The vaporizing behavior of the oil droplet of water-in-oil emulsions on the hot surface.

The difference of the vaporizing behavior has been observed by changing the size of water droplets in the emulsified fuel droplets of water-in`A'heavy oil on the hot surface. It was found that the size of water droplets in them plays an important role in the boiling phenomena, in spite of the same additive content of water. That is, the emulsified fuel 1 with fine water droplets has a longer life time than the case of`A'heavy oil for two stage vaporization; however, the emulsified fuel 2 with the coarse size of water droplets shortens the life time below a half of the case of`A'heavy oil in the film boiling region. A series of high speed photos revealed that the remarkable promotion effect of vaporization is caused by the destruction of the vapor film on the hot surface due to the micro explosion of coarse-coalescence water droplets.