The refining channel working under reduced pressure and at medium temperatures was modelled experimentally and mathematically. Bubble growth rate was measured in the temperature interval 1200-1400 deg C and pressures 15 to 50kPa for the lead glass melt with and without refining agent. The bubble nucleation temperature was determined and the glass foam on the level was observed using high-temperature observation, video recording and image analysis. The temperature-pressure areas were defined in which the bubble nucleation and glass foaming did not interfere with efficient refining. The simplified mathematical model of bubble growth or dissolution under nonisothermal conditions was formulated and applied to the mathematical modelling of glass melt and bubble behaviour in the refining channel.
