Float glass system incorporating an optical low-coherence interferometry assembly

Patent metadata

Field	Value
Publication number	US-10106450-B2
Application number	US-201615275969-A
Country	US
Kind code	B2
Filing date	Sep 26, 2016
Priority date	Jun 27, 2013
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A float glass system ( 10 ) includes a float bath ( 14 ) having a pool of molten metal ( 16 ). A chemical vapor deposition coater ( 32 ) is located in the float bath ( 14 ) above the pool of molten metal ( 16 ). The coater ( 32 ) includes at least one low-coherence interferometry probe ( 38 ) located in or on the coater ( 32 ) and connected to a low-coherence interferometry system ( 36 ). Another low-coherence interferometry probe 138 can be located outside an exit end of the float bath ( 14 ) and connected to the same or another low-coherence interferometry system ( 36 ).

First claim

The invention claimed is:

1. A method of determining a coater gap in a float glass system, comprising measuring a distance from a bottom of a chemical vapor deposition coater to a top of a glass ribbon in a float bath using at least one optical low-coherence interferometry probe, wherein said float glass system comprises a positioning system connected to the chemical vapor deposition coater, and a window located in a bottom of the chemical vapor deposition coater with the optical low-coherence interferometry probe located in the chemical vapor deposition coater and aligned with the window.

2. The method according to claim 1 , wherein the chemical vapor deposition coater includes a coater housing and wherein the optical low-coherence interferometry probe is located in the coater housing.

3. The method according to claim 1 , wherein the chemical vapor deposition coater includes a conduit in flow communication with a source of cooling fluid, and wherein the optical low-coherence interferometry probe is connected to an optical low-coherence interferometry system by an optical cable extending through the conduit.

4. The method according to claim 1 , wherein the optical low-coherence interferometry probe is located adjacent an exit end of the float glass system.

5. The method according to claim 1 , wherein the optical low-coherence interferometry probe is connected to a support and located adjacent an exit end of the float bath.

6. The method according to claim 5 , wherein the optical low-coherence interferometry probe is movably mounted on the support and the support is located outside the float bath.

7. The method according to claim 5 , further comprising measuring the distance from the bottom of the chemical vapor deposition coater to the top of the glass ribbon in the float bath using a plurality of other optical low-coherence interferometry probe.

8. The method according to claim 1 , wherein the optical low-coherence interferometry probe comprises a lens assembly located in a probe housing.

9. The method according to claim 8 , wherein the probe housing includes a transparent cover plate.

10. A method of determining a thickness of a glass ribbon in a float glass system comprising directing light from an optical low-coherence interferometry probe located in a chemical vapor deposition coater through a window positioned at a bottom of the chemical vapor deposition coater, wherein the optical low-coherence interferometry probe is aligned with the window, passing the light through the glass ribbon to a top of a molten metal, detecting a portion of the light that is reflected back to a detector from various interface surfaces.

11. The method according to claim 10 wherein a bottom surface of the window is aligned with a bottom of a coater.

12. The method according to claim 10 further comprising directing the light from a light source through a directional coupler into a sample arm, and directing the light that entered the sample arm to the optical low-coherence interferometry probe.

13. The method according to claim 12 wherein the light is further directed through the directional coupler into a reference arm.

14. The method according to claim 10 , wherein the chemical vapor deposition coater includes a coater housing and wherein the optical low-coherence interferometry probe is located in the coater housing.

15. The method according to claim 10 , wherein the chemical vapor deposition coater includes a conduit in flow communication with a source of cooling fluid, and wherein the optical low-coherence interferometry probe is connected to the an optical low-coherence interferometry system by an optical cable extending through the conduit.

16. The method according to claim 10 , wherein the optical low-coherence interferometry probe is located adjacent an exit end of the float glass system.

17. A method of determining a coater gap in a float glass system, comprising measuring a distance from a bottom of a chemical vapor deposition coater to a top of a glass ribbon in a float bath using at least one optical low-coherence interferometry probe connected to the chemical vapor deposition coater and also connected to an optical low-coherence interferometry system, wherein the chemical vapor deposition coater comprises a window located in a bottom of the chemical vapor deposition coater, and wherein the optical low-coherence interferometry probe is located in the chemical vapor deposition coater and aligned with the window.

18. The method of claim 17 , including adjusting the distance between the chemical vapor deposition coater and the glass ribbon.

19. The method according to claim 18 , wherein the chemical vapor deposition coater includes a coater housing and wherein the optical low-coherence interferometry probe is located in the coater housing.

20. The method according to claim 18 , wherein the optical low-coherence interferometry probe is located adjacent an exit end of the float glass system.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Jiao Yu
• Mccamy James W
• Hanekamp David

Classifications

• G01B9/02091

  Tomographic interferometers, e.g. based on optical coherence · CPC title

• C03B18/04 Primary

  Changing or regulating the dimensions of the molten glass ribbon · CPC title

• G01B11/14

  for measuring distance or clearance between spaced objects or spaced apertures (G01B11/26 takes precedence; rangefinders G01C3/00) · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• G01B11/06

  for measuring thickness {; e.g. of sheet material (thickness measurement by thermal means G01B21/085)} · CPC title