Abstract
Production equipment, such as pumps and chokes, cause shear in oil-water mixture flow, forming smaller droplets in the system, which may lead to operational and separation problems. The objective of this paper is to provide new data on droplet sizes under different shear conditions in oil-water flow and compare it with model predictions.
New experimental data on droplet size distribution are acquired for a gear pump with an in-line camera, utilizing the bead sizing tool. The acquired data capture the effects of the dispersed phase volumetric fraction and shear intensity. Two prediction models for a centrifugal pump, namely, Pereyra (2011) model and Kouba (2014) model, are modified to enable droplet size distribution predictions for a gear pump. These models use the log-normal distribution and Rosin Rammler distribution methods, which have been found to match the acquired data very well.
The results demonstrate that droplets tend to decrease in diameter when the shear intensity increases. Moreover, the higher the dispersed phase volumetric fraction is, the larger the resulting droplets will be. The modified prediction model of maximum droplet size (dmax) is valid for dispersed phase volumetric fractions up to 15%. Comparisons between the acquired data and the proposed droplet size distribution prediction, which utilizes the modified dmax model, is very good with Normalized-Root-Mean-Square Deviation (NRMSD) between 4% and 6%. The proposed analysis can be extended to study other shear causing devices.
