ES2523772T3 - Metallurgical container and procedure for manufacturing a vessel wall - Google Patents

Abstract

Metallurgical container with a hollow space for the treatment of a first liquid metal or for the liquefaction of a metal, in which the container comprises a coolable wall (1) with a hot side directed towards the hollow space and with a cold side away from the hollow space of a second metal and in which the wall (1) is equipped in the area of the hot side with light waveguides (5, 6, 7) arranged close to the surface for data detection of the metallurgical vessel or of the first metal, in which the light waveguides (5, 6, 7) are inserted into grooves (2, 3, 4; 28), which are made from the hot side in the wall (1) and the grooves (2, 3, 4; 28) are closed with the light waveguides introduced through the filler piece (8, 9, 10; 27) on the hot side, characterized in that the grooves (2, 3, 4; 28) have a cross section that tapers towards their groove bottom (25).

Description

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55 E11701474

11-12-2014

DESCRIPTION

Metallurgical container and procedure for manufacturing a vessel wall

The invention relates to a metallurgical container with a hollow space for the treatment of a first liquid metal or for the liquefaction of a metal, in which the container comprises a refrigerable wall with a hot side directed towards the hollow space and with a side cold away from the hollow space of a second metal and in which light wave guides are introduced for the detection of data from the metallurgical container or the first metal in the wall of the container. In this case, the first metal is especially steel, but it can also be another metal. The second metal is especially copper, but another metal can also be provided. The invention also relates to the use of light wave guides in a wall of the container as well as to a method for manufacturing the wall for the metal container.

A series of devices are known for the generation of steel, which process on the road from the blast furnace and the converter raw, predominantly hot, crude irons, in combination with scrap, mineral, spongy iron and other contribution materials. In the same way, foundry containers are used, for example electric arc furnaces, in which predominantly cold or preheated contribution materials such as scrap iron and spongy iron are used. Both shells and also arc furnaces and other devices for casting or storing molten metal are designated as metallurgical vessels.

In DE 10 2008 060 507 A1, DE 10 2008 029 742 A1 and DE 10 2008 060 032 A1, the temperature measurement in a die of a foundry installation with the aid of a fiber optic measurement procedure is described. In this case, sensors are used to measure the temperature in at least one copper plate on the wall of the shell. The sensors are connected to a temperature detection system.

As sensors, light wave guides are used, through which laser light is conducted. Grooves are formed on the outer side of the copper plates, in which the light wave guides are laid. The detection of the temperature by means of light waveguides allows a considerably lower cable expenditure than the use of thermo elements in the shell. In addition, considerably less work and cost jack is needed for the installation of the fibers in the copper plate of the shell. The use of the light wave guides also allows a higher local resolution than can be achieved in the case of the use of thermo elements, which are inserted in drills. A light wave guide can replace more than one hundred thermo elements together with the corresponding cables.

The light wave guides are laid, for example, in the form of a meander between the cooling channels on the rear side, that is, on the cold side, of a copper plate of a slotted slot. The light wave guides can be cast by means of molten resin in the grooves. A closure is also known by means of other components or by means of galvanically applied layers.

From DE 10 2008 006 965 A1, a process for determining a radiation measurement for a thermal radiation from a voltaic arc that burns between an electrode and the casting in a voltaic arc furnace for the manufacture of liquid metal, in general steel, which is used when the radiation strikes a delimitation of the arc furnace.

In the electric arc furnace, liquid metal is produced that results from a molten solid material, perhaps scrap or reduced iron, using other contribution materials. To this end, energy is introduced by means of one or several electrodes for the smelting of the smelting material in the arc furnace, in general, in the form of a voltaic arc between the electrode and the smelting material. So that the smelting can be carried out in the most efficient way possible, it is about introducing, if possible, all the energy prepared by the arc into the smelting material. In this case, foundry material is understood as solid material of cast iron, liquid metal and / or slag.

By virtue of the usual mode of operation in current arc furnaces, however, it may happen that the arc burns freely during the smelting process, that is, the thermal radiation generated by the arc, which is configured between the electrode and foundry material, largely reaches a delimitation of the arc furnace, in particular a refrigerated wall of the arc furnace. In this way, the energy consumption of the furnace is increased, so that, on the one hand, it reintroduces energy from the arc furnace only to a reduced extent in the smelting material and, on the other hand, if necessary, the Cooling power for cooling the oven walls, to protect the wall / copper staves.

In the known procedure, an electrode current fed to the electrode is detected, so that oscillations of the structural sound of the arc furnace are detected and a current evaluation signal associated with a range is calculated from the electrode current detected. frequency of the electrode current detected, so that from the oscillations detected the structural sound is calculated a

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55 E11701474

11-12-2014

oscillation evaluation signal, which is associated with a frequency range of structural sound vibrations. In this case, a quotient of the oscillation evaluation signal and the current evaluation signal for at least one frequency common to the electrode current detected and the structural sound oscillations detected are formed as a measure for the thermal oscillation. Calculate the radiation measurement.

On the wall or in the panels of the oven container, that is, in the outer delimitation of the oven container, structural sound sensors are arranged for the detection of oscillations in the oven container. The signals, which are transmitted from them, are preferably conducted, at least partially, through a waveguide conductor.

It is known to install light wave guides on the side away from the hollow space that contains the liquid metal, that is, the cold side, of the wall plates that are made of copper in grooves. During the introduction from the cold side, in the case of changes in the temperature, there are frequently rising times, that is, the times until a value of 68% of the temperature value to be reached is reached, of two or three seconds. Such long rise times disqualify the light waveguides for the purpose of regulating the level of the laundry. Therefore, in this case we refer to the use of radiometric systems, which use radioactive radiation, in which rise times can be made from medium to one second.

It is known from JP 09 047855 A, the use of light wave guides on the inner side of the walls of an extrusion die. The light wave guides are housed, respectively, in slots and are embedded in a mixture of an aluminum oxide powder and an epoxy resin with good thermal conductivity. The filling dough may be coated with layers of copper and nickel.

The purpose of the invention is to improve a known metallurgical container of the type mentioned at the beginning, the use of light wave guides in a wall of the container and a known method for manufacturing a wall for the container, so that it is possible an exact detection of temperature data and expansion data, with respect to the container and the material in the container.

According to the invention, this task is solved as indicated in claims 1, 12 and 14 of the patent, respectively.

The concept of "metallurgical vessel" comprises in the sense of the present invention all types of metallurgical vessels, also casting furnaces, in particular electric arc furnaces, and also shells, in particular for extrusion casting.

In the sense of the present invention, the concept of "wall" also includes individual wall elements, for example wall plates, as part of an entire wall of the container. Conversely, the concept of wall plate should be understood as both an individual element and also as the entire wall of the container.

Through the introduction according to the invention of light wave guides on the walls of the electric arc furnace, the temperatures or the expansion or oscillation behavior of the metallurgical vessel on the hot side at different heights of the surface can be represented container. In this case, dynamic modifications are detected in the same way throughout the process, for example conditioned by modifications of the circulation in the laundry. The concept enables a representation of the thermal and mechanical load of the vessel wall in each operating state, also as a function of time. In this way it is also possible to selectively search for errors (of the process), such as longitudinal cracks in the wall or casting adhesions on the hot side, as a cause of the characteristic signatures on the subsequent molten product.

In this new concept, the light wave guides are not introduced, as is known until now, from the cold side surrounded by cooling water, but directly from the hot side thermally charged on the vessel wall. This allows very close supervision in time of the staves against overload situations. In the event that the LWL light waveguide indicates an incipient overheating on the copper stave, the heating power of the electrode can be reduced. The exact arc furnace can be operated closer to the operating limit with more heating power through the exact measurement, since no unnecessarily high safety reserve is needed for the protection of the staves.

To this end, a continuous groove is milled on the hot side, which is subsequently closed on the hot side by means of the filling piece of the base material of the hot side. This filling piece is preferably melted through friction welding and stirring again with the base body. In this case, the groove depth must be sized so that the thermal load through the welding procedure cannot damage the light wave guides.

This concept presents the advantage that the measuring fiber is arranged very close to the area, in which the casting process takes place, for the use of a casting die. In this way, light wave guides can be used for temperature measurement or for dilation measurement, without having to tolerate rise times or dead times that are too long. In the case of using the fiber process

10

fifteen

twenty

25

30

35

40

Four. Five

50 E11701474

11-12-2014

Bragg for temperature measurement in waveguide conductors laid out in accordance with the invention, in the case of using a sufficiently thin envelope tube, which surrounds the light waveguide, rise times of only 0 are achieved, 1 s. This means that in the case of the introduction of a light waveguide surrounded by an envelope tube in the groove of a hot side / copper plate, a dead time rise or an additional rise time of another 0 can still be accepted, 25 s, without obtaining a result that is worse than in a known radiometric procedure. Through the invention such good measurement accuracy can be achieved with dead times and reduced rise times when the grooves, in which the light wave guides are located, have only a reduced depth of approximately 3-12 mm. This means that the light wave guides are in accordance with the invention, for example, in the range of 3-12 mm behind the hot side. By means of milling, for example by means of a milling cutter, grooves are manufactured, which have a width of one to two millimeters. In these, the light wave guides wrapped with enveloping tubes can be inserted. The grooves are then filled with preference by means of metal strips adapted to the width of the grooves as fillers. Finally, the metal strips are connected in their lateral edges with the material of the copper plates. This can be done by means of a plurality of technologies, for example by welding or tin plating.

According to the invention, the grooves have a cross section that narrows towards the bottom of the groove. This prevents that during friction and stir welding a bolt that advances with pressure on the welding material can press the filler piece too deeply and thus can crush the envelope tube of the light waveguide.

Advantageous developments of the invention are deduced from the dependent claims, the description and the drawing.

Advantageously, the filling pieces, which close the grooves, are made of the same material as the wall plates.

To this end, the grooves advantageously have a cross section at least essentially trapezoidal. Through the trapezoidal cross-section, the oppression of the filling piece and the crushing of the wrapping tube can be prevented.

It is understood that the filling pieces preferably have a cross section adapted to the grooves, in particular a cross section equally trapezoidal.

Preferably, the filling pieces have an insignificant under-measure in front of the grooves, in particular in the area, which is connected to the surface of the wall pieces. In this way it is possible that the filling parts can be connected by means of mechanical actuation, in particular by means of lamination or welding, with the material of the wall plates, without damaging the enveloping tubes of the light waveguides at the bottom of the groove.

The connection between the filler pieces and the material that surrounds them laterally from the wall plates is carried out by means of a welding process, namely by friction welding, in particular by friction welding and agitation .

Advantageously, but not necessarily, the light wave guides are inserted in enveloping tubes, in particular metal.

To this end, it can also be provided with advantage that the filler pieces and the wall plate are coated on their surfaces accessible from the outside with a layer of nickel or chrome.

With advantage, the light wave guides have a diameter of approximately 0.15 mm. The wrapping tubes adapted for this purpose have a diameter of approximately 0.5 to 1 mm. Preferably, the filling pieces have a width of 1 to 2 mm.

Light waveguides can be used according to the measurement technique in multiple ways. According to their object of application, they are placed loose in the grooves or holes, in particular for the measurement of temperature, since for the measurement of temperature it is important that the light wave guides, by virtue of their modification of the temperature, can be compressed and dilated by themselves without impediments.

Preferably, the light wave guides are laid in the area in the vicinity of the copper staves. This has the advantage that the heating power of the oven electrode (s) can be reduced again as soon as the light wave guides allow the failure of the staves in the near future.

On the other hand, for a measurement of the expansion it is important that the light waveguides are fixedly connected, at least punctually, but preferably over their entire length with the surrounding material of the wall and / or with the filling parts . This form of fixing is necessary so that the dilations of the container are

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55 E11701474

11-12-2014

transmitted immediately on the light wave guide and the light wave guide can emit signals, which represent the dilatations of the metallurgical vessel. You can also record and evaluate the time curve of the dilations, oscillations and / or temperatures, as they are recorded in each case with the light wave guides. It is understood that in this metallurgical container, both loose waveguides and also glued in the grooves or holes on the hot side of the wall plates can be present in accordance with their different application objects.

The invention also relates to the use of light wave guides in walls of metallurgical vessels. The light waveguides measure the temperature of the wall, of the metal casting of the first metal in the vessel or the dilations or mechanical oscillations of the wall. Preferably, the data is used, for example, for the regulation of the laundry level.

The invention also relates to a process for the manufacture of a wall, comprising wall plates, of a metallurgical container. For this purpose, it is provided in accordance with the invention that grooves are manufactured on the hot side of the wall through erosion of the material, in particular through milling, such that the light wave guides are placed in the grooves, the grooves are closed by means of filling pieces and then the filling parts are connected through a welding procedure, in particular through friction welding and agitation, with the material of the wall plates.

The invention will be explained in detail in the following examples with the help of the figures. In this case:

Figure 1 shows a top plan view in perspective on a wall plate of a foundry shell, in which slots are formed for the accommodation of light wave guides.

Figure 2 shows a filler piece and a plate with a groove, into which the filler piece is inserted, respectively, in the cross section, and

Figure 3 shows a side perspective view of another wall plate, in which a closed groove is made with a trapezoidal filling piece and receiving a light wave guide, in connection with an arrangement schematically represented for friction welding and stirring.

A wall plate 1 (figure 1) of a metal container, for example of a die for metal casting, in particular steel, is preferably made of copper and has on the side, which is directed towards the casting space which receives the liquid metal, the so-called hot side, that is, in the representation on the upper side, grooves 2, 3 and 4, which have a rectangular, square or trapezoidal cross-section and whose bottom is preferably rounded. Slots 2, 3 and 4 are inserted with light wave guides 5, 6 and 7, respectively. From the upper side / hot side they are covered on the light wave guides 5, 6 and 7 in the slots, respectively, with padding piece 8, 9 and 10, respectively. Additionally, fasteners 13, 14 and 15, respectively, which fix the waveguide guides, can be provided for fixing either on the outer lateral ends 11, 12 or also in the area between the two ends 11, 12 light 5 to 7 and / or the filling part 8 to 10 that are on them, while these are connected by means of a friction welding process with zones 16, 17, 18 and 19 that are connected therein the wall plate 1.

The light wave guides 5 to 7 are constituted of an optical conductive material with an index of refraction that is reduced in cross section from the inside out; preferably they are received in each case by metal casings or caps and can tolerate, for temperature measurement, temperatures of up to 600 ° C as permanent charge. On its rear side, the wall plate 1 is flooded with cooling water. The cooling water circulates through channels (not shown).

The light wave guides 5 to 7 have on the end side lens connectors, to decouple the light waves and feed them to an evaluation unit. Since the light waves are conducted on lens connectors from the component housing in the respective measurement position to the evaluation unit, a robust transmission of the signals is achieved. The light wave guides 5 to 7 have a diameter of for example 0.15 mm without the envelope tube and for example 1 mm including the envelope tube. Measuring procedures include a measurement procedure of Bragg fiber grating Procedure- (FBG = Fiber Bragg Grating) and / or the OTDR procedure (OTDR = Optical Time Domain Reflectometry) as well as the OFDR (Optical Frequency Domain Reflectometry) procedure.

The filling pieces 8, 9, 10 have, as shown in Figure 2 with the help of the filling piece 8, a cross section 20 preferably with trapezoidal shape. In this regard, the side walls 21, 22 form with an upper edge 23 of the filling piece 8 preferably the same obtuse angle α, which is also present between the side walls 23, 24 of the groove 2 and the zones 16, 17 that connect in each case laterally in them. On the bottom 25 of the groove 2, which is preferably rounded, is the light wave guide 5 surrounded by a wrapping tube 25. The wrapping piece 8 can also have an insignificant under-measure in front of the groove 2. It is then mechanically pressed into slot 2 and connected,

10

fifteen

twenty

25

30

35

40 E11701474

11-12-2014

for example, by means of welding or tinning with the zones 16, 17 surrounding the groove 2.

When a filler piece 27 (Figure 3) is sufficiently accurately adapted to the shape of a groove 28 in a workpiece 29, that is, for example, a copper plate for the cast iron, which must be covered by Up from the hot side, the enclosure 27 is connected, after it has been introduced into the groove 28, preferably through friction welding and stirring with lateral zones 30, 31. To this end, an apparatus for conducting stir welding 32 above the wall plate 1 in the direction of an arrow A on the development of the groove 28 on the filling piece 27, such that a welding pin 34 placed on a projection of the tool 33 It performs rotational movements simultaneously with the contact with the filling piece 27. In this case, the filling piece 27 and the zones 30, 31 are heated so strongly that as a consequence of the heat of friction between them they initiate a union of the m Aterial, which has high stability.

The introduction of the light wave guides in the area of cooling elements, for example the so-called copper staves, on the hot side of the metallurgical vessel allows a very fast and rational way of introducing the fibers more advantageously.

The temporary development of the temperature of the wall of the container or of the metallic laundry in the container and / or the temporary development of the expansion of the container can be detected with the help of light wave guides and can be used, for example, for the optimization / increase of the power of the electrodes. The power of the electrodes is controlled in accordance with the time curves considered, such that the walls of the container are not damaged. In particular, through the evaluation of the time curves, the limit of failure of the vessel can be calculated and the electrical power of the electrodes can be reduced in a timely manner before reaching the limit of failure.

List of reference signs

one

Wall

2

Groove

3

Groove

4

Groove

5

Light wave guide

6

Light wave guide

7

Light wave guide

8

Filling piece

9

Filling piece

10

Filling piece

eleven

Extreme

12

Extreme

13

Bra

14

Bra

fifteen

Bra

16

Zone

17

Zone

18

Zone

19

Zone

twenty

Cross section

twenty-one

Side wall

E11701474

11-12-2014

22

Side wall

2. 3

Side wall

24

Side wall

25

Background

5

26 Wrap tube

27

Filling piece

28

Groove

29

Workpiece

30

Zone

10

31 Zone

32

Welding apparatus with stirring

33

Tool shoulder

3. 4

Welding pin

35

Wash

fifteen

36 Spear

37

Spear tube

38

Spear head

39

Application device

40

Rake

twenty

41 Feeding duct

Claims (14)

5 10 fifteen twenty 25 30 35 40 Four. Five 50 E11701474 11-12-2014 1.-Metallurgical container with a hollow space for the treatment of a first liquid metal or for the liquefaction of a metal, in which the container comprises a refrigerable wall (1) with a hot side directed towards the hollow space and with one side cold away from the hollow space of a second metal and in which the wall (1) is equipped in the area of the hot side with light wave guides (5, 6, 7) arranged near the surface for the detection of data from the metallurgical or first metal container, in which the light wave guides (5, 6, 7) are inserted in grooves (2, 3, 4; 28), which are made from the hot side on the wall (1) and the grooves (2, 3, 4; 28) are closed with the light wave guides inserted through a filler (8, 9, 10; 27) on the hot side, characterized in that the grooves (2, 3 , 4; 28) have a cross section that narrows towards its groove bottom (25). 2. A container according to claim 1, characterized in that the filling pieces (8, 9, 10; 27) are made of the same material as the wall (1). 3. - Container according to claim 1 or 2, characterized in that the grooves (2, 3, 4; 28) have a cross section essentially trapezoidal. 4. Container according to one of claims 1 to 3, characterized in that the filling pieces (8, 9, 10; 27) have a cross-section adapted to the grooves (2, 3, 4; 28), in particular a cross section equally trapezoidal. 5. Container according to one of claims 1 to 4, characterized in that the filling pieces (8, 9, 10; 27) have opposite the grooves (2, 3, 4; 28), in particular in the area , which is connected on the surface of the adjacent wall areas, an insignificant inframeasure. 6. Container according to one of claims 1 to 5, characterized in that the filling pieces (8, 9, 10; 27) have a width of 1 to 2 mm. 7. A container according to one of claims 1 to 6, characterized in that the wall with the filling pieces (8, 9, 10; 27) on the hot side is covered with a layer of nickel or chrome. 8. A container according to one of claims 1 to 7, characterized in that the light wave guides (5, 6, 7) are inserted into the grooves in enveloping tubes, in particular metal. 9. Container according to claim 8, characterized in that the wrapping tubes (26) have a diameter of approximately 0.5-1 mm. 10. Container according to one of claims 1 to 9, characterized in that the light wave guides (5, 6, 7) have a diameter of approximately 0.15 mm. 11. Container according to one of claims 8 to 10, characterized in that the light wave guides (5, 6, 7) for temperature measurement are lying loose in the slots (2, 3, 4; 28 ), drills or enveloping tubes or are fixedly connected for the detection of dilatations of the metallurgical vessel promptly or over its entire length with the surrounding material of the wall, of the filling parts and / or of the wrapping tubes, so that the wrapping tubes are connected for the measurement of the expansion, in turn, with the wall . 12. Use of a light wave guide on the wall of a metallurgical container according to one of claims 1 to 11, characterized in that the light wave guide (5, 6, 7) is used to measure the temperature of the metal casting of the first metal in the container, or dilations of the container, so that as data the time curves of the wall of the container or of the metal casting or of the dilations of the container are detected and used for the optimization / increase of the power of the electrodes, without damaging the walls of the container, or because shortly before reaching the limit of failure, under the measurement values of the light waveguides the power is limited of the electrodes. 13. Use according to claim 12, characterized in that the time curve of the measured dilations of the container represents the vibration behavior of the container. 14.-Procedure for the manufacture of a wall of a metallurgical vessel, in which the wall (1) has a hot side and a cold side, into which light wave guides (5, 6, 7) are introduced for the detection of data on the wall in slots (2, 3, 4; 28), in which the introduction of the light wave guides comprises the following steps: formation of the grooves (2, 3, 4; 28) in the wall (1) through erosion of the material, in particular by milling, and 8 E11701474 11-12-2014
introduction in the light waveguides (5, 6, 7) in the slots (2, 3, 4; 28), characterized by the closing of the grooves (2, 3, 4; 28) on the hot side by means of filling pieces (8, 9, 10; 27), so that the filling parts (8, 9, 10; 27) they are connected by friction welding, in particular by friction welding and agitation, with the wall material. 9