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Description
SUBMERGED ENTRY NOZZLE FOR CONTINUOUS CASTING
Technical Field
[1] The present invention relates to a submerged entry nozzle for continuous casting,
and more particularly, to a submerged entry nozzle for continuous casting, in which a
section of a portion of a nozzle is formed to have a flower pattern for preventing
molten steel passing through the submerged entry nozzle from flowing unevenly, and
inclusions from attaching to the submerged entry nozzle.
Background Art
[2] In general, in the continuous casting, molten steel is cast from a ladle to a mold
through a tundish continuously, and the molten steel is solidified, to form a cast piece.
[3] FIG. 1 illustrates a related art continuous casting from a tundish to a mold
schematically, wherein, in the continuous casting from the tundish to the mold, molten
steel is supplied from a ladle 1 to the tundish 2 with a flow rate thereof regulated by a
sliding plate 3 under the tundish 2, and cast into the mold 7 through a submerged entry
nozzle 6.
[4] Referring to FIG. 2, in the sliding plate 3, there are an upper plate 3a, a middle plate
3b, and a lower plate 3c. Over the upper plate 3a, there is an upper nozzle 4, and under
the lower plate 3c, there is the submerged entry nozzle 6. The middle plate 3b moves in
left/right directions to vary an aperture that enables the upper nozzle 4 and the
submerged entry nozzle 6 in communication, thereby regulating a rate of supply of the
molten steel from the tundish 2 toward the submerged entry nozzle 6.
[51 According to this, the molten steel being supplied toward the submerged entry
nozzle 6 through the sliding plate 3 is given a rotating force as the molten steel hits
onto an inside surface of the submerged entry nozzle 6 continuously, to cause uneven
flow, and vortex, of the molten steel, leading a splash to take place.
[6] The splash causes a non-uniform molten steel flow in the nozzle, resulting in
attachment of a large amount of inclusions to the inside surface of the submerged entry
nozzle 6. The inclusions clogs an inside of the submerged entry nozzle 6, not only to
cause non-uniform flow rate, or flow speed, and to form a non-smooth cast piece, or an
instable molted steel surface, leading to reduction of a rate of casting, but also, when
intensive, to cause a serious problem of stopping the casting, thereby dropping pro-
ductivity, and impairing a quality at the end.
[7] Referring to FIG. 2, as a related art method for preventing the molten steel from
flowing unevenly, or preventing the inclusions from attaching to an inside of the
nozzle, the submerged entry nozzle 10 is formed with a predetermined size of stepped

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portion 11 inside of the nozzle 10, so that a flow speed of the molten steel increases as
the molten steel passes through the nozzle having a size become smaller by the stepped
portion 11, to suppress the uneven flow of the molten steel and the attachment of the
inclusions.
[8] However, with such a submerged entry nozzle 10, only an effect can be expected, in
which molten steel flows at left, right side exits 12, and 12 become more or less
uniform due to the flow speed increase of the molten steel, but perfect elimination of
uneven flow of the molten steel in the nozzle is not possible. On the contrary, the
molten steel stagnates at the stepped portion 11 to form a stagnated portion, to
accumulate the inclusions thereon, and to spread the accumulation of the inclusions to
neighboring regions, causing the uneven flow of the molten steel and attachment of the
inclusions again, at the end.
[9] In the meantime, referring to FIG. 3, as another related art nozzle for preventing the
molten steel from flowing unevenly, or the inclusions from attaching, "a collector
nozzle or submerged entry nozzle for continuous casting" is known.
[10] The submerged entry nozzle 20 has a portion 'p' with a flower patterned section for
suppressing the uneven flow of the molten steel by a centripetal force acting toward a
center of the flower pattern to distribute the molten steel to the exits 22 in a lower side
of the submerged entry nozzle 10, and, along with this, a stepped portion 21 under the
portion 'p' with a flower patterned section, having an inside diameter smaller than an
inside diameter of the portion 'p' with a flower patterned section, for increasing the
flow speed of the molten steel having passed through the portion 'p' with a flower
patterned section, to suppress the attachment of inclusions on an inside of the nozzle.
[11] However, referring to FIG. 4, alike the foregoing submerged entry nozzle 10, the
submerged entry nozzle 20 has limitation in perfect elimination of the uneven flow of
the molten steel, because the molten steel made to flow unevenly by the sliding plate 3
enters into circular recesses on a side of the portion 'p' with a flower patterned section
having the molten steel deflected thereto while excluding some of the circular recesses
23, resulting in failure in solving the problem of accumulation of the inclusions on the
stepped portion 21 and spreading of the accumulation to neighboring regions, still
Disclosure of Invention
Technical Problem
[12] The object of the present invention is to provide a submerged entry nozzle having a
flower patterned portion for preventing molten steel from flowing unevenly and
forming vortexes, and inclusions from attaching to an inside wall of the nozzle during
the molten steel passes through the submerged entry nozzle.
Technical Solution

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[13] The object of the present invention can be achieved by providing a submerged entry
nozzle for continuous casting, having a flower patterned portion with a flower pattern
of radial circular recesses at a portion of the nozzle for preventing molten steel from
flowing unevenly and inclusions from attaching during the molten steel passes through
the nozzle in continuous casting, including an enlarged inside diameter portion having
an inside diameter 1.1-1.5 times greater than an inside diameter of a circle drawn to
pass through innermost tips of the flower pattern, wherein the enlarged inside diameter
portion begins from an end of the flower patterned portion which is spaced a pre-
determined distance away from a top of the nozzle.
[14] Preferably, the distance is 50mm ~ 300mm.
[15] Preferably, the flower patterned portion has a length of 50mm ~ 400mm.
[16] The flower patterned portion may include tapered portions at both ends each with
an inside diameter which becomes the greater as it goes toward the end the more.
[17] The submerged entry nozzle may further include a reduced inside diameter portion
which is curved such that an inside diameter thereof becomes the greater as it goes
toward both ends thereof the more.
[18] Preferably, the circular recesses of the flower pattern are formed oppositely, with an
even number.
Advantageous Effects
[19] The submerged entry nozzle of the present invention prevents the molten steel from
flowing unevenly and the inclusions from attaching effectively, thereby improving pro-
cessability of the continuous casting, and stabilizing a surface of the molten steel in a
mold to improve a quality of steel by forming a flower patterned portion at a position a
predetermined distance away from a top of the nozzle, so that the molten steel passing
through the nozzle gathers to an inner portion of the nozzle naturally, enabling uniform
entrance of the molten steel into the flower patterned portion, and forming an enlarged
inside diameter portion having an inside diameter 1.1 to 1.5 times greater than an
inside diameter of the flower patterned portion at an end of the flower patterned
portion to increase a flow speed of the molten steel to a proper level.
Brief Description of the Drawings
[20] The accompanying drawings, which are included to provide a further understanding
of the invention, illustrate embodiment(s) of the invention and together with the de-
scription serve to explain the principle of the invention. In the drawings;
[21] FIG. 1 illustrates a related art continuous casting from a tundish to a mold
schematically;
[22] FIG. 2 illustrates a longitudinal section of an exemplary related art submerged entry
nozzle for continuous casting having a stepped portion at an inside;

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[23] FIG. 3 illustrates a longitudinal section of another exemplary related art submerged
entry nozzle for continuous casting, having both a flower patterned section and a
stepped portion at an inside;
[24] FIG. 4 illustrates a cross section of another exemplary related art submerged entry
nozzle for continuous casting, having both a flower patterned section and a stepped
portion at an inside;
[25] FIG. 5 illustrates a longitudinal section of a submerged entry nozzle for continuous
casting in accordance with a preferred embodiment of the present invention; and
[26] FIG. 6 illustrates a flower patterned section of a submerged entry nozzle for
continuous casting in accordance with a preferred embodiment of the present
invention.
Best Mode for Carrying Out the Invention
[27] Reference will now be made in detail to the preferred embodiments of the present
invention, examples of which are illustrated in the accompanying drawings. Wherever
possible, the same reference numbers will be used throughout the drawings to refer to
the same or like parts.
[28] The words used in the specification and claims are required to be interpreted in a
sense meeting technical aspect of the present invention in light of a principle that
concept of the words used in the specification and claims can be defined such that the
inventor can best explain the inventor's invention.
[29] Referring to FIGS. 5 and 6, the submerged entry nozzle 100 for continuous casting
is mounted so as to be in close contact to an underside of the lower plate 3c of the
sliding plate 3 under the tundish 2, and includes a portion 'B' having a flower patterned
section of radial direction circular recesses 103 for preventing the molten steel from
flowing unevenly and the inclusions from attaching to the inside of the submerged
entry nozzle 100 during the molten steel passes through the submerged entry nozzle
100.
[30] Since the flower pattern of the present invention is identical to the flower pattern in
the related art, detailed description of which will be omitted.
[31] In the present invention, to prevent the molten steel from flowing unevenly in the
submerged entry nozzle 100 effectively, the flower patterned portion 'B' is formed at a
position a predetermined distance 'A' away from a top of the nozzle. If the flower
patterned portion 'B' is formed at the position a predetermined distance 'A' away from
the top of the nozzle, the failure in perfect elimination of the uneven flow of the molten
steel can be prevented, which is caused by the uneven flow of the molten steel to one
side of an inside of the nozzle in a process the molten steel passes through the sliding
plate 3, and consequential initial entrance into one side of the flower pattern.

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[32] That is, the molten steel introduced into the top of the submerged entry nozzle 100
naturally gathers to an inner portion of the nozzle as the molten steel passes through
the predetermined distance 'A' such that the molten steel gathers over entire region of
the flower pattern uniformly at the time the molten steel is passing through the flower
patterned portion 'B', which suppresses the uneven flow of the molten steel at the
flower patterned portion 'B'.
[33] Table 1

A distance from a top of the nozzle

Below 50mm 50 ~ 300mm Over
300mm
A number of vortexes Many small ordinary
A surface state of molten steel in a
mold ordinary good unstable
Uneven flow of molten steel
discharged from left/right side exits
(kg/sec) 1.27 0.24 1.42
[34J Table 1 shows a result of test of a vortex state at the top of the nozzle, a surface
state of the molten steel in a mold, and a difference of molten steel masses discharged
from the left/right side exits per second of submerged entry nozzles respectively
having the flower patterned portions formed at distances varied from the top of
respective submerged entry nozzles.
[35] As can be known from table 1, if the flower patterned portion 'B' is close to the top
of the submerged entry nozzle below 50mm, or far therefrom over 300mm, the vortex
of the molten steel is excessive, to cause heavy uneven flow of the molten steel.
[36] Accordingly, it can be known that the flower patterned portion 'B' is formed at a
distance of 50mm ~ 300mm from the top of the submerged entry nozzle 6.
[37] Along with this, it becomes known from a repetition of test in which a length of the
flower patterned portion 'B' is varied that the best result is obtainable when the flower
patterned portion 'B' is formed over a length of 50mm ~ 400mm.
[38] This is because the uneven flow of the molten steel can not be eliminated perfectly
during the molten steel passes through the flower patterned portion 'B' due to too short
the length of the flower patterned portion 'B' if the flower patterned portion 'B' is
formed shorter than 50mm, and, if the flower patterned portion 'B' is formed longer
than 400mm, because a distance between a lower end of the flower patterned portion
'B' and the exits 120 of the submerged entry nozzle 100 becomes too short, leading the
molten steel passed through the flower patterned portion 'B' to have a speed faster than

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a proper speed discharged at a fast speed from the exits 120, resulting in a surface of
the molten steel in a mold unstable.
[39] In the meantime, the submerged entry nozzle 6 of the present invention includes an
enlarged inside diameter portion 'C having an inside diameter d2 greater than an inside
diameter dl of a circle passing through inner most tips of the flower pattern starting
from an end of the flower patterned portion 'B'.
[40] If the enlarged inside diameter portion 'C has an inside diameter d2 the same or
smaller than the inside diameter dl of the flower pattern, a flow speed of the molten
steel passed through the portion 'C becomes faster, leading the surface state of the
molten steel in the mold unstable, and the inclusions stuck to the inside surface of the
nozzle due sudden increase of the speed of the molten steel to form a stagnated region
of the molten steel.
[41] On the other hand, if the enlarged inside diameter portion 'C has an inside diameter
d2 greater than the inside diameter dl of the flower pattern over a proper range, the
inclusions are liable to stick to the inside surface of the nozzle due to sudden reduction
of the speed of the molten steel.
[42] Therefore, it is required that the enlarged inside diameter portion 'C has a proper
range of diameter so that the flow speed of the molten steel is not reduced, suddenly.
Through a plurality of repetitive tests, the inventor can obtain a result that the flow of
the molten steel is the most stable and the attachment of the inclusions are minimum in
a case the inside diameter of the enlarged inside diameter portion 'C is 1.1 to 1.5 times
greater than the inside diameter dl of the inner most tips of the flow pattern.
[43] In the meantime, it is preferable that both ends of the flower patterned portion is
tapered with an inside diameter which becomes the greater as it goes toward the end
the more. The tapered portions 103 at both ends of the flower patterned portion 'B'
make the molten steel to gather to a center, to eliminate the vortex and the uneven flow
of the molten steel more effectively, and to prevent the speed of the molten steel from
the flower patterned portion 'B' from reducing/increasing suddenly, enabling to
maintain a stable flow of the molten steel.
[44] According to the present invention, on a lower side of the nozzle where the enlarged
inside diameter portion 'C ends, a reduced inside diameter portion 'D' having an inside
diameter d3 smaller than the enlarged inside diameter portion 'C may be provided.
[45] Because the molten steel passed through the flower patterned inside diameter
portion 'B' and the enlarged inside diameter portion 'C in succession gathers to the
center of the nozzle, with an appropriate increase of the flow speed, the reduced inside
diameter portion 'D' removes the uneven flow of the molten steel for the second time,
to remove even fine uneven flow perfectly, which is removed as the molten steel
passes through the flower patterned portion 'B' and the enlarged inside diameter

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portion 'C for the first time.
[46] In this case, it is preferable that the reduced inside diameter portion 'D' is curved
such that an inside diameter thereof becomes the greater as it goes toward both ends
thereof the more, to enable the molten steel to enter the reduced inside diameter
portion 'D' from the enlarged inside diameter portion 'C smoothly, to prevent a molten
steel stagnation, with consequential prevention of attachment of the inclusions at the
entrance to the reduced inside diameter portion 'D'.
[47] A plurality of the reduced inside diameter portions 'D' may be formed as required.
[48] In the meantime, it is preferable that the circular recesses 103 of the flower pattern
at the flower patterned portion 'B' are formed oppositely, with an even number.
[49] If the circular recesses 103 are formed with an odd number, unable to arrange the
circular recesses 103 over the opposite exits 120 at the lower end of the submerged
entry nozzle 6, the molten steel can not flow from the lower end of the circular recess
103 to the exits 120 smoothly, but forms vortex at an entrance to the exit 120 as the
flowing molten steel collides. The vortex causes non-smooth discharge of the molten
steel, to increase uneven flow, with formation of the stagnation, that is liable to cause
attachment of the inclusions.
[50] Therefore, the formation of the flower pattern 103 oppositely with an even number
prevents above problem effectively.
[51] Table 2

Number of
measurement casting time
period
(min.) Thickness of attached inclusions (mm)

Position 'a' Position V Position 'c'
The present
invention First 270 2 3 5

Second 285 2 3 5
Comparative
example 1 First 205 5 8 15

Second 235 3 10 15
Comparative
example 2 First 200 2 8 10

Second 235 3 9 12
[52] Table 2 shows a result of comparative tests of attachment of the inclusions to the
submerged entry nozzle 100 of the present invention and the submerged entry nozzle
10 or 20 having the stepped portion 11, or 21 on one side of the inside of the nozzle, or
the flower patterned portion 'P' while varying a position of the measurement.
[53] The comparative example 1 of the test shows a result of test with the related art
submerged entry nozzle 10 (see FIG. 2) having the stepped portion 11 for making the

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inside diameter smaller, and the comparative example 2 of the test shows a result of
test with the related art submerged entry nozzle 20 (see FIGS. 3 and 4) having the
flower patterned portion 'P' and the stepped portion 21.
[54] As can be known from table 2, the inclusions attached to the inside of the
submerged entry nozzle of the present invention is the smallest, indicating that the
submerged entry nozzle of the present invention is more effective in prevention of the
uneven flow of the molten steel and attachment of the inclusions than the related art
submerged entry nozzles 10 and 20.
[55] It will be apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing from the spirit or
scope of the inventions. Thus, it is intended that the present invention covers the modi-
fications and variations of this invention provided they come within the scope of the
appended claims and their equivalents.
Industrial Applicability
[56] The submerged entry nozzle for continuous casting of the present invention has a
significantly high industrial applicability because the even flow of the molten steel that
increases a flow speed of the molten steel appropriately permits to prevent the molten
steel from flowing evenly, and the inclusions from attaching to the inside of the nozzle.

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Claims
[ 1] A submerged entry nozzle for continuous casting, having a flower patterned
portion with a flower pattern of radial circular recesses at a portion of the nozzle
for preventing molten steel from flowing unevenly and inclusions from attaching
during the molten steel passes through the nozzle in continuous casting, the
nozzle comprising:
an enlarged inside diameter portion having an inside diameter 1.1 ~ 1.5 times
greater than an inside diameter of a circle drawn to pass through innermost tips
of the flower pattern,
wherein the enlarged inside diameter portion begins from an end of the flower
patterned portion which is spaced a predetermined distance away from a top of
the nozzle.
[2] The submerged entry nozzle as claimed in claim 1, wherein the distance is 50mm
~ 300mm.
[3] The submerged entry nozzle as claimed in claim 1 or 2, wherein the flower
patterned portion has a length of 50mm ~ 400mm.
[4] The submerged entry nozzle as claimed in claim 1, wherein the flower patterned
portion includes tapered portions at both ends each with an inside diameter
which becomes the greater as it goes toward the end the more.
[5] The submerged entry nozzle as claimed in claim 1, further comprising a reduced
inside diameter portion which is curved such that an inside diameter thereof
becomes the greater as it goes toward both ends thereof the more.
[6] The submerged entry nozzle as claimed in claim 1, wherein the circular recesses
of the flower pattern are formed oppositely, with an even number.

The present invention relates to a submerged entry nozzle for continuous casting, and more particularly, to a submerged entry nozzle (100) for continuous casting, in which a section of a portion of a nozzle is formed to have a flower pattern (103) for preventing molten steel passing through the submerged entry nozzle (100)
from flowing unevenly, and inclusions from attaching to the submerged entry nozzle.
The submerged entry nozzle (100) for continuous casting, having a flower patterned portion (B) with a flower pattern (103) of radial circular recesses at a portion of the nozzle for preventing molten steel from flowing unevenly and inclusions from attaching during the molten steel passes through the nozzle in continuous casting, including an enlarged inside diameter portion (C) having an inside diameter 1.1 1.5 times greater than an inside diameter of a circle drawn to pass through innermost tips of the flower pattern (103), wherein the enlarged inside diameter portion (C) begins from an end
of the flower patterned portion (B) which is spaced a predetermined distance away
from a top of the nozzle, thereby preventing the molten steel from flowing unevenly
and inclusions from attaching to an inside of the nozzle, enhancing productivity of the
continuous casting and stabilizing a surface of the molten steel in a mold to improve
a quality of steel.