EP1174671A2 - Metallurgical vessel, in particular arc furnace, which remains vertical during tapping of the metal melt - Google Patents

Abstract

Metallurgical vessel, especially an electric arc furnace comprises: i) a tapping channel branch (8) running vertically downward from a vertical course of one or more tapping channels (6) in the tapping channel pipe wall (7); and (ii) a control stop (10) guided on the tapping channel axis (4a) in a pipe (9) from an upper closing position (11) sealed on the vessel base (1a) into a lower opening position (12). Preferred Features: The control stop and the pipe through which it is guided are made of boron nitride or a ceramic having low wettability. The tapping channels each have a pushing drive (14) and a rotating drive (15).

Description

The invention relates to a metallurgical vessel, in particular an electric arc furnace, this when tapping the molten metal in a vertical vessel position stands and has a floor cut.

Electric arc furnaces are mostly equipped with an oriel, in which there is an eccentric tap hole. During the melting the tap hole is not washed around by the molten metal. For parting off the vessel is tilted. The tap opening can be by means of a plug rod device or operated with a slide lock. The tapping channel is filled with a filling compound to prevent e.g. liquid steel with a final sheet metal plate of the closure comes into contact with it stuck by freezing. The free-flowing filling compound lies loosely on the sealing plate and allows movement when opening. The filling mass falls First open from the tapping channel. This is followed by the liquid metal (DE 32 30 646 C1).

However, such furnace vessels are expensive because a tilting device with a tilt drive necessary is. Due to the oriel, the furnace vessel is not rotationally symmetrical and therefore also expensive to manufacture.

The metallurgical vessel described at the outset only goes from a vertical one Position actuable racking, so that the oriel and a tilting device can be omitted.

The invention is based, for a metallurgical vessel in the vertical task Position propose a tap lock that can be reliably closed and it’s easy to open again, one portion at a time and then safe closing again allowed.

The object is achieved according to the invention in that the vertical Course of one or more tapping channels in the tapping tube wall in each case a tap-off branch diagonally downwards to the tap-off axis and at it then runs approximately vertically downwards and that one on the tapping axis Control plug in a tube from an upper one, on the bottom of the vessel in the closed position, which is sealed by a form fit, in the side Tap-off branch opening is also closed, in a lower open position is adjustable, in which the control plug the side tap branch opening released to the tapping channel. The advantages are secure locking when tapping in portions in a vertical vessel position. Also be created two sealing points for the molten metal. The racking is further sufficiently maintenance-free. The sealing effect takes place via a gap seal between two ceramic parts.

In an embodiment of the invention it is provided that the diameter is opposite the diameter of the tapping channel for the guidance of the control plug in a base block made of refractory material attached to the bottom of the vessel is inserted and that on the floor block a linear actuator and / or Rotary drive for the control plug is mounted and the linear actuator and the Rotary drive are connected to the control plug in terms of drive. During the The control plug seals against the melting phase of the metallurgical vessel top tip and during parting off the control plug seals in the filled Pipe.

For further security in the tapping area of a metallurgical vessel to create and thereby maintain a redundancy system, it is proposed that tapping channels arranged in pairs on the bottom of the vessel are mirror images each with a linear actuator and a rotary actuator are provided.

Further, the functional safety features are that a Section of the control plug near the bottom of the vessel is hollow and can be filled with filling compound by means of a side channel in the control plug and in the floor block a transport device for the filling compound in the closed position of the control plug can be introduced. As a result, the previous pourable filling compound on the sheet metal plate replaced and can therefore continue to be used as a filling compound. The Filling compound makes gap sealing easier.

Another improvement of the invention is given in that the tapping channel runs straight in the floor block and an arcuate outside the floor block Tapping tube is connected, the axis of which is perpendicular or that the tapping channel is curved in the floor block and is outside the floor block a vertical tapping tube connects.

A further development of the invention provides that the drives for the control plug each consist of either a gear transmission, the heat-resistant in one Enclosed housing and via a drive train with a remotely located Drive rotary motor is drivingly connected or from a hydraulic motor is formed, which is arranged outside the radiation region of the vessel is and cooperates with a piston surface of the control plug via a hydraulic line.

The desired tolerances between the control plug and the pipe can be heat-resistant can be achieved in that the control plug and the leading it Pipe are made of boron nitride or poorly wetted Ceramics. The latter is light and easy to edit.

An alternative to solving the problem is that on the bottom of the vessel a horizontal slide closure below the floor cut is arranged, with paired slide rods on at least one on Vessel-attached thrust gear connected to a drive motor and that a vertically rectangular floor tapping channel by means of two horizontal oppositely adjustable, covering the rectangular floor tapping channel Piston made of refractory material is closable. The mechanics are economical produced. The mode of operation is clearly manageable and the operation can be done with usual means.

The durability and the production are also advantageously influenced here, that the cylindrical pistons are guided in boron nitride sleeves and made of bomitride are executed.

Furthermore, the thermally required protective measures can also be used here can be applied in that each piston has its own drive, which consists of a hydraulic cylinder that is outside the radiation area of the vessel is arranged.

Fig. 1

einen senkrechten Querschnitt durch den Bodenbereich eines metallurgischen Gefäßes für ein erstes Ausführungsbeispiel, mit einem Schub- und einem Drehantrieb,

Fig. 2

einen senkrechten Querschnitt durch den Abstich wie Fig. 1 mit Ausbildung des Steuerstopfens und Spaltdichtung,

Fig. 3

einen senkrechten Schnitt wie die Fig. 1 und 2 mit einer alternativen Ausführungsform des Bornitrid-Rohrs und des Bomitrid-Steuerstopfens,

Fig. 4

den senkrechten Schnitt der Fig. 1 bis 3 während eines Freibohrens des linken Abstichkanals,

Fig. 5

den Schub- und Drehantrieb für den Steuerstopfen im Schnitt und vergrößertem Maßstab,

Fig. 6

einen senkrechten Schnitt durch eine Ausführungsform mit Füllmassen-Zuführung in einen hohlen Steuerstopfen,

Fig. 7

eine Einzelheit gemäß Fig. 6 in vergrößertem Maßstab,

Fig. 8

einen senkrechten Schnitt durch eine andere Ausführungsform mit Schieberverschluss,

Fig. 9

die Ausführungsform der Fig. 8 mit einer alternativen Antriebsgestaltung,

Fig. 10

einen horizontalen Schnitt durch die Ausführungsform der Fig. 9, mit geöffneten Kolben,

Fig. 11

den horizontalen Schnitt der Fig. 9 mit geschlossenen Kolben und

Fig. 12

einen vertikalen Schnitt durch den Bodenblock mit Inertgas-Spülung.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail below.
Show it:

Fig. 1

2 shows a vertical cross section through the bottom area of a metallurgical vessel for a first exemplary embodiment, with a thrust and a rotary drive,

Fig. 2

2 shows a vertical cross section through the tapping as in FIG. 1 with formation of the control plug and gap seal,

Fig. 3

2 shows a vertical section like FIGS. 1 and 2 with an alternative embodiment of the boron nitride tube and the bomitride control plug,

Fig. 4

1 to 3 during a drilling of the left tapping channel,

Fig. 5

the push and rotary drive for the control plug in section and on an enlarged scale,

Fig. 6

2 shows a vertical section through an embodiment with filler feed into a hollow control plug,

Fig. 7

6 shows a detail according to FIG. 6 on an enlarged scale,

Fig. 8

a vertical section through another embodiment with slide closure,

Fig. 9

8 with an alternative drive design,

Fig. 10

9 shows a horizontal section through the embodiment of FIG. 9, with the pistons open,

Fig. 11

the horizontal section of FIG. 9 with closed pistons and

Fig. 12

a vertical section through the floor block with inert gas purging.

The metallurgical vessel 1 with a vessel bottom 1a is in the embodiment from an electric arc furnace, which occurs when the molten metal is tapped 2 is in the vertical position of the vessel, so that a vertical tapping 3 also has a vertical axis position 4. The floor cut begins accordingly 3 with a vertical course 5 of one or more tapping channels 6 and runs further in the tap tube wall 7, each with a tap branch 8 obliquely down to the tapping channel axis 4a and then about vertically down. In the tapping channel axis 4a is in a concentric Tube 9 guided a control plug 10. The control plug 10 is located with its conical tip 10a in a form-fitting seal Closed position 11 (Fig. 1, left half). The side is in the tap tube wall 7 tapping branch opening 8a also closed. The Control plug 10 is adjustable (FIG. 1, right half) into a lower opening position 12, in which the control plug 10 has the lateral tapping branch opening 8a releases to tapping channel 6.

The tube 9 and thus the control plug 10 is approximately 25-30% larger in diameter 9a compared to the tapping channel diameter 6a. The tube 9 is in one bottom block 13 made of refractory material is attached to the bottom of the vessel 1a. A thrust drive 14 and a rotary drive 15 are on this floor block 13 stored for the control plug 10. The linear actuator 14 adjusts the control plug 10 in the closed position 11 or in the lower open position 12. The control plug 10 is guided closely in the tube 9. The control plug 10 and the pipe 9 are made and processed from boron nitride. The material boron nitride (BN) is through high temperature shock resistance and poor wettability by liquids and by very good lubricating properties and by good mechanical Machinability suitable for sealing.

During the melting phase, e.g. Can be 50 minutes Control plug 10 with its conical cap 10a against a corresponding one Conical ring surface in tube 9. During the tapping phase, e.g. 3 minutes lasts, the lowered control plug 10 seals due to its relatively close tolerance in tube 9 (with approx. 0.5 mm play). During this time the control plug leads 10 to seal against the molten metal 2, a rotary movement over the Rotary drive 15 relative to the tube 9.

As shown in FIGS. 1-4, on the bottom of the vessel 1a are via the bottom block 13 Tapping channels 6 arranged in mirror image in pairs, each with a linear actuator 14 and a rotary drive 15 are provided.

1, the control plug 10 is mounted in a tube 9, which as a sleeve a flange 9b resting on the base block 13 is designed.

In Fig. 2, the control plug 10 is in the left half of the illustration up to Drive the edge of the vessel bottom 1a into the closed position 11. This is done in a simple design of the linear actuator 14 used.

3, the tube 9 is designed as described. In comparison to 1 and 2, however, the tube 9 is a sleeve with a lower flange 9c executed and attached from below.

A further modification results from FIG. 4. In the bottom block 13 are again the two oblique tapping channels 6 are provided. The control plug 10 slides however directly in the bottom block 13, which forms the tube 9 itself. Here is only a tapping channel 6 available. In the vertical course 5 is a tap-off branch 8 arranged only for the supply of filling compound 16 by a conveyor 17. The second channel is filled with filling compound 16. The filling mass 16 (e.g. Sand) is driven by means of a motor-driven screw conveyor 28a (see FIG. 6) conveyed into the space above the control plug 10. The poetry will be there during the long melting phase of the vessel 1 of the sand introduced accepted. As soon as the control plug 10 is moved down to the To empty vessel 1, the filler channel is through the control plug there 10 closed. The sand lying on the control plug 10 cannot slip and blocks the hole against the penetration of molten metal 2. The tapping channel 6 is free. The sand and the molten metal 2 can do that Leave vessel 1. The seal between the pipe 9 and the control plug 10 in the open position is done again by the one described above Gap seals. Sealing is supported by sand remnants that because its spherical shape of the plug tip 10a into the space between the tube 9 and the control plug 10 remain. In this design, the closed Position at about 50 minutes when melting scrap the pipe 9 in 45 ° angle with flanges 9b or 9c changed by an automatic manipulator become.

5 shows an example of a thrust drive 14 with a rotary drive 15. On Drive rotary motor 17 drives a threaded spindle 19 via a gear transmission 18, on which a spindle nut 20 is guided. The spindle nut 20 is via a T-slot 21 connected to the control plug 10. On the spindle nut 20 is a Gear 22 is wedged and is connected via a further gear 23 via its shaft 23a and on the shaft 23a and on the housing 24 flange-mounted planetary gear 25 driven with its own drive motor 26. The drive rotary motor 17 and the Drive motor 26 are switched independently of one another. The drive rotary motor 17 adjusts the control plug 10 in the axial height and Drive motor 26 rotates control plug 10 by one in the manner described To produce a seal against the molten metal 2.

6, a portion 10b of the control plug 10 near the bottom of the vessel is hollow and filled with the filling compound 11, which through a side channel 27 in the control plug 10 and in the bottom block 13 by means of a conveyor 28 in the form of the screw conveyor 28a for the filling compound 16 in the closed position 11 of the control plug 10 is introduced and reaches and fills the section 10b near the vessel bottom.

The tapping channel 6 can only run straight in the bottom block 13 (FIGS. 1-5) and an arcuate tapping tube 29 can be connected outside the base block 13 be, whose axis 30 is perpendicular (Fig. 1 - 4).

Another guide of the tapping channel 6 provides that the tapping channel 6 in the Bottom block 13 runs curved and a perpendicular outside of the bottom block 13 extending tapping tube 31 connects.

The drives 14, 15 for the control plug 10 each consist of either Gear mechanism 18 and are heat-resistant enclosed in the housing 24 and over a drive train, not shown, with the remote drive motor 17 connected or as can be seen in Fig. 5, with the immediate, however, heat-protected drive rotary motor 17 or the drive 26. A another design provides a hydraulic motor (17; 26) that is outside the radiation range of the metallurgical vessel 1 is arranged and with a piston surface 32 of the control plug 10 via a hydraulic line (not shown) interacts.

6 shows the closed floor tapping 3. Only one tapping channel 6 is provided. In the bottom block 13, the tapping channel 6 runs straight, while the Tapping channel 6 has a curved part. The transport device 28 conveys through the screw conveyor 28a from a reservoir filler 16 through the channel 27 in the bottom block 13 to the portion 10a of the control plug near the bottom of the vessel 10. The tube 9 is fixed from below with a flange 9c. The one in Closed position 11 control plug 10 is due to the free-flowing filling compound 16 filled up in the floor rack 3. The molten metal is above the filling compound 16 2. All channels in the floor block 13 can be drilled out from the outside, if these do not run empty on their own.

In Fig. 7 the situation around the open floor tapping 3 is on an enlarged scale shown. The control plug 10 is connected via the in the T-groove 21 Threaded spindle 19 lowered into the lower open position 12, the Channel 27 is closed for the filling compound 16, so that the tapping branch opening 8a clears the way for the molten metal 2 through the tapping channel 6. Remnants of the filling compound 16 seal the control plug 10 all around at the edge, so no melt in the gap between the control plug 10 and that Tube 9 can get. For this reason, one can instead of boron nitride other ceramics can be selected.

(a) Öffnen des Bodenabstichs

• der Steuerstopfen 10 wird nach oben gefahren und zwar um ca. 50 mm, um die versinterte Schicht aus der Füllmasse 16 über den Steuerstopfen 10 aufzubrechen,
• der Steuerstopfen 19 wird dann nach unten gefahren in die Abstichposition (untere Öffnungsstellung 12), um der Metallschmelze 2 den Weg in den Abstichkanal 6 freizugeben.

(b) Schließen des Bodenabstichs

• Der Steuerstopfen 10 wird aus der unteren Position nach oben gefahren, bis die konische Kuppe 10a den Abstichkanal 6 versperrt, d.h. die Schließstellung 11 erreicht hat.
• Die Förderschnecke 28a fördert Füllmasse 16 durch den Kanal 27 in den hohlen, gefäßbodennahen Abschnitt 10b des Steuerstopfens 10,
• die Füllmasse 16 verdrängt die Metallschmelze 2 über dem Steuerstopfen 10 und füllt den Raum über dem Steuerstopfen 10 mit Füllmasse 16 aus, so dass ein späteres Öffnen wieder ermöglicht wird.

The floor tapping 3 can be operated in the following steps:

(a) Open the floor rack

• the control plug 10 is moved upwards, namely by approximately 50 mm, in order to break open the sintered layer from the filling compound 16 via the control plug 10,
• the control plug 19 is then moved down into the tapping position (lower opening position 12) in order to open the way for the metal melt 2 into the tapping channel 6.

(b) Closing the floor rack

• The control plug 10 is moved upwards from the lower position until the conical crest 10a blocks the tapping channel 6, ie has reached the closed position 11.
• The screw conveyor 28a conveys filling compound 16 through the channel 27 into the hollow section 10b of the control plug 10 near the bottom of the vessel,
• the filling compound 16 displaces the molten metal 2 above the control plug 10 and fills the space above the control plug 10 with filling compound 16, so that later opening is possible again.

Another embodiment is shown in Figs. 8-12. On the bottom of the vessel 1a Below the bottom cut 3 is a horizontal slide closure 33 arranged with paired slide rods 34 on at least one on the bottom of the vessel 1a attached thrust gear 35 is connected to the drive 36. A vertically rectangular floor tapping channel 37 is horizontally opposed by means of two adjustable pistons 38a, 38b made of refractory material (BN) can be closed. The cylindrical pistons 38a and 38b are guided in boron nitride sleeves 39 (see FIG. 9) and even made of boron nitride and by mechanical processing into each other fitted smoothly.

Each of the pistons 38a, 38b is equipped with its own drive 36. The drive 36 consists of a hydraulic drive 40 which (other than drawn) approx. 2500 mm is arranged outside the radiation area of the vessel 1. The connection between the housing 24 and a rotary drive 15 can also have a heat-protected cardan shaft that rotate the respective input pinion can.

9 and 10, the diameter of the pistons 38a, 38b is approximately 15-25% greater than the depth of the rectangular tapping channel 6. The tube 9 is in the area of the tapping channel 6. The pistons 38a, 38b move in opposite directions. In the tapping channel 6 is blocked in the closed position (FIG. 9). When moving together With a defined force, the metal melt in between becomes 2, such as the liquid steel, squeezed away. When moving apart the piston 38a, 38b, the tapping channel 6 is completely released. The one for every piston 38a, 38b own drive motor 36 consists of the hydraulic cylinder 40. Das The tapping channel 6 can be opened extremely quickly with a sinusoidal speed profile of rise and fall.

The closing of the pistons 38a, 38b also takes place in a first phase quickly, while in a second phase slower, with force control so as not to damage the pistons 38a, 38b by hard collision. This speed or force curve can in each case via the hydraulic cylinder 40 can be achieved with a servo valve control.

10 and 11 are rectangular tapping channels 6, pistons 38a, 38b, respectively with the length, round cylindrical boron nitride rods 41, a piston diameter, a channel depth and a channel width are shown.

According to FIG. 12, measures have been taken to freeze the molten metal 2 in Prevent area of pistons 38a, 38b. So that freezing in the closed Position of the boron nitride pistons 38a, 38b is avoided, takes place via inert gas flushing nozzles 42 a movement of the molten metal within the sink 43 2. In the open position of the pistons 38a, 38b (see FIG. 10) is in Refractory a heater 44 installed. The heater 44 is during the Tapping activates and prevents metal melt when closing the pistons 38a, 38b 2 on the opposite ends of the pistons 38a, 38b stiffens. This design therefore does not require a filling compound 16. The pistons 38a, 38b are in their closed position (see FIG. 11) by the one above Metal melt 2 is heated sufficiently so that there is no risk of blocking of the tapping channel 6 through solidified melt 2. Before the final one When the pistons 38a, 38b are closed, a middle position is reached. The outflowing Metal melt 2 heats up the end regions of the pistons 38a, 38b. This Heating brings the pistons 38a, 38b made of boron nitride to approximately melting temperature the molten metal 2. When the pistons are then moved together 38a, 38b a sticking of solidified metal melt 2 is avoided.

LIST OF REFERENCE NUMBERS

1

metallurgical vessel

1a

vessel bottom

2

molten metal

3

bottom tap

4

vertical axis position

4a

Abstichkanalachse

5

vertical course

6

tapping channel

6a

Abstichkanaldurchmesser

7

Abstichkanalrohrwand

8th

Abstichkanalabzweig

8a

Abstichkanalabzweigöffnung

9

Tube (from BN)

9a

diameter

9b

Flange, top

9c

Flange, bottom

10

control plug

10a

conical top

10b

section near the vessel bottom

11

closed position

12

lower opening position

13

bottom block

14

linear actuator

15

rotary drive

16

filling compound

17

Drive rotary motor

18

gear transmission

19

screw

20

spindle nut

21

T-slot

22

gear

23

gear

23a

wave

24

casing

25

planetary gear

26

drive motor

27

channel

28

transport means

28a

Auger

29

arcuate tapping tube

30

axis

31

vertical tapping tube

32

piston area

33

slide closure

34

slide rod

35

sliding gear

36

drive

37

rectangular floor tapping channel

38a

piston

38b

piston

39

Boron nitride sleeve

40

hydraulic cylinders

41

Boron nitride rods

42

Inert gas purge

43

porous plugs

44

heater

Claims (10)

Metallurgical vessel, in particular an electric arc furnace, which is in a vertical vessel position when tapping the molten metal and has a bottom cut,
characterized in that from the vertical course (5) of one or more tapping channels (6) in the tapping tube wall (7) in each case a tapping tap branch (8) obliquely downward to the tapping channel axis (4a) and then approximately vertically downward and that one on the Tapping channel axis (4a) control plug (10) guided in a tube (9) from an upper, on the vessel bottom (1a) in a closed position (11) sealing by positive locking, in which the lateral tapping channel branch opening (8a) is also closed, into a lower opening position ( 12) is adjustable, in which the control plug (10) clears the lateral tap channel branch opening (8a) to the tap channel (6). Metallurgical vessel according to claim 1,
characterized in that the pipe (9) larger in diameter (9a) than the tapping channel diameter (6a) for guiding the control plug (10) is embedded in a base block (13) made of refractory material attached to the bottom of the vessel (1a) and in that the base block ( 13) a linear actuator (14) and / or a rotary actuator (15) for the control plug (10) is mounted and the linear actuator (14) and the rotary actuator (15) are connected in terms of drive to the control plug (10). Metallurgical vessel according to one of claims 1 or 2,
characterized in that tapping channels (6) arranged in pairs in mirror images, each with a thrust drive (14) and a rotary drive (15), are provided on the vessel bottom (1a). Metallurgical vessel according to one of claims 1 to 3,
characterized in that a portion (10b) of the control plug (10) near the bottom of the vessel is hollow and can be filled with filler material (16) which is conveyed through a lateral channel (27) in the control plug (10) and in the base block (13) by means of a transport device (28) for the filling compound (16) in the closed position (11) of the control plug (10). Metallurgical vessel according to one of claims 1 to 4,
characterized in that the tapping channel (6) in the bottom block (13) runs straight and an arcuate tapping tube (29) is connected outside the bottom block (13), the axis (30) of which extends perpendicularly, or in that the tapping channel (6) in the bottom block (13 ) is curved and is followed by a tapping tube (31) running perpendicularly outside the base block (13). Metallurgical vessel according to one of claims 1 to 5,
characterized in that the drives (14; 15) for the control plug (10) each consist of either a gear transmission (18) which is heat-tightly enclosed in a housing (24) and connected via a drive train to a remotely located drive rotary motor (17) or is formed from a hydraulic motor (17; 26) which is arranged outside the radiation area of the vessel (1) and interacts with a piston surface (32) of the control plug (10) via a hydraulic line. Metallurgical vessel according to one of claims 1 to 6,
characterized in that the control plug (10) and the pipe (9) guiding it are each made of boron nitride or of a poorly wetting ceramic. Metallurgical vessel, in particular electric arc furnace, which is in the vertical vessel position when the molten metal is tapped and has a central bottom tapping,
characterized in that a horizontally located slide closure (33) is arranged on the bottom of the vessel (1a) below the bottom cut-off (3), which has paired slide rods (34) on at least one thrust gear (35) fastened to the bottom of the vessel (1a) with a drive motor (36 ) is connected and that a vertically rectangular floor tapping channel (37) can be closed by means of two pistons (38a; 38b) made of refractory material that can be adjusted horizontally in opposite directions and cover the rectangular floor tapping channel (37). Metallurgical vessel according to claim 8,
characterized in that the cylindrical pistons (38a; 38b) are guided in boron nitride sleeves (39) and are made of boron nitride. Metallurgical vessel according to one of claims 8 or 9,
characterized in that each piston (38a; 38b) has its own drive (36) which consists of a hydraulic cylinder (40) which is arranged outside the radiation area of the vessel (1).

Images