Vehicle air system having an indicator device and method

• US 20070169627A1
• Filed: 01/26/2006
• Published: 07/26/2007
• Est. Priority Date: 01/26/2006
• Status: Active Grant

• Current Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Original Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Inventors: Fornof, William
• Granted Patent: US 7,544,234 B2
• Time in Patent Office: Days
• US Class Current: 96/108
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 2253/112 Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106
• CPC Class Codes: B01D 2253/20 Organic adsorbents
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 2259/40081 Counter-current
• CPC Class Codes: B01D 2259/40086 by using a purge gas B01D2259/4009 takes precedence
• CPC Class Codes: B01D 2259/4566 for use in transportation means
• CPC Class Codes: B01D 53/0415 Beds in cartridges
• CPC Class Codes: B01D 53/261 by adsorption
• CPC Class Codes: B60T 17/004 Draining and drying devices
• CPC Class Codes: Y10S 55/17 Compressed air water removal
• CPC Class Codes: Y10S 55/34 Indicator and controllers

Abstract

Various compressed air systems for commercial vehicles are disclosed. In one embodiment, a compressed air system is provided that includes a compressor, an air dryer apparatus, a purge reservoir, and an indicator device. The indicator device comprises a moisture-indicating material that is in contact with the purge air within the purge reservoir.

Claims

1. A compressed air system for commercial vehicles, the compressed air system comprising:

a compressor;

an air dryer comprising a desiccant;

a purge reservoir comprising an indicator device; and

wherein the indicator device comprises a moisture-indicating material that is in contact with air within the purge reservoir.

2. The compressed air system of claim 1, wherein the air flows from the desiccant of the air dryer into the purge reservoir and also from the purge reservoir through the desiccant of the air dryer.

3. The compressed air system of claim 1, wherein the air system further comprises an orifice disposed between the desiccant of the air dryer and the purge reservoir, and the orifice restricts the rate of air flow from the purge reservoir to the air dryer.

4. The compressed air system of claim 3, wherein the air system further comprises a check valve disposed between the desiccant of the air dryer and the purge reservoir and the check valve allows air flow from the air dryer through the check valve to the purge reservoir, and prevents air flow from the purge reservoir through the check valve to the air dryer.

5. The compressed air system of claim 1, wherein the indicator device comprises a moisture-indicating material capable of visibly changing from a first color to a second color when air in the purge reservoir has a relative humidity level that is greater than about 10%.

6. The compressed air system of claim 5, wherein the air in the purge reservoir has a relative humidity that is less than about 40%.

7. The compressed air system of claim 1, wherein the indicator device comprises a moisture-indicating material capable of visibly changing from a first color to a second color when air in the purge reservoir has a relative humidity level that is greater than about 20% and less than about 30%.

8. The compressed air system of claim 5, wherein the color of moisture-indicating material visibly reverts back to the first color when the relative humidity of the air in the purge reservoir is about 10% or less.

9. The compressed air system of claim 1, wherein the moisture-indicating material visibly changes color when the when dew point suppression of the air, as measured by the ambient air temperature minus the dew point temperature of the air in the purge reservoir, ranges from about 0°

F. to about 20°

F.

10. The compressed air system of claim 9, wherein the ambient temperature ranges from about −

30°

F. to about 80°

F.

11. The compressed air system of claim 10, wherein the temperature difference, Δ

T between the air at the dryer outlet and the ambient temperature ranges from about 20°

F. to about 60°

F.

12. The compressed air system of claim 1, wherein the moisture-indicating material visibly changes color when the when dew point suppression is less than about 12°

F.

13. The compressed air system of claim 1, wherein the air dryer comprises a dryer housing and the purge reservoir is internal to the dryer housing.

14. The compressed air system of claim 1, wherein the air dryer comprises a dryer housing and the purge reservoir is external to the dryer housing.

15. The compressed air system of claim 1, wherein the moisture-indicating material comprises a hygroscopic material selected from metal salts comprising transition metal and materials in group 6a and 7a of the Periodic Table, organo-metallic salts, and mixtures thereof.

16. The compressed air system of claim 15, wherein the moisture-indicating material further comprises a dye.

17. The compressed air system of claim 1, wherein the moisture-indicating material comprises a hygroscopic material selected from iron salts, copper salts, and mixtures thereof.

18. The compressed air system of claim 1, wherein the moisture-indicating material comprises a porous substrate.

19. The compressed air system of claim 18, wherein the porous substrate comprises silica gel.

20. The compressed air system of claim 1, wherein the indicator device comprises:

a body;

a window; and

wherein the moisture-indicating material is disposed inside the body is viewable through the window.

21. The compressed air system of claim 20, wherein the window is transparent.

22. The compressed air system of claim 20, wherein the window is translucent.

23. The compressed air system of claim 20, wherein body comprises a port.

24. The compressed air system of claim 1, wherein:

air flows from the air dryer into the purge reservoir and from the purge reservoir through the desiccant of the air dryer; and

the indicator device comprises a moisture-indicating material that changes color when the relative humidity of the air in the purge reservoir is greater than about 10%.

25. The compressed air system of claim 24, wherein the moisture-indicating material comprises a hygroscopic material selected from metal salts comprising transition metal and materials in group 6a and 7a of the Periodic Table, organo-metallic salts, and mixtures thereof.

26. A compressed air system for commercial vehicles, the compressed air system comprising:

a compressor;

an air dryer comprising a desiccant;

a purge reservoir;

wherein the purge reservoir comprises a means for monitoring the effectiveness of the desiccant of the dryer based on the moisture level of purge air that flows from the air dryer to the purge reservoir and from the purge reservoir to the air dryer.

27. The compressed air system of claim 26, wherein the means for monitoring the moisture level of the purge air comprises a means for viewing a color change from outside the purge reservoir of the vehicle when the moisture level exceeds a predetermined level or range of levels of moisture.

28. The compressed air system of claim 27, wherein the means for viewing a color change from outside the purge reservoir comprises an indicator device comprising a moisture-indicating material disposed inside the body and viewable through a window.

29. The compressed air system of claim 28, wherein the moisture-indicating material comprises a hygroscopic material selected from the group consisting of:

iron chloride, copper chloride and mixtures thereof.

30. A dryer apparatus for use in commercial vehicles, the dryer apparatus comprising:

a housing;

desiccant disposed within the housing;

a purge reservoir internal to the housing, the purge reservoir comprising purge air that has passed through the desiccant; and

an indicator device comprising moisture-indicating material in communication with the purge air of the purge reservoir.

31. The dryer apparatus of claim 30, wherein the purge reservoir is disposed between a desiccant cartridge containing the desiccant and a wall of the air dryer.

32. The dryer apparatus of claim 30, wherein the air flows from the desiccant of the air dryer into the purge reservoir and also from the purge reservoir through the desiccant of the air dryer such that air flow across the indicator device is in a first direction and a second direction that is opposite the first direction.

33. The dryer apparatus of claim 30, wherein the indicator device comprises a moisture-indicating material capable of visibly changing from a first color to a second color when air in the purge reservoir has a relative humidity level that is greater than about 10%.

34. The dryer apparatus of claim 33, wherein the color of moisture-indicating material visibly reverts back to the first color when the relative humidity of the air in the purge reservoir is about 10% or less.

35. The dryer apparatus of claim 30, wherein the moisture-indicating material visibly changes color at a dew point suppression that ranges from about 0°

F. to about 20°

F.

36. The dryer apparatus of claim 35, wherein the ambient temperature ranges from about −

30°

F. to about 80°

F.

37. The dryer apparatus of claim 36, wherein the temperature difference, Δ

T between the air at the dryer outlet and the ambient temperature ranges from about 20°

F. to about 60°

F.

38. The dryer apparatus of claim 30, wherein the moisture-indicating material comprises a hygroscopic material selected from metal salts comprising transition metal and materials in group 6a and 7a of the Periodic Table, organo-metallic salts and mixtures thereof.

39. The dryer apparatus of claim 30, wherein the indicator device comprises:

a body;

a window; and

wherein the moisture-indicating material is disposed inside the body is viewable through the window.

40. The dryer apparatus of claim 39, wherein the moisture-indicating material comprises a hygroscopic material selected from metal salts comprising transition metal and materials in group 6a and 7a of the Periodic Table, organo-metallic salts, and mixtures thereof.

41. A method of monitoring the moisture in the air of a vehicle air system, the method comprising:

pressurizing a purge reservoir with purge air that has passed through a desiccant; and

passing the purge air into contact with a moisture-indicating material that is capable of visibly changes color when the relative humidity of the air in the purge reservoir is greater than about 10%

42. The method of claim 41, wherein the moisture-indicating material comprises a hygroscopic material selected from metal salts comprising transition metal and materials in group 6a and 7a of the Periodic Table, organo-metallic salts and mixtures thereof.

43. An indicator device comprising:

a body;

a window;

a moisture-indicating material disposed inside the body and viewable through the window; and

a permeable layer which allows air to contact the moisture-indicating material;

44. The indicator device of claim 43, further comprising:

a retainer; and

wherein the permeable layer is disposed between the moisture indicating material and the retainer.

45. The indicator device of claim 43, wherein the body comprises a port.

46. The indicator device of claim 43, wherein the moisture indicating material is a hygroscopic material which changes from a first color to a second color when the relative humidity of the air contacting the hygroscopic material is at least about 10%.

47. The indicator device of claim 46, wherein the relative humidity of the air contacting the hygroscopic material is less than about 40%.

48. The indicator device of claim 46, wherein the moisture-indicating material, once changed to the second color, reverts back to the first color when the relative humidity of the air contacting the hygroscopic material is less than about 10%.

49. The indicator device of claim 43, wherein the moisture-indicating material comprises a hygroscopic material is selected from metal salts comprising transition metal and materials in group 6a and 7a of the Periodic Table, organo-metallic salts, and mixtures thereof.

50. The indicator device of claim 43, wherein the moisture indicating material comprises a material selected from iron salts and copper salts.

51. A purge reservoir comprising:

an indicator device comprising a moisture-indicating material.

52. The purge reservoir of claim 51, wherein the indicator device comprises a body and a window, and the moisture-indicating material is disposed within the body and viewable through a window.

53. The purge reservoir of claim 51, wherein the moisture indicating material is a hygroscopic material which changes from a first color to a second color when the relative humidity of the air contacting the hygroscopic material is at least about 10%.

54. The purge reservoir of claim 53, wherein the moisture-indicating material, once changed to the second color, reverts back to the first color when the relative humidity of the air contacting the hygroscopic material is less than about 10%.

55. A desiccant canister comprising:

a desiccant; and

an indicator device comprising a body, a window, and a moisture-indicating material which is disposed within the body and viewable through a window.

56. The desiccant canister of claim 55, wherein the desiccant canister is replaceable.

57. The desiccant canister of claim 56, wherein the desiccant canister is disposed within an air dryer and the indicator device comprises a moisture-indicating material that is viewable through the air dryer.

58. The desiccant canister of claim 56, wherein the moisture indicating material is a hygroscopic material which changes from a first color to a second color when the relative humidity of the air contacting the hygroscopic material is at least about 10%.