outlet of the nozzle the farmer, and a flow passage section of an elongated hole form with a
short side distance (e) which becomes the greater as it goes toward the outlet of the nozzle the
farther, and a long side distance (f) which becomes the smaller as it goes toward the outlet of
the nozzle the farther, while an area of the flow passage section is kept constant, and a lower
part (33) continuous from the transit part (32), having a nozzle wall thickness which has
almost no change as it goes toward the outlet, a short side distance which increases
moderately compared to the short side distance increase in the transit part, and symmetric
outlets with reference to a splitter (34) at an end portion of the lower part (33) for guiding a
molten metal flow into a mold.

Documents:

00327-kolnp-2006-abstract.pdf

00327-kolnp-2006-claims.pdf

00327-kolnp-2006-description complete.pdf

00327-kolnp-2006-drawings.pdf

00327-kolnp-2006-form-1.pdf

00327-kolnp-2006-form-3.pdf

00327-kolnp-2006-form-5.pdf

00327-kolnp-2006-international publication.pdf

327-KOLNP-2006-ABSTRACT.pdf

327-KOLNP-2006-AMENDED CLAIMS.pdf

327-KOLNP-2006-AMENDED PAGES OF SPECIFICATION.pdf

327-kolnp-2006-assignment.pdf

327-kolnp-2006-assignment1.1.pdf

327-KOLNP-2006-CANCELLED PAGES.pdf

327-KOLNP-2006-CORRESPONDENCE-1.1.pdf

327-kolnp-2006-correspondence.pdf

327-KOLNP-2006-CORRESPONDENCE1.2.pdf

327-kolnp-2006-correspondence1.3.pdf

327-KOLNP-2006-DRAWINGS.pdf

327-kolnp-2006-examination report.pdf

327-KOLNP-2006-FORM 1.pdf

327-kolnp-2006-form 18.1.pdf

327-kolnp-2006-form 18.pdf

327-KOLNP-2006-FORM 2.pdf

327-kolnp-2006-form 3.1.pdf

327-KOLNP-2006-FORM 3.pdf

327-kolnp-2006-form 5.pdf

327-KOLNP-2006-FORM-27.pdf

327-kolnp-2006-gpa.pdf

327-kolnp-2006-gpa1.1.pdf

327-kolnp-2006-granted-abstract.pdf

327-kolnp-2006-granted-claims.pdf

327-kolnp-2006-granted-description (complete).pdf

327-kolnp-2006-granted-drawings.pdf

327-kolnp-2006-granted-form 1.pdf

327-kolnp-2006-granted-form 2.pdf

327-kolnp-2006-granted-specification.pdf

327-kolnp-2006-intenational publication.pdf

327-kolnp-2006-international search report.pdf

327-kolnp-2006-others.pdf

327-kolnp-2006-pct priority document notification.pdf

327-kolnp-2006-pct request form.pdf

327-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

327-kolnp-2006-reply to examination report1.1.pdf

327-KOLNP-2006-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

327-kolnp-2006-translated copy of priority document1.1.pdf

abstract-00327-kolnp-2006.jpg


Patent Number 249001
Indian Patent Application Number 327/KOLNP/2006
PG Journal Number 38/2011
Publication Date 23-Sep-2011
Grant Date 20-Sep-2011
Date of Filing 15-Feb-2006
Name of Patentee CHOSUN REFRACTORIES CO., LTD.
Applicant Address TAEINDONG 1657-9, KWANGYANG-SI, JEOLLANAM-DO
Inventors:
# Inventor's Name Inventor's Address
1 YANG, KEE DEOK 3-307, IN HWA APT., DUKYANG-DONG, BUK-GU, POHANG-SI, GYEONGSANGBUK-DO
2 SHIN, YOUN CHUL 114-607, YI-DONG HYUNDAI HOME-TOWN, DAEJAM-DONG, NAM-GU, POHANG-SI, GYEONGSANGBUK-DO
PCT International Classification Number B22D 41/50
PCT International Application Number PCT/KR2004/002160
PCT International Filing date 2004-08-27
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10-2003-0059504 2003-08-27 Republic of Korea
2 10-2004-0067170 2004-08-25 Republic of Korea