A DESIGN PROCEDURE FOR EFFERVESCENT ATOMIZERS

A methodology for the design of effervescent atomizers is described. T he objective is to achieve sprays of minimum mean drop size for any st ipulated values of liquid flow rate, air supply pressure, and air/liqu id ratio. Application of die method leads to optimum values for all th e key atomizer dimensions including the number and size of the air inj ection holes, and the diameters of the mixing chamber and discharge or ifice. It also enables optimum dimensions to be determined for a conve rgent-divergent nozzle should such a device be fitted to the nozzle ex it to improve atomization performance. Examples are provided to demons trate the application of the recommended design procedure and to illus trate the relative importance of various flow and geometric parameters in regard to their effects on atomization quality.