Sleeve-type glass melt agitator for the vello and draw-down processes and method of preventing schlieren formation in a glass melt with same

摘要

The sleeve-type glass melt agitator has a rotatable cylindrical sleeve provided with openings or small loops in its outer surface. The sleeve type agitator is arranged vertically in a glass melt feed channel in a glass melt feed system for making glass tubes or pipes according to the Vello or down-drawn process. During formation of glass tubes or pipes from the glass melt the sleeve-type agitator is rotated as the glass melt flows downward to prevent formation of schlieren in the glass melt, which causes glass material losses.