MODELING OF BUBBLE REMOVAL FROM GLASSMELTS AT FINING TEMPERATURES

A new model based on the quasi-stationary approximation is developed f or removal of gas bubbles from glassmelts due to buoyant rise of bubbl es. The growth and rising of multicomponent gas bubbles in glassmelts are examined from the view point of interfacial mass transfer. It is s hown that the models for rising bubbles in glassmelts available in the literature are based on the quasi-steady approximation which is not v ery reasonable. The growth of a gas bubble initially consisting of nit rogen only is studied in a glassmelt whose diffusing gases are oxygen, water, carbon dioxide, sulfide and nitrogen. The proposed model based on the unsteady-state mass transfer (the quasi-stationary approximati on) is compared with the model based on the steady-state mass transfer (the quasisteady approximation). The former, which provides more rati onal and better descriptions of bubble behavior in refining processes compared with the latter, predicts rather shorter refining times than the latter.