Ferrous Industry
Electric Arc Furnaces | Steel Ladles | Steel Degassers
Steel Degassers
The degasser operation imposes severe stress into the refractory lining system owing to rapid changes in temperature.
In the recirculatory degassing operation, liquid steel is forced from the ladle into an evacuated refractory chamber by atmospheric pressure. The low pressure in the chamber then allows the entrapped gases to expand and rise to the surface, resulting in the denser degassed steel returning to the ladle. The action of the degassing process also results in high turbulence within the steel volume giving rise to homogenization. Gases from the chamber are removed through off takes and coolers.
RH and DH Degassing Vessels
whereby steel is drawn into the chamber and after degassing leaves through the same leg. RH - Ruhrstaal - Heraeus using an upleg snorkel leg through which steel is drawn into the chamber and the denser degassed steel leaves through the down leg.
The DH degassing system is typically used in the production of high alloy and specialty steels from low tonnage electric arc furnace shops, whereas the RH degassing system is associated with high tonnage BOS shops producing low-carbon aluminum-killed steel.
RH degassing is generally preferred owing to the metallurgical advantage of downstream refining processes to produce large tonnage's of high quality lower cost continuously cast steel.
Development of the RH degassing system has led to:
RH-OB - oxygen blown to produce low carbon (less than 0.015%) steel.
RH-PB - powder injection of synthetic slag desulphurisers to remove or modify sulphur inclusions.
RH-OB - aluminum heating by the addition of aluminum metal.
Product Applications
