Prediction of liquid circulation flow rate in RH degasser: improvement of decarburization at low atmospheric pressure

The two-fluid model coupled with population balance model was used for simulating the gas–liquid flow in the Ruhrstahl–Heraeus (RH) degasser. The predicted circulation flow rate was compared with that measured from a water model experiment to validate the mathematical model. Then, influence of snorkel immersion depth on liquid circulation flow rate was numerically investigated under an atmospheric pressure of 101 and 84 kPa, respectively. Predicted result indicates that the circulation flow rate of the RH degasser in the high-altitude area was severely reduced because of the decrease in atmospheric pressure. However, increasing the snorkel immersion depth from 0.5 to 0.7 m can compensate for the decrease in atmospheric pressure. Industrial test result indicates that decarburization rate is significantly enhanced by increasing the snorkel immersion depth. Through optimization, the percentage of heats with a final carbon content less than 0.002 wt.% is significantly increased from 22.0% to 96.4%.