Numerical Simulation And Model Experiment For Flow And Heat Transfer Of Melt In Glass Tank Furnace

In this paper, a detailed study on flow and heat transfer of melt in glass tank furnace has been presented by means of numerical simulation and model experiment, aimed at improving the quality of glass fusion.An analytical expression about the melting time of glass composition materials has been derived. The quantitative indexes, melting index (MI) and refining index (NI) have been proposed, with which the conditions of glass melting and refining processes can be evaluated respectively. Thus, the quantitative relations between the fusion quality and the fields of velocity and temperature for glass melt were found. The effects of the furnace structure, size and operation parameters upon the quality of glass melt were determined by using the refining index in the numerical simulation. The modeling results have been applied successfully into a color TV tube glass company. By adjusting the operation parameters of the glass furnace, the company has increased the glass quality rate by 20%, and benefited ï¿¥6.73 million within 2 months.The flow behavior of mixed convection has been studied in detail. It was found that parameters which characterize mixed convection are Gr/Re and Pe when inertial force can be neglected, and those are Gr/Re~2 and Pe when viscous force can be neglected. The flow of glass melt in tank furnace can be characterized by mixed convection that the inertial force could be neglected. Only when Gr/Re and Pe in the model are equal to those in the real glass furnace, respectively, can the similarity be realized. This method can replace the traditional approximate simulation method used for decades years that the condition of the equalization of Re and Gr between the model and the real furnace can be satisfied, while Pr has to be neglected. It was also found that there is significant error in quantitative analyses with the traditional approximate simulation.Based on the new similarity criteria, the model experimental installation has been established using the model liquid of glycerin mixed with syrup. The flow profile was visualized and measured with the technique of particle image velocimetry (PIV). The temperature control and measurement for model liquid were performed by using a 386 computer. It is the first time that the similarity problem of the model experiment for flow and heat transfer of melt in glass tank furnace has been solved successfully.Based on the above analyses, a new structure of glass tank furnace has been proposed, which could overcome the shortcomings of the traditional furnaces.