Method for controlling foam production in reduced pressure fining

• US 20050155387A1
• Filed: 01/04/2005
• Published: 07/21/2005
• Est. Priority Date: 07/18/2001
• Status: Active Grant

• Current Assignee: Frank Woolley, James C. Hayes, Rand A. Murnane, Ronald W. Palmquist
• Original Assignee: Frank Woolley, James C. Hayes, Rand A. Murnane, Ronald W. Palmquist
• Inventors: Murnane, Rand A., Hayes, James C., Palmquist, Ronald W., Woolley, Frank
• Granted Patent: US 7,134,300 B2
• Time in Patent Office: Days
• US Class Current: 65/346
• CPC Class Codes: C03B 5/20 Bridges, shoes, throats, or other devices for withholding dirt, foam, or batch
• CPC Class Codes: C03B 5/202 Devices for blowing onto the melt surface, e.g. high momentum burners
• CPC Class Codes: C03B 5/205 Mechanical means for skimming or scraping the melt surface
• CPC Class Codes: C03B 5/2252 under reduced pressure, e.g. with vacuum refiners
• CPC Class Codes: C03B 5/262 Drains, i.e. means to dump glass melt or remove unwanted materials

Abstract

A method for controlling the foam produced when a molten material encounters reduced pressure in a vacuum chamber includes passing the molten material through an aging zone in the vacuum chamber in which the molten material is allowed to drain from between the bubbles of the foam and then collapsing the bubbles of the drained foam.

Claims

1. A method for controlling the foam produced when a molten material encounters reduced pressure in a vacuum chamber, comprising:

passing the molten material through an aging zone in the vacuum chamber, wherein the molten material is allowed to drain from between the bubbles of the foam; and

breaking the bubbles of the drained foam.

2. The method of claim 1, wherein breaking the bubbles of the drained foam includes using a mechanical rotator to stretch and rupture the bubbles.

3. The method of claim 1, wherein breaking the bubbles of the drained foam includes impinging a jet stream on the drained foam.

4. The method of claim 1, wherein breaking the bubbles of the drained foam includes spraying a stream containing particulate materials on the drained foam.

5. A method for controlling the foam produced when a molten material encounters reduced pressure in a vacuum chamber, comprising:

allowing the foam to flow from the vacuum chamber into a foam chamber separate from the vacuum chamber.

6. The method of claim 5, wherein the foam chamber is maintained at the same pressure as the vacuum chamber.

7. The method of claim 6, further comprising allowing the molten material between the bubbles of the foam to drain.

8. The method of claim 7, further comprising breaking the bubbles of the drained foam.

9. The method of claim 5, further comprising cooling and crushing the foam.

10. A method for controlling the foam produced when a molten material encounters reduced pressure in a vacuum chamber, comprising:

allowing the molten material to flow into the vacuum chamber through an inclined conduit, wherein bubbles in the molten material collect at a surface of the conduit.

11. The method of claim 10, further comprising removing the bubbles which collect at the surface of the conduit through a standpipe on the conduit.

12. A reduced pressure finer, comprising:

a finer chamber having a pressure below atmospheric pressure;

a first conduit for conducting molten material to the finer chamber, the first conduit being inclined to the vertical, wherein the bubbles in the molten material collect at a surface of the first conduit as the molten material flows through the first conduit; and

a second conduit for removing the molten material from the finer chamber.

13. The reduced pressure finer of claim 12, further comprising a standpipe hydraulically connected to the first conduit and through which the bubbles collected on the surface of the first conduit are removed.

14. The reduced pressure finer of claim 13, wherein the standpipe is positioned such that the level of molten material in the standpipe is above the level of molten material in the finer chamber.