Method for refining molten glass-making materials

• US 3,926,607 A
• Filed: 02/10/1975
• Issued: 12/16/1975
• Est. Priority Date: 02/04/1974
• Status: Expired due to Term

• Current Assignee: Owens-Illinois Glass Container, Inc. (O-I Glass, Inc.)
• Original Assignee: Fred G. Pellett
• Inventors: Pellett, Fred G.
• Primary Examiner(s): Kellogg, Arthur D.
• Application Number:
  US05/548,414
• Time in Patent Office: 309 Days
• Field of Search: 65/134,135,136,180,331
• US Class Current: 65/134.7
• CPC Class Codes: C03B 5/187 with moving elements

Abstract

A method for removing gaseous inclusions from molten glass materials to provide a refined, molten glass. Cylindrical tubes, positioned concentrically about a common vertical axis of rotation, form an annulus for the passage of molten glass. One tube is then rotated about the common axis relative to the other tube, molten glass-making materials are introduced into the annulus formed by the tubes and pass downward between the walls of the tube; the motion of the rotating tube induces shearing action in the glass. The induced shearing action facilitates removal of gaseous inclusions which are formed when the glassmaking materials are rapidly melted. The rate of downward flow and therefore the residence time during which the molten glass is subjected to the shearing action, temperature of the molten glass-forming materials and amount of shearing action are controlled independently in the process. Experiments have shown that controlling these factors at predetermined levels can achieve maximum refining rates.

Claims

1. A METHOD OF REFINING MOLTEN GLASSMAKING MATERIALS COMPRISING THE STEPS OF:

FORMING A PASSAGE BETWEEN A CYLINDRICALLY SHAPED SURFACE AND A TUBULAR STIRRING DEVICE OF ABOUT THE SAME LENGTH AS THE CYLINDRICALLY SHAPED SURFACE;

INTRODUCING MOLTEN GLASS CONTAINING GASEOUS INCLUSIONS INTO THE PASSAGE AND DOWNWARDLY PASSING THE MOLTEN GLASS BETWEEN THE TUBULAR SURFACES;

ROTATING AT LEAST ONE OF THE CYLINDRICAL SURFACES AT A SPEED OF BETWEEN 30 AND 810 REVOLUTIONS PER MINUTE;

MAINTAINING THE GLASS TEMPERATURE BETWEEN 2550**F AND 2700*F;

CONTROLLING THE RESIDENCE TIME OF MOLTEN GLASS IN THE ANNULUS TO AN EQUIVALENT FLOW RATE BETWEEN 60 AND 150 GRAMS OF MOLTEN GLASS PER HOUR AND THEREBY CAUSING GASEOUS INCLUSIONS TO COALESCE AND TO FLOW UPWARDLY IN A DIRECTION OPPOSITE TO THE DOWNWARD FLOW OF MOLTEN GLASS-FORMING MATERIAL IN THE PASSAGE;

AND DISCHARGING MOLTEN GLASS HAVING A CONTROLLED NUMBER OF GASEOUS INCLUSIONS.

2. The method of claim 1 wherein the introduction into and the removal of molten glass from the annulus is substantially continuous.