DE2838564A1 - CONTINUOUS CASTING GRILL - Google Patents

Description

HUBERT BAUER

PATENT ADVOCATE

II. HAI KK PAT-ANW .. M) THRINrIKR RTRASSR 83 / ECKEWnJIEr ₁ MBTnAKSP ,. D-BIOO AAr

German Patent Office Zweibrückenstr. 12th

8000 Munich 2

TKI.HKiJN (OI241) ΠΟ12ΟΟ TKIiIiCiHAMMR: 1'ATIiNTIIAfKR AACHEN

POSTSOHFiCK COLOGNE 231333-508 (BLZ 37010050)

DEUTSCHE BANK AG. AACHEN 2 502 (BLZ 3ÜO70O20)

IHBB SIGN THEIR! NEWS MY CHARACTERS

B / KBO62)

AACHEN August 30, 1978

Patent application

Ann. : ARBED S.A., Avenue de la Liberte, Luxembourg

Designation: Continuous casting mold

909812/0812

The present invention relates to a permanent mold for the continuous casting of metals, in particular steel, with simultaneous rotation of the melt within the mold with the help of electromagnetic forces.

The continuous casting chills are known to consist of metal, preferably copper, and represent hollow profiles, the outer shapes of which are arbitrary, while the inner shape determines the profile of the cast strand.

Since the advantages of continuous casting with electromagnetic stirring within the mold compared to conventional ones Continuous casting processes were recognized (it is mainly about an increased homogeneity of the cast body as well a greatly reduced content of impurities), new continuous casting plants with inductors are becoming electromagnetic Stirring removed and existing systems retrofitted for electromagnetic rotation.

To do this, the mold is surrounded by the stator of an asynchronous machine, whose alternating magnetic fields generate currents in the mold wall and in the melt. Just the currents in of the melt are used to generate power, the currents in the mold, however, are undesirable, they weaken the desired fields and cause considerable losses in performance.

In order to be able to use the advantages mentioned, investments must be made for an expensive electrical installation. In addition, the installation of an electromagnetic inductor on the mold requires space, which is particularly important when converting existing ones Plants leads to problems.

The electrical power supply is therefore designed for a far higher output than without the shielding by the

- 4 - 909812/0812

- 4 conductive mold would be necessary.

There must be correspondingly stronger power transformers, thyristors, electronic control elements, as well as a stronger inductor can be used, which reduces the cost of electromagnetic rotation continuously cast steel unnecessarily.

In addition, the size of the inductor associated with the high output makes it easier to install it in an existing continuous caster often to spatial problems.

It is also known that magnetic fields are bundled with the aid of packets of thin metal sheets that are insulated from one another and can be conducted without major eddy current losses, and that by a subdivision into many thin ones Lamellas (see German patent specification 1,221,769) or wires with insulating intermediate layers cause induction unwanted currents in the mold can be avoided.

However, such a solution is out of the question for continuous steel casting, since the construction is complex it lacks mechanical strength, and the heat transfer coefficient is smaller than that of the usual mold are.

The invention is therefore based on the object of creating a permanent continuous casting mold in which the power consumption through the wall is as low as possible, so that the Structural size and the electrical power of the inductors used can be reduced to a minimum.

This object is achieved according to the invention by a mold,

909812/0812

which, in contrast to the well-known fine division into lamellas, has a rough division into axial or azimuthal Direction with one or a few slots that run exactly over the poles.

At most, the surface of the cuts is covered with an electrically insulating coating, preferably by flame spraying. Mistake; The introduction of intermediate layers is therefore dispensed with.

Furthermore, according to a further feature of the mold device according to the invention, it is essential that the inductors are designed for a low frequency of below 50 Hz, preferably 5-15 Hz. This will make the penetration of electromagnetic fields.

Corresponding to the coarse subdivision and the disappearing intermediate layers, there is therefore a good interlocking of the individual Elements possible and a good reliable mechanical strength can be achieved.

Thanks to the construction of the slotted continuous casting mold according to the present invention is prevented that within of the mold body itself large-scale, very power-consuming Currents are induced.

As mentioned, the slots in the mold body can optionally run in the axial or in the azimuthal direction.

In order to strengthen the cohesion of the individual segments of the continuous casting mold according to the invention with axial slotting, the latter is spanned by at least one clamp underlaid with an electrical insulation material.

909812/0812

Even with azimuthal slots, the individual parts can be clamped, e.g. by means of brackets or by clamping in the lifting table.

The advantages offered by the continuous casting mold according to the present invention can be summarized as follows:

By slitting the "mold", the formation is more induced Currents in the mold largely suppressed. Due to the small number of slots - e.g. a single azimuthal one Cutting with gradation does not reduce the strength.

Even one slot has the consequence that the entire electrical installation that is required when installing the electrical rotary device in the existing or in a continuous caster to be created with smaller dimensions in terms of the required performance and thereby also becomes spatially smaller. This results in both savings in electrical energy, which reduce the cost price of the steel produced in this way, as well as the size of the inductor.

As already mentioned, the smaller inductor offers the possibility of using all existing strings in existing systems to be built in.

909812/0812

Claims (4)

Patent claims: 1. Continuous casting mold made of metal, preferably made of copper, for continuous casting of metals, with an inductor for electromagnetic stirring of the melt in the mold, which is a hollow profile, the shape of which on the outside is arbitrary and the inside is adapted to the profile of the strand to be cast, characterized in that the mold is in axial or azimuthal direction has a rough division with one or a few slots, which over the Poles run, and that the inductor is operated at a low frequency of less than 50 Hz. 2. Continuous casting mold according to claim I _1, characterized in that the surfaces of the cut surfaces are coated with an electrical insulator. 3. Continuous casting mold according to claims 1-2, characterized in that it is one of several fitting into one another Parts represents composite hollow profile. 4. Continuous casting mold according to claims 1-3, characterized in that it is by at least one with an electrical Clamp or bracket underneath the insulator is clamped. 909812/0812