Method and apparatus for producing hollow fusing blocks

A method for producing hollow cast ingots by melting consumable electrodes in a slag bath in a short, water-cooled mould and using a water-cooled mandrel that is introduced into the mould from above, the method comprising:

• Simultaneously melting at least two consumable electrodes in the water-cooled mould, the electrodes having a diameter equivalent to at least 1.0 times the size of an annular gap between a part of the mould forming an outer casting cross section and the mandrel, the mould having a T-shaped flaring in an area of the consumable electrodes, wherein an inner diameter of the cast body is formed by the water-cooled mandrel that is introduced into the mould, the mandrel having a diameter that tapers downwardly in an area of a metal liquid level of a liquid heel;
• and adjusting the liquid level of the metal below a level of the flaring.

A system for producing a hollow cast body, comprising:

• a short, water-cooled mould;
• a water-cooled mandrel introducible into the mould from above;
• and at least two consumable electrodes having a diameter equivalent to at least 1.0 times a size of an annular gap between a part of the mould forming a casting cross section and the mandrel, the electrodes being arranged in the system simultaneously, the mould having a T-shaped flaring at least in an area of the consumable electrodes, the mandrel having a diameter that tapers evenly downwardly in an area of a solidification zone corresponding to a conicity of at least 1.5% relative to the diameter of the mandrel.