Air-liquid Mixing Systems & Liquid Feeding System in Pneumatic Spray Nozzles

Air-liquid Mixing Systems

There are three methods for mixing compressed air and a liquid for liquid atomization in the pneumatic spray nozzles.

〈Internal mixing type〉

Compressed air and a liquid are mixed inside a nozzle for generating atomization.
Generally, this type performs excellent liquid atomization.

■ 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.

  • Pre-mix type

    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.

〈External mixing type〉

Mixing compressed air and a liquid both outside the nozzle makes this type clog-resistant in general. This is also classified into an inner air type and an outer air type.

〈Impinging type〉

Air-stream entraining fine fog jets out from the nozzle and impinges against the other air-stream shattering the fog into even finer, more uniform droplets. This is an original method of IKEUCHI, "The Fog Engineers".

Liquid Feeding System

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.

〈Liquid pressure system〉


〈Liquid siphon system〉

Spray flow rate of a nozzle with the liquid siphon system differs depending on liquid siphon height (H).