An improved mist generating apparatus is provided, the apparatus having a longitudinal axis (L), and first and second opposing nozzle surfaces (100,102) which define a nozzle between them. A first process fluid passage (28) has an inlet connectable to a supply of process fluid, and a process fluid outlet (110) on one or the first and second nozzle surfaces (100,102) such that the process fluid outlet (110) opens into the nozzle. The nozzle has a nozzle inlet (104) connectable to a supply of driving fluid, a nozzle outlet (108), and a throat portion (106) intermediate the nozzle inlet (104) and nozzle outlet (108). The nozzle throat (106) has a cross sectional area which is less than that of both the nozzle inlet (104) and the nozzle outlet (108). The nozzle extends radially away from the longitudinal axis (L) such that the nozzle defines a rotational angle about the longitudinal axis (L). A centre line (CL) of the nozzle extends from the nozzle throat (106) to the nozzle outlet (108) at an angle of between 50 and 80 degrees relative to the longitudinal axis (L).