Device for the alternate winding-up and unwinding of strip-shaped material

A device for the alternate winding-up and unwinding of strip-shaped material, particularly strand-cast thin slabs in furnace pairs, consisting of two furnaces that are located one above the other and have horizontal winding axles, in which the furnaces can be swung from a winding-up position in an unwinding position and the winding-up and unwinding take place at different speeds. To permit winding-up in one of the two furnaces and unwinding in the other furnace to occur simultaneously and in different directions, each furnace of a furnace pair is pivotable around a vertical axis independent of the other furnace.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a device for the alternate winding-up and 
unwinding of strip-shaped material, particularly strand-cast thin slabs in 
furnace pairs, consisting of two furnaces that are located one above the 
other and have horizontal winding axles. In which device the furnaces can 
be swung from a winding-up position into an unwinding position and 
winding-up and unwinding take place at different speeds. 
2. Description of the Prior Art 
A generic winding device is known, for example, from DE 40 13 582 C1. This 
device is integrated into a unit which produces a hot-rolled strip of 
strand-cast input material, and it serves to compensate for the 
differences in speed between the strand casting and the rolling by 
temporarily storing the strip. The winding-up of the strip occurs in 
furnaces, so that uniform temperature conditions are achieved for the 
subsequent processing of the strip, which is then unwound from the 
furnaces, in the downstream finishing rolling mill. 
Another winding device with furnaces located one above the other is known 
from EP 01 77 187 A1. In this device, in a manner similar to that known 
from DE 40 13 582 C1, the furnaces are alternately used for winding-up the 
strip, and the furnace which is not being used at a given time for 
winding-up the strip feeds the rolling mill by unwinding the previously 
wound-up strip. 
The generic solution calls for the furnaces to be closed to large extent, 
in order to minimize heat loss during the winding-up and unwinding of the 
strip. 
Both of the solutions described above require the strip-shaped material 
being wound-up, such as the strand-cast thin slab, to be fed in the same 
direction as the direction in which the unwound material is borne away, 
i.e., the rolling mill must be aligned with the upstream unit, which may 
be a thin-slab casting machine or the roughing train of a wide-strip 
train. However, space conditions often do not permit these two elements to 
be lined up in a straight line in front of and behind the furnace, 
particularly when existing units are being rebuilt. In such cases, the 
known winding-up and unwinding devices cannot be used. Although the idea 
of providing furnace pairs, each of which consists of two furnaces located 
one above the other on a shared rotary table is known from DE-PS 972 603 
(FIGS. 3 and 4), which would theoretically allow the winding-up and 
unwinding sequences to be carried out in different directions, the furnace 
pairs in the known solutions are attached to the shared rotary table in 
such a way that while winding-up is in progress, unwinding in a different 
direction is not possible. 
SUMMARY OF THE INVENTION 
Starting from this prior art, it is an object of the present invention to 
provide a device for the alternate winding-up and unwinding of 
strip-shaped material which permits winding-up to occur in one of the 
furnaces while, simultaneously, unwinding occurs in the other furnace in a 
different direction. Pursuant to this object, and others which will become 
apparent hereafter, one aspect of the present invention is that each 
furnace in a furnace pair is pivotable around a vertical axis independent 
of the other furnace. 
Thus, the present invention departs from the prior art in which, even 
though two furnaces are pivotable independent of each another, pivoting 
occurs around horizontal axes corresponding to the winding axle. The 
present invention makes it possible, in a surprisingly simple manner, to 
wind up a strip in one of the furnaces while simultaneously performing an 
unwinding sequence in a different direction in a different furnace, which 
has been pivoted around a vertical axis. Thus a furnace pair of the 
invention can connect, for example, a thinslab casting machine and a 
downstream finishing train which are located at an angle to one another. 
It is preferable to have both furnaces pivot around a common axle. When the 
axle around which the furnaces can be swung intersects the winding axle at 
the winding axle's midpoint, the final pivot positions will always be 
correct for attaching the upstream or downstream parts of the unit. 
A further embodiment of the invention calls for a horizontal passage 
between the furnaces for strip-shaped material that is not to be wound. 
The fact that each furnace is designed as a self-contained element, in 
order, as mentioned earlier, to minimize heat loss, also means that it is 
possible to convey between the furnaces any strip-shaped material which, 
for some reason, is not to be wound up. 
In another embodiment of the invention, each furnace can be swung by 90 
degrees between the winding-up and the unwinding positions. 
With the features described above, the invention, in a particularly 
advantageous manner, permits a furnace pair to be located behind each 
strand of a multi-strand thin-slab casting machine and in front of a 
common finishing train, while horizontal conveyor tables for the 
strip-shaped material are provided between the two furnace pairs and 
simultaneously between the two furnaces of the furnace pair closer to the 
finishing mill. 
The invention, with furnaces that can be pivoted independently around 
vertical axles, makes it extremely simple to connect a plurality of 
strands from a casting machine to a single finishing train. To accomplish 
this requires that the finishing train be located at right angles to the 
multiple casting strands (two or more) and that each furnace be pivotable 
into a position aligned with the casting machine and a position aligned 
with the finishing train. The furnace pairs of the individual casting 
strands are located one behind the other in the direction of the finishing 
train so that the strip-shaped material that is unwound from the furnace 
pair farther away from the finishing train can be conveyed through the 
passage which exists between the furnaces of the furnace pair adjacent to 
the finishing train. In this way, it is very simple to connect different 
casting strands to one another, whereby, according to another feature of 
the invention, the conveyor tables are preferably housed in a fashion that 
is at least partially heatinsulating. 
It has been found that an especially advantageous solution includes 
accommodating each furnace of a furnace pair in a carrying rack which is 
attached in a rotatable fashion to a rotating ring having a center axis 
that corresponds to the pivot axis of the furnaces. 
The inventive device provides a further advantage by virtue of the fact 
that the furnaces pivotable around vertical axles can be equipped with 
permanent chimney connections if these connections are attached rotatably 
to the furnaces concentric to the oven pivot axles. When chimney 
connections existed in the prior art, it was necessary to detach these 
connections prior to pivoting and to reconnect them again after pivoting. 
This was disadvantageous for reasons of environmental protection. 
An example of the invention is described below in reference to a two-strand 
thinslab casting machine with a downstream finishing mill. 
The various features of novelty which characterize the invention are 
pointed out with particularity in the claims annexed to and forming a part 
of the disclosure. For a better understanding of the invention, its 
operating advantages, and specific objects attained by its use, reference 
should be had to the drawing and descriptive matter in which there are 
illustrated and described preferred embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIG. 1, the reference numbers 1, 2 indicate thin-slab casting machines 
located parallel to one another in which preshaped input strip is 
produced. After inductive heating 3, 4 and homogenization, the strip is 
fed to a furnace pair 5, 6, where the strip-shaped material is reeled up 
in one of the two furnaces which are located one above the other. 
In the other furnace of each of the furnace pairs 5, 6, the strip-shaped 
material that has been wound-up is brought, after the furnace has been 
swung by 90 degrees, into its unwinding position and is unwound in the 
direction of the finishing train 7. The strip-shaped material is conveyed 
from the furnace pair 5 via the housed conveyor table 8 arranged between 
the furnaces of the furnace pair 6 and is thus able to pass without 
obstruction into the finishing mill 7. 
FIG. 2 is a rough diagram showing the arrangement of the two furnace pairs 
5, 6. The furnaces of furnace pair 5 are indicated by 9 (upper furnace) 
and 10 (lower furnace), while the furnaces of furnace pair 6 are indicated 
by 11 and 12. Each of the furnaces 9 to 12 is located in a carrying frame 
13 and can be pivoted on circular tracks 14 around the vertical axis 15. 
The furnaces 9, 10 as well as the furnaces 11, 12, respectively, are shown 
pivoted by 90 degrees relative to each another, corresponding to their 
winding-up and unwinding positions. When, for example, a strip of the 
strip-shaped material is being wound up in furnace 9, as indicated by 16, 
around the horizontal winding axle 17, the strip that has been wound 
around the winding axle 18 can be unwound out of furnace 10. The 
strip-shaped material "B" is conveyed via the housed conveyor table 8 
between the furnaces 11 and 12 of the furnace pair 6 to the finishing 
train 7. Meanwhile, a strand coming from the thin-slab casting machine 1 
or 2 can be wound up in one of the furnaces 11 and 12, just as in furnace 
9. 
In the same way, it is also possible to connect a plurality of casting 
strands with each other, so that an extremely flexible unit can be created 
by very simple means. Naturally, the application of the invention is not 
limited to thin-slab casting machines with downstream finishing trains. 
Wide-band trains can also be improved in an advantageous manner with the 
device according to the invention. 
In addition to permitting rotation, the separate accommodation of the 
furnaces 9 to 12 in the carrying frame 13 makes it possible for an entire 
furnace unit to be moved out laterally into a maintenance position outside 
the train, so that repairs can be carried out on one of the furnaces 9, 10 
or 11, 12 of the furnace pair 5 or 6 while the remaining furnace is used 
to maintain operations at reduced output. 
The suggested device as well as a unit equipped with this device is 
distinguished by particular simplicity in design and in control. The space 
that can be saved by the invention is significant in respect not only to 
the size of the unit, but also to the thermal conditions, because the 
losses between individual unit parts become lower as the unit becomes 
shorter. 
The invention is not limited by the embodiments described above which are 
presented as examples only but can be modified in various ways within the 
scope of protection defined by the appended patent claims.