Experimental Study of the Effect of Dense Spray on Drop Size Measurement by Light Scattering Technology

The effect of dense spray on drop size measurement by light scattering technology was studied using a Malvern instrument with five duplicated internal mixing airblast atomizers aligned with a laser beam. The correction factor data for multiple scattering were obtained. By regression analysis, an empirical equation was obtained that correlated the correction factor as a function of obscuration (OBS), Sauter mean diameter under dilute spray condition (SMD₀), and drop size distribution parameter for Rosin-Rammler distribution under dilute spray conditions (N₀). The experimental data showed definitely that the correction factor is not only a function of OBS and SMD₀, as proposed by Dodge, but also is a function of N₀. The correlation fits the experimental data very well, and can be used for practical purposes to correct the data from the Malvern drop sizer at high obscuration conditions.