Glass & Oxides
Some oxides and salts have thermal and electrical insulating properties at room temperature and become conducive at high temperatures. Due to ionic conduction, the electrical resistance of oxides (1-10 Ω.cm at 1,500°C) means they can be heated and melted by induction.
Because they have weak thermal conduction at low temperatures and their resistivity decreases as the temperature goes down, the self-crucible direct induction technique can be applied using an equal skin depth to radius of load ratio.
A self-crucible is when a melt is kept inside an insulating shell (gangue) made of the same solid material to be melted. The bath can reach temperatures of 2,500°C without any contact between the bath and the inductor (no product contamination).
There are various startup techniques:
- Radiant load
- Gas burner
- Inductive load
Self-crucible direct induction melting is an ideal solution for continuous or batch melting processes with overflow or bottom tapping (induction spout).
This high-performance technology is industry-ready, flexible and can effectively be used to melt a wide range of workpieces with excellent energy efficiency.
• Crystal melting
• Special or technical glass melting
• Refractory oxide melting, developing phosphates
• Waste vitrification (residue from fume purification of household waste incineration, asbestos, etc.).
- High melting temperatures above 2,500°C
- Maximum energy efficiency (1-1.5 kWh/kg of glass cast)
- Low maintenance, no wearing parts
- Easily adjustable
- Wide use range (50-1,000 kg/production hour) with inductive powers of 100-2,000 kW
- Good thermal consistency for bath (no hot points and includes a cold roof)
- Flexible enough for production changes (load changes)