US3837832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making float glass
Assignee: PPG Industries Inc
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Filing: 1973-02-27
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Granted: 1974-09-24
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Expires: 1993-02-27
Abstract
Abstract In the production of high-quality flat glass by the float process, tridymite-frost stone defects are safely avoided by providing burners in the refiner zone of the furnace to shield the crown of that portion of the furnace from contact with alkali vapors, and at the same time providing not only a barrier that substantially separates the refiner-zone headspace from the melter headspace but also preferably a means associated with refiner-zone headspace for exhausting or venting it.
Inventors
- 👤 G Pecoraro
- 👤 Connell J Mc
- 👤 L Knavish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:55
CPC Classifications
C; C03; C03B; C03B5/00; C03B5/16; C03B5/167; B; B29; B29C; B29C2949/00; B29C2949/07; B29C2949/0715; B29C49/00; B29C49/02; B29C49/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
215 words
In the apparatus for making flat glass comprising a glass melting and refining furnace having a melting zone for receiving raw batch materials and for melting said raw batch materials to form molten glass and a refining zone for gradually cooling and conditioning said molten glass to prepare it for forming; a means for delivering conditioned molten glass from said refining zone to a forming chambEr; and a forming chamber comprising means for forming a continuous sheet of glass from delivered molten glass by floating it upon molten metal, cooling it and applying forces to it and means for withdrawing said continuous sheet of glass from said forming chamber, wherein said furnace has a silicacontaining crown facing said molten glass and separated therefrom by a headspace; the improvement comprising a. means for directing at least one stream of hot non-luminous gas into said headspace in said refining zone, said gas stream directing means having sufficient capacity to direct sufficient gas into said headspace in said refining zone to substantially prevent the flow of gases from said headspace in said melting zone into said headspace in said refining zone; and b. means for heating a gas to provide said stream of nonluminous gas at a temperature greater than that for molten glass in said refining zone.
Claim 2
Dependent Claim
215 words
In the apparatus for making flat glass comprising a glass melting and refining furnace having a melting zone for receiving raw batch materials and for melting said raw batch materials to form molten glass and a refining zone for gradually cooling and conditioning said molten glass to prepare it for forming; a means for delivering conditioned molten glass from said refining zone to a forming chambEr; and a forming chamber comprising means for forming a continuous sheet of glass from delivered molten glass by floating it upon molten metal, cooling it and applying forces to it and means for withdrawing said continuous sheet of glass from said forming chamber, wherein said furnace has a silicacontaining crown facing said molten glass and separated therefrom by a headspace; the improvement comprising a. means for directing at least one stream of hot non-luminous gas into said headspace in said refining zone, said gas stream directing means having sufficient capacity to direct sufficient gas into said headspace in said refining zone to substantially prevent the flow of gases from said headspace in said melting zone into said headspace in said refining zone; and b. means for heating a gas to provide said stream of nonluminous gas at a temperature greater than that for molten glass in said refining zone.
Claim 3
Dependent Claim
25 words
The apparatus according to claim 1 wherein said furnace has a wall member extending into said headspace between said melting zone and said refining zone.
Claim 4
Dependent Claim
32 words
The apparatus according to claim 1 further comprising an exhaust means connected to said furnace and communicating with said headspace in the immediate vicinity where said melting zone meets said refining zone.
Claim 5
Dependent Claim
32 words
The apparatus according to claim 3 wherein said furnace has a waist separating said melting zone and said refining zone and said exhaust means is connected to said furnace at said waist.
Claim 6
Dependent Claim
43 words
The apparatus according to claim 3 wherein said furnace has a wall member extending into said headspace between said melting zone and said refining zone, and said exhaust means is connected to said furnace in communication with said headspace in said refining zone.
Claim 7
Dependent Claim
69 words
The apparatus according to claim 1 wherein said furnace is provided with a pair of gas stream directing means and gas heating means, one combination on such side of said furnace; and wherein each said gas stream directing means and gas heating means comprises a burner for burning a fuel in the presence of an excess of oxygen and a nozzle extending into said headspace in said refining zone.
Claim 8
Dependent Claim
60 words
The apparatus according to claim 6 wherein said nozzles are extended into said headspace in said refining zone on opposite sides of said refining zone and said nozzles are positioned such that flow from each may be directed across said refining zone toward the other and such that flow from each may be directed upwardly with respect to the horizontal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |