EP1391523A1 - Twin-furnaces unit for steel production - Google Patents

Abstract

Double oven arrangement has a tilting stage (29) arranged between two tilting oven stages (3) with a tilting, lifting and lowering electrode support device (16) formed on the tilting stage. The tilting stage can be tilted depending on the tilting movement of an oven stage for an oven vessel (4).

Description

The invention relates to a double furnace system for the production of steel materials through alternate charging of ferrous feed materials, oxygen inflation and arc melting using furnace A and a furnace B, which are each arranged on a tiltable furnace platform and with a swivel column arranged between furnaces A and B, on which one Liftable and lowerable electrode support device is attached and with a Swiveling device for at least one oxygen inflation lance.

Such a double electric arc furnace system is known from DE 44 34 369 and known from EP 0 717 115 B1. It is assumed that the two Furnace vessels are each arranged on a separate tilting platform. Between These two tilting platforms have a swiveling, lifting collar on the fixed oven platform lowerable electrode support device provided. This can be done alternately the scrap is melted in two furnace vessels. During that in a furnace vessel using the swiveling, lifting and lowering electrode support arms electrical energy is introduced into the melt on Second racking the rack and scrap for the next melt be introduced. In the system known from DE 44 34 369 is both Furnaces assigned a common non-tilting lance device.

In a so-called CONARC double furnace system (CONARC is a registered trademark from SMS Demag AG) can be used in the first Vessel for melting in the second vessel an oxygen lance, e.g. in shape a top lance.

In this known arrangement, it has been found that the Electrode support not at the same time as the respective tilting platform and can be tilted to the relevant furnace vessel. Provided the electrodes are used is also useful in a tilted position of the furnace vessel, it is missing on the necessary conditions. In general, the electrode feedthrough must have an oversized opening. It should also be noted that the Passing the electrodes through the furnace cover as little as possible requires. A small route is generally planned by planning Roll and curve weighing achieved. The use of such cradles is however with high technical effort. There are also large forces on the piston-cylinder unit when tilting the bricked and charged furnace vessel on. Roller and curve cradles are also subject to high wear. The exchange of rollers and rails is also expensive and long Downtime associated with the production facility. With the help of all of these Measures, the achievable tilt angle is at most approx. ± 3 °.

There are still double furnace systems known, with the help of a lifting and Swivel the electrode support device to the furnace vessel to be tilted Attach. In addition, the lifting and swiveling mechanism makes it highly technical Effort required. This design has also proven to be very practical proven susceptible to failure.

The invention has for its object the use of electrodes on one To design a double furnace without any restrictions on the part of the furnace mechanics.

The stated object is achieved according to the invention in the double furnace system described at the beginning solved by the fact that between the two tiltable furnace stages a third tilting platform is provided on which the swiveling, lifting or lowering Electrode support device is arranged and that the third tilting platform in direct dependence of the tilting movements of one of the furnace platforms for a furnace vessel is tiltable. This means that even with a tilted furnace vessel the electrodes are worked undisturbed, which is particularly the case with the process steps operated using the CONARC method are of great advantage is. The use of such a third tilting platform is at least for a DCund AC double oven possible. There are special advantages for different Process steps such as pig iron charging, dephosphorization, slag reduction u. like.

One embodiment consists in that the third tilting platform with the pivotable, Liftable and lowerable electrode carrying device alternately with each can be locked to tilt the furnace platform. This creates absolutely dependent Tilting movements between the furnace platform of one furnace vessel and the third Tilt bed.

The invention can also be improved in that the third tilting platform with the swiveling, lifting or lowering electrode carrying device Tilt drive is assigned to a control device. This allows the respective furnace platform and the third tilting platform can be operated absolutely simultaneously.

For the above design, there is also the suggestion that the Control device of the own tilt drive formed from a synchronous device is that connectable to the control device of the respective furnace platform to be tilted is.

Another advantageous design is also created in that the Own tilt drive from a piston-cylinder unit arranged within the foundation is formed. The space required for this between the furnace stages has not previously been used for the furnace vessels.

Another measure to secure the different tipping processes is achieved in that with an existing connection of the synchronization device with the respective control device of a furnace platform to be tilted locked to the other control device for the other furnace stage is.

A further development of the invention provides that in each of the furnace A and B associated lid swivel device each integrates an oxygen lance is, the combination swivel device for lid and blowing lance on the tiltable Furnace stage is arranged.

Although an additional O ₂ lance with lance guide and O ₂ feed line must be provided for this layout of the system, the advantages lie in the fact that no separate swivel devices are required for the oxygen lances, but rather the lances are integrated into the existing cover swivel devices become. At the same time and this is a particular advantage, the O ₂ lances can be tilted together with the swiveling devices via the furnace platform together with the furnaces. This allows the furnace to tip over with the O ₂ lance retracted. In addition, the system is less susceptible to failure of an O ₂ lance, since operation in the other furnace can continue.

The system according to the invention with a tiltable electrode support device and tiltable cover pivoting devices with integrated oxygen lances is advantageously further developed by replacing the known complex cover lifting mechanism with a supporting arm construction with lifting mechanism. Specifically, in addition to the support arm for the oxygen lance, the cover pivoting device has at least one further support arm, preferably two support arms, for the furnace cover and the O ₂ lance cover. These support arms are arranged at one end on a swivel column. At the other end, which extends over the cover, hydraulic lifting cylinders are arranged, which are connected to the respective top of the cover. The lids can be placed on or removed from the respective furnace via these lifting cylinders. These lifting cylinders are distributed over the support arms.

The system is further developed by an advantageous exhaust system. From the basic idea, a common exhaust pipe pro now takes over Oven removes the hot gases and dusts in the melting and in the Blowing process. This exhaust pipe is constructed in several parts. A pipe part that immediately is arranged on the furnace cover, is releasably opposite as a pipe socket formed the rest of the exhaust pipe and together in the decoupled state pivotable with the furnace lid. When the furnace lid swings onto the furnace this pipe socket is flush with the rest of the exhaust pipe, the exhaust pipe connected to the pipe socket together with the Oven platform is tiltable. This has the advantage that in a less complex manner Way the oven vessel can be opened for charging and only a part of the Pipe elbow must be pivoted.

Overall, this results in a system that, compared to the prior art less expensive design of the lid lifting mechanism and the exhaust manifold lifting device shows that needs to be raised. Tipping through the The furnace platform is less expensive than tipping using a roller cradle. In addition, the cooling water supply to the furnace lid can be significantly more reliable and run more cheaply because of a convenient arrangement the cooling water pipes to the furnace cover is possible. The manufacturing cost the overall system are reduced overall, while at the same time operational safety and the flexibility of the system can be increased. Also the possibility improved to plan the system concept in existing halls.

In the drawing, embodiments of the invention are shown, the following are explained in more detail.

Fig. 1

einen Aufriss einer Doppelofen-Anlage,

Fig. 2

die zu Fig. 1 gehörende Draufsicht auf die Doppelofen-Anlage, mit einem vom Ofengefäß B weggeschwenkten Ofendeckel,

Fig. 3

die dritte Kippbühne in Normalstellung in der Seitenansicht,

Fig. 4

die dritte Kippbühne in der nach hinten gekippten Stellung,

Fig. 5

die dritte Kippbühne in einer nach vorne gekippten Stellung,

Fig. 6

eine zu Fig. 1 gehörende Draufsicht auf die Doppelofen-Anlage in einer anderen Betriebsposition und

Fig. 7

eine Draufsicht auf die Elektroden-Tragvorrichtung mit Nachsetzvorrichtung.

Show it:

Fig. 1

an elevation of a double furnace system,

Fig. 2

1 top view of the double furnace system, with a furnace lid pivoted away from the furnace vessel B,

Fig. 3

the third tilting platform in normal position in a side view,

Fig. 4

the third tilting platform in the tilted back position,

Fig. 5

the third tilting platform in a forward tilted position,

Fig. 6

a top view of Fig. 1 of the double furnace system in a different operating position and

Fig. 7

a plan view of the electrode support device with repositioning device.

On foundations 1 are an electric arc double furnace arrangement for a furnace A and a same furnace B by means of a base 2 a tiltable Furnace stage 3 for one furnace vessel 4 each with an furnace lid 5 arranged (see Fig. 1). Electrodes 6 are moved from an oven transformer 7 (see FIG. 2) via a high-current connection 8 by means of a transformer house wall 9 High current cables 10 supplied. The electrodes 6 can by means of a swivel column 11 can be pivoted over oven A or oven B.

For this purpose, the electrodes 6 are brought into an upper position shown in FIG. 1 by a lifting column 15 in the swivel column 11. During this time, this O ₂ lance 13a is located above the furnace B by means of a pivoting device 12 for the oxygen inflation lance 13a, which is also on the furnace stage 3.

The electrodes 6 are by means of the lifting column 15 with a column guide and Electrode support device 16 in height to regulate the energy supplied used. Then there are support arms 17 and 14 for an inner electrode cover 18 or a similar inner cover 21 for the oxygen inflation lances 13a and b provided. The inner electrode cover 18 can be adjusted in height by means of lifting cylinders 19 (see Fig. 2). There is also an electrode repositioning device 20 available. The inner electrode cover 18 is held by means of the support arms 17.

The exhaust pipe 23 connected to the tilting platform 3 is in the pivoted-in position Able to connect a stationary exhaust pipe 24 with an afterburning chamber 25. The exhaust gases are removed from the furnace B by means of an exhaust connector 26. (The furnace cover 21 is pivoted out in Fig. 2). The exhaust pipes 23, 24 and the Exhaust pipe 26 are connected to each other. Between the individual components are gaps that allow corresponding furnace movements. The gap between Tubes 23 and 24 are particularly manually adjustable. The gap between Tube 24 and the exhaust pipe 26 is adjustable by a sliding sleeve. about the change in the air gap becomes the amount extracted from the oven and the Pressure in the furnace vessel influences and that for the afterburning (and cooling) necessary amount of wrong air sucked in. The blow lance inner cover 21 can can be adjusted in height by means of a lifting cylinder 33.

A third tilting platform 29 is arranged between the furnace stages 3 of the furnaces A and B, on which the swivel stage 11 and the electrode repositioning device 20 are located. Located on the third tilting platform 29 the pivoting column 11, the pivotable, lifting and lowering electrode support device 16 at the other end to the electrode repositioning device 20. This third tilting platform 29 is alternately according to a first embodiment locked with the furnace platform 3 to be tilted in each case. A second embodiment provides a separate tilt drive 30 for the third tilting platform 29 (cf. FIG. 3), which in the exemplary embodiment consists of a piston-cylinder unit 31 which is inside of the foundation 1 is stored.

The third tilting platform 29 is in the normal position according to FIG. 3, in FIG. 4 in forward inclined position and in Fig. 5 in one of the respective oven and Charge position dependent, backward inclined position.

The arrangement of the respective pivoting devices 12 for the furnace cover 5 and the O ₂ inner cover 21 with integrated oxygen lance 13a, b is clear from the two FIGS. 2 and 6. In addition to the function of pivoting the cover, the combination swivel device 12 also has the function of bringing the lance for blowing oxygen 13a, b towards the center of the furnace. The O ₂ lance system is not on the fixed furnace platform, but is integrated in the revolving tower for pivoting the lid, which is arranged on the tiltable furnace platform 3. In detail, the swivel device 12 consists of an inner central support arm 27, at the tip of which an O ₂ lance 13a, b is attached, which is supplied by the support arm via an oxygen line. The O ₂ lance 13a, b is carried by the support arm 27, which is connected to a guide column and is guided in guide rollers. The lifting movement of support arm 27 and O ₂ lance 13a, b takes place via a hydraulic cylinder installed in the guide column.

The pivoting device 12 further comprises two support arms 14 of the cover structure, which extend over the furnace cover 5, first parallel to the central lance support arm 27, and then, when they have reached the edge of the O ₂ inner cover 21, V - to diverge. In this way, the support arms 14 extend both over the furnace cover and over the O ₂ lance inner cover.

The support arms 27 and 14 are by means of a rotating column with a roller bearing pivoted, the support arm for the lance 27 and the structure for the lids are pivoted together.

Compared to conventional systems, the cable winch control of the oxygen lance is replaced by control using a support arm, guide rollers and hydraulic cylinders. By assigning the lances 13a, b to the swiveling devices 12, the furnace stage becomes free on the door side. This improves the view from the control center to the furnace system and to the electrode repositioning device 20. The scrap basket passage and the vessel transport through the 02 lance system are not obstructed. When laying out the hall width when building a new system, the pivoting of the O ₂ lance should not be taken into account.

Lifting cylinders 22, 33 are arranged along the support arms 14, namely three for the furnace cover 5 and four for the lance inner cover 21. They are each corresponding the lid edge arranged. The lid or lids will be pivoted over the furnace and then over the lifting cylinders 22, 33 by the movement move the respective piston rod down into a closed position. The lifting rod of the lifting cylinder 22 for the furnace cover 5 is in the lowered Position decoupled from the lid 5, so that a pivoting of the pivoting device 12 with the support arm 27 and the lance 13 and the support arm 28 with Lance lid 21 in the case of an oven lid 5 resting on the oven vessel 4 is possible.

2 and 6 different process states of the Conarc process, in particular for the production of carbon steels and stainless steels, such as stainless steel, are shown. According to FIG. 6, the blowing process takes place in furnace A, while the melting process with inserted electrodes 6 takes place simultaneously in furnace B. The pivoting device 12 is pivoted over the furnace A for the blowing process. With it or the supporting structure (14) for the cover 5 or the supporting arm 27 for the lance 13b, the furnace cover 5 with the flue gas connector 26, the O ₂ lance inner cover 21 and the oxygen lance 13b are pivoted into the middle of the furnace.

During the melting process, the furnace cover 5 with the flue gas connection is also located 26 on the furnace vessel 4 (in FIG. 6 furnace B). With the swivel device 12, the lance 13a and the lance inner cover 21 are pivoted out. The electrode arm is pivoted to the middle of oven B.

The electrode swiveling device also consists of a support arm construction together, with the inner electrode cover 18 over along the Support arms 17 positioned lifting cylinder 19 can be arranged in the lid heart. Within the support arm construction, which is essentially rectangular three electrode support arms 16 are formed, at the ends of which the electrodes 6 are attached.

The state of the furnace A shown in FIG. 2 corresponds to the state of the furnace B in FIG. 6. The furnace B in FIG. 2 shows the state of the fully open furnace. By means of the pivoting device 12 or the supporting structure, both the furnace cover 5 - with the flue gas connector 26 attached to it and the O ₂ lance inner cover 21 are pivoted together with the lance 13a.

For repositioning the electrodes 6 due to the erosion of the electrode tips need to be moved down a bit, the electrodes 6 with the pivoting column 11 pivoted onto a central repositioning device 20 (see FIG. 7), which is in the system shown between the two furnaces A and B located.

The use of the third tilting platform 29 is possible with DC or AC double ovens. However, the construction is particularly advantageous in a CONARC double furnace system, in which different process steps, such as pig iron charging, dephosphorization, Slag reduction u. Like. Be carried out to apply.

LIST OF REFERENCE NUMBERS

A

Oven A

B

Oven B

1

foundations

2

substructure

3

tiltable furnace platform or tilting frame

4

furnace vessel

5

furnace cover

6

electrodes

7

furnace transformer

8th

High current connection

9

Transformer house wall (transformer house wall)

10

High current cables or high current cables

11

Swivel column for electrode support arms and electrode inner cover

12

Swivel device for the blowing lance, the furnace lid and the lance inner lid

13

Blow lances (a + b)

14

Support arms for the furnace lid and the lance inner lid

15

Lifting column for the electrode support arms

16

Electrode support device, electrode support arms

17

Support arms for the inner electrode cover

18

Electrode inner cover

19

Lift cylinder for the inner electrode cover

20

Electrode slipping device

21

furnace cover

22

Lift cylinder for the furnace lid

23

Exhaust pipe on the tipping frame

24

stationary exhaust pipe or exhaust pipe to the afterburner

25

afterburner chamber

26

flue outlet

27

Support arm for the blowing lance

28

Support arm for the lance inner cover

29

third tilting platform or third tilting frame

30

own tilt drive or own drive to the third tilt frame

31

Piston-cylinder unit or tilt cylinder

32

Lifting column for the blow arm support arm

33

Lift cylinder for the inner lance cover

Claims (10)

Double furnace system for the production of steel materials by alternately charging iron-containing feedstocks, oxygen inflation and arc melting, each by means of furnace A and furnace B, which are each arranged on a tiltable furnace platform (3) and with one between furnaces A and B. arranged swivel column (11), on which a liftable and lowerable electrode support device (16) is fastened, and with a swivel device for at least one oxygen lance,
characterized in that a third tilting platform (29) is provided between the two tiltable furnace platforms (3), on which the pivotable, liftable and lowerable electrode support device (16) is arranged and that the third tilting platform (29) is directly dependent on the Tilting movements of one of the furnace platforms (3) for a furnace vessel (4) can be tilted. Double furnace system according to claim 1,
characterized in that the third tilting platform (29) with the pivotable, lifting or lowering electrode support device (16) can be locked alternately with the furnace platform (3) to be tilted in each case. Double furnace system according to claim 1,
characterized in that the third tilting platform (29) with the pivotable, liftable or lowerable electrode support device (16) is assigned its own tilting drive (30) with a control device. Double furnace system according to one of claims 1 and 3,
characterized in that the control device of the own tilting drive (30) is formed from a synchronizing device which can be connected to the control device of the respective furnace stage (3) to be tilted. Double furnace system according to one of claims 3 or 4,
characterized in that the own tilt drive (30) is formed from a piston-cylinder unit (31) arranged within the foundation (1). Double furnace system according to one of claims 3, 4 or 5,
characterized in that when the synchronization device is connected to the respective control device of a furnace platform (3) to be tilted, a connection to the other control device for the other furnace platform (3) is blocked. Double furnace system according to one of claims 1 to 6,
marked by
a cover pivoting device for each furnace A and B, in each of which the pivoting device for the oxygen lance (13a, 13b) is integrated, the common pivoting device (12) being arranged on the tiltable furnace platform (3). Double furnace system according to claim 7,
characterized in that the common pivoting device (12) has a support structure for the furnace cover (5) and the O ₂ lance cover (21) and a support arm (27) integrated therein for the oxygen lance (13a, b) and
that the electrode support device (16) has a support structure for the electrodes (6) and for the electrode inner cover (18). Double furnace system according to claim 8,
characterized in that the cover structure and the electrode structure have lifting cylinders (19, 22, 32) which correspond to the geometric dimensions of the furnace cover (5), the O ₂ lance cover (21) and the inner electrode cover (18) Over which the supporting arms (14, 17) forming the structure are arranged and over which the respective covers can be moved from an elevated swivel position into a lowered furnace-closed position and from which the covers can be uncoupled. Double furnace system according to one of claims 1 to 9,
characterized in that each furnace (A, B) is assigned an exhaust pipe, through which the exhaust gas is led away from the furnace during the melting process or during the fresh process, and in that the exhaust pipe is constructed in several parts,
wherein an exhaust pipe (23) connected to the tilting platform (3) can be connected to a post-combustion chamber (25) via a fixed exhaust pipe (24) when the position is pivoted in, and an exhaust pipe (26) which is arranged on the furnace cover (5), is detachable from the exhaust pipe (23) and can be pivoted together with the furnace cover (5) in the decoupled state.

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