The Effects of Water Flow Rate on the Air Entrainment Process from Vertical Plunging Water Jet with Downcomer

This study is intended to research the characteristics of bubbles produced by the phenomenon of air entrainment. This phenomenon is used in the Jameson cell, a flotation system used to separate valuable minerals from impurities. This process has proven successful in providing high separation efficiency. However, the characteristics of hydrodynamic bubbles and water entrainment have not been widely described. Research was set up in the form of a water loop consisting of a pump, flow meter, nozzle, downcomer, and water box. Data collection is done by using a digital camera and a high-speed digital video camera with a backlighting system. The resulting image is processed with software to obtain quantitative data. Results indicate that increasing the water flow rate also causes the ratio of air to water to increase (air entrainment).Air Entrainment is natural phenomenon air carried out as a result of a fluid jet stream. Mass transfer deepens penetration because a high jet speed produces bubbles and tends to force those bubbles towards the flow. Increasing the water flow rate will expand the surface roughness to produce more bubbles. Thus, it can be concluded that there are three phenomena that will affect whether or not the discharge will increase the air entrainment process: depth of bubble penetration, area of bubble dispersion, and air entrainment rate.