Casting Method and Casting System for Aluminium or Aluminium Alloys

Abstract

In a casting method, or a casting system for aluminum, or aluminum alloys, aluminum melt is filled into a plurality of pans (15, 15′). Said pans (15, 15′) are used for treatment, if needed, and delivered to a casting station (20), in which they are subsequently emptied, and the melt is casted into semi-finished products. At least two filled pans (15, 15′) are provided in order to ensure a continuous casting operation in the casting station (20), the melt of at least one of which is drained into a mutual inflow channel (27).

Description

The invention relates to a casting method for aluminium or aluminium alloys according to the preamble to claim 1 and to a casting system for implementation of the method.

It is known from EP-A-1 607 156 to use, instead of so-called in-line casting with which the aluminium melt flows from a melting or a heat conservation furnace via a long channel to a casting station, and is subjected here to different treatments, ladles for the treatment and conveyance of aluminium melt to preferably a number of casting stations, and so to separate this process phase temporally from the actual casting operation. The ladles filled with melt are conveyed to at least one further stage and treated here, and are then delivered to the casting station where they are emptied.

The object which forms the basis of the present invention is to further improve and simplify the casting method of the previously specified type as well as a casting system for implementation of the method.

This object is achieved according to the invention by a casting method with the features of claim 1 and by a casting system with the features of claim 6.

Preferred further embodiments of the casting method according to the invention and of the casting system according to the invention form the subject matter of the dependent claims.

According to the invention, at the casting station at least two filled ladles can be provided, a respective one of which is emptied into a mutual inflow channel so that a continuous casting operation can be guaranteed. The consecutive emptying of the ladles provided can be implemented by opening their slide closures, preferably in a controlled manner. The ladles do not have to be conveyed to a further treatment station and from there to the casting station, but the treatment of the aluminium melt can advantageously be implemented in the ladle or ladles provided at the casting station and not yet subjected to emptying.

In the following the invention will be described in greater detail by means of the drawings. These show as follows:

FIG. 1—a side view of an exemplary embodiment of a casting system according to the invention for aluminium or aluminium alloys; and

FIG. 2—a top view of the casting system according to FIG. 1.

FIG. 1 diagrammatically shows a casting system for aluminium or aluminium alloys with which scrap aluminium is introduced as a base material into a melting furnace 10. However, blocks provided for remelting could also be used as the base material. The melt produced in the melting furnace 10 is introduced into a heat conservation chamber 12 of a filling station 11 from where it is respectively filled into a ladle 15 at regular intervals with the aid of an immersion pipe 13. The melting furnace 10 can preferably be an induction furnace which has, for example, a holding capacity of 1.75 t and in which 2 t material per hour can be melted. From the heat conservation chamber 12 with a holding capacity of 3.5 t ladles with a holding capacity of 2 t can then be filled, the other 1.5 t then remaining for further charging in the heat conservation chamber 12.

It is also possible to supply liquid aluminium to the filling station 11 as the base material or to fill it directly into the ladles 15.

The ladles 15 filled in the filling station 11 are preferably conveyed directly to a casting station 20, this being for example a continuous casting system, known in its own right, with a plurality of moulds 21, and in which the actual casting operation takes place. According to the invention at least two filled ladles 15, 15′ are respectively positioned at the inflow of the casting station 20 (according to the drawing two ladles are provided), of which a respective one is emptied into a mutual inflow channel 27 by opening its slide closure 25 (FIG. 1). The aluminium melt passes into the individual moulds 21 via the inflow channel 27.

Any possible treatment of the aluminium melt preferably takes place in the ladle or ladles 15, 15′ provided at the casting station 20 and which have not yet been subjected to emptying. Accordingly, during the casting operation the one ladle 15 containing the already treated aluminium melt is emptied, while the melt is treated in the other ladle 15′. This can involve the addition of alloy additions, or cleaning and homogenisation, and if necessary temperature regulation. Of course the treatment could already be implemented at least partially beforehand, i.e. before positioning the ladle at the inflow of the casting station 20 (for example the alloy additions can already be introduced before filling into the ladles 15, 15′ or an additional treatment station could be provided).

A fan wheel, for example, for injecting argon or nitrogen can be immersed into the ladle 15′ provided at the casting station and not yet subjected to emptying for the combined elimination of hydrogen, homogenisation and if necessary heat regulation, it also being possible to additionally mix small quantities of chlorine into the cleaning gas in order to eliminate any alkaline traces of contamination.

As soon as the one ladle 15 is emptied (or shortly before), the slide closure 25 of the other ladle 15′ is opened and the casting operation is continuously pursued, the emptied ladle 15 being replaced by a new one. Operation of the slide closures 25 is preferably controlled.

The conveyance of the ladles 15, 15′ from the filling station 11 to the casting station 20 takes place on rails or by means of incumbent cranes (FIG. 1 only shows a supporting frame 29 for the latterly specified version).

Claims

1. A casting method for aluminium or aluminium alloys wherein aluminium melt is filled into a plurality of ladles (15, 15′), if necessary is treated in the latter, and is delivered to a casting station (20) in which the ladles (15, 15′) are emptied, and the melt is cast into semi-finished products, characterised in that in order to ensure a continuous casting operation at least two filled ladles (15, 15′) can be provided at the casting station (20), the melt of one of which respectively is emptied into a mutual inflow channel (27).

2. The casting method according to claim 1, characterised in that the consecutive emptying of the ladles (15, 15′) provided takes place with controllable opening of their slide closures (25).

3. The casting method according to claim 1, characterised in that the treatment of the aluminium melt takes place in the ladle (15′) or ladles provided at the casting station (20) and not yet subjected to emptying.

4. The casting method according to claim 3, characterised in that alloy additions are added to the aluminium melt in the ladle (15′) or ladles provided at the casting station (20) and not yet subjected to emptying, or cleaning and homogenisation and if necessary temperature regulation is implemented.

5. The casting method according to claim 4, characterised in that a fan wheel for injecting argon or nitrogen can be immersed into the ladle (15′) or ladles provided at the casting station (20) and not yet subjected to emptying for the combined elimination of hydrogen, homogenisation and if necessary heat regulation, it also being possible to additionally mix small quantities of chlorine into the cleaning gas in order to eliminate any alkaline traces of contamination.

6. A casting system for implementation of the method according to claim 1, with a plurality of ladles (15, 15′) which can be filled with the aluminium melt at a first filling station (11) and which can be conveyed to a casting station (20) and can be emptied at the latter by opening their slide opening (25), means being provided for any treatment of the aluminium melt before casting, characterised in that at least two filled ladles (15, 15′) can be positioned at the casting station (20), one of which can respectively be emptied into a mutual inflow channel (27).

7. The casting system according to claim 6, characterised in that the means for any treatment of the aluminium melt are assigned to the ladles (15, 15′) that can be positioned at the casting station (20).

8. The casting system according to claim 6, characterised in that rails or cranes are provided for conveying the ladles (15, 15′) from the filling station (11) to the casting station (20).

9. The casting system according to claim 7, characterised in that rails or cranes are provided for conveying the ladles (15, 15′) from the filling station (11) to the casting station (20).

10. The casting method according to claim 2, characterised in that the treatment of the aluminium melt takes place in the ladle (15′) or ladles provided at the casting station (20) and not yet subjected to emptying.

11. The casting method according to claim 10, characterised in that alloy additions are added to the aluminium melt in the ladle (15′) or ladles provided at the casting station (20) and not yet subjected to emptying, or cleaning and homogenisation and if necessary temperature regulation is implemented.

12. The casting method according to claim 11, characterised in that a fan wheel for injecting argon or nitrogen can be immersed into the ladle (15′) or ladles provided at the casting station (20) and not yet subjected to emptying for the combined elimination of hydrogen, homogenisation and if necessary heat regulation, it also being possible to additionally mix small quantities of chlorine into the cleaning gas in order to eliminate any alkaline traces of contamination.