It is very important to predict the concentration of hazardous vapor in the air when some flammable or toxic liquid is released on the ground. In order to achieve the aim, the evaporation rate of released liquid must be known, which is based on understanding the evaporation dynamic process. In this paper, wind tunnel evaporation experiments of benzene was made to study the dynamic characteristics of evaporation process for a mono-component liquid. The evaporation rate was obtained by measuring the mass loss rate of the evaporating liquid. The experiments results indicated that the evaporation rate of benzene increased as wind speed or pool depth increased. When the evaporation area was the same, the evaporation rate decreased as the characteristic size of the liquid pool increased. And when the evaporation surface was located above the ground, the evaporation rate was greater than that of evaporation surface located on the ground. The evaporation process of benzene was influenced by wind speed, characteristic size of the liquid pool and degree of atmospheric turbulence, i.e. , the evaporation of benzene was controlled by boundary layer evaporation. So, during the process of developing an evaporation model of the substance such as benzene, which has stronger volatility and lower saturation concentration in the air, the basic evaporation process itself can be ignored. Moreover, the influence of pool depth on evaporation indicated that heat transfer was very important in the evaporation process. Heat transfer and mass transfer should be considered at the same time when an evaporation mathematical model is developed.
Journal of Chemical Industry and Engineering(China)
wind tunnel experiment