A study of the vapor explosion mechanism with single drops of high-temperature liquids and volatile liquids.

The vapor explosion produced by a single drop or plural drops of molten LiNO3 being dropped into tapped ethanol is studied by high-speed photography and pressure trace measurement. The temperature range of fragmentation to occur is firstly examined. The pressure trace with fragmentation is divided into two groups. Under the relatively large subcooling condition of a cold liquid, the typical vapor explosion whose pressure trace has at least three peaks and a period of reduced pressure occurs. The vapor bubble behavior is proved to be well-consistent with the pressure trace. The propagation phenomenon of vapor explosion is photographed under plural-drop experiments. The existence of a lengthy state of coherency is proved, and the pressure behavior is concluded as the control factor of the coherency. A qualitative and hypothetical modeling of the vapor explosion mechanism is made on the basis of the experimental results.