А multi-vortex separator developed to increase the efficiency of air purification from aerosol particles in the paint shops of industrial enterprises. The results of numerical studies to determine the efficiency of separation of gas coming out of each hole located in the separator lid are presented. The influence of the height of the slots, the velocity of the gas flow and the size of the dispersed particles on the separation efficiency and hydraulic resistance of the device is considered. The dependence of the hydraulic resistance on the height of the slots and the average discharge velocity of the gas at the inlet to the separation element is obtained. Holes are installed in the separator, through which a larger number of elusive particles pass, which are recommended to be used for fixing the upper removable cover.