GAS-EXCHANGE BETWEEN BUBBLES AND MOLTEN GLASS

Knowledge about the exchange of gases between bubbles and molten glass is of vital importance for bubble diagnosis. This process was studied using melting trials with very well-defined test bubbles (tracer bubb les), and bubble analysis. These experiments enable the direct determi nation of the gas permeability (the product of solubility and diffusiv ity) which describes the rate of gas exchange. In literature, little r eliable data on the permeability can be found due to experimental prob lems with the most common method of studying gas exchange, gas extract ion. For CO2 in television screenglass a permeability of about 2 . 10( -17) mol/(m s Pa) at 1305-degrees-C was found.