There are three methods for mixing compressed air and a liquid for liquid atomization in the pneumatic spray nozzles.
■ This internal mixing type is further classified into three types.
Inner air type
Compressed air flows in the center of the nozzle, while liquid flows along its circumference.
This type with a larger free passage is extremely good in clog resistance.
Outer air type
This is a general type of nozzle in which liquid flows in the center of the nozzle and compressed air along its circumference. Larger orifice size can be designed while spray droplets become a little coarser.
This type of nozzle accelerating spray velocity of the droplets provides a strong spray impact even at a low air-water ratio. Having a large turn-down ratio by utilizing compressed air, it is also suitable for cooling of objects in a high temperature range.
Two liquid feeding systems are available: a liquid pressure system supplying a pressurized liquid to a pneumatic nozzle and a liquid syphon system supplying a liquid sucked up by compressed air.