I needed an atomising nozzle for another project, so I cooked up this little thing. It uses an annular air jet to create suction and to atomise the fluid passing through. The central (liquid) jet is 2mm diameter, and the annular (air) jet is 3mm OD, 2.6mm ID. At an air pressure of 50psi, it can pull a vacuum of about 21" water. The flowrate at zero head is about 3ml/s.
Here's a video showing the operation: