SOME PROBLEMS OF PRECISE MEASUREMENTS OF HEAT-TRANSFER COEFFICIENTS IN GLASS MELTS .1. MEASUREMENTS OF EFFECTIVE CONDUCTIVITY

In the paper the method of measurements of the so-called effective con ductivity of glass melts basing on characteristic of temperature gradi ent in a molten glass inside a refractory tank is analyzed. For this p urpose a computer model based on the solution of the radiative transfe r equation in a semitransparent medium was used. Among the papers on e ffective conductivity measurements published so far, only two containe d enough numerical information on the details of measurement which per mitted to perform the corresponding calculations. The authors of the p resent paper show what particular defects of experimental procedure co uld be the reason of surprising results reported in these publications , namely that the measured effective conductivity coefficient of a num ber of glasses was found to be lower than the radiative conductivity a lone.