The Relaxation Phenomenon Research On Explosion Of Molten Aluminum In Water

Aluminum plays an important role in our daily life,but explosion accident induced by molten aluminum and water is one of the most severe hazards in aluminum industrical production.It threatens the life safety and results in great economics losses.Such accident origins from thermal explosion due to rapid vaporization of water in small space by contact of molten aluminum and water.And it is one of the vapor explosion.Facing to the above problem,we study the phenomenon of the explosion about molten aluminum and coolant water by experiment research and theoretical analysis.We build a mathematical model and discuss the explosive mechanism and transient heat transfer.In the experiment,we made the explosion about molten aluminum and coolant water by lifting the stopper which was in the bottom of the metal bucket rapidly.The result of the experiment: the explosion happens very fast and the time scale is in the millisecond level.The mass of aluminum and water,the temperature of water both affected the occurrence of the explosion.The relaxation on explosion of molten aluminum in water is the process from the beginning of fragmentation until the explosion occurred.The instability of aluminum droplet and rapid heat transfer will lead to further fragmentation,which makes the heat transfer efficiency increase and fragmentation region grow exponentially and eventually the explosion occurred.According to the result of model calculation,it can be concluded that with the increase of the number of droplet fragmentation,the time of single droplet breaked is decreasing and the speed is accelerating.The speed of heat transfer also increases.Meanwhile,the nucleation rate J increased sharply and exponentially when the steam temperature reached 570 K at a standard atmospheric pressure.Combining the nucleation rate and kinetic theory,it is possible to determine that the vapor explosion is likely to occur at this temperature.