Evaporation of an Oil-in-Water Type Emulsion Droplet on a Hot Surface

Evaporation characteristics of an Oil-in-Water (O/W) emulsion droplet were examined experimentally. The evaporation time per unit of initial surface area of a droplet tau* was used to estimate the evaporation characteristics of droplets with different diameters and to compare a water droplet and an emulsion droplet. Results show that tau* of an O/W emulsion droplet is shorter than a water droplet in the Leidenfrost film boiling regime. The four evaporation modes of O/W type emulsion droplets were observed. These depended on the mixing ratio of water and oil, GS, and hot surface temperature, T-W. Increasing GS increases the emulsion droplet's Leidenfrost temperature when the droplet is used as a die-cast releasing agent. Microexplosions were observed during Leidenfrost film boiling when TW was greater than 250 degrees C. (C) 2005 Wiley Periodicals, Inc.