GEOMETRY AND PERFORMANCE OF A ROTARY CUP ATOMIZER

This article reports on the effect of geometry on controlled droplet atomization using rotary cups. Experiments were performed over a range of flow rates comparable to the one obtained with a commercial unit. A cup made of smooth surfaces was designed and tested in the present study. A model for predicting the droplet size as a function of cup geometry, fluid physical properties, and rotational speed was developed. One of the design parameters, the radius of the edge where fluid detaches from the cup has been identified as a key parameter in preserving droplet size uniformity under non–ideal conditions of operation. One specific design was compared to a commercially–available cup with grooves and teeth. Both atomizers achieved similar performance regarding droplet diameter (range 70 to 120
m) and droplet size uniformity. The range of flow rate where ligament formation was observed was from 40 to 300 mL/min.