EP2259886B1 - Method and apparatus for a combined casting-rolling installation - Google Patents

Abstract

The invention relates to a method and an apparatus for producing hot-rolled products in a combined casting-rolling installation.  The object of the invention is to provide a method and a combined casting-rolling installation with which the uninterrupted continuous casting process can be maintained not only when there is a planned interruption to production but also when there is an unplanned interruption to production, occurring for example in a heating zone, a finishing mill train, a cooling zone or a storage device.  This object is achieved by a method in which the following method steps are carried out to bridge an interruption in production in the part of the installation that is downstream of the cutting-up and delivering device (6): a) cutting off a strand portion (21) of the continuously produced preliminary material (3) by means of a first shears (9); b) raising the tail part of the strand portion (21) from the roller table (4) by means of a raising device (11); c) breaking up the preliminary material (3) passing the first shears (9) into pieces of scrap (19) by means of the first shears (9), delivering the pieces of scrap (19) and removing the strand portion (21) until the operational readiness of the combined casting-rolling installation is restored.

Description

The present invention relates to a method and an apparatus for producing hot-rolled products in a cast-rolling composite plant.

More specifically, the invention relates to a method of producing hot rolled products in a cast-roll compound plant wherein an endlessly-extruded precursor is uncut, i. transported as a strand, to a rolling mill, rolled there, then cooled, cut and stored.

Cast-rolling compound systems for implementing this method essentially comprise a casting installation, a roller table, a rolling plant suitable for direct use on cast products, a cooling section and a storage device (eg a flat product rewinder, a wire laying device or a long product outlet section) ,

In order to be able to maintain the continuous operation of the continuous casting plant in the case of planned production stoppages, such as, for example, during a roll change or during maintenance work, it is possible in accordance with WO 00/71272 A1 either a) the strand of continuously produced starting material is separated and the rolling speed is increased; or b) separating the strand and reducing the casting speed; or c) the strand is divided into strand sections, which are subsequently discharged.

For unplanned production interruptions, such as in a fault in the heating section, the cooling section or the storage device, or an emergency stop in the finishing train, this is from the WO 00/71272 A1 known method not suitable because a collision between the continuous produced starting material and the separated strand section can not be avoided. Thus, the continuous casting process must continue to be interrupted in the event of an unplanned production interruption.

The object of the invention is to provide a method and a casting-rolling composite system of the type mentioned, with which the continuous continuous casting process not only in a planned but also in an unplanned production interruption, which, for example, in a heating line, a finishing train, a cooling section or a storage device occurs, can be maintained.

1. a) Abschneiden eines Strangabschnitts des kontinuierlich produzierten Vormaterials mittels einer ersten Schere;
2. b) Anheben des Fußteils des Strangabschnitts vom Rollgang mittels einer Anhebevorrichtung;
3. c) Zerstückeln des die erste Schere passierenden Vormaterials in Schrottstücke mittels der ersten Schere, Ausfördern der Schrottstücke, Entfernen des Strangabschnitts bis zur Wiederherstellung der Betriebsbereitschaft der Gieß-Walz-Verbundanlage.

This object is achieved by a method in which the following method steps are carried out for bridging a production stoppage in a plant part which is downstream of the device for cutting and discharging:

1. a) cutting a strand section of the continuously produced starting material by means of a first pair of scissors;
2. b) lifting the foot part of the strand section from the roller table by means of a lifting device;
3. c) Dismembering the primary material passing through the first shears into scrap pieces by means of the first shears, discharging the scrap pieces, removing the strand section, and restoring the operational readiness of the cast-rolling composite plant.

The continuously produced by a continuous casting plant and possibly pre-rolled material is referred to as the starting material. The separated part of the strand of the continuously produced starting material is referred to in this document as a strand section. The pieces of primary material which are fragmented and discharged by the first pair of scissors are called scrap pieces. At the specified production interruptions they may preferably be unplanned interruptions, eg emergency stops, but also planned interruptions for conversion, repair or maintenance work, which occur in one of the device for cutting and discharging downstream plant part. The dismembering of the primary material and discharging the scrap pieces is maintained until either no more material passes the first pair of scissors or stops production interruption, ie. the operational readiness of the cast-rolling composite plant has been restored. Before resuming normal operation of the cast-rolling composite, ensure that the cut strand section is removed and the lifting device lowered again.

In an advantageous for the collision-free operation of the system expression of the method, the cutting of the strand portion of the continuously produced starting material by means of the first pair of scissors takes place simultaneously or immediately after the occurrence of production interruption. Truncation is considered to have taken place immediately after the stoppage of production, when the lifting of the lifting device was essentially initiated after a short period of time, including the signal transit times from a sensor to the controller and the controller to the lifting device, and the reaction time of the controller.

The lifting of the foot part of the strand section by means of the lifting device is advantageously carried out immediately after the cutting of the strand section and ensures that there can be no collision between the cut strand section and the continuously produced starting material.

Advantageously, the scrap pieces in a lowerable roller table, which is located downstream of the first pair of scissors, discharged and until the restoration of operational readiness the cast-rolling composite plant removed. It should be noted that the retractable roller table is raised again before resuming normal operation of the cast-rolling composite system. Of course, the scrap pieces can also be discharged by means of a transverse conveyor from the roller table in an external storage area.

In a particularly advantageous manner, the method according to the invention is carried out if, at the same time or after cutting off the strand section, the starting material is split by second scissors, which are upstream of the first scissors, onto precursor sections which are separated by a discharge device which extends between the second and the second section first scissors is located, be carried out. The thus-conveyed starting material sections have a certain length, for example 8 to 14 m, and are referred to as precursor sections and may be e.g. be subjected to a later processing in an external rolling mill. The breakdown of the primary material and the discharge of the precursor product sections are maintained until the operational readiness of the cast-rolling composite plant is restored.

The outfeed of Vorproduktabschnitten by means of the Ausfördervorrichtung is advantageously carried out by lifting the Vorproduktabschnitte from the roller table, a transport to a stacking device and lowering into a stacking device.

In order to facilitate the collision-free delivery of precursor sections, it is advantageous to accelerate the precursor sections prior to discharge in the delivery device by means of motor-driven rollers or drive rollers on the roller table. This creates a gap between the incoming primary material and the precursor section.

In a further advantageous embodiment, the process is carried out at large total thickness changes between the endless continuously cast starting material and the end product so that the starting material after its complete solidification in a single or multi-stand roughing without additional heating, i. with the casting heat of the continuous casting process, is pre-rolled. In this case, the continuously cast starting material is rolled in a continuous casting line downstream Vorwalzstraße, which in this embodiment, even large changes in thickness in the roughing mill, especially when using a so-called High-Reduction Mill, can be achieved without additional heating of the rolling stock.

A reduction in the transport speed of the continuously cast starting material at the same time or immediately after the occurrence of a production interruption, or the cutting of the strand section with the first pair of shears, can be advantageous for different reasons. On the one hand, this may be the case if commercial utilization of the scrap pieces or the precursor product sections is not to be expected. On the other hand, this may be the case when the second pair of scissors is designed as pendulum scissors, which may only work reliably at relatively low transport speeds, but would like to start as soon as possible with the discharge of precursor sections.

In a particularly advantageous manner, the reduction of the transport speed of the starting material is achieved by driving up one or more stands of the roughing mill.

Furthermore, the reduction of the transport speed of the semi-finished material can also be achieved by reducing the casting speed of the continuously operating continuous casting plant. This measure is particularly useful if the starting material is not pre-rolled and / or a commercial utilization of the starting material is not expected.

Even when starting the cast-rolled composite plant, the inventive method proves to be advantageous. For this purpose, a starter strand is introduced into the continuous casting plant, which is moved along with the cast strand. The Anfahrstrangkopf is separated with a part of the endless continuously cast starting material of one of the scissors (the first or second scissors) and removed in the field of Ausfördervorrichtung.

It is also advantageous that a wedge piece formed on the continuously cast starting material during start-up of the pre-rolling line is separated or dismembered by the second pair of scissors and removed in the area of the discharge device. A wedge piece is formed, for example, during the employment of the work rolls of the rough rolling mill on the operating roll thickness, or by a special driving style of the continuous casting plant.

Depending on the temperature and the transport speed of the starting material, the plant layout and the specific requirements of the end product (for example the structural properties), it may be advantageous to set the temperature of the uncut starting material to rolling temperature by means of a heating section before rolling in the finishing train.

In order to enable the most direct implementation of the method according to the invention, which solves the problem underlying the invention, it is advantageous that a device for cutting and discharging a first pair of scissors and downstream includes a lowerable roller table and a lifting device. With this embodiment of the device for cutting and conveying, it is possible to cut the starting material on scrap pieces and auszufördern from the plant. In a particularly compact embodiment The lifting device can be sunk in the lowerable roller table.

In a particularly advantageous manner, the means for cutting and discharging is carried out so that the first scissors upstream of a second pair of scissors and between the second and the first pair of scissors is a Ausfördervorrichtung. Thus, it is possible to divide the starting material on Vorproduktabschnitte, auszufördern from the plant and optionally supply a residual use.

With large overall thickness changes between the continuously cast starting material and the end product is advantageously between the continuous casting plant and the means for cutting and discharging a single or multi-stand roughing mill.

A heating section and, where appropriate, a descaling system is expediently located in front of a single-stand or multi-stand finishing train.

A foot of a cut strand section can then be particularly quickly and advantageously lifted from the roller table when the lifting device is designed as a hydraulically driven lifting beam.

In order to keep the cooling of the starting material as low as possible when passing through the device for cutting and discharging and thus to take as much casting heat from a continuous casting plant into a rolling train, it is advantageous to assign the Ausfördervorrichtung an enclosure.

In order to accelerate the transport of the primary material in the region of the first and / or the second pair of scissors and thereby achieve a time interval between successive Vorproduktabschnitten or scrap pieces, is It is advantageous that upstream and / or downstream of the first and / or the second pair of scissors are each motor-driven rollers or drive rollers.

It is also particularly advantageous to perform the first pair of scissors as drum shears and / or the second pair of scissors as pendulum scissors.

With regard to the system type of the heating section, it is advantageous to design the heating section as a tunnel heating section with induction heating.

• Fig. 1 eine schematische Darstellung einer Gieß-Walz-Verbundanlage für den vollkontinuierlichen Endlosbetrieb gemäß der Erfindung
• Fig. 2 und 3 schematische Darstellungen einer erfindungsgemäßen Einrichtung zum Zerteilen und Ausfördern
• Fig. 4 eine schematische Darstellung einer erfindungsgemäßen Ausfördervorrichtung

Further advantages and features of the present invention will become apparent from the following description of non-limiting embodiments, reference being made to the following figures, which show:

• Fig. 1 a schematic representation of a casting-rolling compound plant for fully continuous endless operation according to the invention
• FIGS. 2 and 3 schematic representations of a device according to the invention for cutting and Ausfördern
• Fig. 4 a schematic representation of a Ausfördervorrichtung invention

Fig. 1 shows a casting-rolling composite plant 1. In normal operation, a continuous casting plant 2 generates a continuously continuously cast starting material 3, which is transported by means of a roller table 4 to a roughing 5. After rough rolling in the rough rolling mill 5, the starting material 3 passes through uncut, ie as a strand, a means for cutting and conveying 6, before the temperature of the starting material is set in a heating section 12 to rolling temperature. After the treatment of the starting material in a descaling plant 13, which is upstream of a finishing train 14, the descaled starting material in the on or Rolled multi-stand finishing train 14. The finished rolled material is then cooled in a cooling section 15, cut by a pair of scissors 16 to a certain product length or a certain product weight and then wound up by means of a storage device 17 designed as a take-up device.

1. a) Abschneiden eines Strangabschnitts 21 des kontinuierlich produzierten Vormaterials 3 mittels der als Trommelschere ausgeführten ersten Schere 9. Das Abschneiden erfolgt gleichzeitig oder unmittelbar nach dem Auftreten der Produktionsunterbrechung.
2. b) Anheben des Fußteils des abgeschnittenen Strangabschnitts 21 vom Rollgang 4 im Bereich nach der ersten Schere 9 mittels der Anhebevorrichtung 11, welche als hydraulisch angetriebener Hebebalken ausgeführt ist. Dabei wird nach dem Abschneiden ausschließlich der Strangabschnitt 21 angehoben, sodass es zu keiner Kollision zwischen dem Strangabschnitt 21 und dem nachfolgenden Vormaterial 3 kommen kann. Der Hebebalken 11a der Anhebevorrichtung 11 ist in angehobener Position gezeichnet.
3. c) Zerstückeln des die erste Schere 9 passierenden Vormaterials 3 auf Schrottstücke 19 und Ausfördern der Schrottstücke 19 in den absenkbaren Rollgang 18. Je nach Anzahl der ausgeförderten Schrottstücke wird der absenkbare Rollgang von Hubelementen (als Hydraulik- oder Pneumatikzylinder oder elektrische Hubspindelantriebe ausgeführt) abgesenkt. Der absenkbare Rollgang 18 ist in abgesenkter Position gezeichnet. Vor Wiederaufnahme des Normalbetriebs der Gieß-Walz-Verbundanlage ist sicherzustellen, dass die Schrottstücke 19 vom absenkbaren Rollgang 18, beispielsweise mittels eines Krans oder ähnlicher Gerätschaften, entfernt werden und der Strangabschnitt 21 entfernt wird. Weiters muss die Anhebevorrichtung 11 abgesenkt und der absenkbare Rollgang 18 angehoben werden.

In Fig. 2 An embodiment according to the invention of the device for dividing and conveying 6, comprising a first scissors 9, a lowerable roller table 18 and a lifting device 11 is shown in more detail. After the occurrence of a planned or unplanned production interruption in a plant part, which is downstream of the device for cutting and discharging 6, the following process steps are carried out in the device for cutting and discharging 6:

1. a) cutting off a strand section 21 of the continuously produced primary material 3 by means of the first scissors 9 designed as a drum shears. The cutting takes place simultaneously or immediately after the production stoppage has occurred.
2. b) raising the foot part of the cut strand section 21 from the roller table 4 in the area after the first scissors 9 by means of the lifting device 11, which is designed as a hydraulically driven lifting beam. In this case, only the strand section 21 is lifted after cutting, so that there can be no collision between the strand section 21 and the subsequent semi-finished material 3. The lifting beam 11a of the lifting device 11 is drawn in the raised position.
3. Depending on the number of scrap pieces conveyed out, the lowerable roller table is lowered by lifting elements (designed as hydraulic or pneumatic cylinders or electric lifting spindle drives). The lowerable roller table 18 is drawn in lowered position. In front Resuming the normal operation of the cast-rolling composite is to ensure that the scrap pieces 19 are removed from the lowerable roller table 18, for example by means of a crane or similar equipment, and the strand section 21 is removed. Furthermore, the lifting device 11 must be lowered and the lowerable roller table 18 are raised.

In Fig. 3 FIG. 3 shows a further embodiment according to the invention of the means for dividing and conveying 6, comprising a second pair of scissors 7, a discharge device 8, a first pair of scissors 9, a lowerable roller table 18 and a lifting device 11. This is at the same time or after the under Fig. 2 described step a (cutting off the strand section 21), the starting material 3 of a second pair of scissors 7, which is the Ausfördervorrichtung 8 and designed as pendulum scissors, on precursor sections 10 of certain length, for example, pieces of 8 to 14 m in length, divided and accumulating Preproduct sections 10 conveyed out by means of a Ausfördervorrichtung 8. The work steps b and c (raising the strand section, dismembering and discharging scrap pieces) are as already under Fig. 2 described carried out. The transport speed of the preliminary material 3 is reduced simultaneously or immediately after the cutting of the strand section 21. This is done either by driving one or more stands of the roughing mill or by reducing the casting speed of the continuously operating continuous casting plant. At least individual rollers of the roller table before and / or after the first pair of scissors 7 and / or the second pair of scissors 9 are designed as motor-driven rollers or as so-called drive rollers 20. By means of these rollers, it is possible, on the one hand, to rapidly transport a precursor section 10 from the second scissors 7 to the discharge device 8 (creating a gap between adjacent incoming material 3 and the precursor section 10, thereby On the other hand, it is also possible to quickly transport the cut from the second pair of scissors 7 material to the first scissors 9 (the dismembering of scrap pieces). Before restarting the normal operation of the cast-rolling composite system, it is to be ensured that the scrap pieces 19 are removed from the lowered roller table, for example by means of a crane or similar equipment, and that the strand section 21 is likewise removed, for example by means of a crane 22. Furthermore, the lifting device 11 must be lowered and the lowerable roller table 18 raised again.

In Fig. 4 the discharge device 8 is shown in more detail. By means of a lifting cylinder 24 and a displacement cylinder 25, it is possible to lift a precursor section 10 with a transport platform 26 from a roller table, not shown, to convey to a stacking device 23 and store there. Here, the lifting cylinder 24 is connected via a pivot lever 27 to the transport platform 26 and primarily responsible for the lifting operation. The displacement cylinder 25 is also connected via a pivot lever 28 and a linkage with the transport platform 26 and primarily responsible for the displacement operation. The cyclic movement sequence of the transport platform 26 (solid lines show the starting position, dashed lines show the end position) and the transport path of the prefabricated section 10 transported therewith is illustrated in the movement diagram with arrows. The stacking device 23 comprises a storage platform, which is adjustable in height by means of a lifting element 29 (designed as a hydraulic, pneumatic cylinder or electric lifting spindle drive). This makes it possible to stack several Vorproduktabschnitte each other and thus very compact.

LIST OF REFERENCE NUMBERS

1

Casting and rolling plant

2

Continuous casting plant

3

Raw material

4

roller table

5

roughing

6

Device for cutting and conveying

7

Second pair of scissors

8th

extraction device

9

First pair of scissors

10

Vorproduktabschnitt

11

lifting device

11a

lifting beam

12

heating section

13

descaling

14

Finishing mill

15

cooling section

16

scissors

17

memory device

18

Lowerable roller table

19

scrap piece

20

capstan roller

21

strand section

22

crane

23

stacker

24

lifting cylinder

25

displacement cylinder

26

transport platform

27

Swivel lever lifting cylinder

28

Swivel lifting displacement cylinder

29

Lifting element stacking device

Claims (24)

1. Process for producing hot-rolled products in a combined casting and rolling installation (1), wherein a billet of a continuously continuously cast precursor material (3) passes through a cutting-up and discharging device (6) at a transportation speed in uncut form after it has fully solidified, is then rolled in a finishing rolling mill train (14), then cooled, cut up and stored, characterized in that an interruption to production in a part of the installation downstream from the cutting-up and discharging device (6) is bridged by carrying out the following process steps:

   a) a billet portion (21) of the continuously produced precursor material (3) is cut off by means of first shears (9);

   b) the tail part of the billet portion (21) is raised from the roller table (4) by means of a raising apparatus (11);

   c) the precursor material (3) passing the first shears (9) is broken up into pieces of scrap (19) by means of the first shears, the pieces of scrap (19) are discharged and the billet portion (21) is removed until the operational readiness of the combined casting and rolling installation (1) is restored.
2. Process according to Claim 1, characterized in that the billet portion (21) of the continuously produced precursor material (3) is cut off by means of the first shears (9) at the same time as or immediately after production is interrupted.
3. Process according to either of the preceding claims, characterized in that the tail part of the billet portion (21) is raised by means of the raising apparatus (11) immediately after the billet portion (21) is cut off.
4. Process according to one of the preceding claims, characterized in that the pieces of scrap (19) are discharged into a lowerable roller table (18) and are removed until the operational readiness of the combined casting and rolling installation (1) is restored.
5. Process according to one of the preceding claims, characterized in that the precursor material (3) is cut up into precursor product portions (10) by second shears (7), which are situated upstream from the first shears (9), at the same time as or after the billet portion (21) is cut off, and these precursor product portions are discharged by means of a discharging apparatus (8) situated between the second shears (7) and the first shears (9).
6. Process according to Claim 5, characterized in that the precursor product portions (10) are discharged by means of the discharging apparatus (8) by being raised from a roller table (4), transported to a stacking apparatus (23) and lowered.
7. Process according to either of Claims 5 and 6, characterized in that the precursor product portions (10), before they are discharged in the discharging apparatus (8), are accelerated on the roller table (4) by means of motor-driven rollers or driving rollers (20).
8. Process according to one of the preceding claims, characterized in that the continuously continuously cast precursor material (3) is rough-rolled in a single-stand or multi-stand rough-rolling mill train (5) without additional heating, i.e. with the casting heat from the continuous casting process, after it has fully solidified.
9. Process according to one of the preceding claims, characterized in that the transportation speed of the continuously cast precursor material (3) is reduced at the same time as or immediately after production is interrupted or the billet portion (21) is cut off with the first shears (9).
10. Process according to Claim 8 or 9, characterized in that the transportation speed of the precursor material (3) is reduced by the opening up of one or more stands of the rough-rolling mill train (5).
11. Process according to Claim 9, characterized in that the transportation speed of the precursor material (3) is reduced by a reduction in the casting speed of a continuously operating continuous casting installation (2).
12. Process according to one of Claims 1 to 11, characterized in that a start-up billet is introduced into the continuous casting installation (2) during start-up of the combined casting and rolling installation (1), said start-up billet is moved concomitantly with the integrally cast billet, and the head of the start-up billet together with part of the continuously continuously cast precursor material (3) is severed by one of the shears (7, 9) and removed in the region of the discharging apparatus (8).
13. Process according to one of Claims 8 to 12, characterized in that a wedge piece produced during start-up of the rough-rolling mill train (5) on the continuously cast precursor material (3) is severed or broken up into pieces by the second shears (7) and removed in the region of the discharging apparatus (8).
14. Process according to one of the preceding claims, characterized in that the temperature of the uncut precursor material (3) is set to rolling temperature by means of a heating section (12) before rolling in the finishing rolling mill train (14).
15. Combined casting and rolling installation (1) for producing hot-rolled products from a continuously continuously cast precursor material (3), said installation comprising at least one continuous casting installation (2), a cutting-up and discharging device (6), a single-stand or multi-stand finishing rolling mill train (14), a cooling section (15) and a storage device (17), characterized in that the cutting-up and discharging device (6) comprises

    - first shears (9) for cutting off the precursor material (3) and, downstream therefrom,

    - a lowerable roller table (18) for discharging and

    - a raising apparatus (11) for raising a tail part of a billet portion (21) cut off from the precursor material (3).
16. Installation according to Claim 15, characterized in that second shears (7) are situated upstream from the first shears (9) and a discharging apparatus (8) is situated between the second shears (7) and the first shears (9).
17. Installation according to Claim 15 or 16, characterized in that a single-stand or multi-stand rough-rolling mill train (5) is situated between the continuous casting installation (2) and the cutting-up and discharging device (6).
18. Installation according to one of Claims 15 to 17, characterized in that a heating section (12) and a de-scaling installation (13), which possibly adjoins the latter, are situated upstream from the single-stand or multi-stand finishing rolling mill train (14).
19. Installation according to one of Claims 15 to 18, characterized in that the raising apparatus (11) is designed as a hydraulically driven jib (11a).
20. Installation according to one of Claims 15 to 19, characterized in that a housing is assigned to the discharging apparatus (8).
21. Installation according to one of Claims 15 to 20, characterized in that motor-driven rollers or driving rollers (20) are respectively situated upstream and/or downstream from the first shears (9) and/or the second shears (7).
22. Installation according to one of Claims 15 to 21, characterized in that the first shears (9) are designed as drum shears.
23. Installation according to one of Claims 16 to 22, characterized in that the second shears (7) are designed as pendulum shears.
24. Installation according to one of Claims 15 to 23, characterized in that the heating section (12) is designed as a tunnel heating section with induction heating.

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