Drying new furnaces or after replacing refractory materials
- New furnaces or those with replaced refractory linings must undergo a staged drying process.
- At the early stage, raise the temperature slowly and maintain it for a long time because the furnace is cold and contains moisture in its materials.
- When below 400 °C, keep the furnace door open to release water vapor.
- When the temperature reaches 700 °C, hold for a period to ensure uniform furnace temperature.
Recommended drying schedule for a new furnace:
- 20–100 °C → 8 h
- 100–200 °C → 16 h
- 200–400 °C → 8 h
- 400–700 °C → 10 h
- For belt-type furnaces, when the temperature reaches 400 °C, operate the belt for a while for oxidation treatment to improve its lifespan.
Prevent corrosion from low-melting-point impurities
- Impurities in the green compact (such as S, Pb, Zn) can corrode furnace linings and heating elements.
- To extend furnace life, regularly clean the furnace chamber, especially the preheating zone.
- Avoid adding elements like S in powder metallurgy formulations to prevent contamination.
Regular cleaning of the furnace
- When using CO or carbon-containing gases, carbon can deposit on furnace walls and heating elements from decomposition.
- This can pollute the furnace, corrode refractories, and damage electrical elements.
Maintain furnace cleanliness
- Regularly remove iron oxide scale, graphite debris, zinc oxide, and other impurities inside the furnace.
Check electrical connections
- Inspect heating elements and wiring for loose connections to prevent arcing.
Leak detection
- Since the furnace operates under low dew-point conditions, inspect bolted flange connections regularly for leaks.
Avoid introducing oil-contaminated trays
- Oil inside the furnace can sharply raise the dew point, affecting normal operation.
Do not leave the furnace door open at high temperatures
- This can let in air and damage heating elements.
Strictly avoid over-temperature operation