Bubble has an important role in separation processes such as desalination and flotation. The one way to produce bubble is air entrainment. Air entrainment phenomenon on vertical plunging jet has been studied with the aim to know the effect of nozzle and downcomer size on bubble penetration depth, gas entrainment rate, and bubble dispersion area. Experimental setup is in the form of water piping system consisting of pump, nozzle, downcomer, water flowmeter, air flowmeter and water pool. The visual data in the form of video and photograph taken by using digital camera and high speed camera with backlighting method. The visual data is then processed with the image processing program to obtain quantitative data. The results show that the nozzle diameter affects the air entrainment. Depth of bubble penetration, area of bubble dispersion, air entrainment rate, and liquid height entering into downcomer values are affected by the nozzle size.

Topics
Image processing, Desalination, Separation processes, Flow rate measurement, Bubble dynamics
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2019
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