EP2663412B1 - Equipment and method for producing hot-rolled strips - Google Patents

Description

The invention relates to a plant and a method for producing hot strip, wherein a casting machine for producing at least one casting strand, a separator for separating slabs from the casting strand, a transport system with a switch means for selectively transporting the slabs from the casting machine either in a rolling train or to a special treatment device. The rolling train is used to produce the hot strip from the slabs having a width smaller than a roll width threshold.

From the EP 0662 358 A1 is a generic system known.

A production planning method for increasing the throughput in the production of hot strip is the EP 1 363 750 known. In this method, the rolling mill is served, on the one hand, by a two-strand caster producing thin slabs and, on the other, by slabs from a warehouse. The slabs for the warehouse are produced by a twin caster, which pours thick slabs. These thick slabs are then fed via a slab feed device via a reheating furnace to a downstream roughing mill and rolled to Vorbändem, which are supplied in the form of coils of the rolling mill. Although the coil feeder bypasses unplanned downtime of the caster, however A huge amount of energy is needed to heat the coils back to rolling temperature.

A casting and rolling plant, which also combines continuous casting and rolling of slabs, is used in the DE 693 16 703 described. In particular, the document describes a method for producing wound strip, sheet in wound form or discrete sheet metal plates. The caster is operated in a single-strand casting process and produces slabs of various widths which are either placed directly in an oven to be fed to the mill train or stored in a slab collection area. The distinguishing criterion of whether the slabs are fed from the warehouse or directly from the casting machine to the rolling line depends on the production capacity of the casting machine. The slabs from the warehouse are used during production breaks of the casting machine for utilization of the connected rolling mill.

A disadvantage of the known casting rolling, however, is that the maximum width of the casting strands is matched to the width of the rolling mills, the casting mill is inflexible in production and thus no increase in capacity can be achieved. Another disadvantage is that an energy-saving driving is hardly possible by a plurality of furnaces in the plant for reheating the cold slabs or coils.

The object of the invention is to develop a known system and a known method for producing hot strip, to increase the production capacity and increase the flexibility already in the production to achieve the cast strand and offer an energy-saving configuration of the plant, which thus produces cost-effectively.

This object is solved by the subject matter of claim 1. This object is characterized in that the casting machine is designed as a twin-casting machine for producing the at least one casting strand having a width which is smaller or larger than the roll width threshold value and in that a first control device for the switch means is provided for branching the slabs having a width smaller than the rolling width threshold in the rolling line and for branching the slabs having a width greater than the rolling width threshold for the special treatment device.

The description of the invention is based on the following terms:

Roll width threshold:

The width of the slabs to be rolled is predetermined or limited by the width of the rolling train, in particular the width of the finishing train. The roll width threshold corresponds to the maximum width of the hot strip that can be processed in the finishing train.

Special treatment facility:

The slabs, the width of which is greater than the rolling width threshold, are not transferred to the connected mill train, but to a special treatment facility. This special treatment device can be an external slab stock, a special rolling mill for slabs of this width o.ä. be.

That according to claim 1, the casting machine is designed as a twin-casting machine, offers the advantage that not only in the single-strand process can be produced, but also in the two-strand process, the twin casting process. This application of the twin-casting machine offers the advantage of achieving increased flexibility in slab production, both in width and in speed. The subsequent switch device, which is provided for branching the slabs with a width smaller than the roll width threshold in the line of the rolling train, offers the advantage that the slabs can be fed without significant temperature losses directly to the rolling line or that the slabs with a width greater as the roll width threshold for the special treatment device can be diverted. This results in an increased flexibility in slab production. The productivity of the rolling mill is still fully guaranteed since the rolling mill is served from a first stock with slabs if the supply of slabs from the twin-casting machine is insufficient.

Characterized in that according to a first embodiment, the twin casting machine is arranged offset to the line of the rolling train and a transport system with a first feeder, for example, a Querverfahreinrichtung is provided, in this way, all slabs produced with a width smaller than the roll width threshold directly the rolling train be fed and all slabs with a width greater than the roll width threshold continue to be moved into the special treatment facility. Due to the first feeding device of the transport system, the slabs from the twin casting machine immediately enter a holding furnace and only have to be heated to rolling temperature in an energy-saving manner.

Advantageously, a holding furnace for holding the slabs having a width smaller than the rolling width threshold is designed such that the slabs are heated to rolling temperature with little energy. The design of the oven not only refers to the heating performance, but also to a short structural design of the holding furnace.

• eine Entzunderungseinrichtung
• eine Stauchungseinrichtung
• ein Reversierwalzgerüst
• eine Fördereinrichtung vor und / oder hinter dem Reversierwalzgerüst;
• eine Fertigwalzstraße

Advantageously, the rolling train at least one of the following components, preferably in the direction of passage of the slabs seen in the order mentioned:

• a descaling device
• a compression device
• a reversing roll stand
• a conveyor before and / or behind the Reversierwalzgerüst;
• a finishing train

By a local arrangement of the rolling train to the casting machine transport routes are avoided and thus prevents cooling of the slabs, resulting in energy savings.

Advantageously, the transport system further comprises a second feeder for slabs having a width smaller than the roll width threshold from a first store in the rolling line, so that in a production of slabs with a width greater than the roll width threshold through the twin casting machine, the downstream rolling mill still full remains busy. Of course, this also applies to production breaks of the twin casting machine.

Advantageously, the second feeding device is formed with a second control device, which enables the feeding of the slabs from the first bearing into the rolling train to be enabled when the rolling train alone is not loaded with slabs from the twin casting machine. This is true, for example, when the twin caster produces slabs that are wider than the roll width threshold. For this it is advantageous that the rolling mill can produce decoupled from the twin casting machine.

Advantageously, the casting machine for a special treatment device, which is designed either as a second bearing or as a special processing line, including a rolling mill, for processing the slabs having a width greater than the roll width threshold. This results in a great flexibility in the slab production and a better utilization of the twin casting machine.

The above object is further achieved by the method claimed in the independent method claim 8.

The advantages of this procedural solution correspond to the advantages mentioned above with respect to the device. Further advantageous embodiments of the method and the apparatus of the invention are specified in the subclaims.

Figur 1

die erfindungsgemäße Anlage

zeigt.The description is a total of a figure attached, wherein

FIG. 1

the inventive system

shows.

The system according to the invention and the method according to the invention are described in detail below with reference to the figure.

FIG. 1 shows a plant 100 for producing hot strip 260. The main components of the plant 100 are a twin casting machine 110, a connected rolling train 210-250, a holding furnace 200, a special treatment device 400, a first bearing 300 and a heating furnace 310. Die Twin Caster 110 is located near rolling line 210-250 and produces casting strands 120 in the twin casting process or in the single strand process. The casting strands 120 are separated from a separating device 125 to slabs 130 and then fed by a switch device 140, which is controlled by a first control device 150, via the holding furnace 200 of the rolling train 210-250 or the special treatment device 400. The twin casting machine 110 is preferably designed as a sheet system, for example with a casting radius of 4.5 to 7.0 m.

If the twin casting machine 110 produces pouring strands 120 in the single or twin casting process that have a width smaller than the width of the rolling width threshold value, the slabs 130 subsequently separated from the separating device 125 can be set by the transport system with a corresponding setting of the first control device 150 Turnout device 140 via a first feeder 170, for example, a cross-conveyor, are fed through the holding furnace 200 directly to the rolling train 210-250. After being heated to the rolling temperature in the holding furnace 200, the slabs 130 are descaled by a descaling apparatus 210 and fed to a reversing roll stand 230 and at least one conveyor 240 by a swaging device 220, which is optionally inserted into a finishing train 250 for rolling into hot strip 260. The subsequent winding of the hot strip 260 from a coiler to coils 270 is shown here only schematically at the end of the rolling train 210-250.

The twin-casting machine 110 can pour in the single-strand process a maximum width of the casting strands 120 of preferably 3600 mm. This maximum Width of the produced casting strands 120 and the slabs 130 subsequently severed by the severing means 125 is above the maximum width of the hot strips 260 to be produced. Because the rolling train 210-250 can only process slabs 130 having a width smaller than a roll width threshold, for example 2200 mm, slabs 130 having a width greater than the roll width threshold are diverted from the switch 140 to the special treatment device 400.

Specifically, while twin casting machine 110 is in the single-strand process producing slabs 130 having a width greater than the roll width threshold, cold slabs 130 may be removed from first bearing 300 by means of a second feeder 180 via a heating furnace 310, such as a walking beam furnace or puncture Furnace is formed, are fed into the rolling train 210-250. The slabs 130 from the first bearing 300 have a width that is less than or equal to the roll width threshold. The heating furnace 310 is designed for slabs 130 of these widths and preferably heats the slabs 130 to a temperature for hot rolling of 1100 ° C to 1250 ° C. After being heated to rolling temperature, the slabs 130 are processed from the rolling train 210-250 to hot strip 260.

While the mill train from the first bearing 300 produces hot strip 260 from the slabs 130, the twin-casting machine 110 preferably operates in the so-called "slab production" mode. That is, the twin caster 110 pours casting cords 120 having a width greater than the rolling width threshold of the rolling mill, but preferably less than or equal to 3600 mm, separated from slabs 130 - from the switch 140, controlled by the first controller 150, to the special treatment device 400 brought / branched off. The "slab production" slabs 130 can not be rolled from the connected mill 210-250 due to their too large width.

In the claimed system concept, the flexibility of the entire system 100 is increased and the productivity of the mill 210-250 remains fully guaranteed. By feeding the slabs 130 from the first bearing 300 and then further processing this slab in the rolling line 210-250 while the twin-casting machine 110 is operating in the "plate-making" mode, production amounts of 5.0 million tons per year can be represented.

On the other hand, if the twin casting machine 110 operates in the twin casting process, two parallel casting strands 120 each having a width of preferably 1750 mm and, for example, a thickness of 100 mm, corresponding to a web width of the twin casting machine of 100 mm, are cast. Any uneven temperatures of the slab narrow sides / edges are homogenized by the holding furnace 200, which is preferably designed as Hubbalkenofen, before use in the rolling train 210-250. The slabs 130 from the twin-casting process have a slab width that is smaller than the roll width threshold. Due to the close proximity arrangement of twin casting machine 110 and holding furnace 200, the slabs 130 are fed to the cold room 210-250 without cooling to room temperature and the temperature losses are reduced to a technological minimum. This also applies to slabs 130 from the single-strand process, which have a width smaller than the roll width threshold and are rolled from the connected rolling train to hot strip 260.

The twin casting machine 110 according to the invention produces casting strands 120 with a thickness of preferably 100-170 mm. The generated slab thickness is selected so that the roughing to the required intermediate thickness for the finish rolling with a minimum number of stitches in the Reversierwalzgerüst 230 is possible. Particularly preferred is a slab thickness of 150 mm is provided. Between the roughing passes, the intermediate belt is moved in the conveyor 240, which is preferably designed as a roller table, actively heated roller table, roller hearth furnace or tunnel kiln.

LIST OF REFERENCE NUMBERS

100

investment

110

Zwillingsgießmaschine

120

cast strand

125

separator

130

slab

140

soft furnishings

150

first control device for switch device

170

first feeder, preferably cross-conveyor

180

second supply device

185

second control device

200

Holding furnace

210

descaling

220

Compression device

230

reversing

240

Conveyor

250

Finishing mill

260

hot strip

270

coil

300

first camp

310

heating furnace

400

Special treatment facility

Claims (11)

1. Plant (100) for producing hot strip (260), comprising:

   a double casting machine for producing at least one cast strip (120);

   a separating device (125) for separating off slabs (130) from the cast strip (120);

   a rolling train (210-250) for producing the hot strip (26) from the slabs (130) with a width smaller than a rolling width threshold value; and

   a transport system with a switch device (140), which is controlled by a control device, for selectable transporting of the slabs (130) from the double casting machine either to the rolling train or to a special treatment device (400); and

   a double casting machine (110) which is constructed for producing the at least one cast strip (120) with a width which is smaller or larger than the rolling width threshold value;

   characterised in that

   the control device (150) for the switch device is provided for branching off the slabs (130) with a width smaller than the rolling width threshold value to the rolling train and for branching off the slabs (130) with a width greater than the rolling width threshold value for the special treatment device (400).
2. Plant (100) according to claim 1, characterised in that the double casting machine (110) is arranged to be offset with respect to the line of the rolling train; and that the transport system comprises a first feed device (170), for example a transverse movement device, for the slabs (130) having a width smaller than the rolling width threshold value, for feeding the slabs from the double casting machine (110) into the line of the rolling train.
3. Plant (100) according to any one of the preceding claims, characterised by a heat retention furnace (200) for keeping the slabs (130) hot, the furnace having a width smaller than the rolling width threshold value, during transport thereof from the double casting machine (110) into the line of the rolling train.
4. Plant (100) according to any one of the preceding claims, characterised in that the rolling train comprises at least individual ones of the following components:

   - a descaling device (210);

   - an upsetting device (220);

   - a reversing roll stand (230);

   - a conveying device (240) in front of and/or behind the reversing roll stand (230);

   - a finishing rolling train (250) for rolling the slabs (130) with a width which is smaller than the rolling width threshold value.
5. Plant (100) according to any one of the preceding claims, characterised in that the transport system comprises a second feed device (180) for slabs (130) with a width smaller than the rolling width threshold value from a first store (300) to the rolling train; and a heating furnace (310) is provided, for heating the slabs (130) from the first store (300) to a suitable rolling temperature for rolling of the slabs (130) in the rolling train.
6. Plant (100) according to claim 5, characterised in that a second control device (185) is provided for the second feed device (180) and so constructed as to enable feed of the slabs (130) from the first store (300) into the rolling train when the rolling train is not loaded up solely with slabs (130) from the double casting machine (110).
7. Plant (100) according to any one of the preceding claims, characterised in that the special treatment device (400) is constructed either as a second store or as a special processing train, inclusive of a rolling mill, for processing the slabs (130) with a width greater than the rolling width threshold value.
8. Method of operating a plant (100) for producing hot strip (260), comprising the following steps:

   - producing at least one cast strip (120);

   - separating off slabs (130) from the cast strip (120);

   - transporting the slabs (130) either for rolling in a rolling train (210-250) or for special treatment;

   - rolling the slabs (130) with a width smaller than a rolling width threshold value to form hot strip (260); and

   characterised by
   producing the at least one cast strip (120) on a double casting machine (110) with a width greater or smaller than the rolling width threshold value;
   branching off the slabs (130) with a width smaller than the predetermined rolling width threshold value for rolling in the rolling train; and
   branching off the slabs (130) with a width greater than the predetermined rolling width threshold value for the special treatment.
9. Method according to claim 8, characterised in that the slabs (130), the width of which is smaller than the rolling width threshold value, are heated to rolling temperature in a heat retention furnace (200) before feed into the rolling train.
10. Method according to claim 8, characterised in that during production pauses of the double casting plant (110) the rolling train is served from a first store (300) with slabs (130) with a width smaller than the predetermined rolling width threshold value.
11. Method according to claim 10, characterised in that the slabs (130) from the first store (300) are heated to rolling temperature before rolling.

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