A backlighted imaging technique for particle size measurements in two-phase flows

An imaging technique that uses backlighting has been developed to measure drop sizes in annular two-phase flows with small concentrations of drops in the gas phase. Advantages over conventional photography are realized in that data collection and analysis times are shortened considerably, and consistent unbiased results can be expected. A magnification of 1.9 was used to measure drops above 50 mu m. A drop size distribution was obtained for an air-water system as a superficial gas velocity of 30 m/s and a liquid flow of 20 g/s. The data are used to substantiate a theory for the rate of deposition.