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Method of forming an optical fiber preform by combustionless hydrolysis

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

Giacomo Stefano Roba, Marco Arimondi, Donata Piccolo, Sabrina Fogliani

USPTO - Utility Patents

Abstract

A method for manufacturing a glass preform includes supplying a first gaseous or vapor phase composition to a reaction chamber; supplying water as a second gaseous or vapor phase composition to the reaction chamber; reacting the water and the first gaseous or vapor phase composition to form an aerosol of glass particles; directing the aerosol along the reaction chamber, out of the reaction chamber, and toward a target; and depositing glass particles of the aerosol onto the target. The first gaseous or vapor phase composition is disposed to provide a hydrolyzable glass precursor. Walls of the reaction chamber have a temperature gradient in which a temperature of the walls increases in a direction of flow of the aerosol along the reaction chamber. Alternatively, a flow of the aerosol along the reaction chamber has a temperature gradient in which a temperature of the aerosol increases in the direction of flow.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the reaction process flow;

FIG. 2 is a drawing showing a cross-section of an apparatus according to the invention comprising an injection system and of a reaction chamber;

FIG. 3 is a drawing depicting a longitudinal section of the apparatus of FIG. 2;

FIG. 4 is a drawing depicting a longitudinal section taken along lines V—V in FIG. 5 of an embodiment of the injection system;

FIG. 5 is a drawing showing a cross-sectional view taken along lines IV—IV in FIG. 4 of the injection system of FIG. 4;

FIG. 6 is a schematic diagram depicting an embodiment of a stationary chamber in relation to a rotating target;

FIG. 7 is a schematic diagram depicting a translating chamber in relation to a rotating target;

FIG. 8 is a schematic drawing depicting the reaction chamber and the target with the respective heating elements;

FIG. 9 is a schematic drawing depicting a longitudinal section taken along lines X—X in FIG. 10 of an alternative embodiment of the injection system;

FIG. 10 is a schematic diagram showing a cross-sectional view taken along lines IX—IX in FIG. 9 of the injection system of FIG.

4 and of the reaction chamber;

FIG. 11 is a schematic diagram of a reaction chamber according to the invention;

FIGS. 11

a,

11

b and

11

c show the longitudinal and transversal temperatures profiles of the chamber of FIG. 11;

FIG. 12 is a schematic representation of a multiple nozzles injection system.

Claims

1. A method for manufacturing a glass perform, comprising:

2. The method of claim 1, wherein a temperature of the walls of the reaction chamber is greater than or equal to about 1,200° C.

3. The method of claim 1, wherein a temperature of the walls of the reaction chamber is less than or equal to about 1,600° C.

4. The method of claim 1, wherein a temperature of the walls of the reaction chamber is greater than or equal to about 1,200° C. and less than equal to about 1,600° .

5. The method of claim 1, wherein the aerosol comprises a first temperature at a time of formation of the aerosol, and

6. The method of claim 1, wherein the aerosol comprises a second temperature as the aerosol is directed out of the reaction chamber, and

7. The method of claim 1, wherein a temperature of the aerosol in the reaction chamber is greater than about 700° C. and less than about 1,200° C.

8. The method of claim 1, wherein the aerosol comprises a first temperature at a time of formation of the aerosol,

9. The method of claim 1, wherein the aerosol comprises a first temperature at a time of formation of the aerosol,

10. The method of claim 1, wherein the aerosol comprises a first temperature at a time of formation of the aerosol,

11. The method of claim 1, wherein a temperature of the first gaseous or vapor phase composition supplied to the reaction chamber is below a predetermined temperature, and

12. The method of claim 11, wherein the predetermined temperature is a temperature at which a hydrolysis reaction between the first and second gaseous or vapor phase composition is substantially incomplete.

13. The method of claim 11, wherein the predetermined temperature is less than about 800° C.

14. The method of claim 11, wherein the predetermined temperature is greater than or equal to about 600° C. and less than or equal to about 750° C.

15. The method of claim 11, wherein the predetermined temperature is about 700° C.

16. The method of claim 1, wherein a temperature of the target is greater than about 700° C.

17. The method of claim 1, wherein a temperature of the target is greater than about 800° C.

18. The method of claim 1, wherein a temperature of the target is less than a temperature of a stream of the aerosol impacting the target.

19. The method of claim 1, wherein a temperature of the target is at least 100° C. less than a temperature of a stream of the aerosol impacting the target.

20. The method of claim 1, wherein a temperature of a stream of the aerosol impacting the target is greater than or equal to about 800° C.

21. The method of claim 1, wherein a temperature of a stream of the aerosol impacting the target is greater than or equal to about 900° C.

22. The method of claim 1, wherein a temperature of a stream of the aerosol close to impacting the target is greater than or equal to about 1,000° C. and less than or equal to about 1,500° C.

23. The method of claim 1, wherein the reaction chamer comprises convergent walls, and

24. The method of claim 1, wherein the first and second gaseous or vapor phase compositions are reacted in a substantial absence of an unreactive carrier gas, an aerosol-free gas stream, or an unreactive carrier gas and an aerosol-free gas stream.

25. The method of claim 1, further comprising:

26. The method of claim 1, wherein, for a given distance along the reaction chamber:

27. The method of claim 1, wherein, for a given distance along the reaction chamber:

28. The method of claim 1, wherein the first gaseous or vapor phase composition is obtained by heating, under pressure, the first composition contained as pure liquid in a first supply tank,

29. A method for manufacturing a glass perform, comprising:

30. The method of claim 29, wherein a temperature of walls of the reaction chamber is greater than or equal to about 1,200° C.

31. The method of claim 29, wherein a temperature of walls of the reaction chamber is less than or equal to about 1,600° C.

32. The method of claim 29, wherein a temperature of walls of the reaction chamber is greater than or equal to about 1,200° C. and less than or equal to about 1,600° C.

33. The method of claim 29, wherein the aerosol comprises a first temperature at a time of formation of the aerosol, and

34. The method of claim 29, wherein the aerosol comprises a second temperature as the aerosol is directed out of the reaction chamber, and

35. The method of claim 29, wherein a temperature of the aerosol in the reaction chamber is greater than about 1,200° C.

36. The method of claim 29, wherein the aerosol comprises a first temperature at a time of formation of the aerosol,

37. The method of claim 29, wherein the aerosol comprises a first temperature at a time of formation of the aerosol,

38. The method of claim 29, wherein the aerosol comprises a first temperature at a time of formation of the aerosol,

39. The method of claim 29, wherein a temperature of the first gaseous or vapor phase composition supplied to the reaction chamber is below a predetermined temperature, and

40. The method of claim 29, wherein the predetermined temperature is a temperature at which a hydrolysis reaction between the first and second gaseous or vapor phase compositions is substantially incomplete.

41. The method of claim 39, wherein the predetermined temperature is less than about 800° C.

42. The method of claim 39, wherein the predetermined temperature is greater than or equal to about 600° C. and less than or equal to about 750° C.

43. The method of claim 39, wherein the predetermined temperature is about 700° C.

44. The method of claim 29, wherein a temperature of the target is greater than about 700° C.

45. The method of claim 29, wherein a temperature of the target is greater than about 800° C.

46. The method of claim 29, wherein a temperature of the target is less than a temperature of a stream of the aerosol impacting the target.

47. The method of claim 29, wherein a temperature of the target is at least 100° C. less than a temperature of a stream of the aerosol impacting the target.

48. The method of claim 29, wherein a temperature of a stream of the aerosol impacting the target is greater than or equal to about 800° C.

49. The method of claim 29, wherein a temperature of a stream of the aerosol impacting the target is greater than or equal to about 900° C.

50. The method of claim 29, wherein a temperature of a stream of the aerosol close to impacting the target is greater than or equal to about 1,000° and less than or equal to about 1,500° C.

51. The method of claim 29, wherein the reaction chamber comprises convergent walls, and

52. The method of claim 29, further comprising:

53. The method of claim 29, wherein, for a given distance along the reaction chamber:

54. The method of claim 29, wherein, for a given distance along the reaction chamber:

55. The method of claim 29, wherein the first gaseous or vapor phase composition is obtained by heating, under pressure, the first composition contained as pure liquid in a first supply tank,