Hydrodynamics of a Centrifugal Turbine Agitator-Pump

Hydrodynamics and agitation energy of viscous fluids was considered in apparatuses with a centrifugal turbine agitator-pump applied in vacuum filtration systems for water softening. Using the Navier-Stokes equations we solved an axisymmetric problem in the variables: pressure-velocity, vorticity-flow function. A flow region behind turbine blades is represented as a pair of symmetrical macrovortices forming vortex tubes with vortex cores and potential flow between them. We determined hydrodynamic parameters such as: a circulation around a contour enclosing the vortices, the drag coefficient and pressure drop when moving blades, coordinates of centers of the macrovortices, radial, tangential, and axial flows and corresponding them mass flows of liquid. We determined a limiting mode of the absence of cavitation in the turbine and calculated energy dissipation and power criteria: parameters used to scale turbine agitators. The obtained data underlay the study of mass transfer in the vacuum filtration system designed to remove the calcium cations from water.