EP1337365B1 - Strand guide of a continuous casting installation comprising a device for secondary cooling - Google Patents

Description

The invention relates to a strand guide of a continuous caster, comprising below a mold for guiding elements equipped with guide rollers for support and guiding a cast strand, as well as one referred to as secondary cooling Device for supplying the cast strand with coolant in different zones Cooling intensity, usually with water, by means of against the guide rollers and / or the cast strand of directed spray nozzles.

An essential task of the above-mentioned strand guidance is to act on it of the cast strand in the area between the support elements to continuously withdraw heat from a coolant and thereby freeze of the still liquid core of the cast strand. State of the art is the device, which is called secondary cooling, through a pipe system build with which coolant is distributed in a predetermined manner and is sprayed onto the slab.

Strand guides with integrated means for continuous cooling of the cast strand are known. Document EP 0 642 857 A2 describes a continuous caster, whose strand guide segments with the variably adjustable Width of the strand distributed, in the strand running direction, if necessary in Cooling zones divided spray elements connected to cross-distributor pipes, especially battens are provided. The going beyond the minimum strand width arranged, outer spray battens are dependent on the respective String width, can be switched on or off. For this purpose, are concentric at both ends arranged inside the transverse distribution pipes arranged on closed their free ends and provided there with an outer square are screwed to a web.

When casting a strand of liquid metal with the maximum strand width are the inflow openings in the cross distribution pipes for everyone Spray battens opened. Now a narrower strand format should be poured in and out lateral overmolding of the strand can be prevented, only need the Inner tubes to be twisted about their longitudinal axis. This can be done using a Socket wrench happen from the outside of the cooling chamber to the outside square the inner tube is attached. Because of the connection of both Both inner tubes of each cross distributor via a coupling tube Inner tubes twisted at the same time, which has the consequence that of the addable or removable Spray battens in pairs, first the outer, then the middle and then the inner spray battens are closed.

U.S. Patent 4,220,192 describes a combination of a bearing arrangement for rollers with a spray system for coolant to be arranged at the floor outlet a continuous casting mold with at least one pair on horizontal axes arranged rollers which grip the strand emerging from the mold and lead. The bearing arrangement is designed with an elongated passage, in which cooling water flows. The water flows across a multitude directional passages that are formed in the bearing assembly and with nozzle ends are provided, which are aligned so that cooling water above and below the rolls and flows against the adjacent surface of the cast strand and this cools. The splash water also cools the inside of the bearing assembly Flow through the passages, thus preventing deformation and warping the aligned rollers and nozzles.

The document EP 0 028 686 B1 describes an adjustment device for along so-called extending the surface of a strand of a continuous caster Spray bars as supports for spray pipes directed at the surfaces to be applied the surfaces with a cooling medium, e.g. B. water. To change the distance of the spray bars relative to the strand are in adjustment changing widths of strand surfaces, the spray bars at least in zones adjustable parallel to itself using a handlebar system.

For the purpose of adjustment, they are all arranged on the four sides of the strand and spray bars extending along the surface of the strand worn at least two steering levers, such that the spray bars at Move the change in distance in the direction of the longitudinal axis of the strand. Here are the Steering lever of the side spray bar, which is assigned to a strand surface are, the center of which shifts with changing width of the strand surface, in Inclined swiveling. These form with the respective one perpendicular to the assigned one Strand surface through the spray plane running through the spray tubes an acute angle α, such that with the change in distance of the spray bar a transverse displacement of the spray bars including spray pipes relative to the longitudinal axis of the strand accompanied.

Document DE 30 39 443 A1 discloses a spray nozzle arrangement in the Secondary cooling of a continuous steel caster, with at least two across spray nozzles arranged side by side to adjust the distance from the strand surface and their mutual distance their leads are attached to holders that are articulated on adjusting levers and are straightforward. Two fixed, opposite Adjusting levers are provided with a push rod in the manner of an anti-parallel crank opposite movement transmission and connected to the adjustment levers hinged holders are guided parallel to the strand surface.

Document DE 197 02 718 C1 discloses a method and an apparatus for cooling medium control in a continuous caster. To increase or decrease of the cooling medium amount are the nozzles arranged on spray battens a cooling zone can be switched on and off. There are several within a zone Spray battens selectively selected and at least two spray groups summarized. If the system pressure for the The individual groups are alternately in a fixed cooling medium Time interval can be switched on and off. A device for performing the method includes below the continuous casting mold in a provided with guide rollers Cooling section parallel to the guide rollers at a distance from each other arranged spray slats, each having a spray nozzle at the open end. These are connected to a distributor pipe, and in the withdrawal direction of the Stranges are several selectively selected spray battens within one Zone combined into a spray group. In the fork of the individual A control valve is arranged for groups of spray pipes carrying spray bars. The control valve is time-controllable and at a system pressure of the Cooling medium designed responsive.

Starting from the aforementioned prior art, the object of the invention an uncomplicated basis for the continuous routing of a continuous caster and appropriate combination of the support and management function with an effective one Cooling of the strand in a particularly compact structure of the guide elements to realize.

To solve the problem is the continuous flow of a continuous caster proposed in the preamble of claim 1 with the invention, that the secondary cooling is designed with cooling boxes, which preferably along the strand guide are divided into separate chambers, the cooling boxes are integrated into the structure of the guide elements.

By designing the secondary cooling with cooling boxes and dividing them up in zones with different cooling intensity in separate chambers the guide elements achieve a compact and uncomplicated building structure, the ideal conditions for the different tasks, namely Strand guidance and strand cooling, results.

Further refinements of the invention are in accordance with the subclaims intended.

Figur 1

eine Ansicht einer Kokille beim Gießen eines Stranges und unter dieser angeordnete Führungselemente, im Schnitt;

Figur 2

ein Führungselement mit Kühlkästen im Schnitt einer horizontalen Ebene II-II in Fig. 1;

Figur 3

eine erste Ausführung eines Strangführungselementes, im Schnitt;

Figur 4

eine alternative Bauart eines Strangführungselementes.

Figur 5

eine andere Ausführung eines Führungselementes mit Kühlkästen im Schnitt einer horizontalen Ebene II-II in Figur 1;

Figur 6

eine andere Ausführung eines Führungselementes gem. Figur 3, im Schnitt.

Details, features and advantages of the invention result from the following explanation of some exemplary embodiments schematically illustrated in the drawings. Show it:

Figure 1

a view of a mold when casting a strand and arranged below this guide elements, in section;

Figure 2

a guide element with cooling boxes in the section of a horizontal plane II-II in Fig. 1;

Figure 3

a first embodiment of a strand guide element, in section;

Figure 4

an alternative design of a strand guide element.

Figure 5

another embodiment of a guide element with cooling boxes in the section of a horizontal plane II-II in Figure 1;

Figure 6

another version of a guide element acc. Figure 3, in section.

The section of a continuous caster shown in Fig. 1 comprises the pouring tube 15 from a tundish, not shown, into a continuous casting mold 1 vertical flow direction. Under the mold 1 are two guide elements as an example 3, 3 ', each with four pairs of guide rollers 2 Is provided. The cast strand 4 is between the guide roller pairs 2 supported and guided.

Corresponding to the sectional plane II-II shown in FIG. 1, FIG. 2 shows below the mold 1 is equipped with guide rollers 2, 2 'guide element 3 for Supporting and guiding the cast strand 4. The strand guiding element 3 is in on known manner for the frictional application of the guide rollers 2, 2 ' formed with a fixed side 17 and a loose side 17 ', which is why not here the known construction will be discussed further. It owns as essential piece of equipment a device referred to as secondary cooling to apply coolant 5 to the cast strand 4, as a rule Water.

Deviating from known embodiments, the secondary cooling is after the essential feature of the invention with crossbeams as cooling boxes 6, 6 'formed along the strand guide according to their predetermined Classification with zones of different cooling intensity in separate chambers 7, 7 'are divided.

In this case, as the feed medium for the cooling medium facing the cast strand 4 Side of the cooling boxes 6, 6 'arranged with nozzles 9 nozzle tubes 10.

The nozzle tubes 10 with the connection points of the cooling boxes are very advantageous 6, 6 'can be connected or disconnected from them by quick disconnect couplings 11. there can be made use of the further measure that the Nozzles 9 with the nozzle tubes 10 by quick disconnect couplings (not shown) are connectable or separable from them.

Furthermore, the water supply lines 12 can each be individually equipped with shut-off devices 13 be equipped if this is for the design of a changing production program appears necessary. And finally the water supply lines 12 are each connected to a water supply pipe 14, which is connected to a central water supply 19. On in this way the individual chambers 7, 7 'of the cooling boxes 6, 6' depending on Width of the cast strand can be switched on and off. This is the one with coolers 6, 6 'trained secondary cooling in adaptation to the respective Geometry of a cast strand can be flexibly adjusted.

3 is the above-described structural structure of a guide element 3 for supporting and guiding a cast strand 4 in the direction of view thereof Narrow side shown in longitudinal section. The recognizable building structure includes an outer frame corresponding to the broad side of the cast strand 4th parallel trusses 20. The illustration shows the extremely advantageous Integration of the cooling boxes 6 in connection with the cross members 16 and the attached to these broadside cross members 20. The guide element 3 has in a known arrangement narrow side parts with the fixed side part 17 and Loss side part 17 'in a known assignment with means not shown for merging or unfolding in the open position shown 3. In this position, cooling water 5 can carry individual Chambers 7, 7 'can be formed continuously from top to bottom, wherein then adjacent chambers, for example in the area of a narrow cast strand 4 can be switched off zone by zone, as shown in FIG. 2.

3 shows the assignment of nozzle tubes 10 in a clear manner Nozzles 9 to the guide rollers 2 and to the cast strand 4 3 shows the particularly compact and expedient integration of the cooling boxes 6 in the structure of a guide element 3 can be seen.

A somewhat different design of a guide element 3 is shown in FIG. 4 the cooling boxes with the help of fasteners 8, 8 'on the structure of the Guide elements 3 attached from the outside.

The illustration shows the fixed side part 17 and the loose part 17 'with the outside arranged cooling boxes 6, 6 '. As previously in FIG. 2 shown, also with side cooling chamber parts 7 from the middle cooling chamber part 7 'can be switched off.

The illustration shows the basic concept of nozzle pipes 10 with attached nozzles 9 when spraying the guide rollers 2, 2 'with water spray jets. The broadside trusses are shown in FIG. 3 with the Reference number 20 marked.

The building structure according to FIG. 4 is suitable, for example, for retrofitting an existing one Guide element with a particularly intensive water cooling system for cast strands with variable thickness.

When dividing the cooling boxes 6, 6 'in the width direction of the cast strand 4 in separate chambers 7, 7 'according to different requirements for the Cooling intensity, the width of the middle chamber 7 'can be correspondingly larger be designed in comparison to the side chambers.

It is also expedient that the width of the separate Chambers 7, 7 'at least the respective outer chambers 7 via separate water supply lines 12, 12 ', as can be seen, for example, from FIG. 2, with integrated Shut-off devices 13 each connected to a pressure water supply pipe 14 are. The bearings for the guide rollers 2 are with the cross members 16 connected. This results in a stable and torsion-resistant design.

FIG. 5 shows a somewhat different design of FIG. 2.

In this case, the cooling boxes 6, 6 ', 6 "on each side 17 and 17' are in pairs the water supply pipes 14, 14 'can be connected, and the middle cooling boxes 6, 6' arranged to be connected to a central water supply 19, 19 '.

Loose part 17 'and fixed part 17 of the guide element 3 are by (not shown) Power means in mutual distance according to the thickness of a strand 4 adjustable against each other.

The cooling boxes 6, 6 'are in the central area through an opening in each central area Crossbar 18, 18 'in communication with each other and on the central water supply 19, 19 'connected.

Figure 6 shows a construction of the guide element 3 similar to Figure 3, however with simplified equipment and arrangement of the cross members 16 for support the walls 22, 22 'of the cooling boxes 6. These are to the central water supply 19, 19 'connected via throttle bodies 21, 21'.

LIST OF REFERENCE NUMBERS

1

mold

2, 2 '

guide rollers

3, 3 '

guide element

4, 4 '

Cast strand / strand shell

5

Coolant, coolant

6, 6 '

cooling box

7, 7 '

chamber

8, 8 '

fastener

9

jet

10

nozzle tubes

11

Quick disconnect coupling

12

Water supply line

13

shutoff

14

Water supply pipe

15

A submerged nozzle

16

crossbeams

17

fixed side

17 '

loose part

18

middle crossbar

19

Central water supply

20

Traverse broadside

21

throttle member

22

Cooling box walls

Claims (4)

1. A billet guide of a continuous casting installation, with guide elements (3) that are equipped, in particular, with guide rollers (2, 2') and arranged underneath a continuous casting mould (1), wherein said guide elements serve for supporting and guiding a billet (4) being cast, and with a device that is referred to as a secondary cooling device and serves for acting upon the billet (4) being cast with a cooling medium, usually water, in zones of different cooling intensity by means of spray nozzles (5) that are directed against the guide rollers (2, 2') and/or the billet (4) being cast, characterized in that the secondary cooling device is realized with cooling boxes (6, 6') that are divided into separate chambers (7, 7'), preferably along the billet guide, wherein the cooling boxes (6, 6') are integrated into the structure of the guide elements (3).
2. The billet guide according to Claim 1, characterized in that the delivery means for the cooling medium are realized in the form of blast pipes (10) that are equipped with nozzles (9) on the side of the cooling boxes (6, 6) that faces the billet (4) being cast.
3. The billet guide according to Claim 1 or 2, characterized in that, if the cooling boxes (6) are divided into separate chambers (7) in the latitudinal direction of the billet (4) in accordance with different cooling intensity requirements, the greatest width is assigned to the central chamber (7').
4. The billet guide according to at least one of Claims 1-3, characterized in that, in a latitudinal division into separate chambers (7, 7'), at least the respective outer chambers (7) are connected to a pressure water supply pipe (14) via separate water supply lines (12, 12') with integrated shut-off elements (13).

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