Droplet Dynamics in the Rotating Layer of a Separator with a Tangent Swirler

The intensification of heat and mass transfer is associated with the swirling of the flow using swirlers and the influence of separation layers near it; therefore, the strong dependence of the intensification process on the peculiarities of the movement of droplets in a rotating layer inside the device is obvious. The efficiency of the two-phase flow separation process is determined by the design of the separator used, as well as the fluid dynamics of the interacting flows; therefore, there is a need for a deeper understanding of the physical mechanisms developing in such complex flow fields. The design and principle of operation of a separation device with a tangent swirler are considered. To determine the main parameters of the layer, a computation of the movement of liquid droplets separated from the blades of the swirler is performed. The analysis of the forces acting on the droplet is carried out. The results of a calculation of the trajectories of droplets based on the inlet velocity of the gas and their diameter are presented. The total residence time of the droplet in the contact zone with the swirler blades is very significant and, by an order of magnitude, exceeds the separation time of a drop of sprayed liquid of equal diameter. The dependences determining the time of the droplet flight, the departure of the droplet into the separation zone, the height of the droplet separation, the number of interactions of the droplet with the blades, and the residence time of the droplet in the rotating layer are presented. Numerical calculations have shown that, when the dispersed phase moves in the rotating layer, the number of droplet impacts on the blades of a tangent swirler increases with decreasing droplet diameter and gas flow velocity. The results allow us to quantify the refresh rates of the surface of the interphase contact in the separation device with the tangent swirler.