1. Spray Pattern
Pneumatic flat fan atomizing nozzles are appropriate for humidifying and cooling of product, for web dampening, or for whenever a broad linear coverage is required (such as applying paint or food toppings). Pneumatic full cone atomizing nozzles are appropriate when circular impact or coverage is required (such as for fluid injection into a duct or pipe).
2. Liquid Supply Source
Whenever liquid can be supplied under pressure, it is most appropriate to use nozzles which function by the liquid pressure principle. Use of pneumatic atomizing nozzles operating by the siphon or gravity principle is more appropriate when liquid is to be sprayed in very low quantities (such as spraying disinfectants) and little pressure is required.
3. Internal vs. External Mix
In pneumatic nozzles, the supply of air or gas mixes with the liquid flow, breaking up the fluid into the smallest droplet particles, either inside (internal mix) or outside (external mix) the nozzle chamber. An internal mix nozzle is appropriate when water, low viscosity liquids, or liquids without solid matter are to be atomized. An external mix nozzle is more appropriate for atomizing viscous liquids which might otherwise tend to clog the nozzle. Low liquid pressures should be used with this type of nozzle due to its design.
4. Style of Nozzle
Series 136 nozzles (AirMists) are most appropriate when there is a need to finely atomize low viscous fluids, such as water. These are also able to have any of the various attachments on page 53 applied to them. This includes the pneumatic valve, which can separately and remotely control on-off operations, especially when intermittent spraying is required. Series 176 nozzles (ViscoMists) are external mix nozzles only and are most appropriate for spraying more viscous fluids (such as syrups and heavy oils) than AirMists are designed for. Series 166 AirMists include a solenoid for electronic activation of the nozzle through operation of a needle valve. This could be more appropriate if metered air is limited.