Nozzles for spray injection - injecting into fluids or gases?

Whether the additive is being sprayed into a fluid or gas flow will affect the choice of nozzle.  In a fluid flow any nozzle that produces its spray pattern by impinging the additive liquid on surface after exit from the orifice will be unsuitable for injection purposes.  This means that both spiral and impingement nozzle designs will fail to produce a spray pattern if immersed in liquid.