EP2310539A1

EP2310539A1 - Method and devices for regulating the flow rate and for slowing down melt streams through magnetic fields in the tapping of metallurgical containers such as blast furnaces and melt furnaces

Info

Publication number: EP2310539A1
Application number: EP09781571A
Authority: EP
Inventors: Hans-Uwe Morgenstern
Original assignee: TMT Tapping Measuring Technology GmbH
Current assignee: TMT Tapping Measuring Technology GmbH
Priority date: 2008-08-07
Filing date: 2009-08-06
Publication date: 2011-04-20
Anticipated expiration: 2029-08-06
Also published as: DE102008036798A1; JP2011529795A; WO2010015684A1; RU2011106577A; US8658084B2; UA103775C2; ATE557106T1; JP5635986B2; RU2515778C2; US20110175265A1; ZA201100943B; EP2310539B1; BRPI0917123A2; CN102177258A

Abstract

The invention relates to a method for regulating the flow rate and for slowing down melt streams through magnetic fields in the tapping of metallurgical containers such as blast furnaces and melt furnaces. The method is characterized in that the melt stream is routed in a closed routing element using at least two magnetic fields disposed in series one after the other in the flow direction of the melt, said magnetic fields having a constant polarity opposite to one another, in such a way that the magnetic field lines transversally penetrate the melt flow across the entire cross section thereof and such that opposite voltages are induced in the melt stream by the magnetic fields, there being at least three eddy current fields produced thereby in the melt stream that are disposed axially one after the other, and that due to the interactions between the magnetic fields and the eddy currents forces are generated that can be used to reduce the flow rate of the melt stream.

Description

description

Title: Methods and devices for regulating the

Flow velocity and braking of melt streams by magnetic fields during the tapping of metallurgical containers such as cooking oven and furnace

The invention relates to a method and devices for controlling the flow rate and for braking non-ferromagnetic melt streams by magnetic fields during tapping of metallurgical containers such as blast furnace and furnace.

With the parallel patent application 10 2008 036 799.0-24 a generic control device is proposed, which is characterized by a core of ferromagnetic material having two poles forming a gap for receiving a conductive element for a melt stream, and arranged on the core induction coils for Generation of a magnetic field, which acts on the melt flow m arranged between the poles guide.

In this control device, a closed magnetic circuit is used to generate a magnetic field through which a voltage is induced in the melt stream, are caused by the eddy currents in the melt stream, which generate forces in cooperation with the magnetic field, which reduce the flow rate of the melt stream and increase again and can slow down the melt stream. The invention has for its object to develop a method and apparatus for controlling the flow rate and for braking non-ferromagnetic melt streams, which make it possible to enhance the magnetic field acting on the melt stream and the eddy currents generated by this to increase the forces acting on the melt stream ,

This object is achieved by the method with the features of claim 1 and the control devices according to claims 6 and 1.

The dependent claims include advantageous and expedient developments of the method according to claim 1 and the control devices according to claims 6 and 7.

The inventive method for controlling the flow velocity and for braking non-ferromagnetic melt streams during tapping of metallurgical containers such as blast furnaces and furnaces is characterized in that the melt stream in a closed guide by at least two in the flow direction of the melt in series successively arranged magnetic fields with a constant, opposite Polarity is conducted such that the magnetic field lines transversely penetrate the melt stream over its entire cross-section and induced by the magnetic fields in the melt stream opposing voltages, are generated in the melt stream at least three consecutive axial eddy current fields, and that by the interaction of magnetic fields and eddy currents are generated by the forces Flow rate of the melt stream in dependence on the strong magnetic field can be reduced.

In a preferred embodiment of this method, a double, opposing voltage is induced in the melt flow by the magnetic flux of a closed magnetic circuit via two opposing magnetic fields between each two poles, such that there is a mutually reinforcing effect on the current intensity of the central axial eddy field.

Due to the double utilization of the magnetic flux of a closed magnetic circuit, the magnetic resistance in the iron core of the magnetic circuit and thus the internal losses of the magnetic circuit are approximately halved.

A variant of the method consists in that voltages are induced in the melt stream by the magnetic flux of two closed magnetic circuits arranged behind one another via two opposing magnetic fields between each two poles, such that a mutually reinforcing effect on the current intensity of the central eddy current field results.

By means of a dense rear-end arrangement of the magnetic fields acting on the melt stream m a gap between the two poles of a magnetic circuit it is achieved that the gradient of the decrease of the magnetic flux to the lateral edge of the gap is as large as possible and that the path length of the eddy currents in shortens the eddy current fields generated in the melt stream and reduces the electrical resistance.

The basic concept of the invention is based on the fact that the double utilization of the magnetic flux of a closed magnetic circuit, a double, opposite, eddy current amplifying voltage is induced in the molten metal, wherein the magnetic resistance in the iron core and thus the internal losses are approximately halved.

By the arrangement of several self-contained magnetic circuits with a double utilization of the magnetic flux, the influence on the melt flow is disproportionately increased by a disproportionate increase in the number of steeper gradients of the magnetic flux, by a disproportionate increase in the number of amplified eddy current fields with their respective double interaction with the magnetic fields and by a double utilization of the inducing effect of the electric induction coils. The multiple use and the associated distribution of the eddy currents in the individual eddy current fields in the melt stream have a multiple and analog effect on the strengthening of the forces acting on the melt stream.

Devices for controlling the flow rate and for braking melt streams, which operate in accordance with the methods described above and which are used in particular during the tapping of blast furnaces, are explained below with reference to schematic drawing figures, which represent the following:

Fig. 1 is a perspective view of a

Regulating device according to a parallel patent application 10 2008 036 799.0-24 with a magnetic field of constant polarity for controlling the flow velocity and for braking a melt stream, Fig. 2 is a diagram showing the course of

Magnetic flux density of the magnetic field generated by the control device according to FIG. 1 over the length of the exposure section of the magnetic field to the melt flow,

3 is a perspective view of a first embodiment of the control device according to the invention,

Fig. 4 is a diagram showing the course of

Magnetic flux density of the two magnetic fields generated by the control device according to FIG. 3 as well as with the course of the magnetic flux density of the two magnetic fields of a control device of the same type, structurally identical,

5 is a perspective view of another embodiment of the control device,

Fig. 6 shows the arrangement of a control device in front of the outlet opening of a taphole channel of a blast furnace and

Fig. 7 is a schematic representation of the double utilization of the magnetic flux inducing effect of electric induction coils.

The control device 1 according to FIG. 1, which is preferably used for tapping blast furnaces for regulating the flow velocity and for braking a melt stream 2 by means of a magnetic field 3 of constant polarity, has a core 4 of ferrorαagnetischen material which is formed as a yoke 5 with two poles 6, 7, which form a gap 8 for receiving a guide element 9 in the form of a tube 10 for passing the melt stream 2. On the yoke 5 sit two induction coils 11, 12 for generating a closed magnetic circuit 13 with the magnetic field 3 of constant polarity between the two poles 6, 7, which is characterized by field lines 14.

The melt stream 2 enters the magnetic field 3 in the region of 15 m and leaves it again in the region 16. When the melt stream 2 enters the magnetic field 3, a voltage 17 is induced in the melt stream in a plane perpendicular to the magnetic field lines 14 Rule of Lenz axial eddy currents 18 are generated in the melt stream 2. Due to the interaction of magnetic field 3 and eddy currents 18, the so-called Lorentz forces 19 are produced in the melt stream 2, which are opposite to the flow direction a of the melt stream 2 and which thereby exert a braking effect on the melt stream 2, by which the flow velocity of the melt stream is reduced.

When leaving the exit region 16 of the magnetic field 3 2 eddy currents 20 are generated in the melt stream, which in turn generate by cooperation with the magnetic field 3 Lorentz forces 21 which are opposite to the flow direction a of the melt stream 2 and thus an additional braking effect to the braking effect of Lorentz Forces 19 in the inlet region 15 of the melt stream into the magnetic field 3 triggers. For better illustration, the induced voltages 17 and the eddy currents 18, 20 are shown rotated by 90 ° from the horizontal plane in the vertical plane in Figure 1.

The diagram of Figure 2 shows the course of the magnetic flux density in Tessla of the generated with the control device 1 of Figure 1 magnetic field 3 over the length L of the exposure section of the magnetic field 3 to the melt stream 2. Because of the magnetic saturation in iron, it is not economically with only one more reasonable effort possible to achieve a magnetic flux density that is above 2 Tessla. The expansion of the magnetic field 3, which is illustrated by the widening magnetic field lines 14, in the gap 8 between the two poles 6 and 7 causes the curve of magnetic flux density flat and far to the two edges of the gap 8 between the poles 6, 7 expires , Within the magnetic field 3, a corresponding electrical voltage 17 is induced in the melt stream 2 as a function of its strength and polarity, which acts as a driving force for the eddy currents 18, 20, so that the eddy currents can close the circuit only outside the magnetic field 3. The lower gradient of the decrease in magnetic flux density results in expanded eddy current fields 18, 20 with long current paths. In accordance with this comparatively long path length, comparatively high electrical resistances occur and accordingly correspondingly reduced eddy current strengths result.

The forces resulting from the interaction of eddy currents and magnetic field depend inter alia on the strength of the eddy currents, which, in turn, are inter alia dependent on the length of the current path. The shorter the current path, the lower the electrical resistance and the higher the resulting eddy current under otherwise given conditions. Since the If current paths can only close outside of the magnetic field, a magnetic field that drops as sharply as possible to zero at the edge would be ideal for this purpose. In reality, a magnetic field but runs far, as can be seen from Figure 2.

In addition, the eddy current on the resulting current path normally interacts only once with a magnetic field and therefore only generates a force once.

So now if two magnetic fields with reversed polarity are placed close to each other, such that the magnetic field lines cross the melt flow transversely, then there are the following advantages:

1. The magnetic field has the steepest possible gradient to the edge in the direction of the inverse second magnetic field and thus generates the shortest possible current path, as Figure 4 illustrates.

2. The fact that the adjacent magnetic field has the opposite polarity, it acts on the same eddy current loop in the same direction and amplifying / doubling. Reference is made to FIG. 4, which will be explained in detail below.

The new control device 22 of Figure 3, in particular when tapping blast furnaces to control the

Flow rate and for braking a melt stream 2 in the taphole of a blast furnace is used, is equipped with a formed by two yokes 24, 25 core 23 of ferromagnetic material, the two in series successively arranged pole pairs 26, 27, each with two poles 28, 29; 30, 31. The two pole pairs 26, 27 form two successively arranged column 32, 33 for receiving a guide element 9 for passing the melt stream 2, which is formed as a pipe 10 or channel. On the four pole pieces 34- 37 of the two yokes 24, 25 of the core 23 are four induction coils 38-41 for generating two in

Flow direction a of the melt stream 2 in series successively arranged magnetic fields 42, 43 in a closed magnetic circuit 44 between the poles 28, 29; 30, 31 of the two pole pairs 26, 27 are arranged, wherein the two magnetic fields 42, 43 have a constant, opposite polarity. By the magnetic fields 42, 43 opposing voltages 45, 46 are induced in the melt stream 2, are generated in the melt stream two axially consecutive eddy current fields 47-49, such that a mutually reinforcing effect on the current of the central eddy current field 48 between the two outer eddy current fields 47, 49 results. Due to the interaction of magnetic fields and eddy currents, forces are generated in the melt stream through which the flow velocity of the melt stream can be reduced.

The control device can be extended to the melt flow as needed to increase the braking force acting on a melt stream by an even number of pole pairs over the length L of the exposure section of the magnetic fields.

The diagram according to FIG. 4 illustrates the course of the magnetic flux density in Tessla shown in a solid line of the two magnetic fields 42, 43 generated in a closed magnetic circuit 44 with the control device 22 shown in FIG. 3 over the length L of the acting section the magnetic fields on the melt stream and in dashed lines the magnetic flux density of the two magnetic fields of a similar, connected to the first control device 22 further control device.

The solid curve in Figure 4 illustrates that in the control device 22 of Figure 3, the magnetic flux in a closed magnetic circuit 44 is used twice and with mutually different polarity. The resulting increase in the magnetic flux density results in a corresponding increase in the eddy current intensity. The double use in a closed magnetic circuit takes place in opposite directions, that is, the magnetic flux is effective in both the positive and in the negative flow direction. This increases the usable magnetic flux density for eddy current formation from about 2 Tessla to 4 Tessla in the same magnetic circuit. Furthermore, the gradient for the decrease of the magnetic flux density in the region 50 shown in FIG. 4 between the two magnetic fields 42, 43 is particularly large. As a result, the path lengths of the eddy currents and thus the electrical resistances become smaller, which results in a corresponding increase in the current intensities.

The solid and the dashed lines in Figure 4 show the curve of the magnetic flux density over the length of the impact section of the magnetic fields on the melt stream of two successively arranged control devices according to Figure 3 with two consecutive closed magnetic circuits, each with a double use of the magnetic flux. FIG. 4 illustrates that, in the case of a regulating device with a closed magnetic circuit, a steep curve of the magnetic flux density results between two flat curves and that, in the case of two, one behind the other arranged control devices with two closed magnetic circuits and a double use of the magnetic flux in each magnetic circuit result in three steep curves between two flat curves of the magnetic flux density. As a result, the increase in impact is clearly disproportionate.

In the control device 22 according to FIG. 3, the gaps 32, 33 between the poles 28, 29 and 30, 31 and the magnetic fields 42, 43 acting in the gaps 32, 33 are close to one another. The magnetic fields 42, 43 are tightly bundled in the region 50 in which they abut each other despite high magnetic flux density. From the correspondingly shortened current paths of the eddy currents and the double effect of the eddy currents it follows that the effect of the electromagnetic influence on the melt current more than doubles-

FIG. 5 shows a further embodiment 51 of the regulating device, which has two control devices 1 according to FIG. 1 connected in series.

The control device 51 is equipped with two successively arranged cores 4, 4 of ferromagnetic material having a yoke 5 with two poles 6, 7, which form a gap 8, wherein by the two in series successively arranged column 8, 8 a guide element , In particular, a taphole channel of a blast furnace for a melt stream 2 is passed. The control device 51 further has two each on the pole pieces of the two yokes 5, 5 arranged induction coils 11, 12 for generating two consecutively arranged magnetic fields 42, 43 with opposite polarity in two separate, closed, opposing magnetic circuits 13, 13 a, wherein the magnetic fields 42 43 trigger in the melt stream 2 axial eddy currents to produce a force acting on the melt stream 2 braking force.

Compared with a control device according to Figure 3, which operates with a double use of the magnetic flux of a closed magnetic circuit, the control device 51 of Figure 5 with a simple use of the magnetic flux of two successively arranged, closed magnetic circuits has a poorer efficiency, but with this control device is an essential Reinforcing the eddy currents in the melt stream compared to the control device of Figure 1 achieved with a closed magnetic circuit with a simple use of the magnetic flux.

While it with a control device with the

Maximalausfuhrung the multiple use of the magnetic flux of a magnetic circuit is only possible to work with an even number of pole pairs, it is possible in a control device with a simple use of the magnetic flux of multiple control loops to work with both an even and an odd number of pole pairs. This may allow a better adaptation to limited space conditions.

The various control devices 22, 51 can be arranged as an attachment device in front of the outlet opening of the stitch hole of a blast furnace or in front of the outlet opening of the outflow channel of a melting furnace around the taphole channel or outflow channel.

From Figure 6, the arrangement of two successively arranged control devices 22 according to Figure 3 before the outflow opening of a taphole channel of a blast furnace. Within a housing 52 are two closed magnetic circuits 44 arranged with four columns 8 for the double use of the magnetic flux of each magnetic circuit. The melt stream 2 emerging from the taphole channel of the blast furnace flows through the pipe 10 passing through the four gaps 8 between the four pole pairs 26, 27; 26, 27 is guided, wherein the magnetic fields of the two magnetic circuits 44 act on the melt stream 2 over the length L.

FIG. 7 shows three iron-core induction coils 53-55 of a multiple arrangement of iron-core induction coils for producing closed magnetic circuits with double utilization of the magnetic flux to form eddy currents in a melt stream 2 flowing through a pipe 10. The coils 53-55 must be operated with alternately opposite polarity. In the illustration, the current directions of the respective right and left coil halves and the direction of the resulting magnetic flux 56 can be seen. Relative to the middle upper core 57 and its magnetic flux not only the associated coil 54 is effective, but also in this plane also the right half of the coil coil 53 of the left core 58 and the left half of the coil coil 55 of the right core 59. Thus acts In this example, the left-hand coil half of the coil 55 of the right-hand core 59 magnetizes both the right-hand core 59 and the central core 57. This applies mutatis mutandis to all coil halves in a multiple arrangement, so that it is in the display level with the exception of the extreme left and right coil halves to a double use of all coil halves and the currents flowing therein. This achieves a further disproportionate increase in the effect.

Claims

claims

1. A method for controlling the flow velocity and for braking non-ferromagnetic melt streams by magnetic fields during tapping of metallurgical containers such as blast furnaces and melting furnace, characterized in that the melt stream in a closed guide element by at least two in the flow direction of the melt in series successively arranged magnetic fields with a constant , is conducted in opposite polarity, such that the magnetic field flows through the melt stream transversely over its entire cross section and induced άen magnetic fields in the melt stream opposing voltages, are generated in the melt stream at least three consecutive axial eddy current fields, and that by the interaction be generated by magnetic fields and eddy currents forces by the flow rate of the melt stream as a function of the magnetic field strengths reduced w can ground.

2. The method according to claim 1, characterized in that the magnetic flux of a closed magnetic circuit via two opposing magnetic fields between each two poles induces a double opposing voltage in the melt stream, such that there is a mutually reinforcing effect on the current of the central eddy current field.

3. The method according to claim 2, characterized in that by the double utilization of the magnetic flux of the closed magnetic circuit of the magnetic resistance in Iron core of the magnetic circuit and thus the inner losses of the magnetic circuit are approximately halved.

4. The method according to claim 1, characterized in that induced by the magnetic flux of two successively arranged, closed magnetic circuits via two opposing magnetic fields between each two poles voltages in the melt stream, such that a mutually reinforcing effect on the current strength of the central axial Eddy current field results.

5. The method according to any one of claims 1 to 4, characterized by a dense Hmteremanderanordnung acting on the melt stream in a gap between the two poles of a magnetic circuit magnetic fields, such that the gradient of the decrease of the magnetic flux to the lateral edge of the gap is as large as possible and that the closely spaced arrangement of the column shortens the path length of the eddy currents m the eddy current fields generated in the melt stream and reduces the electrical resistance.

6. A device for controlling the flow rate and for braking non-ferromagnetic melt streams in the tapping of metallurgical containers such as blast furnace and furnace according to the method of the claims 1 to

3 and 5 characterized by at least one formed by two yokes (24, 25) core (23) of ferromagnetic material having two m row of successively arranged pole pairs (26, 27) each having two poles (28, 29, 30, 31) , the two successively arranged column (32, 33) for receiving a guide element (9) for a melt stream (2), and four on pole pieces (34-37) of the two yokes (24, 25) of the core (23) arranged induction coils (38-41) to produce two m A series of magnetic fields (42, 43) arranged in series in a closed magnetic circuit acting on the melt stream (2) in the guide element (9) passing through the gaps (32, 33) between the poles (28, 29; 30, 31). the two pole pairs (27, 28} is guided.

7. An apparatus for controlling the flow rate and for braking non-ferromagnetic melt streams in the tapping of metallurgical containers such as blast furnace and furnace according to the method of claims 1, 4 and 5, characterized by at least two m series successively arranged cores (4, 4) of ferromagnetic Material, each having a yoke (5) with two poles (6, 7), which form a gap (8), wherein a guide element (9) for a melt stream (9) through the two in series successively arranged column (8, 8) ( 2), and in each case two induction coils (11, 12) arranged on the pole shoes of the two yokes (5, 5) for generating two magnetic fields {42, 43} arranged in opposite directions in two separate, closed, counter-rotating magnetic circuits ( 13, 13a), wherein the magnetic fields in the melt stream (2) axial eddy currents to produce a acting on the melt stream Activate deceleration force.

8. Control device according to claim 6, characterized by an extension possibility of the same by even pole pairs.

9. Regulating device according to claim 7, characterized by an extension possibility of the same by even-numbered and odd-numbered pole pairs.

10. Control device according to one of claims 6 to 9, characterized by an arrangement thereof as an attachment means in front of the outlet opening of the needle hole channel of a blast furnace or the outlet opening of the drainage channel of a melting furnace.

11. A control device according to any one of claims 6 to 9, characterized by an arrangement thereof around the taphole of a blast furnace or the outflow channel of a melting furnace.