METHOD FOR REFINING MOLTEN GLASS

• US 3,754,886 A
• Filed: 04/02/1971
• Issued: 08/28/1973
• Est. Priority Date: 04/02/1971
• Status: Expired due to Term

• Current Assignee: Owens-Illinois Glass Container, Inc. (O-I Glass, Inc.)
• Original Assignee: Raymond S. Richards, Robert R. Rough, St. John, Douglas F.
• Inventors: Richards, Raymond S., Rough, Robert R., St. John, Douglas F.
• Primary Examiner(s): Bashore, S. Leon
• Assistant Examiner(s): Schor, Kenneth M.
• Application Number:
  US05/130,672
• Time in Patent Office: 879 Days
• Field of Search: 65/134,178,180 55/203,159,400,36
• US Class Current: 65/134.7
• CPC Class Codes: C03B 5/2255 by centrifuging

Abstract

A method of removing undesirable gaseous inclusions, also known as seeds and bubbles, from seed containing or unrefined molten glass by continuously introducing this unrefined molten glass into a rapidly rotating contained glass mass, subjecting the unrefined molten glass mass to centrifugal forces substantially greater than gravity, and developing static pressure differences in the glass mass, resulting in pressure gradients in the molten glass and causing the gaseous inclusions to migrate to areas of lower static pressure and to the atmosphere from the molten glass, and subjecting the partially refined molten glass to increased centrifugal forces to remove additional gaseous inclusions, delivering refined molten glass from the contained glass mass, having reduced numbers of gaseous inclusions. The refining apparatus is a container for holding molten glass mounted for rotation about its axis of rotation. A refractorylined chamber within the container holds molten glass; the container has a centrally located top inlet, and a centrally located outlet at the bottom of the container. A slinger plate is positioned near the top inlet for diverting the entering molten glass stream within the container. A diverter plate is positioned within the container near the outlet of the container and causes the molten glass to flow adjacent the chamber wall on the way to the discharge, then subjecting the molten glass to an increased centrifugal force, and increasing the number of gaseous inclusions removed from the molten glass. The container has a flange, encircling the outside thereof. Pair of rotatable driving wheels support the flange and provide means for rotating the container.

Claims

2. The method set forth in claim 1 wherein the step of controlling the configuration of the chamber, the speed of rotation of the chamber, and the amount of glass in the chamber is such that the mass of glass in the chamber increases in radial width from the top of the mass of the glass to the apex of the paraboloidal void.

3. The method set forth in claim 1 wherein the step of controlling the configuration of the chamber, the speed of rotation of the chamber, and the amount of glass in thE chamber is such that the average axial velocity of the glass does not increase from the top of the mass of glass to the apex of the paraboloidal void.

4. The method set forth in claim 1, including the step of controlling the amount of molten glass in the chamber such that there is a substantial mass of glass between the apex of the paraboloidal void and the outlet of the chamber.

5. The method set forth in claim 4, including the step of redirecting the molten glass beneath the apex of the paraboloidal void, so that the molten glass in the area between the void and the outlet is caused to move radially outward toward the wall of the chamber in advance of the outlet.

6. The method set forth in claim 4, including the step of redirecting the molten glass beneath the apex of the paraboloidal void such that it is caused to move through a path adjacent the wall of the chamber before moving to the outlet.

7. The method set forth in claim 4, including the step of causing the molten glass between the apex of the paraboloidal void and the outlet to move radially outward from its apex of rotation and then generally radially inward to move portions of the molten glass through an area of centrifugal pressure greater than the pressure in the area at the axis of its rotation.

8. The method set forth in claim 1, including the step of controlling the speed of rotation of the chamber such that the height of the paraboloidal void formed in the molten glass is at least several times the maximum diameter of the paraboloidal void.

9. The method set forth in claim 1, wherein the step of controlling the amount of molten glass in the chamber is such that the radial thickness of the glass at the upper end of the chamber exceeds the radius of the paraboloidal void in the glass at the upper end of the chamber.

10. The method set forth in claim 1, wherein the step of introducing the molten glass into the chamber comprises directing the glass laterally such that molten glass merges with the mass of glass in the chamber adjacent the upper end of the chamber.

11. The method set forth in claim 1, wherein the step of controlling the amount of molten glass in the chamber is such that the height of the paraboloidal void is about equal to the depth of the glass beneath the apex of the paraboloidal void.

12. The method set forth in claim 1, including the step of controlling the configuration of the chamber such that it has a substantially constant diameter from the upper end to the lower end thereof.

13. The method set forth in claim 1, including the step of causing the molten glass between the apex of the paraboloidal void and the outlet to move radially outward from its axis of rotation and then generally radially inward to move portions of the molten glass through an area of centrifugal pressure greater than the pressure in the area at the axis of its rotation.

14. The method of refining molten glass which comprises:

defining a substantially cylindrical chamber having an axis of rotation and which has an upper end and a restricted lower end forming an outlet;

introducing molten glass wherein substantially all the glass constituents are molten and which contains entrapped gaseous inclusions into the open upper end of the chamber providing a mass of molten glass in the chamber;

rotating said chamber about its axis to subject portions of the mass of glass in the chamber to centrifugal force;

controlling the configuration of the chamber, the speed of rotation of the chamber, and the amount of glass in the chamber such that the mass of glass in the chamber forms a paraboloidal void having a top and an apex, and the glass mass has a radial thickness which increases progressively from the top to the apex of the void;

adding unrefined molten glass to the upper end of the chamber to maintain the mass of glass in the chamber substantially constant; and

substantially continuously removing refined molten glass from the lower end of the chamber to mainTain the mass of said glass substantially constant.

15. The method set forth in claim 14 wherein the step of controlling the configuration of the chamber, the speed of rotation of the chamber, and the amount of glass in the chamber is such that the average axial velocity of the glass does not increase from the top of the mass of glass to the apex of the paraboloidal void.

16. The method set forth in claim 14, including the step of controlling the amount of molten glass in the chamber such that there is a substantial mass of glass between the apex of the paraboloidal void and the outlet of the chamber.

17. The method set forth in claim 16, including the step of redirecting the molten glass beneath the apex of the paraboloidal void so that the molten glass in the area between the void and the outlet is caused to move radially outward toward the wall of the chamber in advance of the outlet.

18. The method set forth in claim 16, including the step of redirecting the molten glass beneath the apex of the paraboloidal void such that it is caused to move through a path adjacent the wall of the chamber before moving to the outlet.

19. The method set forth in claim 16, including the step of causing the molten glass between the apex of the paraboloid void and the outlet to move radially outward from its axis of rotation and then generally radially inward to move portions of the molten glass through an area of centrifugal pressure greater than the pressure in the area at the axis of its rotation.

20. The method set forth in claim 14, including the step of controlling the speed of rotation of the chamber such that the height of the paraboloidal void formed in the molten glass is at least several times the maximum diameter of the paraboloidal void.

21. The method set forth in claim 14, wherein the step of controlling the amount of molten glass in the chamber is such that the radial thickness of the glass at the upper end of the chamber exceeds the radius of the paraboloidal void in the glass at the upper end of the chamber.

22. The method set forth in claim 14, wherein the step of introducing molten glass comprises directing the glass into the open upper end of the chamber laterally such that molten glass merges with the mass of glass in the chamber adjacent the upper end of the chamber.

23. The method set forth in claim 14, wherein the step of controlling the amount of molten glass in the chamber is such that the height of the paraboloidal void is about equal to the depth of glass beneath the apex of the paraboloidal void.

24. The method set forth in claim 14, including the step of controlling the configuration of the chamber such that it has a substantially constant diameter from the upper end to the lower end thereof.

25. The method set forth in claim 14, including the step of causing the molten glass between the apex of the paraboloidal void and the outlet to move radially outward from its axis of rotation and then generally radially inward to move portions of the molten glass through an area of centrifugal pressure greater than the pressure in the area at the axis of its rotation.

26. The method of refining molten glass which comprises:

defining a chamber having an axis of rotation;

rotating said chamber about said axis;

introducing molten glass, wherein substantially all the glass constituents are molten and which contains entrapped gaseous inclusions into the chamber providing a mass of molten glass in the chamber;

continuing the rotating of said chamber about its axis to subject portions of the mass of glass in the chamber to centrifugal force, and thereby cause the mass of glass to form a portion of a paraboloidal void under the action of the centrifugal force; and

controlling the configuration of the chamber, the speed of rotation of the chamber, and the amount of glass in the chamber such that at least a portion of the mass of glass in the chamber forms a substantially cylindrical portion with a paraboloidal voId, said substantially cylindrical portion of glass extending from the top of the mass of glass in the chamber to the apex of the paraboloidal void, and having a radial thickness which increases progressively from the top to the apex of said void.

27. The method set forth in claim 26, wherein the step of controlling the amount of molten glass in the chamber is such that the radial thickness of the glass at the upper end of the chamber exceeds the radius of the paraboloidal void in the glass at the upper end of the chamber.

28. The method set forth in claim 26, including the step of controlling the configuration of the chamber, such that it has a substantially constant diameter from the upper end to the lower end thereof.

29. The method of refining molten glass which comprises:

defining a chamber having an axis of rotation and which has a restricted upper end and a restricted lower end forming an outlet;

introducing molten glass wherein substantially all the glass constituents are molten and which contains entrapped gaseous inclusions into the open upper end of the chamber providing a mass of molten glass in the chamber;

rotating said chamber about its axis to subject portions of the mass of glass in the chamber to centrifugal force;

controlling the configuration of the chamber, the speed of rotation of the chamber, and the amount of glass in the chamber such that a paraboloidal void is formed in the mass of glass;

adding unrefined molten glass to the upper end of the chamber to maintain the mass of glass in the chamber substantially constant; and

substantially continuously removing molten glass from the lower end of the chamber; and

causing the molten glass between the apex of the paraboloidal void and the outlet to move radially outward from its axis of rotation and then generally radially inward to move portions of the molten glass into the area of centrifugal pressure greater than the pressure in the area at the axis of its rotation.