A STUDY ON THE MECHANISM OF SPONTANEOUS VAPOR EXPLOSIONS WITH SINGLE MOLTEN TIN DROPS AND WATER

The spontaneous vapor explosion generated by single drops of molten ti n submerged in water is investigated using high-speed photography and pressure trace measurement. The vapor film begins to collapse at the e dge of the disk-shaped drops and the collapsed zone spreads over the r est of the drop at a velocity of several meters per second. Explosion experiments in a two-dimensional channel with a narrow space are also carried out to observe more clearly the explosion configuration and th e fragmentation process. A model of the spontaneous vapor explosion wi th a single drop is presented on the basis of experimental observation s. In this model, the size of the vapor bubble compared with the cloud of high-temperature debris is assumed to have a strong relationship w ith heat transfer, and the collapse of the vapor bubble is also assume d to be induced by overexpansion and condensation.