Selective chemical fining of small bubbles in glass

Patent metadata

Field	Value
Publication number	US-11697608-B2
Application number	US-201916590072-A
Country	US
Kind code	B2
Filing date	Oct 1, 2019
Priority date	Oct 1, 2019
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

A method of fining glass is disclosed that includes flowing a molten glass bath through a fining chamber. The molten glass bath has an undercurrent that flows beneath a skimmer that is partially submerged in the molten glass bath. One or more fining agents are introduced into the undercurrent of the molten glass bath directly beneath the skimmer from a carrier gas. In this way, the fining agent(s) may selectively target the gas bubbles drawn under the skimmer within the undercurrent of the molten glass for removal. The method may be employed to fine molten gas produced in a submerged combustion melter. A fining vessel for fining molten glass is also disclosed.

First claim

The invention claimed is:

1. A method of fining glass, the method comprising:
supplying input molten glass into a fining chamber of a fining vessel, the input molten glass combining with a molten glass bath contained within the fining chamber and introducing entrained gas bubbles into the molten glass bath, the input molten glass having a density and a concentration of gas bubbles;
flowing the molten glass bath through the fining chamber in a flow direction, the molten glass bath having an undercurrent that flows beneath a skimmer, which is partially submerged in the molten glass bath, and through a submerged passageway defined in part by the skimmer; and
introducing a carrier gas into the undercurrent of the molten glass bath directly beneath the skimmer, the carrier gas comprising suspended particles of one or more fining agents, wherein the suspended particles of one or more fining agents have particle sizes in a largest particle dimension ranging from 0.05 mm to 5 mm.

2. The method set forth in claim 1 , wherein the carrier gas includes a main gas that supports the suspended particles of one or more fining agents.

3. The method set forth in claim 2 , wherein the main gas is air or nitrogen.

4. The method set forth in claim 1 , wherein the one or more fining agents includes a sulfate that decomposes to release O 2 and SO 2 fining gases.

5. The method set forth in claim 1 , wherein the one or more fining agents includes sodium sulfate, Cr 2 O 3 , WO 3 , carbon, aluminum, a carbonate, silicon carbide, oxidized metal powder, or combinations thereof.

6. The method set forth in claim 1 , wherein the fining vessel includes a housing that defines the fining chamber, and wherein the carrier gas is introduced into the molten glass bath from a plurality of nozzles that are supported within a floor of the housing.

7. The method set forth in claim 6 , wherein the plurality of nozzles are spaced apart along a width of the fining chamber beneath the skimmer to provide a row of carrier gas effervescence that extends transverse to the flow direction of the molten glass bath and rises upwards from the floor of the housing.

8. The method set forth in claim 1 , wherein the input molten glass has a soda-lime-silica glass chemical composition.

9. The method set forth in claim 1 , further comprising:
discharging output molten glass from the fining vessel, the output molten glass having a density that is greater than the density of the input molten glass and further having a concentration of gas bubbles that is less than the concentration of gas bubbles of the input molten glass.

10. The method set forth in claim 1 , wherein the suspended particles of one or more fining agents have particle sizes in the largest particle dimension ranging from 0.1 mm to 1 mm.

11. The method set forth in claim 1 , wherein the suspended particles of one or more fining agents constitute from 1 vol % to 30 vol % of the carrier gas.

12. The method set forth in claim 1 , wherein at least 95% of the gas bubbles in the undercurrent of the molten glass bath that passes beneath the skimmer have a size of less than 0.7 millimeters.

13. The method set forth in claim 1 , wherein the carrier gas comprising suspended particles of one or more fining agents is selectively introduced directly beneath the skimmer through a plurality of nozzles spaced apart across a width of the fining chamber to provide a row of carrier gas effervescence that extends transverse to a flow direction of the molten glass bath.

14. A method of producing and fining glass, the method comprising:
discharging combustion products from one or more submerged burners directly into a glass melt contained within an interior reaction chamber of a submerged combustion melter, the combustion products discharged from the one or more submerged burners agitating the glass melt;
discharging foamy molten glass obtained from the glass melt out of the submerged combustion melter;
supplying the foamy molten glass into a fining chamber of a fining vessel as input molten glass, the input molten glass combining with a molten glass bath contained within the fining chamber and introducing entrained gas bubbles into the molten glass bath, the input molten glass having a density and comprising up to 60 vol % bubbles;
flowing the molten glass bath through the fining chamber in a flow direction, the molten glass bath having an undercurrent that flows beneath a skimmer, which is partially submerged in the molten glass bath, and through a submerged passageway defined in part by the skimmer;
introducing a carrier gas into the undercurrent of the molten glass bath directly beneath the skimmer, the carrier gas comprising suspended particles of one or more fining agents, wherein the suspended particles of one or more fining agents have particle sizes in a largest particle dimension ranging from 0.05 mm to 5 mm; and
discharging output molten glass from the fining vessel, the output molten glass having a density that is greater than the density of the input molten glass and further comprising less than 1 vol % bubbles.

15. The method set forth in claim 14 , wherein the carrier gas includes a main gas that supports the suspended particles of one or more fining agents.

16. The method set forth in claim 15 , wherein the main gas is air or nitrogen, and the one or more fining agents includes sulfate particles suspended in the main gas, the sulfate particles decomposing in the molten glass bath to release O 2 and SO 2 fining gases.

17. The method set forth in claim 14 , wherein the one or more fining agents includes sodium sulfate, Cr 2 O 3 , WO 3 , carbon, aluminum, a carbonate, silicon carbide, oxidized metal powder, or combinations thereof.

18. The method set forth in claim 14 , wherein the glass melt in the submerged combustion melter and the molten glass bath in the fining vessel have a soda-lime-silica glass chemical composition.

19. The method set forth in claim 18 , further comprising:
forming the output molten glass discharged from the fining vessel into at least one glass container having an axially closed base and a circumferential wall, the circumferential wall extending from the axially closed base to a mouth that defines an opening to a containment space defined by the axially closed base and the circumferential wall.

20. The method set forth in claim 14 , wherein the suspended particles of one or more fining agents have particle sizes in the largest particle dimension ranging from 0.1 mm to 1 mm.

21. The method set forth in claim 14 , wherein the suspended particles of one or more fining agents constitute from 1 vol % to 30 vol % of the carrier gas.

22. The method set forth in claim 14 , wherein at least 95% of the gas bubbles in the undercurrent of the molten glass bath that passes beneath the skimmer have a size of less than 0.7 millimeters.

23. The method set forth in claim 14 , wherein the carrier gas comprising suspended particles of one or more fining agents is selectively introduced directly beneath the skimmer through a plurality of nozzles spaced apart across a width of the fining chamber to provide a row of carrier gas effervescence that extends transverse to a flow direction of the molten glass bath.

24. A method of fining glass, the method comprising:
supplying input molten glass into a fining chamber of a fining vessel, the input molten glass combining with a molten glass bath contained within the fining chamber and introduc

Assignees

• Owens Brockway Glass Container

Inventors

• Wang Zhongming
• Weil Scott
• Smith Roger P

Classifications

• C03C3/078

  containing an oxide of a divalent metal, e.g. an oxide of zinc · CPC title

• C03C1/004

  Refining agents (refining C03B5/225) · CPC title

• C03B5/225 Primary

  Refining (C03B5/18 takes precedence {; Refining agents C03C1/004}) · CPC title

• C03B5/2356

  Submerged heating, e.g. by using heat pipes, hot gas or submerged combustion burners (bubblers C03B5/193) · CPC title

• C03B2211/22

  by direct combustion in the melt · CPC title