Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02711833 2010-01-26
COMPACT, FLEXIBLE CSP FACILITY FOR CONTINUOUS,
SEMI-CONTINUOUS AND BATCH OPERATION
DESCRIPTION
TECHNICAL FIELD
The invention relates to a compact, flexible CSP installation for endless,
semi-
endless and batch operation, as in particular in accordance with the
introductory
clause of Claim 1.
PRIOR ART
In CSP installations (Continuous Strip Production), the strip is typically
produced in a continuous process, as the name already suggests. This means
that the casting process and the rolling process take place directly in
succession from almost one heat.
The DE 10 2006 054 932 Al discloses a CSP installation in which both an
induction furnace and a holding furnace are provided between the casting
machine and the rolling train, in order to keep the thin slab to temperature
or to
increase the temperature slightly, in which both the holding furnace and also
the
induction furnace are activated, deactivated or respectively controlled or
regulated depending on the type of operation.
EP 0 286 862 Al discloses an endless rolling, in which the casting and the
rolling processes are directly coupled.
DD 282 185 A5 discloses a discontinuous process, in which the casting takes
place in a casting house, in which at the end of casting, after running
through a
roughing stand, coils of starting material are produced. These coils are then
transported into the hall of the rolling process, in order to be rolled there.
These installations have the disadvantage that they can either be operated in
discontinuous operation or only in continuous operation. With a changeover of
rolls, in the case of a continuous operation it is no longer possible to
maintain
the operation. In the case of a discontinuous operation, for many types of
steel
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it is unfavourable to manufacture them in such a way, because losses in
quality are
connected therewith.
In addition, these installations are generally very long in their extent,
which leads to
a considerable cost factor in manufacture.
DESCRIPTION OF THE INVENTION, OBJECT, SOLUTION, ADVANTAGES
It is an object of the present invention to provide an installation of the
above-
mentioned type, which allows a flexible change of type of operation and is
nevertheless relatively short in construction.
According to the invention, the object is achieved by a compact, flexible CSP
installation for endless, semi-endless and batch operation with a casting
machine, a roughing stand group and a finishing stand group, in which for
batch operation
or semi-endless operation a coil store is integrated into the roll table,
which stores the
pre-strip or slab coming from the roughing stand, with the coil store being
deactivated
in the case of endless operation. Thereby, a flexible utilization of the
installation can
be realized with, at the same time, a short type of construction.
In another aspect, the present invention resides in a compact, flexible
Continuous Strip
Production (CSP) installation for endless, semi-endless and batch operation
comprising:
a roll table; a casting machine coupled to the roll table; a roughing stand
group coupled
to the roll table; and a finishing stand group coupled to the roll table;
characterized in
that when in batch operation or semi-endless operation, a coil store is
integrated into the
roll table for storing a pre-strip or a slab coming from the roughing stand
group, and
when in endless operation, the coil store is deactivated.
It is, in addition, expedient here when a furnace, such as for example a
tunnel furnace,
which also serves as a store, is arranged before the roughing stand group.
It is also advantageous if a heating arrangement, such as an induction heating
arrangement for example, is arranged between the roughing stand group and the
finishing stand group.
It is, in addition, expedient, if the coil store is designed for an increased
holding amount
of pre-strip or slab.
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Furthermore, it is advantageous if the coil store is designed to receive two,
three or
more coils. In this respect, the coil store has an increased holding capacity
with a
short length of the installation.
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It is, in addition, expedient if the coil store is thermally insulated and/or
is
heatable.
In addition, it is advantageous if in the case of a deactivated coil store, a
roll
table covering is used for better thermal insulation of the roll table.
Thermal
losses can thereby be minimized and the energy which is to be expended for
tempering can be reduced.
Advantageous further developments are described in the sub-claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in further detail below on the basis of example
embodiments with the aid of the drawings, in which:
Fig. 1 shows a diagrammatic illustration of an installation according to the
invention,
Fig. 2 shows a diagrammatic illustration of an installation according to the
invention in side view,
Fig. 3 shows a diagrammatic illustration of an installation according to the
invention of Figure 2 in top view,
Fig. 4 shows a diagrammatic illustration of the installation according to the
invention in side view for the continuous operating mode,
Fig. 5 shows a diagrammatic illustration of the installation according to the
invention according to Figure 4 in side view for the discontinuous operation
or
the semi-endless operation,
Fig. 6 shows a diagrammatic illustration of an installation according to the
invention in side view for the continuous operation mode,
Fig. 7 shows a diagrammatic illustration of the installation according to the
invention according to Figure 6 in side view for the discontinuous operation
or
the semi-endless operation,
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Fig. 8 shows a diagrammatic illustration of an installation according to the
invention in side view for the continuous operation mode,
Fig. 9 shows a diagrammatic illustration of the installation according to the
invention according to Figure 8 in side view for the discontinuous operation
or
the semi-endless operation,
Fig. 10 shows a so-called coil store with increased holding capacity in side
view,
and
Fig. 11 shows a view of the coil store according to Fig. 10 from above.
PREFERRED EMBODIMENT OF THE INVENTION
Figure 1 shows a diagrammatic illustration of a compact, flexible CSP
installation 1 for endless, semi-endless and batch operation. The installation
1
has here a casting machine 2 with a caster outlet 3. After the caster outlet
3, a
cutter 4 is provided, in order to be able to cut the strand 5 emerging out
from the
caster outlet 3. After the cutter 4, a furnace 6 is provided, such as
preferably a
tunnel furnace, which heats the strand 5 up to the desired temperature. The
furnace 6 is therefore arranged between the caster outlet 3 and the cutter 4
on
the one hand and the subsequent roughing stand group 7 on the other hand. In
the example embodiment of Figure 1, the roughing stand group 7 has two
roughing stands. However, according to another idea in accordance with the
invention, the roughing stand group 7 may also have one or three roughing
stands. In this example embodiment, after the roughing stand group 7 a so-
called coil store 8 is provided for the strand material, in order to wind the
strand
material for the batch operation into coils and to store them intermediately.
The
coil store 8 is designed in such a way that it can for example hold and store
intermediately so much strand material that, for example, a changeover of roll
is
possible in one or more finishing stands of the finishing stand group, without
the
casting machine 2 having to be restricted or shut down.
After the roughing stand group 7 and the coil store 8, advantageously a
straightening roller set 9 is provided. Thereafter, a cutter 10 can again be
arranged. After the cutter 10, optionally an edge heater 11 is provided, after
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which an induction furnace 13 is arranged. After the induction furnace 13, the
finishing stand group 12, which is also known as the finishing train, is
provided,
which in the example embodiment of Figure 1 has six finishing stands.
According to a further idea in accordance with the invention, it is also
advantageous if with the arrangement of three roughing stands of the roughing
stand group, the finishing stand group 12 has five finishing stands, for
example.
In batch operation, the casting machine 2 no longer operates inline or
continuously with the roughing stand group 7 and the finishing stand group 12.
This brings about a rolling in both stand groups 7, 12 with increased rolling
speed, which leads to smaller temperature losses on the pre-strip and the
finished strip, which leads to advantages, because thereby in the inductive
heating arrangement 13, less energy has to be introduced.
A cooling section 14 and a further cutter 15, and also the winding spool 16
are
arranged after the finishing stand group 12.
It is advantageous in the arrangement of the furnace 6 before the roughing
stand group 7, that depending on the length of the tunnel furnace 6, the
latter
can serve as a buffer or as a holding furnace.
Figure 2 shows a diagrammatic view of a CSP installation 101 according to the
invention in a side view, with Figure 3 showing the CSP installation 101 in a
view from above.
Through the use of an installation 101 according to Figures 2 or 3, a coupled,
fully continuous casting/rolling process, so-called endless rolling, or
optionally
an uncoupled, discontinuous processing of individual slabs in the so-called
batch operation is possible. The installation 101 is constructed here in a
very
space-saving manner, so that only approximately half an installation length is
required compared with a conventional CSP installation. The installation 101
nevertheless allows a change of working roll in the roughing stand group
and/or
in the finishing stand group without, in so doing, having to interrupt the
casting
process.
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The installation 101 preferably has the following components, with individual
items of these components also being able to be arranged at a distance and/or
elsewhere in the flow of material.
At the inlet side, the installation 101 has a casting installation 102 which
can
preferably also be equipped with a strand cooling device 103, which can be
provided with a possibly close cooling zone division for a temperature zone
regulation over the width, in order to be able to set a homogeneous outlet
temperature from the casting- or continuous casting installation 102.
Arranged after the casting installation 102, a scale washer 104 and/or a slab
cleaning device 104 is provided, which can clean the emerging slab
accordingly. A slab cutter 105 is provided, arranged after this. The slab
cutter
105 can be used to separate off the cold strand at the sprue, to separate the
slabs for example in individual slabs, to separate after every nth slab with,
e.g.
n=2, 3 or greater for semi-endless rolling operation and/or for chopping the
slab
in the case of any disturbances which may be present.
Subsequently in the flow of material, a cold strand removal device 106 is
provided. Here, for example, the cold strand can be taken at the sprue out of
the transportation line of the installation 101 via a bracket or by means of a
chain upwards or to the side via a displacement unit.
In addition, in the flow of material a roll table covering 107 is provided,
which
can be swung down to reduce the temperature loss of the slab. When the
coverings 107 are swung upwards, cut slab plates can also be carried out in
this
working area in the case of longer disturbances.
In addition, heated ferries and/or furnace parts 108 are provided, which can
be
arranged one behind the other, for example. The heated ferries 108 and/or
furnace parts can also serve as additional slab stores for the time or the
mode
of operation in which for example a change of rolls is carried out in the
roughing
stand group 111 and/or in the finishing stand group 118, in which slabs or
divided slabs 109 can be taken out from the main transportation line.
Alternatively, instead of a ferry, a furnace, such as for example a lifting
beam
furnace, can be used alongside the main transportation line. On transportation
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through the ferry and/or the furnace, preferably the slab temperature is
substantially maintained here or is only slightly reduced.
At low casting speeds, a slab heating can also be provided here and carried
out
in order to be able to set flexibly almost constant inlet temperatures for the
subsequent rolling process. The two ferries 108, arranged one behind the
other,
have individually or in total preferably the length of a slab 109 with a
maximum
coil weight plus a tolerance, so that some play can be kept for swinging the
slab. The ferry- or furnace region 108 is therefore constructed so as to be
relatively short in its structural length.
Arranged after these elements, if applicable scale washers 110 are again
arranged before the roughing stand group 111, also known as roughing train,
roughing rolling train or roughing stand train. The roughing stand group 111
preferably consists of one to four roughing stands 112, preferably 2 or 3
roughing stands. In the roughing stand group 111, the slab is rolled down from
for example 70 to 110 mm to approximately 15 to 50 mm. In the so-called
discontinuous operation, also known as batch operation, the roughing stand
group rolling speed, i.e. the rolling speed in the roughing stand group 111,
can
be set independently of the casting speed of the casting installation 102. The
choice of the roughing stand group rolling speed takes place advantageously so
that the maximum furnace transportation speed of for example 1 m/s and the
maximum winding speed in the coil store of for example 3 m/s can be
maintained.
In order to realize such different speeds, a speed coordination takes place
between the roughing stand group 111 and the so-called coil store 113, also
known as the coilbox. The coil store 113 constitutes here a device for the
winding or collecting of strand material and for if applicable chronologically
staggered unwinding or guiding out of strand material.
To balance out mass flow differences between the roughing stand group 111
and the coil store 113, a so-called looper or a sagging strip region with a
strip
loop regulating arrangement can be provided there. This can be important in
particular for thinner pre-strips.
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For the further development of the installation, a leveller and an induction
heating arrangement (not illustrated) can be arranged behind the roughing
stand group 111 and before the coilbox 113. This arrangement can preferably
be activated in the endless mode.
As can be seen in Figure 2, a roll table covering 114 can be provided in the
region of the coil store 113. Instead of the coil store 113, a roll table
covering
114 can be provided for the pre-strip, whereby the pre-strip is thermally
insulated, so that the expenditure of energy is reduced, in order to keep the
pre-
strip at the desired temperature. This is particularly advantageous in the
endless mode, i.e. rolling at casting speed.
The roll table covering 114 can be provided alternatively to the coil store
113 or
can if applicable also cover the coil store 113 itself. If the coil store 113
is not
required for the continuous operation of the installation 101, then the
winding
and unwinding mechanisms of the coil store 113 can be deactivated or swung
out, so that the pre-strip can pass the region of the coil store 113. In this
case, a
lowering of the roll table covering 114 would therefore bring about an
improved
insulation of the roll table for the pre-strip.
The coil store 113 is expediently designed for holding normal individual coils
and/or so-called jumbo coils. Individual coils here are coils, i.e. windings
of
individual pre-strips or individual slabs. So-called jumbo coils are windings
of
several pre-strips or of several slabs. The jumbo coils are therefore
typically
windings of two or three or more pre-strips or slabs. For the case where the
coil
store 113 has a holding capacity of jumbo coils, accordingly several pre-
strips
or slabs can be wound and stored and unwound again and delivered to the
further process.
By the winding of the pre-strips or slabs, space is saved in particular in
length,
which therefore reduces the length of the installation with, at the same time,
a
very large store.
In continuous operation of the installation or in endless mode, or with non-
use of
the coil store 113, as stated above, the length region of the coil store is
covered
by a roll table covering 114 in order to reduce pre-strip temperature losses.
Instead of the coil store 113 with passive thermal insulation laterally and
from
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above, alternatively also a heated coil store can be arranged directly behind
the
roughing stands or alternatively one or two coil furnaces.
After the coil store 113, an arrangement of straightening rollers 115 is
provided.
These are intended to produce a straight, undulation-free pre-strip form, in
order
to be able if applicable to transport the pre-strip reliably through the
following
induction heating arrangement.
The cutter 116 provided after the straightening rollers 115 serves for
conditioning the strip end form at the head and/or at the end after the coil
store
113 and/or before the induction heating arrangement 117 or eliminates non-
straight pre-strip end forms, such as a ski shape for example.
With the subsequent induction heating arrangement 117, the pre-strip can be
brought individually to the desired finishing stand group inlet temperature.
Thereby, higher temperatures can be set, such as for example 1350 C in the
rolling of grain-oriented silicon steel (GO Si steel) or with other materials.
Higher
temperatures can also be set with thin strip rolling with a thickness of H<1.5
mm. The temperature can also be increased when the pre-strip temperature is
too low. Low temperatures can also be produced, without or with only a small
energy input, so that in the case of normal strips energy can be saved.
Furthermore, homogeneous temperatures can therefore be produced over the
pre-strip length, in order to thereby balance out any temperature
irregularities at
the head and end, which may possibly have occurred in the coil store 113,
through different energy introduction over the pre-strip length.
In the case where the installation 101 is operated in an endless mode with a
relatively low casting speed and hence a low rolling speed in the roughing-
and
finishing stand group 111, 118, the induction heating arrangement 117 serves
for setting a desired rolling temperature.
This induction heating arrangement 117 can be assisted before the finishing
stand group optionally also by further induction heating arrangements within
the
finishing stand group 118 itself. The induction heating arrangement 117 before
the finishing stand group 118 is advantageously constructed so as to be
transversely displaceable or able to be swung up, so that the induction
heating
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arrangement can be replaced by a passively insulating or even heated roll
table
covering as required.
In the material flow after the heating arrangement 117, cleaning devices 119,
such as scale washers for example, are provided, which are arranged before
the finishing stand group 118.
In the following finishing stand group 118, also known as the finishing train,
advantageously 3 to 7 finishing stands 120, for example 5 finishing stands
120,
are provided. In the finishing stand group 118, the pre-strip is rolled down
to an
end thickness of approximately 0.8 - 16 mm.
Between the stands 120 of the finishing stand group 118, in addition heating
arrangements 121 can be provided, in order to heat up the strip material.
After the finishing stand group 118, a cooling section 122 is provided, in
order to
cool down the rolled strip 123, before it can be cut by the strip cutter 124,
such
as for example the thin strip cutter, and is then wound on spools of a spool
installation 125. The thin strip cutter is used here for cutting the strips
123
shortly before the spool, when the installation 101 is operated in the endless
or
semi-endless mode.
For the installation 101 of Figures 2 and 3 there are now various modes of
operation in which the installation 101 can be operated.
The so-called batch operation, also known as discontinuous operation of the
installation, has a discontinuous operation in the roughing- and finishing
stand
group 111, 118. At the beginning of a casting process, on the putting into
operation of an installation 101, with general casting problems or with steels
which are difficult to cast, the casting speed is set relatively low. At low
casting
speeds, an endless rolling with this low mass flow from the casting
installation
102 up to the finishing train 118 is not efficient for temperature reasons, or
uneconomical. To reduce the energy losses, the batch operation is therefore
preferably used. In the batch process, the casting process, the rolling in the
roughing train 111 and the finish rolling in the finishing train 118 are
partially at
least uncoupled and therefore take place at a different speed or with a
different
mass flow.
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After the sprue, firstly the cold strand is removed and the thin slab is
cropped in
the slab head region. After reaching the desired coil weight, the repeated
cropping takes place for each slab at the cutter 105 behind the continuous
casting installation 102. In the roughing train 111, the rolling to pre-strip
thickness then takes place, and thereafter the winding of the pre-strip in a
coil
store 113. After the unwinding and the re-heating of the pre-strip, the
rolling
follows in the finishing train 118 at a likewise individually adjustable
rolling
speed, and the further transportation through cooling section 122 and finally
the
winding in the spool installation 125.
The so-called endless operation is a further mode of operation, in which the
casting machine 102 and the roughing stand group 111 and the finishing stand
group 118 are coupled. With an increasing casting speed, and depending on
the end thicknesses of the band which are to be rolled, a switchover takes
place
into the endless operation. An advantageous range for endless rolling lies for
example in a casting thickness of 80mm and a casting speed of 7m/mm or,
expressed generally, the endless operation is advantageous with a mass flow in
the order of casting thickness * casting speed >_ 550 mm * m/min. With this
endless operation mode, the cutter 124 is used before the spool 125 for
separating the strips. The pre-strip is moved straight through the regions in
which otherwise the pre-strips would be wound in the coil store 113. In order
to
minimize the temperature loss of the pre-strip, roll stand coverings 114 are
swung in in this region. The set of straightening rollers 115 can also be
constructed advantageously if applicable so as to be transversely displaceable
or it can be advantageously moved up with a large space, in order to also be
able to house a thermal insulation here between the roll table rollers and/or
over
the roll table. Before the pre-strip runs into the finishing stand group 118,
it is
heated inductively so that a sufficiently high rolling temperature occurs and
so
that the rolling takes place in the austenitic range. In the subsequent
endless
finish rolling, if applicable optionally also the inductive heating
arrangements
121 are used inside the finishing stand group 118, which assist the inductive
heating arrangement 117 before the finishing stand group 118.
In the discontinuous operation or starting process at the strip head, the
thermal
insulations, on the other hand, are in a waiting position at a distance over
or
adjacent to the strip.
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Furthermore, a so-called semi-endless operation can be realized in the
finishing
stand group 118. The coil store 113 with increased capacity, already mentioned
above, also named the jumbo coilbox, offers the possibility to store two or
more
pre-strips. If, for example, a change of rolls is only to be carried out in
the
finishing stand group 118 or a longer interruption occurs in the finishing
stand
group 118, then in addition to the storage in the furnace before the roughing
stand group 111, the jumbo coilbox 113 can also serve as a store. This means
that the casting installation 102 and the roughing train 111 continue to
operate
in a semi-endless mode, in which they are coupled, and a rolling takes place
in
the roughing stand group 111 and a subsequent winding takes place in the
jumbo coilbox 113 at casting speed.
When the finishing stand group 118 is ready to operate again, then the semi-
endless rolling takes place in the finishing stand group 118 of the two or
more
strips, which were stored intermediately in the jumbo coil store 113. The
separation of the strips is completed at the cutter 124 before the spool 125.
In
the semi-endless mode, the rolling can be operated in the finishing stand
group
118 advantageously at increased speed and with minimized inductive energy
supply and/or with an insert of an intermediate stand cooling arrangement.
A coupled operation mode of casting installation 102 and roughing train 111
are
advantageously set with higher mass flow expressed in casting thickness *
casting speed >_ 350 mm * m/min. A calculation model with a control unit
advantageously monitors that the rolling in the roughing stand group 111 and
the subsequent winding and unwinding in the coil store 113 for centre and/or
edge do not take place below a threshold temperature, such as for instance a
transformation temperature of a steel - i.e. in the austenitic range. If the
furnace
108 is to be constructed longer before the roughing stand group 111, for
example to store two slabs or several slabs one behind the other, then a
rolling
in the roughing stand group 111 is possible at a higher speed independently of
the casting machine 102 and is expedient with regard to energy, and in this
constellation a semi-endless rolling is then also possible in the finishing
stand
group 118.
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According to the invention, a roller change can be carried out in the roughing
stand group 111 and/or in the finishing stand group 118 with an active casting
process.
On changing the working rollers or in the case of interruptions in one of the
rolling trains, the casting process is preferably not to be interrupted or
disturbed
too greatly. Therefore, it is advantageous to install a buffer for the slabs.
For
this, a short roller hearth-type furnace 108 is provided behind the casting
installation 102 in a CSP installation according to the invention, in which,
due to
the method, four half slabs find a place. The furnace 108 is constructed in
its
development in the form of a particular type of ferry, as is illustrated in
Figure 3.
Here, two ferry groups 108a are arranged one behind the other in the
transportation direction, both of which can be moved transversely
independently
of each other. Alternatively, the front ferry group 108a is also installed
fixedly as
a furnace part behind the casting installation 102. In these two ferry groups,
in
total the four half thin slabs find a place. The fields drawn with the broken
line
are withdrawal parking positions for the ferries 108a. A transportation of
slabs
from ferry 108a to ferry 108a alongside the rolling line is also possible, so
that
individually from one or other ferry a transporting back of slabs into the
rolling
line can be carried out. This arrangement facilitates the flexible
transportation
back of slabs after an interruption to rolling, for example in the case of a
roll
change or a disturbance.
As a further alternative development, more than 2 ferry parts or lifting beam
furnace paces adjacent to each other are also conceivable as the second ferry
group 108a, in order to increase the storage capacity with the same overall
length of the installation. If the ferries 108a, like furnaces, are full,
because for
example the interruption of rolling lasts longer, then the following modes of
operation can be provided.
In the case of an interruption of rolling in the roughing stand group 111, a
cutting and discharging of slabs can be carried out before the furnace 108 in
the
region of the cold strand discharge device 106.
Interruptions of rolling in the finishing stand group 111 are generally
necessary
more often. In this case, in this time the pre-strips are rolled out to
desired pre-
strip thicknesses and are wound in the coil store 113. These coils are then
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carried out from the rolling line and sold directly or stored intermediately
in a coil
furnace adjacent to the rolling line, and are later inserted into the process
again.
In the time of roll change in the finishing stand 120, optionally the casting
speed
is reduced, in order to increase the buffer time.
During the rolling of the strip, a setting of specific pre-strip temperatures
by
cooling or by heating is helpful.
Through the choice of the rolling speed in the roughing stand group 111 and
cooling inside or behind the roughing stand group 111, the pre-strip
temperatures can be influenced in a wide range. This can be of interest for
particular materials or tube qualities. Alternatively or in addition, a
cooling
arrangement can also be provided before the finishing stand group 118.
Another possibility for cooling also exists by swinging out or moving out the
induction heating arrangement 117 and the swinging in there of a pre-strip
cooler. The heating takes place by the use of a, for example, inductive
heating
arrangement before the finishing stand group 118.
Figures 4 to 9 show CSP installations 201, 301 and 401 for use in a coupled,
fully continuous casting/rolling process, the so-called endless rolling, and
optionally in an uncoupled discontinuous use of individual pre-strips in batch
operation. In addition, a semi-endless operation is also able to be practised
in
the finishing train. Here, Figures 4, 6 and 8 show the installation for
continuous
operation and Figures 5, 7 and 9 show the respective installation for batch
operation or for semi-endless operation.
The installations 201, 301 or respectively 401 are constructed in a space-
saving
manner, in which advantageous developments fully achieve half the installation
length compared with a conventional CSP installation. The structure of the
installations nevertheless allows a change of working rolls in the finishing
stand
group without interrupting the casting process.
The installation 201 has a 3-stand roughing stand group 211 and a 5-stand
finishing stand group 218. After the casting installation 202, a scale washer
204
is provided, then the roughing stand group 211 and thereafter a cutter 205.
After
the cutter 205, exclusion and removal from the strand can take place. The
removal device 206 is provided for this. For better thermal insulation, the
region
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of the removal device 206 can be provided with a roll table covering 207 in
the
case of non-active removal. Thereafter, a furnace 208, preferably an induction
furnace, is provided, which can heat up or temper the strip material before
the
coil store 213. If the coil store 213 is not required, as in continuous
operation,
then a roll table covering 207 can be used. After the coil store 213, a
straightening roller device 215 is provided which, however, can also be
removed for the continuous operation. Then a cutter 216 is provided in the
flow
of material. After the strip cutter 216, optionally an edge heating
arrangement
217a and an induction furnace 217 are arranged, in order to be able to heat up
the strip before the finishing stand group 218. In addition, scale washers 219
are provided. The finishing stand group 218 advantageously has five finishing
stands F1 to F5. After the finishing stand group 218, a cooling section 222, a
cutter 224 and the spool arrangement 225 are provided.
In endless operation, a roll table covering is therefore provided instead of
the
coil store 213. In discontinuous operation, the coil store is operated and
filled
with strip, which is then delivered to the treatment process again.
Alternatively, a 2-stand roughing stand group and a 6-stand finishing stand
group are also provided, see Figures 6 to 9. Figures 6 and 7 show the roughing
stand group 311 with two stands and the finishing stand group 318 with six
stands. Otherwise, the installation according to Figures 6 and 7 does not
differ
substantially from the installation of Figures 4 and 5. Compared with the
installations 201 and 301 of Figures 4 to 7, the installation 401 of Figures 8
and
9 has no heating arrangement between the cutters S1 and S2. Thereby, the
installation of Figures 8 and 9 is considerably shorter in size than the other
two
installations.
After the casting, for example in a thin slab casting installation with
casting
thicknesses in the range of approximately 60 - 100 mm, the thin slab is rolled
down in a continuous process to a pre-strip thickness of approximately 15 - 60
mm on a 1-3-stand roughing stand group. Subsequently, an inductive heating of
the pre-strip takes place, and the finish-rolling in the 3-7-stand finishing
stand
group to an end thickness of approximately 0.8 - 16 mm. Behind the finishing
stand group, the strip is cooled and wound. The three different operating
states
which have also been described above are provided again.
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It is particularly advantageous for the development according to the invention
when an increase of the winding capacity of the pre-strips in the coil store
is
provided. The coil store is not only used for winding a pre-strip, but in the
case
of a roll change, the production of so-called jumbo coils takes place, in
which
two or more pre-strips are wound to form a pre-strip coil. Hereby, a
sufficient
buffer is created for a roll change. At the same time, the structural space is
substantially less compared with the conventional holding furnace. The storage
of the pre-strips is very compact, which also has the effect of a low
temperature
loss. The crane capacity is configured to n*coil weight.
In Figures 10 and 11, details are illustrated in views of the so-called jumbo
coil
store. In this example, a so-called jumbo pre-strip coil, increased in size
and
expanded in capacity, is produced. This consists advantageously of two or more
pre-strips, in which in the figures an example embodiment is shown with two
pre-strips.
If, for example, rolling is carried out in the endless mode, then the
separation of
the last pre-strip takes place before the roll change by cutter S1. The
remainder
of the strip is finish-rolled and the working roll change is started
thereafter.
During the roll change, the storage of the pre-strips in the jumbo coil store
takes
place as already described. After the winding and transportation of the coil
during the winding process from the winding to the unwinding station, for
example two pre-strips find a place there. Whilst, for example, the third pre-
strip
is almost wound up, the working roll change should be concluded. It is
expected
here that after a working roll change, the finishing stand group feeding speed
for
the starting strips is higher, such as for example twice as high, as the
converted
casting speed or run-in speed into the coil store. Thus, the coil store can be
continuously reduced.
A coil store which can hold in its store for example coils with three or more
pre-
strips, would bring about even more certainty in a roll change, because it
would
make longer pauses possible.
Figures 10 and 11 show such a coil store 501 in a side view or respectively in
a
view from above. Figure 10 shows a pre-strip 502 coming from the left, which
is
wound to a coil by means of drivers 503 and a bending unit 504. On the base
side, the coil lies on a roller set 505, which is reinforced compared with the
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conventional base rollers, and is displaceable laterally by means of a
displacement unit 506. Through long winding times and/or a high coil weight,
heat-resistant or internally cooled larger base roller diameters are
necessary, in
order to withstand the stress. To support the base rollers 505, alternatively
also
additional support rollers can be swung under the base rollers.
During the winding and unwinding process, the coil store 501 or the coil 510
is
thermally insulated laterally and from the upper side. For this, covers 507
are
swung into the appropriate position. An insulation between at least individual
or
between all possible roll table rollers can also be provided.
In addition, provision is made to provide the insulating walls with burners
and to
thus actively heat the coil 510 or the coil eye 511, in order to reduce a
temperature loss. Through the winding, the scaling in the coil is reduced. If
the
burner heating arrangement is operated with a deficit of oxygen, then the
scale
formation is reduced in addition. An aspiration of the waste gases can
optionally
also be provided. During the holding time, the coil can be slowly turned or
oscillated, in order to avoid temperature strips on the coil 510 and on the
base
rollers 505.
As can be seen in Figure 10, two pre-strips 512, 513 are wound on the right-
hand coil, which pre-strips are unwound again in the unwinding position.
Unwinding devices, which are not shown, are provided for this.
In order to produce a largely uniform finishing stand group run-in
temperature,
the induction heating arrangements at the head and end of a coil can be set to
higher output or/and the pre-strip head speed during unwinding and subsequent
passage through the induction heating arrangement can be reduced.
In unfavourable conditions, in exceptional cases the outer and inner coil
winding
can be cropped away. Optionally, a driver is provided before the winding unit.
The 3-roller bending unit can alternatively be constructed as a driver or
similar
to a driver, in order to ensure a reliable winding at a low winding speed.
The jumbo coil store 501 offers the possibility, after a roll change or
generally as
a mode of operation, not to separate two or more pre-strips behind the
roughing
stand group or behind the coil store 501 at cutter S2, but rather to carry out
the
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separation of the strips before the spool at cutter S3. To reduce the energy
losses, the batch operation and especially the semi-endless operation is
preferably used. Advantageously, at least thin strips, which are critically to
be
rolled, are operated in the endless mode. In the semi-endless mode, the
rolling
can be operated advantageously at increased speed and with minimized
inductive energy supply and/or use of intermediate stand cooling.
With the inductive heating arrangement, in endless operation or in
discontinuous batch operation, the thin slab is post-heated. Here, the heat
input
can be set individually depending on the casting speed and the temperature
losses for example also within the coil store, so that with the leaving of the
thin
slab from the inductive heating arrangement, a constant temperature is
produced at the desired level. In endless rolling, the level of the casting
speed
determines the temperature profile through the entire installation. Depending
on
the casting speed, a calculation model dynamically controls the heating
outputs
of the inductive heating arrangements before and within the rolling train such
that the run-out temperature reaches the target temperature. If the casting
speed falls below a particular, predetermined threshold value, for example in
the case of problems in the casting installation, with materials which are
difficult
to cast, during the start-up process etc., then automatically a switchover
takes
place from the endless mode to discontinuous rolling (batch operation or semi-
endless operation) in the finishing stand group.
This means that the thin slab is separated by the cutter S1 and the rolling
speed
of the finishing stand group is increased so that the desired end rolling
temperature is reached. Here, the slab- or strip segments are followed within
the train and the transportation- or rolling speed and inductive heating
outputs
are adapted over the strip length dynamically depending on the temperature
distribution. If the casting process has stabilized itself again and the
casting
speed exceeds the predetermined minimum value, then in an analogous
manner a switch is carried out from the discontinuous operation back to the
endless operation mode again.
Through a free switchover or adjustment of endless or discontinuous operation,
dependent on events for example, and the presence of a buffer, a high degree
of flexibility is provided, which represents an increase in reliability of the
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process. This applies in particular when putting a production installation
into
operation.
Depending on the limiting conditions, the cutter S2 can also be arranged
before
or/and behind the coil store.
Instead of a jumbo coilbox, a heated winding furnace can also be constructed
so that two or more pre-strips find a place in a furnace. For this, the
winding
furnace is to be dimensioned so as to be correspondingly larger. Two winding
furnaces are provided for this, one over the other or adjacent to each other.
The
strip store by the winding of several pre-strips between the roughing- and
finishing stand group is therefore not limited to the coil store form which is
shown, but rather can also be designed in a structurally different way in
accordance with the invention.
The winding of the pre-strip to the coil can be carried out clockwise or anti-
clockwise, in order for example to improve the winding conditions at the low
run-
in speed.
Instead of storing several pre-strips in a jumbo pre-strip coil, the coil
store can
also consist of individual wound pre-strips. Here, the individual coils are
moved
laterally transversely into a holding furnace. Hereby, also, at least the
batch
operation and the endless operation can be realized alternatively and
sufficient
storage time is able to be provided in which a finishing train working roll
intermediate change can be carried out without interrupting the casting.
In another alternative embodiment, two or more unwinding stations are used
after the coil winding station in the transportation line. Thereby, several
coil
places, arranged one behind the other, are provided as pre-strip store.
Accordingly, individual or also jumbo pre-strips can be received.
Alternatively, it
is also possible to receive pre-strips in a carousel spool.
According to a further development of the installation according to the
invention,
in Figures 8 and 9 the installation is developed such that a temperature loss
to
the environment is to be further reduced and the installation can be
constructed
even shorter. Here, the coil store or jumbo coil store is arranged
alternatively
directly behind the roughing stand group V1,V2, which can have one to three
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stands. The cold strand at the strand head is removed here for example via the
coil store winding path upwards in this region. The heating of the pre-strip
to the
desired pre-strip temperature takes place here only behind the coil store,
i.e.
directly before the finishing train. Instead of a coil store, alternatively
one or two
or more winding furnaces can also be arranged directly behind the roughing
stands. In the region of the coil winding station 501, a plate transverse
transportation is provided, for example by means of a plate lifting unit 506
consisting of struts which are able to be lifted and/or are able to be
displaced
transversely. Here, plates with different pre-strip thicknesses are
transported to
the side, during the casting on process, when the store of the unwinding
station
is full or when otherwise space is to be provided quickly. The plates of
different
production thickness are cut by the cutter S1.
The lifting over of the coils from the winding station to the unwinding
station
during the winding process takes place for example by means of a driven
mandrel which can be moved briefly for this into the coil eye. Alternatively,
the
coil transportation from the winding station to the unwinding station takes
place
through corresponding movements of the base rollers after the cutting of the
pre-strip with the cutter S1. In order to draw a gap for this between
successive
pre-strips, the coil or the pre-strip is accelerated for this after the
separation and
the remaining pre-strip is wound more quickly.
Optionally, a descaling or a pre-strip cleaning is provided before the coil
store,
i.e. before winding. In order to keep the temperature loss small, minimal
amounts of water and a high pressure are used, such as for example in scale
washers with rotating descaling nozzles.
To balance out mass flow changes, an arrangement is provided such as a
looper or a strip loop regulator, consisting of a sagging strip region between
the
roughing train and the coil store, which is particularly helpful for thinner
pre-
strips.
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List of reference numbers
1 CSP installation
2 casting machine
3 caster outlet
4 cutter
strand
6 furnace
7 roughing stand group
8 coil store
9 straightening roller set
cutter
11 edge heater
12 finishing stand group
13 induction furnace
14 cooling section
cutter
16 winding spool
101 CSP installation
102 casting installation, casting machine
103 strand cooling device
104 slab cleaning device, cleaning device
105 slab cutter, cutter
106 cold strand removal device, - discharge device
107 roll table covering
108 furnace, furnace parts, ferries
108a ferry, ferry group
109 slab
110 scale washer
111 roughing stand group, roughing train
112 stand, roughing stand
113 coil store
114 roll table covering
115 straightening rollers
116 cutter
117 induction heating arrangement
118 finishing stand group, finishing train
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119 cleaning device, scale washer
120 finishing stand
121 heating arrangement
122 cooling section
123 strip
124 strip cutter
125 spool installation
201 CSP installation
202 casting installation, casting machine
204 scale washer
205 cutter
206 removal device
207 roll table covering
208 furnace
211 roughing train, roughing stand group
213 coil store
215 straightening roller device
216 strip cutter
217 induction furnace
217a edge heating arrangement
218 finishing stand group
219 scale washer
222 cooling section
224 cutter
225 spool arrangement
301 CSP installation
311 roughing stand group
318 finishing stand group
401 CSP installation
501 coil store, coil winding station
502 pre-strip
503 driver
504 bending unit
505 roller set
506 displacement unit, plate lifting unit
507 insulating covers
510 coil
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511 coil eye
512 pre-strip
513 pre-strip
