Acceleration of Micro-Explosion of Emulsified Fuel.

点击翻译按钮获取中文摘要

The flashing temperature of superheated water droplets dispersed in fuels was measured to investigate the micro-explosion of emulsified fuels. For fuels, kerosene, diesel fuel and tetradecane were used. Water, aqueous methanol and ethanol solutions were used as the dispersed phase. The emulsions were stabilized by Span 80 whose concentration was 10 wt% of the dispersed phase. A small amount of the emulsion samples in a test tube were heated in an oil bath at a rate 2 K/min until explosive vaporization occurred. The emulsions were prepared by two methods: mechanically, using a homogenizer for 10 min atIt was observed that the flashing temperature had broad distribution. Thus, 30-50 samples were measured to determine the distribution of the flashing temperature for one emulsion. The flashing temperature of emulsions decreases with increasing fractions of the dispersed phase. Such a reduction is independent of the preparation method, mechanically or ultrasonically. The superheat, the difference of the 50% flashing temperature and the boliling temperature of the dispersed phase, was correlated as a function of the surface area per unit volume of emulsions. The coefficient of this function, however, were observed to depend on the substance of both the continuous and dispersed phase. This dependence was expressed as a function of the surface excess of surfactant which was determined by measuring the interfacial tension.