Back to results
US 4,361,430 AGranted
Method of and apparatus for selectively heating molten glass stream marginal edges
AssigneePPG Industries, Inc.
InventorHarry S. Koontz
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneePPG Industries, Inc.
InventorHarry S. Koontz
Estimating the term…
Apparatus for selectively heating marginal edge portions of a stream of molten glass includes at least two independent heating elements presenting a substantially planar heating face toward the marginal edge of a stream of molten glass flowing in close proximity thereunder. A first set of the heating elements overlies a portion of the marginal edge adjacent a containing sidewall and the second set is positioned inboard of the first set relative to the central portion of the stream. Generated heat is directed primarily downward, e.g., greater than about fifty percent, and preferably greater than seventy-five percent toward first and second distinct areas of the marginal edge by a thermal insulating barrier positioned over the heating elements, to provide first and second localized zones of heating. The heating elements may be cantilevered through the sidewall in close proximity to the stream of molten glass.
In a method of passing a stream of molten glass through a chamber having side walls, a roof and a bottom, wherein heat losses along the side walls cause the glass stream to cool more rapidly in side portions than in center portions, the improvement comprising:
In a chamber through which a stream of molten glass flows from a melting section of a furnace to a forming chamber, having opposed side walls, a roof and a bottom, means for improving lateral thermal uniformity of the glass stream comprising:
Dependencies are inferred from the claim text.