Tuckstone

Patent metadata

Field	Value
Publication number	US-11964900-B2
Application number	US-201816771313-A
Country	US
Kind code	B2
Filing date	Dec 19, 2018
Priority date	Dec 21, 2017
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

Fused tuckstone defining lower and upper surfaces. The lower surface includes a support surface to rest on metallic structure of a glass furnace, a tank surface intended to face an upper edge of a tank of the furnace, and a lower transition surface connecting the support and tank surfaces. The upper surface includes a superstructure surface to receive a side wall of a superstructure of the furnace and an upper transition surface connecting the superstructure and lower surfaces. At least a part of the lower transition surface has a crystal density of more than four times the crystal density at a depth of 4 centimeters below the lower transition surface, a crystal density being evaluated by the number of crystals having a surface area of more than 12 μm 2 per mm 2 of surface after polishing, the crystal density at the depth being evaluated after cutting of the tuckstone.

First claim

The invention claimed is:

1. Fused tuckstone having a lower surface and an upper surface,
the lower surface comprising:
a support surface intended to rest on a metallic structure of a glass furnace,
a tank surface intended to face an upper edge of a tank of said glass furnace, and
a lower transition surface connecting the support surface and the tank surface,

and the upper surface comprising:
a superstructure surface intended to receive a side wall of a superstructure of said glass furnace, and
an upper transition surface connecting the superstructure surface and the lower surface,

said fused tuckstone being characterized in that at least a part of the lower transition surface has a crystal density of more than four times the crystal density at a depth of 4 centimeters below said lower transition surface, such a surface being described as a surface with “skin microstructure”, a crystal density being evaluated by the number of crystals having a surface area of more than 12 μm 2 per mm 2 of surface after polishing, the crystal density at said depth being evaluated over the surface exposed after cutting of the fused tuckstone to said depth.

2. Fused tuckstone according to claim 1 , wherein at least a part of the upper transition surface is a surface having a crystal density of more than four times the crystal density at a depth of 4 centimeters below said upper transition surface.

3. Fused tuckstone according to claim 1 , wherein the entire lower surface is a surface having a crystal density of more than four times the crystal density at a depth of 4 centimeters below said entire lower surface.

4. Fused tuckstone according to claim 1 , wherein at least a part of the superstructure surface has a crystal density of less than four times the density at depth of 4 centimeters below said superstructure surface.

5. Fused tuckstone according to claim 1 , wherein a layer of an interfacing material, which is deformable and/or has a thermal conductivity of less than 1.0 Wm·m −1 ·K −1 , is arranged on at least a part of a surface with skin microstructure.

6. Fused tuckstone according to claim 1 , having a chemical composition in mass percentage based on oxides such that:
Al 2 O 3 +ZrO 2 +SiO 2 >80.0%.

7. Fused tuckstone according to claim 1 , comprising, in mass percentage based on oxides, more than 0.5% and less than 10.0% of a zirconia stabilizer.

8. Fused tuckstone according to claim 1 , having a chemical composition in mass percentage based on oxides such that, for a total of 100%:
Al 2 O 3 +ZrO 2 +SiO 2 is greater than 83.8% and less than 97.0%,
Y 2 O 3 is greater than 0.5% and less than 5.0%,
Na 2 O is greater than 0.1% and less than 0.6%,
B 2 O 3 : more is greater than 0.1% and less than 0.6%, and
the amount of oxide types other than Al 2 O 3 , ZrO 2 , SiO 2 , Y 2 O 3 , Na 2 O and B 2 O 3 is less than 10.0%.

9. Fused tuckstone according to claim 1 , having a chemical composition in mass percentage based on oxides such that:
ZrO 2 is greater than 12.0% and less than 45.0%,
SiO 2 is greater than 8.0% and less than 24.0%, and
Al 2 O 3 is greater than 35.0% and less than 60.0%.

10. Fused tuckstone according to claim 1 , having a chemical composition in mass percentage based on oxides such that:
ZrO 2 is greater than 80.0% and less than 97.0%,
SiO 2 is greater than 0.5% and less than 15.0%, and
Al 2 O 3 is greater than 0.2% and less than 3.0%.

11. Fused tuckstone according to claim 10 , wherein said at least one part of the lower transition surface has a crystal density of more than 650 crystals per mm 2 .

12. Fused tuckstone according to claim 10 , wherein the mean equivalent diameter of the crystals of said at least one part of the lower transition surface is less than 45 μm.

13. Fused tuckstone according to claim 1 , wherein the support surface defines a single foot or a set of feet, each foot having a terminal face intended to rest during use on the metallic structure, said terminal face not having a crystal densit of more than four times the crystal density at a depth of 4 centimeters below said terminal face.

14. Fused tuckstone according to claim 13 , wherein the area of the terminal face of the single foot or the cumulative sum of the areas (S 44 ) of the terminal faces of the feet represents more than 0.5% and less than 10% of the area of the support surface.

15. Fused tuckstone according to claim 13 , wherein a layer of an interfacing material which is deformable and/or had a thermal conductivity of less than 1.0 W·m −1 ·K −1 , is arranged on at least a part of the surface with skin microstructure, and wherein the interfacing material fills the volume which is delimited by the support surface and which extends up to the plane of said terminal face or faces.

16. Fused tuckstone according to claim 1 , wherein
the upper transition surface, at the junction between the superstructure and tank arms, comprises a curved upper junction surface with no ridges, which connects a horizontal surface of the superstructure arm and a horizontal surface of the tank arm, and/or
the lower transition surface, at the junction between the superstructure and tank arms, comprises a curved lower junction surface with no ridges, which connects a horizontal surface of the superstructure arm and a horizontal surface of the tank arm.

17. Glass furnace comprising:
a superstructure with an intermediate layer comprising a fused tuckstone according to claim 1 ;
a tank with an upper edge; and
a metallic structure,
wherein the support surface of the fused tuckstone rests on the metallic structure, the tank surface of the fused tuckstone extends facing the upper edge of the tank, and the superstructure rests on the superstructure surface of the fused tuckstone.

18. Method for production of a fused tuckstone according to claim 1 , the method comprising the following successive steps:
a) mixing of raw materials so as to form a starting batch;
b) fusion of said starting batch to obtain a bath of molten material;
c) casting of said molten material in a mold, and solidification of said molten material by cooling so as to obtain an intermediate piece which has a form of a tuckstone, the surface of said intermediate piece which is in contact with the mold having a crystal density of more than four times the crystal density at a depth of 4 centimeters below said surface;
d) removal of said intermediate piece from the mold; and
e) partial machining of the outer surface of the intermediate piece to obtain said fused tuckstone.

19. Method according to claim 18 , wherein in step e), the superstructure surface is machined and/or the support surface is not machined, and/or the tank surface is not machined.

20. Method for production of a furnace, said furnace comprising a glass melting tank, a superstructure extending above the glass melting tank, and a metallic structure supporting the superstructure, said method comprising integrating a fused tuckstone according to claim 1 as part of an intermediate layer of the superstructure between the metallic structure and a side wall of the superstructure,
wherein the support surface and superstructure surface of the fused tuckstone contact the metallic structure and the side wall of the superstructure respectively, and the tank surface of the fused tuckstone faces an upper edge of the glass melting tank.

Assignees

• Saint Gobain Ct Recherches

Inventors

• Cabodi Isabelle
• Vespa Pierrick

Classifications

• C03B5/43 Primary

  Use of materials for furnace walls, e.g. fire-bricks · CPC title

• C04B35/119

  with zirconium oxide · CPC title

• C04B35/4885

  with aluminium oxide · CPC title

• C04B2235/3201

  Alkali metal oxides or oxide-forming salts thereof · CPC title

• C04B2235/3217

  Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina · CPC title