WO2010006773A1

WO2010006773A1 - Electromagnetic braking device on continuous casting molds

Info

Publication number: WO2010006773A1
Application number: PCT/EP2009/005129
Authority: WO
Inventors: Norbert Vogl; Jörn HOFFMEISTER; Axel Weyer
Original assignee: Sms Siemag Ag
Priority date: 2008-07-15
Filing date: 2009-07-15
Publication date: 2010-01-21
Also published as: KR20130075785A; JP5236806B2; RU2011105386A; CN102099136B; CA2730616A1; DE102009029889A1; CN102099136A; JP2011527942A; EP2326441B1; RU2468886C2; EP2326441A1; US20110162817A1; KR20110025992A

Abstract

To bring about a direct effect on the fluid streams exiting the mould dip tube (2) of moulds in continuous casting moulds (1) of a continuous casting plant for casting liquid metals, in particular liquid steel materials for producing slab and thin slab products with format widths of 750 to 3500 mm and format thicknesses of 30 to 500 mm, said casting plant being equipped with an electromagnetic braking device for improving the product quality, it is proposed to dispose at least two poles (10) per mould broad side (3) symmetrically with respect to the perpendicular reference line (4) of the mould dip tube (2) such that the primary axes (12) of the poles’ outlet cross section (11_a) are aligned at a specific angle (α₁ and α₂) relative to the perpendicular reference line (4) of the mould dip tube (2).

Description

Electromagnetic brake device on continuous casting molds

The invention relates to a method and apparatus for casting of liquid metals, in particular of liquid steel materials for the production of slab and thin slab products with format widths of 750 to 3500 mm and format thicknesses of 30 to 500 mm in a continuous casting, the product quality with a Electromagnetic braking device is equipped, consisting of coils with cores and yokes, through the generated magnetic field effect, the flow conditions are influenced within the liquid metal in the mold.

To improve the product quality by positively influencing the flow conditions within the continuous casting mold, it is known to equip these with an electromagnetic brake. This consists of coils with cores and yokes, with which magnetic fields are generated, which act on the existing flow conditions of the steel bath within the mold. For the fullest possible unfolding of the effectiveness of the magnetic fields, it is necessary to bring the magnetic fields as close as possible to the continuous casting mold. Usually, therefore, either the electromagnetic brake systems moved up after the onset of the mold in the casting machine hydraulically or electromechanically to the mold or they are installed in different arrangements firmly on the mold of the continuous casting. Essentially, in this case, the coil or coil combinations are each positioned with core from the outside of the mold or on the water-flowed water box or copper plate back, or the coil is stationary fixed to the steel structure and a movable core is moved through them into the mold.

BESTATIGUNGSKOPIE Thus, WO 2004/022264 A1 discloses an electromagnetic braking device for molten steel flowing into a continuous casting mold, comprising at least one magnetic coil with a ferromagnetic core that can be assigned to the wide sides of the casting mold. To reduce the oscillating masses and at the same time to increase the magnetic field strength, the core consists on the one hand of a magnet coil receiving, movable in the distance to the broad side walls main part and on the other hand in water boxes of the mold fixedly arranged additional parts, the core parts in collapsed operating position u -shaped yokes to form a closed magnetic flux.

From DE 10 2004 046 729 A1 a magnetic brake for a continuous casting mold is known, in which a magnetic field generated by permanent magnets is intended to bring about an influence on the flow of the liquid metal. In order to obtain a variation of the magnetic field strength, the permanent magnets arranged on the mold are differently adjustable for a different field strength distribution in groups. In this case, it is also provided that permanent magnets are arranged in the water box of the continuous casting mold and can be set for direct contact with the mold plate.

In DE 600 16 255 T2 an apparatus for casting metals is described with an electromagnetic brake, comprising magnetic cores which are permanently attached to one side of the mold so that they cover substantially the entire width of the mold except for a central portion and which are connected to a detachable yoke, wherein the winding is arranged around the yoke such that the central axis of the winding extends substantially parallel to a longitudinal axis of the mold and at right angles to the casting direction of the mold. By the measures it is achieved that the originally vertically directed flow velocity of the liquid molten metal in the area of the inlet pipe is reversed, at least greatly reduced (decelerated). In addition, there is a horizontal and vertical rotation of the melt. Finally, DE 602 19 062 T2 describes a device for casting metals, wherein magnetic elements comprising magnetic cores and electrical conductor windings for generating a magnetic field are arranged along each longitudinal side of the mold by an applied polyphase alternating voltage. By arranging such magnetic elements, movements of the molten material in the area of the upper surface in the end portions are affected and braking of the downward movement of the melt is enabled.

Based on this described prior art, the object of the invention is to provide for the poles of the electromagnetic brake systems of continuous casting molds such an arrangement and orientation, by influencing the liquid flow of the liquid steel from the dip tube of the mold can be performed in a direct manner.

The object is achieved with the characterizing features of claim 1, characterized in that for direct or immediate electromagnetic interference emerging from the Kokillentauchrohr liquid jets per Kokillenbreitseite at least two symmetrically to the vertical reference line of the Kokillentauchrohrs arranged poles with their main axes of the outlet cross-section at a certain angle Ci ₁ and α ₂ are aligned accordingly.

By aligning the poles of the electromagnetic brake device in the main flow direction of the immersed tube flow, the electromagnetic braking device acts as locally acting field directly exiting the Kokillentauchrohr liquid jets directly or directly with respect to their direction, their velocity profile and turbulence structure. By virtue of the liquid jets modified in this way, the emergence of harmful fluctuations in the speed of the bath is advantageously at least limited and can thus be controlled. The achievable results Among other things, there are low turbulences in the bath level, less undesirable inclusions of, for example, casting powder or slag, and a homogeneous temperature distribution and thus an overall improved quality of the cast products and an increase in the casting speed.

Due to the concentrated effect of the pole arrangement according to the invention and Polausbildung the electromagnetic braking device on the dip tube flow of the required power requirement of the braking device is very low and is only about ^Λ A to Vz of the otherwise applied electrical power, with no format width-dependent adaptation of the braking device, but only a setting of Field strength is to be provided in dependence on the throughput.

The braking device is operated essentially with a permanent field and adjustable field strength by means of direct current; but also operation with changing field strength and possible direction reversal by means of alternating current can be carried out alternatively.

The poles of the electromagnetic brake device according to the invention have an arbitrary outlet cross-section with the expression of a major axis, wherein this outlet cross-section may be formed, for example, as a triangle, as a rectangle, as an arbitrary polygon or with an arcuate contour.

According to the invention, the orientation of the major axes is defined so that the major axes of the poles with the vertical reference line of the chill tube above the poles at an angle αi between 1 ° to 89 ° or alternatively below the poles at an angle α ₂ between Cut 1 ° to 89 °. The settings of the angles α-i and α ₂ are set manually before the operation of the continuous casting by rotation of the poles or they are adjusted according to a further embodiment of the invention during operation of the continuous casting variable variable by motor rotation of the poles and then changed if necessary, wherein the motorized setting of the angle takes place for example by means of motor, hydraulic rotary drive, hydraulic or pneumatic cylinder. The possible pivot points of the poles are preferably on their main axis, but they can also be arranged depending on their geometric configuration alternatively outside the poles.

In one possible embodiment of the invention, the electromagnetic braking device with coils, cores and yoke is arranged directly on the mold, so that it oscillates together with the mold during operation of the continuous casting machine.

In a further possible embodiment of the invention, the electromagnetic braking device is arranged so as to be stationary apart from the mold, so that it now does not participate in the oscillation of the mold.

Finally, a separation of the electromagnetic Bremseinrich- device is possible, for example, the pole ends on the mold and the coils, the sub-core and the yoke are arranged on the stationary machine design.

Further advantages and details of the invention are explained in more detail below with reference to exemplary embodiments illustrated in schematic drawing figures. Show it:

1 is a mold with electromagnetic braking device in a perspective view, FIG. 2 is a mold for thick slabs with electromagnetic braking device in a sectional side view,

3 shows a mold for thin slabs with electromagnetic braking device in a sectional side view,

Fig. 4 u. 5 the mold of FIG. 2 with rotatable poles in different angular position,

6 - 8, the mold with rotatable poles in different angular position in an alternative Polausbildung,

Fig. 9 exemplary Polausbildungen showing the main axis.

1 shows the mold 1 of a continuous casting plant with arranged in the lower region of the mold dipping tube 2 electromagnetic braking device in a perspective view. The electromagnetic braking device, consisting of the cores 14, the yoke 14 'and the magnetic coils 13, according to the invention is arranged so that on each Kokillenbreitseite 3 two poles 10 are opposite to each other. They are aligned symmetrically with respect to the vertical reference line 4 of the chill tube 2 to the main flow direction of the dip tube flow, that its main axis 12 of the outlet cross-section αi cuts this reference line 4 at a certain angle. By referring to the alignment of the poles 10 to the main flow direction of the immersion tube flow, the liquid jets flowing into the mold 1 are influenced directly by the magnetic field lines 15 established between the poles 10. The main flow direction of the dip tube flow which is not shown in the perspective view of FIG. 1 is shown in FIGS. 2 to 5 in a sectional side view. FIG. 2 shows a mold 1 for thick slabs with the main flow direction 5 of the dip tube flow emerging laterally from the mold dipping tube 2 at approximately a right angle. Corresponding to this main flow direction 5, in each case one pole 10 is arranged laterally in the lower region of the chill dipping tube 2 such that the main axes 12 of the outlet cross section 11 _{a of} each pole 10 intersect the vertical reference line 4 of the chill dipping tube 2 at an angle α. Since the point of intersection is above the poles 10, this angle is denoted by cti.

FIG. 3 shows a mold 1 for thin slabs with main flow direction 5 of the dip tube flow exiting laterally from the mold dipping tube 2 at approximately 45 °. The arrangement of the poles 10 with respect to this main flow direction 5 is compared with Figure 2 changed so that the intersection of the major axes 12 of the outlet section 11 _{a of} each pole 10 with the vertical reference line 4 of the Kokillentauchrohrs 2 is now below the poles 10, which is why this angle to Distinction to the angle αi α ₂ is designated.

An alternative embodiment of an electromagnetic braking device for a thick slab mold 1 according to FIG. 2 for adaptation to changed conditions of the liquid jets emerging from the mold dipping tube 2 is shown in FIGS. 4 and 5. The poles 10 of this embodiment are formed around a lying on the main axes 12 of the outlet cross-section 11 _a pivot point 20 in the clockwise direction 18 and opposite 19 rotatable. In FIG. 5, both poles 10 have been rotated according to the direction of rotation 18 and 19, respectively, relative to the original position of FIG. 4, whereby the original angle Ch of FIGS. 2 and 4 has been increased to a new value α-T in FIG.

Exemplary possible rotations of the poles 10 are shown in FIGS. 6 to 8. The poles 10 formed with an arcuate contour of their outlet cross-sections 11 _e are arranged on the mold 1 symmetrically to the vertical reference line 4 of the mold cavity 2 in the region of the outlet opening 6. net. FIG. 6 shows an assumed initial position. Compared with this initial position of Fig. 6, the left pole 10 in the direction of rotation 18, ie in the clockwise direction and the right pole 10 were rotated in the opposite direction in the direction of rotation 19 by an angle of 5 ° inward, whereby the position shown in Figure 7 of the poles has been. An opposite to the initial position of Figure 6 opposite rotation of the pole 10 to the outside by an angle of 20 ° results in the pole position shown in Figure 8.

In order to show which outlet cross sections 11 of the poles 10 can be used according to the invention, a selection of possible different outlet cross sections 11 is given in FIG. The outlet cross sections 11 are shown with the main axis 12 of the outlet cross section 11, the upper row of figures showing an assumed starting position and the lower row of figures showing the end position rotated in the direction of rotation 19 by an angular amount. In detail, the following outlet cross sections are shown from left to right:

Rectangular outlet cross-section 11 _a Triangular outlet cross-section 11 _b Cross-section formed as a polygon 11 _C Oval outlet cross-section 11 _d

LIST OF REFERENCE NUMBERS

I mold 2 mold dipping pipe

3 Kokillenbreitseite

4 vertical reference line of the chill dipping tube

5 main flow direction of the dip tube flow

6 exit opening of the Kokillentauchrohrs 10 Pol

II _a- e outlet cross section of the pole

12 major axis of the outlet cross section of the poles

13 solenoid coils

14 core 14 'yoke

15 magnetic field lines

16 intersection above the poles

17 intersection below the poles

18 Direction of rotation (clockwise direction) 19 Direction of rotation (counterclockwise) 20 Fulcrum αi Angle between perpendicular reference line of the chill tube and main axis in the exit section of the poles with intersection above the poles α ₂ Angle between vertical reference line of the chill shroud and main axis in the exit section of the poles with intersection above the poles

Claims

claims

1. Process for the casting of liquid metals, in particular of liquid steel materials for the production of slab and thin slab products with format widths of 750 to 3500 mm and format thicknesses of 30 to 500 mm in a continuous casting plant equipped with an electromagnetic braking device to improve product quality is, consisting of coils (13) with cores (14) and yoke (14 '), by the generated magnetic field effect, the flow conditions within the liquid metal in the mold (1) are affected, characterized in that for direct or immediate electromagnetic interference of the at least two poles (10) arranged symmetrically with respect to the vertical reference line (4) of the mold dipping pipe (2) with their main axes (12) of the outlet cross-section (11 _a - _e ) corresponding to the main flow direction (3) emerging from the mold dipping pipe (2). 5) of the dip tube flow in a certain W Inel (αi and α ₂ ) are aligned.

2. The method according to claim 1, characterized in that the alignment of the main axes (12) is performed so defined that the main axes (12) of the poles (10) with the vertical

Reference line (4) of the chill tube (2) above the poles (10) at an angle (α-i) between 1 ° to 89 ° or alternatively below the poles (5) at an angle (α ₂ ) between 1 ° to 89 ° to cut.

3. The method according to claim 2, characterized in that the angles (αi or α. ₂ ) are set manually by rotation of the poles (10) prior to operation of the continuous casting plant.

4. The method according to claim 2, characterized in that the angle (αi or α ₂ ) during operation of the continuous casting variable adjusted by manual or motorized rotation of the poles (10) and changed if necessary.

5. The method of claim 1, 2, 3 or 4, characterized in that in dependence on the flow rate of the mold (1), the field strength of the braking device is set.

6. The method according to one or more of claims 1 to 5, characterized in that the braking device is operated with a permanent field and adjustable field strength by means of direct current.

7. The method according to one or more of claims 1 to 5, characterized in that the braking device is operated with alternating field strength and possible direction reversal by means of alternating current.

8. mold (1) of a continuous casting plant for casting of liquid metals, in particular of liquid steel materials for the production of slab and thin slab products with format widths of 750 to 3500 mm and format thicknesses of 30 to 500 mm, the out to improve product quality with an electromagnetic braking device is equipped, consisting of coils (13) with cores (14) and yoke (14 '), by the generated magnetic field effect, the flow conditions within the liquid metal in the mold (1) are influenced, in particular for carrying out the method according to claims 1 to 7, characterized in that per Kokillenbreitseite (3) at least two poles (10) to the vertical reference line (4 ) of the Kokillendauchrohrs (2) are arranged symmetrically so that the direction of the major axes (12) of the outlet cross-section (11 _ae ) of the poles (5) correspond substantially to the main flow directions (5) of the dip tube flow and the main axes (12) while the vertical reference line ( 4) of the Kokillentauchrohrs (2) above the poles (10) at an angle (αi) between 1 ° to 89 ° or alternatively below the poles (10) at an angle (α ₂ ) between 1 ° to

Cut 89 °.

9. mold (1) according to claim 8, characterized in that the poles (10) in the form of a major axis (12) with an arbitrary outlet cross-section (11 _a - _e ), for example as a triangle, rectangle, any polygon or with an arcuate Contour are formed.

10. mold (1) according to claim 8 or 9, characterized in that the poles (10) in a fixed geometric arrangement on the mold (1) at an angle (αi or α ₂ ) to the vertical reference line (4) of the Kokillentauchrohrs (2) are aligned.

11. mold (1) according to claim 8 or 9, characterized in that the poles (10) for manual or motorized adjustment of the angle (αi or OC ₂ ) are designed to be correspondingly rotatable before or during operation of the continuous casting.

12. mold (1) according to claim 11, characterized in that the motor adjustment of the angle, for example by means of motor, hydraulic rotary drive, hydraulic or pneumatic cylinder takes place.

13. mold (1) according to claim 11 or 12, characterized in that a possible pivot point (20) of the pole (10) on its main axis (12).

14. mold (1) according to claim 11 or 12, characterized in that a possible pivot point (20) outside of the pole (10).

15. Mold (1) according to one or more of claims 8 to 14, characterized in that the electromagnetic braking device with magnetic coils (13), cores (14) and yoke (14 ') is arranged directly on the mold (1) and during the operation of the continuous casting plant together with the mold (1) oscillates.

16. mold (1) according to one or more of claims 8 to 14, characterized in that the electromagnetic braking device is arranged separately from the mold (1) stationary and does not carry out the oscillation of the mold (1).

17. mold (1) according to one or more of claims 8 to 14, characterized in that the electromagnetic braking device is separated so that, for example, the pole ends on the mold (1) and the magnetic coils (13), the core (14) and the yoke (14 ') are arranged on the fixed machine construction.