溶鉄中への吹き込み窒素の吸収速度
1985 年 71 巻 1 号 p. 70-77
詳細
1985 年 71 巻 1 号 p. 70-77
A study was made on the rate of absorption of injected nitrogen in molten iron. Nitrogen was injected into the melt through an immersed alumina nozzle of 0.1 cm in I. D. and 0.3 cm in O. D. The immersion depth of the nozzle was 3.34.7 cm. The gas flow rate was 1.121.67 Ncm3/s. The oxygen and sulfur concentrations in the melt were varied widely. During the nitrogen absorption experiment, the bubble formation time was measured by using a pressure pulse technique.
The measured rate data are compared with calculations from a mixed control model of liquid-phase mass transfer and chemical reaction at the bubble-metal interface. Nitrogen absorption during bubble formation is taken into account in the model. From the comparison between calculation and experiment, the chemical reaction rate constant is obtained. It is shown that the chemical reaction rate constant decreases with increasing [%O]+[%S]/2. The rate constant for the bubble interface roughly agrees with that for the free surface of melt.
