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Bubble formation from a flexible hole submerged in an inviscid liquid

Loubière, Karine and Hebrard, Gilles Bubble formation from a flexible hole submerged in an inviscid liquid. (2003) Chemical Engineering Science, 5 (1). 135-148. ISSN 0009-2509

(Document in English)

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Official URL: http://dx.doi.org/10.1016/S0009-2509(02)00468-2


In the waste water treatment industry, a novel gas sparger based on flexible membranes has been used for the last ten years. The objective of the present work is to study the bubble formation generated from a flexible orifice (membrane). Firstly, the membranes are characterised with regard to their properties: wetting critical surface tension, expanding hole diameter, orifice coefficients, flexibility, critical and elastic pressures. The bubble formation phenomenon in an inviscid liquid at rest is studied experimentally for different membranes and gas flow rates. The variation in the bubble diameter, the bubble centre of gravity and the bubble spread on the membrane are determined as a function of time. An analytic model is proposed to describe the bubble growth and its detachment at a flexible orifice. This theoretical approach, developed by Teresaka & Tsuge (1990) for rigid orifices, is adapted to take into account the membrane features (elastic behaviour and wettability). The predicted bubble diameters at detachment agree with the experimental measurements; however, the model underestimates slightly the bubble formation times. The calculation of the various forces acting on the bubble in the vertical direction indicates that the real forces governing the bubble growth are the buoyancy force, the surface tension force, and near detachment the inertial force.

Item Type:Article
Additional Information:Thanks to Elsevier editor. The definitive version is available at http://www.sciencedirect.com The original PDF of the article can be found at Chemical Engineering Science website :http://www.sciencedirect.com/science/journal/00092509
Audience (journal):International peer-reviewed journal
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Institution:Université de Toulouse > Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE)
Laboratory name:
Deposited On:17 Nov 2009 16:36

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