Further data showing the effect of sand grain size on the refining of a glass

GT V01 1960 139-143

Some experiments already reported measuring the effect of sand grain size on the refining of a soda-lime-silica glass were repeated in a furnace that did not cause relatively rapid convection of the melt. The results in the two investigations for melts founded from one sand grain size differed, but showed that the exponential decrease in the number (n) of seed per cm3 of constant diameter (x) was not caused by the effect of convection on the motion of the bubbles. Therefore the rise of bubbles through the melt was not chiefly responsible for their removal. Four sand grain sizes were used, 0.22, 0.15, 0-114, and 0.077 mm. The seediness early in refining increased as the sand grain size decreased, but the rate of refining showed a maximum at 0.15 mm. Melts founded from 0.114 or 0.077 mm sand refined very slowly.

Michael Cable