EP1287723B1 - Method and device for changing the electrodes of an electrically operated metallurgical vessel, especially an arc furnace - Google Patents

Abstract

The invention relates to a method for changing the electrodes (3) of an electrically operated metallurgical vessel (1), especially an arc furnace, whereby a unit comprising contact electrodes with electrical connectors, coolant connectors and thermocouple connectors arranged on a base plate (10) is replaced with a new unit. In order to achieve this, the used unit (3) is detached from the bottom of the vessel (1a), lowered onto a positioned changeover carriage (5) or a changeover adaptor and taken away. The new unit (3) which is transported on the changeover carriage (5) or changeover adaptor is inserted into and secured to the bottom of the tank (1a) from below in a self-centering manner.

Description

The invention relates to a method and a device for changing the electrodes on an electrically operated metallurgical vessel, in particular on one Arc furnace, by exchanging a unit consisting of on a base plate arranged contact electrodes with electrical connections, coolant and Thermocouple connections, against a new unit.

Metallurgical vessels of this type, in particular arc furnaces or shaft furnaces, are equipped with a metallic electrode attached to the jacket of the bottom of the vessel, on one side, e.g. from below, protrudes through the bottom of the vessel into the oven and connected to an electrical supply line on the outer side and is also cooled from this side.

The contact electrodes in the arc furnace are subject to one in relation to the furnace lining leading wear. Because the replacement of individual electrode rods requires a relatively large amount of time and work, one has started to replace all electrodes together.

From EP 0 449 258 A3 the method described at the outset is known a conical masonry block with the contact electrodes and electrical Connections, coolant and thermocouple connections based. The used one After detaching from the bottom of the furnace, the unit is placed on a change car lowered and transported away. The new unit is transported to the change car and is said to be due to the conical shape of the FF block in the conical Center the bottom opening of the masonry from below. It is however, the conical shape of the masonry block and the opening in in the form that centering, i.e. a process of changing cars can take place. The conical annular gap must also be sealed.

A device for changing the electrode unit is also known (EP 0 219 650 A1). The known procedure is based on a construction in which the electrodes, including the stamping out, are preassembled on a base plate and are lowered into the furnace bottom from above by means of a crane on an eyelet. After the centering has to be carried out in particular, the remaining annular gap between the electrode unit and the furnace bottom is filled with ramming compound. The pre-assembled eyelet is dissolved in the melt with the first melting process. The electrode unit on the base plate is broken out in such a way that hydraulic cylinders are arranged beneath the electrode arrangement on claws, which break it out of the furnace floor via the base plate of the electrode arrangement. The hydraulic cylinders raise the electrodes to such an extent that a crane with appropriate grippers can pull the electrodes upwards.
This procedure is disadvantageous in that the furnace base must be reinserted, ie stamped, when the new electrodes are inserted. Disadvantages of this procedure and of the device itself are primarily the complex work by means of a crane, the inaccurate centering in the furnace floor and the complex and expensive device for breaking out the electrode unit, which must be provided separately on each furnace vessel. The imprecise centering of the electrodes has a not inconsiderable influence on the position of the magnetic fields and the associated deflection of the arc.

Another known construction provides (DE 40 26 897 A1), a divided electrode to be applied in a wear part to be replaced and one in the ground Functional connector for electrical power and coolant supply is divided. This split electrode is connected on the inside by means of clamping screws. The lower part of the electrodes remains in the furnace bottom, the upper one Wear part after lifting the tensioning screws by a crane upwards is lifted out of the oven. Prerequisite for this type of electrode changing device are adequate space above the oven to be with a crane change the spent electrode. This space are not available for all furnace types. In some arc furnaces, e.g. of type Contiarc, the electrodes can only be changed due to the space available done below. This design can e.g. also for the combination of an oven with a preheater system that is placed next to or on the stove, be applied. Because of different attachments, the space available be limited above the vessel in other ovens, so that an expansion after below is advantageous

The invention has for its object without the expansion of the electrode units by means of a crane and without one tied to each oven vessel Assignment of hydraulic cylinders to get by, better centering to reach the electrode unit during installation and less repair work to have to carry out on the furnace floor after a change.

The object is achieved according to the invention on the basis of a method solved, in which the used unit after loosening from the bottom of the vessel a positioned change car or a change adapter lowered and transported away and where the new one, on a change car or on a Removable adapter inserted unit inserted into the bottom of the vessel from below and is attached, the change car or the change adapter with in pairs arranged hydraulic cylinders hydraulically connected in the positioned position and the piston rods self-centering laterally in coupling devices be retracted to the bottom of the vessel and locked. This makes a crane for It is no longer necessary to change the anode above the furnace vessel and one furnace vessel no longer needs to be equipped with hydraulic cylinders. Besides, can an automatic centering of the new unit take place and it is only necessary between the refractory lining and the used electrode unit re-insert brickwork removed during removal.

Another step of the procedure is that one with the hydraulic cylinders connected change adapter under the base plate of the unit with the contact electrodes lifted and a connection between the removable adapter and the Base plate is made. The used unit can already be used as a change car aligned and centered.

Transferring the used unit from the furnace vessel to the change adapter of the change car takes place simply by the fact that after the concern of the unit the Contact electrodes on the interchangeable adapter between the unit of contact electrodes and the connecting bolts located on the bottom of the vessel are loosened. The loosening can be supported by hydraulic cylinders if necessary.

The contact electrode unit is finally brought onto the change carriage by the wax adapter connected to the hydraulic cylinders due to its own weight the unit with the contact electrodes lowered via the hydraulic cylinders become.

The installation is carried out in such a way that the change carriage or the change adapter is positioned under the vessel and four hydraulic cylinders with the vessel bottom get connected. When lifting the interchangeable adapter with the new unit it centers itself and is lifted into the furnace vessel with the hydraulic cylinders and attached there.

After lowering the interchangeable adapter and releasing the coupling device on the bottom of the vessel and retracting the hydraulic cylinders are the change car or the Removable adapter removed.

The device for changing the electrodes in an electrically operated metallurgical Vessel, especially in an arc furnace, solves the task Avoid crane, hydraulic cylinders permanently present on every furnace vessel avoid and better center the unit to be replaced by on a An interchangeable adapter with a mobile interchangeable trolley centrally under the bottom of the vessel hydraulic cylinders provided in pairs can be raised and lowered and by a coupling device is provided on the piston rods of each can be connected self-centering with a counter coupling on the bottom of the vessel. The Change trolley or the change adapter can be used for several furnace vessels be so that only a single assembly with hydraulic cylinders is required is.

The fact that the coupling device and the associated counter-coupling each can be locked and unlocked, the hydraulic cylinders can each be raised the platform and to lower the load safely

The change carriage or the change adapter then represents a compact unit, if, according to further features, the interchangeable adapter has extension arms in pairs, in each of which a hydraulic cylinder is held.

A precisely positioned transfer position is also achieved in that the base plate, on which the unit of contact electrodes rests, has further centering means, which when lowering through the change adapter of the change car into the Intervene in the wagon frame of the change car. This also affects the location of the Interchangeable adapter on the interchangeable car itself.

The positioning between the base plate and the interchangeable adapter is advantageous thereby precisely stipulated that on the change adapter of the change car Centering means for receiving means corresponding in the base plate of the unit are provided, which form a releasable connection in the closed position.

In the drawing, an embodiment of the invention is shown, the following is explained in more detail.

Fig. 1

einen senkrechten Schnitt durch den Bodenbereich eines Elektro-Lichtbogenofens mit einem Wechselwagen in Position für den Ausbau einer verbrauchten Elektroden-Einheit,

Fig. 2

denselben Schnitt mit im Bodenbereich des Elektro-Lichtbogenofens gekuppelten Hydraulikkolben,

Fig. 3

den Schnitt mit an den Gefäßboden angesetztem und zentriertem Wechseladapter,

Fig. 4

den Schnitt mit eingebauten Verbindungsbolzen vor dem Ausbau der verbrauchten Elektroden-Einheit,

Fig. 5

den Schnitt mit in Einbaustellung positioniertem Wechselwagen, auf dem eine neue Einheit der Elektroden zentriert ist,

Fig. 6

den Schnitt mit im Gefäßbodenbereich eingekuppelten Hydraulikkolben,

Fig. 7

den Schnitt mit auf dem Wechsel adapter zentrierter Basisplatte nach dem Einbau der Verbindungsbolzen und

Fig. 8

den Schnitt mit der eingebauten neuen Einheit und dem ausfahrbereiten Wechselwagen.

Show it:

Fig. 1

a vertical section through the floor area of an electric arc furnace with a change carriage in position for the removal of a used electrode unit,

Fig. 2

same cut with hydraulic pistons coupled in the base area of the electric arc furnace,

Fig. 3

the cut with the exchangeable adapter attached and centered on the bottom of the vessel,

Fig. 4

the cut with built-in connecting bolts before removing the used electrode unit,

Fig. 5

the cut with the change carriage positioned in the installation position, on which a new unit of the electrodes is centered,

Fig. 6

the cut with hydraulic pistons engaged in the area of the vessel bottom,

Fig. 7

the cut with the base plate centered on the interchangeable adapter after installing the connecting bolts and

Fig. 8

the cut with the built-in new unit and the ready-to-go change car.

In a metallurgical vessel 1, which from an electric arc furnace on a Foundation 2 exists, a spent electrode unit 3 after its furnace journey and after cleaning with a cleaning hammer around the electrodes (anode) cleaned from the refractory masonry 4 and then the electrical Connections, coolant and thermocouple connections disconnected.

1 to 4 is the expansion of a used unit 3 and in FIGS. 5 to 8 the installation of a new unit 3 of electrodes shown.

Accordingly, a change carriage 5, or its carriage frame 5a, with one device moved under the vessel 1 at the hut hall level for the electrode exchange (Fig. 1).

At the ends of the changing device are hydraulic cylinders 6 with piston rods in pairs 6a arranged in the position provided with hydraulic connections of the four hydraulic cylinders 6 are connected. Store the hydraulic cylinders 6 in cantilever arms 7a of a change adapter 7 on the change carriage 5. On the Change car 5, the change adapter 7 is supported. The piston rods 6a extended and located at the tips of the piston rods 6a Couplings 8 are in mating couplings 1b attached to the vessel bottom 1a centered and locked (Fig. 2). After that, several are connected via the circumferentially distributed connections 9, for which the platform 7 by means of centering means 7b centered in corresponding receiving means 10a of a base plate 10 is (Fig. 3). The connections 9 can as a wedge, screw, u. Like. executed his. The base plate 10 is part of the unit 3 with the electrodes. After that Connecting bolts 11 between the bottom of the vessel 1a and the base plate 10 solved (Fig. 4). This can be followed by the one connected to the hydraulic cylinders 6 Interchangeable adapter 7 due to its own weight and the weight of the rest of the unit 3 can be lowered with the electrodes controlled by the piston rods 6a. At the Lowering the change adapter 7 is already centered on the change carriage 5. Then the coupling device 8 on the piston rod 6a from the Counter clutch 1b released and the hydraulic cylinders 6 retracted. Then will the change car 5 moved away with the used unit 3.

The installation of a new unit 3 will now be described with reference to FIGS. 5-8: 5, the change carriage 5 is positioned centrally under the Vessel 1 with a new unit 3 of the electrodes. The piston rods 6a extended and the coupling device 8 on the piston rod 6a is in each case connected to the associated mating coupling 1b on the vessel bottom 1a and locked (Fig. 6). The base plate 10 and the interchangeable adapter 7 are on the interchangeable adapter 7 located centering means 7b, which in the corresponding receiving means Intervene 10a, centered. When lifting the unit, the centering of the Setup here automatically caused by their own weight.

According to FIG. 7, the base plate 10 becomes the vessel 1 through the centering means 7b and by the coupling device 8 on the piston rods 6a in connection with the corresponding receiving means 10a automatically centered. Unit 3 is lifted into the vessel 1. The unit 3 is then with the bottom of the vessel 1a screwed by means of the connecting bolts 11. The weight of the unit is 3 on the connection over.

Now (Fig. 8) the four coupling devices 8 of the counter clutches 1b are separated and the four hydraulic pistons are raised. The change car 5 can be extended empty.

The base plate 10, on which the unit 3 of contact electrodes rests, can be further Centering means 12 which, when lowered by the interchangeable adapter 7 of the Change car 5 dips into the car frame 5a of the change car 5.

LIST OF REFERENCE NUMBERS

1

vessel

1a

vessel bottom

1b

counter-coupling

2

foundation

3

unit

4

Refractory brickwork

5

change car

5a

wagon frame

6

hydraulic cylinders

6a

piston rod

7

AC adapter

7a

extension arms

7b

centering

8th

coupling device

9

connection

10

Base plate of the electrodes

10a

corresponding receiving means

11

connecting bolts

12

centering

Claims (11)

1. A method for changing the electrodes of an electrically operated metallurgical vessel (1), particularly an arc furnace, by replacing a unit (3) that includes contact electrodes arranged on a base plate (10) and having electrical connections (9), cooling means and thermal element connections with a new unit (3),
   characterized in that
   after being detached from the floor (1a) of the vessel, the used unit (3) is lowered onto a changing bogie (5) and/or changing adapter (7) placed in position for the purpose, and transported away, that the new unit (3) that has arrived on the changing bogie (5) and/or changing adapter (7) is mounted and secured to the vessel floor (1a) from below, the changing bogie (5) and/or changing adapter (7) being attached in position hydraulically via hydraulic cylinders (6) that are arranged in pairs, and the piston rods (6a) being inserted and locked in self-centring manner in coupling devices (8) to the side of the vessel floor (1a).
2. The method according to claim 1,
   characterized in that
   the changing adapter (7) connected with the hydraulic cylinders (6) is raised under the base plate (10) of the unit (3) with the contact electrodes and a connection is established between the changing adapter (7) and the base plate (10).
3. The method according to claim 2,
   characterized in that
   when the unit (3) including the contact electrodes is flush on the changing adapter (7), retaining bolts (11) located between the unit (3) including the contact electrodes and the vessel floor (1a) are detached.
4. The method according to any of claims 1 to 3,
   characterized in that
   the changing adapter (7) connected to the hydraulic cylinders (6) is lowered over the hydraulic cylinders (6) due to the dead weight of the unit (3) including the contact electrodes.
5. The method according to any of claims 1 to 4,
   characterized in that
   the changing bogie (5) and/or changing adapter (7) is positioned under the vessel (1) and four hydraulic cylinders (6) are connected to the vessel floor (1a).
6. The method according to any of claims 1 to 5,
   characterized in that
   after lowering of the changing adapter (7) and detachment of the coupling device (8) on the vessel floor (1a) and seating of the hydraulic cylinders (6), the changing bogie (5) and/or changing adapter (7) are removed.
7. A device for changing the electrodes of an electrically operated metallurgical vessel (1), particularly an arc furnace,
   characterized in that
   a changing adapter (7) with hydraulic cylinders (6) disposed in pairs is positioned so that it may be raised and lowered on a changing bogie (5) that is movable in centred manner under the vessel floor (1a), and that a coupling device (8) is provided on each of the piston rods (6a) thereof, which coupling devices are connectable in self-centring manner to a mating coupling member (1b) in the vessel floor (1a).
8. The device according to claim 7,
   characterized in that
   the coupling device (8) and the associated mating coupling member (1b) are individually lockable and unlockable.
9. The device according to either of claims 7 or 8,
   characterized in that
   the changing adapter (7) is furnished with extension arms (7a) arranged in pairs, in each of which a hydraulic cylinder (6) is retained.
10. The device according to any of claims 5 to 9,
    characterized in that
    the base plate (10) on which the unit (3) including contact electrodes is supported includes additional centring means (12), which engage in the frame (5a) of the changing bogie (5) upon lowering by the changing adapter (7) of the changing bogie (5).
11. The device according to any of claims 7 to 10,
    characterized in that
    centring means (7b) for corresponding seating means (10a) in the base plate (10) of the unit (3) are provided on the changing adapter (7) of the changing bogie (5), which centring means form a detachable connection (9) in the closed position.

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