Study on behavior of liquid-solid contact on pool film-boiling (observations of collapse of vapor-film and contact angle)

摘要

The behavior of the liquid-solid contact in pool film-boiling, focusing on observations of a collapse of a vapor-film and a contact angle was investigated experimentally. Using a 2 mm diameter and 140 mm long platinum wire, pool film-boiling experiments were performed for saturated water at atmospheric pressure. In the experiments, a liquid jet from a nozzle was supplied on the superheated surface in the stable film-boiling, then the behavior of liquid-solid contact was observed. The experimental results showed that the propagative collapse of the vapor film occurred when the wall superheat was below 334 K for the top-jet case. The temperature was related to the thermodynamic limit of superheat, according to the heat conduction model. The measured dynamic contact angles, i.e., the angles between the liquid-vapor interfacial line and the heated wall, were close to the dynamic advancing contact-angles in room temperature.