Method and device for producing glass article from glass melt

Abstract

A method for producing a glass article from a glass melt is provided that includes continuously introducing the glass melt into a stirrer vessel, stirring the glass melt in the stirrer vessel by at least one blade stirrer, continuously discharging the glass melt from the stirrer vessel, and shaping the glass melt to obtain the glass article. The blade stirrer comprises at least one stirrer blade fixed and basically vertical to a stirrer shaft of the stirrer vessel. The method is characterized in that: the stirring is sufficient to draw the glass melt located at a surface of the stirrer vessel into the stirrer vessel so that a formation of a surface layer of the glass melt with a different composition from the composition of the glass melt introduced is prevented or at least minimized; and the stirring is sufficient so that the glass melt which is located at a surface in the stirrer vessel is not drawn into the stirrer vessel or is drawn in only insubstantially.

Description

technical field [0001] The invention relates to a method for producing glass articles from glass melts. [0002] Furthermore, the invention relates to a plant for producing glass articles from a glass melt. Background technique [0003] Such methods and devices are known in principle, for example from documents DE 10 2006 060 972 A1, DE 10 2007 035 203 A1. [0004] The stirring device used here and the blade stirrer arranged in the device are usually designed in such a way that the following conditions are met: [0005] - Higher uniformity index H = N · v · ρnLD 2 m · > 6000 , in [0006] N: Number of stirring devices connected one after the other [0007] v: Stirrer speed [0008] ρ: Density of the glass [0009] n: number of stirrer blades [0010] L: Inte...

AI Technical Summary

Problems solved by technology

[0027] 2. With very high demands on the homogeneity of the glass melt, known methods and devices can no longer dissolve and stir (homogenize) these more viscous glass melt components

[0028] 3. The uppermost rotating stirrer blade located below the glass surface causes eddy currents which cause an overflow movement of the glass melt on the inner wall of the stirring device; into the glass melt

These lead to undesired changes in the composition of the glass melt in the stirrer vessel, changes in viscosity and density, inhomogeneities which can no longer be eliminated or can only be eliminated with considerable effort in subsequent processing steps , and ultimately lead to defects in the glass product to be produced (such as excessively disruptive streaks and bubbles), which in turn can lead to considerable economic losses, especially if the optical properties of the glass product are important

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