DE1180899B - Method and device for achieving a uniform and smooth pouring stream of liquid metal - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school KI .: B 22 d

German class: 31 c -13

Number: 1 180 899AI & 4

File number: S59246VIa / 31c

Filing date: July 31, 1958

Opening day: November 5, 1964

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The invention relates to a method for preventing drops from being detached from a pouring stream liquid metal and to achieve the most uniform and smooth surface possible for the pouring stream, furthermore devices for carrying out the method.

It is known that the quality of metal products largely depends on how the metal pouring streams are used look. In any case, the aim is to have a beam that is as coherent as possible, little abto splashing drops and slight oxidation of the surface of the draining metal. One in terms of flow optimal design of the drainage opening and a reduction in surface tension are only possible to a very limited extent. In addition, these two basically well-known ways offer, especially with long pouring streams, only little success.

The described objects are achieved by the method according to the invention in that the ao Pouring stream is focused by a magnetic field or several overlapping magnetic fields. That Magnetic field should either be generated by an electric current flowing along the pouring stream or by a coil or coil arrangement surrounding the pouring stream, or by a combination from both. If the magnetic field is generated by a current in the pouring jet itself, the jet will indeed contracted inward and avoids tear-off of drops, but causes a small one Curvature of the pouring stream already creates instability in the sense of increasing curvature under the influence of the magnetic field. The method according to the invention therefore provides for the pouring stream additionally from a current-carrying coil to surround, whereby a magnetic field is generated, whose lines of force run in the pouring stream approximately in its flow direction. Such a field stabilizes the pouring stream in a manner analogous to how an electron beam is focused in a magnetic lens.

In general, for reasons of simplicity and economy, most of the magnetic field will be generated by a current flow in the pouring stream itself and an external magnetic field will only be used for additional stabilization. Since the contracting force of the current filaments is greater the closer they are to each other, a non-circular pouring stream will increase in circularity due to the magnetic field of its own current if the current flowing in it is direct current. However, if alternating current is used at such a frequency that the skin effect is noticeable
uniform and smooth pouring stream of liquid metal

Applicant:

Dipl.-Phys. Manfred Siebker,
Bremen, Rennstieg 25

Named as inventor:

Dipl.-Phys. Manfred Siebker, Bremen

occurs, this phenomenon can be compensated or even overcompensated so that the pouring stream looks practically round in its cross-section everywhere.

The use of electric current for heating of molds and also of pouring jets is known or proposed. It has also been suggested that the outflow rate influence of casting jets by the action of a magnetic field. These two effects can in the method according to the invention in a simple manner in addition to the effect of Basic idea of the invention can be achieved.

The method according to the invention not only holds the pouring stream together and stabilizes its cross-section, but also reliably guides it along its entire course. This makes it possible, in the further development of the invention, to enclose the area of the pouring jet with a practically gas-tight envelope into which an inert gas or a gas which has a ^{beneficial effect on the metallurgical or casting properties 1} can be introduced.

An advantageous embodiment of the coils or coil arrangement surrounding the pouring stream is that in the manner of a flexible hose. In this way, the desired course can easily be set will. It will be particularly advantageous when using an essentially gas-tight envelope, when the coil and sleeve form a structural unit.

Claims (6)

Patent claims: 1. Method of preventing drops from detaching from a pouring stream of liquid metal and to achieve the most uniform and smooth surface possible for the pouring stream, characterized in that the casting ray of the simultaneous action of a magnetic field running along it and one by an electrical potential difference between the beginning and the end of the pouring stream in exposed to this generated electric current. 2. The method according to claim 1, characterized in that the potential difference between The beginning and end of the pouring stream is an alternating voltage with such a frequency that the skin ίο effect noticeably appears. 3. The method according to any one of the preceding claims, characterized in that the Current through at least one of the coils surrounding the pouring stream and / or the coils in the pouring stream self-flowing electricity are controllable. 4. The method according to any one of the preceding claims, characterized in that the provided area of the pouring stream enclosed by a practically gas-tight envelope and iri the space between the pouring stream and the shell is an inert gas or the metallurgical or casting properties favorable influencing gas is passed. 5. Device for performing the method according to one of the preceding claims, characterized in that the coil (s) surrounding the pouring stream is (are) in the manner of a flexible one Hose is executed (are). 6. Device for performing the method according to claim 4, characterized in that that coil and sheath form a structural unit. Considered publications:
German Patent No. 307 225;
German Auslegeschrift No. 1 028 297;
Belgian patent specification No. 556 001;
U.S. Patent No. 1,978,222;
Goederitz: "Metallguß", 1955, p. 311. 409 710/324 10.64 © Bundesdruckerei Berlin