Note: Descriptions are shown in the official language in which they were submitted.
314~
The invention relates to ~n apparatus for dividing a strand into
slabs with a device for dividing said strand transversely
arranged after the strand guide (roller apron) and with a
device for dividing said strand longitudinally, and to a method
of operating said device.
The invention relates particularly to the division of a steel
strand into slabs.
In conjunction with steel continuous casting plants it is pro-
posed in the Japanese-Offenlegungsschrift 50-128 628 to divide
the strand longitudinally by flame cutting directly subsequent
to the roller apron and then to divide the strand transversely.
In the case of this proposal the strand is divided longitu-
dinally when hot and ~hen divided transversely. This construction
does not guarantee an exact longitudinal division with desired
division proportion for various reasons. One is that it is
difficult to alter the division proportion during continuous
casting when the strand is being continuously extracted. More-
over, exact straightening of the strand longitudinally is not
guaranteed as the continu~usly extracted strand does not always
assume exactly the same position. The specialists have there~ore
preferred to divide excessively wide slabs longitudinally when
cold. A corresponding proposal is known from the publication
"Concast News" 13 (1974,pages 6 and 7). The advantages of lon-
gitudinal division of cold slabs are regarded as being that less
slag and fumes are produced on division and that the cycle time
of longitudinal division is independent of the casting speed.
The disadvantage of these known plants is that they need a sub-
stantial amount of space and often additionally need an intensive
cooling plant in order to cool the slabs, which have been cut
into lengths, quickly down room temperature.
The object of the present invention is to develop a device for
dividing a strand into slabs which guarantees a quick and exact
longitudinal division even with high casting speeds at the same
time being low in apparatus costs and having a simple construction.
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This object is solved according to the invention in that the
transverse dividing device has at least two longitudinal di-
viding devices arranged thereafter, to which the cut olf slab
can be guided selectively by means of at least one transport
means. A common transport means is preferably provided for all
the longitudinal dividing devices. A favourable arrangement
as to space is hereby achieved if the common transport means is
in the form of a ~ransverse transporting device. It is expe-
dient to arrange the longitudinal dividing devices in the
proximity of or at height of the run-out rol]er table allocated
to the strand. In a particularly advantageous embodiment the
longitudinal dividing devices are arranged parallel to the
run-out roller table. The aforementioned constructions have
the advantage that even at high casting speeds the longitudinal
division can be carried outin a very short time after the trans-
verse division, whereby the slab must merely be conveyed to
the respective free longitudinal dividing device by means of
the transport device after transverse division. As the trans-
verse dividing device, the run-out roller table, the transport
device and the longitudinal dividing devices are arranged very
closely together, the entire plant is space-saving and con-
structionally simple.
A particularly advantageous embodiment is characterised in that
the individual longitudinal dividing devices, which are each
equiped with at least one flame cutting means, have a cutting
point ope~ng allocated to and below the flame cutting means on
(in) the slab bearing area and a transverse shifting means on
the longitudinal side of the slab bearing surface on at least
one of the two longitudinal sides. The slab is laterally
straightened with the aid of the transverse shifting means. In
order to set the exact division proportion over the width of
the slab, the cutting torches can be either transversely
shiftable or assembled so as not to be shiftable in transverse
direction. Torches which are not shiftable in transverse
direction are preferred if, at the same time, the cutting point
opening allocated thereto on (in) the slab bearing area is
fixed (stationary). In conjunction with this construction it
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is particularly advantageous if the transverse shifting means
ls in the form of a centering means which centres and shifts
the slabs respective to the (fixed) cutting point opening in
transverse direction of the longitudinal dividing device. This ~ -
centering means arranged on the longitudinal side is, for
expedience, composed of at least a transverse shifting means
arranged on the longitudinal side and a transversely shiftable
abutment along the other longitudinal side of the slab, so
that the division proportion can be adjusted exactly to the
cutting torches and the (fixed) cutting point op~ing. For this
slab merely needs to be shifted with the aid of the centering
means. The transversely shiftable centering means is in abutting
relationship with the longitudinal side of the slab, i.e. it
is arranged vertical to the broad side of the slab. The centering
means can be stopped after the slab has been centred. The
longitudinal dividing device has therefore only few parts
which are mobile during operation and therefore it is guaranteed
that the slabs can be divided longitudinally with the aid of
this device in the desired division proportion and very
accurately.
A construction which is to be emphasized is one ~ which the
cutting point op~ing is in the form of a narrow gap which feeds
into a channel receiving the waste material. With this con-
struction the waste material can be easily removed. It is par-
ticularly advantageous in this construction if a suction device
for removing the fumes is attached to the channel. It has been
seen that besides the slag produced approx. 90% of the fumes
produced arise below the slab and therefore by using the suction
device almost all the disturbing fumes can be removed. If the
cutting point opR~ng formed as a gap is not particularly large,
there is the advantage that only a small proportion of infil-
trated air (false air) is also sucked off. It is thereby possible
that the problem of waste gas can be effectively dealt with
even with relatively low suction performance of the suction
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device. This aim is realised in an even better way if - apart
from the necessary cutting point opening - the channel can be
closed for the most part in order to minimise the penetration
o~ infiltrated air. Expedient solutions for this are explained
in connection with Figs. 3 and 4.
,i
According to one embodiment the cutting torch and the cutting
point opening are fixed in both transverse and longitudinal
direCtion of the device, whereby the slab is pushed over the
cutting point opening in lQ~itudinal direction for division
longitudinally. The slab is thereby guided longitudinally by
the stopped (secured) centering means. In this construction the
cutting point op~ing and the channel situated below it are re- -
stricted in longitudinal direction of the device to a narrow
space so that the slag produced in this space can be easily re-
moved. It is pre~erred in this construction that on a single
cutting torch is used in order to guarantee a smooth cut edge
without any faults.
According to another preferred embodiment the cutting point
opening in the form of a gap and the channel connecting there-
with extend pra~ically over the entire length of the longitudinal -
dividing device below the slab bearing area, whereby for expe-
dience two flame cutting devices, which are movable longitu-
dinally in opposing direction, are arranged above the slab
bearing area for dividing the slab longitudinally. This con-
struction guarantees that the slab is divided quickly in longi~
tudinal direction, i.e. in almost half the time, whereby at the
same time slag and fumes are removed simply. As an alternative
to the channel provided over the entire length of the longi-
tudinal dividing device it is also possible to provide a (bucket)
tub, for example, which can be moved in the conceived gap direc-
tion, i.e. a much shorter slag collecting device, whereby the
feed motion of the tub must be coordinated with the feed motion
of the cutting torch. The construction with the movable tub
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11~314~
be used advantageously when the slab lies securely on the
bearing area during the entire flame cutting processl i.e. the
slab does not work too hard during the flame cutting.
The device according to the invention is preferably operated
in such a way that the slabs which have been cut in lengths
from the strand by transverse division are conveyed to one of
the longitudinal dividing devices directly out of the casting
heat at surface temperatures of over 300 C. Longitudinal di-
vision at surface temperatures of over 500 C is preferred. It
was namely observed that the formation of sabre-shaped longi-
tudinal sides of the slab can be avoided by maintaining the
surface temperature as high as possible during longitudinal
division. Conversely, the Applicant has established that at
slab temperatures of approx. 150 to 250 ~ the slabs tend to
distort outwardly in the form of a sabre - working from the flame
out line - so that further treatment of the divided sabre-shaped
slabs is made more difficult.
In order to guarantee the highest possible surface temperature,
it has proved advantageous that the slab cut from the strand is
moved on without delay after transverse division and is divided
longitudinally pra~ically without temporal delay. This quick
longitudinal division is possible due to the allocation according
to the invention of transverse dividing device, run-out roller
table, transport means combined with several longitudinal divi-
ding devices. The subject of the invention is particularly suited
for dividing continuously cast slabs for magnetic sheet materials
with a silicon content of~ o.6 %, preferably ~ 1.5 % Si.
The particular advantages of the subject of the invention are
to be seen in that very quick longitudinal division is possible
at the highest possible slab temperature with a low cost in
apparatus. Slabs which are narrower and in particular variable
in width can be cut from excessively wide continuously cast slabs.
This cut slabs are particularly favourable as starting product
for rolling mills and the desired sheet widths. In continuous
casting the advantages of sequence casting can be used as quick
and exact longitudinal division is possible with the construction
_
: ,
~1~3~L4~
according to the invention. The advantageous embodiments of the
longitudinal dividing devices specified in sub-claims additio-
nally guarantee that no problems arise due to slag or fumes
as the fumes and working material losses produced can be removed
without at a low constructional cost without impaiting the
environment. The subject of the invention offers the additional
advantage that the longitudinally divided slabs are still so
hot that the remaining heat in the slab can be utilised for the
subsequent reheating up to rolling temperature. The s~bject of
the invention permits the longituAinal division of continuously
cast slabs when still hot, i.e. out of the production flow of
the continuous casting plant, with a high degree of accuracy.
The invention is explained below in greater detail by means of
an embodiment.
Fig. 1 shows a top view onto an entire plant with
several longitudinal dividing devices,
Fig. 2 shows a top view onto one of the longitudinal
~ dividing devices,
Fig. 3 shows a longitudinal section through the
longitudinal dividing device according to
III-III of Fig. 2 and
Fig. 4 shows a cross-section through the longitudinal
dividing device according to IV-IV of Fig.2.
Fig. 1 shows the part of a twin strand slab continuous casting
plant arranged after the roller apron strand guiding (not shown),
each with a transverse dividing device 1 and the connecting run-
out roller table 2. The run-out roller tables 2 are connected
selectively with one of four longitudinal dividing devices 5 by
means of a joint transverse transport means 4. The connection
between the run-out roller tables and the transverse transport
means 4 is provided by the transfer 3. The slabs produced after
transverse division can be moved off from the run-out roller
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tables 2 individually by the transfer 3 and conveyed to the
transverse transport means 4. In the shown example a transport
car wh:ich can be moved on rails is provided as transverse trans-
port means. The fourlongitudinal dividing devices 5 are p~lLallel
and adjacent to one another at about the height of the section
of the run-out roller tables 2 which extend behind the trans-
verse dividing devices 1 of the continuous casting plant. This
offset construction method of longitudinal dividing devices 5
and run-out roller tables 2 provides a compact arrangement,
whereby a quick transporting of the slabs to and possibly also
off the longitudinal dividing devices 5 is guaranteed with only
one common transverse transport means.
As Figs. 2 to 4 show, each longitudinal dividing device 5 has a
slab bearing surface 50 and at least one flame cutting means lo.
The slab bearing area 50 has a gap-like cutting point opening
51 below the flame cutting means lo. The gap-like cutting point
opening 51 extends practically over the entire length of the
longitudinal dividing device and is arranged, looking at it in
transverse direction, approximately in the middle of the longi-
tudinal dividing device. The transversely shiftable centering
means 20 is positioned on one longitudinal side of the longi-
tudinal dividing device 5. The pressing device 25 is provided
as abutment on the other longitudinal side of the slab.
Individually, Fig. 2 and 3 show that the longitudinal dividing
device 5 preferably has six rollers 53 arranged one behind the
other for transporting the slab on and off said longitudinal
dividing device 5, whereby the feed motion of the slab is re-
stricted at the front side by a fixed stop 54. The rollers 53,
i.e. individually actuated rollers which are cooled inside,
are swung away forwards and downwards in a way known per se
after the slab has been transported (see dotted position of
rollers in Fig. 3). When the rollers 53 have been swung away
the slab rests on a plurality of bearing elements 55 which
7 - ,l
lla3~4~
are arranged one behind the other to forM the slab bearing
area 50. This slab bearing area 50 on the individual bearing
elements 55 are divided in the middle in longitudinal direction
by the gap-like cutting point opening 51. Thereby the width
of the cutting point opening 51 amounts at least to about
loo mm in transverse direction of the longitudinal dividing r
device 5. According to Figs.2 and 3 a total of six bearing
elements 55 arranged one behind the other are provided.
The flame cutting means with lo as reference for the whole is
situated above the bearing elements 55. The flame cutting
means is composed of two torch cars 13 and 14 each equiped with
cutting torches 15,16. Each torch car 13~14 is individually
actuated. During the flame cutting the torch cars are moved
towards each other with a feed motion corresponding to the flame
cutting speed. The cutting torches 15,16 are positioned in the
.
11~3~44
middle of the car and are assembled so securely on the
torch car 13, 14 in transverse direction of the longitudinal
dividing device 5 that they move towards each other during
the flame cutting on a straight line, the so-called flame
cutting line. This flame cutting line overlaps the
gap-like cutting point opening 51 position underneath it.
In order to set the desired width, into which the s]ab resting
on the slab bearing area 50 is to be divided longitudinally,
the centering means 20 is provided on one side Of the bearing
area 50. The centering means 20 is composed of a ruler-type
beam 21 which is armed with rollers 22 and runs parallel to the
longitudinal axis of the longitudinal dividing device 5.
With the assistance of the worm gear 24 actuated by motor 23
the beam 21 can be pushed transversely to the longitudinal
axis of the longitudinal dividing device 5 and then brought
to a fixed position. In the shown preferred embodiment pressing
devices 25 are provided on the other longitudinal side of the
slab bearing area 50. These pressing devices 25 are composed
of a rotatable lever 26 which stri-kes the floor of the
longitudinal dividing device 5 and which can be operated by
a hydraulic cylinder 27. After the desired widths into which
the slab is to be divided longitudinally have been set
with the assistance of the centering means 20, the slab
is pressed by means of the pressing device 25 against the beam
21 which serves as an abutment. Exact centering of the slab is
hereby guaranteed.
Fig. 2 shows that the cutting point opening 51 as narrow gap
practically extends over the whole of the length of the
longitudinal dividing device 5. As the cross-section in
Fig. 4 shows, the gap-like cutting point 51 opening feeds into
a channel 28 which is only open to the top over the entire
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1~3~44
.. .
length of the longitudinal dividing device 5. The channel ;
28 has side walls 29 Or heatproof sheets Or metal. As Fig. 3
shows, these side walls 29 have recesses 31 which-are Pormed
according to the swing path of the rollers 53 (to the
right in Fig. ~). When the rollers have been
swung to the right, the recesses 31 for the rollers 53
are closed by shutter plates 32. The channel 28 is closed
off to the bottom by a j;gging conveyor 33 by w~ich the slag
produced during flame cutting is conveyed on or in a
transport means 34, e.g. on a chute or in a tub.
Fig. 4 shows that conduits 35 feed into the channel 28 at
about the middle of the side walls 29, whereby the conduits
35 are attached to a suction conduit 36 which runs parallel
to the channel 28. The suction conduit 36 feeds into a --
dedusting plant 44 (see Fig. 1). The shown construction
has the advantage that a good removal of slag by suction
is guaranteed with relatively low activity. The shutter ~~-
plates 32 contribute to this; they close the recesses 31 in - -~
the side walls 29 of the channel 28 during the flame cutting.
Furthermore, the upper edge of the side walls 29 extends as
far as possible, i. e. up to a distance of approx 20 mm,
up to the upper edge of the bearing elements 50, so that
when the slab lies thereon only a small amount of infiltrated ~-;
air can be sucked. If a short slab i5 lying on the slab
bearing area 55, the part of the cutting point opening 51 which
is not covered by the slab is open at the top. As too much -~
infiltrated air could be sucked in this case, there is the
favourable possibility of clos-ing the channel 28
corresponding to the length of the slab segment by segment
from one or from both ends, so that only the part underneath
the slab is opened.
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31~4
To reduce the proportion of penetrating infiltrated air further
it is preferred to drive towards or onto the suction conduits
35 in coordination with the cutting. Only the suction conduits
are open respectively and thereby functioning at what level
the flame cutting devices are positioned.
' :
The working method of the device is as foliows:
The slab which is cut in lengths from the strand by means
of a transverse dividing device 1 is transferred from the trans-
fer 3 to the transverse transport device 4. The transverse
transport device 4 in the form of a transport car is preferably
armed with a roller table 9. The transport car 4 then moves -
with the slab to one of the four longitudinal dividing devices 5.
When the roller table of the transport car 4 is switched on the
slab is moved in longitudinal direction onto the roller table -
53 of the longitudinal dividing device 5 so that the longitu-
dinal division can begin. After longitudinal division has been ~-
completed the divided slabs are preferably collected by a
second transport car 6 which is also armed with a roller -
table 8 and brought to a lifting truck 7 which singles out ~`
the divided slab sections.
In the area of each longitudinal dividing device 5 the slab -~
moves starting from the roller table 9 of the transport car 4,
over the roller table of the longitudinal dividing device 5
until it rests against the stop 54. The rollers 53 are dropped
and the recesses 31 are closed by the shutter plates 32.
The slab now rests on the bearing area 50. The rollers 53
can revolve further when dropped in order to prevent the
slag caking.
The slab is now brought into cutting position by the cente-
ring means 20. For this purpose the slab is shifted transver- =
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sely by means Or the ruler-like beam 21 of the centering
means 20 to the middle of' the longitudinal dividing device
5 until the distance between the flame cutting line and the
beam 21 corresponds to desired dividing width (e.g. two-part slabs
with dividing widths 2/5 and '3/5 of the excessively wide slab).
The beam 21 is then secured in this position. The slab is
then pressed by means Or the pressing device 25 against
the beam 21 which serves as an abutment. Arter this
straightening process the beam 21 and the pressing device 25
can be moved back to their starting positions.
For the actual flame cutting process the torch cars 13,14
move towards each other with a predetermined feed motion.
They meet at approximately the middle of the torch stretch.
Before they reach the middle one of the torch cars 13 or 14 ',
stops its course and moves back to the starting point
whilst the other torch car completes the cutting. The slag
produced falls freely into the channel 28 beneath the slab
bearing surface 50 and is transported to be tub 34 by the
jigging conveyor 33. The fum-es are sucked through
the suction conduits 35, 36 up to the dedusting plant 44.
It has been shown that about 90 % of the fum-es produced
can be removed in this way. The f'urnes produced above the slab
can be caught with the aid of a hood (not shown) and also
conveyed to the dedusting plant by means of a conduit.
This application is a divisional application of our copending
application Serial No. 298,670.
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