An atomizer nozzle can take on many forms. The first atomizer nozzle, also called an aspirator nozzle, was invented by Dr. Thomas DeVilbiss of Toledo, Ohio, in the late 19th century for producing a fine spray of a liquid based on the Venturi effect. His device was used for spraying medicine on the back of his patients' throats. Atomizer nozzles can create atomization from a variety of mechanical means, which includes but is not limited to electrostatics processes, ultrasonic nozzle and centrifugal forces.
Atomizer nozzle Wikipedia
When a fast gas stream is injected into the atmosphere and across the top of the vertical tube, it is forced to follow a curved path up, over and downward on the other side of the tube. This curved path creates a lower pressure on the inside of the curve at the top of the tube. This curve-caused lower pressure near the tube and the atmospheric pressure further up is the net force causing the curved, velocity-changed path (radial acceleration) shown by Bernoulli's principle.
The difference between the reduced pressure at the top of the tube and the higher atmospheric pressure inside the bottle pushes the liquid from the reservoir up the tube and into the moving stream of air where it is broken up into small droplets (not atoms as the name suggests) and carried away with the stream of air.
They may be automated or manually operated, the latter being typically by means of a manual pump (rubber ball or piston), this being a traditional type of atomizer used for perfume.
Atomizer nozzles are used for spraying perfumes, for applying paint, in fuel injection systems, and in spray drying installations.