Note: Descriptions are shown in the official language in which they were submitted.
12/03/98 THTJ 18:14 FA$ 1212 972 5487 COHEN PONTANI ET AL l~ 003
1
Strip Casting Plant F ~ L E, ~ T ti I S
TF'~' ' a'.~f~9SLAT~~~~J
Description
The invention relates to a strip casting plant, especially for the strip
casting of steel.
When strip casting steel, it is largely possible to optimally select the
casting thickness of the
strip (e.g., approximately 10 mm) in keeping with the required thickness of
the knish-rolled
hoc strip (1 to 3 mm) and for the purpose of attaining adequate material
properties in light of
the; reduired heat deformation.
Dl? 31 ~42 099 discloses a device for the continuous casting of metal that has
a supply device
for molten metal, a carrying belt for molten and solidified metal, and side
limits closely
adjacent to the carrying belt. The side limits are attached to the carrying
belt in the manner
of a link chain.
Such a design is quite expensive technically. Moreover, it is basically
suitable only for
re:iatively small strip widths. The stress in the carrier due to the thermal
load is substantially
higher with larger strip widths than with narrow strips; thus, the
aforementioned side limit,
which revolves in a chain-like fashion and acts as a reinforcement, cannot be
used with large
strip widths.
V~i'hen side limits are used that remain stationary relative to the carrier or
conveyance device
of the cast strip, solidified steel occasionally sticks to a side limit during
the casting process.
This leads to massive defects in the strip and to operational disruptions or
even interruptions
in casting. Similar problems can occur in the supply device, since solidified
steel occasionally
sticks there as well, leading to similar difficulties.
CA 02268944 1998-12-04
CA 02268944 2003-09-30
20337-507
2
The object :is therefore to indicate a strip
casting plant that reliably prevents the adhesion of
solidified steel to the supply device or side limits.
This object is attained by embodying the supply
device and/or side limits so that they can vibrate on the
plane of the carrying belt and are connected to a device
that produces vibrations. This measure prevents the
adhesion of solidified material.
Accordingly, in a broad aspect of the invention,
there is provided a strip casting plant, comprising: a
supply device for supplying molten metal; a carrying belt
for carrying a strip of molten and solidified metal, the
supply device being arranged to supply molten metal to the
carrying belt; side limits closely adjacent to the carrying
belt, the side limits being adjustable at an angle to each
other for improving an evenness of a thickness of the strip
on the carrying belt over a width of the strip; and means
for vibrating at least= one of the supply device and the side
limits in a plane of t=he carrying belt, the vibrating means
being operative to vibrate at least one of the supply device
and the side limits substantially perpendicular to an upper
surface of the strip so as to cause relative movement
between the supply device and the side limits in a first
spatial direction, and to vibrate the side limits
simultaneously both perpendicular and parallel to a casting
direction so that the vibration has components in three
spatial directions.
In a second broad aspect, there is provided a
method for preventing adhesion of solidified steel to a
molten steel supply device and side limits adjacent a
carrying belt for molt=en and solidified metal, in a strip
CA 02268944 2003-09-30
20337-507
2a
casting plant, the method comprising vibrating at least one
of the supply device and the side limits in a plane of the
carrying belt substantially perpendicular to a conveyance
direction of a strip produced by the casting plant, and
adjusting the side limits at an angle to each other for
improving an evenness of a thickness of the strip on the
carrying belt over a width of the strip.
In.a preferred embodiment, the vibrations of the
supply device and/or side limits occur substantially
vertically to the conveyance device of the strip. Thus, the
vibrations occur on the plane of the carrying belt or the
cast steel strip, but at a right angle to the conveyance
device. Advantageously, this design is less expensive than
one that vibrates in t~~e conveyance direction, wherein the
side limits would have to run exactly over the entire
length. In addition, this embodiment advantageously allows
the vibrations to be optimally adjusted in the region of the
metallurgical length (from the pouring area to complete
strip solidification). This is done, for example, by
dividing the side limits in this region into individual
sections with optimal frequencies and amplitudes.
In a further preferred embodiment, the side limits
can be set a~ an angle relative to each other. This is true
for side limits located across from each other as well as
for sections located on one particular side. As a result,
the evenness of the strip thickness can be improved over the
entire width of the cast strip. In particular, side limits
are also inclined relative to the vertical toward the
carrying belt surface.
In a preferred example, the side limits comprise
water-cooled hollow profiles.
12/Oa./98 , THU 18:15 FAg 1212 972 5487 COHEN PONTANI ET AL f~ 005
3
Preferably, the devices to produce the vibrations are eccentric drives.
However, electric
magnets or hydraulic cylinders can also be used. The vibrations can be
sinusoidal, sawtoothed
or trapezoidal in form, for example. The stroke frequency is, for example, 50
Hz at a stroke
of ~).5 mm. The cooling water is supplied via flexible hoses. Over the cast
strip, there is
preferably a cover, in which a layer of temperature-stable sealing material,
especially ceramic
fiber felt, is arranged for the purpose of sealing between the side limits and
the cover. A
corresponding seal is also provided between the supply device and the carrying
belt, whereby
an aluminum sheet is preferably inseirted between the carrying belt and the
seal, so that when
vibrations occur, relative movement takes place only between the felt layer
and the aluminum
sheet. The supply device and the side limits acre preferably held by helical
screws.
In a further preferred embodiment, the side limits can simultaneously vibrate
both vertically
and parallel to the strip movement (casting direction), so that all told a
thrust force that also
acts in the casting direction is exerted on. the strip edge. Specifically, the
vibration has
components in all three spatial directions.
Furthermore, the vibrations can occur vertically to the strip surface.
In a special embodiment, the vibrations are generated by impacts in the
longitudinal or
transverse direction of the side limits. Shock-like longitudinal waves, with
which adhesion can
be effectively prevented, can be applied in this way.
CA 02268944 1998-12-04
