The Vaporizing Behavior of the Fuel Droplet of Water-in-oil Emulsion on the Hot Surface

The experiments were carried out to investigate qualitatively the effects of emulsion internal phase structure such as the size distribution of water droplets on the micro-explosion phenomena of water-in-'A' heavy oil emulsified droplets vaporizing on the hot surface. The results confirm that the size distribution of water droplets in the emulsified fuels plays a very important role in the boiling phenomena, in spite of the same water content included in the fuels. That is, Emulsified fuel 1 with fine- and uniform-size distribution of the internal water droplets has a longer life time than the neat fuel ('A' heavy oil) on account of a distinctive feature such as 'two stage vaporization'. In contrast, Emulsified fuel 2 with some coarse sizes of them has a life time less than a half of vaporization was caused by the destruction of the vapor film due to the 'violent micro explosion' of coarse-coalescent water droplets.