1. Core Working Principle: Resistance Heating & Radiant Heat Transfer
Self-Generation of Heat: When an electric current passes through the silicon carbide (SiC) element, its inherent electrical resistance causes it to heat up directly, achieving very high temperatures (typically up to 1200°C - 1500°C or higher).
Primary Heat Transfer Method: At high temperatures, SiC elements primarily transfer heat to the furnace charge and lining via thermal radiation. This method is efficient and promotes uniform temperature distribution within the furnace.
2. Key System Components: Elements & Control
The Elements Themselves: Often manufactured as straight rods, U-shaped, or W-shaped elements to fit various furnace designs.
Supporting System: They must be used with a transformer or thyristor power regulator. This is because the electrical resistance of SiC changes significantly with temperature (from negative to positive temperature coefficient), requiring voltage adjustment to stabilize power and prevent damage from overcurrent.
3. Main Performance Characteristics
Advantages:
High-Temperature Resistance: Operating temperature is much higher than most metal heating elements.
Rapid Heating: High thermal efficiency allows for quick ramp-up to setpoint temperatures.
Corrosion Resistance: Good oxidation resistance and tolerance to various furnace atmospheres.
