Method and apparatus for delivering cased glass stream

Abstract

Apparatus for forming a cased glass stream having an inner core glass surrounded by an outer casing glass that includes a spout for delivering core glass from a first source through a first orifice. A second orifice is vertically spaced beneath and aligned with the first orifice, and is surrounded by an annular chamber that communicates with the second orifice through a gap between the first and second orifices. A tube delivers casing glass from the outlet opening of a casing glass spout to the annular chamber in such a way that glass flows by gravity through the orifices from the first and second sources to form the cased glass stream. A hollow tube within the casing glass spout is positioned with respect to the spout outlet opening for metering flow of casing glass through the outlet opening and delivery tube to the annular chamber surrounding the orifices. The interior of the hollow tube is coupled to a source of gas under pressure so as to maintain the tube interior, and the interior of the thin fall of casing glass through the spout outlet opening, at a pressure above ambient pressure surrounding the casing glass spout. This elevated gas pressure within the casing glass fall reverses the pressure differential between the interior and exterior of the spout outlet opening, so that any tendency for air to migrate through the refractory material surrounding the outlet opening and into the casing glass fall is eliminated.

Description

technical field [0001] The present invention relates to the streaming of glass for forming frits for the production of glassware, and in particular to a method and apparatus for streaming of so-called cased glass. In which the inner or core glass is surrounded by an outer or casing glass. Background technique [0002] Heretofore, it has been proposed to provide a cased glass flow for forming a glass vessel whose wall portions are delaminated. US Application Nos. 08 / 374,371 and 08 / 374,372 disclose techniques for delivering a stream of cased glass in which core glass from a first source is delivered through a first hole. The second hole is placed vertically below and aligned with the first hole, the second hole is surrounded by an annular chamber connected to the second hole by a slot between the first hole and the second hole . A heated tube conveys cased glass from a second glass source into an annular chamber surrounding the second aperture. The glass flows by gravity f...

AI Technical Summary

Problems solved by technology

Therefore, undesirably increased production costs

Moreover, producing cased glass with air bubbles or air bubbles in the cased layer causes an undesired increase in the reject rate, which further increases the production cost

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