Using a platinum wire of 1 mm in diameter and 160 mm in length, pool film-boiling experiments were performed for saturated and subcooled water at atmospheric pressure and the propagative collapse of the vapor film was examined. The temperature of a local-cooled spot which was suspected to have a large effect on the collapse of the water film was varied systematically in the experiments.
The experimental results showed that the propagation velocity of the vapor film collapse decreased and the surface temperature at the collapse increased with decreasing the cold-spot temperature. In particular, when the cold-spot temperature was below the thermodynamic limit of superheat of water, the surface temperature at the collapse increased remarkably. The propagation velocities of the collapse of the vapor film were similar to the rewetting velocities by a falling-film.