不同收缩段宽度条件下硼硅酸盐玻璃全电熔窑的模拟研究

Simulation of the All-electric Borosilicate Glass Melting Furnace with Different Contraction Section Widths

硼硅酸盐玻璃是一种理想的药品包装材料,深入了解其熔化过程对生产高质量的药品包材至关重要。采用有限元法对全电熔窑收缩段宽度对熔融玻璃液循环过程的影响做了系统研究。经过分析,熔融玻璃液共有三种循环方式:电极处螺旋循环、熔窑上下循环和收缩段底部循环。主熔区的循环流动即电极处螺旋循环和熔窑上下循环的速度较快,收缩段底部循环的速度较慢,前者速度约为后者的100倍。收缩段底部循环的玻璃液共有两种循环模式:收缩段壁面环流和收缩段底部直流。随着收缩段宽度逐渐减小,收缩段壁面环流逐渐减弱,而收缩段底部直流逐渐增强。当底部收缩段缩小400 mm时,收缩段壁面环流几乎消失,仅存在收缩段底部直流,该收缩段宽度不利于熔融玻璃液的熔化和澄清。

Borosilicate glass is an ideal drug packaging and understanding the melting process of borosilicate glass is very important to produce high-quality drug packaging.The finite element method(FEM)was adopted in this study to systematically consider the influence of the contraction section width of an all-electric furnace on the molten glass melting circulation process.There are three circulation modes of molten glass in the all-electric furnace:spiral circulation at the electrode,upper and lower circulation in the furnace and bottom circulation at the contraction section.The circulation in the main melting zone,which are spiral circulation at the electrode and upper and lower circulation in the furnace are about 100times faster than that at the bottom circulation at the contraction section.There are two circulation modes of molten glass at the bottom of the contraction section:wall circulation at the contraction section and bottom direct current at the contraction section.As the width of the contraction section decreases,the wall circulation of the contraction section decreases,while the bottom direct current of the contraction section increases.When the contraction section is reduced 400 mm,the wall circulation of the contraction section almost disappears,and there is only bottom direct current at the contraction section.The width of the contraction section reduced 400 mm is not conducive to the melting and fining.