EP2855713B1 - Method for opening and closing a tapping opening of a metallurgical melting vessel, and metallurgical melting vessel - Google Patents

Description

The invention relates to a method for opening and closing a tapping opening of a metallurgical melting vessel, in particular an electric arc furnace, in the bottom region of a wall portion is arranged with an opening, wherein below the opening, a device for opening and closing the tapping opening is arranged.

Generic methods are known in the art. The WO 2005/024069 A2 discloses a tapping apparatus for a melting vessel. On a tapping channel here a nozzle replaceable placed. The nozzle is positioned by means of a nozzle changer and replaced by a new nozzle after each tapping or after two or more taps. The device is designed relatively expensive.

The EP 1 172 162 A1 shows a solution in which two vertically superimposed linear slide are provided in the tapping opening. By appropriate control of the slide, a free-flowing filling compound is introduced into the intermediate space between the slides in order to close the tapping opening again after tapping.

In the WO 2011/009579 A1 Another solution is described in which a sealing and filling pipe, a container with filling compound, an opening and closing device and a hoist are used.

Other special solutions, in particular for closing the tapping opening after tapping show the EP 0 624 769 B1 , the EP 1 203 920 A1 and the DE 32 30 646 C1 , Other similar solutions show the WO 97/31736 A1 , the WO 98/15374 A1 , the JP 2000 033465 A and the JP H10 286658 A ,

A disadvantage of all previously known solutions that sometimes a very high device complexity has to be driven to produce continuity in the tapping process. The tapping opening and in particular the optionally arranged in this nozzle are subject to a relatively high wear, so that the tapping process due to wear changes over time. If previously known alternating nozzles are provided for this purpose, the devices for placing the nozzles are expensive.

Another problem is that a high level of security must be ensured, ie. H. the proper functioning of the components during tapping (safety against tapping runners).

The invention is therefore based on the object to provide a method of the type mentioned above and a melt-metallurgical vessel, with which it is possible to carry out the tapping cost and safely. The device used should be simple in design. The same process conditions should be guaranteed for every tapping. The tapping should be carried out in a safe manner, so that tapping can be safely avoided.

The solution of this object by the invention according to the method is characterized in that below the opening of Wandungsabschnitts a device for moving block elements is arranged in one direction, which is perpendicular to the surface normal of the Wandungsabschnitts in the region of the opening (ie in the tangential direction of the Wandungsabschnitt or in the plane of the Wandungsabschnitts), wherein the device holds the block elements on the Wandungsabschnitt so that they rest sealingly on the wall portion, wherein for closing the tap opening a block element of the device below the opening is pushed, which is free of passage openings, and wherein for opening the tap opening a block element is pushed by the device under the opening, which has at least one passage opening, so that can drain through the passage opening in the block element liquid metal from the melting vessel, wherein for each closing of the tap opening a new block element is used without passage opening and wherein for each opening of the tap opening, a new block element is used with passage opening.

Preferably, it is provided that the block elements are translationally displaced by the device in the direction which is perpendicular to the surface normal of the wall portion in the region of the opening.

The passage opening in the block element is vorzugswiese at least partially filled with slider sand prior to placement under the opening.

A corresponding metallurgical melting vessel is characterized in that the device has a guide for displacing block elements in one direction, which is perpendicular to the surface normal of the wall section in the region of the opening, and at least one actuator for displacing the block elements.

The guide is preferably designed to hold the block elements sealingly on the wall section.

The guide is preferably a linear guide. It is also conceivable, however, an arcuate guide on which the block elements can be performed rotatory.

The actuator is preferably a hydraulic piston-cylinder system.

The block elements are preferably cuboid.

Thus, the invention proposal is based on alternating nozzles and shut-off blocks, with which the tapping can be opened and closed automatically. Advantageously, so far no wear occurs on the nozzle, which would change the tapping process over time. Furthermore, a high degree of security is given.

Preferably, a plugging machine is used for filling the pusher sand through the alumina plug.

The proposed procedure is preferably used on fixed meltdown units. However, it is not excluded that the proposal according to the invention is also used on non-fixed aggregates.

The preferred application of the invention are smelting units such as electric arc furnaces (SAF - Submerged Arc Furnace, so-called Contiarc ovens).

Fig. 1

schematisch die Seitenansicht eines Elektrolichtbogenofens, wobei eine Abstichöffnung im Bodenbereich des Ofens verschlossen ist,

Fig. 2

schematisch die Seitenansicht des Elektrolichtbogenofens nach Fig. 1, wobei die Abstichöffnung jetzt für das Abfließen von Schmelze geöffnet ist,

Fig. 3

schematisch die Seitenansicht des Elektrolichtbogenofens nach Fig. 1, wobei die Abstichöffnung jetzt wieder verschlossen ist, und

Fig. 4

eine vergrößerte Darstellung des Bereichs der Abstichöffnung im Status gemäß Fig. 2, das heißt mit geöffneter Abstichöffnung.

In the drawing, an embodiment of the invention is shown. Show it:

Fig. 1

1 is a schematic side view of an electric arc furnace, with a tapping opening being closed in the bottom region of the furnace;

Fig. 2

schematically the side view of the electric arc furnace after Fig. 1 with the tapping opening now open for the melt flow,

Fig. 3

schematically the side view of the electric arc furnace after Fig. 1 , The tap hole is now closed again, and

Fig. 4

an enlarged view of the area of the tap opening in the status according to Fig. 2 that is with the tap open.

In Fig. 1 a metallurgical melting vessel 2 is sketched in the form of electric arc furnace. In vessel 2 scrap is liquefied by 12 energy is entered in a known manner by means of electrodes. Accordingly, melt 16 is formed, which occupies a certain level in the vessel 2. The vessel has a wall with a bottom region 3, in which a tapping opening 1 is present, can be discharged via the melt 16 from the vessel 2. For this purpose, the tapping opening 1 in a defined manner to open and close again. In order to be able to accomplish this in a reproducible and safe manner, an opening 5 is present in a wall section 4 of the bottom area 3, which opening can be opened or closed from below. For this purpose, a device 6 is provided, which will be described in more detail below.

So that a certain residual sump is always retained in the vessel 2, a refractory protective tube 15 is arranged above the opening 5. Incidentally, a filling tube 13 for slider sand is present, at the lower end of a bell 14 is arranged for slag-free tapping.

The opening and closing of the opening 5 in the bottom region 4 of the vessel takes place through the use of block elements 7, 8, which have a cuboid shape. A first type of block elements 7 consists of a refractory body, which is free of channels. However, a second type of block elements 8 is also provided which have a passage opening 9 and act as an outlet nozzle for liquid metal.

Said block elements 7, 8 are selectively displaced by the device 6, namely in a direction T which is perpendicular to the surface normal of the wall section 4 in the region of the opening 5, d. H. There is a shift in the plane defined by the bottom of the wall portion 4 of the vessel; it is therefore a tangential displacement along the surface of the wall region 4.

In Fig. 1 It can be seen that a block element 7 has been pushed by an actuator 11 of the device 6 directly under the opening 5, so that the vessel 2 is sealed and consequently no melt 16 can escape. In the in Fig. 1 shown situation of the vessel 2, scrap is melted in the vessel and thus generates a certain level of melt 16 in the vessel 2. The opening 5 in the bottom region 3 is in this case filled with slider sand.

In Fig. 2 is shown that the vessel 2 is open for tapping down, ie, the opening 5 is released, so that melt 16 can flow out of the vessel 2. For this purpose, a block element 8 has been pushed with the passage opening 9 by the actuator 11 under the opening 5, so that now melt 16 can flow out of the vessel 2.

In Fig. 2 is indicated by an arrow that the previously inserted block element 7 was ejected; it is disposed of.

After the desired amount of melt has drained, the vessel 2 is closed again; this is in Fig. 3 indicated. By the actuator 11, the next block element 7 - now again without a passage opening 9 - has been pushed under the opening 5, whereby the latter is sealed. By means of the filling tube 13, slider sand is again filled into the opening 5 before recharging the vessel 2.

In Fig. 3 is again indicated by an arrow that used block elements 7, 8 - now the block element 8 - are ejected and disposed of.

In Fig. 4 For details on the structure of the device 6 can be seen. It can be seen that the block elements 7, 8 are displaced on a (linear) guide 10 in the direction T, to which end the piston-cylinder system 11 serves. The block elements 7, 8 must bear sealingly against the underside of the wall section 4 in order to prevent the melt 16 from escaping from the vessel 2. For this purpose, what is not shown in detail, be provided that an upward force on the block elements 7, 8 is exerted by the linear guide 10, so that these elements lie cleanly against the underside of the wall section 4.

• Im Bodenbereich 3 des Einschmelzaggregats 2 befindet sich bei sog. Erkerabstichsystemen die Bodenhülse (die die Öffnung 5 aufweist), über der das feuerfeste Schutzrohr 15 angeordnet ist. Unterhalb der Bodenhülse befindet sich ein Schiebersystem (Vorrichtung 6) mit Düsenblöcken 7 und 8. Zum Öffnen des Abstichs wird mittels des hydraulischen Schiebers 11 ein Block 8 mit einer Düsenöffnung (Durchtrittsöffnung) 9 unter die Bodenhülse geschoben, die über den Stopfen 13 mit Schiebersand gefüllt ist.

The invention can therefore be summarized or characterized as follows:

• In the bottom area 3 of the smelting unit 2, in the case of so-called bay window stitching systems, there is the ground socket (which has the opening 5), above which the refractory protective tube 15 is arranged. Below the bottom sleeve there is a slide system (device 6) with nozzle blocks 7 and 8. To open the tap, a block 8 with a nozzle opening (passage opening) 9 is pushed by the hydraulic slide 11 under the bottom sleeve, which is filled via the plug 13 with slider sand is.

After expiration of the slider sand through the passage opening 9 in the nozzle block 8, the melt is tapped. Through the protective tube 15 above the bottom sleeve, a residual sump always remains in the vessel 2.

After tapping the melt, a solid block 7 is placed without opening under the bottom sleeve and the sleeve filled with slider sand by means of the filling tube 13. Immediately thereafter, the batching can be started to start the meltdown cycle.

LIST OF REFERENCE NUMBERS

1

tapping opening

2

metallurgical melting vessel (electric arc furnace)

3

floor area

4

wall section

5

opening

6

Device for moving block elements

7

Block element (without passage opening)

8th

Block element (with passage opening)

9

Through opening

10

guide

11

Actuator (piston-cylinder system)

12

electrodes

13

Filling tube for pusher sand (plug)

14

Bell for slag-free tapping

15

thermowell

16

melt

T

direction

Claims (3)

1. Method of opening and closing a tap opening (1) of a metallurgical melt vessel (2), particularly an electric arc furnace, in the base region (3) of which a wall section (4) with an opening (5) is arranged, wherein arranged below the opening (5) is a device (6) for displacement by block elements (7, 8) in a direction (T) perpendicular to the surface normal of the wall section (4) in the region of the opening (5), wherein the device (6) so retains the block elements (7, 8) at the wall section (4) that these sealingly bear against the wall section (4),
   wherein for closing the tap opening (1) a block element (7) free of passage openings is displaced by the device (6) under the opening (5) and
   wherein for opening the tap opening (1) a block element (8) having at least one passage opening (9) is displaced by the device (6) under the opening (5) so that liquid metal can run out of the melt vessel (2) through the passage opening (9) in the block element (8),
   wherein a new block element (7) without a passage opening is used for each closing of the tap opening (1) and
   wherein a new block element (8) with a passage opening (9) is used for each opening of the tap opening (1).
2. Method according to claim 1, characterised in that the block elements (7, 8) are displaced by the device (6) translationally in the direction (T) perpendicular to the surface normal of the wall section (4) in the region of the opening (5).
3. Method according to claim 1 or 2, characterised in that the passage opening (9) in the block element (8) is at least partly filled with filler sand prior to being placed under the opening (5).

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