Hydrodynamics of pulsating flow type apparatus (PFA), namely droplet disintegration, was investigated by use of theoretical approach and experimentally. Impact of several mechanisms on droplet sizes: Kelvin-Helmholtz instabilities, turbulence in the bulk of liquid and near walls of apparatus, dynamic and inertial mechanisms as well as high shear stresses are studied. It was found that oil droplet sizes in water in PFA (mean diameter of 20 mu m and the maximum diameter of 35 mu m) are 1.8 times smaller than in the stirred tank with Rushton turbine (maximum diameter about 70 mu m) at the same level of energy dissipation rate. By other words, according to the Kolmogorov theory the stirred tank with Rushton turbine needs 4.5 times more dissipated energy to get the same sizes of droplets (1800 W/kg for Rushton turbine and 400 W/kg for PFA). Comparison of PFA with tubular turbulent apparatus (baffled pipe) has shown similar advantages of PFA. It has been revealed that these effects attributed to the generally other mechanisms of droplet dispersion in PFA compared with usual apparatuses like stirred tanks, where the turbulence plays the main role in the droplet disintegration. Among these mechanisms are pulsations of velocity, acceleration and pressure, high shear stresses rate, and some instabilities. (C) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.