Oil–water separation using hydrocyclones enhanced by air bubbles

In order to improve the separation efficiency of dispersed oil from water by hydrocyclones, a new process of utilizing air bubbles has been developed to enhance the separation efficiency. The air bubbles attach themselves to the oil droplets and cause a decrease in the overall density of the phase, the difficulty of agglomerating can thus be circumvented. The air–liquid ratio of 1% was found to provide the best separation. When the inlet Reynolds number ranges from 14,000 to 16,000, the oil removal efficiency increases from 72% (air–liquid ratio 0%) to 85% (air–liquid ratio 1%). The process has been found to be very efficient in the separation of suspended oil from water.