The water model of 1/4 scale of a 250 t RH vacuum refining unit at steel works has been established to study the effect of parameters including snorkel inside diameter (520 ~ 750 mm)

lifting gas flow rate ( 1 000 ~ 3 000 L/min)

immersion depth of snorkel (525 ~800 mm) and vacuum chamber pressure (0 ~25 kPa) on RH liquid circulation flow rate. Results show that with increasing lifting gas flow rate and immersion depth of snorkel

enlarging inside diameter of snorkel

and decreasing vacuum chamber pressure

the RH liquid circulation flow rate increases； in order to get larger flow rate

the immersion depth of snorkel should be ≥ 560 mm and the height of liquid surface in vacuum chamber should be ≥200 mm. The regression equation for circulation flow rate of liquid is obtained

and by adjusting corresponding process parameters for the 250 t RH unit at steel works

the production efficiency obviously increases.