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 bubbles), and bubble analysis. These experiments enable the direct determination of the gas permeability (the product of solubility and diffusivity) which describes the rate of gas exchange. In literature, little reliable data on the permeability can be found due to experimental problems with the most common method of studying gas exchange, gas extraction. For CO2 in television screenglass a permeability of about 2 . 10(-17) mol/(m s Pa) at 1305-degrees-C was found.