화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.54, No.7-8, 1448-1455, 2011
Mechanism of mass transfer between a bubble initially composed of oxygen and molten glass
The bubble removal from molten glass is an important problem in glass melting process. In this paper, the mass transfer undergone by a bubble rising in molten glass is studied, the multicomponent feature being taken into account. In order to identify the time scaling of the bubble shrinkage, a careful dimension analysis is performed. A characteristic time to describe the mass transfer for each gaseous species in a bubble is introduced with an alternative expression of the permeability. This new permeability has the dimension of a diffusion coefficient, which is useful to compare to other transport phenomena. From the physical data known for soda-lime-silica glasses, a fast equilibrium state of water between a bubble and molten glass is determined. The opposite situation is observed for nitrogen. Experimental results giving the bubble size versus time with a dimensionless form leads to a good match at short time whatever the glass nature and the temperature. Finally, a simple equation to determine bubble size as a function of time is given, based on the dimension analysis previously established. (C) 2010 Elsevier Ltd. All rights reserved.