Sodium fire suppression using liquid nitrogen

Abstract

Sodium has unusual fire hazards, notably a violent reaction with water. Experiments were conducted to examine the effectiveness of liquid nitrogen against sodium fire by heating stainless steel beakers (125 ml for 5 and 10 g sodium, and 250 ml for 20,40 and 80 g) At 285 °C, a vigorous surface reaction arises, resulting in a rapid temperature increase; ignition temperatures vary from 320-450 °C. At 600 °C, LN2 was added at a flow rate of 3 g/s. Applying LN2 to the sodium fire was effective as a sodium fire extinguisher. The linear correlation of the mass of sodium versus the mass of LN2 is approximately 1:2.9, whereas the analytical calculation of this ratio gives 1:3.0.