Water droplet impact on high-temperature peanut oil surface: The effects of droplet diameter and oil temperature

Abstract

A series of experiments on water droplet interaction with high-temperature peanut oil were conducted and the effects of droplet diameter and oil temperature were discussed in the current study. Three typical regimes, including secondary jet, bubble and vapor explosion were observed during the impact process. Especially, water vapor explosion can be induced by solid-liquid contact (Toil≥241 °C) and liquid-liquid contact (Toil≥301 °C). The evolution model of water vapor was proposed and divided into three stages. Furthermore, to characterize the hazards of the vapor explosion, the heat values absorbed by single water droplet and itsmaximum fragmentized daughter droplet were both quantified. It is found that compared with the oil temperature, the droplet size has a more significant effect on the absorption heat of the droplet. For the solid-liquid explosion, with the decrease of the impact droplet diameter, the size of the vapor bubble increases, and resultantly the ratio of the absorption heat of the maximum daughter droplet to that of a single droplet increases. Additionally, the larger the impact droplet size is, the more daughter droplets are formed, resulting in a more violent explosion with long time.