Air atomizing spray nozzles produces fine mist spray with the help of compressed air, liquid breaks into small droplets as air provides sharing effects on liquid droplets.
Various spray pattern are available, there are categorized into Flat and Round spray patterns. The droplet size can be adjusted by flow adjustment of compressed air.
Air atomizing nozzles are divided into two types Internal and External mix air atomizing nozzles. Those are available in various metals.
An air atomizing spray nozzles can work on three principles
as below :
1) Pressure Principle
2) SIPHON Principle
3) Gravity Head Principle
Choice of spray Nozzles
Each spray set-ups consists of an air cap and liquid cap which provide a specific spray pattern capacity and coverage performance
Inside Body Mixing
Liquid and air streams meet within nozzle and are mixed together and expelled through the same orifice. This internal mixing means the streams are not independent; a change in air flow will affect the liquid flow. This makes precise metering of the liquid more difficult than with an External Mix Set-up. Internal Mix set-up are able to produce the finest atomization of any of the XA set-ups, but they are generally not suitable for use with liquids which have a viscosity that is above 200 centipoise.
Out Side Body Mixing
The air and liquid streams exit the nozzle independently and are combined and mixed outside of the nozzles. Because there is no connection between the air and liquid lines within the nozzles, the air and liquid flow rates can be controlled independently, allowing precise metering of the liquid. The atomization can be controlled by adjusting the air flow rate more air produces finer atomization. In most cases these set-up do not atomize as finely as Internal Mix Set-ups.
External Mix Set-up used with liquid having a viscosity above 200 centipoise and for abrasive suspensions. Spraytech provides Engineering guidance for spraying high viscosity liquids.