Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CASTING DEVICE
DESCRIPTION
Technical Field
The invention relates to a caster for casting, in particular, a liquid steel
on a
horizontal conveyor belt according to preamble of claim I and to a method of
operating a caster according to preamble of claim 8.
State-of-the-Art
In state-of-the art, known are casters in which liquid steel flows from a
casting
ladle in a distribution device and therefrom on a horizontal conveyor belt on
which the liquid metal solidifies to a pre-strip and simultaneously is carried
away and is cooled. This method is also known as a horizontal casting.
Corresponding casters are known in the state-of-the art and are disclosed in
DE
198 52 275 or WO 97/06906.
The casters for a horizontal casting described above have a drawback that
consists in that their width is fixed, and that a substantial modification of
the
installation is required in order to change the cast width of the horizontal
conveyor belt and, thus, of the pre-strip, in case such modification is
economically justified at all. To this end, typically a very extensive
assembly
and disassembly is necessary, and expensive components are needed, so that
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such change of an installation in width in any event, has little appeal.
Correspondingly, for different cast widths, different horizontal casting
installations are produced which then, on close examination, can be used to
their full capacity.
This drawback results in that a change in an installation is relatively
expensive
and idle time is increased, or requires producing a second, third, or several
installations, with an increased costs factor.
All in all, these solutions up to now are associated with increased costs and
loss of time, which leads to an inflexible operation or to production losses
of
such casting installations.
DESCRIPTION OF THE INVENTION, OBJECT, SOLUTION,
ADVANTAGES
It is an object of the present invention to provide a casting installation for
casting, in particular, steel onto a horizontal conveyor belt, with which
difficult
requirements with regard to dimensions of to-be-cast pre-strips can be
realized
quickly and without large expenses.
According to the invention, this object is achieved, with respect to a caster,
by
providing a caster having a casting ladle, a distribution device and a
horizontally displaceable conveyor belt having side limitation elements, in
which liquid metal, preferably, steel flows from the casting ladle in the
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distribution and therefrom onto the horizontal conveyor belt, wherein the side
limitation elements of the horizontal conveyor belt are adjustable over the
width of the horizontal conveyor belt. Thereby, it can be advantageously
achieved that the pre-strip, relevant for the casting process, can be formed
variable in width. The adjustment can be effected advantageously
mechanically or hydraulically with a corresponding servo element.
Advantageously, the adjustment is reversible.
Advantageously, the distribution device is adjustable in width in direction of
the
width of the conveyor belt. Thereby, advantageously, the casting behavior and
distribution behavior of the liquid metal on the conveyor belt can be
controlled. It is further expedient, when beneath the horizontal, conveyor
belt
stand/or above the horizontal conveyor belt, at least one tempering, e.g.,
cooling device is arranged and which serves for cooling a pre-strip
displaceable
with speed on the conveyor belt.
It is particularly advantageous when the at least one cooling device is
variably
adjustable in width in direction of the width of the conveyor belt.
It is further advantageous when the at least one cooling device is divided in
width in cooling zones in direction of the width of the conveyor belt.
It is particularly advantageous when the cooling device has a plurality of
cooling zones, of which at least two zones are edge zones which are turned on
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or off dependent on a to-be-cooled width.
According to the invention, the object of the invention, with respect to a
method, is achieved with a method of operating a caster, in particular a
caster
having a distribution device and, in particular, a horizontally displaceable
belt
with side limitation elements, wherein a width of a cast product is determined
and adjusted with side limitation elements adjustable in width at an angle of
90 to a cast direction.
This is particularly advantageous when the distribution device is arranged
between the side limitation elements.
With another embodiment, it is also advantageous when the distribution
device is located, in the cast direction upstream of the side limitation
elements
and the liquid metal flows head-first against the side limitation elements and
narrows to a casting width by the side limitation elements.
Further advantages are disclosed in subclaims.
Brief Description of the Drawings
Below, the invention will be explained based on an embodiment shown in the
drawings.
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The drawings show:
Fig. 1 a cross-sectional schematic view of a caster;
Fig. 2 a plan schematic view of a cooling device with an adapted
or adjustable width;
Fig. 3 a plan schematic view of a cooling device with an adapted
or adjustable width;
Fig. 4 a plan schematic view of a cooling device with an adapted
or adjustable width;
Fig. 5 a plan schematic view of a cooling device with an adapted
or adjustable width;
Fig. 6 a plan schematic view of a cooling device with an adapted
or adjustable width; and
Fig. 7 a plan schematic view of a cooling device with an adapted
or adjustable width.
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PREFERRED EMBODIMENT OF THE INVENTION
Fig. 1 shows a schematic cross-sectional view of a caster 1 in which the
liquid
steel or a liquid metal is poured from a casting ladle 2 into a tundish 3 and
runs
therefrom via a distribution device 4 onto a horizontal conveyor belt 5. The
horizontal conveyor belt 5 is a driven belt that conveys further the metal
solidified on the conveyor belt, such as a pre-strip 7, with a predetermined
speed. To this end, there are provided rollers 6 about which the driven belt 5
circulate as a continuous belt.
Preferably, beneath the conveyor belt 5 andlor also above the conveyor belt 5
there are provided cooling devices 9 which serve for controlled and precise
cooling of a cooled and solidified pre-strip 7 displaceable on the conveyor
belt 5 with a certain speed. The cooling devices 9 are formed as, e.g., spray
devices for spraying a cooling medium such as, e.g., water that is sprayed
on or is applied to the conveyor belt and/or the pre-strip. The cooling device
9
can, e.g., can cool the heat-transmitting belt 5 itself, so that a solidified
metal
deposited on the conveyor belt 5 is cooled. Thereby, the heat of the pre-strip
7
is removed from the pre-strip by the sprayed or applied cooling medium.
Above the conveyor belt 5, there is provided an inert gas hood 8 that protects
the pre-strip from the external atmospheric air. The inert gas hood 8 can also
be
positively supported on side limiting elements 13, 14 to prevent loss of heat.
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The side limiting elements are shown only schematically.
Figs. 2 through 7 show schematically a plan view of a caster 10 and in which
essentially only the cooling device 11 located above and/or below the
horizontally displaceable conveyor belt, the distribution device 12, and two
side
limiting elements 13, 14 are shown. The conveyor belt and the side limiting
elements are shown only schematically.
In Fig. 2, it can be seen that the two side limiting elements 13 and 14 are
located relatively closer to each other in comparison with the arrangement in
Fig. 3. The distribution device 12 has, at its outlet, a width that
corresponds
approximately to the distance between the two side limitation elements. Thus,
Fig. 2 shows an arrangement for a small strip width and in which the width of
the outlet of the distribution device 12 approximately corresponds to the
widtls
of the conveyor belt.
Contrary to this, in the caster of Fig. 3, the width is adjusted to a greater
width
so that the width of the produced pre-strip, i.e., the distance between the
side
limitation elements 13, 14 is greater than the width of the distribution
device
12 of the liquid metal at its outlet. The width of the distribution device 12
at its
outlet is not changed in Figs. 2 and 3.
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In Fig. 4, both side limitation elements again are arranged relatively closer
to
each other in comparison with the arrangement of Fig. 5. The distribution
device 12 has a width greater than the distance between the both side
limitation
element 13, 14. The caster in Fig. 4 shows an arrangement for a small strip
width.
Contrary to the arrangement in Fig. 4, the caster in Fig. 5 is adjustable to a
greater width so that the width of reproduced pre-strip, i.e., the distance
between the side limitation elements 13, 14 is as wide or smaller than the
width of the distribution device 12 of the liquid metal at its outlet. The
width of
the distribution device 12 at its outlet is not changed in Figs. 13 and 14.
The
width of the distribution device 12 can, alternatively, be changeable in
another
embodiment.
All in all, Fig. 2-5 show, respectively, a caster 10 with side limitation
elements
13, 14 with an adjustable distance therebetween. The distribution device 12
for
distributing the liquid metal on the conveyor belt of the caster can be formed
with an outlet having an adjustable width. The width of the pre-strip
between the side limitation elements 13, 14 can be smaller, equal to, or wider
than the width of the distribution device 12 at its outlet. By adjustment of
the
width of the distribution device 12, streams with different mass can be
brought
onto the conveyor belt of the caster in which, the width of the distribution
device
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12 with respect to the stream mass can be adjusted, taking into account the
width of the pre-strip.
If the distance between the side limitation elements 13, 14 is greater than
the
width of the distribution device 12 at its outlet, the distributed liquid
metal also
flows in the width direction on the conveyor belt, being distributed to the
strip
width of the pre-strip determined by the distance between the side limitation
elements 13, 14.
If the distance between the side limitation elements 13, 14 is smaller than
the
width of the distribution device 12, the exiting liquid metal that flows in
the
width direction strikes against the side limitation elements 13, 14 on the
conveyor belt and spreads over the entire strip width determined by the width
of the side limitation elements 13, 14. If the distance between the side
limitation elements 13, 14 is essentially equal to the width of the
distribution
deice 12, the exiting fluid metal flows essentially parallel to the belt width
on
the conveyor belt and spreads over the entire belt width determined by the
width of the side limitation elements.
In addition to the adjustment of the width of the side limitation elements 13,
14 of the conveyor belt and/or the distribution device 12, the cooling device
11
can also be adjustable to a variable width, so that the cooling device 11 can
be adjusted to a variable width with regard to its cooling capacity or cooling
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temperature. The cooling device 11 can be divided in different cooling zones
over the width of the belt of the caster so that, e.g., edge cooling zones 15
at the
edges of the cooling device 11 can be turned on or off in case they are needed
or not, based on a selected width of a to-be-cast pre-strip. Fig. 6 and 7 show
such an embodiment in which the cooling device 11 is adjusted to different
active widths. In Fig. 6, the edge zones 15 are, respectively, turned off, and
in
Fig. 7, the edge zones of the cooling device 11 are activated, i.e., they are
used
for cooling the pre-strip. Activation and deactivation of the edge cooling
zones 15 is effected, preferably, dependent on the adjusted width of the pre-
strip,
i.e., dependent on the distance between the side limitation elements 13, 14.
According to the invention, it is particular advantageous when the adjustment
of the width of a to-be-east material can be reversibly carried out. To this
end,
the adjustment of the distance between the side limitation elements 13, 14
is reversibly carried out. Advantageously, in one of the embodiments, the
cooling with the cooling device with cooling zones is also adjustable to the
necessary width. In addition, it is advantageous when the adjustment of the
width of the distribution device 12 is reversibly carried out. According to a
particular advantageous embodiment, all three, the width of spacing of the
side
limitation elements 13, 14, the width of the distribution device 12, and the
width of the coding device 12, 15 are reversibly adjustable. It is
particularly
advantageous that this reversible adjustment can be effected and changed
during operation, i.e., on line.
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List of Reference Numerals
1 Caster
2 Casting ladle
3 Tundish
4 Distribution device
Conveyor belt
6 Roller
7 Pre-strip
8 Inert gas hood
9 Cooling device
Caster
11 Cooling device
12 Distribution device
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13 Side limitation element
14 Side limitation element
15 Cooling zone, edge zone
12
