RECONSTRUCTION OF REAL SIZE DISTRIBUTIONS HIDDEN IN PHASE-DOPPLER ANEMOMETRY RESULTS OBTAINED FROM DROPLETS OF INHOMOGENEOUS LIQUIDS

Real process fluids such as emulsions and suspensions are optically ab sorbent as well as inhomogeneous. Using phase-Doppler anemometry (PDA) for investigating the spray cone, the inhomogeneities have led to inc omprehensible size distributions. In this paper, solutions of instant coffee and condensed milk, representing typical process fluids, were c hosen for PDA measurements in comparison with PDA applied to water dro plets with the same atomization process in order to clarify the reason s for the measured broad size distributions. By applying PDA to monodi sperse droplets and to ''monodisperse'' and real polydisperse sprays c onsisting of such fluids, it is shown how the measured size distributi ons arise. Based on this knowledge, the real size distributions are re constructed and compared with that of water atomization. Therefore, PD A can in future also be applied to real process fluids, and process co ntrol, based on the information provided by PDA, is coming nearer.