Hydrocarbon leak sensor

• US 5,264,368 A
• Filed: 01/17/1992
• Issued: 11/23/1993
• Est. Priority Date: 10/10/1990
• Status: Expired due to Term

• Current Assignee: Boston Advanced Technologies, Inc. (Global Technovations, Inc.)
• Original Assignee: Boston Advanced Technologies, Inc. (Global Technovations, Inc.)
• Inventors: DeJesus, Stephen, Harrison, Harvey, Hopkins, T. Eric, Clarke, Richard H., Chung, Wai
• Primary Examiner(s): Housel, James C.
• Assistant Examiner(s): Soderquist, Arlen
• Application Number:
  US07/822,097
• Time in Patent Office: 676 Days
• Field of Search: 73/49.1, 73/49.2, 73/61.61, 73/61.48, 200/61.04, 200/84 B, 200/84 C, 250/301, 250/302, 307/118, 340/605, 340/623, 340/624, 422/68.1, 422/82.05, 422/82.08, 422/82.09, 436/3, 436/27, 436/56, 436/60, 436/139, 436/172
• US Class Current: 436/3
• CPC Class Codes: G01M 3/047 with photo-electrical detection means, e.g. using optical fibres
• CPC Class Codes: G01M 3/38 by using light G01M3/02 takes precedence
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: Y10T 436/13 Tracers or tags
• CPC Class Codes: Y10T 436/21 Hydrocarbon

Abstract

Method and apparatus for detecting and/or monitoring the presence of hydrocarbons in a fluid medium at a remote location, by sensing the presence of hydrocarbon-based fluid in the fluid medium in the remote location, generating a signal indicative of the sensed fluid, and transmitting the signal to monitoring means for indication of hydrocarbon contamination. The apparatus has multiple sensors at different vertical levels for sensing the fluid medium at a plurality of levels within the fluid.

Claims

1. A system for monitoring for the presence of hydrocarbon-based fluid in a remote location, the system comprising a

a sensor device,

said sensor device having means for sensing the presence of hydrocarbon-based fluid at at least two different vertical levels in a fluid mass in a remote location, and for generating a sense signal indicative of said sensed fluid at said different levels, said means comprising at least one sensor element at each of said two different levels,

wireless communication means for wirelessly communicating said sense signal to a monitoring station for monitoring of the presence of hydrocarbon-based fluid at said different levels within said remote location, and

housing means for commonly housing of said device and said communication means in said remote location.

2. The system of claim 1 wherein said communication means comprises a wireless transmitter, conditioning electronics, and a power source.

3. The system of claim 2 wherein said power source comprises a timing circuit for reduction of power consumption.

4. The system of claim 3 wherein said power source comprises a rechargeable battery.

5. The system of claim 1 wherein said housing means extends along a floatation axis and said sensor elements are located of different axial locations along said axis for sensing said different levels relative to the surface of said fluid mass.

6. The system of claim 1 wherein said sensor device is a floating device.

7. The system of claim 6 wherein said housing means comprises a buoyancy adjustment means for adjusting the buoyancy of said floating sensor device.

8. The system of claim 6 further comprising means for detecting when the sensor device is not floating.

9. The system of claim 6 wherein said housing has a bottom comprising an ice rejection means for lifting said sensor device out of ice forming at said bottom.

10. The system of claim 9 wherein said ice rejection means comprises a material layer on said housing bottom.

11. The system of claim 1 wherein said means for sensing is for sensing hydrocarbon-based fluids based on detection of fluorescent components of said fluids.

12. The system of claim 11 wherein said means for sensing comprises a housing defining a sample chamber, irradiation means for irradiating a fluid sample drawn into the sample chamber from said fluid, and detection means for detecting fluorescence exhibited by the irradiated sample.

13. The system of claim 12 wherein said means for sensing further comprises a hydrophobic absorption means for communication between said sample chamber and said fluid.

14. The system of claim 13 wherein said absorption means comprises a porous wick.

15. The system of claim 14 wherein said sensor device is a device for floating at the surface of said fluid, and said sensor device further comprises a housing having vents opening out above said fluid surface when said sensor device is floating at said fluid surface, and wherein said wicks are vented by said vents above said fluid surface.

16. The system of claim 1 wherein said communication means further comprises a wireless transmitter for transmission of said sense signal, said system further comprising a cooperating receiver means, said receiver means for wireless receipt of said transmitted sense signal and for communication of said received transmitted sense signal to said monitoring station.

17. The system of claim 16 wherein said remote location is a bore hole and said receiver further comprises housing means for location of said receiver adjacent to said sensor device in said bore hole.

18. The system of claim 16 wherein said system further comprises means for detecting a layer of hydrocarbon-based fuel accumulated in an overflow pan for a hydrocarbon-based fuel pump.

19. The system of claim 16 wherein said system further comprises means for detecting a layer of hydrocarbon-based fuel accumulated in an interstitial chamber within a double walled tank.

20. The system of claim 16 wherein said system further comprises means for detecting a layer of hydrocarbon-based fuel accumulated in a sump.

21. The system of claim 1 wherein said sensor device extends along a floatation axis and further comprises guidance means for guiding said sensor device along said axis as said sensor device floats on said fluid.

22. The system of claim 21 further comprising sensor means for detecting when said sensor device is not floating.

23. A system for monitoring for the presence of hydrocarbon-based fluid in a fluid medium in a remote location, the system comprising

a sensor device for monitoring a fluid medium, said sensor device including

a buoyant housing, said housing having a calibration index, and

means mounted in said housing for sensing the presence of hydrocarbon-based fluid in a remote location and for generating a sense signal indicative of said sensed fluid, said means including a plurality of fluid level sensor elements mounted at different respective axial locations relative to said housing for sensing a plurality of depths of said fluid relative to said calibration index.

24. The system of claim 23 wherein said calibration index is a draft line at which said sensor device is afloat in said fluid, and said plurality of fluid level sensor elements are mounted at respective distances from said draft line.

25. The system of claim 24 wherein said sensor device has a buoyancy adjustment means for changing the location of said draft line relative to said plurality of fluid level sensor elements.

26. A method for monitoring for the presence of hydrocarbon-based fluid in a fluid medium in a remote location, comprising the steps of

providing a housed sensing device, including at least two sensor elements, for sensing the presence of hydrocarbon-based fluid in a remote location at at least two different vertical levels in a fluid mass by using at least one of said sensor element at each of said two different levels,

generating a sense signal indicative of said sensed fluid at said different levels, and

wirelessly transmitting said sense signal to monitoring means for monitoring the presence of said hydrocarbon-based fluid at said different levels within said remote location.

27. A method for monitoring for the presence of hydrocarbon-based fluid in a fluid medium in a remote location, comprising the steps of

monitoring a fluid medium in a remote location with a sensor device having a buoyant housing, said housing having a calibration index, and

sensing, with a plurality of axially separated fluid level sensor elements mounted on said housing, the presence of hydrocarbon-based fluid in said fluid medium, and generating a sense signal indicative of said sensed hydrocarbon-based fluid, for monitoring the presence of said hydrocarbon-based fluid at a plurality of depths in said fluid medium relative to said calibration index.

28. The method of claim 27 wherein said calibration index is a draft line at which said sensor device is afloat in said fluid, and said plurality of fluid level sensor elements are mounted at respective distances from said draft line.