Investigating characteristics of a gas-droplet flow under different conditions of liquid dispersion by a pneumatic nozzle

An experimental setup has been created, and a laboratory sample of the pneumatic nozzle with a special design based on the use of the properties of cumulative jets, toroidal vortices and the Coanda effect has been tested. This nozzle may be used for dispersion of liquids and suspensions, in particular, coal-water slurry. The experimental setup allows obtaining a supersonic gas-droplet flow: with carrier phase velocity up to 500 m/s, at gas pressure up to 0.4 MPa, and liquid flow rate up to 500 kg/h. Shooting was used to determine a range of regime parameters, providing stable operation of the injector. Beyond this range, strong pulsations of the gas-droplet flow were observed. It has been established that in this range of modes the operating angle of a gas-droplet jet weakly depends on the liquid flow rate and gas pressure. The developed experimental and methodical base allows further measuring the dispersed composition of the generated gas-droplet flow with a view of optimizing the operation modes of the injector.