Transient Pressure and Vibration Events Resulting from High Speed Gas Injection Into Liquids

Trans-sonic gas injection was investigated using a combination of instrumented aqueous and iron bath physical models and high speed cinematography. It was found that, at gas injection velocities close to the speed of sound, severe gas column instabilities occur. The resulting violent disturbances, or “back-attack” events, in the liquid phase are thought to be a contributing factor to refractory wear near the point of injection. The characteristic vibration and pressure signatures of these instabilities can be detected and the instrumentation developed for this work could be adapted for application to full scale vessels.Contrary to the widely held view that back-attack is reduced by increasing injection rates, the results show that while the average frequency of back-attack events is reduced, the intensity of individual events increases with injection rate.