METHOD AND DEVICE FOR THE CONTACTLESS DETERMINATION OF AT LEAST ONE PROPERTY OF AN AT LEAST PARTIALLY MELTED ENDLESS STRAND

Abstract

The present invention relates to a method for contactless determination of at least one property of an at least partially melted quasi-endless strand during a casting process of the quasi-endless strand, which cools down within a cooling zone, allowing successive hardening of the quasi-endless strand, comprising at least the following steps: Emitting a first signal, in particular a first radar signal, in the form of radiation by an emission device, in particular a radar emission device, Generating a second signal, in particular a second radar signal, at least partly by an interaction of the first signal with a region of the quasi-endless strand, receiving the second signal by a reception device, in particular by a reception device for radar signals, determining at least one property of the quasi-endless strand on the basis of the second signal, wherein at least the step of interacting takes place within the cooling zone or upstream of the cooling zone (K), in particular immediately after exit from a mold. The present invention further relates to a device for casting a material, in particular a metal, into a quasi-endless strand in the context of a continuous casting process and for contactless determination of at least one property of the at least partially molten quasi-endless strand during casting of the quasi-endless strand, comprising a mold adapted to form said quasi-endless strand, a cooling zone in which said quasi-endless strand cools down, whereby successive hardening of said quasi-endless strand is enabled, an emission device, in particular a radar transmitter, adapted to emit emitting a first signal in the form of radiation, in particular as a first radar signal, a reception device, in particular a radar receiver, which is arranged to receive a second signal, in particular a second radar signal, whereby the second signal being generated at least partially by interaction of the first signal with a region of the quasi-endless strand within in the cooling zone or upstream of the cooling zone (K), in particular immediately after exit from a mold, a data processing unit arranged to determine at least one property of the quasi-endless strand on the basis of the second signal. According to the invention, a corresponding use is also provided.

Claims

1. Method for contactless determination of at least one property of an at least partially melted quasi-endless strand (100, 100b) during a casting process of the quasi-endless strand (100, 100b), which cools down in a cooling zone (K), whereby a successive hardening of the quasi-endless strand (100, 100b) is enabled, comprising at least the following steps: Emitting (S01) a first signal (102), in particular first radar signal (102), in the form of radiation by an emission device (11, 13, 31, 32), in particular a radar emission device (11, 13, 31, 32), generating (S02a) a second signal (101), in particular second radar signal (101), at least partly by interaction (S02b) of the first signal (102) with a region of the quasi-endless string (100, 100b), receiving (S03) the second signal (101) by a reception device (12, 13, 31, 32), in particular by a reception device (12, 13, 31, 32) for radar signals, determining (S04) at least one property of the quasi-endless string (100, 100b) on the basis of the second signal (101), characterized in that at least the step of interacting (S02b) is performed within the cooling zone (K) or upstream of the cooling zone (K).

2. Method according to claim 1, the method further comprising: A step of handling (S05) a defect or anomaly in the quasi-endless strand (1), which is detected on the basis of the determined properties or secondary variables determined therefrom, in particular by aborting the casting process or generating a protocol or instruction, which is suitable for removing the region of the quasi-endless strand (9) affected by the defect subsequently during further processing, further in particular by cutting out the region affected by the defect during successive cutting of the quasi-endless strand into slabs.

3. Method according to claim 1 or 2, wherein the at least one particular property of the quasi-endless strand is selected from the group consisting of distance, width, thickness, density, temperature, and homogeneity.

4. Method according to any one of claims 1 to 3, wherein steps S01 to S03 are carried out from two different viewpoints, in particular from two substantially oppositely arranged positions with respect to the quasi-endless strand.

5. Method according to claim 4, wherein, according to step S04, a width of the quasi-endless string is determined by subtracting the sum of two certain distances and a distance of the two different positions from each other, or wherein, according to step S04, a width of the quasi-endless string is determined by subtracting two certain distances from the distance of the two different positions from each other, in particular when emitting (S01) and receiving (S02) are substantially at a right angle to a surface of the quasi-endless string.

6. Method according to claim 4, wherein according to step S04, a width of the quasi-endless string is determined by subtracting the sum of two certain distances and a distance of the two different positions from each other, or wherein according to step S04, a width of the quasi-endless string is determined by subtracting two certain distances from the distance of the two different positions from each other, wherein said emitting (S01) and said receiving (S02) are substantially at a right angle to a surface of said quasi-endless string, wherein, moreover, in said determining (S04) at least one of the two distances, a trigonometric function is employed to correct the effect of an angular deviation from said right angle measurement.

7. Method according to any one of claims 1 to 6, wherein a wall (51, 52, 61, 62) is arranged between the emission device and the quasi-endless strand, wherein the wall comprises a recess (7) through which signal propagation is enabled.

8. Method according to claim 7, wherein the recess is dimensioned to form an effective opening angle for the emission device that is at most 80% of the emission opening angle of the emission device.

9. Method according to claim 7 or 8, wherein the distance between the emission device and the wall (51, 52, 61, 62) is at least 10 cm.

10. Method according to any one of claims 1 to 9, wherein the quasi-endless strand is produced in a continuous casting process.

11. Method according to any one of claims 1 to 10, wherein the emission device and/or the reception device are arranged within the cooling zone or upstream of the cooling zone (K), in particular immediately after exit from a mold.

12. Method according to any one of claims 1 to 11, wherein the emission device and the reception device comprise a shared device, in particular a shared radar transceiver.

13. Method according to any one of claims 10 to 12, wherein the emission device and/or the reception device comprise a horn antenna and/or a phased array antenna.

14. Device for casting a material, in particular a metal, into a quasi-endless strand (100, 100b) in the course of a continuous casting process and for contactless determination of at least one property of the at least partially melted quasi-endless strand (100, 100b) during casting of the quasi-endless strand (100, 100b), comprising:: a mold (4) which is suitable to form the quasi-endless strand (100, 100b), a cooling zone (K) in which the quasi-endless strand (100, 100b) cools down, whereby successive hardening of the quasi-endless strand (100, 100b) is enabled, an emission device (11, 13, 31, 32), in particular a radar emitter (11, 13, 31, 32), which is arranged to emit a first signal (102, 103) in the form of radiation, in particular as a first radar signal (102, 103), a reception device (12, 13, 31, 32), in particular a radar receiver (12, 13, 31, 32), which is set up to receive a second signal (101, 103), in particular a second radar signal (101, 103), whereby the second signal (101, 103) being generated at least partly by an interaction of the first signal (102, 103) with a region of the quasi-endless strand (100, 100b) within the cooling zone (K) or upstream of the cooling zone (K), a data processing unit adapted to determine at least one characteristic of the quasi-endless strand (100, 100b) based on the second signal (101, 103).

15. Use of an emission device (11, 13, 31, 32) and a reception device (12, 13, 31, 32), in particular for radar signals (101, 102, 103), for contactless determination of at least one property of an at least partially melted quasi-endless strand (100, 100b) during a casting process of the quasi-endless strand (100, 100b), which cools down within a cooling zone (K), whereby a successive hardening of the quasi-endless strand (100, 100b) is enabled, wherein the emission device (11, 13, 31, 32) and the reception device (12, 13, 31, 32) are arranged to determine the at least one property of the quasi-endless strand (100, 100b) within the cooling zone (K) or upstream of the cooling zone (K).

16. Use of the method according to any one of claims 1 to 13 or an emission device according to claim 14 for contactless determination of oscillation marks of the quasi-endless strand.

Description

LIST OF FIGURES

[0073] The present invention is explained in more detail below with reference to the embodiments given in the schematic figures. The following are shown:

[0074] FIG. 1 an apparatus for carrying out a continuous casting process (continuous casting plant);

[0075] FIG. 2 an apparatus for carrying out a continuous casting process (continuous casting plant), which is provided for the process according to the invention in accordance with one embodiment, which is set up in particular to determine a thickness of a quasi-endless strand;

[0076] FIG. 3 an apparatus for carrying out a continuous casting process (continuous casting plant), which is provided for the process according to the invention in accordance with one embodiment, which is set up in particular to determine a thickness of a quasi-endless strand;

[0077] FIG. 4 an apparatus for carrying out a continuous casting process (continuous casting plant), which is provided for the process according to the invention in accordance with one embodiment, which is set up in particular to determine a thickness of a quasi-endless strand;

[0078] FIG. 5 a simplified schematic representation of an apparatus for carrying out a continuous casting process (continuous casting plant), which is provided for the process according to the invention in accordance with one embodiment, which is set up in particular to determine a width of a quasi-endless strand.

DESCRIPTION OF FIGURES

[0079] A continuous casting plant conventionally operates as shown in FIG. 1. The continuous casting plant is filled with liquid steel 2 or a molten metal 2 in a casting mold 4, the mold 4, open at the bottom. Primary cooling takes place in the area of the mold 4. The molten metal, which is still liquid and has a temperature of approx. 1,600° C., flows into a channel, also named mold, where the molten metal is cooled down. Heat is dissipated via the mold walls so that the metal solidifies and forms a load-bearing shell. This means that a crust is formed on the outside during the cooling process. The solidification temperature of steel, for example, is around 1,150° C. to 1,500° C., depending on its composition. The so-called strand shell contains a liquid core. The solidified strand shell is continuously drawn out of the mold and passed on supported by rollers 5. At the primary cooling station, about 12% of the energy of the metal is conventionally extracted by means of a water cooling system in the molds. The mold walls typically consist of coated or uncoated copper plates. The back of the copper plates is cooled by contact with cooling water. The cooling water is pumped through cooling slots or cooling gaps provided for this purpose between the mold wall and the support plates. The flow rate of the cooling water is high and selected to achieve a heating of 6 to 15° C. The heat dissipation of about 2 megawatts per square meter achieved in the mold is high. The energy is dissipated unused via the heat exchanger and cannot be fed to a recovery system in this form. The first station, the mold, is followed by secondary cooling by spray cooling with water or an air-water mixture. In secondary cooling, heat is removed from the strand by spray cooling 6, radiation and closed machine cooling until solidification occurs or the stability of the shell is ensured without cooling. The solidified metal strand is then cut into ingots, known as slabs, blooms, billets, or strand pieces and further processed or stored temporarily. The energy content of these ingots or billet pieces still corresponds to about 50% of the energy content of the liquid metal.

[0080] FIGS. 1-5 show continuous casting plants and are described—wherever possible—together. In this regard, the devices of FIGS. 2-5 are arranged to enable the present invention to be put to use. In particular, the devices of FIGS. 2, 3 and 4 are arranged so that the present invention can be put to use to determine a thickness of a quasi-endless strand. In particular, the apparatus of FIG. 5 is arranged to put the present invention to use to determine a width of a quasi-endless strand. For numerous processes, the determination of a width is particularly relevant.

[0081] The ladle 1 comprises a molten metal 2, which flows from there into the distributor 3, and from there via the pouring tube 10 successively into the mold 4, thus forming the quasi-endless strand 100.

[0082] Shown in all figures is a vertical casting process, but the invention can also be used with other casting processes such as a horizontal casting process.

[0083] The generation and successive cooling of the strand are carried out, for example, as described further above. Guiding and successive cooling of the strand are performed here by the rollers/rolls 5 and the cooling devices 6.

[0084] The finished quasi-endless strand 100b is for example cut by a cutting device 8, for example such as one or more cutting torches or one or more plasma torches 8 into slabs 9 or billets.

[0085] In FIG. 2, the apparatus is practicing the method according to the invention. In particular, a RADAR emission device 11, a RADAR reception device 12 and a RADAR transceiver 13 are shown, which are adapted to be used in a process according to the invention.

[0086] In this example, a RADAR emission device 11 and a RADAR reception device 12 separate therefrom are used on the left-hand side. On the right-hand side, the RADAR transceiver 13 comes into use in this example. However, this arrangement is merely an example. Both on the left-hand and on the right-hand side a choice can be made—independently of each other—whether to use a transceiver or separate emission and reception device. All combinatorial choices (1. left: Transceiver, right: Transceiver; 2. left: Transceiver, right: Transmitter+Receiver; 3. left: Transmitter+Receiver, right: Transceiver; 1. left: Transmitter+Receiver, right: Transmitter+Receiver) are compatible with the present invention. For example, two RADAR transceivers 31 and 32 are shown in FIG. 3.

[0087] A further, i.e. additional, measurement is also possible on the horizontal strand. For this purpose, a RADAR emission device 21, a RADAR reception device 22 and a RADAR transceiver 23 are shown in FIG. 2. An additional measurement has numerous advantages. For example, it is possible to check on the horizontal strand whether a defect previously detected during an initial measurement on the vertical strand could be eliminated. Also, the material has cooled down much further and the measurement therefore provides measured values that are closer to the measured values of the finished product.

[0088] However, this arrangement of a RADAR emission device 21, a RADAR reception device 22 and a RADAR transceiver 23 in FIG. 2 is also merely an example. Both on the upper and lower side a choice can be made—independently of each other—whether a transceiver or separate emission and reception devices are to be put to use. All combinatorial choices (1. above: Transceiver, below: Transceiver; 2. above: Transceiver, bottom: Transmitter+Receiver; 3. above: Transmitter+Receiver, bottom: Transceiver; 1. Top: Transmitter+Receiver, below: Transmitter+Receiver) are possible and also compatible with a combination with the teaching according to the invention. For example, two RADAR emission devices 36 and 38 and two RADAR reception devices 37 and 39 are shown in FIG. 3.

[0089] In all figures, the positioning of associated emission devices and reception devices is merely exemplary. For example, in FIG. 2, RADAR emission device 11 may also be located where the RADAR reception device 12 is shown, while likewise the RADAR reception device 12 is located where RADAR emission device 11 is shown.

[0090] FIG. 3 further discloses walls or covers 51, 52, 61, 62 having recesses which allow signal transmission. The recesses may also be filled with a suitable material. The advantages of the walls or covers are apparent from the description of the invention and its further embodiments.

[0091] The apparatus of FIG. 5 is particularly adapted to enable the present invention to be put to use for determining a width of a quasi-endless strand. This is particularly reflected in the FIG. 5 in the position and orientation of the RADAR emission device 11, the RADAR reception device 12 and the RADAR transceiver 13 (and possibly the walls 51, 52). The orientation of the RADAR signals 101, 102, 103 is also adjusted accordingly. In FIG. 5, these are incident on or emanate from the side of the quasi-endless strand 100.

[0092] Also in FIG. 5, the positioning of associated emission devices and reception devices is merely exemplary. For example, in FIG. 5, the RADAR emission device 11 may also be located where the RADAR reception device 12 is shown, while likewise the RADAR reception device 12 is located where RADAR emission device 11 is shown.

[0093] In this example of FIG. 5, a RADAR emission device 11 and a RADAR reception device 12 separate therefrom are used on the left-hand side. On the right-hand side, the RADAR transceiver 13 is used in this example. However, this arrangement is merely an example.

[0094] Both on the left and on the right side a choice can be made—independently of each other—whether to put to use a transceiver or separate emission and reception device. All combinatorial choices (1. left: Transceiver, right: Transceiver; 2. left: Transceiver, right: Transmitter+Receiver; 3. left: Transmitter+Receiver, right: Transceiver; 1. left: Transmitter+Receiver, right: Transmitter+Receiver) are compatible with the present invention. The skilled person will recognize that the terms “left” and “right”, which refer to the respective figure, are defined differently here in the context of FIG. 5 than in the context of FIGS. 1-4.

[0095] For numerous processes, the determination of a width is particularly relevant. For the sake of clarity, FIG. 5 is shown in simplified form.

LIST OF REFERENCE SIGNS

[0096] 1 ladle
2 molten metal
3 distributor
4 mold
5 rollers/rolls
6 cooling devices
7 recess
8 cutting devices/torches
9 slab
10 pouring tube
11 RADAR emission device
12 RADAR reception device
13 RADAR transceiver
21 RADAR emission device
22 RADAR reception device
23 RADAR transceiver
31 RADAR transceiver
32 RADAR transceiver
36 RADAR emission device
37 RADAR reception device
38 RADAR emission device
39 RADAR reception device
51 wall/cover
52 wall/cover
61 wall/cover
62 wall/cover
100, 100b quasi-endless strand
101 second RADAR signal (secondary signal)
102 first RADAR Signal (primary signal)
103 first RADAR-Signal (primary signal) and second RADAR signal (secondary signal), spatially overlapping

Further Revelations

[0097] In particular, the invention comprises a process as defined herein, wherein the continuous casting process uses a mold through which the quasi-endless strand is formed, wherein steps S01 to S03 are performed immediately downstream of the mold, i.e. upstream of the cooling zone (K).

[0098] For example, a method may be provided wherein the emission device and/or the reception device is protected by a diaphragm formed of PTFE, which is stable at least up to a temperature of 260° C., and/or ceramic, which is stable at least up to a temperature of 1,400° C.

[0099] In one embodiment of the method, it may be provided that the emission device and/or the reception device is protected by a first diaphragm, which is in particular designed as a pinhole aperture, and further the hole is covered by a second diaphragm, wherein the second diaphragm is formed of PTFE.

[0100] Advantages due to the protection of a diaphragm, in particular a pinhole aperture, are the increased quality and the resulting high accuracy of the measuring arrangement. Furthermore, there is no need for an additional spacer plate (such as a wall or shield) as in the case of an open or at least semi-open measurement arrangement, so that the emission device and/or the reception device can be positioned directly in the cooling zone. Even in the case of maximum temperatures that may be generated during continuous casting (as defined herein), the properties of the quasi-endless strand (100, 100b) remain very well determinable.

[0101] In one embodiment of the method, it may be provided that the emission device and/or the reception device comprise a lens construction. Based on an appropriate lens construction, for example, high temperatures generated during continuous casting (as defined herein) can compensate for possible deviations (i.e., aberration or imaging errors) that may arise during the determination of at least one property of the quasi-endless strand (100, 100b).