Droplet size distribution measurement of water in kerosene by the buoyancy weighing-bar method

The buoyancy weighing-bar method (BWM) is a method that requires a simple apparatus set up yet produce the high accuracy result in particle size distribution measurement both settling and floating particles. The principle of this experiment that measurement the density change in a suspension due to particle migration is measured by weighing buoyancy against a weighing bar hung in the suspension, and the particle size distribution is calculated using the length of the weighing bar and the time–course change in the apparent mass of the weighing bar. In this study, the BWM was applied to determine the separation time and droplet size distribution for liquid-liquid systems with the different density. The mixture of 99 % of kerosene and 1 % of water were used as samples. The data obtained of separation time of water-kerosene mixture by the BWM were analyzed by the gas chromatography, and the droplet size distributions were compared to Coulter counter method. Based on the data obtained, the BWM could be used to determine the optimal time of waterkerosene separation. The BWM also could measure the droplet size distribution of water in kerosene and the data obtained were comparable to that measured by Coulter counter method. Hence, the BWM is a novel method in separation time determination of water-kerosene mixture and droplet size distribution measurement of water in kerosene.