Method of making glass sheets with gas pretreatment of refractory

Patent metadata

Field	Value
Publication number	US-10435323-B2
Application number	US-201515111658-A
Country	US
Kind code	B2
Filing date	Jan 12, 2015
Priority date	Jan 15, 2014
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A method of making a glass sheet includes exposing a refractory block material comprising at least one multivalent component to a reducing atmosphere for a time and at a temperature sufficient to substantially reduce the at least one multivalent component of the refractory block material. The method also includes flowing molten glass over the refractory block material that has been exposed to the reducing atmosphere while preventing substantial re-oxidation of the at least one multivalent component.

First claim

What is claimed is:

1. A method of making a glass sheet comprising:
exposing a refractory block material comprising iron oxide to a reducing atmosphere for a time and at a temperature sufficient to substantially reduce the iron oxide of the refractory block material; and
flowing molten glass over the refractory block material that has been exposed to the reducing atmosphere while preventing substantial re-oxidation of the iron oxide.

2. The method of claim 1 , wherein the refractory block material comprises at least one component material selected from the group consisting of zircon, alumina, titania, mullite, monazite, xenotime, spinel, zirconia, beta-alumina, and beta double prime-alumina.

3. The method of claim 1 , wherein the refractory block material comprises zircon.

4. The method of claim 1 , wherein the refractory block material comprises at least one grain boundary phase.

5. The method of claim 1 , where the reducing atmosphere comprises at least 95% nitrogen on a molar basis.

6. The method of claim 1 , wherein the reducing atmosphere comprises less than 2% oxygen on a molar basis.

7. The method of claim 1 , wherein the reducing atmosphere comprises at least 1% on a molar basis of at least one component selected from the group consisting of hydrogen and carbon monoxide.

8. The method of claim 1 , wherein the reducing atmosphere comprises at least 1% on a molar basis of at least one component selected from the group consisting of helium, neon, argon, krypton, and xenon.

9. The method of claim 1 , wherein the reducing atmosphere is present in combination with at least one getter material selected from the group consisting of carbon, magnesium, aluminium, barium, zirconium, and titanium.

10. The method of claim 1 , wherein the refractory block material is exposed to the reducing atmosphere for a period of at least 10 hours.

11. The method of claim 1 , wherein the refractory block material is exposed to the reducing atmosphere at a temperature of at least 500° C.

12. The method of claim 1 , wherein the refractory block material is exposed to the reducing atmosphere as the refractory block material is heated from ambient temperature to operating temperature and continues to be exposed to the reducing atmosphere during the step of flowing molten glass over the refractory block material for at least a time sufficient to coat the refractory block material with molten glass.

13. The method of claim 1 , wherein the method further comprises applying a coating material over the refractory block material after the refractory block material has been exposed to the reducing atmosphere for a time and at a temperature sufficient to substantially reduce the iron oxide of the refractory block material.

14. The method of claim 13 , wherein the coating material comprises glass.

15. The method of claim 13 , wherein the method further comprises raising the temperature above a temperature at which the coating is applied in order to encapsulate the refractory block material with the coating material.

16. The method of claim 1 , wherein the molten glass comprises an alkali oxide.

Assignees

• Corning Inc

Inventors

• Dejneka Matthew John
• Hanson Benjamin Zain
• Ketcham Thomas Dale
• Rustad James Robert
• Schiefelbein Susan Lee
• Vargheese Kochuparambil Deenamma

Classifications

• C03B17/064 Primary

  by the overflow downdraw fusion process; Isopipes therefor · CPC title

• C04B35/66

  Monolithic refractories or refractory mortars, including those whether or not containing clay {(making or repairing of linings F27D1/16)} · CPC title

• C04B2235/85

  Intergranular or grain boundary phases · CPC title

• C04B35/481

  containing silicon, e.g. zircon · CPC title

• C04B2235/6584

  at an oxygen percentage below that of air · CPC title