The behaviour of a sparged vessel agitated by one, respectively two Rushton turbines positioned on the same shaft at various distances, was investigated. Hydrodynamic regimes and dissipated power were considered in air-water and air-starch solution systems. Two-phase flow maps were presented in terms of dimensionless criteria of similarity: flow rate number and Froude number for mixing. The transition to various hydrodynamic regimes is influenced upon both the apparent viscosity of the starch solution and rather the distance between turbines.