EP0884119A1

EP0884119A1 - Method and apparatus for coupling the casting and rolling of metals

Info

Publication number: EP0884119A1
Application number: EP98303973A
Authority: EP
Inventors: Michael Steeper
Original assignee: Kvaerner Technology and Research Ltd
Current assignee: Kvaerner Technology and Research Ltd
Priority date: 1997-06-10
Filing date: 1998-05-19
Publication date: 1998-12-16
Also published as: GB9711861D0; CA2239842A1; JPH1177110A

Abstract

The invention relates to an apparatus for the combined casting and rolling of metals comprising casting lines 12, 13 for casting a slab, corresponding receiving platform 15, 16 onto which the slab is cast, and a rolling line wherein at least one of the receiving platforms is arranged on a centre-line which is off-set from the centre of the rolling line 14 and that the slab is induced to bend and re-straighten during the transfer from the centre-line of the at least one receiving platform to the centre-line of the rolling line. The receiving platforms may be arranged a different elevation to the centre-line of the rolling line or off set to one side of the rolling line. The receiving platform may be arranged at an angle to the centre-line of the rolling line. A switching unit is provided, arranged between the receiving platforms and the rolling line in order to guide each slab from each of the receiving platforms to the rolling line in turn.

Description

The invention relates to an apparatus and method for coupling the casting and rolling of metals. In particular the invention relates to a combined apparatus and method for the continuous casting and then rolling of metals.

Typically in known systems more than one casting line is fed into a single rolling line because the rate of casting is normally slower than the rate through a single rolling mill line. Presently a transfer unit is used to transfer the slab which is produced by the casting line to a position in which it lines up with the subsequent rolling line. Such a conventional system is shown in figures 1 to 6 which show a conventional casting and rolling apparatus comprising two

casting lines

2, 3 feeding a single rolling line 4. In figure 1 the casting process in the first casting line 2 is about half way through and the casting of the second casting line 3 is about to begin. A previously cast slab is located on the transfer unit 6 ready to enter the single rolling line 4. The next stage in the process is shown in figure 2. The casting in the first casting line 2 continues, the casting of the second casting line 3 is commenced and the previously cast slab enters the rolling line 4 from the transfer unit 6. Figure 3 shows the third stage of this conventional process in which the casting of the slab on the first casting line 2 is complete and the rolling of the previously cast slab is complete. At this point the casting of the second casting line is continuing and approaching the half way stage. The transfer unit 6 is then moved to a position in line with the first casting line 2. As shown in figure 4 the slab being cast in casting line 2 is then cut at the required length and the slab proceeds onto the transfer unit 6. The length of the cast slab is determined by the length of the transfer unit 6 as well as the

casting lines

2, 3. Referring now to figure 5 the transfer unit is translated sideways (downwardly in the drawing) to line up with the rolling line 4 so that the newly cast slab can proceed to the rolling line 4 as shown in figure 6. When the rolling of this slab is complete the second casting line 3 will have been completed and a further slab will be available. The transfer unit 6 will then move sideways to a position in line with the second casting line to receive this slab and so the procedure continues.

With such conventional apparatus the length of each cast slab is limited by the length of the transfer unit 6 and the casting line is of the same corresponding length. If slabs of greater length are required then the apparatus has to be made longer with correspondingly long casting lines and transfer units. This makes the overall length of the complete line very long and this is a major prohibiting factor. Sites for such long lengths of mills are very hard to find and expensive and existing factory sites where most new equipment is desired to be located are not long enough to accommodate such long lengths of equipment. Further more the long lengths of the casting and rolling apparatus required for long slabs are expensive in terms of the physical cost of the apparatus itself as well as the factory space it takes up.

It is therefore an objective of the invention to provide a combined casting and rolling apparatus for metal which is shorter in length than conventional casting and rolling apparatus.

It is also an objective of the present invention to provide a continuous casting and rolling apparatus which can produce longer lengths of slabs and consequently longer runs through the rolling line.

According to the invention there is provided an apparatus for the combined casting and rolling of metals comprising at least a first and second casting lines for casting a slab and a rolling line; each casting line also comprising a corresponding first and second receiving platform onto which the slab is cast, characterised in that at least one of the at least first and second receiving platforms is arranged on a centre-line which is off-set from the centre of the rolling line and that the slab is bent during the transfer from the centre-line of the at least one receiving platform to the centre-line of the rolling line.

The at least one receiving platform is preferably in the form of a tunnel furnace in this embodiment in which the temperature of the cast slabs can be controlled and maintained by heat retaining means and with heat adding means. They will however be referred to merely as receiving platforms henceforth in this description.

The at least one receiving platform may be arranged on a centre line at a different elevation to the rolling line, preferably higher than the rolling line. Alternatively the at least one receiving platform may be arranged on a centre-line which is off-set to one side of the rolling line.

The centre-line of the at least one receiving platform may be arranged at an angle to the centre-line of the rolling line.

Preferably a switching unit is provided arranged between the receiving platform and the rolling line in order to guide each slab from each of the receiving platforms to the rolling line in turn. The switching unit may be a tilting unit which is pivotable between a first position in which it connects the first receiving platform to the rolling line and a second position in which it connects the second receiving platform to the rolling line.

The switching unit may alternatively be a fixed roll incline unit which comprises two sets of at least one roll guide a first set which is arranged to connect the first receiving platform with the rolling line and a second set which is arranged to connect the second receiving platform to the rolling line.

The switching unit is preferably arranged close to the rolling line.

Preferably at least one receiving platform is arranged to be in line with the rolling line. Alternatively each receiving platform may be arranged to be off-set from the rolling line

Preferably the switching unit is a deflection unit which deflects the slab sideways into line with the rolling line. Preferably the deflection unit comprises driven rolls for sideways movement of the slab. Preferably the deflection unit comprises inclined rolls for the sideways movement of the slab.

The at least one receiving platform may be arranged to be both at a different elevation to the rolling line and off-set sideways to the centre line of the rolling line.

According to the invention there is also provided a method of casting and rolling of metal comprising at least one casting line and a rolling line and at least one receiving platform corresponding to the at least one casting line arranged between them, said casting line being on a different centre-line to the rolling line, wherein a slab is cast on the receiving platform on a centre-line thereof and is translated from this centre-line of the receiving platform to the centre-line of the rolling mill by a continuous bending of the slab.

Exemplary embodiments of the method and apparatus of the invention will now be described with the assistance of the following drawings which include drawings of a prior art apparatus already referred to and in which:

figs. 1 to 6 are schematic views of six steps of a casting and rolling method and apparatus of the prior art,

figs. 7 to 14 are schematic views often steps of a casting and rolling method and apparatus of an embodiment of the invention.

fig. 15 is a side elevation of an alternative embodiment of the invention,

fig. 16 is a schematic plan view of a further embodiment of the invention,

fig. 17 is plan view of the embodiment of fig. 16 showing the guide rolls,

fig. 18 is a side view of the embodiment of fig. 16,

fig. 19 is an end view of the embodiment of fig. 16, and

fig. 20 is a general arrangement of the whole apparatus in plan view of the embodiment of fig. 16.

The method and apparatus of the prior art shown in figures 1 to 6 has already been discussed above.

Referring to figures 7 to 14 the embodiment of the invention is shown in which there is provided an apparatus 1 for the combined casting and rolling of metals comprising at least two

casting lines

12, 13 and a rolling line 14 each

casting line

12, 13 also comprising a corresponding

receiving platform

15, 16 onto which the slab is cast. At the end of the receiving platforms a tilting unit 17 is located which may be pivoted from a position in which it is connects the upper receiving platform 15 with the rolling line 14 and a position in which it connects the lower receiving platform 16. The lower casting unit 13 is located in a position which is off-set further back from the upper casting unit 12. This is for operational convenience and to aid with access to the two casting units for maintenance.

Referring to each step in tum it can be seen from figure 7 that the apparatus and method of this embodiment of the invention is shown in which a first slab has already been cast on the lower receiving platform 16 and is being fed into the rolling mill 14 by the tilting unit 17 which is in a lower untilted position connecting the lower receiving platform 16 with the rolling line. The first, upper, casting line 12 is about halfway through the casting of a second slab on its receiving platform 15 which is in line with the first casting line 12.

The upper and

lower receiving platforms

15,16 are preferably in the form of tunnel furnaces in this embodiment in which the temperature of the cast slabs can be controlled and maintained by heat retaining means and also heat adding burners or electric heating elements. For simplicities sake they will be referred to as receiving platforms throughout the description.

Figure 8 shows the procedure continuing and the commencing of the casting of a third slab on the lower receiving platform 16.

Referring to figure 9, as soon as the end of the first slab passes the tilting unit 17, the tilting unit 17 is pivoted upwardly to connect the receiving platform 15 to the rolling line 14 and guide the second slab into the rolling line 14. Figure 10 shows the tilting unit 17 in the upwardly pivoted position connecting the upper receiving platform 17.

Referring now to figure 11 the second slab has now reached the tilting unit 17 and falls by bending under gravity down the incline of the tilting unit towards the rolling line 14. This second slab may alternatively be driven downwards with appropriate guiding means which does not rely on gravity or only partially relies on gravity. At this stage the desired length of the slab has been reached and the slab is cut at the casting end of the receiving platform. The second slab then proceeds into the rolling line 14 as shown in figure 12, 12a and 12b.

In figures 13 the second slab has continued into the rolling line until its rearmost end has passed the tilting unit 17. A fourth slab is in the meantime being cast behind it on the upper receiving platform 15 and the third slab is now approaching the end of the lower receiving platform 16. As shown in figure 14 the tilting unit is at this point pivoted downwardly to its level position again connecting the lower receiving platform 16 with the rolling line 14. The cycle is thus repeated potentially indefinitely.

Referring now to figure 15 an alternative embodiment is shown in which the tilting unit is replaced by an alternative unit for switching the slabs from the receiving platform to the rolling line. In this embodiment an incline unit 18 is provided which comprises two sets of rolls, a first incline set 19 which is inclined from the level of the upper receiving unit 15 to the rolling line 14 and a second flat set 20 which connects the lower receiving unit with the rolling line 14. Thus when a slab is arriving from the upper receiving platform 15 it is guided down the incline rolls 19 in a controlled way to the rolling line 14. Similarly when a slab arrives from the lower receiving platform 16 it is guided in a controlled way along the flat rolls 20 to the rolling line 14.

An alternative embodiment of the invention is shown in figures 16 to 18. Figure 16 shows a plan view of the general schematic arrangement comprising, as with the previous embodiment, two casting

units

22, 23 each with a corresponding receiving platform or

tunnel furnace

25, 26. In this embodiment the casting units are not arranged one above the other but side by side.

The first casting unit 22 is arranged to be in-line with the rolling line 24 and the second casting unit 23 is off-centre with respect to the rolling unit 24. A switching unit is arranged at the end of the second, off-line receiving platform 26 which is in the form of a deflection unit 27 for the deflecting the slabs cast on the off-line receiving platform 26 to be aligned with the rolling line 24. Although this embodiment includes one of the casting units 22 in line with the rolling line 24, it could also be advantageous, in an alternative embodiment to have both of the casting

units

22, 23 off-line with the rolling line 24 by equal amounts so that only half of the deflection is required for each slab.

The sequence of the casting procedure is as described for the first embodiment above. Referring to figure 17 deflection rolls 28 of the deflection unit 27 are shown which are arranged at an angle to the axis of the standard rolls in order to create the desired deflection.

Figure 18 shows the end view of the deflection unit 27 and the corresponding position of the deflection rolls 28

Referring now to figure 19 a further side elevation is shown of an alternative embodiment of the deflection unit with the rolls 28 angled upwardly as well as inwardly. Thus in this embodiment there is a combination of the sideways displacement and the vertical displacement of the receiving platforms or tunnel furnaces. This embodiment is shown schematically in the plan view in figure 20 with the off-line casting unit having two receiving

platforms

36a, 36b separated by the deflecting unit 27. The second receiving platform 36b is arranged in an elevated position and a further tilting unit 29 is arranged at the end of this receiving platform in order to guide the slabs into the rolling line as previously described.

It will be appreciated that by means of the invention a considerable reduction in the overall length of the production line is achieved which has considerable consequential benefit in terms of the cost of the apparatus itself and in the cost of the space required. Furthermore longer slabs are able to be cast using the method and apparatus of the invention from a mill of a given total size.

It will also be appreciated that the invention is not limited to the examples described above but is intended to include any other embodiment within the concept of the invention as defined in the appended claims.

Claims

An apparatus for the combined casting and rolling of metals comprising at least a first and second casting lines 12, 13 for casting a slab and a rolling line 14; each casting line 12, 13 also comprising a corresponding first and second receiving platform 15, 16 onto which the slab is cast, characterised in that at least one of the at least first and second receiving platforms is arranged on a centre-line which is off-set from the centre of the rolling line 14 and that the slab is induced to bend and re-straighten during the transfer from the centre-line of the at least one receiving platform to the centre-line of the rolling line.
An apparatus according to claim 1, characterised in that the at least one receiving platform is arranged on a centre line which is at a different elevation to the centre-line of the rolling line.
An apparatus according to claim 1, characterised in that the at least one receiving platform is arranged on a centre-line which is off set to one side of the rolling line.
An apparatus according to claim 3, characterised in that at least one receiving platform is arranged on a centre line arranged at an angle to the centre-line of the rolling line.
An apparatus according to claim 1, characterised in that the at least one switching unit is provided, arranged between the receiving platforms and the rolling line in order to guide each slab from each of the receiving platforms to the rolling line in turn.
An apparatus according to claim 5, characterised in that the at least one switching unit is a tilting unit which is pivotable between a first position in which it connects the first receiving platform to the rolling line and a second position in which it connects the second receiving platform to the rolling line.
An apparatus according to claim 1, characterised in that the at least one switching unit is a fixed roll incline unit which comprises two sets of rolls each having at least one roll guide, a first set being arranged to connect the first receiving platform with the rolling line and a second set which is arranged to connect the second receiving platform to the rolling line.
An apparatus according to claim 1, characterised in that the at least one switching unit is a deflection unit which deflects the slab sideways into line with the rolling line.
A method of casting and rolling of metal comprising at least one casting line and a rolling line 14 and at least one receiving platform corresponding to the at least one casting line arranged between them, said casting line being on a different centre-line to the rolling line, wherein a slab is cast on the receiving platform on a centre-line thereof and is translated from this centre-line of the receiving platform to the centre-line of the rolling mill by a continuous bending of the slab.