Research on the parameters of swirling jets from supply units and the efficiency of indoor air purification from urban dust

The results of studies of the parameters of swirling jets from supply units with air purification from dust of vertical surfaces of residential buildings are presented and their cleaning efficiency is estimated with determination of aerodynamic parameters using the proposed experimental installation. It is established that the efficiency of air purification of the supply unit from dust with a dispersion of 2.5–5 microns was 98.98%, with a dispersion of 8–10 microns – 99.34%. The paper presents empirical dependences of dust concentrations with particle sizes of 2.5–5 μm and 8–10 μm on the air velocity in the supply unit. According to the calculated data of the parameters of the supply jet in the service area, the air velocity corresponds to the permissible value for residential buildings, depending on the air flow rate. When comparing theoretical calculations and experimental data on air velocity on the axis of the inlet swirling jet at air flow rates of 90 and 140 m3/h, the difference was no more than 5.3–7.7%. With an increase in air flow rate from 90 to 300 m3/h, the coefficient of aerodynamic drag decreases by 1.3 times, and the pressure difference increases from 0.005 to 0.018 kPa. The results of the pressure difference and air aerodynamic resistance parameters are necessary for the justification and selection of a swirling supply fan.