Mathematical modelling of bubble removal from a glass melting channel with defined melt flow and the relation between the optimal flow conditions of bubble removal and sand dissolution

The bubble removal process was mathematically modelled in a continuous glass melting space with the intention of evaluating the impact of the glass flow character on the processes of bubble removal, when the bubble growth rate and the length of the channel were further variables. The different glass flow patterns in a model horizontal melting channel with a free glass level were implemented with linear temperature gradients applied on the glass level. The recently derived and introduced quantity called utilisation of the space and optimal conditions of beneficial glass flow patterns, which resulted in the spiral melt and bubble trajectories, were applied in all the examined cases by mathematical modelling. The optimal values of the utilisation of the space and the maximal bubble removal performances of the space were calculated. The values of the optimal space utilisation and maximal bubble removal performance were high over the entire considered range of the applied temperature gradients, bubble growth rates and channel lengths. The optimal conditions for bubble removal were comparable with those valid for sand dissolution which provided a chance to operate both processes effectively under identical melt flow conditions, i.e. in a common melting space. The application of the optimal flow character in glass melting furnaces appears promising for high performance facilities or for miniaturisation of the melting space and for decreasing the energy losses of the melting process.