Experimental study and correlation development of droplet sizes created by nozzle injection of oil into a horizontal water flow

Abstract

The droplet of oil-in-water plays a crucial role in the performance of chemical process equipment. Accordingly, the present work is organized to develop a semi-empirical correlation to determine the Sauter mean diameter of oil droplets in the dilute oil-water flow field. In this regard, Experimental studies have been performed at three different average oil injection velocities (0.6, 0.9, and 1.2 cm/s) and three different average water velocities (0.438, 0.657, and 0.877 m/s) at turbulent conditions. The study is carried out in a horizontal pipeline with a diameter of 44 mm and 70D long. A 0.5 mm diameter needle is also utilized to inject oil at the center of the pipe's cross-section located 50D from the inlet. Image processing was applied to measure the diameter distribution of the oil droplet accurately. The linear, nonlinear regression techniques and Buckingham Pi theorem are used to derive a semi-empirical correlation for estimating the droplets' Sauter mean diameter in accordance with dimensionless parameters of the flow field. The results reveal that the PDF of the oil droplets' diameter presents a Gaussian distribution. The extension correlation is a function of oil and water Reynolds numbers that could predict the Sauter mean diameter with less than 6% errors in the turbulent flow field.