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Method and apparatus for forming soot for the manufacture of glass

Imported: 24 Feb '17 | Published: 06 Jan '04

Daniel W. Hawtof, John Stone, III

USPTO - Utility Patents

Abstract

The present invention is directed to a method and apparatus for forming soot used in making glass, and in particular, optical waveguides. A liquid precursor (

66) is first fed into orifice (

52) of a liquid orifice insert (

48) within an injector (

44) positioned within an atomizing burner assembly, and is thereafter discharged from the injector into a pressurization chamber (

56). An atomization gas (

70) is also fed into the pressurization chamber (

56) to mix with the liquid precursor liquid stream (

68) which breaks into droplets (

76). The liquid precursor and atomization gas arm forced under pressure out of an atomization orifice (

32) on the face of the burner (

30) assembly. Flame gas (

74), reaction gas (

84) and shield gas (

82) are ejected from burner orifices (

40, 38, 36 and

34) to produce the flame. The atomized liquid precursor thus discharged is fed into the flame (

72) produced at the face of the burner assembly where the atomized liquid precursor reacts with the flame to form soot (

78) on a rotating mandrel (

80).

Description

Additional features and advantages of the invention are set forth in the detailed description, which follows, and in part will be apparent from the description and claims when read in conjunction with the accompanying drawings. Other advantages of the invention will be realized and attained by the method and apparatus particularly pointed out in the written description and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention, and are not in any way meant to limit the invention which is defined by the appended claims. Moreover, the accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention, and together with the description serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a reactant delivery system in accordance with the present invention.

FIG. 2 is a top plan view of a preferred embodiment of the burner assembly of the present invention.

FIG. 3 is a side cross-sectional view of the burner assembly of the present invention taken along line

3

3 of FIG.

2.

FIG. 4 is a top plan view of a preferred embodiment of the liquid tube of the present invention.

FIG. 5 is a side cross-sectional view of the liquid tube of the present invention taken along line

5

5 of FIG.

4.

FIG. 6 is a top plan view of a preferred embodiment of the liquid orifice insert of the present invention.

FIG. 7 is a side cross sectional view of the liquid orifice insert of the present invention taken along line

7

7 of FIG.

6.

FIG. 8 is a schematic representation of liquid precursor droplets being discharged into a flame from the exit orifice of the preferred embodiment of the atomizing burner assembly of the present invention.

FIG. 9 is a partial cross-sectional view of a low turbulence embodiment of the burner assembly of the present invention illustrating the rounded orifice rim.

Claims

1. A method of forming soot for use in making glass said method comprising the steps of:

2. The method of claim 1 further comprising the step of fitting said injector with a removable liquid orifice insert defining a precision orifice having a diameter less than 0.011 inches.

3. The method of claim 1 wherein sate c) comprises introducing an inert gas into said chamber.

4. The method of claim 3 wherein step c) further comprises introducing nitrogen into said chamber.

5. The method of claim 1 wherein step c) further comprises introducing oxygen into said chamber.

6. The method of claim 1 wherein said gas consists essentially of oxygen and nitrogen.

7. The method of claim 1 wherein said liquid precursor comprises a metal.

8. The method of claim 1 wherein said liquid precursor comprises a siloxane.

9. The method of claim 8 wherein said siloxane is octamethylcyclotetrasiloxane.

10. The method of claim 7 wherein said metal comprises a metal selected form the Grotups IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table of Elements.

11. A burner assembly for delivering a liquid precursor into a flame as an aerosol to form soot for making optical waveguides, said burner assembly comprising:

12. The burner assembly of claim 1 wherein said injector comprises a liquid tube and a liquid orifice insert.

13. The burner assembly of claim 12 wherein said liquid orifice insert is releasably engaged with said liquid tube.

14. The burner assembly of claim 12 wherein said liquid tube included a plurality of atomization gas orifices circumferentially spaced around said liquid orifice insert.

15. The burner assembly of claim 2 wherein said liquid orifice insert comprises a material defining a precision orifice.

16. The burner assembly of claim 15 wherein said material comprises a jewel.

17. The burner assembly of claim 11 wherein the injector chamber is frustoconical and said atomization orifice is larger than said injector orifice.

18. The burner assembly of claim 11 wherein the portion of the burner face defining the atomization orifice is shaped to reduce turbulence.

19. A burner assembly for the liquid delivery of optical waveguide precursors, said burner assembly comprising:

20. The burner assembly of claim 19 wherein the orifice rim is rounded.

21. The burner assembly of claim 20 wherein the rounded orifice rim has a radius of between about ¼ and ⅔ of the atomization orifice diameter.