Vacuum induction furnace
OTTO JUNKER offer a vacuum version of their medium-frequency coreless induction furnace.
Operating in the high and low vacuum range, this furnace is built in two versions.
A characteristic design feature of the first design type is that the vacuum is restricted to the melting crucible itself.
Induction coils with their supply lines for power and cooling water are placed outside the vacuum; they are freely accessible and clearly arranged in the open atmosphere. This design guarantees maximum reliability in furnace operation. It prevents glow discharges and eliminates the need for complex, vacuum-tight lead-through devices for electric power and cooling water lines. Moreover, this special design ensures that there can never be any hazardous contact between cooling water and liquid metal within a hermetically sealed area.
Typical applications for the JUNKER vacuum induction furnace are:
- carbon reduction in stainless steel melts
- deoxidation of stainless steel melts
- degassing of melts
- vacuum distillation of melts (i. e. removal of zinc)
A cooling air system between the furnace coil and the crucible lining protects the cylindrical, vacuum-tight furnace shell against overheating and, at the same time, allows easy checking of the condition of the refractory crucible lining by means of continuous temperature measurement on the cooling air ducts distributed across the circumference of the crucible.
The second design type consists of an induction furnace which is charged and tapped under vacuum.
Here the entire furnace is placed in a vacuum chamber. This chamber is linked to separate pouring and charging chambers which can be evacuated individually so that the complete melting and pouring process can be performed under vacuum. A furnace of this design can therefore meet the most complex metallurgical demands.
The special alloys and 'super' alloys thus obtained are used, e.g., in
- aerospace industry
- aircraft manufacturing