Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTION
The present invention relates to a pouring nozzle for a
strand casting devic0 and to an in~ermediate container provided
therewithO
Strand casting device are known in the art in which an
intermediate container or a distribu~or has a pouring opening
provided with a pouring sleeve of reEractory material.
In the known intermediate containers, which sometimes are
controlled by a slider, in the event of the open slider there are
always casting di~ficulties, inasmuch as during the beginning of
casting the melt flowing from the ladle into the intermediate
container has a tendency to freeze and block ~he same because o the
initial high temperature losses and impurities located in the
intermediate container from the heating period, These casting
problems cannot be eliminated even in the event that the pouring
sleeve extend somewhat over the bottom of the intermediate container
or the outlet, for example during open castingt is closed by a lead
pl~lg ~
SUMMARY OF THE INVENTION
I provide a pouring nozzle and an intermediate container
therewith, which avoid the disadvantages oE the prior art.
More particularly, I provide a pouring nozzle and an
intermediate container therewith which guarantee a disturbance-free
casting in a casting device.
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In keeping with these objects and with others which will
become apparent hereinafter, one feature of the present invention
resides, briefly stated, in a pouring nozzle or an intermediate
container, in which a pouring nozzle has a body part of refractory
material and an elongated piece also of refractory material
associated with the body part, and means forming a breakage point
between the body part and the elongated piece is provlded at a
height of a bottom of the intermediate container.
When the pouring device and the intermediate container are
designed in accordance with one aspect oE the present inven~ion/
after reaching the desired bath level the body part is separated
from the elongated piece and thereby the opening in the bottom of
the intermediate container i5 released, so that the melt because of
only small heat losses can be discharged unobjectionably and
continuously, free from slag portions or other impurities. The
separated elongated piece floats on the melt and cannot obstruct -the
free running of the melt or affect its chemical composition.
In accordance with another advantageous feature of my
pouring device, the body part and the elongated piece may be formed
as a one-piece member provided with the breakage point. The thus
elongated pouring nozzle can be broken by an iron rod or a coilecl
hoard pipe of a sufficient length through a plug cover hole or
through an opening in a latera] wall of the intermediate container
by a slide pipe.
The breakage point in this one-piece member can be formed
as a ring-shaped groove which reduces the thickness of a ~all of
this one-piece member.
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In accordance with a Eurther advantageous feature of my
pouring device the body part of the pouring nozzle and the elongated
piece are formed as two members, and the breakage point is formed as
a refractory binding medium between these two members.
The refractory binding the medium is selected so that its
heat strength lies in the region o~ the liquefying temperature of a
melt -to be cast. Upon reachiny the predetermined temperature, the
elongated piece releases automatically from the body part of the
pouring nozzle and rises in the melt.
The novel features which are considered characteristic for
the invention are set forth in particular in the appended claims.
The invention itself~ however, both as to its construction and its
method of operation, together with additional objects and advantages
thereoE, will be best understood from the following description of
specific embodiments when read in connection with the accompanying
drawing.
BRIEF DESCRIPTION OE THE DRAWING
Fig. 1 is a view showing a part of a strand testing device
with an intermediate container and a pouring nozzle in accordance
with the present invention;
Fig. 2 is a view showing a pouring nozzle of Fig. 1 on an
enlarged scale; and
Fig. 3 is a view substantially corresponding to the view of
Fig. 2, but showing a further embodiment of the pouring nozzle in
accordance with the present invention.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 shows a portion of a continuous casting device of
conventional construction. A liquid raw steel 10 flows from a
casting ladle 11 to an intermediate container or distributor 12.
From the intermediate container 12, the raw steel flows to a copper
mold (ingot mold). More particularly, the raw steel Elows from the
intermediate container 12 to the mold 16 ~hrough an outlet opening
13 which is closable by an elongated pouring sleeve 14, and through
an opened slider or gate 15 formed, for example, as a three-plate
regulating gate.
The copper mold 16 is arranged exactly vertically and
opened at both its sides. During casting it is closed only at its
opposite side. The melt cools in the mold 16 exactly for so long
that is can form a bearing outer shell. The partially rigidified
strand is removed from the form vertically, horizontally or in a
curved path, in dependence upon the design of the casting device.
The elongated outlet sleeve 14 and also the distributor 12
are composed advantageously of strong alumina-containing refractory
material. The pouring sleeve 14 is composed of a lower part 17 and
an upper part or upper sleeve piece 18, as can be seen from Fig. 2.
They are advantageously Eormed of one piece with one another. The
pouring sleeve 14, at the point of transition between the parts 17
and 18, is formed with a breaking point in form of a groove-shaped
breakage ring 19. The length of the lower portion 17 of the pouring
sleeve 14 substantially corresponds to the known pouring sleeves
whose one end in mounted condition extends advantageously by
substantially 20-30 mm outwardly above the bottom of the
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intermediate container. The entire length of the pouring sleeve 14
which is lengthened in such a manner is adjusted advantageously in
correspondence with the desired bath level height. In practice the
length o~ the upper sleeve piece 18 is considered sufficient to be
equal to appro~lmately 200 mm.
Fig. 3 shows a Çurther embodiment of lengthened pouring
sleeve which is identified here with reference numeral 20. In
contrast -to the above described one-piece sleeve 14, the pouring
sleeve 20 is Eormed of two partsO A lower part 21 and an upper part
or an upper sleeve piece 22 are connected with one another in butt
relationship with the aid of a refractory binding medium 23. This
binding medium 23 forms a breakage point between both part and has a
heat stren~th lying in the region of the liquefaction temperature o~
the melt to be cast. As a result of this, the breakage point is
dissolved only when the desired bath level height is reached in the
intermediate container. A high heat strength of the introduced
binding medium guarantees a longer dwell time of the melt prior to
casting in the intermediate container, so -that undesirable metal
impurities can bubble up in the slag ~one.
As material for the binding medium, hot glue or other
suitable carbon-containing burning-out materials can be usecl, which
upon attaining a predetermined temperature automatically release the
upper sleeve piece 22. An equally good action can also be attained
with the aid of materials which because of their thermal properties
expand under Eire (burning-out) and thrust the upper sleeve piece~
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The above mentioned invention is described exclusively in
connection with a slider-controlled continuous casting device.
~owever, it is to be understood that its Eeatures can be applied
without structural changes, and without affecting the operation,
a]so to devices which operate in open condition.
The present invention can also be used in so-called
multiple-strand devices in which double or triple ingot molds are
assembled in one mold block. In such devices it is possible,
without danger of casting disturbances) to oscillate the molds
assembled in the respective liftiny tables prior to the start of
casting together with one another and also to remove the strands
from the respective block together, inasmuch as the molds in the
inventive device are supplied approximately with synchronization in
a matter of seconds with the same quantities of metal.
The inventive features can also be used in a device of
joint hybrid cast system without diEficulties. Strand casting
devices of conventional types can also use the inventive eatures
regardless of the number of their strands or strand shapes within
the frame of open or slider-regulated casting metho-~s
It will be understood that each of the elements described
above, or two or more together, may also find a useful application
in other types of constructions differing from the types described
above.
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While the invention has been illustrated and described as
embodied in a pouring nozzle ~Eor a strand casting device, it is not
intended to be limited to the details shown, since various
modifications and struc~ural changes may be made without departing
in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully
reveal the gist of the present invention that others can, by
applying current knowledge, readily adapt it for various
applications without omitting features that from the standpoint of
prior art, fa:irly constitute essential characteristics of the
generic or specific aspects of this invention.
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