The Study Of Melt Flow In Glass Tanks With Bubbling Process And Its Application In E-glass Unit Melter

In this paper analytical and experimental results obtained have been divided into four aspects. Firstly, the strength of the buoyancy induced melt flow varies greatly with furnace scale and glass types. For furnaces of large scale production, the natural convection is strong enough to satisfy the need of the melting and refining. For furnaces of middle or small scale production, though the natural convection is obviously reduced, it still meets the requirement of the glass technology. For unit melter, the melt flow is too weak. The bubbling is hence a necessary measure to produce the forced convection for melting in the unit melter. Secondly, based on simulation of physical model, the bubble forming process at nozzle exit is discussed and its analytical expression is advanced, which indicate that bubble size depends on the balance of buoyancy, viscosity and inertia forces. A mathematical model for continuous bubbling system is established to predict the bubble size, which agrees well with the experimental data. Thirdly, the special attention has been paid to study bubbling induced flow pattern. Unlike the conventional flow pattern predicted by numerical simulation, the experimental show that its core section looks like that of an onion with two wings. This is because one usually employs the free tangential slide with rigid lid as the boundary condition for melt surface in computation. Based on the free surface condition the numerical results on the bubbling induced flow pattern are consistent with that observed in physical model system. At last, the flow pattern in unit melter has been described and discussed. The flow process in the melter is controlled by bubbling induced flow behavior while the temperature field shows minor effect. The distance between two rows of bubblers may be optimized according to the bubbling induced flow patterns.