In a flat jet spray the liquid droplets are sprayed in the shape of a flat liquid layer, with different thickness according to the principle used to generate the spray. A flat jet spray nozzle serves the purpose of spraying onto a surface or an object moving in a transverse direction with respect to the one of the jet surface, a typical example being the nozzles in a car washing tunnel. The vast majority of flat spray nozzles used in the industry work according to one of the following principles.
- Inline flat jet
This is the general purpose flat jet nozzle, where the liquid enters the nozzle in line with the axis length and is fed to a pressure chamber, from where it is ejected through the nozzle orifice. Flow value and spray angle are determined respectively from the orifice cross section and the orifice edge profile.
- In-line straight jet
- These nozzles can be considered a special kind of flat jet nozzle, with naught degree spray angle. They are designed to produce a sharp stable stream, with powerful impact on a given point, and serve normally to perform cleaning processes or to cut soft materials.
- Spoon flat jet.
- In this type of nozzle the liquid is fed under pressure to a round outlet orifice, and then deflected onto a smooth profiled surface so as to assume a flat jet shape. This sophisticated design is of advantage since it offers a stronger jet impact using the same feed pressure. Higher efficiency comes from the very little energy required to just change the direction of the liquid flow, this being the only energy required to generate the flat jet.