Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a horizontal continuous casting
process for continuously producing bolts (billets), rolled plates ~cakes),
and bands ~strips) with a vessel receiving molten metal from a furnace,
from which vessel the metal is withdrawn through one or several molds.
The invention also relates to an apparatus or carrying out the process,
nameLy, a vessel having at Least one mold associated therewith.
Continuous casting of metals and metal alloys is known. In the con-
tinuous casting process, the metal is brought to the molten state in a fur-
nace from which the molten metal is discharged into a water-cooled mold,
positioned below the discharge opening of the furnace, and the molten metal
is then withdrawn through the mold to continuously provide the desired use-
ful shape.A further development of this process is afforded in the horizontal
continuous casting using vessels containing molten metal, the metal usually
being added in batches. Such vessels are heated and normally have a relative-
ly large volume capacity, approximately of the order of 1 to 10 t (metric
tons). Most often, the water-cooled graphite mold is flange mounted to the
vessel, the heating of which is particularly effected by means of a ring-
shaped induction heating means. The arrangement of known horizontal con-
tinuous casting units just described thereby ensures that a sufficiently
large quantity of hot metal is available for the casting or drawing operation,
in order to avoid quality-lowering fluctuations of the casting temperature,
or, at least control the casting temperature within narrow limits.
Furthermore, the vessel serves as a buffer means or holding vessel in
order to receive the melting furnace charges, these having a weight of the
order of several tons. Because of this, the level in the vessel changes con-
tinuously and, correspondingly, changes of the metallostatic pressure in the
mold occur. Such pressure fluctuations, however~ are particularly detri-
mental when the process is to be run at high casting or drawing velocities,
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i.e., when the cooling surface of the mold is to be maximally utilized, while
avoiding a gap formation between the mold wall and the resultant shape.
In order to compensate for heat losses, it has been at-tempted to arrange
the induction rings of the aforementioned ring inductors :in sucll a manner,
thcLt the c:irculating metal is brought as close as poss:ible ~o the mold, in
order to achieve there a direct, intensive heat transfer of the heat pro-
vided by the ring inductor. This aim, however, in practice, is hardly attain-
able when using large volume vessels, since in the metal, being a particu-
larly efficient heat conductor, the heat flow is in the direction of the
highest heat content, i.e., the inductively produced heat in the vessel is
directed more radially towards the point at which the metal is received,
rather than to the point from which the metal is withdrawn through the mold,
where it is foremost required.
In order to avoid these drawbacks, it has been proposed to employ small-
er volume, crucible-like vessels having a capacity in the order of several
hundred kg, for example, 200 to 300 kg. These vessels, into which the molten
metal is introduced from above, comprise at a pertaining side a mold stone
having a flange end face for operatively engaging with a mold. No provision
for heating of such low volume crucibles was made. In order to avoid a re-
duction of the temperature in the direction of the mold into the crucibleprovided ahead of the mold, an insulating separating wall can be provided.
A horizontal casting unit equipped in such a manner, however, has to be oper-
ated at a relatively high minimum drawing capacity, in order to avoid metal
solidification (Einfrierungen) at the separating wall on the side of the mold.
Operation with a high drawing capacity, however, is not always desired
since the drawing velocity, which is related to the drawing capacity, repre-
sents a material-specific parameter which materially affects the quality of
the drawn shape or product. Thus, for example, when a high drawing velocity
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produces qualitatively good results using a certain metal, such a
drawing velocity can produce a qualitatively poor product using
another metal or another alloy, i.e., using certain metals or
certain alloys, it may be required to operate at a lower drawing
velocity in order to produce qualitatively high grade products.
Thus, for example, it has been observed that when casting
or drawing brass, the drawing velocity has to be increased as the
copper content increases, due to the increasing conductivity of the
metal and correspondingly increasing recooling. This relation,
however, is contrary to the technical conditions of induction
heated melting furnaces, since the smelting capacity decreases as
the copper content increases. In practice this would lead to a
smelting capacity to be installed which cannot be primarily adapted
in accordance with the desired production, but would have to be
increased corresponding to the requirements of the horizontal
casting unit.
It is an object of the present invention to adapt the
heretofore prevailing drawing velocities for pertaining cross
sections and metals or alloys to desired drawing velocities and to
adapt the apparatus for prior or subsequent operations, for example
smelting furnaces, without concern for metal solidification,
adjacent the mold.
Furthermore, it is an object of this invention to retain,
to the fullest extent, the advantages of a hori~ontal casting unit,
having a furnace-independent mold, with respect to maximal drawing
capacity, utilization or manipulation, and drawing quality.
According to the present in~ention, there is provided an
apparatus for the continuous casting of metals comprising a supply
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chamber, an extension connected to the supply chamber via channels
and changlng lnto a mould connectlon, as well as a core llmiting
the extension to the supply chamber, said core being penetrated by
- channels in the longitudinal direction and in this region by an
induction heating means perpendicular to the channels, the induction
heating means rapidly heating the accelerated metal volume in the
channels in the direction of the mould, wherein the supply chamber
and the extension designed as a discharge chamber open towards the
top are separated from one another merely by the core and are
incorporated with it ln the refractory lining of a common vessel,
the induction heating means being also effective in the supply
chamber outside the region of the channels.
Preferably the induction heating means comprises a winding
core and a winding contained in a through-bore penetrating the core,
and the heating capacity of the induction heating means is change-
able by means of an adjustable transformer as a function of a
temperature measurement in the region of the inlet into the mould.
The vessel preferably has a capacity of approximately 200
kg metal per mould associated therewith and the overall length of
the vessel is approximately 1 meter.
Specific embodiment of the present invention will now be
descrihea with reference to the accompanying drawings, in which:
Figure 1 is a diagrammatical representation, in vertical
section, of a vessel with a mould connection in the region of a
channel for passage
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therethrough, and heating thereof, for the metal volume required for the
drawing operation; and
Figure 2 is a top plan view :in section of the vessel shown in l-:igure 1
at the heigllt o:E the channels.
The process according to the invent:ion is characterized pr:imarily by
guid:ing the amount of metal required :Eor the casting in tl-e direction of the
mold with concomitant induction heating thereof. One feature of the invention
resides therein that continuously only a small metal volume is to be heated,
while, simultaneously, care is being taken that the just heated metal volume
is passed nearly directly to the mold. It is of primary importance that the
heated metal volume is moved quickly and in a manner such that the direction
of motion of the heated metal volume is at least nearly coincidental with the
longitudinal axis of the drawing cross section of the adjacent mold.
The method, accordingly, is to be carried out in a way such that the
direction of the guiding of the heated metal volume is horizontal or at least
nearly horizontal.
In accordance with one preferred embodiment, the guiding of the molten
metal is assisted, in the direction of the mold, by the induction forces.
In accordance with another preferred embodiment, the method is carried
out such that the addition of the molten metal is carried out prior to the
induction assisted guiding.
In accordance with another preferred embodiment3 the induction heating
is controlled in conformity with the temperature determined in the area of
the metal entry into the mold.
The apparatus in accordance with the invention is characterized prim-
arily by a vessel associated with at least one adjacent mold. The vessel
comprises a filling chamber for receiving liquid metal and, spaced apart
therefrom, a discharge chamber in communication with the mold, the filling
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chamber and the discharge chamber being in communication with each other.
In the region of the channels and in the region of the filling and -the dls-
charge chambers, an induction heating means is provided.
In accordatlce with one preferred embodlment of the apparatus in accord-
~mce l~ith the inventioll, the filling chamber and the discharge chamber are
formed in the refractory lining of the vessel.
In accordance with another preferred embodiment, -the channels for com-
municating the filling chamber and the discharge chamber extend at least
nearly horizontally.
In accordance with another preferred embodiment of the apparatus accord-
ing to the invention, the discharge chamber is directly in co~nunication
with a mold stone.
Referring now particularly to the drawings, molten metal is passed from
a smelting furnace, not shown, by means of an inlet conduit 1 to a vessel 2,
either continuously, or in batches.
In the refractory lining 3 of vessel 2 a filling or receiving or supply
chamber 4 and, spaced at a distance therefrom, a discharge chamber 5 are pro-
vided, the cross section of the latter decreasing in the direction of the
mold connection. The supply chamber 4 and the discharge chamber 5 are con-
nected by means of channels 6 (Fig. 2), i.e., the channels extend, approxi-
mately at the height of the horizontal longitudinal axis 7 of a mold, not
shown, through a core 8 which separates the supply chamber 4 and the dis-
charge chamber 5. Viewed in the direction of the mold connection, the supply
chamber 4 is provided ahead of discharge chamber 5. A mold stone 9 extends
into the reduced section 5' of the discharge chamber 5. The pertaining mold,
not shown, can mechanically be placed in contact9 under pressure, against
the outwardly directed flange end face 9' (Fig. 2) of the mold stone 9.
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The channels 6, the longitudinal axis 6' (Fig. 1) of which extends
preferably horizontally, or at least nearly horizontally, are arranged and
formed, when viewed in the plan view according to Fig. 2, such that the low
metal volume passed and accelerated through the channels reachcs directly
the region oE the bore 9" of the mold stone cmd, therefore, directly the
region oE the drawing cross section of the mold, not shown.
The vessel 2, furthermore, is equipped with cm induction heating means
10 which is preferably formed and arranged so that it is particularly effect-
ive in the region of the channels 6, i.e., the metal volume passed there-
through is rapidly heated and simultaneously directed in the direction to-
wards the mold stone 9. The induction heating means 10 is generally com-
prised of a core 11 and a pertaining winding 12. In the preferred embodi-
ment (cf. Fig. 1) the components 11 and 12 extend completely through core 8.
This core 8, accordingly, is provided with a through-bore 13 (Fig. 2).
During the drawing operation, the supply chamber 4 is closed by a plug
14 which is supported in the bore of a tap hole (Abstichloch) 15 associated
with vessel 2. Exemplary, the capacity of the chambers 4 and 5, inclusive
of section 5' and the channels 6 is 200 kg. which corresponds to an overall
length of vessel 2 of about 1 meter.
Since the metal flowing from the supply chamber 4 into the discharge
chamber 5 is heated in the region of the channels 6, an overheated metal
mass reaches the mold stone 9 or the mold~ so that the danger of producing
undesirable solidifications in the vicinity in front of the mold is removed
or at least reduced. With appropriate formation and control of the induc-
tion heating means 10, it can, furthermore, be ensured that the metal volume
in the region of channels 6 has an orientation towards the direction of the
mold stone 9 and the mold, not shown.
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The induction heating is preferably continuously controllable by means
of an induction regulator or adjustable transformer, not shown. The con-
tinuous control of tlle heating can be part:icular:ly cffcc-ted on the bas:is of
cont:i.nuous temperELture mon:itor:ing, for examp.Le, at the f.lange mounting lo-
CELtiOII of the mo.ld, not shown, on the mold stone 9.
~ n impor-tant a.dvEmtage of the :invention resides therein that heating,
and, thereby, overheat:i.ng of the metal that is being worked with, can be
very rapid].y attained, so that the usual attendant inertia of known vessels
is overcome. The heating can, particularly, be carried out within a period
of time of from less than 1 minute to maximally 10 minutes. This short
period is possible because a relatively small metal vo:lume, namely that
respectively present in the chalmels 6, is subjected to a high inductively
produced heat energy of between about 10 to 300 kW. This high energy, ex-
tending in the direction towards the mold, can be controlled so that i.t ex-
ceeds the recooling near the mold at highest conductivity values, so that it
is possible to counteract the solidification conditions in the mold in the
manner required for production of acceptable products.
In a modification of the embodiment, the apparatus, in accordance with
a preferred embodiment, can include a mold stone, not shown, with several
openings, reaching into the discharge chamber 5 or its reduced section 5'.
Furthermore, the single-phase inductor shown in the drawings can be re-
placed by a multi-phase inductor.
The present invention is, of course, in no way restricted to the speci-
fic disclosure of the specification and drawings, but also encompases any
modifications within the scope of the appended claims.
