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http://dx.doi.org/10.4491/eer.2011.16.1.047

Investigations of Mixing Time Scales in a Baffled Circular Tank with a Surface Aerator  

Kumar, Bimlesh (Civil Engineering, Indian Institute Technology Guwahati)
Patel, Ajey (Civil Engineering, Indian Institute Technology Guwahati)
Rao, Achanta (Civil Engineering, Indian Institute Technology Guwahati)
Publication Information
Environmental Engineering Research / v.16, no.1, 2011 , pp. 47-51 More about this Journal
Abstract
The oxygen transfer rate is a parameter that characterizes the gas-liquid mass transfer in surface aerators. Gas-liquid transfer mechanisms in surface aeration tanks depend on two different extreme lengths of time; namely, macromixing and micromixing. Small scale mixing close to the molecular level is referred to as micromixing; whereas, macromixing refers to mixing on a large scale. Using experimental data and numerical simulations, macro- and micro-scale parameters describing the two extreme time scales were investigated. A scale up equation to simulate the oxygen transfer rate with micromixing times was developed in geometrically similar baffled surface aerators.
Keywords
Energy dissipation; Macromixing; Micromixing; Oxygen transfer rate; Surface aerators; Theoretical power per unit volume;
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