Droplet Size Distribution of the Liquid Phase in a Vortex Separation Device

Abstract

The vortex form of multiphase flows is often organized in installations used in the electric power industry, the petroleum and chemical industries, and nuclear energy. Separators of various designs are used to separate gas-liquid flows. Predicting the composition of the dispersed phase is essential for the proper design, operation, and optimization of two-phase flow systems, because a parameter such as the efficiency of the separator strongly depends on the operating mode and the nature of droplet breakup. The dynamics of the gas–liquid flow under swirling conditions has been studied and is of great interest, and there are several mathematical models of droplet breakup. The analysis of the factors influencing the separation characteristics of the device depending on the characteristic zones of the droplet layer is carried out. On this basis, an experimental setup is uses to determine the size distribution of liquid droplets at the inlet to the vortex separation device with a change in the average velocity of the gas through the device from 15 to 23 m/s and a liquid phase rate of 150 kg/h. The electrical contact method is utilized in the study using a special two-needle probe with replaceable contact heads. In this work, experimental confirmation of the validity of using a logarithmic normal distribution is obtained to describe the dispersed composition of droplets at the swirler inlet. The calculation of the nonnormalized distribution function averaged over the section of the separation device for droplets flying through the interblade channels without interaction with the swirler blades is performed. Graphical dependences of the droplet distribution density function are presented. A calculated ratio is presented to determine the average value of the mass fraction of liquid droplets that does not interact with the swirler blades. An analysis of the dispersed composition of droplets flying through the interblade channels of the swirler without interaction with the blades shows that this phenomenon is typical only for fine droplets.