Engineering Simulation And Verification Of Molten-glass Stirring And Forming Behavior Of Float Glass

The composition homogeneity of the molten glass and the glass-forming process in tin bath are very important for the quality of float glass products.Accordingly,to produce high quality float glass,the molten glass must to be homogeneous and the parameter settings of the glass-forming process must to be reasonable.In float-glass production process the stirrers are installed in the waist to obtain homogeneous molten glass,the homogeneity of molten glass is improved by the forced stirring.In this study,the stirring process in the float glass furnace was simulated and analyzed by using the ANSYS Fluent 14.5 software;the vertical stirring and horizontal stirring were studied respectively.The physical modelings of these two types of stirring were carried out by using the principle of fluid similarity,and the regularity characteristics of the numerical simulation results were verified.Research shows that the heterogeneous body was stretched by the stirring and became thinner,the increased contact area increases the diffusion effect,so that improving the homogeneous of the molten glass.Methods of evaluating the stirring effect were presented.The parameters of the two types of stirrer were optimized.Under the condition of this furnace and vertical stirrer,the appropriate insertion depth of the stirrer was 0.170 m;the optimal stirring speed was 5.3 r/min.Under the condition of this type furnace and horizontal stirrer,the appropriate insertion depth of the stirrer was 0.145 m;the stirring speed should be in 4r/min~6r/min.The evolution process of molten glass in the tin bath was systematically studied by using numerical simulation method.The ANSYS Fluent 14.5 software and ANSYS Polyflow 14.5 software were used respectively to numerically simulate the flow process of molten glass in the tin bath entry end and the glass-forming process in the tin bath.The relative position of glass material point between the entrance and the vertical cross-section of the tin bath was created by observing the streamlines.In the simulation study of the molten glass flow process at the entry end of the tin bath,in combination with the information of the the middle part of the glass cross-section stria image,the state of the vertical section of the middle part of the cannal in the forming process was clarified.The edge section of the glass cross-section stria image was related not only to the state of the furnace but also to the spout lip,restrictor tile,and wetback tile.This research is important in understanding the molten glass flowing mechanism in the spout lip section.And,the influence of the spout lip installation on the glass evolution process was discussed.The best installation position of the spout lip was confirmed.This study can be used to guide the design and installation of the spout lip.According to the numerical simulation results and the molten glass flow law,a new spout lip structure was designed and presented in this paper.In additoin,this paper is important in improving the monitoring technology of the glass cross-section stria image in float glass production.In the glass-forming simulation part,the contour shape,velocity distribution,and thickness distribution of the glass ribbon in the tin bath in manufacturing glass of different thickness values were compared and analyzed.The simulated glass thickness values in this study were natural thickness,4,5,6,8 and 10 mm.This study extends the understanding of the characteristics of the glass-forming process in tin bath and is important for industrial production of high quality float glass and to optimiz the float glass forming process.