Apparatus for generating a mist comprising a conduit having a mixing chamber and an exit; a transport nozzle in fluid communication with the said conduit, the transport nozzle being adapted to introduce a transport fluid into the mixing chamber; a working nozzle positioned adjacent the transport nozzle intermediate the transport nozzle and the exit, the working nozzle being adapted to introduce a working fluid into the mixing chamber; the transport and working nozzles having an angular orientation and internal geometry such that in use interaction of the transport fluid and working fluid in the mixing chamber causes the working fluid to atomize and form a dispersed vapor/droplet flow regime, which is discharged as a mist from the exit, the mist comprising working fluid droplets having a substantially uniform size.